Note: Descriptions are shown in the official language in which they were submitted.
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
MOLDING MEDIA AND PROCESS OF MAKING SAME
TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION
The present invention provides a method of producing resin stabilized
polymeric fiber molding media useful for a variety of purposes, including as
thermal and
acoustical insulation, and in structural load-bearing parts. The method of the
invention
can lower the cost and weight of producing such media while still maintaining
the
necessary mechanical and acoustical properties. The method of the invention
further
provides a resinated polymeric fiber molding media that can have environmental
advantages over glass fiber and foam mats. The method of the invention further
provides
a means of incorporating a thermosetting binder system into a thermoplastic
polymer fiber
fleece or nonwoven, thereby allowing the finished product to be molded in a
one step hot
or cold molding process.
BACKGROUND OF THE INVENTION
Fiber and foam panels or mats are well known and widely used throughout
the construction and automotive industries as thermal and sound insulating
material. Such
panels or mats are manufactured from a wide variety of fibers and foams, such
as
compressed wood, cork, cane, rock wool, gypsum, or glass fibers, and foams.
Typically,
the formed mats are used in wall or ceiling construction as sound absorbers in
mechanical
suspension systems, and sound insulating and transmittance reducing media.
During the 1970s and early 1980s, the transportation industry primarily
used glass fiber batts to provide sound insulation in vehicles. However, as a
result of
irntation to workers handling the mats the industry has moved to using less
irritating foam
mats. Unfortunately, although the foam is less irritating and is roughly
comparable in
cost to the glass fiber batts, the foam has the disadvantage that it is not
easily recyclable.
Most foam fiber mats are typically a multilayer product of glass and foam;
thus the main impediment to recycling of foam is the fact that the layers of
glass and foam
would need to be separated before recycling could be attempted. An added
disadvantage
with foam is that due to the layering in foam the fiber mats can be more
complicated to
mold.
Recently, attempts have been made to produce insulating mats for the
transportation industry from polyester since, unlike foam, the polyester fiber
mats would
-1-
CA 02274168 1999-06-07
WO 98/30375 PCTIUS98/00446
be recyclable. To date, the polyester fiber mats produced for the
transportation industry
have a basis weight of about 140-144 gm/ft2 (about 1507-1550 gm/m2) and range
between
I 40-160 gm/ft2 ( 1507-172 gm/m2). Due to the high basis weight such polyester
f ber mats
are uneconomical and have not been adopted by the industry despite the
environmental
advantages. Thus a need exists for a method of producing an economical
insulating fiber
molding media that meets or exceeds environmental and handling criteria while
still
maintaining physical property requirements. These needs are met by the resin
stabilized
polymeric fiber molding media of the invention.
SUMMARY OF THE INVENTION
The present invention provides a moldable sound and thermal insulating
material exhibiting good sound absorption and dimensional stability. The sound
absorption material of the present invention is formed by a number of
different
embodiments. In one embodiment the sound absorption material is formed of a
polymeric
fiber mat stabilized with a cured resinous foam. In addition, the present
invention
I 5 provides a method of forming such fiber mats by foaming resin through a
polymer fiber
mat and curing the resin. The resinated polymeric mat of the invention also
allows for a
single step hot molding process to be used even when applying a foamed back
facing.
The contour molded article may be used in an application which demands a
structural, acoustic or thermal performance. For example, in the interior of
an automobile,
medium duty, heavy duty and other machines used in transportation. This
includes
examples such as, a thermal insulative or sound absorptive device under the
hood; a
thermal insulative or sound absorptive device at the fire wall; a thermal
insulative or
sound absorptive device in the doors and instrument panels; a thermal
insulative or sound
absorptive device behind the rear seat; a thermal insulative or sound
absorptive device in
the trunk; a thermal insulative or sound absorptive device in the A, B and C
pillars; a
thermal insulative or sound absorptive device in the roof such as a headliner;
and a
thermal insulative or sound absorptive device in the floor area above and
below the floor.
Accordingly, the present invention provides a resin stabilized polymeric
fiber molding media that is believed to exhibit low irritability when handled
and to be
easily recyclable, and that exhibits good mechanical strength and acoustical
insulation
properties, which can be produced economically due to the reduced amount of
polymeric
fibers needed in the mat as a result of the mechanical strength.
-2-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
The invention additionally provides an unresinated polymeric fiber
molding media that is reinforced with fibers ranging from straw and other
natural fibers to
thermoplastics such as polypropylene and polyester. The unresinated polymeric
fiber is
useful in applications wherein folding of the insulating material results in
disruption of the
resin solids.
The invention optionally further provides a sound absorption material that
is formed as a layered composite. This layered composite sound absorption
material is
made up of a glass fiber wool or textile core sandwiched between two polymer
fiber mat
layers. The three layer composite is stabilized with a cured resinous foam.
This optional
composite is believed to exhibit low irritation when handled, and is believed
to be easily
recycled by stripping out the glass fiber core from the sandwich. This
composite also
provides good mechanical strength and acoustical properties.
Accordingly, the present invention provides a means for "dialing-in" a
desired stiffness into the polymer molding media, while maintaining good
acoustic,
thermal and ease of manufacturability properties, and the entire process is
economically
more competitive than alternate media.
The invention additionally provides a polymeric fiber molding media that
is not incorporated with resin, but is reinforced with fibers ranging from
straw, kenaf,
flax, hemp, jute, sisal and other natural fibers to thermoplastics such as
polyolefin,
polyester, copolyester, and thermosets such as aramid, melamine-formaldehyde
and glass.
The polymeric fiber molding media is useful in applications where in the
forming of the
molding media during hot molding may interfere with the engineered performance
of the
end-use product.
The invention also provides the means for producing a nonwoven polymer
fiber molding media with the incorporation of glass fibers at the core or the
surface, and
mechanically entangling the 3D structure so as to be able to produce a product
that when
resinated provides the high strength and high temperature resistance
performance of glass,
but the formability of polymer fibers, in a cold molding tool. This structure
enables the
production of a 3D nonwoven composite, when impregnated with a thermosetting
resin,
allows the use of a formed product to be used at continuous use temperatures
exceeding
250°F (121°C).
-3-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
An additional embodiment of the invention includes the forced air
distribution and blending in controlled air velocity feeding system for the
production of a
randomly oriented nonwoven fleece or batt that has 95% of the blended fibers
oriented in
the "z" direction or an angle close to; this random distribution and vertical
orientation of
blended fibers of the composition range extremes of high concentration
fiber/low
concentration fiber from 99.9/0.1 to 0.1 /99.9. The thickness of the formed
fleece range
from O.I" (2.54 mm) to 50" (1270 mm) height. The weight of the fleece can
range from
g/m2 to 5000 g/m2. The nonwoven batt is produced with the blend of polymer
fibers
and glass fibers and the finished batt is incorporated with a thermosetting or
thermoplastic
10 resin system which allows the molding of a formed shape with a one step or
hot tool. The
invention allows the means to design the exact combination of acoustic,
thermal,
structural and use temperatures while maintaining a low cost for the finished
product.
A further embodiment of the invention allows for the incorporation of
thermosetting or self crosslinking thermoplastic binder powders into the
polymer batt,
I 5 thereby allowing for the cold molding or hot molding capability of the
nonwoven polymer
batt into a 3D structure that has good thermal and acoustic insulative
properties, and is
low in odor and volatile emissions during the hot molding process.
One additional embodiment is directed to an encapsulated heat molded
laminate comprising multiple layers. Number of layers ranges from 3 on up with
5 to 7
being typically preferred. Seven or more layers may be used so as to tune the
acoustical
performance. This multi-layered composite may be comprised of: a facer or
shaper web
layer; PET fibers and sheath fibers capable of heat setting; an optional glue
web capable
of binding to the adjacent core board or mat (sound absorbing Layer, e.g.,
mineral wool);
another optional glue web; a front facer or shaper web, and a finish fabric.
This
composite is useful as a decorative embossed acoustical absorber for ceilings
and walls
that is not only more cost effective to produce, but also provides better
acoustical
properties and aesthetics due to the moldability. In addition, the physically
irritating
layers such as mineral fiber wool cores can be totally encapsulated so as to
make the final
product more useable.
The present invention allows for many embodiments depending on the
application. In addition, the acoustical properties of the resulting
composites can be
varied by changes or increases in porosity (Rayls). In particular, the
acoustical
-4-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
performance is easily tuned for maximizing sound absorption by varying air
porosity
(Rayls) of the cover material and/or core material. In order to change the
porosity, it is
preferred that changes be made to either thickness, surface area, surface
density, fiber
diameter, fiber shape, or weight/amount of fibers.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a representation of a dispenser for foaming resin.
Figure 2 is a cross section taken through section 2-2 of Figure 1.
Figure 3 is a representation of a second embodiment of the dispenser of
Figure 1.
Figure 4 is a side elevation view of the method and apparatus for
impregnating a fibrous web.
Figure S is a partial side cross-sectional view of the apparatus of Figure 4.
Figure 6 is a partial plan view of the apparatus of Figure 4.
Figure 7 is a side elevation view of an alternative embodiment of the
apparatus of Figure 4.
Figure 8 is a partial side elevation view of the fibrous material being
impregnated.
Figure 9 is a drawing of an automobile showing positioning of a headliner
( 1 ) and a hoodliner (2) made according to the present invention.
Figure 10 is a graph showing the results of testing for the effect of binder
fiber contained in the polymer fiber mats, on sound absorption.
Figure 11 is a graph showing the results of the effect of selected molding
temperatures on sound absorption tests carried out on '/4 and '/4" diameter
samples.
Figure 12 shows a representative cross-sectional view of the mufti-layered
laminate embodiment prior to molding ( 12a). Figure ( 12b) is a representative
cross-
sectional drawing of the laminate tile after molding with heat and/or
pressure.
Figure 13 shows graphs of impedance testing and airflow resistance testing
on molding ceiling tiles produced as a mufti-layered laminate.
Figure 14 depicts typical fiber orientation for tensile and strength property
measurements, for single fiber and 3D bonded nonwoven polymer batt.
Figure 15 shows acoustic performance of polymeric batt formed in cold
tool compared to open cell urethane foam.
-5-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
Figure 16 depicts the probable orientation of the liquid binder impregnated
in the 3D nonwoven polymer and batt.
Figure 17 depicts the probable orientation of the sheath-core binding
polymer in the 3D nonwoven polymer and batt.
Figure 18 depicts the probable orientation of low melting bonding polymer
fiber in the 3D nonwoven polymer and batt.
Figure 19 depicts the probable orientation of powder bonding polymer in
the 3D nonwoven polymer and batt.
DETAILED DESCRIPTION OF THE
PREFERRED EMBODIMENTS OF THE INVENTION
The method of the present invention comprises providing a mat formed of
polymeric fibers; foaming a resin; dispersing the foamed resin throughout the
mat;
removing the excess resin foam; and drying the resin stabilized polymeric mat
to form a
molding media. The method further includes molding the resinated polymeric
media at an
elevated temperature into a part. Standard molding processes may be used
wherein a
portion of the mat is moved into a hot press at an elevated temperature (for
example,
between about 300-600°F [about 149-316°C]). In the standard
process, the molding mat
is then moved to a second hot press where a foamed back facing is added at a
temperature
of about 350°F (about 177°C). In a preferred embodiment,
however, the molding process
is carried out in one step at about 350-400°F (about 177-204°C).
In a particularly
preferred embodiment, the one-step molding process is carried out at
350°F (I77°C) or
375°F (i91°C).
In one embodiment, the layered composite of the invention is made up of a
glass fiber batt sandwiched between two layers of polymeric fiber mat. Whereas
in
another embodiment, it is comprised of a preentangled batt of polymer and
glass fibers.
The layers are sandwiched together by any of the methods used in the art for
combining
fiber mats together. Typically, the layers are mechanically stacked one on top
of the other
and processed as with the single layer embodiment.
Glass fiber batts to be used in the layered composite of the invention may
be any glass fiber batt useful for forming insulation products, and a basic,
bisected wool
batt from the Owens Corning plant in Newark, Ohio appears to work well.
Nonwoven
-6-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
glass fiber batts produced by a rotary process with weights ranging from about
10 gm/ft2
(108 gm/mz) to about 200 gm/ft2 (2153 gm/mz) also work well.
Polymeric mats to be used in the invention may be any polymeric fibrous
mat useful for forming insulation products. For example, mats may be made from
polyester, copolyester, polypropylene, polyimide, polyetherimide,
thermoplastics,
polycaprolactam, nylon 6, nylon 66, polyolefms, phenolic resins and any blends
thereof.
In a preferred embodiment, the polymeric mat is made from a nonwoven polyester
as in
the substantially thermoses polyester roll good obtainable from Vita Olympic,
a division
of Prelude Fiber. In a preferred embodiment, the polymeric batt is made in a
nonwoven
carding or garnering process as obtained from Hobbs Bonded Fibers or HDK
Industries or
Vita Inc. The polymer fiber batt manufactured on an air-lay process such as on
DOA
machinery of Wels, Austria is also suitable for this process. However the
selection of the
polymer batt is engineered such that it is able to withstand the incorporation
of the liquid
thermosetting or thermoplastic binder, as well as not interfere with the
finishing process
during binder impregnation and subsequent cold or hot molding forming process.
Whatever polymer or polyester fiber is selected, it must be able to withstand
the
temperatures of a drying oven without shrinking or turning brittle. A typical
drying oven
temperature can be about 300° Fahrenheit (about 149°C) and
ranges from 250-350°F ( 121-
177°C). In addition, the preferred polymeric fiber mats selected
generally have about 10-
20% binder fiber, such as CelbondTM binder fiber manufactured by Hoechst
Celanese, for
thicker mats such as mats made without a glass layer. Preferred thinner
polymeric fiber
mats, such as used in composite mats, generally have about 20-40% binder
fiber.
However in the unresinated polymeric fiber mats which are reinforced with
fiber, the
binder fiber is present in about 10-75%.
In another embodiment the preferred polymer fiber batts have to
incorporate a sheath-core bonding fiber such as manufactured by tJNITIKA or
Trevira
Inc., or lower melting binding fiber such as manufactured by WELLMAN, Inc.,
Foss
Manufacturing Co., DuPont or Asahi Inc. The presence of the binding fibers is
to provide
a 3D stable structure that is dimensionally strong during the foam
impregnation process,
as well as preserve the vertical or "z" orientation of the polymer fibers for
providing a 3D
molded contoured part that exhibits good flexibility during assembly at the
end use point
of installation. The bonding fibers also preserve the acoustic and thermal
performance of
_7_
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
the structure after the incorporation of the binder system. The range of
bonding fiber in
the polymer batt can range from S - 95%, and in the preferred batts selected
for the present
invention, the binding fibers range from 5 to 25%.
When fibers are used to reinforce the mats, the fibers may be any natural
fiber, such as may be obtained from push brooms. The fibers may also be from
straw or
even thermoplastics such as polypropylene or polyester. A preferred fiber for
reinforcement is spunbonded polyester obtained from Reemay (a BBA Nonwoven
Company located in Old Hickory, Tennessee).
When using fibers to reinforce the batt without the use of glass fiber mats,
natural fiber such as Palmyra, Sisal, Jute and Kenaf or any other natural bast
of leaf fiber
can be substituted for the above. The fibers for reinforcement may also be
preformed as a
nonwoven batt such as supplied by BBA Inc., Freudenberg Nonwovens or Wendell
Textile Inc. When using fibers for reinforcement, glass or thermosetting
fibers can be
used. In the preferred invention, glass fibers such as produced in a rotary
process with
1-3% cured binder, textile glass filaments, melamine formaldehyde fibers, such
as
produced by BASF Inc., and aramid, polyimide and polyethedmide fibers.
Resins that can be used herein include thermoplastics, resoles or low
temperature phenolics, low odor and low emission formaldehyde copolymer
systems and
thermoset systems two component and self crosslinking. Almost any resin
material that
can be foamed or air-diluted can be used with the foam applicator. Usually
aqueous based
resinous resins such as arylics, phenolics, vinyls, urea and polyethelene are
used to
impregnate the fibrous material. However, it should be noted that other
thermoplastic and
thermoset resins having either an aqueous or solvent base can be used to
impregnate the
fibrous web if the resins are capable of being foamed. It is also possible to
mix various
resins together and apply the combined or mixed resins to the fibrous web. The
resins can
be mixed to obtain the desired properties for the resin system that is to be
applied to the
fibrous web. It is also possible to mix fillers in with the resin material.
The fillers can be
used to reduce the amount of resin required, to add weight to the impregnated
fibrous web
or to achieve a particular property in the impregnated web.
A preferred resin comprises an aqueous dispersion of urea, a resole, and an
amino alkyl silane or silane hydrolysis product and a surfactant. In general,
the silane or
silane hydrolysis product should constitute in weight percent, from about 0.01
percent to
_g_
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
about 3 percent of the total solids in the composition, urea should constitute
from about 3
percent to about 60 percent, the phenolic resole should constitute from about
40 percent to
about 97 percent, and the surfactant about 0.25 to about 10 percent. The
preferred ranges
are silane about 0.02 percent to about 2 percent, urea about 5 percent to
about 45 percent,
phenolic resole about 50 percent to about 90 percent, and the surfactant about
1.0 percent
to about 8 percent.
A variety of phenolic resoles may be used in a composition according to
the invention. Thus, the resole can be the partial condensation product of any
suitable
phenol with any suitable aldehyde (for a discussion of resoles, see Martin,
The Chemistry
of Phenolic Resin, John Wiley & Sons, Inc., New York 1956, particularly pages
87-98,
and cited references). As a practical matter, however, a resole curable to an
infusible
resite is usually preferred for use in connection with polymeric fibers so
that at least a
significant amount of a trifunctional phenol, usually hydroxy benzene for
economic
reasons, is preferably employed. Formaldehyde is the preferred aldehyde not
only for
economic reasons, but also because of the greater simplicity of its chemical
reactions with
a phenol. Most desirably, the resole is produced by reaction of formaldehyde
with phenol
(hydroxy benzene) and usually in proportions from 1 mol to 4.5 mots,
preferably from
about 1.75 mots to about 4.2 mots of formaldehyde per mol of phenol.
Metallic cations, particularly highly alkaline metallic cations, if present in
a phenolic resole applied to a polymer can be detrimental, apparently causing
deterioration both of the fibers themselves and of the resite resin. Phenolic
resoles are
usually prepared in the presence of highly alkaline condensing agents so that
the metallic
cations thereof are preferably either removed from the resole prior to use,
for example by
cation exchange treatment of the resole, or converted to a form in which they
are
harmless. As an example of the latter technique, the condensation to produce
the resole
can be carried out in the presence of barium hydroxide as a condensing agent,
and the
barium hydroxide can be neutralized, after completion of the partial
condensation to form
the resole, with sulfuric acid or the like to produce barium sulfate. The
barium sulfate can
be left in the resole, since it is harmless, provided that it has a
sufficiently small particle
size so as not to impair handling of the resole, or it can be removed by
filtration.
An improved resole composition, useful in the invention comprises an
amino alkyl silane or silane hydrolysis product. In general, it has been found
that any
-9-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
commercially available amino alkyl silane is highly advantageous in such a
resin
composition. Such silanes have the general formula:
R-Si-O-R'NH-n
wherein R is an amino alkyl radical chemically bonded to the silicon atom, R'
is an alkyl
radical having from 1 to 4 carbon atoms, and n is an integer from 1 to 3,
inclusive,
optimum results have been achieved using a silane having the general formula:
NHZCzH4NHC3H6Si(--OCH3)3
Excellent results have also been achieved using organo functional silanes
such as gamma-amino-propyltriethoxy silane, glycidoxypropyltrimethoxy silane
and 3-
methacryloxypropyltrimethoxy silane. The preferred silane is 3-amino-
propyltriethoxy
silane, commercially available from OSi Specialties of Witco under the trade
designation
A 1100. A preferred class of such silanes is one wherein R in the foregoing
general
formula has the formula HZN-R" where R= is an alkylene radical having from 2
to 6
carbon atoms. Another such preferred class is one wherein R has the formula:
HzN-R"-NH-R"'
wherein R" and R"' are both alkylene radicals having from 2 to 6 carbon atoms.
Selection of the proper surfactant is very important in this resin
application. The surfactant must have the proper wetting properties so that
the resin will
penetrate the polymeric pack. Some of the resin must penetrate to the center
of the
polymeric pack. However, having a layer near the surface that is resin-rich
gives a
smoother finish to the cured part. After application, the fiber and resin can
be dried in a
RF oven and stored until ready to mold into the finished product. During the
cure cycle,
the surfactant in the surface layer is decomposed by the cure heat. This gives
a molded
product with a hydrophobic surface. Water-based adhesives can therefore be
applied to
the surface of the molded fiber without the adhesive soaking or wicking into
the interior
of the molded article. This allows the use of much less adhesive when used to
apply a
finish or appearance coating to the molded article. Two surfactants which have
the
properties needed for this use are Aerosol OT-75 and polystep B-11. Aerosol OT-
75 is a
product of Cytec and is a dioctyl ester of sodium sulfosuccinic acid. Polystep
B-11 is a
product of Stepon Chemical Company, Northfield, IL, and is ammonium lauryl
ether
sulfate. Both of these surfactants will be decomposed in the surface layer by
the curing
cycle used in this invention thereby giving a hydrophobic surface.
-10-
CA 02274168 1999-06-07
WO 98/30375 PCTIUS98100446
Various acid and base compounds can be used to control the pH of the
resin solution to give it the desired stability. A wide range of resin to
glass fiber weight
ratios can be used to make useable products. These can vary from about 5
weight percent
binder to more than 60 weight percent resin. The more useful range is from
about 8
weight percent to about 45 weight percent binder in the molded product. The
density of
the molded product can also vary over a large range. Useful products can be as
light as 1
pound per cubic food ( 16.018 kg/m3) and as heavy as 45-50 pounds per cubic
foot
(720.831-800.923 kg/m').
The resin may also contain hydrocarbon polymers such as latex. The
addition of latexes is useful for applications requiring increased elasticity.
For example,
in applications where the molding media is folded, it is useful to add
elasticity so as to
avoid creasing problems.
Once the resin is selected, it is then dispensed through an apparatus that
will foam the resin. Any such apparatus may be used as long as the resin is
foamed. In a
preferred embodiment, the apparatus used to foam the resin is the one
described in United
States Patent No. 4,570,859 assigned to Owens Corning, incorporated by
reference herein.
In particular, the apparatus used is as shown in Figures 1-3.
Figures 1 and 2 show a chamber or dispensing head 1, having an apertured
dispensing wall 2, apertures 3, being positioned therein. The dispensing head
is adapted
with conduit 4 opening thereunto for the introduction of the material or resin
to be
dispensed through the apertures.
Positioned within the head is carrier 6 comprising a support shaft 7 on
which the expandable member 8 is carried in any suitable manner. The
expandable
member is positioned along the length of the head by means of crank 9 which
acts to
move the carrier along threaded shaft 10. The expandable member is carried,
for
example, on side track and supports 1 l and is expandable downward
therebetween.
Positioned between the expandable member and the apertures can be resilient
member or
gasket, 12. Upon expansion of the expandable member downward by the
introduction of
a fluid through inlet 13 and hose 14, a compressible member such as a gasket
12 is forced
against the outlet apertures to substantially limit flow therethrough from the
head to any
desired rate, including total shut-off.
-il-
CA 02274168 1999-06-07
WO 98130375 PCT/US98/00446
Affixed to the gasket is plate 20 which, in turn, is carried on springs 15 and
16. Upon inflation of the expandable member, these springs are placed in
compression as
the gasket and plate move against the apertures. Upon deflation of the
expandable
member, the expandable member moves away from the apertures, and the springs
relax
such that the plate moves upwardly carrying the gasket with it to open flow
through the
apertures from the dispenser.
Referring to Figure 3, there is shown a plurality of expandable members 8
and 8A carried on a common, but extended, carrier 6. The second expandable
member
8A, is adapted in a manner similar to that of a single carrier of Figure 1
with the total
length of the carrier being less than, equal to, of the width of the
dispenser, thus enabling
the carrier to be positioned at any point along the width of the head. If
desired, a second
and independent fluid inlet can be affixed to each expandable member to
inflate the
members independently of each other and provision can be supplied to move the
members
individually along the longitudinal axis of the dispenser.
In addition, the chamber can be departmentalized such that from each
compartment is dispensed a different material, the expandable member being
arbitrarily
positioned in each compartment. Any suitable expandable member can be employed
in
this invention. One example of a preferred embodiment is a pressure power unit
termed
the "Windjammer" available from Merriman Products, Inc., Jackson, Michigan.
The
expandable member will not be of such a size as to limit flow of the dispenser
through the
dispensing head. The above discussion regarding the dispenser of a foamed
resin is taken
from United States Patent No. 4,956,409, assigned to Owens Corning, herein
incorporated
by reference.
The resin is then dispersed as a foam throughout the fiber. A preferred
embodiment uses an apparatus for impregnating a fibrous web such as disclosed
in United
States Patent No. 4,288,475, incorporated by reference herein. (The following
discussion
of the apparatus for impregnating a fibrous web is taken from U.S. Patent No.
4,288,475.)
A conveyor is provided for advancing a fibrous web or mat having a first and a
second
surface. An applicator is provided for applying a foamed resin to the first
surface of the
fibrous web and the resin seals the first surface of the web. A vacuum chamber
is
positioned adjacent to the second surface of the web. The vacuum chamber
contains a
narrow slot adjacent to the second surface of the web for applying a vacuum to
the web.
-12-
CA 02274168 1999-06-07
WO 98/30375 PCT/LTS98/00446
The vacuum acts upon the web to reduce the thickness of the web and to draw
the foamed
binder into the web to impregnate the web. The specific features of the
process will be
more fully understood by referring to the attached drawings in connection with
the
following description.
Figure 4 shows an embodiment of an impregnator 1 of this invention. The
impregnator contains a first porous of foraminous conveyor 3 for conveying the
fibrous
material that is to be impregnated. The conveyor can be constructed of a woven
or mesh
type belt provided the belt is porous. The conveyor is supported and advanced
by rollers
5 in a manner well known in the art. Positioned adjacent to one side of the
first conveyor
3 is a foam applicator 9. The foam applicator 9 is positioned adjacent the
side of the first
conveyor upon which the material to be impregnated is positioned. The foam
applicator 9
is positioned with respect to the conveyor so that the material to be
impregnated can pass
beneath the foam applicator as it is advanced by the first conveyor 3.
Positioned on the
opposite side of the first conveyor 3 from the foam applicator 9 is a vacuum
chamber 13.
1 S The vacuum chamber 13 is positioned adjacent to the side of the first
conveyor 3 that is
opposite to the side of the conveyor that is used to convey the material to be
impregnated.
The vacuum chamber is positioned with respect to the first conveyor 3 so that
the vacuum
chamber is substantially opposite to the foam applicator 9.
At the discharge end of the first conveyor 3 there is positioned a second
porous of foraminous conveyor 19. The second conveyor 19 is supported and
driven by
rollers 21 in a manner which is well known in the art. The second conveyor 19
is
positioned with respect to the first conveyor 3 so that the material to be
impregnated
advances onto the second conveyor. As the material advances onto the second
conveyor
the surface of the material that was spaced apart from the first conveyor 3
will be
positioned on the surface of the second conveyor 19. The surface of the
material that was
in contact with the surface of the first conveyor 3 will now be spaced apart
from the
surface of the second conveyor 19. In other words, the fibrous material is
reversed with
respect to the surface of the conveyor as the fibrous material advances onto
the second
conveyor 19.
The foam applicator 9 is positioned adjacent the surface of the second
conveyor 19 upon which the material to be impregnated is positioned. The foam
applicator 9 is positioned with respect to the second conveyor 19 in
substantially the same
-13-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
manner the foam applicator 9 was positioned with respect to the first conveyor
3.
Positioned on the opposite side of the second conveyor 19 from the foam
applicator 9 is a
vacuum chamber 13. The vacuum chamber 13 is positioned in substantially the
same
manner as the vacuum chamber 13 was positioned with respect to the first
conveyor 3.
The foam applicators 9, associated with the first and second conveyors,
contain an inlet pipe 35 that is connected to a foaming head 37 by a conduit
36. The
foaming head foams the resin and supplies the foamed resin to the foam
applicators 9.
Valves 39 can be positioned between the foam applicators 9 and the foaming
head 37 for
controlling the supply of foamed resin to the foam applicators. The resin for
the foaming
head 37 is supplied from a mix tank 43. A pump 45 is used to supply the resin
from the
mix tank 43 to the foaming head 37. The resin material enters the foaming head
through
an inlet pipe 49. The inlet pipe 49 also contains an air inlet 51 through
which air can be
supplied to the resin that is being pumped to the foaming head 37. A motor 43
is
provided for operating the foaming head 37.
The vacuum chambers 13, associated with the first and second conveyors,
contain two vacuum chambers and each chamber is connected by a vacuum line 27
to a
vacuum and storage chamber 29. A valve 31 can be positioned between the vacuum
chamber 13 and the vacuum and storage chamber 29 to control the supply of
vacuum to
the chambers 13. The combination vacuum and storage chambers 29 contain
discharge
openings 56 and the discharge openings 57 are connected by conduit 59 to the
mix tank
43. The combination vacuum and storage chambers 29 each have a pump 63 for
discharging material from the chamber 29 through the discharge opening 57.
Positioned adjacent the second conveyor 19 is a third porous or foraminous
conveyor 69. The third conveyor 69 is supported upon and is driven by rollers
71 in a
manner that is well known in the art. The third conveyor 69 passes through a
drying oven
75. The drying oven contains drying chambers 77 that are positioned on each
side of the
third conveyor 69. The drying chambers 77 are connected to a supply conduit 79
and the
supply conduits are connected to a header 81. The header 81 is connected to a
furnace 83
by a distribution duct 85. The furnace 83 can contain a blower 87 having an
inlet opening
89. The drying oven 75 contains exhaust openings 90 through which the exhaust
from the
drying oven is discharged. The exhaust openings 90 can be connected to the
inlet opening
89 for the blower 87.
-14-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98100446
Positioned at the end of the third conveyor 69 is a collection station 95 for
collecting the fibrous material that has been impregnated on the impregnator
1. The
collection station 95 can comprise a collet or spindle upon which the fibrous
material may
be wound into a package.
S The details of the foam applicators 9 and vacuum chambers 13 will be
more fully understood by referring to Figures 5 and 6. The foam applicator has
two side
walls that are substantially parallel to the direction of travel or
advancement of the
conveyor, two end walls that are substantially perpendicular to the direction
of
advancement of the conveyor and a top wall that is substantially parallel to
the surface of
the conveyor upon which the material to be impregnated is positioned. Almost
any resin
material that can be foamed or air-diluted can be used with the foam
applicator 9. Usually
aqueous based resinous resins such as acrylics, phenolics, vinyls, urea and
polyethelene
are used to impregnate the fibrous material. However, it should be noted that
other
thermoplastic and thermoset resins having either an aqueous or foam
applicator, i.e., the
portion of the foam applicator that is positioned adjacent to the surface of
the conveyor, is
open. Thus, the foam applicator 9 defines a chamber that is open on one side
and the
open side of the chamber is adj acent the conveyor and the fibrous material to
be
impregnated. The end walls of the foam applicators are positioned so that they
terminate
above the surface of the conveyor. Sufficient space is provided between the
surface of the
conveyor and the end walls of the foam applicator to allow the fibrous
material to advance
on the conveyor beneath the foam applicator. The sidewalk 32 of the foam
applicator
extend down to the surface of the conveyor, also, as shown in Figure 6, the
sidewalk 32
are spaced apart from the edges of the fibrous material. A space 33 is defined
between the
sidewalls 32 and the edge of the fibrous material.
The foam inlet pipe 3 S extends into the foam applicator and terminates in a
header 99. The header 99 is disposed substantially perpendicular to the
direction of
advancement of the conveyor and the header 99 extends substantially across the
width of
the conveyor. The header 99 contains a plurality of orifices 103. The orifices
103 are
substantially equally spaced along the header and extend substantially along
the entire
length of the header. The orifices 103 are positioned in the portion of the
header 99 that is
closest to the surface of the conveyor and the material to be impregnated. The
direction of
discharge from the orifices 103 is towards the surfaces of the conveyor and
substantially
-15-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
perpendicular to the direction of advancement of the conveyor. The foam
discharge
header 99 and the orifice 103 are disposed in the foam applicator 9 so that
they are in
spaced apart relationship with the conveyor and the material to be
impregnated.
The foam inlet pipe 35 is also connected to conduits 107. Conduits 107
terminate in discharge nozzles 109. The discharge nozzles 109 are oriented to
discharge
material in a direction that is substantially parallel to the direction of
advancement of the
conveyor. The discharge nozzles I09 are disposed approximately at the ends of
the
discharge header 99. There is a discharge nozzle 109 at each end of the header
99. The
discharge nozzles 109 are also positioned in close proximity to the edges of
the conveyor.
The discharge nozzles 109 are positioned between the header 99 and the surface
of the
material to be impregnated. In fact, the discharge nozzles 109 are disposed in
close
proximate relationship to the surface of the material to be impregnated. As
shown in
Figure 5 the discharge nozzles 109 can be positioned to discharge material
onto the
advancing fibrous material before the orifices 103 in the header 99 discharges
material
onto the advancing fibrous material.
Positioned downstream from the header 99 and discharge nozzles 109 is a
foam spreader 115. The foam spreader is disposed substantially perpendicular
to the
direction of the advancement of the conveyor and the spreader extends from
sidewall to
sidewall of the foam applicator 9. The foam spreader 115 normally terminates
so that it is
in spaced apart relationship with the conveyor and the fibrous material to be
impregnated.
The portion of the foam spreader 1 I S that is in closest proximity to the
conveyor and
fibrous material contains an adjustable blade 117. The adjustable blade 117 is
adjustably
secured to the spreader I 15 by the securement means 119. The securement means
119
adjustably secures the blade 117 so that the blade can be adjusted in a
direction which is
substantially perpendicular to the direction of the advancement of the
conveyor.
Movement of the blade 117 adjusts the distance between the surface of the
conveyor and
the blade 117.
Positioned downstream from the foam spreader is a first roller 123 and a
second roller I25. The first roller 123 is rotatably positioned on rod 127.
The rod 127 is
positioned in the foam applicator 9 so that the first roller 123 will be in
contact with the
surface of the material that is to be impregnated as the first roller 123
rotates. The second
roller 125 is rotatably positioned so that it rests upon the surface of the
first roller 123 that
-16-
CA 02274168 1999-06-07
WO 98/30375 PCTlUS98/00446
is spaced apart from the surface of the conveyor and the end wall 129 of the
foam
applicator 9. The first and second rollers are positioned so that their
longitudinal axes are
substantially perpendicular to the direction of advancement of the conveyor.
The first and
second roller also extend substantially across the entire width of the
conveyor. The first
S roller 123 is free to move on the rod 127 in a direction that is
perpendicular to the surface
of the conveyor. Thus, the first roller is free to remove with respect to the
surface of the
conveyor. As the second roller 125 is positioned on the first roller, the
second roller will
move with any movement of the first roller.
The end wall 129 of the foam applicator 9 terminates at a position that is
spaced apart from the fibrous material that is being advanced on the conveyor.
A squeegy
133 is positioned on the end wall 129 and extends down to the upper surface of
the
fibrous material. The squeegy is normally constructed on a resilient or
pliable material
that can bend or deflect as the fibrous material advances.
Positioned on the opposite side of the conveyor from the foam applicator 9
is a vacuum chamber 13. The vacuum chamber 13 contains a first chamber 139 and
a
second chamber 141. The first and second chambers are separated by a wall 143.
Thus,
there are two separate chambers within the vacuum chamber 13. The vacuum
chamber 13
is connected to plate 147 and plate 147 is positioned immediately adjacent the
conveyor.
The plate 147 and vacuum chamber 13 extend substantially across the width of
the
conveyor. On each side of the plate 147 the conveyor is supported by members
144. The
members 144 extend substantially across the width of the conveyor. A seal 145
is
positioned between the plate 147 and the members 144. The seals are positioned
to
prevent the flow of air between the plate 147 and the members 144. Located in
the plate
147 are slot 149 and slot 150. The slots pass through the plate 147 and place
the interior
of vacuum chamber 13 in communication with the underside of the conveyor. Slot
149 is
positioned so that it is in communication with the first chamber 139 and slot
150 is in
communication with the second chamber 143 in the vacuum chamber 13. The slots
149
and 150 extend substantially across the width of the conveyor and the
longitudinal axes of
the slots are substantially parallel and substantially perpendicular to the
direction of
advancement of the conveyor. The slots are usually relatively narrow, having a
width of
about 0.02 to about 0.125 of an inch (about 0.50$ to about 3.175 mm). However,
it has
been found in practice that slots having a width of about 0.040 to about 0.050
of an inch
- I 7-
CA 02274168 1999-06-07
WO 98/30375 PCT/C1S98/00446
(about 1.016 to about 1.27 mm) will normally work satisfactorily in
impregnating fibrous
material. The slots are positioned in the plate so that there is a space of
about 0.25 of an
inch to about 2 inches (about 6.35 to about 51 mm) between the slots. The
vacuum
chamber 13 and plate 147 are disposed with respect to the conveyor so that the
slots are
positioned on the opposite side of the conveyor from the foam applicator 9.
The slot 150
is positioned substantially beneath the first roller 123 in the foam
applicator 9. A vacuum
line 27 extends from the first chamber 139 and the second chamber 141 for
connecting
these chambers to a source of vacuum.
The operation of the impregnator will be more fully understood by
referring to Figures 4, 5 and 6. Fibrous material 155 is advanced from a
distribution
station 157 onto the first porous or foraminous conveyor 3. The fibrous
material can
contain some resin material to hold the fibrous material in the form of a web
or mat. The
advancement of the conveyor 3 acts to advance the fibrous material so that it
moves along
the advancing conveyor. The fibrous material passes under the foam applicator
9. The
foam applicator is positioned in spaced apart relationship with one side of
the conveyor 3
so that the fibrous material is free to pass beneath the foam applicator.
In the foam applicator 9 a foam resin material 161 is applied to the surface
of the fibrous material. The resinous material is foamed or air diluted in the
foaming head
37 prior to being applied to the fibrous materials. During the foaming process
air bubbles
are entrained into the resin to cause the resin to foam. The foaming process,
therefore,
produces a resin having a cellular structure with the bubbles forming the
cells in the resin.
The foamed resin material is applied to the fibrous material through the
orifices 103 in the
header 99 and the discharge nozzle 109 located on the ends of conduits 107. A
sufficient
quantity of foam resin material supplied to the surface of the fibrous
material to insure
that the entire surface of this fibrous material is coated. The discharge
nozzles 109 are
positioned substantially along the sides of the conveyor and the material to
be
impregnated. Accordingly, more foamed resin is applied along the edges of the
fibrous
material as the material advance through the foam applicator 9. A portion of
the resin
material will be deposited in the space 33 between the sidewalls 32 of the
foam applicator
and the edges of the fibrous material. The foamed resin deposited in the space
33 will act
to seal the edges of the fibrous material. Figures 2 and 3 show how additional
foamed
resin is applied at the edges of the fibrous material by the nozzles 109.
-18-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
In most applications more foamed resin material is applied to the fibrous
material than is actually required to impregnate the fibrous material.
Accordingly, a foam
spreader 115 is positioned in the foam applicator 9 and the foam spreader has
an
adjustable blade 117 positioned in adjacent spaced apart relationship to the
surface of the
S fibrous material. The foam spreader 115 acts to distribute the foam across
the entire
width of the fibrous material so that there will be an adequate distribution
of foamed resin
on the entire surface of the fibrous material. The adjustable blade 117 is
positioned to
allow a measured amount of foamed resin material to pass under the foam
spreader and to
advance with the fibrous material. Thus, the foam spreader and adjustable
blade act to
apply a measured amount of foamed resin material to the surface of the fibrous
material.
As the fibrous material advances along the conveyor 3 the fibrous material
comes under the influence of the vacuum chamber 13. The slot 149 in plate 147
communicates with first chamber 139 in the vacuum chamber 13. The first
chamber 139
is connected to a source of vacuum through vacuum line 27. Accordingly, a zone
of
reduced pressure is created along the slot 149 which communicates with the
first chamber
139. The conveyor 3 advancing above the slots 149 is porous so that the affect
of the
reduced pressure, created by the slot 149, passes through the porous conveyor.
The
reduced pressure acts upon the fibrous material and causes it to compress or
be drawn
towards the slot 149 as the fibrous material advances over the slot 149. The
fibrous
material is compressed by the reduced pressure because the foamed resin
material on the
surface of the fibrous material seals the upper surface and edges of the
fibrous material.
As the fibrous material is sealed by the resin, the reduced pressure acts upon
the fibrous
material and draws it towards the slot 149. Accordingly, the reduced pressure
in the first
chamber 139 compresses the fibrous material. In practice, it has been found
that the
fibrous material will be reduced to about 3/4 to about 1/10 of its original
thickness as it
passes over the slot 149 that communicates with the first chamber. The
reduction in
thickness of the fibrous material is primarily a function of the thickness of
the material,
the density of the material and the strength of the reduced pressure. However,
it should be
noted that if a very thin material is being impregnated that there may be very
little
compression of the fibrous material as it advances past the slot 149.
The zone of reduced pressure created by slot 149 also causes the foamed
resin material 161 to be drawn into the fibrous material to impregnate the
fibrous material.
-19-
CA 02274168 1999-06-07
WO 98/30375 PCTIUS98/00446
In fact, a portion of the foamed resin material 161 can be drawn through the
fibrous
material, through the porous conveyor, through the slot 149 and into the first
chamber
139. After passing the slot 149 which is in communication with the first
chamber 139 the
fibrous material is substantially impregnated with the foamed resin material
161.
When the fibrous material is compressed or reduced in thickness, the
fibrous material becomes more uniform with respect to the resistance of flow
of a fluid
through the fibrous material. Accordingly, the foamed resin material will be
drawn
through a more uniform fibrous material and the impregnation of the fibrous
material will
be more uniform as a result of the compression of the fibrous material. In
practice, it has
been found that most fibrous materials will have to be compressed to at least
'/2 of their
original thickness to significantly improve the resistance to flow of a fluid
through the
fibrous material. The degree of compression of the fibrous material can be
controlled by
controlling the strength of the vacuum or reduced pressure in the vacuum
chamber 13.
The vacuum can be controlled by adjusting the valve 31 between the vacuum
chamber 13
1 S and the vacuum and storage chamber 29. By controlling the level of vacuum
in vacuum
chamber 13 to be compatible with the fibrous material and foamed resin being
used, the
impregnation of the fibrous material can be optimized.
The fibrous material then passes over a second zone of reduced pressure
which is created by slot 1 SO which is in communication with the second
chamber 141 of
the vacuum chamber 13. The second zone of reduced pressure acts to hold the
fibrous
material in its state of reduced thickness and draws additional foamed resin
material to the
interior of the fibrous material. The zone of reduce pressure created by slot
150 can also
act to compress the fibrous material as the fibrous material advances past the
slot.
However, any such additional compression will usually be very slight. In
fact, portions of the foamed resin material may pass through the fibrous
material, through
the porous conveyor, through the slot 150 and into the interior of the second
chamber 141.
As the fibrous material advances past the slot 150 the fibrous material is
usually
completely impregnated with the foamed resin.
The slot 150 and zone of reduced pressure created by the slot, may not be
necessary to draw additional foamed resin material into the fibrous material.
The fibrous
material may be completely impregnated after advancing over the zone of
reduced
pressure created by slot 149. However, the slot 150 is available to supply an
additional
-20-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
zone of reduced pressure if such an additional zone is required to complete
the
impregnation of the fibrous material. However, the zone of reduced pressure
created by
slot 150 does provide an additional important function in that it helps to
maintain the
fibrous material in contact with the conveyor. When the fibrous material is
held against
the conveyor, a seal between the fibrous material and conveyor is created. The
seal acts to
prevent air from being drawn into the slots 149 and 150 from the environment
around the
foam applicator 9 and vacuum chamber 13. In addition, the seals between the
vacuum
chamber 13 and the members supporting the conveyor also act to prevent air
from the
environment around the foam applicator and vacuum chamber from being drawn
into the
slots 149 and 150. When air is not drawn between the fibrous material and
conveyor, the
zone of reduced pressure from slot 149 is more effective in compressing the
fibrous
material and in drawing foamed resin into the fibrous material. Thus, the slot
150 will
normally be connected to a source of reduced pressure to help hold the fibrous
material
against the conveyor even if the slot 1 SO is not required to further
impregnate the fibrous
1 S material with the foamed resin. The valve 31 can be used to adj ust the
strength of the
reduced pressure connected to slot 150 depending on whether the reduced
pressure is
being used to further impregnate the fibrous material or to hold the fibrous
material
against the surface of the conveyor.
When the fibrous material passes over slots 149 and 150 the zone of
reduced pressure from the slots diverges, as shown in Figure 8, as it acts
upon the fibrous
material. The effect of the zone of reduced pressure fans out from the slot
and acts upon a
wider area of the fibrous material. In constructing the vacuum chamber 13 it
is important
that the slots 149 and 1 S 0 be positioned so that the diverging effect of the
reduced
pressure from the slots will overlap in the fibrous material. By having the
effect of the
zones of reduced pressure from slots 149 and 150 overlap the fibrous material
will
continually be under the influence of the reduced pressure as the fibrous
material passes
over the slots 149 and 150. Accordingly, the fibrous material will be held
against the
conveyor by the overlapping effect of the reduced pressure, a good seal will
exist between
the fibrous material and the conveyor and the reduced pressure from slots 149
and i 50
will be more effective in impregnating the fibrous material.
The zones of reduced pressure created by slots 149 and 1 SO must be
sufficiently strong to create a pressure differential in the fibrous material
that will draw
-21-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
the foamed resin material into the fibrous material. The widths of the slots
149 and 150
can be set so that there will be a sufficient pressure differential created by
the slots.
Generally, the narrower the slot, the greater the pressure differential that
will be created
by the slots. In addition, valves 31 can be adjusted to control the strength
of the vacuum
supplied to the slots 149 and 150.
Positioned above the slot 150 is the first roller 123 and the second roller
125. The first and second rollers are positioned in the foam applicator to
keep excess
foamed resin material from remaining on the surface of the fibrous material
after the
fibrous material passes the slot 150. The first roller 123 is mounted on the
rod 127 so that
the roller 123 is free to move in a direction perpendicular to the surface of
the fibrous
material. Therefore, if there is a bump or depression in the fibrous material
the first roller
123 can move to stay in contact with the surface of the fibrous material. The
movement
of the first roller 123 keeps the roller from being damaged and keeps the
roller from
damaging the fibrous material if there is a lump or other problem in the
fibrous materials.
As the impregnated fibrous material advances along the conveyors from
the foam applicator 13 there is a squeegy 133 which is positioned on the end
wall 129 of
the foam applicator. The squeegy 133 is constructed of a resilient material
and the end of
the squeegy is in contact with the surface of the fibrous material. The
squeegy is
positioned at the end of the foam applicator to remove any excess foamed resin
that may
remain on the surface of the fibrous material after the fibrous material has
passed through
the foam applicator.
After passing through the foam applicator 9 and vacuum chamber 13
associated with the first conveyor 3 the impregnated fibrous material advances
along the
first conveyor until it comes into contact with the second conveyor 19. The
impregnated
fibrous material then is transferred to the second porous conveyor 19. The
second
conveyor 19 is positioned so that surface of the impregnated fibrous material
that was
spaced apart from the surface of the first conveyor 3 will be in contact with
the surface of
the second conveyor 19. And the surface of the impregnated fibrous material
that was in
contact with the surface of the first conveyor 3 will now be spaced apart from
the surface
of the second conveyor 19. The impregnated fibrous material advances along the
second
conveyor 19 until it comes in contact with a foam applicator 9 and a vacuum
chamber 13
which are substantially similar in position and operation to the foam
applicator 9 and the
-22-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
vacuum chamber 13 associated with the first conveyor 3. As the impregnated
fibrous
material passes between the foam applicator 9 and vacuum chamber 13 associated
with
the second conveyor 19, foamed resin material can again be applied to the
fibrous
material. The application of the foam resin material and the impregnation of
the fibrous
material will be substantially the same as the process described in connection
with the
first conveyor 3. However, the foamed resin material will be drawn into the
fibrous
material in the opposite direction to that shown in respect to first conveyor
3. By
changing the direction of impregnation of the fibrous material the uniformity
of the
impregnation will be improved. The second impregnation step shown in
connection with
the second conveyor 19 may not be required in the impregnation of all fibrous
materials.
In fact, the numbers of foam applicators and vacuum chambers associated with
the
impregnation process can be varied to achieve the desired level of
impregnation for the
fibrous material and foamed resin being used.
The first chamber 139 and second chamber 141 of the vacuum chambers
13 are connected to a vacuum and storage chamber 29 by means of vacuum line
27. It
should be noted that the first chamber 139 and second chamber 141 of each
vacuum
chamber 13 is connected to a separate vacuum and storage chamber by a separate
vacuum
line 27. The vacuum and storage chambers 29 supply the source of negative
pressure or
vacuum for the vacuum chamber 13. This source of vacuum is supplied to the
vacuum
chamber 13 by vacuum line 27. The chambers 29 are, however, also storage
chambers.
When the fibrous material is subjected to the reduced pressure or vacuum of
the first
chamber 139 or second chamber 141 the reduced pressure causes the foamed resin
to
move into the fibrous material and impregnate the fibrous material. As
previously
described some of the foamed resin material may pass through the fibrous
material and be
drawn into the first or second chambers of the vacuum chamber 13. The foamed
resin is
drawn through the first and second chambers and into vacuum line 27 by the
reduced
pressure or vacuum created in the combination vacuum and storage chambers 29.
Thus,
the foamed resin material that is drawn into the vacuum chamber 13 passes
through
vacuum line 27 and into the combination vacuum and storage chambers 29. In the
chamber 29 the resin material is separated out and positioned in a storage
area in the
chamber. The collected resin material can then be discharged through discharge
openings
57 in the chambers 29 into conduit 59 which empties into the mix tank 43. The
resin
-23-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
material is discharged from the chambers 29 by pumps 63 which are connected to
each of
the individual vacuum and storage chambers. A valve can be fitted between the
discharge
opening 57 and the conduit 59 to control the flow of the resin from the
discharge and
storage chambers 29 to the mix tank 43. In this fashion the resin that passes
through the
fibrous material and into the vacuum chamber 13 can be collected in the
chambers 29 and
then recycled into the mix tank 43 for reuse in impregnating the fibrous
material.
In the mix tank 43 the resin material collected in the chambers 29 is mixed
with new resin material. The mixture of resin material in tank 43 is pumped
through a
conduit 49 by pump 45 into a foaming head 3 7. Air can be introduced into the
conduit 49
and into the resin through air inlet S 1. The air inlet connects to the
conduit 49 at a point
in close proximity to where the conduit enters the foaming head. In the
foaming head 37
the combination of the resin material and air is foamed. A suitable motor 53
is provided
for driving the foaming head 37. The foamed resin material is supplied to the
foam
applicator by a conduit 35. Valve 39 can be positioned between the foaming
head and the
1 S foam applicators to control the flow of the foam resin to the foam
applicators.
The foamed resin is particularly well suited for impregnating a web of
fibrous material because of the bubbles or cells formed in the resin during
foaming. The
bubbles become trapped or caught in the interstice between the fibers of the
fibrous
material. The trapping of the bubbles allows a higher percentage of resin to
be retained in
the fibrous material. Using a foamed resin it has been found that up to about
50% to
about 60% by weight of the impregnated fibrous material can be comprised of
resin.
However, in practice it has been found that it is usually only necessary to
apply about 8%
to about 45% by weight of resin material to the fibrous material. In a
preferred
embodiment the resin material is about 8% to about 35% by weight of resin to
the fibrous
material.
From the second conveyor 19, the impregnated fibrous material advances
to the third conveyor 69. As the impregnated fibrous material advances along
the third
conveyor 69 it passes into a drying oven 75. The drying oven 75 has a
plurality of drying
chambers 77 positioned therein. The drying chambers are constructed so that
there is a
chamber on each side of the third conveyor 79. The drying chambers are
connected to a
supply conduit 79 and the supply conduit is connected to a header 81. The
header 81 is
connected to a furnace 83 by a distribution duct 85. A blower 87 is connected
to the
-24-
CA 02274168 1999-06-07
WO 98J30375 PCT/US98/00446
furnace 83 for forcing hot air or other heated gaseous material up the
distribution duct 85
into the header 81 through the supply conduit 79 and into the drying chamber
77. The
drying chambers 77 are arranged so that the heated air or gaseous material
will pass
through the impregnated fibrous material to dry the foam resin. In drying the
foam resin
the heated air or gaseous material removes the aqueous or liquid portion of
the foam resin
and leaves the solid resin in position within the fibrous material. Exhaust
openings 90 are
provided in the drying oven 75 through which exhaust gases can be removed from
the
drying oven. The exhaust gases removed through the exhaust openings 90 can be
recirculated so that they flow back to the blower 87 which is associated with
the furnace
83. In this manner the hot exhaust gases from the drying oven 75 can be
recirculated
through the furnace and reused to dry the impregnated fibrous material. The
bubble or
cell structure of the foamed resin increases the surface area of the aqueous
or liquid
portion of the resin. Accordingly, there is more surface area of the aqueous
or liquid
material that will be contacted by the heated drying fluid. The increased
surface area
allows the aqueous or liquid portion to be removed from the resinous material
using less
energy. The drying oven 75 removes the aqueous or liquid portion of the resin
material
and leaves the solid resin material in the fibrous web. Therefore, when the
impregnated
fibrous material leaves the drying oven 75 it is impregnated with a dried
resin material.
As the aqueous portion of the foamed resin is being removed in the drying
oven 75 the fibrous material begins to recover its original thickness. The
fibrous material
begins to expand because the dryer resin material does not have as much weight
or
adhesive force to hold the fibrous material in a compressed state. When
substantially all
of the aqueous material has been removed from the resin by the drying oven the
fibrous
material will have recovered substantially its original thickness. Therefore,
the drying
oven 75 restores the fibrous material to substantially its full thickness. It
should be noted
that the drying oven 75 only removes the aqueous or liquid material from the
resin and
that the resin is not being cured in the drying oven.
After the fibrous material has been impregnated, dried and collected, the
fibrous material can be further processed to form finished products. As is
discussed in
more detail below, the impregnated fibrous material can be cut to size, molded
to change
its contour and further heated to cure the resin on the fibrous material.
Curing the resin
-25-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
will cause the resin material to become rigid and to hold the fibrous material
in a desired
shape or form.
Figure 7 shows another embodiment for a vacuum chamber that can be
used with the present invention. A vacuum chamber 171 is shown that has a
first chamber
173, a second chamber 175 and a third chamber 177. The three chambers are
separated by
wall 179 and wall 181. The first chamber 173 contains a slot 183 in the top
wall of the
chamber. The second chamber 175 contains a slot 185 in the top wall of the
chamber.
The third chamber 177 contains a slot 187 in the top wall of the chamber. The
vacuum
chamber 171 is positioned in substantially the same manner and operates in
substantially
the same manner as the previously described vacuum chamber 13. However, in
vacuum
chamber 171, there is an additional chamber and slot for applying a zone of
reduced
pressure to a fibrous material to be impregnated.
The additional chamber and slot used in vacuum chamber 171 allows a
zone of reduced pressure to be placed over a wider area of the fibrous
material to be
impregnated. The larger zone of reduced pressure allows more foamed resin
material to
be drawn into the fibrous material as the fibrous material passes over the
vacuum chamber
171. Thus, more complete impregnation will occur as the fibrous material is
passed over
the vacuum chamber 171 or the fibrous material can be advanced at a higher
rate of speed
over the vacuum chamber 171 and receive the same degree of impregnation.
Although vacuum chambers have been described as having 2 and 3
chambers with each chamber containing a slot, it should be noted that the
vacuum
chamber can be constructed with any number of chambers and slots, however, it
has been
found to be advantageous to construct the vacuum chamber with at least two
regions of
reduced pressure that can act upon the fibrous material to be impregnated. It
should also
be noted, that any number of foam applicators and vacuum chambers can be
utilized to
impregnate the fibrous material.
As demonstrated by the above discussion, there are a number of options for
producing the insulating material of the present invention. In general, when
using the
polymeric fiber mat, it may be produced:
(1) as a single layer that is resin stabilized;
(2) as a single layer that is reinforced with fibers applied to either the
top, bottom or both sides of the polymeric fiber layer;
-26-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98100446
(3) as a single layer with preentangled reinforcement fibers either in
the surface or core;
(4) as a combination of options ( 1 ) and (2); or
(S) as a combination of options (1) and (3).
S With option one polymeric mats are preferably in the range of 70-90
gms/ftZ (7S3-969 gm/m2) and the resin is added between S-40% of the original
polymeric
mat weight. Thus for polymeric mats produced as described in option 1, the
final basis
weight ranges from about 70-13 0 gm/ftz (about 7S 3-13 99 gm/m2). For option
two, the
fiber used as reinforcement is between S-30% of the original mat weight
resulting in a
final basis weight from about 70 to 1 SO gm/ft2 (about 7S3-161 S gm/m2).
Option three
uses the combination of resin and fiber to stabilize and reinforce the
polymeric mat;
therefore, the final basis weight may range from about 70 to 180 gm/ft2 (about
7S 3-193 8
g~mz)
The molding media, preferably with a final basis weight of about 40-120
gm/ft2 (about 431-1292 gm/mz) and more preferably 60-100 gm/ft2 (646-1076
gm/m2), is
then molded into a final part such as an automotive headliner ( 1 ) or
hoodliner (2} as is
shown in Figure 9. The molding may be carried out by either cold molding or
hot
molding processes. The preferred method is to unroll the molding media and
then carry
out a single-step hot molding with a polymer facing. The molding media may be
cut to
the outline of the desired part, such as a headliner, hoodliner, side pillars
or rear deck
package tray by any means. A preferred means is a water jet cutter. Once the
part is
molded subassemblies such as, for a headliner, sun visors, handgrips, coat
hooks, dome
lights and even duct work can then be attached.
In another embodiment of option one, polymeric nonwoven batts are
2S preferable in the range of 2S-99 g/ft2 (269-1066 g/m2) and the binder
incorporated
between S-4S% of the original polymeric batt weight. In an embodiment of
option three,
the reinforcement fiber ranges between 2 and 99% of the original batt weight,
with the
preferred weights ranging between 2 and 4S%. In an embodiment of option four,
the
combination of binder and fiber is used to three dimensionally stabilize and
reinforce the
polymeric batt. The molding media, preferably with the final basis weight of
about 2S-
1 SO g/ft2 (about 269-161 S g/mz), and for vehicle headliner, preferably in
the range of SO-
100 g/ft2 (S38-1076 g/m2), is then formed into a vehicle headliner (1) or
hoodliner (2) as
-27-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
shown in Figure 9. The polymeric fiber batt can be formed thermally in a cold
press or
hot press by compression. The preferred method feeds an unwound roll of
polymeric
media into a preheated hot press for molding and forming, or is preheated
prior to
introduction into a cold press for forming into the desired shape. The molding
media may
be cut into the outline of the shape of the desired fixture such as a
Headliner, Hoodliner,
Package Tray, Door liner, Pillar Insert, Firewall insulator, Exhaust
insulator, Trunk liner,
Floor pan liner by any means. A preferred means of cutting is by Laser or
water jet.
After the cut part is formed, additional subassembly fixtures such as sun
visors, hand
grips, coat hooks, dome lights and ventilation duct work can be attached to
the said
headliner.
In another embodiment, a preentangled batt of polymer fiber and glass
fiber is precut into shapes, and several layers of the polymer and glass fiber
batt are
formed into preferred shape by hot or cold molding. A preferred embodiment
comprises
the batt to be composed of 50% rotary glass fiber and 50% reclaimed textile
fiber waste
(polyester or polypropylene) and after foaming with the binder, is cut into
desire shape,
and 1-10 layers of known weight are formed in a hot or cold tool for forming
into the
desired shape. The thus molded part exhibits good acoustic and thermal
properties, and
can be used at temperatures above 250°F ( 121 °C).
In another embodiment, a mufti-layered laminate is produced. The layers
are sandwiched together by any of the methods used in the art for combining
fiber mats
together. Typically, the layers are mechanically stacked one on top of the
other and
processed as with the single layer embodiment. A preferred embodiment
comprises six
layers: a back facer web/shaper; a glue web; a core board absorber; a second
glue web; a
front facer web/shaper; and a decorative fabric facer/web.
For the back and/or front facer layers, materials such as polyester fiber
containing added heat moldable fibers may be used. Preferred polyester fibers
are those
that may be purchased from Vita/Olympic as polyester terphthalate (PET)
containing
Celbond sheathed fibers for heat molding. The density range for the layer is
from about
0.25 (about 4.005 kg/m3) to about 4.0 (about 64.074 kg/m') with 1.5 lb/ft3
(24.028 kg/m3)
being preferred. The thickness of the typical layer ranges from about 1/8"
(about 3.175
mm) to about 3 inches (about 76 mm) with '/4" (6.4 mm) being preferred. Fiber
diameter
ranges from about 2 to about 10 denier average with 4 being the average denier
preferred.
-28-
CA 02274168 1999-06-07
WO 98/30375 PCT/IJS98/00446
When using PET, the content of moldable fibers ranges from about S% to about
70% with
30% being typical.
As for the glue web layer (2nd and 4th), this layer is optional, and may be
made of any heat activated glue. A preferred glue is a porous glue such as
Charnette~.
Typically, the glue layer is not a continuous glue film since a continuous
layer may block
dissipation of sound energy by the acoustical layer or core board. The glue
layer may be
left out for flammability reasons, cost or to minimize complexity.
The core board or acoustical absorbing layer is typically comprised of
either: ( 1 ) a standard insulation material such as a glass fiber batt, glass
wool, or textile
glass; (2) a layered component made up of a glass fiber batt, or sandwiched
between
layers of polymeric fiber mat; or (3) a resin stabilized version of ( 1 ) or
(2). A preferred
glass fiber batt, is a basic bisected wool batt; in a particularly preferred
embodiment the
glass fiber insulation product Miraflex~ obtained from Owens Corning is used.
In
addition to the above, the core board or acoustical absorbing layer may also
be comprised
of metal or mineral fiber, aerated concrete, gypsum board, or foams such as
polyamide or
any polymer.
The decorative fabric web layer is comprised of woven and/or nonwoven
fabrics that are stretched and set so as to conform to the contours of the
laminate.
Preferred materials are standard polyesters, polyester blends, cottons, wool,
wool blends,
etc. The thickness of the layer ranges from about 0.010 inches to about 0.250
inches
(about 0.254mm to about 6.35 mm) with 0.0625 inches (1.588 mm) being
preferred.
Manufacture of the mufti-layered laminate embodiment may be carried out
by the standard techniques used for production of ceiling and wall tiles. For
example,
process methods such as heated hydraulic presses, batch process or continuous
may be
used.
Example I
Preparation of Resole Resin
A resole resin composition was prepared as follows. A catalyst slurry was
made with 1000 grams of water and 160 grams of calcium hydroxide. 6,470 grams
of 52
percent formaldehyde and 2,480 grams of phenol were placed in the reaction
vessel. This
mixture was agitated for 5 minutes and then the temperature is raised to
115°F (46°C).
While the temperature was held at 115°F (46°C), the catalyst
slurry was added over a 2
-29-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
hour period. The temperature was raised to 125°F (52°C )for 1
hour. The temperature
was then raised to 150°F (66°C ) and held at this temperature
until the percent free phenol
decreased below 12.5 percent. This took about 2-3 hours. Then the resin was
cooled to
7°F (-14°C ) and stored until needed.
Resins also manufactured such as those supplied by Borden Chemical,
Georgia Pacific or Neste Inc., can be used here. This embodiment uses Borden
resins
IB809B, IB915B, IB402B, catalyzed by Sodium, Calcium and Potassium catalysts.
The
reduction of odor and emissions is further enhanced by the addition of
melamine polymer,
and other ingredients such as Lignin sulfonate manufactured by Georgia
Pacific.
Extending the curing kinetics of the resin system, in a preferred embodiment
was further
accomplished by the addition of self crosslinking latex polymers such as those
supplied
by BF Goodrich, Goodyear and Air Products and Chemicals, Inc. Other
embodiments use
Airflex 192, Airflex 911, Vinac 884 and Flexbond 974.
Example II
Preparation of Resin Mix
The following was then placed in a reaction vessel: 3 63 grams of urea, 2.5
grams of silane and 5 grams of sodium hexamethyl phosphate. This was mixed for
5
minutes and 606 grams of the resole from Example I were added. This was
stirred for 2
hours then the pH is adjusted to 75 with a combination of dimmonium phosphate
and
ammonium sulfate, or with phosphoric acid. This was mixed for 10 minutes and
the pH
adjusted to 8.0 to 8.5 with ammonia and 15 grams of Aerosol OT-75 was then
mixed in.
Note that surfactants manufactured by Air Products and Chemicals, Inc. may
also be used
in place of OT-75. The resin was then ready for use.
Example III
Table I shows the resin formulation foamed throughout a polyester fiber
mat. Samples were prepared using that formulation and tested. Sample 1 a is a
'/4 inch
(6.35 mm) cold-molded polyester fiber with no resin. Sample 1 b is a '/2 inch
( 12.7 mm)
version of sample 1 a. Sample 2a is a '/4 inch (6.3 5 mm) molded polyester
with the resin
foamed throughout; sample 2b is '/z inch ( 12.7 mm) thick. Table II shows the
results of
the three point bend test demonstrating the load the sample will withstand.
Samples were then prepared for acoustical testing. Sample 1 a is '/o inch
{6.3 5 mm) molded AF glass fiber with the resin foamed throughout; 1 b is '/2
inch ( 12.7
-30-
CA 02274168 1999-06-07
WO 98/30375 PCT/(TS98/00446
mm). Sample 6a is a '/4 inch (6.35 mm) molded polyester fiber with the resin
foamed
throughout; sample 6b is '/2 inch ( 12.7 mm) thick. Table III gives the
results of the sound
absorption tests. Table I V shows the results of the three point bent test on
samples 1 and
6.
As the data in Table II demonstrate, samples 2a and 2b show the invention
produces a significantly greater structural strength than an unresinated fiber
mat.
Surprisingly, from Table IV it is shown that the samples of the invention
demonstrate an
even improved strength with respect to resin foamed glass fiber butts. In
Table III, the
results further show that in applications where sound absorption is important,
the samples
of the invention generally absorb sound as well as resin foamed glass fiber
butts.
Table I
Resin Formulation
Batch Requirements
Material Lbs. (kg) Gallons (L) Tank Height
Resin as in Example I 6450.0 (2925.7) 650 (2460.5) 84.5" (2146 mm) Down
Melamine (M:F, 1:2) 99.5 (45.1 ) 13 (49.2)
Sulfamic Acid (36.43% RESIN) 2285.2 (1036.5) 248 (938.8)
Ammonia (2.65% RESIN) 170.9 (77.5) 23 (87.1) 67.6" (1717 mm) Down
Silane (0.1% Material solids) 3.4 (1.5) 1557 Grams
Urea (2% Resin solids) 64.8 (29.4) 7 (26.5)
Premix Subtotal 9073.8 (4115.8) 941 (3562.1 )
Dawn (5.40% Material solids) 185.4 (84.1 ) 22 (83.3 ) 0.1970 Lb/gal premix
(23.606 kg/L)
OT-75 (0.789% Material solids) 27.1 ( 12.3 ) 3 ( 11.4) 0.0288 Lb/gal premix
(33.451 kg/L)
Subtotal 9286.3 (4212.2) 966 (3656.7)
Water 962.7 (436.7) 116 (439.1) 0.1228 Gal/gal premix
Total 10249.0 (4648.9) 1081 (4092.0)
-31-
CA 02274168 1999-06-07
WO 98130375 PCT/US98/00446
Material - Solids Lbs. (kg) Percent
Resin 3237.9 (1468.7) 94
Formaldehyde 63.7 (28.9) 2
Melamine 99.5 (45.1 ) 3
Urea 32.4 (14.7) 1
Total 3433.4 (1557.4) 100
Table II
Flexural 3 point bend (ASTM
D590 method I Procedure
B) series 9 program 77
Instron cross head speed
0.5 in ( 12.7 mm)/min
(high clutch)
Sample lA Load at Yield (lbs) ~k~l
Avg of 5 Samples 0.732 [0.332)
Std Dev 0.023 [0.010]
Sample 1B Load at Yield (lbs) Lkg1
Avg of 6 Samples 0.660 [0.299)
Std Dev 0.103 [0.047)
Samele 2A Load at Yield (lbs) fkal
Avg of 5 Samples 3.356 [1.522]
Std Dev 0.540 [0.245]
Sample 2B Load at Yield llbs) fk~l
Avg of 5 Samples 3.543 [1.607)
Std Dev 0.573 [0.260)
Table III
Impedance
Normal Incidence Sound
Absorption Test Results
on Headliner Candidate
Materials
Sample 1 A Avg. Sample 1 B Avg.
Frequency, Hz. of 2 Samples of 2 Samples
100 0.008 0.009
125 0.010 0.013
160 0.009 0.017
-32-
CA 02274168 1999-06-07
WO 98/30375 PCT/I1S98/00446
200 0.012 0.021
250 0.013 0.029
315 0.016 0.03 9
400 0.021 0.053
500 0.030 0.071
630 0.028 0.100
800 0.042 0.141
1000 0.062 0.184
1250 0.091 0.257
101600 0.133 0.326
Sample 6A Avg. Sample 6B Avg.
Frequency, Hz. of 2 Samples of 2 Samples
100 0.008 0.007
125 0.011 0.013
15160 0.010 0.014
200 0.014 0.022
250 0.016 0.028
31 S 0.018 0.03 8
400 0.020 0.053
20500 0.030 0.074
630 0.036 0.091
800 0.054 0.145
1000 0.076 0.204
1250 0.108 0.274
251600 0.154 0.367
Note the values given are percent of sound
presented as a absorption.
Table IV
ASTM D790 Procedure B Method I
Flexural Strength - Cross head 0.5"(12.7 mm)/min Chart 1"(25.4 mm)/min
30 sample sizes 4 inch x 12" (102 mm x 305 mm) with 10 inch (254 mm) span
-33-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
Sample: la -'/4" (6.35 mm) - std AF glass w / resin Load @ Yield (lbs) [kg]
Avg of 6 Samples 2.31 [1.048]
Std Dev 0.30 [0.136]
Sample: 1 b - '/2" ( 12.7 mm) - std AF glass w / resin Load @ Yield (lbs) [kg]
Avg of 6 Samples 1.54 [0.699]
Std Dev 0.17 [0.077]
Sample: 6a -'/4" (6.35 mm) - 15001 polyester w / resin Load @ Yield (Ibs) [kg]
Avg of 6 Samples 2.85 [1.293]
Std Dev 0.19 [0.086]
Sample: 6b -'/2" {12.7 mm) - 15001 polyester w / resin Load @ Yield (Ibs) [kg]
Avg of 6 Samples 1.72 [0.780]
Std Dev 0.11 [0.50]
Example IV
Table VI shows the resin formulation foamed throughout a polyester fiber
mat. Samples were prepared using the formulation and tested. Samples were
prepared at
three different thicknesses of polyester fiber mat, 5 mm, 11 mm and 17 mm. In
addition,
there are two different sample types of polyester mat for each thickness. One
set consists
of a polyester fiber mat containing 30% CelbondTM (binder fiber) whereas the
other set
contains 15% CelbondTM. Figure 10 gives the results of the effect of binder
content on
sound absorption. As the data demonstrates in general, polyester fiber mats
having lower
binder fiber (CelbondTM) concentrations provide greater sound absorption
capacity.
Accordingly, lower cost raw materials can be utilized in the invention without
any loss in
sound absorption capacity.
Sample No. Description
1 5 mm Polyester - 30% CelbondTM
2 11 mm Polyester - 30% CelbondTM
3 17 mm Polyester - 30% CelbondTM
4 5 mm Polyester - 15% CelbondTM
5 11 mm Polyester - 15% CelbondTM
6 17 mm Polyester - 15% CelbondTM
Figure 11 gives the results of the effect of molding temperature on sound
absorption test results for '/4 (6.3 5 mm) and 3/4" ( 19.05 mm) diameter
samples. Each
-34-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
sample was tested in large impedance tubes (for <6,000 Hz) and in small
impedance tubes
(>6,000 Hz). The data demonstrates that samples molded at the lower
temperature of
375° Fahrenheit ( 191 °C) outperform the samples molded at the
higher temperature of
450°F (232°C). These samples contained 15% CelbondTM binder
fiber.
Table V
tcesm ~ror components used
at <200F (<93C)
solids 43.3
formaldehyde 9.4
desired overall solids 41.0
DAP Mix lbs. (k~) Gallons (L)
water 434.0 (196.9)52.3 (198.0)
diamonuim phosphate 138.2 (62.7) --
Total 572.2 (259.5)67.0 (253.6)
Material lbs. (k~) Gallons (L)
urea (F:U, 1:1+8.47% excess) 3997.3 (1813.1)420.0 (1589.9)
A1100 silane (0.367% resin) 36.0 (16.3) 4.0 (15.1) 16316
grams
Resin (from above) 9801.0 (4445.7)990.0 (3747.6)
DAP (5.838% resin) 572.2 (259.5)67.0 (253.6)
Premix Subtotal 14406.5 (6534.7)1481.0 (5606.2)
ammonium sulfate/Calgon(3.135%307.3 (139.4)32.6 (123.4)
resin)
OT-75 (2.805% premix) 404.1 (183.3)45.2 (171.1)
yellow dye (BASF base acid)
(0.743% premix) 107.0 (48.5) 10.7 (40.5)
ammonia (2.57% premix) 370.4 (168.0)50.1 (189.6)
Subtotal 15595.3 (7073.9)1619.6 (6130.9)
water (8.228% premix) 1185.4 (537.7)142.3 (538.7)
Total 16780.6 (7611.6)1761.9 (6669.5)
Material Solids
Resin' 4241.9 ( 1924.1
)
Urea 1998.7 (906.6)
-35-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
Formaldehyde 921.3 (417.9)
Total 7161.5 (3248.4)
' A resole resin having 0.42% free phenol sold as RE 131 obtained from Owens
Corning.
Resin from Table V was prepared as follows. The DAP mixture was
dissolved in water heated to 125-150°F (52-66°C). This mixture
was then agitated
continuously and the temperature was lowered to 95°F (35°C) and
held there for 2 hours
while the catalyst slurry was added. The ammonium sulfate was added to the
premix; it
was added until the pH was from 8.95 to 9Ø
Table VI
Resin (for components used at >200°F [>93°C])
solids 53.1
formaldehyde at start 0.70 % left after 1 day 0.69
overall solids 34.0
Material lbs. (k~) Gallons (L) Tank Height
resin 7192.0 (3262.2)725 (2744.4)80.1" down
(2034.5 mm)
melamine (M:F, 1:2) 73.3 (33.2) 9 (34.1)
ammonia (2.65% resin) 190.6 (86.5) 26 (98.4)
sulfamic acid (36.79% 2645.9 (1200.2)288 (1090.2)88.0" down
resin)
(2235.2 mm)
silane (0.1 % material 3.8 ( 1.7) 0.745 grams
solids)
urea (2% resin solids) 73.7 (33.4) 8.0 (30.3)
Premix Subtotal 10179.4 (4617.3)1055.5 (3995.5)
Dawn (6% material solids)230.9 ( 104.7)27 ( 102.2) 0.2187 lb/gal
premix
(26.206 kg/L)
OT-75% (0.789% materialids) 30.4 3 (11.4) 0.0288 ib/gal
sol (13.8) premix
(3.451 kg/L)
Subtotal 10440.6 (4735.8)1086 (4111.0)
water (add to desired 876.5 (397.6)105 (397.5) 0.0997 gal/gal
solids) premix
Total 11317.1 (5133.4)1191 (4508.4)
-36-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
Material Solids Lbs~(k~) Percent
resin' 3687.3 (1672.5) 96
formaldehyde 50.3 (22.8) 1
melamine 76.3 (34.6) 2
urea 36.9 (16.7) 1
Totals 3847.8 (1745.3) 100
A resole resin having 2.5% free phenol sold as IB809B obtained from Borden
In preparing the resin of Table VI, the material components are
continuously agitated at 65°F (18°C). When the sulfamic acid is
added, the pH should be
less then 9Ø The ammonia is added when there are still 75 gallons (284 L) of
sulfamic
acid to be added. Prior to adding the silane, the temperature is raised to
120°F (49°C); it
is then lowered to 100°F (38°C) before adding the urea.
Another resin formulation is prepared for use in applications wherein lower
dust levels in molded products are desired, and those where greater toughness
is required.
This formulation uses the resin of Table VI with the following differences
given in Table
VII. The material is agitated and mixed at 100°F (38°C).
In addition, latex formations of new range of copolymers of vinyl acetate,
acrylic, ethylene-vinyl acetate, acrylic terpolymers, styrene acrylic
copolymers, urethane
acrylic copolymers and blends thereof are suitable substitutes to expand the
region of
lower emissions, faster cure times, low odor, low dust and better flexibility
in the molded
part. In another embodiment, Airflex 192 and Airflex 911, Flexbond 974 and
Airflex 124
provide excellent combination of above mentioned properties. These products
were
obtained from Air Products and Chemicals.
Table VII
Material % Solids
Resin from Table VI 34.0
BF Goodrich V-29 Latex
(Hystretch-elastomeric
latex emulsion) 48.2
Latex desired solids 35.0
Overall solids 36.0
-3 7-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
Material lbs. (k~) Gallons (L) Percent Premix
Resin Table VI 6600.0 (2993.7) 695.5 (2632.8) 0.69 617 gal.
(2335.6 L)
Latex (add to desired %) 2506.9 ( 1137.1 ) 290.1 ( 1098.1 ) 0.26
OT-75 (2% latex 24.2 (11.0) 2.7 (10.2) --
solids)
Subtotal 9131.0 (4141.8)988.4 (3741.5)
water (to desired 458.7 (208.1 55.1 (208.6) 0.05
solids) )
Total 9589.7 (4350.0)1043.5 (3950.1)
Material Solids Ibs. (k~)
Resin 2244.0 ( 1017.9)
Latex 1208.3 (548.1
)
3552.3 (1611.3)
Solution solids before
water 37.8 ( 17.1
)
Example V
Manufacture of Multi-Layer Laminate Ceilin~/WaII Tile
A heated hydraulic press mold was used to prepare an embossed/textured
2 ft. x 2 ft. (610 mm x 610 mm) ceiling panel. Mold release was sprayed in the
mold
which was then placed in a hydraulic heat press set to 385°F
(196°C). Both upper and
lower platens were used.
The resulting tile was tested for impedance and air flow. The tile was
tested alone and against a baseline piece of ductboard (3/4" [ 19.05 mm]
skived). The tile
was also tested for acoustical absorbance properties. The results may be seen
in Figure
13 and Table VIII. The results have allowed us to conclude that the acoustical
properties
can be tuned to fit the application and cost target. For example, NRC values
equal to 1.00
may be achieved by using a glass wool core, small diameter fiber, medium
density and
high rayls cover sheet fabric.
Example VI
A cold press was used to form a preheated polymeric batt with 8% binder
fiber. The batt was heated to 550°F (288°C). The heated batt was
placed in a cold 3D
contour tool, and formed under pressure. The resulting invention exhibited
excellent
acoustic performance, and better compared to similar thickness open-cell
urethane foam.
-3 8-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
Figure 15 shows the superior performance of the polymer fiber batt compared to
polyester
urethane open cell foam manufactured at two different densities.
Example VI I
A controlled air-flow zoned heating and cooling oven, such as
manufactured by Schott & Meissner or Fleissner, was used to manufacture an in-
line
polymeric batt reinforced with 50% glass fiber. The polymeric fiber batt,
which used
staple polyester fiber (3-6 Denier, 0.5-2" [ 12.7-51 mm] length), 12% bonding
sheath-core
fiber and 50% glass fiber manufactured by a rotary process was heated to
170°C and
passed through the oven with the air circulating through the batt, and
subsequently
quenched with ambient air at the exit of the hot air section of the oven. The
said product
was densified at thicknesses of 0.25" {6.35 mm), 0.5" ( 12.7 mm) and 6.0" {
152 mm). The
product exhibited excellent thermal and acoustic properties, and when handled
exhibited
no "itch" to the user, typical of 100% glass-based insulative products.
Table VIII
Specific
Airflow Airflow Airflow
Sample Thickness Density ResistanceResistanceResistivity
No. Inches (mm) PCF (kg/m') mks Raylsmks Rayls/m
Acoustic Ohms
New Molded
Ceiling
Tile (White)
lA 0.75 (19.05)7.037 (112.722)175815.81 1325.50 69580.05
1B 0.75 (19.05)6.746 (108.061)154792.19 1167.00 61259.84
1C 0.75 (19.05)6.785 {108.685)143398.32 1081.1 56675.66
Average 0.75 (19.05)6.86 (109.887) 158002.11 1191.20 62530.18
New Molded
Ceiling
Tile (Green)
2A 0.75 (19.05)7.485 {119.898)188032.06 1417.60 74414.70
2B 0.75 (19.05)7.876 (126.161)190074.73 1433.00 75223.10
2C 0.75 (19.05)7.111 (113.907)172194.71 1298.20 68146.98
Average 0.75 (19.05)7.49 (119.498) 183433.83 1382.93 72594.93
New Mold ed Ceiling
Tile (Duct
Board, Baseline)
3A 0.75 (19.05)5.642 (90.376) 75483.41 569.08 29872.97
3B 0.75 (19.05)5.459 (87.445) 98142.49 739.91 38840.42
-39-
CA 02274168 1999-06-07
WO 98/30375 PCT/US98/00446
3C 0.75 (I9.05) 6.120 (98.033) 112902.80 851.19 44681.89
Average 0.75 (19.05) 5.74 (91.946) 95509.57 720.06 37798.43
-40-
