Note: Descriptions are shown in the official language in which they were submitted.
05-05-20031RY 05 2003 10:43 FR CA 02444639 2003-10-17
TO 9011498923394465 P. ee US0216418
MULTIDENSITY I.N BPJ INSULATOR
Technical Field and Industrial
APPLTCABILlTY OF THE INVENTION
The present invention relates generally to a multilayer acoustical and thermal
linertinsulator which may be utilized to insulate an environment such as a
passenger
compartment of a vehicle from the beat and sound generated by mechanical
components of
that vehicle during its operation. Further uses include application in
insulating appliances
such as dishwashers and clothes dryers and providing sound and thermal
insulation for
to furnaces, air conditioning units and ductwork in buildings including homes,
offices and
industrial strucbzres.
BACKGROUND OF THE INVENTION
Acoustical insulation is well known in the art. Acoustical insulation
typically
relies upon both sound absorption, that is, the ability to absorb incident
sound waves, and
transmission loss, that is, the ability to reflect incident sound waves, in
order to provide
sound attenuation. One of the more prevalent uses of such insulation is in the
motorized
vehicle field where engine compartments, fire walls, fender wells, doors,
floor pans and
other components of the passenger compartment shell are commonly acoustically
insulated
to reduce engine and road noise for the benefit and comfort of passengers,
Mats of high temperature glass fibers have also been utilized, for example,
(a) on
the fire wall between the dashboard and engine compartment and (b) along the
floor pan of
the vehicle between the passenger compartment and the drive line and exhaust
system.
These materials provide heat insulation which makes it possible to maintain
cooler and
'25 more comfortable temperatures in the operator/passenger compartment
particularly during
the summer months. Additionally, these materials provide needed sound
insulation,
reducing or eliminating various mechanical sounds of the motor, drive train as
well as the
suspension and tires as the vehicle travels over the often rough and bumpy
surface of the
roadway.
Various methods of manufacturing or fabricating such acoustical and thermal
insulators are known in the art. Examples of these methods are- found, for
example, in
U.S. Patents 5,055,341 to Yamaji at al., 5,501,898 to Fortinger at al.,
3,652,377 to
Helmick and 5,591,289 to Souders et al.
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US0216418
In the Yamaji et al, patent, woven and/or non-woven fabrics are laminated to a
composite of fibers and thermal plastic resin. In the Fottinger et al. patent,
a rnultilayer,
multi-density composite is disclosed incorporating polyester fibers. The
fibers are
preheated in a furnace by metal plates above the melting point of The fibers.
The non-
3 woven fabric fiber layers are loaded into a molding tool and exposed to
molding pressure
for a dwell time sufficient to complete the molding process. The part is then
cooled below
the softening temperature of the fibers to set the composite in the final
molded shape.
In U.S. 3,652,377, Helmick teaches the formation of a two-layer fibrous pad
having
dissimilar densities in each of the layers. Specifically, it is taught to form
the pad by
iO pulling the two layers through a succession of compressing and heating
operations to
sequentially induce various desired dissimilar densities in the layers. In a
preferred
embodiment, a finished product embodies a one inch thick pad of a thermoset
resin
bonded intermeshed glass fiber having a first high density layer, adjacent one
major
surface, of about 3 to 3.5 pounds per cubic foot and a one-eighth inch
thickness and a
15 second low density layer, adjacent the first layer, Qf about t pound per
cubic foot and a
seven-eighths inch thickness.
In U.S. 5,591,2$9, Souders et al. teaches a fibrous headliner for a motor
vehicle
passenger compartment comprised of an internal section of nonwoven high loft
batting of
thermoplastic materials bound on either side by a batting material each having
a different
20 density. Formation of the headliner includes heating the batting having the
higher density
and coating it with a thermoset resin and sandwiching the entirety of the
headliner in an
appropriate molding structure for curing by heat.
Various additional examples of acoustical insulation commonly employed for
vehicle applications are found in U.S. Patents 5,298,694 to Thompson et al.,
5,624,726 to
25 Sanocki et al., 5,759,659 to Sanocki et al. and 5,961,904 to Swan et al.
The Thompson et al. patent discloses a non-woven acoustical insulation web of
thermoplastic fibers and a second layer, such as a scrim, non-woven fabric,
film or fail,
laminated thereto for water barrier protection.
The Sanochi et al. patents disclose an acoustical insulation blanket in the
form of a
30 composite featuring an insulation layer of fibrous insulation, foam
insulation or a
combination thereof and a high temperature-resistant layer of ceramic paper,
woven
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US0216418
ceramic fibers, woven fiberglass fibers, ceramic non-woven scrims or
fiberglass non-
wovert scrims encased in a heat sealable thermoplastic polyolefin which
functions as a
moisture barrier.
The Swan et al patent discloses a non-woven acoustical insulation web of
thermally stabilizing melt-blown polypropylene microfibers which may also
contain staple
fibers such as crimped bulking fibers and/or binder fibers. The acoustical
insulation web
is formed as a laminate with a water barrier layer of planer thermoplastic
polyolefin film
such as polyethylene, polypropylene and ethylene propylene copolymer films.
In other instances, manufacturers have utilized one or more layers of ethylene
vinyl
acetate ancVor polyvinyl chloride to provide the desired moisture barrier. The
added water
barrier layer(s) often add significant weight to the insulation product. This
is a very
significant disadvantage to vehicle manufacturers seeking to reduce overall
vehicle weight
and increase fuel economy.
In many acoustical insulation applications and particularly.those relating to
motorized vehicles, water barrier protection is a critical concern. As
demonstrated by
these prior art patents, it has generally been found necessary to add water
barrier protection
to the acoustical insulation material since this material is otherwise too
pervious
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CA 02444639 2009-09-23
to water and allows water intrusion. Toward this end it has been common
practice to
provide laminate constructions which are effective for the intended purpose
but suffer
several shortcomings. Specifically, as a result of handling and manipulation
during
installation and/or deleterious and degradating effects of various
environmental factors over
time, delamination commonly occurs. This delamination typically reduces the
effectiveness
of the water barrier thereby potentially allowing for unwanted water intrusion
by wicking
and capillary action. A need is therefore identified for an improved
insulation providing
enhanced acoustical and thermal insulating properties and dependable water
barrier
protection over an extended service life all in a light weight product
suitable for use even in
compact and subcompact vehicles.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is provided a
liner/insulator, comprising: a pad of fibrous material having a lofty,
acoustically insulating
portion having a density of between 8.0-80.0 kg/m3, a relatively higher
density skin formed
of heat-seared polymer fibers along at least one face thereof, the skin having
a thickness of
between 0.25-10.0 mm and a density of between 32.0-1600.0 kg/m3, and a crimped
margin
having a thickness of 0.5-3.0 mm.
In accordance with another aspect of the present invention, there is provided
an
acoustical liner with integral water barrier, comprising a pad of fibrous
material having a
lofty, acoustically insulating portion having a density of between 8.0-80.0
kg/m3, a
relatively higher density, water-barrier skin along at least one face thereof,
the skin having a
thickness of between 0.25-7.5 mm and a density of between 32.0-1600.0 kg/m3,
and a
crimped margin having a thickness of 0.5-3.0 mm.
In accordance with another aspect of the present invention, there is provided
a
method of insulating a door including an exterior body panel and an interior
fascia panel
defining a cavity there between, the method comprising placing a pad of
fibrous material in
the cavity between the exterior body panel and the interior fascia panel, the
pad of fibrous
material having a lofty, acoustically insulating portion having a density
between 8.0-80.0
kg/m3, a relatively higher density skin formed of heat-seared polymer fibers
along at least
one face thereof, the skin having a thickness between 0.25-7.5 mm and a
density of between
32.0-1600.0 kg/m3, and crimped margin having a thickness of 0.5-3.0 mm.
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CA 02444639 2009-09-23
In accordance with another aspect of the present invention, there is provided
a door
for a vehicle, comprising: an exterior body panel; an interior fascia panel
connected to the
exterior body panel and defining a cavity between the exterior body panel and
the interior
fascia panel; and a pad of fibrous material having a lofty, acoustically
insulating portion
having a density of between 8.0-80.0 kg/m3, a relatively higher density skin
formed of heat-
seared polymer fibers along at least one face thereof, the skin having a
thickness between
0.25-7.5 mm and a density of between 32.0-1600.0 kg/m3, and a crimped margin
having a
thickness of 0.5-3.0 mm. The pad of fibrous material may be a nonlaminate. The
pad of
fibrous material may include the relatively higher density skin along a second
face thereof.
A first facing layer may be carried on a first face of the pad of fibrous
material. A second
facing layer may be carried on a second face of the pad of fibrous material.
The first and
second facing layers may be formed from a material selected from polyester,
rayon, and
metallic foil.
In accordance with another aspect of the present invention, there is provided
a liner
for an airstream conduit or housing, comprising: a pad of fibrous material
having a lofty,
acoustically insulating portion having a density of between 8.0-80.0 kg/m3 and
a relatively
higher density skin formed of heat-seared polymer fibers along at least one
face thereof, the
skin having a thickness of between 0.25-10.0 mm and a density of between 32.0-
1600.0
kg/m3, and a crimped margin having a thickness of 0.5-3.0mm. The fibrous
material may be
selected from (a) thermoplastic polymer staple fibers and thermoplastic
bicomponent fibers,
(b) glass staple fibers and thermoplastic bicomponent fibers and (c)
combinations of (a) and
(b). The fibrous material may be selected from polyester, polyethylene,
polypropylene,
polyethylene terephthalate, glass fibers, and natural fibers. The pad of
fibrous material may
be a nonlaminate.
An improved acoustical and thermal liner/insulator of enhanced performance
characteristics is disclosed. In an exemplary embodiment, the liner/insulator
includes a pad
of fibrous material having a lofty, acoustically insulating portion having a
density of
between substantially 8.0-80.0 kg/m3.
The liner/insulator also includes a relatively higher density skin along at
least one
face thereof. The skin has a thickness of between substantially 0.25-10.0 mm
and a density
of between substantially 32.0-1600.0 kg/m3.
The fibrous material of the liner/insulator is selected from a group
consisting of (a)
thermoplastic polymer staple fibers and thermoplastic bicomponent fibers, (b)
glass staple
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CA 02444639 2009-09-23
fibers and thermoplastic bicomponent fibers and (c) a combination of (a) and
(b). The
fibrous material may be polyester, polyethylene, polypropylene, polyethylene
terephthalate,
glass fibers, natural fibers and any mixtures thereof.
The pad is a nonlaminate and, accordingly, the potential for the relatively
higher
density skin to delaminate from the remainder of the pad is eliminated. In one
embodiment
of the invention, the pad includes a higher density skin along a second face
thereof as well.
In yet another embodiment, the liner/insulator includes a first facing layer
along a
first face thereof. In still another embodiment, the liner/insulator includes
a second facing
along a second face thereof. The first and second facings may be constructed
from polyester,
rayon, metallic foil and any mixtures thereof.
An acoustical liner with integral water barrier is also disclosed. The
acoustical liner
comprises a pad of fibrous material having a lofty, acoustically insulating
portion having a
density of between substantially 8.0-80.0 kg/m3 and a relatively higher
density, water-
barrier skin along at least one face thereof The skin has a thickness of
between substantially
0.254-7.5 mm and a density between approximately 32.0-1600.0 kg/m3. The pad is
formed
from fibrous materials selected from a group consisting of polyester,
polyethylene,
polypropylene, polyethylene terephthalate, glass fibers, natural fibers and
any mixtures
thereof. The pad and heat- seared, water-barrier skin are integral and,
accordingly, the
acoustical liner is a non-laminate. As such, it avoids any tendency to
delaminate as is
characteristic of the water barrier layers laminated to acoustical insulation
materials
commonly employed in the prior art.
The acoustical liner with integral water barrier may further include a crimped
margin around at least a portion of the periphery of the pad where the crimped
margin has a
thickness of at least about 0.5-3.0 mm. This margin provides additional
strength and a
suitable location to mount the liner to, for example, a door panel or other
structural
component of a vehicle requiring acoustical insulation by means of mechanical
fasteners of
a nature known in the art.
Of course, the pad of the acoustical liner with integral water barrier may
also include
two heat-seared skins. Additionally, the pad may include one or more facing
layers
composed of polyester, rayon, metallic foil and any mixtures thereof.
A method of insulating a door including an exterior body panel and an interior
fascia
panel defining a cavity therebetween is disclosed. The method comprises the
placing of a
pad of fibrous material in the cavity between the exterior body panel and the
interior fascia
5
CA 02444639 2009-09-23
panel. The pad has a lofty, acoustically insulating portion having a density
of substantially
8.0-80.0 kg/m3 and a relatively higher density skin along at least one face
thereof having a
thickness of between substantially 0.25-7.5 mm.
A door for a vehicle is disclosed. The door includes an exterior body panel,
an
interior fascia panel connected to the exterior body panel and defining a
cavity therebetween
and a pad of fibrous material having a lofty, acoustically insulating portion
having a density
of substantially 8.0-80.0 kg/m3 and a relatively higher density, water-barrier
skin along at
least one face thereof.
That skin has a thickness of between substantially 0.25-7.5 mm. That pad is
formed
from fibrous materials selected from a group consisting of polyester,
polyethylene,
polypropylene, polyethylene terephthalate, glass fibers, natural fibers and
any mixtures
thereof. The pad is a nonlaminate and may also include a crimped margin around
at least a
portion of the periphery of the pad where the crimped margin has a thickness
of at least
about 0.5-3.0 mm. As noted above, this crimped margin provides a convenient
fastening
point for securing the acoustical liner to the exterior and/or interior panels
of the door or
other component to which the acoustical liner is to be secured. The pad of the
acoustical
liner may also include two heat-seared skins.
A liner for an airstream conduit, such as a heating and air conditioning duct,
or a
housing such as for a furnace or air conditioning unit, is disclosed. That
liner comprises a
pad of fibrous material having a lofty, acoustically insulating portion having
a density of
between about 8.0-80.0 kg/m3. That liner also includes a relatively higher
density skin along
at least one face thereof. The skin has a thickness of between about 0.25-
10.00 mm and a
density of between about 32.0-1600.0 kg/m3. The liner may be formed from
polyester,
polyethylene, polypropylene, polyethylene terephthalate, glass fibers, natural
fibers and any
mixtures thereof. The liner may also include a second skin and, if desired for
any particular
application, one or more facings. The facings may be constructed from
polyester, rayon,
metallic foil and any mixtures thereof.
Still other features and benefits of the present invention will become
apparent to
those skilled in this art from the following description wherein there is
shown and described
preferred embodiments of this invention, simply by way of illustration of
several of the
modes best suited to carry out the invention. As it will be realized, the
invention is capable
of other different embodiments and its several details are capable of
modification in various,
5a
CA 02444639 2009-09-23
obvious aspects all without departing from the invention. Accordingly, the
drawings and
descriptions will be regarded as illustrative in nature and not as
restrictive.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying drawing incorporated in and forming a part of the
specification,
illustrates several aspects of the present invention and together with the
description serves
to explain the principles of the invention. In the drawing:
Figure 1 is an end elevational view of a liner/insulator of the present
invention
including a relatively higher density skin along one face;
Figure 2 is an end elevational view of another embodiment of the invention
5b
CA 02444639 2003-10-16
WO 02/098643 PCT/US02/16418
including two relatively higher density skins along two opposing faces
thereof;
Figure 3 is an end elevational view of yet another embodiment of the present
invention including one relatively higher density skin along one face and a
facing along
the opposite face thereof;
Figure 4 is an end elevational view illustrating still another embodiment of
the
invention with a facing covering a relatively higher density skin along one
face and a
second facing covering the opposite face;
Figure 5 is a perspective view of an acoustical liner with an integral water
barrier;
Figure 6 is a detailed cross sectional view of the acoustical liner shown in
Figure 5;
Figure 7 is a detailed cross-sectional view of an alternative embodiment
showing
an acoustical liner with two, opposed relatively higher density skins; and
Figure 8 is an exploded perspective view of a vehicle door constructed in
accordance with the teachings of the present invention.
Reference will now be made in detail to the present preferred embodiments of
the
invention, examples of which are illustrated in the accompanying drawing.
DETAILED DESCRIPTION AND PREFERRED
EMBODIMENTS OF THE INVENTION
Reference is now made to Figure 1 which illustrates a first embodiment of the
liner/insulator of the present invention generally designated by reference
numeral 10. The
liner/insulator 10 includes a pad 12 of fibrous material. The fibrous material
may take the
form of (a) thermoplastic polymer staple fibers and thermoplastic bicomponent
fibers, (b)
glass staple fibers and thermoplastic bicomponent fibers and (c) a combination
of (a) and
(b). The thermoplastic staple fibers and bicomponent fibers may be selected
from a group
of materials including but not limited to polyester, polyethylene,
polypropylene,
polyethylene terephthalate and any mixtures thereof. The glass fibers may
include E-glass,
S-glass or basalt fibers. Natural fibers (for example, hemp, kenaf) may also
be included.
The pad 12 includes a lofty, acoustically insulating portion 14 having a
density of
between substantially 8.0 - 80.0 kg/m3 and a relatively higher density skin 16
along one
face thereof. The skin 16 has a thickness of between substantially 0.25 - 10.0
mm and a
density of between substantially 32.0 - 1600.0 kg/m3. The density of the skin
16 maybe
substantially constant throughout its thickness or it may vary gradually lower
from a
maximum density along the outer face thereof to a density just above that of
the insulating
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CA 02444639 2003-10-16
WO 02/098643 PCT/US02/16418
portion 14 along the inner portion thereof. Where the density of the skin 16
varies, the
average density for the skin falls within the indicated range.
In accordance with an important aspect of the present invention, the pad 12
including both the relatively lower density insulating portion 14 and the
relatively higher
density skin 16 is formed from a single, unitary sheet of fibrous starting
material. As such,
the pad 12 is a nonlaminate and, accordingly, there is no tendency for the
skin 16 to
delaminate from the insulating portion 14 under any environmental conditions
to which
the liner/insulator is likely to be subjected. The skin 16 provides the pad 12
with added
mechanical strength and rigidity which aids in handling the liner/insulatorlO
during
installation on an apparatus or component, such as a vehicle body component,
furnace or
air conditioning unit housing or ductwork being insulated.
For many applications, the skin 16 functions to maintain the integrity and
acoustical and thermal insulating performance of the liner/insulator 10 over a
long service
life. More specifically, the skin 16 provides extra mechanical support.
Further, the
increased density of the skin 16 closes the pores of the material making it
impervious to
many potential environmental contaminants which might otherwise degrade the
performance of the liner/insulator over time. Thus, it should be appreciated
that the skin
16 effectively functions to protect the insulating portion 14 in much the same
manner as a
laminated facing material does in prior art liner/insulator designs. Such
prior art facing
layers inherently have the potential to delaminate and fail. This is a
significant drawback
when one considers the harsh operating environments to which such liners and
insulators
are often exposed. Advantageously, the present invention eliminates this risk
of
delamination which potentially could otherwise lead to liner/insulator
failure.
As illustrated in Figure 2, another embodiment of the liner/insulator 10
includes
the pad 12 with the lofty, acoustically insulating portion 14 and the skin 16
as described
above for the Figure 1 embodiment. In addition, the Figure 2 embodiment
includes a
second skin 18 along the opposing face of the pad 12. The second skin 18 may
have the
same physical attributes described above for the first skin 16. The two skins
16, 18 may,
however, vary from each other in thickness and/or density within the indicated
ranges.
As illustrated in Figure 3, an additional embodiment of the liner/insulator 10
includes the pad 12 with the lofty, acoustically insulating portion 14 and the
skin 16 as
described above with respect to the Figure 1 embodiment. In this embodiment,
the face 20
of the pad opposite the skin 16 carries a facing layer 22. The facing layer 22
may be made
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WO 02/098643 PCT/US02/16418
from polyester, rayon, metallic foil and any mixtures thereof. Such a facing
layer 22 may
be employed for an aesthetic, decorative purpose or for a utilitarian purpose
such as heat
reflection and dissipation.
Still another possible embodiment of the present invention is illustrated in
Figure
4. The liner/insulator 10 of Figure 4 includes a pad 12, a lofty, insulating
portion 14 and a
skin 16 just as described above with respect to the Figure 1 embodiment. In
addition, the
liner/insulator 10 includes a first facing layer 24 covering the skin 16 and a
second facing
layer 26 covering the opposite face 28 of the pad 12. The two facing layers
may be made
from polyester, rayon, metallic foil and any mixtures thereof. Of course, a
multilayer
facing material may also be used.
In applications requiring superior heat insulative characteristics, the facing
layer
22, 24 and/or 26 may be formed from a heat reflective material such as a
metallic foil (for
example, aluminum or other heat reflective metal). Where a metallic foil is
used foil
thickness is generally in the range of 0.25 - 7.5 mm. The thickness selected
is based upon
the temperature, durability and structural requirements of the particular
product
application.
The facing layer 22, 24 and/or 26 may be reinforced or non-reinforced.
Reinforcements are included to add durability and structural integrity.
Reinforcements
may take the form of fibrous scrims, fibrous mats or fibrous webs. For many
applications,
the reinforcement is made from a relatively strong fiber such as fiberglass.
Typically,
glass fiber threads are arranged in a criss-cross pattern. The number of
threads per inch
can be adjusted to provide the desired product properties. The fiber
reinforcement strands
are regularly spaced across the web and cross-web directions of the foil.
Typically,
spacing patterns include but are not limited to 4X4 (four strands per inch in
both
directions), 3X3, 2X2, 4X2 and 3X2. Typical patterns are rectangular and
diamond. The
strands may be materials other than glass which provide the desired properties
(for
example, polyester).
Alternative reinforcement materials for the facing layer 22, 24 and/or 26
include
but are not limited to glass mats, polymer mats and blended mats. The
reinforcement may
be preattached to the metallic foil. Alternatively loose laid reinforcement
may be utilized.
In most applications, the foil layer reinforcement provides improved tear
resistance,
strength and/or acoustical insulating properties. However, in many
applications, it should
be appreciated that no reinforcement is necessary.
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The facing layer 22, 24 and/or 26 (reinforced or non-reinforced) is attached
to the
polymer based pad 12 by means of a heat activated adhesive. The adhesive
utilized may
be a thermoplastic sheet or thermoplastic web material that tends to melt and
flow at
temperatures between 200'F-350'E Adhesives of this type are desirable because
they can
be activated during the molding phase of production. Besides thermoplastic
sheets and
webs, adhesives such as hot melts, latex and various heat activated resins may
be utilized.
The adhesive may be a separate layer as illustrated or the adhesive may
already be
attached to the facing layer 22, 24 and/or 26 in a dot matrix (that is,
uniform) or sintered
(that is, random) pattern.
An acoustical liner 10 with integral water barrier, such as shown in Figure 5,
is
just one possible product of the present invention. The acoustical liner 10
includes a pad
12 of fibrous material. The pad 12 is constructed from material characterized
by the
ability to absorb incident sound waves and the ability to reflect incident
sound waves so
that the material provides excellent sound attenuation. Accordingly, the pad
12 maybe
constructed from a group of materials including polyester, polyethylene,
polypropylene,
polyethylene terephthalate, glass fibers, natural fibers and any mixtures
thereof.
As shown in Figure 6, the pad 12 includes a lofty, acoustically insulating
portion
14 having a density of between about 8.0 - 80.0 kg/m3 and a heat-seared skin
16 of
increased density that resists water permeation and functions as a water
barrier. The face
16 has a thickness of between substantially 0.25 - 7.5 mm and preferably has a
density on
the order of approximately 32.0 - 1600.0 kg/m3.
The insulating portion 14 and skin 16 are integrally formed during the
manufacturing process and as such the liner 10 is a nonlaminate. Since the
liner 10 does
not comprise layers held together by adhesive it does not suffer from any
tendency to
delaminate and, therefore, it provides reliable and dependable water-barrier
protection and
acoustically insulating properties over a long service life.
A crimped margin 30 is provided around at least a portion of the outer
periphery of
the pad 12. The crimped margin 30 may have a thickness of about 0.5 - 3.0 mm.
The
material in the crimped margin 30 is compressed so as to be characterized by a
relatively
higher density. Accordingly, the crimped margin 30 is stronger and, therefore,
better
suited to hold mechanical fasteners (not shown) such as screws and plastic
snap rivets of a
type well known in the art utilized to secure insulation sheeting to vehicle
panels or the
like.
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As shown, the liner 10 may also include various cutout openings 32, 34 in the
body
thereof to accommodate door operating structures such as door latch handle and
window
operating mechanisms. A crimped margin 36 similar to the crimped margin 30 may
be
provided around one or more of these openings and has been illustrated in the
drawing
Figure 5 around the opening 34.
In an alternative embodiment of the liner 10 shown in Figure 7, a second, heat-
seared skin 18 is provided opposite the first, heat-seared skin 16. While not
explicitly
shown, it should be appreciated that the edges of the liner 10 may also be
heat-seared in
order to enhance water-barrier protection in applications where water-barrier
protection is
of critical importance.
The construction of a door 38 of a vehicle is shown in Figure 8. The door 38
generally comprises an exterior body panel 40 including a window opening 42
and an
interior fascia panel 44. A cavity 46 is defined between the two panels 40, 44
when they
are secured together. A liner 10 of the type described above and shown in
detail in
Figures 5, 6 or 7 including a pad 12 having a lofty, acoustically insulating
portion 14 and
at least one heat-seared, water-barrier skin 16 is placed in the cavity 46.
More
specifically, the liner 10 may be secured by mechanical fasteners or other
means of a type
known in the art to either the exterior panel 40 or the interior panel 46 of
the door 38.
A number of different techniques may be utilized to manufacture the
liner/insulator
10 of the present invention. The liner/ insulator 10 may be prepared by
differential
heating and uniform compression. As a specific example, the liner 10 shown in
Figure 6
is prepared by heating one side of the blanket or pad 12 of insulation
material, that is, the
side to include the heat-seared, water-barrier skin 16, while the other side
remains
relatively cool. A pressure is then applied for sufficient time to allow the
polymer binding
fiber to soften near the hot surface but not near the cold surface. When this
occurs under
compression, the hot side is reshaped into a higher density layer or skin. The
cool side of
the polymer binding fiber does not soften and, therefore, when the pressure is
removed, it
retains most of its original thickness and density characteristics. This
technique may be
performed in a standard molding press where one platen runs hot and the other
runs cool.
In an alternative technique, two polymer binding fibers having significantly
different softening points are utilized. In one approach, two separate blanket
layers are
produced each utilizing a different softening point polymer fiber. The two
layers are
brought together in a molding operation utilizing differential heating and
compressed to a
CA 02444639 2009-09-23
given gap width for a given length of time and at a given temperature
differential. The
blanket layer with the lower softening point polymer binding fiber is placed
next to the hot
platen and the higher softening blanket layer is placed next to the cool
platen. When
compression occurs, a higher density layer or skin 16 is formed from the lower
softening
point blanket layer while the higher temperature layer is unaffected and
retains its original
density. The layers are otherwise fused so as to have an integral
construction.
In an alternative approach, the blanket layer with the higher melting point
polymer
fiber is preformed and then that layer is fed back through the forming oven
during formation
of the lower melting point blanket. Since the oven is running at a temperature
cooler than
that required to activate the higher softening polymer binding fiber, it
undergoes
compression in the oven but retains its original thickness and density upon
exiting the oven.
The lower softening point material also undergoes compression and since the
oven is at a
temperature sufficient to activate its polymer binding fiber, it is squeezed
down to a high
density layer, and the two layers are fused together as one.
Additional information respecting the manufacturing of the liners/insulators
10 of
the present invention may be gleaned from a review of U. S. Patent No.
6,572,723, issued
June 3, 2003.
The foregoing description of preferred embodiments of the invention has been
presented for purposes of illustration and description. It is not intended to
be exhaustive or
to limit the invention to the precise form disclosed. Obvious modifications or
variations are
possible in light of the above teachings. For example, the liner/insulator 10
could include
two skins, both covered by a facing layer. The liner/insulator 10 could
include only one skin
covered by a facing layer. The liner/insulator 10 may include a skin along one
or more of its
edges.
The embodiments were chosen and described to provide the best illustration of
the
principles of the invention and its practical application to thereby enable
one of ordinary
skill in the art to utilize the invention in various embodiments and with
various
modifications as are suited to the particular use contemplated. All such
modifications and
variations are within the scope of the invention as determined by the appended
claims when
interpreted in accordance with the breadth to which they are fairly, legally
and equitably
entitled.
11
