Note: Descriptions are shown in the official language in which they were submitted.
1075~172
~ASTIC CO.~POSITI~N AND COMPOSITE
STRUCTURAL PANELS F~RMED THER~FR~M
Cross-Reference to a Related Application
.
This is a division of application Serial No.
203,099, filed June 21, 1974.
Background of the Invention
The present invention relates generally to
structural or huilding components and in P~rticular
to mastic compositions, methods of formin~ same, and
composite structural panels utilizing mastic composi-
tions as well as methods and apparatus for forming
such panels.
In the past, various mastic compositions,
methods of forming them, and composite structural panels
utilizing mastic compositions as well as methods and
apparatus for forming composite structural panels have
been disclosed, but while each had certain advantageous
features, none contained all or even most of the fea-
tures desirable for forming or use of the composite
panels as a structural or building component.
U.S. patent 3,021,291 discloses mixing expand-
able polystyrene beads with a cementitious slurry, usina
a gas to form a cellular material with voids therein,
and, after setting or curing, heating to expand the
beads which are intended to fill voids. U.S. patents
3,630,820 and 3,697,366 each disclose that closed-cell
expanded polystyrene beads, when mixed in a cementitious
slurry, rise or float to the top of the slurry so as to
make it impossible to attain a homogeneous mixture.
In these disclosures, expanded polystyrene beads are
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1~)75~7Z
shredded to open the cells of the normally closed-cell
beads thereby to permit them to absorb slurry into their
shredded open cells which overcomes the flotation prob-
lem and ensures a homogeneous mix of shredded open-cell
beads with the slurry. U.S. patent 3,598,672 describes
mixing expanded polystyrene beads with an epoxy resin,
admixing glass fibers which adhere to the surfaces of the
beads, subjecting this mixture to pressure to effect
setting thereof and then separating the beads coated
with glas~ fibers for use in forming other products.
U.S. patent 2,633,439 discloses a composite
structural p~nel with a core of spiral ~od shavir.gs
and gypsum plaster facing layers or walls with the edges
of the shavings embedded in the opposite wall surfaces,
but each of the spiral wood shavings has a central
aperture to provide free passage of air between cells
and to the exterior of the panel. U.S. patent
2,892,339 shows a honeycomb core structural panel
formed in its entirety of molded gypsum material. One
face and the honeycomb structure are integrally formed,
then cured, and then pressed into the other face to
form the panel. One notch is provided in one wall edge
of each individual honeycomb cell to permit the circula-
tion of air throughout the core of the assembled honey-
comb structure, in which wire mesh and/or fibers may be
~o7s~72
used for reinforcement. U.S. patent 3,249,659 discloses
the application of a thin layer of foam-forming polyure-
thane resin to opposite surfaces of two webs of paper
facing material which are brought into contact with
opposite faces of a honeycomb core and the assembly
then heated to effect foaming of the resin. Holes are
provided in the honeycomb walls interconnecting each
individual honeycomb cell to permit air circulation
throughout the entire honeycomb core.
Summary of the Invention
Among the several objects of the present in-
vention may be noted the provision of composite struc-
tural panels that are lighter in weight and yet have
excellent structural strength, thermal insulating and
sound-deadening properties. Other objects and features
will be in part apparent and in part pointed out here-
inafter.
,~ ~
~ -4-
:~()7~7Z
Briefly, a composite structural panel of this
lnvention comprises a cellular honeycomb core of ther-
mally insulative material having opposite faces and
walls between each cell, the cells extending from one
face thereof to the other, the walls having opposite
edges constituting the opposite faces of the core, and
a layer of an imporous heat and sound retardant compo-
sition on each of the opposite faces and penetrating
into each cell. The composition comprises a hardened
homogeneous mixture of low density closed cell expanded
synthetic resin beads and a slurry prepared from cal-
cined gypsum and water. Facing material is provided
on the outside surface of each layer. The walls have
notches in the opposite edges defining openings between
each cell and adjacent the opposite faces predetermining
the penetration of the layers into the cells to extend
into each cell just beyond the notches thereby closing
the openings and trapping air in the cells to limit the
penetration of the edges into the layers, controlling
the thickness of the layers between the facing material
and the opposite core faces and providing additional
thermal and sound insulation. The layers further include
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107~:~72
reinforcing fibers which extend between adjacent cells
and through the notches thereby to provide strength-
ening ties with the portions of the layers in adjacent
cells and between adjacent cells.
Brief Description of the Drawings
Fig. 1 is a flow diagram illustrating a method
of this invention for forming a mastic composition of
this invention;
Fig. 2 is a schematic illustration of appa-
ratus of this invention for forming composite structuralpanels utilizing the mastic composition of this invention;
Fig. 3 is a fragmentary plan view showing a
honeycomb expander used in the apparatus of Fig. 2;
Fig. 4 is a fragmentary perspective view of
a composite structural panel of this invention;
Fig. 5 is a section on line 5--5 of Fig. 4;
Fig. 6 is a partial plan view schematically
showing additional apparatus of this invention utilized
with the apparatus of Fig. 2 for spraying glass fibers
on a mastic composition layer and for raking glass fibers
into the layer;
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Fig. 7 is a side elevation of Fig. 6;
Fig. 8 is a fragmentary section of a com-
posite structural panel of this invention wherein glass
fibers are raked into the mastic composition layer;
Fig. 9 is a fragmentary section of a com-
posite structural panel of~this invention showing glass
fibers initially mixed with the mastic composition;
- Fig. 10 is a side elevation schematically
illustrating the apparatus of Fig. 2 modified to embed
open mesh reinforcing material in the mastic composi-
tion layers of the structural panels being fabricated;
Fig. 11 is a fragmentary perspective view of
the Fig. 10 apparatus;
Fig. 12 is a fragmentary perspective view of
a composite structural panel of this invention having
reinforcing material embedded in hardened mastic composi-
tion layers thereof;
Fig. 13 is a section on line 13--13 of Fig. 12;
Fig, 14 is a side elevation of the apparatus
of Fig. 2 modified to insert open mesh reinforcing strips
between lengths of honeycomb core material and to em-
bed the edges of these strips in the mastic composition
layers;
Fig. 15 is a plan of Fig. 14;
1(37~72
Fig. 16 is an enlarged fragmentary view taken
from Fig. 15, showing the insertion of o?en mesh rein-
forcing strips between side-by-side lengths of honey-
comb material;
Fig. 17 is a fragmentary perspective view
showing a composite structural panel of this invention
with an open mesh reinforcing strip inter2osed between
honeycomb core lengths and with the opposite edges there- ;
of embedded in the hardened mastic composition layers;
Fig. 18 is a section on line 18--18 of Fig.
17i and
Fi~. 19 is a fragmontary sectional ~iew showing
an erection tie receiving groove provided in opposite
sides of a composite structural panel of this invention.
Corresponding reference characters indicate
corresponding parts throughout the several views of the
drawings.
Descri tion of the Preferred Embodiment
p
Referring now to Fig. l, there is shown a
flow diagram illustrating a method of forming a mastic
composition of this invention. In general, a slurry is
prepared from calcined gypsum and water, and a volume of
low-density expanded closed-cell synthetic resin beads, such
as expanded polystyrene beads, which have an interstitial
volume not substantially more than the volume of the slurry,
is admixed to the slurry to form the mastic composition.
Reinforcing fibers such as glass fibers, natural or
synthetic fibers, metal chips, comminuted metal wire
or the like, may also be admixed with the slurry and
~079~72
expanded beads replacing a portion of the expanded beads
generally for the purpose of reinforcing the mastic com-
position and enhancing the adhering and flowability
characteristics thereof, and the strength properties of
the composition after setting. Alternately, reinforcing
fibers may be added to the mastic composition.
This mastic composition has physical charac-
teristics uniquely suitable for the manufacture of com-
posite structural panels, although it also has other
uses. For instance, inclusion of the expanded synthetic
resin beads provides a relatively lightweight mastic
composition, and the manner and quantities of mix pro-
vides a mastic composition which is readily workable
and adapted for use in continuous manufacturing processes.
In its mastic stage, the composition has the physical
characteristics of being a substantially imporous and
homogeneous mixture which is extrudable, easily spread
or applied to a surface, and is self-adhering as a
relatively thick layer on an inverted smooth surface yet
separable therefrom as an integral layer. When the mastic
composition sets up or dries, it provides a hard, strong,
dimensionally stable, heat- and sound-resistant material
which when utilized in the fabrication of composite
structural panels, as described hereinafter, is capable
of withstanding surprisingly high stresses in tension,
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compression and shear while providing a surface
extremely accurate in flatness tolerance which is
architecturally desirable for design, structural ar.d
construction purposes. Mastic compositions which
exhibit these desirable physical characteristics are
attainable within certain weight and volume ranges of
the slurry, expanded synthetic resin beads and, if
desired, glass fibers. It has been found that these
ranges are important in the forming of mastic composi-
tions having the desirable physical characteristics andqualities previously mentioned. If the volume of the
sl~rry and expa~ec` synthctic resin bea~_ are subst~n-
tially outside of these ranges, the ~astic com?osition
is either too thick to mix, work or apply onto a sur-
face or else so thin or runny that the expanded beads
float on the slurry and a heterogeneous unusable mix-
ture results.
In the method of forming the mastic composi-
tion, a slurry is prepared by mixing bet~een about 55
to about 65~ by weight of calcined gypsum (plaster of
Paris) with between about 35~ to about 45~ by weight
of water. To the resulting thick slurry is admixed a
predetermined volume of low-density expanded closed-
cell synthetic resin beads, such as expanded polystyrene
beads, which, for example, have a typical size range of
1/16" to about 1/8". Thus the composition is free of
components such as surface active or wetting agents.
The predetermin~d volume of expanded beads admixed with
the slurry is that which has an interstitial volume not
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substantially more than the volume of the slurry and
wherein the volume of the slurry is not more than about
25% in excess of the interstitial volume of the expanded
beads. The interstitial volume is the volume of the
unoccupied space remaining in any given amount of the
dry beads at atmospheric pressures. By way of illustra-
tion, an example of a desirable mastic composition within
the above-mentioned ranges and based on volume of expanded
beads to slurry is about 60% by volume of beads to about 40%
by volume of slurry. Also by way of illustration, an example
of a desirable mixture of the mastic composition within the
above-mentioned ranges is obtained by admixing about 2
parts by weight of expanded beads in a slurry prepared
from about 25 parts by weight of calcined gypsum and about
17 parts by weight of water. When so prepared, a mastic
composition is formed which is a substantially imporous
and homogeneous mixture having physical characteristics
of being self-adhering as a thick layer on an inverted
smooth surface and yet being separable therefrom as an
integral layer. When this mastic composition sets up
or dries (typical setting time is about 20 minutes at
normal ambient conditions), it becomes a hard, strong,
dimensionally stable, heat- and sound-resistant material
which is relatively light in weight with the expanded
beads being unbonded to one another and to the crystallized
gypsum and water.
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1()79172
If glass or other reinforcing fibers are included
in the expanded bead-slurry mixture, about 2% by weight
is admixed, and the glass fibers range in size from about
1" to about 2" in length and from about 0.005" to about
0.015" in diameter. When glass fibers are admixed with
the expanded bead-slurry mixture, a portion of expanded
beads is replaced by a substantially equal weight of
glass fibers. The interstitial volume of such a mastic
composition is that of a weight of expanded beads which
is substantially equal to the total weight of the expanded
beads and fiber glass. On a volumetric basis the rein-
forcing fiber content may be between about 1%-5% of the
total weight of the mastic composition.
Due in all probability to capillary action
principles and surface tension effects the ratios of
components and the sequence of mixing, the large volume
of expanded beads will quickly and easily mix with the
slurry rather than float and clump. The slurry is re-
tained within the interstices of the expanded beads or
at least does not separate, even though slurry volume
is somewhat in excess of the interstitial volume of the
beads. Further, as noted above, if a portion of the
expanded beads is replaced by a substantially equal weight
of glass fibers within the range given, the interstitial
volume remains substantially the same as that before a
1075~17Z
portion of the beads were removed, and substantially
the same volume of slurry is retained without signifi-
cant separation. The mastic composition is easily
handled and will form layers of uniform thickness and
has the property of being self-adhering on a smooth in-
verted surface but is easily separable therefrom as a
smooth integral layer.
Referring now to Fig. 2, a straight line manu-
facturing or production line or process is shown for
continuously forming composite structural panel uti-
lizing the mastic compositions previously discussed as
opposite facing layers in conjunction with a core of
paper honeycomb material.
There is shown generally at 1 a composite
structural panel fabricating or production line apparatus
comprising a source 3 from which is continuously supplied
unexpanded or compacted honeycomb core material 5, of kraft
paper or asbestos or the like, through an expander 7 there-
for, and a pair of upper and lower mastic composition
batchers and appliers 9,9a for applying layers of a mastic-
composition ll,lla onto two webs 13,13a of facing material
of kraft paper, or the like, supplied from separate roll sup-
plies or sources 15,15a thereof. The paper webs are trained
around a pair of pressing rolls 17,17a which urge their
mastic layers ll,lla into engagement with the upper and
107~172
lower faces of expanded honeycomb core 5a to continuously
form a composite structural panel 19 as it moves through
a compression conveyor 21 to a cutoff device 23 for
severing the panel into desired lengths.
More particularly, continuous honeycomb com-
paction 5, as shown also in Fig. 3, is supplied from
honeycomb source 3 by a delivery roll 27 to an expander
7 having a pair of converging sidewalls 29,31 which
engage opposite sides of the honeycomb compaction expanding
the cells to form expanded honeycomb material 5a a desired
width as it is drawn through the expander by a pair of
expanding rolls 33,33a which are drivingly engaged with
opposite faces 35,35a of continuous honeycomb core 5a.
A brake bar 37 of expander 7 is biased into engagement
with core face 35 to assist in controlling the expan-
sion of the honeycomb material to a predetermined open-
cell state as it is drawn through expander 7 by expan-
sion rolls 33,33a and fed to pressing rolls 17,17a.
Expanded honeycomb core 5a is drawn from rolls 33,33a
down a chute (not shown) by pressing rolls 17,17a. As
these rolls 17,17a draw the facing material 13,13a from
supply rolls 15,15a and beneath appliers 9,9a, relatively
thick mastic composition layers ll,lla are spread on
the smooth upper surfaces thereof. These batcher or
mixer-applicators may comprise apparatus of the type
1075~1~2
used to mix and e~trude bread dough. Lower web 13a
and its layer lla are advanced substantially in
straight line flow throug~ pressing rolls 17,17a where
lower mastic layer lla is pressed into lower core face
35a. However, the upper web of facing material 13 and
upper mastic layer 11 are inverted as they move through
an arc of approximately 180 about the periphery of
pressing roll 17 to a position wherein upper mastic layer
11 is opposite lower mastic layer lla and such layers are
now disposed between facing material 13,13a. In its in-
verted position, upper mastic layer 11 is pressed into
upper core face 35 by pressing roll 17 sllbstantially
simultaneously with the pressing of ~ower mastic layer
lla into lower core face 35a. Engagement of mastic layers
ll,lla with core faces 35,35a continuously forms composite
structural panel 19 as the superposed layers of paper
facing, mastic layers and honeycomb core move from press-
ing rolls 17,17a through compression conveyor 21. As
is well known in the art, compression conveyor 21 main-
tains even pressure against the webs 13,13a and masticlayers ll,lla while the mastic composition sets or dries
to the point that it is substantially dimensionally stable
and self-supporting. If desired, heating means (not shown)
may be used to accelerate drying of mastic layers ll,lla
as panel 19 passes through conveyor 21. Conveyor 21
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transports panel 19 to cut-off device 23 which auto-
matically severs continuous panel 19 into predeter-
mined desired lengths thereby to form individual com-
posite structural panels or segments 38. The mastic
composition may be mixed in batcher-spreaders 9,9a
or at a remote location and delivered through pipes
or the like to be spread as layers ll,lla.
As shown in Figs. 4 and 5, individual com-
posite structural panels 38 have upper and lower layers
ll,lla of set or dried mastic composition partially
embedded in and adhered to upper and lower faces 35,35a
of honeycomb core 5a, with facing material 13,13a adhered
to the outer facing surfaces of the layers. The low-
density, closed-cell, expanded synthetic resin beads,
such as expanded polystyrene beads 39 of the mastic
composition as previously discussed, are dispersed sub-
stantially evenly throughout the gypsum body 41 of
layers ll,lla thereby to provide substantially imporous
and homogeneous layers which, as set, are hard, strong,
dimensionally stable, and heat- and sound-resistant.
Paper honeycomb core 5a has a plurality of interconnecting
walls 43 forming a plurality of individual separate
cells 45, and upper and lower wall edges 47,47a con-
stitute opposite core faces 35,35a. A plurality of
16
107~172
openings or notches 49,49a are provided in edges 47,47a
extending inwardly of walls 43 a predetermined distance,
and each honeycomb cell 45 is provided with at least
one upper and lower opening or notch; however, any
number of upper and lower notches may be provided for
each cell, as desired. It should be noted that notches
49,49a constitute a means for predetermining the depth
of penetration of opposite core faces 35,35a into
layers ll,lla and also means for predeterminately con-
trolling thickness of layers ll,lla between the oppositecore faces and facing material 13,13a. While openings
49,49a are shown in the drawings as notches intersecting
edges 47,47a, it is also contemplated that other shaped
openings, such as for instance round or triangular holes
or elongate slots or the like, may also be employed,
and it may be noted that such openings may extend
through walls 43 between cells 45 of honeycomb core 5
being disposed adjacent edges 47,47a without intersecting
with the edges. During the manufacturing process previ-
ously described, it will be recalled that mastic layersll,lla are pressed into opposite core faces 35,35a and
thus penetrate past core edges 47,47a into each honey-
comb cell 45. When the layers penetrate into each cell
45 to the point shown in Figs. 4 and 5, i.e., just beyond
the inner ends of notches 49,49a, the notches are closed
~()75~
thereby to isolate each cell 45 from all others and
trap air therein. In this manner, trapped air in each
cell 45 forms a compressive cushion which opposes fur-
ther penetration of layers ll,lla inwardly into the
cells thereby to predetermine the penetration depth of
the layers into each cell. It should also be noted
that notches 49,49a while predetermining penetration
depths of layers ll,lla also controllably predetermine
the thickness of layers ll,lla between opposite core
faces 35,35a and facing material 13,13a thereby to
prevent engagement of opposite core faces with facing
sheets. As the penetration depth and rate of penetra-
tion of each layer are a function of the increasing
resistance of the mastic composition as it is moved
against and into the cell edges, an inherent substantial
self-centering of the core and equalization of layer
penetration take place.
In Figs. 6 and 7, apparatus is shown which
may optionally be used in conjunction with production
line 1 for applying strengthening or reinforcing fibers,
such as glass fibers 51, onto each mastic layer ll,lla
and thereafter working the applied glass fibers into the
mastic layers. For brevity only one such apparatus
is shown but another would be used for the other mas-
tic layer. A pair of chopper-spray guns 53 supplied
with fiber glass roving are provided in production line
1 between batchers 9,9a and pressing rolls 17,17a, and
18
1()75~172
a pair of vibrating rakes 55 are positioned downstream
of the guns in the production line.
More particularly, guns 53 are mounted for
reciprocal movement across moving mastic layers ll,lla
and the supporting webs of facing material 13,13a on a
pair of mounting rails 57 therefor. Glass fiber roving
is continuously fed from above (not shown) to guns 53
which chop the glass fibers fed thereto into lengths of
about 1 to 2 inches long and spray chopped glass fibers
51 onto the surfaces of mastic layers ll,lla. The recip-
rocal movement across mastic layers ll,lla on mounting
rails 57 permits guns 53 to apply or distribute glass
fibers substantially evenly onto the layers.
Vibrating rakes 55 extend entirely across
layers ll,lla. Tines or teeth 59 are provided on the rakes
extending generally angularly downwardly therefrom into
the layers. As rakes 55 are laterally vibrated, teeth
59 work or cause penetration of at least a portion of
glass fibers 51 from the top or exposed surface of layers
ll,lla downwardly into the layers.
Glass fibers 51, which are sprayed by guns 53
and penetrate into layers ll,lla by rakes 55, are shown
in Fig. 8 as dispersed layers ll,lla of individual com-
posite structural panel 38, and for brevity only the
layer lla is shown and discussed hereafter. It should
19
1075~Z
be noted that glass fibers 51 which are sprayed and
-aked into layer lla are more heavily concentrated
adiacent the inner surface thereof than adjacent facing
sheets 13a. The advantage of having glass fibers 51
more heavily concentrated adjacent the inner surface of
layer lla is that more glass fibers will extend through
notches 49a between adjacent honeycomb cells 45 and more
glass fibers will be adhered to honeycomb walls 43 and
edges 47a. In this manner, glass fibers 51 extending
through notches 49a between adjacent cells 45 provide
reinforcement or strengthening ties between the portions
of layers lla which penetrate into each cell, and glass
fibers adhering to honeycomb walls 43 and edges 47a pro-
vide a strong bond between honeycomb core 5a and layer
lla. The strengthening ties and adherence provided by
glass fibers 51 are desirable not only for panel streng-
thening purposes but also improve fire resistance ratings
as they maintain the integrity of the layer longer under
flame and fire conditions.
Referring now to Fig. 9, there is shown for
comparison glass fibers 51 which are admixed in the
expanded bead and slurry mixture, as previously discussed.
It should be noted that the admixed fibers 51 are more
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107~172
evenly dispersed throughout layer lla than those
fibers of Fig. 8 which were raked into layer lla.
The more evenly dispersed admixed ~lass fibers Sl
provide substantially even rather than preferential
reinforcement throughout layer lla, which may be pre-
ferred depending on the ultimate usage of the panel.
Thus the intended final use of composite structural
panels 38 dictates whether to spray and rake or admix
fibers 51 in order to achieve the particular disperse-
ment patterns thereof shown in Figs. 8 and 9.
Referring now to Figs. 10 and 11, the pro-
duction line 1 is shown in part and in conjunction with
means for interposing open-mesh reinforcing material
between facing material 13,13a and opposite faces 3S,35a
of honeycomb core 5a, embedded in mastic layers ll,lla.
More particularly, upper and lower webs or
layers of open wire mesh 61,61a are concertedly drawn
from sources thereof, such as upper and lower supply
rolls 62,62a and simultaneously fed through pressing
rolls 17,17a with facing sheets 13,13a, mastic layers
ll,lla and honeycomb core 5a substantially in the same
manner as previously described hereinabove with respect
to continuous forming of composite structural panel 19.
In this instance, wire mesh 61,61a is fed between webs
of facing material 13,13a and opposite core ~aces 35,35a
and becomes emb~dded in mastic layers ll,lla as they are
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107~17Z
pressed into engagement with opposite core faces
35,35a by pressing rolls 17,17a, as previously de-
scribed, thereby to form a continuous open-mesh rein-
forced composi~e structural panel 63 which is severed
into an individual composite structural panel length
or segment 65 in the same-manner as previously de-
scribed, portions of a panel 65 being shown in Figs.
12 and 13.
Panel 65 has all the component parts and
is formed substantially in the same manner as prev-
iously discussed composite structural panel 38 with
the exception that upper and lower webs of wire mesh
61,61a are embedded in upper and lower ~astic layers
ll,lla. The embedded wire mesh 61,6ia serves to re-
inforce and strengthen lay~rs ll,lla of composite
structural panel 65. ~hile metal wire mesh is par-
ticularly useful for facial reinforcement of composite
structural panel 65, it is to be understood that other
open mesh reinforcing material, such as made from syn-
thetic resin or natural fibers for example, may alsobe used. Also, glass fibers 51 can be included in
layers ll,lla with wire mesh 61,61a, and spray guns 53
and rakes 55 are compatible in the same production line
1 with wire mesh feeding rolls 62,62a. The combined
use of such additional apparatus in production line 1
is also within the scope of the invention.
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107gl7Z
In Figs. 14-16, there is shown generally
at 67 apparatus which also can be added to the pro-
duction line 1 thereby to merge or insert strips of
open-mesh reinforcing material 81,83,85 between separate
ribbons or lengths 71, 73, 75, 77 of honeycomb core
material which are disposed in side-by-side relation
generally having the same configuration and function
as the previously described honeycomb core 5a.
More particularly, separate ribbons 71, 73,
75 and 77 of expanded honeycomb core material are fed
from a source of compacted honeycomb material to press-
ing rolls 17,17a substantially in the same manner as
previously discussed with respect to Figs. 2 and 3.
Core lengths or ribbons 71, 73, 75 and 77 are delivered
in their predetermined open-cell state to the pressing
rolls 17,17a substantially in side-by-side relation with
each other but with lateral spaces 79 therebetween into
which a plurality of strips 81, 83, 85 of open-mesh
reinforcing material, such as expanded metal, are
inserted or mer~ed. Open-mesh reinforcing material of
plastic or natural fibers may also be used. Sources of
wire mesh strip, such as rolls 87, 89, 91 thereof, are
displaced laterally of production line 1, and wire mesh
strips 81, 83, 85 are drawn therefrom around a plurality
of rolls 93, 95, 97 which are positioned adjacent web
13a of facing material for aligning strips 81, 83, 85
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~079~72
with spaces 79 provided between honeycomb lengths 71,
73, 75, 77. Strips 81, 83, 85 are each disposed in
spaces 79 to extend substantially perpendicular to
the opposite faces 35,35a of core lengths 71,73, and
opposite edges 99,101 of the wire mesh strip are em-
bedded in layers ll,lla substantially to the same
depth of penetration as the core lengths 71,73. Wire
mesh strip 81 extends in a lengthwise direction of
composite structural panel 105 thereby to impart
strength thereto in the lengthwise direction as well
as between supporting layers ll,lla. As previously
mentioned, glass fibers 51 may be incorporated in
layers ll,lla if desired.
Referring now to Fig. 19, composite struc-
tural panels, such as any of the above discussed panels
38, 65 or 105, are shown in their erected positions, and
a pair of mating grooves 107 is provided in the oppo-
site sides of said panels between layers ll,lla and
their facing sheets 13,13a, the grooves extending for
the entire length of said panels. A tie or erection
bar 109 is received in each groove 107 in order to
maintain the side-by-side disposed panels in their
erected positions.
From the foregoing, it will be seen that
composite panels 38, 65 and 105, which include opposite
facing layers ll,lla of the hardened, substantially
24
~0~9172
imporous and homogeneous mastic compositions, de-
scribed herein, are light in weight forming a rigid
composite structure havin~ tensile, compression and
shear strengths meeting or surpassing conventional
drywall. This is due in part to the strength of
the honeycomb core, its low weight, the strong bond
cr adherence between layers ll,lla and honeycomb core
5a which is enhanced by the use of glass fibers 51
in the layers and also by the use of open-mesh rein-
forcing material 61,61a and 81 for reinforcing the
layers, and the superior properties of layers ll,lla.
When set, mastic composition layers ll,lla are dimen-
sionally stable, resisting warping,~d~istortion and
creeping, and provide a panel of uniform thickness with
a hard smooth ~inish with close tolerance surface flat-
ness. The unique method of controlling embedding of
layers ll,lla in the core 5a, i.e., trapping air in
each honeycomb cell 45 as previously discussed, pro-
vides for a high resistance to thermal and acoustic
transfer as well as absorbing and damping vibrations.
With regard to thermal resistance, glass fibers 51 in
layers ll,lla extending between cells 45 enhance the
integrity of the layers and the panel, particularly
when exposed to fire. Further, flame spread is mini-
mized since the only exterior combustible materials are
the thin paper facing material 13,13a and the material
which could be consumed by fire is less than 0.1~ of
the panel weight.
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10'7917Z
Composite structural panels 38, 65 and 105
also have a superior resistance to weathering and
ultraviolet rays and sunlight would only tend, over
an extended period of time, to slightly yellow the
facing surfaces of layers ll,lla, if unpainted. Fur-
ther, the composite structural panels of this inven-
tion resist transmission of water and vapor.
Composite structural panels 38, 65 and 105
exhibit product characteristics which are extremely
desirable from a structural and construction viewpoint.
For instance, the composite structural panels 38, 65,
105 are capable of being continuously formed with
very close thickness (+0.020") and flatness tolerances
(less than 0.020"/4' wide panel), and fabrication,
working and machining of the panels can easily be
accomplished by conventional hand or power tools since
the components thereof are puncture-resistant, i.e.,
any puncture is limited to the contact area without
chipping or radical cracking.
The apparatus and methods of this invention
provide fast (e.g., 5'/minute or 1200 sq.ft./hr.) and
economical production of these composite structural
panels.
26
10~ 172
In view of the above it will be seen
that the several objects of the invention are
achieved and other advantageous results attained.
As various changes could be made in the
above methods, constructions and products without
departing from the scope of the invention, it is
intended that all matter contained in the above
description or shown in the accompanying drawings
shall be interpreted as illustrative and not in a
limiting sense.
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