U.S. patent application number 09/981599 was filed with the patent office on 2002-04-04 for hinged thermoplastic-fabric reinforced structural member, profile and methods therefore.
This patent application is currently assigned to Andersen Corporation. Invention is credited to Puppin, Giuseppe.
Application Number | 20020038684 09/981599 |
Document ID | / |
Family ID | 24080527 |
Filed Date | 2002-04-04 |
United States Patent
Application |
20020038684 |
Kind Code |
A1 |
Puppin, Giuseppe |
April 4, 2002 |
Hinged thermoplastic-fabric reinforced structural member, profile
and methods therefore
Abstract
Useful hinged, structural members and profiles are disclosed
comprising thermoplastic-reinforcing fabric composite materials.
The hinged members and profiles have at least two rigid areas of
thermoplastic-fabric composite joined on a common fabric through
flexible, hinged regions. The hinged regions can comprise fabric
free of any thermoplastic composite forming material or
alternatively can be coated with flexible materials on one or both
sides of the fabric. The invention extends to co-extrusion methods
wherein thermoplastic materials are applied to pre-determined
portions of the fabric under pressure so that the thermoplastic
coats, and preferably wets, fibers of the reinforcing fabric. The
structural members thus extruded are formed into useful lengths and
readily converted into complex profiles by simple bending at the
hinged regions. In this way, complex profiles that would be
difficult to produce by conventional extrusion processes and bulky
to ship can be easily made at the job site.
Inventors: |
Puppin, Giuseppe; (Bayport,
MN) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Assignee: |
Andersen Corporation
Bayport
MN
|
Family ID: |
24080527 |
Appl. No.: |
09/981599 |
Filed: |
October 15, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09981599 |
Oct 15, 2001 |
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09522353 |
Mar 9, 2000 |
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09522353 |
Mar 9, 2000 |
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09252569 |
Feb 18, 1999 |
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Current U.S.
Class: |
156/88 ;
428/119 |
Current CPC
Class: |
E04F 19/022 20130101;
B29C 48/12 20190201; E04F 19/064 20130101; E04F 19/062 20130101;
Y10T 428/24174 20150115; B29L 2031/22 20130101; B29C 70/50
20130101; B29C 48/154 20190201 |
Class at
Publication: |
156/88 ;
428/119 |
International
Class: |
D06C 025/00 |
Claims
We claim:
1. A hinged, composite structure comprising a rigid thermoplastic
coated fabric having at least two pre-determined rigid composite
areas, said areas adjoining through at least one flexible hinged
region permitting rotation of one rigid area relative to another
about the hinged region.
2. The structure of claim 1, wherein said hinged region comprises a
linear region formed between said first and second rigid areas.
3. The structure of claim 2, wherein said linear region comprises a
flexible thermoplastic.
4. The structure of claim 3, wherein said flexible thermoplastic
encloses said fabric, said fabric free of rigid thermoplastic,
within said flexible regions.
5. The structure of claim 1, wherein pre-determined portions of
said rigid areas are non-coplanar.
6. The structure of claim 1, wherein said rigid areas include bends
at pre-determined distances from said flexible regions.
7. The structure of claim 1, wherein at least one fabric edge is
folded.
8. The structure of claim 7, wherein the width of said folded edges
is less than 5 centimeters.
9. The structure of claim 1, wherein said rigid areas have
properties comprising: (a) a modulus of elasticity of about 830
kpsi or greater; (b) a coefficient of thermal expansion of about
0.000022 in/in/.degree. F. or less; (c) a shrinkage not exceeding
about 0.28%; and (d) an impact of about 10 in-lbs or greater.
10. The structure of claim 9, wherein the standard deviations of
each listed property are within .+-.12% of the mean value.
11. The structure of claim 1 wherein the ratio of resin to fabric
of said first and second rigid areas comprises about 5 to 50 parts
by weight of fabric and about 50 to 95 parts of resin per each 100
parts of composite by weight.
12. The structure of claim 1, wherein said fabric is a woven
fabric.
13. The structure of claim 1, wherein said fabric is a non-woven
fabric.
14. The structure of claim 13, wherein said fabric is a glass fiber
containing fabric.
15. The structure of claim 14, wherein said first and second rigid
areas comprise about 70 to 90 parts by weight thermoplastic resin
and about 10 to 30 parts by weight glass fabric.
16. The structure of claim 14, wherein said glass fabric comprises
a plain weave fabric comprising about 5-20 ounces of fabric per
square yard.
17. The structure of claim 14, wherein said fabric is a 5-15 pick
fabric.
18. The method of claim 14 wherein said glass fabric further
comprises a surface coating on said glass fiber.
19. The structure of claim 18 wherein said surface coating
comprises a PVC coating.
20. The structure of claim 1, wherein said fabric is a polyamide
fiber containing fabric.
21. The structure of claim 1, wherein said fabric is a cellulosic
fiber containing fabric.
22. The structure of claim 1, wherein said thermoplastic comprises
polyvinylchloride.
23. The structure of claim 1, wherein said thermoplastic comprises
polyolefin.
24. The structure of claim 1, wherein said thermoplastic comprises
polyester.
25. A hinged profile comprising: (a) a rigid thermoplastic coated
flexible fabric having at least two pre-determined, non-coplaner
rigid composite areas, and (b) at least one flexible hinged region
joining said rigid areas.
26. The profile of claim 25, wherein said rigid areas include bends
at pre-determined distances from said flexible, hinged regions.
27. The profile of claim 25, wherein pre-determined portions of
said rigid areas are non-coplaner.
28. The profile of claim 25, wherein said hinged regions comprise
linear regions formed between said rigid areas.
29. The profile of claim 25, wherein said linear, hinged regions
comprise flexible thermoplastic.
30. The profile of claim 29, wherein said linear, hinged regions
are enclosed by flexible thermoplastic.
31. The profile of claim 25, wherein at least one fabric edge is
folded.
32. The profile of claim 31, wherein said folded edges have widths
less than 5 centimeters.
33. The profile of claim 25, wherein the width of the hinged region
(W) is related to bend angle .alpha. (in degrees), and radius of
curvature (R) by the equation:W=(.alpha..pi.R)/180.degree.
34. The profile of claim 25, wherein said rigid composite areas
have properties comprising: (a) a modulus of elasticity of about
830 kpsi or greater; (b) a coefficient of thermal expansion of
about 0.000022 in/in/.degree. F. or less; (c) a shrinkage not
exceeding about 0.28%; and (d) an impact of about 10 in-lbs or
greater.
35. The profile of claim 34, wherein the standard deviations of
each listed property are within .+-.12% of the mean values.
36. The profile of claim 25 wherein the ratio of resin to fiber of
said first and second rigid areas comprises about 5 to 50 parts by
weight of fabric and about 50 to 95 parts of resin per each 100
parts of composite by weight.
37. The profile of claim 25, wherein said profile comprises a sill,
a jamb, a track, or a sash.
38. The profile of claim 25, wherein said profile comprises a
hollow trim profile.
39. An exterior corner profile adapted to receive construction
panels by rotating said first and second rigid areas of the
structure of claim 1 shown in FIG. 1 through a clockwise bend angle
of 90 degrees.
40. An interior corner profile adapted to receive construction
panels by rotating said first and second rigid areas of the
structure of claim 1 shown in FIG. 3 through a counter-clockwise
bend angle of 90 degrees.
41. A method for making a hinged composite structure, said
structure including a rigid thermoplastic-fabric composite
comprising: (a) introducing fabric to the interior of an extrusion
die, (b) extruding rigid thermoplastic onto at least two
pre-determined areas of said fabric, (c) coating said
pre-determined areas with rigid thermoplastic to create a
composite, wherein said pre-determined areas are separated by a
linear flexible hinged region free of thermoplastic.
42. The method of claim 41, further comprising the step of
extruding flexible thermoplastic upon said hinged region.
43. The method of claim 41, wherein the process additionally
comprises a folding step in which at least one fabric edge is
folded prior to combination with said thermoplastic.
44. The method of claim 41, further comprising drawing composite
through a shaping die following said coating step wherein
pre-determined portions of said first and second rigid areas are
made non-coplaner.
45. A method for making a hinged, composite structure comprising a
thermoplastic coated glass fabric, the method comprising: (a)
introducing the glass fabric into a shaping station including a
shaping block to produce a pre-formed fabric shape conforming to
the shape of said hinged composite; (b) introducing at least one
rigid thermoplastic into a co-extruder having inlet zones and
combining zones wherein the thermoplastic(s) and preformed shaped
fabric are combined to form said composite structure under
conditions of sufficient pressure, temperature and shear to cause
the polymer composition to penetrate and wet individual glass
fibers to the extent that the polymer composition substantially
coats the glass fibers in said glass fabric; and (c) extruding the
thermoplastic-fabric composite through a shaping die to form said
structure wherein the properties of said rigid areas comprise: (i)
a modulus of elasticity of about 830 kpsi or greater; (ii) a
coefficient of thermal expansion of about 0.000022 in/in/.degree.
F. or less; (iii) a shrinkage not exceeding about 0.28%; and (iv)
an impact of about 10 in-lbs or greater.
46. The method of claim 45, further comprising the step of coating
said hinged regions with flexible thermoplastic.
47. The method of claim 45, further comprising a folding step
wherein a shaping block introduces at least one edge fold in said
fabric.
48. The method of claim 45 further comprising the step of
co-extruding flexible thermoplastic upon said hinged regions of
said fabric under temperature and pressure conditions sufficient to
bond flexible thermoplastic to the surfaces of said hinged
regions.
49. The method of claim 48, wherein the fabric of said hinged
region is entirely incorporated within said flexible
thermoplastic.
50. The method of claim 45, further comprising the step of passing
said fabric through a shaping block wherein the exterior edges of
said fabric are folded inward prior to introducing fabric into said
extrusion die.
51. A method for making a hinged profile comprising: (a)
introducing a fabric to the interior of an extrusion die, (b)
extruding rigid thermoplastic such that at least two pre-determined
rigid areas of thermoplastic coated fabric composite are created,
wherein said pre-determined rigid areas are separated by at least
one flexible hinged region free of thermoplastic, (c) removing
composite from said extrusion die, (d) cooling said composite, (e)
rotating said rigid areas relative each other about said hinged
regions to form said profile.
52. The method of claim 51, further comprising the step of
co-extruding flexible thermoplastic upon said hinged fabric
regions.
53. The method of claim 52, wherein said hinged regions are
entirely incorporated within said flexible thermoplastic.
54. The method of claim 51, further comprising the step of passing
said fabric through a shaping block wherein at least one exterior
fabric edge is folded inward prior to entry into said extrusion
die.
Description
RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. Ser. No.
09/252,569 filed Feb. 18, 1999.
FIELD OF THE INVENTION
[0002] The invention relates to a composite material comprising a
thermoplastic resin and a glass fiber fabric. The composite is
configured such that it can be formed into a useful complex profile
structural unit through simple manipulation of the glass fiber
composite. The resulting structural member can comprise a portion
of or the entirety of any structural unit. Preferably the members
used in the manufacture, reconstruction or repair of residential or
institutional construction. One important use of such structural
members is in the manufacture and repair of fenestration units such
as windows and doors for residential and commercial architecture.
More particularly, the invention relates to improved composite
materials and a co-extrusion process that produces structural
members that can be readily manipulated to form complex profiles.
The composite structures of the invention can be made to
manufacture structural components such as any member that finds use
in institutional or residential architectural and furniture
manufacturing applications.
BACKGROUND OF THE INVENTION
[0003] Structural materials have been made from composites
comprising a resin and a reinforcing material such as a fiber,
thread, yam, roving, fabric or other such fibrous material. Such
reinforcement materials have been used in a variety of
applications. Conventional window and door manufacturers have
commonly used wood and metal components in forming structural
members. Commonly, residential windows are manufactured from milled
wooden members, glass, screening fabric or extruded aluminum parts
that are assembled to form typically double hung or casement units.
Conventional glass-wooden windows while structurally sound, useful
and well adapted for use in many residential installations, can
deteriorate under certain circumstances. Conventional wood windows
can also require painting and other periodic maintenance. Wooden
and aluminum windows also suffer from cost problems related to the
availability of suitable material for construction. Clear wood
products are slowly becoming more scarce and are becoming more
expensive as demand increases. Metal components are often combined
with glass and formed into single unit sliding windows. Metal
windows typically suffer from substantial energy loss during winter
and summer months. Metal (aluminum and ferrous metals),
thermoplastic and wood materials can suffer from deterioration,
(i.e.) rust, rot, photochemical deterioration, etc.
[0004] Extruded thermoplastic materials have also been used as
non-structural components in window and door manufacture. Filled
and unfilled thermoplastics have been extruded into useful seals,
trim, weather-stripping, coatings and other window construction
components. Thermoplastic materials such as polyvinyl chloride have
been combined with wood members in manufacturing PERMASHIELD.RTM.
brand windows manufactured by Andersen Corporation for many years.
The technology disclosed in Zanini, U.S. Pat. Nos. 2,926,729 and
3,432,883, have been utilized in the manufacturing of plastic
coatings or envelopes on wood or other structural members.
Generally, the cladding or coating technology used in making
PERMASHIELD.RTM. windows involves extruding a thin polyvinyl
chloride coating or envelope surrounding a wood structural
member.
[0005] Polyvinyl chloride has been combined with wood fiber to make
extruded materials. Such materials have successfully been used in
the form of a structural member that is a direct replacement for
wood. These extruded materials have sufficient modulus, compressive
strength, coefficient of thermal expansion to match wood to produce
a direct replacement material. Typical composite materials have
achieved a modulus greater than about 500,000 psi, an acceptable
CTE, tensile strength, compressive strength, etc. to be useful.
Deaner et al., U.S. Pat. Nos. 5,406,768 and 5,441,801, U.S. Ser.
Nos. 08/224,396, 08/224,399, 08/326,472, 08/326,479, 08/326,480,
08/372,101 and 08/326,481 disclose a PVC/wood fiber composite that
can be used as a high strength material in a structural member.
This PVC/wood fiber composite has utility in many window and door
applications.
[0006] Kirk-Othmer Encyclopedia of Chemical Technology and other
such basic references contain a large proportion of information on
the formation of composite materials which are defined as
combinations of two or more materials present as separate phases
combined to form desired structures. Typically, composites have
fiber in some form combined with a continuous resin phase.
[0007] Oliveira, U.S. Pat. No. 4,110,510 teaches a PVC impregnated
mesh having barium sulfate coated chlorinated polyethylene
laminated to a sound deadening foam material.
[0008] Hutchinson et al., U.S. Pat. No. 4,463,046 discloses a
dual-durometer integral synthetic hinge joining two relatively
rigid synthetic resin sections. The inclusion of reinforcing
fibers, rovings, random fiber mats, and/or woven fabrics is not
disclosed.
[0009] Dost et al., U.S. Pat. No. 4,464,432 discloses a process for
manufacturing porous textile substrates and teaches a impregnated
substrate comprising fabric and a gelled thermoplastic under
pressure to impregnate the fabric.
[0010] Schock et al., U.S. Pat. No. 4,492,063 discloses extruded
plastic materials having glass fiber reinforced portions including
fiberglass mat or fabric.
[0011] Bafford et al., U.S. Pat. No. 4,746,565 discloses a flame
barrier comprising a face fabric laminated with a glass fabric
coated with an encapsulated coating.
[0012] Wahl et al., U.S. Pat. No. 4,885,205 discloses a fiberglass
mat or fabric impregnated with thermoplastic that is roughened or
pretreated with a needle.
[0013] Amotta, U.S. Pat. No. 5,045,377 discloses a composite grid
comprising a thermoplastic material is a grid format. The grid
components can be reinforced with fiberglass yam.
[0014] Laminates manufactured by inter-layering fiber mat or glass
fiber fabric with sheet-like thermoplastic materials have been
known. The inter-layered structures are often exposed to elevated
temperatures and pressures to form a mechanically stable laminate
structure.
[0015] The combination of a fiberglass mat or fabric with
thermosetting components are disclosed in Biefeld, U.S. Pat. No.
2,763,573 and Daray, U.S. Pat. No. 5,455,090 and Fennebresque et
al., U.S. Pat. No. 2,830,925.
[0016] A substantial and continuing need exists to provide an
improved composite material (using resins or polymers comprising
vinyl chloride and polymers having no chloride containing monomer
components) that can be made of thermoplastic resin or polymer and
a reinforcing fiber component. A further need exists for a
composite material that can be extruded into a shape that is a
direct substitute for the equivalent structural member milled shape
in a wood or metal structural member. A thermoplastic resin having
fiber or fabric compatibility, good thermal properties and good
structural or mechanical properties is required. This need also
extends to a composite with a coefficient of thermal expansion that
approximates wood, that can be extruded into reproducible stable
dimensions, a high modulus, a high tensile strength, a high
compressive strength, a low thermal transmission rate, an improved
resistance to insect attack and rot while in use and a hardness and
rigidity that permits sawing, milling, and fastening (nail, screw,
staple or glue) retention comparable to wood members.
[0017] Composite materials that comprise a fiber, fiberglass
roving, fiberglass mat or fabric combined with a thermoplastic have
been described. One common use of such thermoplastic fiber
composites is to make structural members useful in a variety of
applications. One type of structural member is a profile. A profile
typically is understood to comprise a linear member having
structural integrity that has a detailed cross-section. The
cross-section in detail renders the profile useful for a variety of
structural applications that commonly involve joining or
associating a variety of useful members in association with a
profile. Proper function of the profile in association with its
combined members often requires specific and detailed profile
shapes. Such shapes have been made by extruding composite pellets,
or by coextruding thermoplastic materials on fibrous mats or
fabrics.
[0018] In the production of profiles using extrusion methods for
making thermoplastic fabric composites, die complexity problems can
limit the shape of the extruded profiles.
[0019] Accordingly, a new extruded product and process for making a
hinged profile is needed.
BRIEF DISCUSSION OF THE INVENTION
[0020] A first embodiment of the invention provides a hinged,
structural member comprising a thermoplastic-fabric composite.
Unlike prior art fabric composites, the hinged member has two or
more rigid or semi-fabric areas coated with a rigid thermoplastic.
The rigid areas are joined by at least one flexible region that is
either uncoated or coated with flexible thermoplastic. The flexible
regions are typically linear permitting the rigid areas to rotate
relative to each other so that the hinged member can be bent or
folded into a complex profile. For consistency and simplicity,
"areas" refer to rigid or semi-rigid portions of the fabric coated
with rigid thermoplastic, and "regions" refer to the portions of
the fabric forming the hinge that either remain uncoated or are
coated with flexible thermoplastic. In the structural member, the
rigid areas immediately adjacent the hinged regions are
substantially co-planer therewith; however, in most applications
the rigid areas include bends at pre-determined distances from the
hinged regions.
[0021] A second embodiment of the invention provides a complex,
hollow profile that is formed by bending or folding the structural
member into a pre-determined shape. Therefore, the inventive
profile differs from the structural member in that upon bending the
member to form the profile the rigid areas adjacent the hinged
regions become non-co-planer. The pre-determined, geometries
envisioned for the inventive profiles can be complex with sharp
folds (bend angles) having small radii of curvature. Consequently,
the profiles impart a decorative and esthetic look uncommon in the
prior art and have utility in architectural and furniture finishing
applications. In most, but not necessarily all, profile designs the
bend angle .alpha. in degrees), radius of curvature (R) in mm, and
width of the hinged region (W) will be related as follows:
W=(.alpha..pi.R)/180.degree.
[0022] In both the inventive structural members and profiles, some
flexing of the rigid areas is envisioned especially when the rigid
areas are large; therefore their designation as semi-rigid is
appropriate. However, the radii of curvature of any such extensive
flexed areas are much larger than those of the bends and folds
contemplated in forming the profiles of the present invention. When
bent through the pre-determined bend angle and radius of curvature
of the profile, the rigid areas are expected to crack, fracture, or
shatter.
[0023] Therefore, for purposes of this invention, a rigid
thermoplastic is defined as a thermoplastic that fractures upon
bending the inventive composite through a pre-determined angle at a
specified radius of curvature. Conversely, a flexible thermoplastic
is defined as a thermoplastic that does not fracture upon bending
the inventive composite through a predetermined bend angle at a
specified radius of curvature.
[0024] A third embodiment of the invention provides a co-extrusion
process wherein thermoplastic and fabric are combined to form the
structural member. The process of the invention comprises
introducing a fabric material into an extruder having an extrusion
die. In the die, the rigid thermoplastic material is coextruded
with the fabric to form at least two rigid fabric-thermoplastic
composite areas joined by at least one flexible hinged region. The
hinged regions can be fabric regions free of rigid thermoplastic or
in alternative embodiments can have flexible thermoplastic
co-extruded thereon. Covering the hinged regions with a flexible
thermoplastic protects and seals them thus preventing elements of
the exterior environment from penetrating the fabric comprising the
hinge. The co-extrusion process delivers a hinged, composite,
structural member that after extrusion can be folded about the
flexible, hinged regions to form a complex, profile.
BRIEF DISCUSSION OF THE DRAWINGS
[0025] FIG. 1 shows an isometric view of a thermoplastic-fabric
composite structure including the hinged region of the invention
(as extruded) suitable for forming a complex, hollow profile
corresponding to an outside corner profile capable of receiving
construction panels.
[0026] FIG. 2 shows how the extruded structure of FIG. 1 can be
rotated clockwise through a bend angle (a) of 90 degrees to form a
hollow outside corner profile.
[0027] FIG. 3 shows an isometric view of another
thermoplastic-fabric structure including the hinged region of the
invention (as extruded) suitable for forming a complex, hollowing
profile corresponding to an inside corner profile capable of
receiving construction panels.
[0028] FIG. 4 shows how the extruded structure of FIG. 3 can be
rotated counter-clockwise through a bend angle (a) of 90 degrees to
form a hollow inside corner profile.
[0029] FIG. 5 shows the overall extrusion equipment used to make
the resin fabric composite of the invention. FIG. 5 includes a
fabric source, a resin source, a combining head, one or more
calibration blocks, and a cooling bath.
[0030] FIG. 6 shows a view of a fabric emerging from a pre-shaping
tool in which a flat fabric web is formed into a shape that
corresponds in shape to the die in which fabric and resin are
combined to produce the structure shown in FIG. 1.
[0031] FIG. 7 and 7A show the front and back surfaces of the
forming block useful for initiating folds at the edges of the
fabric web for the outside corner profile of FIG. 2.
[0032] FIG. 8 and 8A show the front and back surfaces of the
forming block useful for Initiating folds at the edges of the
fabric web for the inside corner profile of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
[0033] The invention relates to thermoplastic resin and continuous
glass fabric composite materials useful in forming hinged
structural members that can be folded to yield profiles having
complex cross-sections. The members exhibit high quality physical
properties because the fabric is intimately contacted and wetted by
the resin and organic materials thereby incorporating resin deep
within the fabric. The hinged composite members are made by
co-extrusion process wherein resin and fabric are combined and
formed into a linear extrudate having a pre-determined
cross-sectional geometry by means of a shaping die. The
cross-section can be any open or closed arbitrary shape depending
on the extrusion die geometry. During the extrusion process for the
resin/fabric composite, the resin and fabric are intimately
contacted at melt temperatures and pressures to insure that the
polymeric material flows into and through the fabric preferably
displacing trapped air and wetting glass fibers, so that on a
microscopic basis, coats and flows into the pores, cavity, etc., of
the fabric. Upon exiting the die the continuously extruded members
are cut to convenient lengths. The velocity of resin flow into
fabric is the sum of the pressure driven (Darcy flow) and capillary
(wicking) flows. The relative magnitudes of the two flows and
fabric fill time can be estimated using equations (7.3.11-13) as
described by Stokes and Evans, Fundamentals of Interfacial
Engineering, Wiley-VCH, 1997. pp 360-374, the disclosure of which
is hereby incorporated by reference. The Darcy flow is proportional
to the pressure differential and the square of the radius (or
width) of the flow channel. Capillary flow is proportional to the
surface tension, contact angle, and the first power of the radius
of the flow channel. Both flows are inversely proportional to the
viscosity of the resin. Therefore, the large interstices in the
fabric formed by weave fill rapidly and the flow slows down as it
enters and displaces the air trapped in the "pore like" void spaces
between individual glass filaments that make up the fiber bundles
(often called "rovings") comprising the "yarn" that is woven to
produce the glass fabric used to make the inventive composite. The
inventive method envisions the use of high pressure co-extrusion
processes to deposit thermoplastic onto the fabric surface and into
the porous strands suggesting that Darcy flow dominates the fabric
and fiber-filling event.
[0034] While the surface tension driven capillary flow may be
relatively unimportant during the coating process, it is the fiber
wetting process that determines the intimacy of the overall
fabric-resin bond which in turn determines the strength, impact
resistance, and weatherability of the composite. The capillary flow
associated with blade coating of glass fabric epoxy pre-preg
materials used in printed circuit boards has been estimated by Tait
et al. (Shell Patent U.S. Pat. No. 5,492,722].
Important Polymer Characteristics
[0035] Not every thermoplastic resin is useful in the composite
materials of the invention. First the thermoplastic resin must be
compatible with the glass fiber. Resins that are not compatible
with the glass fiber comprising the reinforcing fabric will not
sufficiently penetrate and wet the fabric to the degree necessary
to form the intimate bond between thermoplastic and fabric required
to obtain the engineering properties characteristic of the
inventive composite material.
[0036] The composite tensile moduli can be approximated from
formulae widely referenced in the art if values for the moduli and
volume fractions of the fabric and thermoplastic are known. Such
calculated estimates should be confirmed empirically by combining
resin and glass fiber at typical melt extrusion temperatures and
examining the interface between the polymer material and glass
fiber after the composite is cooled. Compatible fibers will form
intimate bonds with the glass fabric and will have no void portions
where the glass fiber is not contacted by resin. Non-compatible
resins can have reduced penetration into the glass fibers or can
have insufficient chemical compatibility to adhere to the glass
fiber in the fabric. The result of the incompatibility will be the
formation of voids and poor wetting of the fibers within the
fabric. Good wetting is required because moisture can penetrate
along the thermoplastic-fabric interface if voids are present,
leading to premature failure of the composite by delamination.
Compatible resins will quickly and easily flow into the fabric and
wet the glass fiber incorporating the resin into all fabric
openings.
[0037] Resin to fabric wetting can be increased using a pre-coated
fabric. For example, a thin PVC coating can improve wetting thus
increasing PVC resin to fabric adhesion. As discussed above,
increasing the pressure and decreasing the viscosity of molten
resin within the die will speed penetration of resin into fabric
weave interstices (where applicable) and fiber bundles thus
facilitating formation of a fully combined composite resin fabric
material.
[0038] To achieve optimum mechanical properties co-extrusion should
take place at a processing temperature substantially less than
about 450.degree. F. (340.degree. C.) preferably between 180 and
240.degree. C. Finally, the tensile moduli of characteristic areas
of rigid thermoplastic-fabric composite are greater than about
500,000 psi, preferably greater than 800,000 psi and can attain
values of 1.3.times.10.sup.6 psi or more.
[0039] The flexible thermoplastic polymers used to form the hinge
can be coextruded in those predetermined regions of the profile
where hinges are desired. Preferably the contemplated flexible
thermoplastics optionally used to coat the hinged regions likewise
wet, penetrate the fabric, and thermally bond with the surrounding
rigid thermoplastic areas during co-extrusion to seal the hinge
against penetration by water or noxious atmospheric pollutants such
as ozone, various oxides of nitrogen, and windblown particulates.
Plasticized PVC is an especially preferred flexible thermoplastic
because of its compatibility with the rigid PVC used to form the
rigid areas of the inventive profiles.
Vinyl Polymers
[0040] A large variety of vinyl polymeric materials can be used in
the composite materials of the invention.
[0041] A preferred vinyl polymer, a polyvinyl chloride homopolymer,
a copolymer of vinyl chloride and a second monomer and a polymeric
alloy having at least two vinyl polymers, at least one polymer
containing repeating units comprising vinyl chloride.
[0042] Polyvinyl chloride is a common commodity thermoplastic
polymer. Vinyl chloride monomer is made from a variety of different
processes such as the reaction of acetylene and hydrogen chloride
and the direct chlorination of ethylene. Polyvinyl chloride is
typically manufactured by the free radical polymerization of vinyl
chloride resulting in a useful thermoplastic polymer. After
polymerization, polyvinyl chloride is commonly combined with
thermal stabilizers, lubricants, plasticizers, organic and
inorganic pigments, fillers, biocides, processing aids, flame
retardants, and other commonly available additive materials.
Polyvinyl chloride can also be combined with other vinyl monomers
in the manufacture of polyvinyl chloride copolymers. Such
copolymers can be linear copolymers, branched copolymers, graft
copolymers, random copolymers, regular repeating copolymers, block
copolymers, etc. Monomers that can be combined with vinyl chloride
to form vinyl chloride copolymers include an acrylonitrile;
alpha-olefins such as ethylene, propylene, etc.; chlorinated
monomers such as vinylidene dichloride; acrylate monomers such as
acrylic acid, methylacrylate, methylmethacrylate, acrylamide,
hydroxyethyl acrylate, and others; styrenic monomers such as
styrene, alphamethyl styrene, vinyl toluene, etc.; vinyl acetate;
and commonly available ethylenically unsaturated monomer
compositions.
[0043] Such monomers can be used in an amount of up to about 50
mole-%, the balance being vinyl chloride. Polymer blends or polymer
alloys can be used. Such alloys typically comprise two miscible
polymers blended to form a uniform composition. Scientific and
commercial progress in the area of polymer blends has lead to the
realization that important physical property improvements cannot be
made by developing new polymer material by forming miscible polymer
blends or alloys. A polymer alloy at equilibrium comprises a
mixture of two amorphous polymers existing as a single phase of
intimately mixed segments of the two macro molecular components.
Miscible amorphous polymers form glasses upon sufficient cooling
and a homogeneous or miscible polymer blend exhibits a single,
composition-dependent glass transition temperature (T.sub.g).
Immiscible or non-alloyed blend of polymers typically displays two
or more glass transition temperatures associated with immiscible
polymer phases. In the simplest cases, the properties of polymer
alloys reflect a composition-weighted average of properties
possessed by the components. In general, however, the property
dependence on composition varies in a complex way with a particular
property, the nature of the components (glassy, rubbery or
semi-crystalline), the thermodynamic state of the blend, and its
mechanical state whether molecules and phases are oriented.
Polyvinyl chloride forms a number of known polymer alloys
including, for example, polyvinyl chloride/nitrile rubber;
polyvinyl chloride and related chlorinated copolymers and
terpolymers of polyvinyl chloride or vinylidene dichloride;
polyvinyl chloride/.alpha.-methyl styrene-acrylonitrile copolymer
blends; polyvinyl chloride/polyethylene; polyvinyl
chloride/chlorinated polyethylene; and others.
[0044] The primary requirement for the substantially thermoplastic
polymeric material is that it retain sufficient thermoplastic
properties to permit melt blending with optional wood fiber, and to
permit the composition material to be extruded or injection molded
in a thermoplastic process forming a rigid structural member.
Polyvinyl chloride homopolymers, copolymers and polymer alloys are
available from a number of manufacturers including B. F. Goodrich,
Vista, Air Products, Occidental Chemicals, etc. Preferred polyvinyl
chloride materials are polyvinyl chloride homopolymer having a
molecular weight (Mn) of about 90,000.+-.50,000, most preferably
about 88,000.+-.10,000. The preferred polyvinyl chloride has a bulk
density of approximately 0.71 gm/cc.+-.0.1 gm/cc.
[0045] Another class of thermoplastic includes styrenic copolymers.
The term styrenic copolymer indicates that styrene is
co-polymerized with a second vinyl monomer resulting in a vinyl
polymer. Such materials contain at least a 5 mole-% styrene and the
balance being 1 or more other vinyl monomers. An important class of
these materials is the styrene acrylonitrile (SAN) polymers. SAN
polymers are random amorphous linear copolymers produced by
co-polymerizing styrene acrylonitrile and optionally other
monomers. Emulsion, suspension and continuous mass polymerization
techniques have been used. SAN copolymers possess transparency,
excellent thermal properties, good chemical resistance and
hardness. These polymers are also characterized by their rigidity
dimensional stability and load bearing capability. Olefin modified
SAN's (OSA polymer materials) and acrylic styrene acrylonitriles
(ASA polymer materials) are known. These materials are somewhat
softer than unmodified SAN's and are ductile, opaque, two phased
terpolymers that have surprisingly improved weatherability.
[0046] ASA resins are random amorphous terpolymers produced either
by mass co-polymerization or by graft co-polymerization. In mass
co-polymerization, an acrylic monomer styrene and acrylonitrile are
combined to form a heteric terpolymer. In an alternative
preparation technique, styrene acrylonitrile oligomers and monomers
can be grafted to an acrylic elastomer backbone. Such materials are
characterized as outdoor weatherable and UV resistant products that
provide excellent accommodation of color stability property
retention and property stability with exterior exposure. These
materials can also be blended or alloyed with a variety of other
polymers including polyvinyl chloride, polycarbonate, polymethyl
methacrylate and others. An important class of styrene copolymers
includes the acrylonitrile-butadiene-styrene monomers. These resins
are very versatile family of thermoplastic resins produced by
co-polymerizing the three monomers. Each monomer provides an
important property to the final terpolymer material. The final
material has excellent heat resistance, chemical resistance and
surface hardness combined with processability, rigidity and
strength. The polymers are also tough and impact resistant. The
styrene copolymer family of resins has a melt index that ranges
from about 0.5 to 25, preferably about 0.5 to 20.
[0047] An important class of resins that can be used in the
composites of the invention include acrylic resins. Acrylics
comprise a broad array of polymers and copolymers in which the
major monomeric constituents are an ester acrylate or methacrylate.
These resins are often provided in the form of hard, clear sheet or
pellets. Acrylic monomers polymerized by free radical processes
initiated by typically peroxides, azo compounds or radiant energy.
Commercial polymer formulations are often provided in which a
variety of additives are modifiers used during the polymerization
provide a specific set of properties for certain applications.
Pellets made for resin grade applications are typically made either
in bulk (continuous solution polymerization), followed by extrusion
and pelletizing or continuously by polymerization in an extruder in
which unconverted monomer is removed under reduced pressure and
recovered for recycling. Acrylic plastics are commonly made by
using methyl acrylate, methylmethacrylate, higher alkyl acrylates
and other co-polymerizable vinyl monomers. Preferred acrylic resin
materials useful in the composites of the invention has a melt
index of about 0.5 to 50, preferably about 1 to 30 gm/10 min.
[0048] Vinyl polymer resins include a acrylonitrile; alpha-olefins
such as ethylene, propylene, etc.; chlorinated monomers such as
vinylidene dichloride, acrylate monomers such as acrylic acid,
methylacrylate, methylmethacrylate, acrylamide, hydroxyethyl
acrylate, and others; styrenic monomers such as styrene,
alphamethyl styrene, vinyl toluene, etc.; vinyl acetate; and other
commonly available ethylenically unsaturated monomer
compositions.
1 RESIN PARAMETERS USEFUL PREFERRED PROCESS TEMPERATURE T
<250.degree. C. 150.degree.-210.degree. C. FLEX MODULUS* (RESIN
>200,000 >300,000 Only)
Condensation Polymer Resins
[0049] Condensation polymer resins that can be used in the
composite materials of the invention include polyamides,
polyamide-imide polymers, polyarylsulfones, polycarbonate,
polybutylene terephthalate, polybutylene naphthalate,
polyetherimides, polyethersulfones, polyethylene terephthalate,
thermoplastic polyimides, polyphenylene ether blends, polyphenylene
sulfide, polysulfones, thermoplastic polyurethanes and others.
Provided the materials can be coextruded at temperatures less than
250.degree. C., preferred condensation resins include polycarbonate
materials, polyphenyleneoxide materials, and polyester materials
including polyethylene terephthalate, polybutylene terephthalate,
polyethylene naphthalate and polybutylene naphthalate
materials.
[0050] Polycarbonate resins are high performance, amorphous
thermoplastic resins having high impact strength, clarity, heat
resistance and dimensional stability. Polycarbonates are generally
classified as a polyester or carbonic acid with organic hydroxy
compounds. The most common polycarbonates are based on phenol A as
a hydroxy compound co-polymerized with carbonic acid. Materials are
often made by the reaction of a bisphenol A with phosgene
(COCl.sub.2). Polycarbonates can be made with phthalate monomers
introduced into the polymerization extruder to improve properties
such as heat resistance, further tri-functional materials can also
be used to increase melt strength or extrusion blow molded
materials. Polycarbonates can often be used as a versatile blending
material as a component with other commercial polymers in the
manufacture of alloys. Polycarbonates can be combined with
polyethylene terephthalate acrylonitrile-butadiene-styrene resins,
styrene maleic anhydride resins and others. Preferred alloys
comprise a styrene copolymer and a polycarbonate. Preferred melt
for the polycarbonate materials should be indices between 0.5 and
7, preferably between 1 and 5 gms/10 min.
[0051] A variety of polyester condensation polymer materials
including polyethylene terephthalate, polybutylene terephthalate,
polyethylene naphthalate, polybutylene naphthalate, etc. can-be
useful in the resin glass fabric fiber thermoplastic composites of
the invention. Polyethylene terephthalate and polybutylene
terephthalate are high performance condensation polymers. Such
polymers often made by a co-polymerization between a diol (ethylene
glycol, 1,4-butane diol) with dimethyl terephthalate. In the
polymerization of the material, the polymerization mixture is
heated to high temperature resulting in the trans-esterification
reaction releasing methanol and resulting in the formation of the
condensate material. Similarly, polyethylene naphthalate and
polybutylene naphthalate materials can be made by co-polymerizing
as above using as an acid source, a naphthalene dicarboxylic acid.
The naphthalate thermoplastics have a higher T.sub.g and higher
stability at high temperature compared to the terephthalate
materials. However, all these polyester materials are useful in the
composite structural materials of the invention. Such materials
have a preferred molecular weight characterized by melt flow
properties. Useful polyester materials have a viscosity at
265.degree. C. of about 500-2000 cP, preferably about 800-1300
cP.
[0052] Polymer blends or polymer alloys can be useful in
manufacturing the linear extrudate of the invention. Such alloys
typically comprise two miscible polymers blended to form a uniform
composition. Scientific and commercial progress in the area of
polymer blends has lead to the realization that important physical
property improvements can be made not by developing new polymer
material but by forming miscible polymer blends or alloys. A
polymer alloy at equilibrium comprises a mixture of two amorphous
polymers existing as a single phase of intimately mixed segments of
the two macro molecular components. Miscible amorphous polymers
form glasses upon sufficient cooling and a homogeneous or miscible
polymer blend exhibits a single, composition dependent glass
transition temperature (T.sub.g). Immiscible or non-alloyed blend
of polymers typically displays two or more glass transition
temperatures associated with immiscible polymer phases. In the
simplest cases, the properties of polymer alloys reflect a
composition weighted average of properties possessed by the
components. In general, however, the property dependence on
composition varies in a complex way with a particular property, the
nature of the components (glassy, rubbery or semi-crystalline), the
thermodynamic state of the blend, and its mechanical state whether
molecules and phases are oriented.
[0053] The primary requirement for the substantially thermoplastic
resin material is that it retain sufficient thermoplastic
properties to permit melt blending with glass fabric fiber, permit
formation of linear structural members, and to permit the
composition material to be extruded in a thermoplastic process
forming the rigid structural member. Thermoplastic resin and resin
alloys are available from a number of manufacturers including B.F.
Goodrich, G.E., Dow, and DuPont.
[0054] The composite of the invention comprises a woven or
non-woven glass fiber fabric, which has preferably been given a
protective coating to coat individual glass fibers, yams, etc.
Suitable woven glass fiber fabrics include fabrics having a plain
weave, a basket weave, a twill weave, and a crowfoot satin or long
shaft satin weave. Suitable knit fabrics include warp knits and
weft knits. Non-woven glass fabrics are also suitable but not
preferred. The construction of the fabric should not be such that
the composite, whether or not prelaminated, precoated or
preprocessed, results preventing breakage, splitting or bending of
any of the individual glass fibers, past a mechanical yield point,
prior to non-woven fabric formation. Fabric weights from about 0.5
to about 10 ounces per square yard are suitable. The preferred
fabric for the purpose of this invention comprises a glass fiber
fabric having a PVC, acrylic or acrylate coating. The preferred
glass fabric is a plain weave fabric having about 5-20, preferably
about 7-12 ounces of fabric per square yard. The fabric typically
includes about 10 to 30 bundles of fiber per each square inch
(known in the fabric industry as "10-30 pick") in the fabric here
each bundle contains about 40 to about 5.000 glass strands
typically 200 to 1000 strands.
[0055] Fabrics can be made from individual glass fibers, individual
yarns, collections of 2 to greater than 100 individual fibers,
tows, yarns or other collections. Further, the fabrics can contain
non-glass fibers such as carbon fiber, Kevlar.RTM. fiber, metal
fibers or other high performance fiber having a tensile strength
approximating or greater than that of glass fiber. Such fibers can
be included in a glass fiber yarn or tow or can be individually
introduced into the woven or non-woven fabric at random in either
the warp or weft or both. In the manufacture of non-woven fabrics,
the non-woven fabric can be a single layer of randomly distributed
glass fiber or yarn or multi-layer laminates of fiber or yarn
distribution fabrics. Such non-woven fabrics can also include
non-glass fiber incorporated with the glass fiber or between the
glass fiber laminations. The glass fiber is preferably coated to
encapsulate the glass in a coating. The coating increases the
wetability (adjust the surface energy) of the glass fiber to render
the materials more compatible or wetable with the synthetic resin
or resin blend. Typical coating compositions generally contain a
polymeric binder material combined with a filler, a fire retardant
additive, a pigment or a plasticizer, or other typical fabric
additive material. Typical binders include polymeric materials that
can be dissolved or suspended in aqueous diluents including
emulsion polymers such as polyvinyl chloride, polyurethane
polymers, acrylic materials, ethylene/vinyl chloride copolymers,
vinylidene chloride/alkylmethacrylate copolymers, vinyl
chloride/vinylacetate copolymers, neoprene brand (isoprene or
chloroprene) polymers, vinylacetate/alkylacrylate copolymers or any
known combination thereof. Typical filter materials are commonly
inorganic and include clay, calcium carbonate, talc or titanium
dioxide. Fire retardant additives include chlorine containing
polymers, antimony trioxide, antimony pentaoxide, aluminum
trihydrate and decabromodiphenyloxide.
[0056] Depending on the selection of polymeric binder, a
plasticizer may be incorporated into the composition to maximize
flexibility of the coated glass fabric. A wide variety of organic
plasticizers are suitable and known for obtaining a flexible
coating. A large number of clear plasticizers are known. The
coating is commonly applied to the glass fabric as liquid coating
or a collapsible foam that can penetrate the glass fiber yams to
ensure that each glass fiber is fully coated. Suitable methods for
applying a liquid coating include tank coating, gravure coating, a
reverse role coating, knife over roll coating, knife over table
coating, floating knife methods, dip coating or pad/nip coating.
The coating technique is not critical as long as each glass fiber
is substantially coated or encapsulated. The amount of coating
applied to the glass fibers can range from about 5 to about 95 wt %
based on the coated glass fiber, preferably about 8 to 30 wt %
based on the weight of the glass fiber. The coating on the fiber
material can comprise one, two or more of a similar or diverse
coating. A second or third coating can comprise a primer coating
optimizing wetability of the glass fiber by the polymer material.
Such primers include organo silanes, organo titanates, polyurethane
coatings, etc.
2 RESIN/FABRIC COMPOSITE PARAMETERS USEFUL PREFERRED FLEX MODULUS*
>500,000 >700,000 COEFFICIENT OF <2.5 .times. 10.sup.-5
<1.5 .times. 10.sup.-6 THERMAL EXPANSION in/in-.degree. F.
in/in-.degree. F. HEAT DISTORTION T >95.degree. C. T
>105.degree. C. TEMPERATURE IMPACT ENERGY - >4 in-lb about 10
to 35 SINGLE LAYER GLASS in-lb COMPOSITE
Composite Manufacture
[0057] In the manufacture of the composition of the invention, the
manufacture and procedure requires two important steps. A first
fabric preform step and a second resin/fabric extrusion step.
[0058] In a preferred mode, the glass fabric or two or more fabric
or glass plies is pre-formed into an appropriate shape prior to
combination with the appropriate resin material. We have found that
including the pre-form step of pre-shaping the glass fiber to that
of a final structural member, facilitates the coextrusion process.
Especially when an edge fold is introduced along a lateral edge
passes into the coextrusion die. The folded fabric can also have
any arbitrary shape. Such a shape can include a simple angle such
as a 90.degree. angle, a 135.degree. angle, a 45.degree. angle or
other such angle. Further, the preformed shape can be a simple or
complex curve having one, two or more diameters. The curves can be
convex on one side and concave on that same side. Further, the
glass fiber can be formed into a closed surface having a
triangular, square, rectangular, circular, oval, hexagonal,
heptagonal or other cross-section. The glass fabric can be formed
into virtually any arbitrary shape conforming to the end use.
[0059] Such shapes can conform to a circular or oval cross-section
tube, a rail, a quarter-round, half-round or other shape, a jamb a
hollow or filled style, a sill having portions of the linear
extrudate shaped to the form of a double hung member, a track shape
having a passageway for one, two or more units such as a track for
a double hung window, a sliding glass door, etc. The member can
comprise stop or sash members or can comprise portions that are
non-structural trim elements such as grill, cove, bead,
quarter-round, repair pieces, etc. Such a preshaping step is
typically accomplished by interposing a shaping member between the
source of fabric and the extrusion die that contacts the melt
polymer with the glass fabric. Such a shaping die can comprise a
simple die which forms the glass fabric into an appropriate shape
or can comprise a series of dies that slowly conforms the glass
into an appropriate shape for combination with the melt polymer.
Such a step wise confirmation of the fabric into the appropriate
shape can be done smoothly with a smoothly changing surface that
conforms the glass into an appropriate shape. Further, such a
pre-forming step can be done in discrete stages in which the glass
fabric passes through two, three or more shaping stages resulting
in the formation of a final profile product.
[0060] An important pre-forming step with respect to forming a
stable useful strong composite involves introducing a fold into an
edge on the exposed fiber. We have found fabric, as is common to
virtually all fabric, can fray at an edge. This fraying is commonly
made worse by application of a flow of resin against the exposed
fabric edge disrupting the warp and weft of the fabric. The frayed
edges can have randomly oriented fiber and can have fiber removed
from the weave resulting in a poorly formed edge with
unsatisfactory geometry. Such problems can be solved by introducing
a fold into each edge of the fabric. Typically, the edges folded
are the lateral edges in the sense that the edges are on the sides
of materials as they are incorporated into the extrusion machines.
The leading edge and following edges are often not folded during
operations, only the lateral edges are exposed to the effects of
melt resin. A single fold can be used, however, a double fold or
triple fold can be used resulting in a structure having two, three,
four or more layers of fabric in the fold. The fold width, measured
from the lateral edge of the fold can be approximately 0.1 to 5
centimeters, preferably about 0.2 to 3 centimeters. The folding or
pre-forming can be done in one or more stations or steps. We have
found that prefolding the fabric prior to the introduction of melt
fiber results in a strengthened edge and an edge in which the
folded materials, incorporated with resin are strong, resilient and
resist mechanical stress. The prefold can be achieved using a
pre-forming die that folds the edges over. Such a die can be
installed before or after the pre-shaping die shown in FIG. 5.
Alternatively, the folding and pre-shaping step is done in a single
tool.
[0061] In the preferred mode, extruders are used to melt and
deliver thermoplastic resin to the co-extrusion die wherein fabric
and resin are combined to form the inventive composite Suitable
extruders can be obtained from a variety of manufacturers including
Cincinnati Millicron, Davis-Standard, etc. They are multistage
units that control the processing temperature profile as
thermoplastic passes through an optional pre-heater, mixing
section, a transport section and melt section as is well known in
the art. The resin fed to the extruder preferably has a small
particle size which is mostly commonly in the form of flake,
pellet, powder, etc. Typical resin feed rates are about 60 to about
1400 pounds of material per hour.
[0062] In the preferred mode, fabric and polymer are fed to the
co-extrusion die at a rate such that the composite can comprise
from about 1 to 50 wt % of fabric and 50 to 99 wt % resin.
Preferably, about 10 to 20 wt % fabric is combined with 80 to 90 wt
% of resin wherein the pre-formed and optionally folded fabric is
intimately contacted and combined with molten thermoplastic.
Ideally the die is designed so that the melt resin contacts
opposite sides of the shaped fabric. However, in some applications
this is not possible, and resin is supplied to only one side of the
fabric under sufficient pressure to force the melt into and through
the fabric resulting in some resin covering all fiber surfaces.
Upon exiting the die the continuous linear extrudate forming the
inventive hinged, structural member is cut into useful lengths. The
cross-section of the member can be any open or closed arbitrary
shape depending on the extrusion die geometry.
[0063] In summary, we have found that the interaction, on a
microscopic level, between the resin and the fabric, in one, two or
more layers or plies of fabric, is an important element of the
invention. The physical properties of an extruded member are
improved when the polymer melt during extrusion of the linear
member thoroughly wets and penetrates the fiber in the fabric. The
thermoplastic material comprises an exterior continuous organic
resin phase covering and intimately associated with reinforcing
fiber/fabric. This means, that any pore, crevice, crack,
passageway, indentation, etc., in the warp and weft is fully filled
by thermoplastic material. Such penetration as attained by ensuring
that the viscosity of the resin melt is reduced by operations at
elevated temperature and the use of sufficient pressure to force
the polymer into the available internal pores in and on the surface
of the fiber or fabric. During the linear extrudate manufacture,
substantial work is done in providing a uniform introduction of
resin into fabric.
Detailed Discussion of the Drawings
[0064] FIG. 1 shows a hinged, structural member of the invention
(as extruded) suitable for forming an outside corner. The hinge 107
is shown at the center of symmetry. The PVC hinged composite 100 is
formed over a fabric 101 that can be a Kevlar, glass, cellulosic or
other woven or non-woven fabric. The fabric 101 is formed into a
first rigid composite area 106 and a second rigid composite area
106a by coating the fabric 101 with rigid polyvinylchloride 102 to
form the composite areas 106 and 106a. At the periphery of the
composite areas are folds 105 and 105a introduced into the fabric
edge to ensure a smooth, non-raveling, strong composite periphery.
The composite areas 106 and 106a are coextruded areas in which the
rigid PVC intimately contacts and wets individual fibers in the
fabric forming a strong integral composite structure. Between
composite areas 106 and 106a is a region 107 comprising fabric 103
free of rigid PVC. Hinge 107 is formed by a substantially linear
region separating rigid composite areas 106 and 106a wherein in one
embodiment of the invention uncoated flexible fabric joins rigid
composite areas 106 and 106a. In another embodiment of the
invention, hinged area 107 can be coated on one or both sides with
a flexible resinous sealant 104 sealing hinged area 107. Such a
sealant is useful in ensuring that the fabric does not permit
passage of atmospheric gases, moisture, rain, dust, pollen or other
material that can penetrate and disrupt the thermoplastic-fabric
bond.
[0065] FIG. 2 shows how the hinged profile shown in FIG. 1 is
transformed into a finishing cap for an outside corner by rotating
the rigid composite area 106 with respect to composite area 106a in
a 90.degree. arc to form finishing cap structure 200 shown in FIG.
2. The structure 200 of FIG. 2 comprises the co-extrusion formed on
the fabric 101 using a coextruded rigid PVC layer 102 forming the
composite structure 200. The rigid areas 106 and 106a are rotated
with respect to one another about hinge 107 to form the structure
200. Cap structure 200 includes fabric 101, coextruded PVC layer,
102, edge fold 105 that maintains an intact peripheral edge,
sealant 104 on the exterior facing side of hinged area 107, and
sealant free fabric surface 103 on the interior facing side portion
of cap structure 200. As shown, structure 200 exhibits mounting
areas 202 and 202a that are adapted for the insertion of a panel
203 or 203a in the assembly of residential or institutional
architecture. In this application structure 200 comprises an
outside corner profile or assembly device that can be installed
over an outside corner 205 for the purpose of providing a finished
look after the installation of the panel members 203 and 203a. In
such a construction application, the structure 200 is placed over
rough corner 205 and rigid composite areas 106 and 106a attached to
corresponding outside corner surfaces 206 and 206a using fasteners,
adhesives, or heat fusion techniques. Once in place, wall panels
203 or 203a are inserted into the slots 202 or 202a and are fixed
in place again using fasteners or adhesive technology.
[0066] FIG. 3 shows a hinged structural member of the invention (as
extruded) suitable for forming an inside corner. The hinge 107 is
shown at the center of symmetry. The PVC hinged composite 300 is
formed over a fabric 101 that can be a Kevlar, glass, cellulosic or
other woven or non-woven fabric. The fabric 101 is formed into a
first rigid composite area 106 and a second rigid composite are
106a by coating the fabric 101 with rigid polyvinylchloride 102 to
form the composite areas 106 and 106a. At the periphery of the
composite area are folds 105 and 105a introduced into the fabric
edge to ensure a smooth, non-raveling, strong composite periphery.
The composite areas 106 and 106a are coextruded areas in which the
rigid PVC intimately contacts and wets individual fibers in the
fabric forming a strong integral composite structure. Between
composite areas 106 and 106a is a region 107 comprising fabric 103
free of rigid PVC. Hinge 107 is formed by a substantially linear
region separating rigid composite areas 106 and 106a wherein in one
embodiment of the invention uncoated flexible fabric joins rigid
composite areas 106 and 106a. In another embodiment of the
invention hinged area 107 can be coated on one or both sides with a
flexible resinous sealant 104 sealing hinged area 107. Such a
sealant is useful in ensuring that the fabric does not permit
passage of atmospheric gases, moisture, rain, dust, pollen or other
material that can penetrate and disrupt the thermoplastic-fabric
bond.
[0067] FIG. 4 shows how the hinged profile shown in FIG. 3 is
transformed into a finishing insert for an inside corner by
rotating the rigid composite area 106 with respect to composite
area 106a in a 90.degree. arc to form finishing insert structure
400 shown in FIG. 4. The structure 400 of FIG. 4 comprises the
coextrusion formed on the fabric 101 using a coextruded rigid PVC
layer 102 forming the composite structure 400. The rigid areas 106
and 106a are rotated with respect to one another about hinge 107
ultimately contacting at an interface 204, which can be fixed by
mechanical fasteners, adhesives, heat fusion or other technique to
form the structure 400. Insert structure 400 includes fabric 101,
coextruded PVC layer, 102, edge fold 105 that maintains an intact
peripheral edge, sealant 104 on the exterior facing side of hinged
area 107, and sealant free fabric surface 103 on the interior
facing side portion 401 of insert structure 400. As shown,
structure 400 exhibits mounting areas 202 and 202a that are adapted
for the insertion of a panel 203 or 203a in the assembly of
residential or institutional architecture. In this application
structure 400 comprises an inside corner profile or assembly device
that can be inserted into an inside corner 405 for the purpose of
providing a finished look after the installation of the panel
members 203 and 203a. In such a construction application, the
structure 400 is inserted into rough corner 405 and rigid composite
areas 106 and 106a attached to corresponding outside corner
surfaces 406 and 406a using fasteners, adhesives, or heat fusion
techniques. Once in place, wall panels 203 or 203a are inserted
into the slots 202 or 202a and are fixed in place using fasteners
or adhesive technology.
[0068] Process for Making the Hinged Profile of the Invention
[0069] FIG. 5 shows an overall apparatus used for forming the resin
fabric composite of the invention. The device 10 generally shows a
co-extruder head (die) 11 in which fabric and resin are combined
under conditions of temperature and pressure sufficient to
incorporate the resin into the fabric. Fabric is provided from
fabric source 12, typically a rolled cylinder of fabric, and is
preformed (shaped or folded) into a desired shape using a
pre-forming or folding shaping blocks (examples of which are shown
in FIGS. 7 and 7A and 8 and 8A and described in detail in the
discussion thereof). Fabric enters co-extrusion head 11 through a
die entry aperture (not shown) wherein it is combined with melt
resin and optional flexible polymer used to form hinge 107. Melt
resin 19 and flexible polymer is fed to co-extrusion head 11
through heated ports 13 and 13a from extrusion apparatus
(extruders) (not shown). In pressurized co-extruder head 11, resin
and flexible polymer are applied and combined with pre-determined
regions of fabric 12. The hinged composite 14 comprising fabric,
hot resin, and flexible hinge exits the die at die exit 15. The
surfaces of the fabric are contacted with melt resin and optional
flexible polymer in the extruder head on one or both sides from
supply channels formed in the extruder device. The dimensions of
the die gates contained with the co-extruder head are modified to
ensure that every part of the fabric is contacted with appropriate
amounts of resin. The peripheral edges typically have greater
dimensions to ensure that melt resin can flow and wet the periphery
of the fabric. In particular, the folded edges of the fabric
require additional resin to fully fill the interstices of the
double (multiple) fabric layers of the folded edge. The internal
components of the die are not shown. After exiting the die at exit
15, the hot resin fabric composite is directed into a calibration
block 16 that ensures the continuous composite profile shape is
exact within required tolerances. Such vacuum calibration blocks
are commonly available in the industry examples of which are shown
in U.S. Pat. Nos. 5,468,442 (Brambilla); and 5,316,459 (Melkonian
et al.). These blocks reduce the temperature of the composite such
that the constant dimensions are maintained as the composite enters
a cooling bath 17. The cooling bath is typically filled with water
to a level 18. The flow of cooling water in the water bath reduces
the temperature of the composite to approximately ambient
temperature. Finally, commercial embodiments of the inventive
process contemplate using means for continuously monitoring and
controlling the tension of the fabric web as it passes through the
shaping blocks, co-extrusion coating head (die), calibration blocks
and cooling tank, and profile tractor.
[0070] FIG. 6 is a view of an apparatus 600 that introduces a
desirable shape into the glass fabric prior to combination with the
melt resin. To simplify the perspective view of preshaped input
glass fabric of outside corner profile of FIG. 1 has been truncated
along section A-A. FIG. 6 shows the apparatus 600 that introduces
the preformed shape 601 into fabric 602. The flat, unshaped input
fabric 12 of FIG. 5 is fed directly into the apparatus inlet 603 of
shaping block 604 where the fabric takes on a shape fixed by the
dimensions of the inlet. The inlet 603 is sized in dimension to
correspond to the thickness of the fabric leaving less than 0.015
inch clearance upon entry. The forming apparatus 600 contains no
introduction ports adapted for melt resin and is merely a
pre-shaping apparatus for the fabric. Immediately downstream of the
shaping apparatus 600 the pre-formed fabric enters co-extrusion
head 11 shown in FIG. 5 where pressurized resin and flexible hinge
polymer are forced into fabric interstices where it penetrates the
fiber bundles and wets individual fibers thus forming the inventive
composite.
[0071] FIG. 7A shows the entrance surface of wooden forming block
700 used in making the outside corner structural member of FIG. 1.
Fabric from supply roll 12 shown in FIG. 5 is drawn through
entrance gap 710 the leading edges of which are rounded to prevent
"pickout" of fiber bundles through inadvertent contact of the
moving fabric web with lip of gap 710. The gap is widened along
segments 720, 720a, 722, 722a, 724, and 724a at the points where
the pre-determined bends in the planer fabric web are initiated. To
further aid in the bending and shaping process, the interior fabric
contacting surfaces are tapered through the forming block to
gradually begin gently urging the edges of the fabric web inward to
form folded edges 105 and 104a as the web passes through the
shaping block. The block is made in two halves 712 and 714 which
are joined by screws (not shown) to permit ready access to the
tapered interior surfaces of the block to facilitate minor
adjustment of the contours thereof by filing, sanding, or abrading.
Inserts 726 and 726a, held in place by screws (not shown), permit a
wider range of adjustment of the subtle geometry at gap termini
comprising the fold initiating contact points. The shape, taper,
and finish at these initial contact points necessarily interact
more subtly with fiber bundles at the fabric edge during fold
initiation. Bores 728 are for insertion of mounting bolts shown in
FIG. 6 are included for the sake of completeness.
[0072] FIG. 7B shows the exit side of shaping block 700. Gap 711 is
generally narrower and fold initiating gaps 725 and 725a at gap
termini are bent inward more acutely (angle .beta. is more acute)
consistent with the inventive fold initiation processes occurring
within the shaping block.
[0073] FIGS. 8A and 8B likewise show entrance and exit sides
shaping block 800 used to form the hinged inside corner structural
member shown in FIGS. 3 and 4. Included in the figures are
contoured gaps 810 and 811, widened gap segments 820, 820a, 822,
822a, 824, and 824a ; inserts 826 and 826a ; and angle
.beta.--components of shaping block 800 which cooperate in the
fashion previously described to fold and pre-shape the fabric to
form the interior corner structural member of FIGS. 3 and 4. For
the sake of completeness, block halves 812 and 814 and bores 828
are also shown. Gap 811 is generally narrower and fold initiating
gaps 825 and 825a at gap termini are bent inward more acutely
(angle .beta. is more acute) consistent with the inventive fold
initiation processes occurring within the shaping block.
[0074] The prototype shaping blocks shown in FIGS. 7A, 7B, 8A, 8B
are made of wood. However, shaping blocks made of metal (for
example, steel, aluminum, copper, brass, or bronze) or ceramic are
contemplated as falling within the scope of the present invention.
The choice of material for the blocks is somewhat dependent upon
the mechanical properties of the fabric selected. For example, a
fabric comprising ceramic fibers may require use of ceramic shaping
block.
[0075] The following description applies to profiles which combine
a single thermoplastic material with the fabric to form the
composite. The flow of fabric through the co-extrusion die is
typically at an angle to the lineal axis of the extruder, typically
at an angle of 90 degrees to the lineal axis of extrusion. Fabric
enters a pre-forming area where the fabric is folded and shaped
prior to the addition of thermoplastic material. The fabric then
enters the extrusion die. The extruder uses standard thermoplastic
materials as used in thermoplastic extrusion. These materials are
melted and forced into the die under pressure. The pressures upon
entering the tool can vary from 1500 to 8000 psi depending upon the
thermoplastic used. For the PVC compounds typically used in
experiments, the material was PVC with pressures ranging from 3800
to 5600 psi, and normally measuring 4200 psi upon gate entry. The
melted thermoplastic flows through a runner system and into the
various segments of the die which are arranged to form the
pre-determined profile shape. It is in this area where the
thermoplastic and fabric come into intimate contact under high
pressure. It has been found that the pressure must be sufficiently
high to initiate pore-filling Darcy flows described hereinabove or
the composite formed will not have adequate adhesion between the
layers, which can result in poor physical properties (shrink, CTE
and elastic modulus) and delamination. As the thermoplastic begins
to solidify and the composite exits the die a standard extrusion
puller is programmed to maintain the required degree of tension on
the fabric. After exit from the extrusion die, the composite member
enters a vacuum calibrator system. The purpose of the calibrator is
to impart the proper finish and maintain the shape of the member
during cooling. The calibrator can be totally or partially immersed
in water or air cooled. As the member is pulled through the
calibrator, the composite cools and contracts to assume its
pre-determined geometry. The above description also applies to
extruding two thermoplastics and fabric. Two extruders inject
thermoplastic from opposite side of the die and the runner system
determines which side(s) of the member the various materials are
applied to in forming the composite. Additional extruders may be
added in a similar fashion as warranted by the geometry of the
member being extruded. The following example structural members
were co-extruded to further illustrate embodiments of the invention
disclosed in detail hereinabove. The following information
illustrates the typical production conditions and compositions and
properties of a structural member made from the resin and
fabric.
[0076] Sample Preparation
[0077] A laboratory scale single screw, 21:1 (L/D) ratio,
Davis-Standard extruders are used to prepare samples of the resin
fabric composite (Fiber-mat). The resin and flexible polymer are
combined in the extruder head with fabric (11 to 19% of fabric by
weight based on fabric plus resin). The resin used is GEON 427
series, and the flexible polymer used is GEON E2001 or GEON 83794,
which are available from GEON Company; Cleveland Ohio 44131. To
assist processability an additive package is added at 1.5-2 phr
(parts per hundred parts of resin) to the resin feed. The additive
package includes heat stabilizer and lubricants. More specifically
the additives include: optionally 15 parts titanium dioxide, about
2 parts ethylene bis-stearamide wax, about 1.5 parts calcium
stearate, optionally about 7.5 parts Rohm & Haas 820-T acrylic
resin impact modifier/process aid, and about 2 parts of dimethyl
tin thioglycolate. The resin blend and flexible polymer are fed to
their respective extruders using volumetric or more preferably
loss-in-weight feeders. Feed rates are adjusted to provide a
smooth, continuous flow of materials within the co-extrusion head
and pressurized deposition thereof onto pre-determined regions of
the fabric.
[0078] The extruders are run at the following conditions:
3 SETTING PARAMETER RESIN BLEND FLEX. POLYMER Barrel Zone 1 Temp.
190.degrees. C. 120 degrees C. Barrel Zone 2 Temp. 190.degrees. C.
120 degrees C. Barrel Zone 2 Temp. 190.degrees. C. 120 degrees C.
Adapter Temp. 190.degrees. C. 115 degrees C. Die Temp. 187.degrees.
C. 187 degrees C. Screw Speed 25 RPM 3 RPM Puller Rate 4 feet per
min. 4 feet per min.
[0079] The temperatures, feed rates and the screw speeds are
adjusted to accommodate the varying flow characteristics of
different polymers. During extrusion, about 4 foot test strips were
saved for physical property testing. The resulting PVC/glass fabric
hinged profiles had widths of 4-10 inches and the extruded material
was cut into pieces of 1 by 12 inches. The material had a single
layer of glass fabric with a PVC coating. This material was tested
for properties useful in fenestration applications and other
applications.
[0080] Shrink Rate
[0081] Shrink is the difference between a thermoplastics' original
length to the length obtained after thermally shocking the part.
The test procedure is as follows: An approximately 12 inch test
coupon is cut from a structural member and a ten inch line is
scored thereon. It is placed (unsupported) into a water bath at the
boiling point of water (at the test location, this is 205.degree.
F.) for five minutes so that the entire coupon is thermally
saturated at 205.degree. F. It is removed from the bath and
immediately placed into another water bath at 70.degree. F. The
length between the lines is measured and difference in length
recorded as a percentage change from the original length.
[0082] The above quantity is important in the construction industry
because as dark surfaces heat, they may reach temperatures which
exceed the heat deflection temperatures of the materials by solar
radiation and then cool. These thermal cycles can eventually stress
relieve structural members thus distorting a fenestration product
formed therefrom. Geon Fiberloc.RTM. and GE Valox.RTM. 508
materials were tested for shrink. Both materials are thermoplastic
resins with a fiber fill. A proprietary blend of PVC was also
tested along with the Fiber-mat composite. Results are summarized
below.
4 Fiber-Mat Material Fiberloc .RTM. Valox .RTM. PVC Composite
Shrink (%) 0.38 0.08 2.3 0.21
[0083] The new Fiber-mat composite material has shrink rate
comparable to the thermoplastic, and is a substantial improvement
over the PVC compounds which is one of the ingredients used in its
construction. Because PVC can be used, the comparative cost is less
than many costly materials which cost 4 to 10 times the cost of
this composite.
[0084] Coefficient of Thermal Expansion (CTE)
[0085] Tests per ASTM D696
[0086] Coefficient of thermal expansion is the amount the material
changes in length per unit length per unit temperature. It does not
include the shrink rate effects shown above. Thus when a material
is heated and then cooled, it returns to its original length. This
quantity is important in design of construction components. Parts
using dissimilar materials must not bind, twist or bow as
temperatures change or fit, form or function may be affected. Below
is a comparison of some typical construction materials used in
fenestration products.
5 Wood (Ponderosa Pine Fiber-Mat Material PVC Powders lengthwise)
ABS Resins Aluminum Composite CTE 3.4-4.0 .times. 10.sup.-5 0.3
.times. 10.sup.-5 4-7.7 .times. 10.sup.-5 1.33 .times. 10.sup.-5
1.7 .times. 10.sup.-5 (in/in/.degree. F.)
[0087] Wood and aluminum represent very common fenestration
materials. The Fiber-mat composite is more compatible with these
materials than either PVC or the ABS based thermoplastics with or
without glass fill, PVC or other resins, which have CTE's about two
to four times that of the composite. Large differences in CTE can
lead to unintentional exposure as one material contracts past the
other, increased stresses between parts which may result in
cracking, distortion or failure of adhesives between layers of
differing materials or failure of assemblies which may lead to
other forms of mechanical failure. The improvement of CTE
compatibility of wood or aluminum with the composite helps in
reducing problems which can be associated with large differences in
CTE.
[0088] Thermal Cycling
[0089] Test coupons were cycled in an immersion air chamber between
180.degree. F. and -20.degree. F. three times daily. Observed
distortion of thermal cycled parts was minimal. Standard PVC parts
of the same configuration will shrink, warp, bow and twist.
Observations made using thermal cycle tests agree with the data,
observations and analysis described above.
[0090] Impact
[0091] Test method ASTM D256
6 PVC Wood (high (Ponderosa Pine Fiber-Mat Material impact)
lengthwise) ABS Resins Composite Impact 10-30 N/A 1-8 10-30
(ft-lb./inch-notch)
[0092]
7 Mechanical Wood Property PVC (Ponderosa Pine Fiber-Mat (ASTM
D790) Powders lengthwise) ABS Resins Composite Modulus of 300 997
1500 830 Elasticity (KPSI) Modulus of 6.4 5.1 27 14 Rupture (KPSI)
Elongation at N/A 2 2.8 Yield (%)
[0093] Typical test data have a standard deviations lying within
12% of their mean values, which show the thermoplastic/glass fabric
composite of the invention to be a superior material in
applications such as building components especially fenestration
units.
[0094] The above specification test data and examples provide a
basis for understanding the means and bounds of the invention,
however, the invention can have many embodiments which do not
depart from the spirit and scope of the invention. The invention is
embodied in the Claims hereinafter appended.
* * * * *