U.S. patent application number 11/247688 was filed with the patent office on 2007-04-12 for fiber size, sized reinforcements, and articles reinforced with such reinforcements.
Invention is credited to Jeffrey L. Antle, Donald R. Holman, Robert A. Schweizer, David L. Shipp.
Application Number | 20070082199 11/247688 |
Document ID | / |
Family ID | 37762334 |
Filed Date | 2007-04-12 |
United States Patent
Application |
20070082199 |
Kind Code |
A1 |
Schweizer; Robert A. ; et
al. |
April 12, 2007 |
Fiber size, sized reinforcements, and articles reinforced with such
reinforcements
Abstract
The present invention relates to fiber-size compositions for
coating glass or other reinforcing fiber materials that are used in
the manufacturing of composites. The fiber-size composition
contains at least about 4% by weight of a polyvinylpyrrolidone film
former, at least one lubricant and a coupling agent. The sizing
composition gives the fibers desirable properties such as high
strength, improved flexibility, fuzz formation resistance, and
fiber smoothness and softness.
Inventors: |
Schweizer; Robert A.;
(Granville, OH) ; Antle; Jeffrey L.; (Amarillo,
TX) ; Holman; Donald R.; (Amarillo, TX) ;
Shipp; David L.; (Heath, OH) |
Correspondence
Address: |
OWENS CORNING
2790 COLUMBUS ROAD
GRANVILLE
OH
43023
US
|
Family ID: |
37762334 |
Appl. No.: |
11/247688 |
Filed: |
October 11, 2005 |
Current U.S.
Class: |
428/375 |
Current CPC
Class: |
D06M 15/3562 20130101;
D06M 15/564 20130101; C08J 2377/00 20130101; D06M 15/53 20130101;
Y10T 428/2933 20150115; D06M 15/61 20130101; C03C 25/26 20130101;
D06M 2200/40 20130101; C08J 5/08 20130101; C08L 75/04 20130101 |
Class at
Publication: |
428/375 |
International
Class: |
D02G 3/00 20060101
D02G003/00 |
Claims
1. A fiber-size composition comprising: at least about 4% by weight
of a polyvinylpyrrolidone film former having a molecular weight in
the range of about 10,000 to about 70,000; at least one lubricant;
and a coupling agent.
2. The fiber-size composition according to claim 1 wherein said
lubricant is polyethylene glycol.
3. (canceled)
4. The fiber-size composition of claim 1 further comprising a
polyethyleneimine polyamide salt lubricant
5. The fiber-size composition of claim 1 wherein said coupling
agent is a silane coupling agent.
6. A fiber-size composition comprising: at least about 4% by weight
of a polyvinylpyrrolidone film former at least one lubricant: a
coupling agent, and further comprising a polyurethane.
7. A fiber-size composition comprising: from about 1.0% to about
3.0 by weight of a silane coupling agent; from about 4.0% to about
7.0% by weight of a polyvinylpyrrolidone film-former; from about
1.0% to about 4.0% by weight of a polyurethane film-former, from
about 2.0% to about 3.5% by weight of a polyethylene glycol
lubricant; from about 0.45% to about 0.70% by weight of a
polyethyleneimine polyamide salt lubricant; from about 0.3% to
about 0.6% by weight of an acetic acid; and the remainder water,
the sum of the fiber-size constituents making 100%.
8. A reinforcing fiber coated with the fiber-size composition of
claim 1.
9. The reinforcing fiber of claim 8 wherein said fiber is an
E-glass fiber.
10. A compounding formulation comprising the reinforcing fiber of
claim 8 and a matrix resin.
11. The compounding formulation of claim 10 wherein said matrix
resin is selected from the group consisting of polyolefins,
polyesters, polyacetals, polyamides, polyacrylamides, polyimides,
polyethers, polyvinylethers, polystyrenes, polyoxides,
polycarbonates, polysiloxanes, polysulfones, polyanhydrides,
polyimines, epoxies, polyacrylics, polyvinylesters, polyurethane,
maleic resins, urea resins, melamine resins, phenol resins, furan
resins, polymer blends, polymer alloys, and mixtures thereof.
12. The compounding formulation of claim 10 wherein said matrix
resin is a polyamide.
13. A composite article formed from the compounding formulation of
claim 10.
14. A method of preparing reinforcing fibers comprising: a)
preparing a fiber-size composition comprising: at least about 4% by
weight of a polyvinylpyrrolidone film former having a molecular
weight in the range of about 10,000 to about 70.000; at least one
lubricant; and a coupling agent; b) contacting fibers with said
fiber-size composition; and c) allowing said fiber-size composition
to solidify on said fibers to form said reinforcing fibers.
15. The method of preparing reinforcing fibers according to claim
14 wherein said fibers are glass fibers.
16. A method of preparing reinforcing fibers comprising: a)
preparing a fiber-size composition comprising: at least about 4% by
weight of a polyvinylpyrrolidone film former; at least one
lubricant; and a coupling agent; b) contacting fibers with said
fiber-size composition; and c) allowing said fiber-size composition
to solidify on said fibers to form said reinforcing fibers; wherein
said fiber-size composition further comprises a polyurethane
film-former; and a second lubricant and acetic acid.
17. The method of claim 16 wherein said fiber-size composition
comprises from about 1.0% to about 3.0 by weight of a silane
coupling agent; from about 4.0% to about 7.0% by weight of a
polyvinylpyrrolidone film-former; from about 1.0% to about 4.0% by
weight of a polyurethane film-former; from about 2.1% to about 3.5%
by weight of a polyethylene glycol lubricant; from about 0.45% to
about 0.70% by weight of a polyethyleneimine polyamide salt
lubricant; from about 0.3% to about 0.6% by weight of an acetic
acid; and the remainder water, the sum of the fiber-size
constituents making 100%.
18. The method of preparing reinforcing fibers according to claim
15 wherein said glass fibers are essentially boron-free glass
fibers.
19. A method of preparing a composite formulation comprising the
step of combining said reinforcing fibers prepared according to the
method of claim 14 with a matrix resin to form said composite
formulation.
20. A method of preparing a composite article comprising the step
of forming said composite formulation formed in claim 19 into said
composite article.
Description
TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION
[0001] The present invention relates to fiber-size compositions for
coating glass or other reinforcing fiber materials that are used in
the manufacturing of composites. The sizing composition gives the
fibers desirable properties such as high strength, improved
flexibility, fuzz formation resistance, and fiber smoothness and
softness.
BACKGROUND OF THE INVENTION
[0002] Glass fibers are useful in a variety of technologies. For
example, glass fibers are commonly used as reinforcements in
polymer matrices to form glass fiber reinforced plastics or
composites. Glass fibers have been used in the form of continuous
or chopped filaments, strands, rovings, woven fabrics, nonwoven
fabrics, meshes, and scrims to reinforce polymers. It is known in
the art that glass fiber reinforced polymer composites possess
higher mechanical properties compared to unreinforced polymer
composites, provided that the reinforcement fiber surface is
suitably modified by a sizing composition. Thus, better dimensional
stability, tensile strength and modulus, flexural strength and
modulus, impact resistance, and creep resistance may be achieved
with glass fiber reinforced composites.
[0003] Chopped glass fibers are commonly used as reinforcement
materials in reinforced composites. Conventionally, glass fibers
are formed by attenuating streams of a molten glass material from a
bushing or orifice. The glass fibers may be attenuated by a winder
which collects gathered filaments into a package or by rollers
which pull the fibers before they are collected and chopped. An
aqueous sizing composition, or chemical treatment, is typically
applied to the fibers after they are drawn from the bushing. After
the fibers are treated with the aqueous sizing composition, they
may be dried in a package or chopped strand form.
[0004] Chopped strand segments may be mixed with a polymeric resin
and supplied to a compression- or injection- molding machine to be
formed into glass fiber reinforced composites. Typically, the
chopped strand segments are mixed with pellets of a thermoplastic
polymer resin in an extruder. In one conventional method, polymer
pellets are fed into a first port of a twin screw extruder and the
chopped glass fibers are fed into a second port of the extruder
with the melted polymer to form a fiber/resin mixture.
Alternatively, the polymer pellets and chopped strand segments are
dry mixed and fed together into a single screw extruder where the
resin is melted, the integrity of the glass fiber strands is
destroyed, and the fiber strands are dispersed throughout the
molten resin to form a fiber/resin mixture. Next, the fiber/resin
mixture is degassed and formed into pellets. The dry fiber
strand/resin dispersion pellets are then fed to a molding machine
and formed into molded composite articles that have a substantially
homogeneous dispersion of glass fiber strands throughout the
composite article.
[0005] It has been determined that sizing compositions containing a
high molecular weight film-former, such as a polyvinylpyrrolidone
having a molecular weight of 1.6 million, results in a stiff glass
fiber strand having extremely high fuzz. This is a result of the
film-former forming a brittle film which leads to fiber breakage as
it crosses contact points in the manufacturing operation.
SUMMARY OF THE INVENTION
[0006] The above problems are solved and objects met by the present
invention which features a fiber-size composition comprising a) low
molecular weight polyvinylpyrrolidone, b) a coupling agent, c) one
or more lubricants, and d) optional additives. The fiber-size
composition is typically aqueous based and is water soluble.
[0007] The coupling agent has at least one group that is reactive
with a fiber and a second group that is reactive with the resin
matrix. Both of these groups tend to be hydrophilic and usually
soluble in water. Typically, the coupling agent is a silane.
[0008] Optional additives may be added to the fiber-size
composition, such additives include, but are not limited to wetting
agents, lubricants, surfactants, and antifoam agents. An additional
polyurethane film-former can also be used in the fiber-size
composition to improve the processing characteristics of the size
composition and is also useful in maintaining fiber integrity
during the processing of coated fibers. Polyurethane provides good
adhesion to a variety of matrix resin polymers, is UV stable,
hyrodlytically stable and easily dispersible in aqueous
systems.
[0009] Glass fibers are typically coated with the fiber-size
composition as part of the fiber filament formation process. By
coating the fiber with the size composition early in its formation
stage, the fiber size coating protects the filaments from abrasion
and breakage as the filaments are formed into fibers and wound or
chopped for further processing.
[0010] The fiber-size composition can be applied to all glass
fibers including E-glass (a borosilicate glass) as well as
boron-free fibers. The boron-free fibers can also be essentially
free of moieties such as F.sub.2, TiO.sub.2, SO.sub.3, and
combinations of them. A boron-free glass fiber that can be
advantageously coated with the fiber-size composition of the
present invention. Such boron-free glass fibers are manufactured by
Owens Coming (Toledo, Ohio) under the name ADVANTEX.RTM..
[0011] After the fiber is coated with the fiber-size composition,
it is used as part of a compounding formulation that includes the
size coated (reinforcing) fiber and a matrix resin. The matrix
resin can be selected from a wide variety of plastics including
polyolefins, polyesters, polyacetals, polyamides, polyacrylamides,
polyimides, polyethers, polyvinylethers, polystyrenes, polyoxides,
polycarbonates, polysiloxanes, polysulfones, polyanhydrides,
polyimines, epoxies, polyacrylics, polyvinylesters, polyurethane,
maleic resins, urea resins, melamine resins, phenol resins, furan
resins, polymer blends, polymer alloys and mixtures of them.
[0012] The compounding formulation can also contain one or more
compounding agents such as coupling agents, antioxidants, pigments,
antistats, fillers, flame retardants and other additives.
Preferably the matrix resin is a long-fiber thermoplastic
polyamide.
[0013] The compounding formulation is then typically processed to
form pellets that are then injected molded to form the desired
composite article.
[0014] The present invention also features a method of preparing
reinforcing fibers and then using them to form a composite
article.
[0015] After the fiber-size composition is prepared, it is
contacted with fibers after which the fiber-size composition is
allowed to solidify on the fibers to form the reinforcing fibers
After the reinforcing fibers are prepared they are mixed with a
matrix resin to form a composite formulation. The composite
formulation can also contain coupling agents, antioxidants,
pigments, antistats, fillers, and flame retardants. The composite
formulation is then processed to form a composite article.
[0016] It is an object of the present invention is a sizing
composition useful to prevent fuzzing comprising substantial amount
of a polyvinylpyrrolidone (PVP) film former.
[0017] Another object of the invention is a strand which
incorporates the PVP sizing. The sized strand is preferably made by
the application of the a sizing composition containing PVP to a
plurality of individual fiber filaments which are then gathered
into a strand.
[0018] Another object of the invention are pellets which
incorporate the sizing. The pellets are preferably made by
impregnating the strand with a synthetic resin, cooling to form an
impregnated strand, and chopping the impregnated strand to form the
pellets.
[0019] Yet another object of the invention is a reinforced resin
composite incorporating the sizing. The composite comprises a fiber
reinforcing material dispersed in a synthetic resin matrix. The
mixed is preferably made by directly consolidating the pellets.
[0020] Yet another object of the invention is a fiber-size
composition that is particularly well-suited for use in long-fiber
thermoplastic applications. Fiber-reinforced thermoplastic polymer
structural components are most commonly manufactured from long
fiber thermoplastic (LFT) granulates (pellets), glass mat
thermoplastic (GMT) sheets, or pultruded sections. Long
fiber-reinforced granulates typically consist of glass fiber
bundles encapsulated with a thermoplastic through a cable coating
or a pultrusion process. LFT granulates can be injection molded but
are more commonly extrusion compression molded in order to preserve
fiber length in the finished product.
[0021] The injection-moldable pellets thus contain fully wetted
fibers equal in length to the pellet--typically 1 to 25 mm. This
compares to 0.75 mm to 1.5mm. fiber lengths used in conventional,
short-fiber products. As is well-known, mechanical properties of
long-fiber compounds are improved dramatically over those of the
short-fiber compounds.
[0022] Polymer components reinforced with fibers may also be
manufactured using continuous in-line extrusion methods known in
the art. Such methods involve the plastication of a polymer in a
first single screw extruder from which the output is fed to a
second single screw extruder. Fibers are introduced in the polymer
melt in the second extruder either in chopped-segmented form or as
continuous strands under a predetermined tension. The
fiber-reinforced polymer compound is fed into an accumulator and
then applied automatically or in a separate step to a compression
molding tool wherein the fiber-reinforced polymer compound is
shaped as required for a particular application. Alternatively, the
fiber-reinforced polymer compound may be continuously extruded onto
a conveyor and sectioned thereupon. The conveyor delivers the
sectioned fiber-reinforced polymer compound to a placement assembly
which removes the sectioned compound from the conveyor and places
the compound upon the compression molding tool.
[0023] As used here, the term "size" or "sizing" refers to a
coating that is applied initially to forming filaments of a fiber
for the purpose of protecting the fiber from abrasion breakage of
the fibers during further processing of the fibers and subsequently
promoting the adhesion between the fibers and the materials which
they reinforce. While some physical binding between filaments may
occur when the filaments are bundled into threads, it is essential
that the sizing not interfere with the dispersion of the fibers in
the matrix into which h the fibers are incorporated. That is, the
sizing should not have a tendency to agglomerate the threads,
especially when incorporated into a matrix composition. This is in
contrast to a "binder" where the formulation promotes the binding
of threads to each other at their intersection (crossing points) in
such forms as mats, fabrics and nonwovens through the
polymerization of the binder while it is in contact with the
fibers. One of the purposes of a size is to coat the entire
filament in order to protect the filaments and fibers during
initial formation of the filaments and fibers and in their
subsequent processing.
[0024] In a size, the emphasis is on bond formation between
moieties already existing on components in the size composition and
moieties found on the glass and between moieties found on
components in the size composition and moieties found in the matrix
resin typically with minimal polymerization of the components found
in the size composition. A size typically solidifies on the fiber
principally as a result of physical water removal whereas a binder
is designed for a chemical (typically polymerization) reaction that
gives a stronger fiber to fiber binding.
[0025] The foregoing and other objects, features and advantages of
the invention will become apparent from the following disclosure in
which one or more preferred embodiments of the invention are
described in detail. It is contemplated that variations in
procedures may appear to a person skilled in the art without
departing from the scope of or sacrificing any of the advantages of
the invention.
DETAILED DESCRIPTION AND EMBODIMENTS OF THE INVENTION
[0026] The present invention comprises a fiber-size composition
having at least about 4% by weight of a polyvinylpyrrolidone (PVP)
film former, at least one lubricant, and a coupling agent that
improves the sizing reinforced fiber materials used in the
manufacture of fiber-reinforced composites. The fiber-size
composition provides improved short-term mechanical performance of
fiber-reinforced composites such as increased strength and reduced
fuzzing of the strand. Optionally, the fiber-size composition may
also contain an additional polyurethane film former and
conventional additives such as wetting agents, pH adjusters, etc.
The fiber-size composition provides improved long-term mechanical
performance of the composite such as increased resistance to creep
and fatigue.
[0027] The PVP film former is a low molecular weight film former
having a molecular weight in the range of about 10,000 to about
70,000. Use of a low molecular weight film former results if a more
flexible coating on the glass fiber strand. Typical PVP film
formers include K15 and K30 film formers available from ISP
International, Wayne, N.J. The fiber size composition includes at
least about 4% by weight of the PVP film former, typically between
about 4% to about 7% by weight based on the sum of fiber size
constituents making 100%. Using a substantial amount of PVP film
former results in many improved properties of the glass fiber
strand.
[0028] A wide variety of coupling agents are known in the art most
of which most are silicon-based "silane" coupling agents. The
typical coupling agent is a silane represented by the formula
X.sub.n--Si--Y.sub.4-n, where X is an acid reactive group and Y is
a fiber reactive group, and n is preferably 1 but may be 2 or 3.
Typically Y is an alkoxy that is hydrolyzed to a hydroxyl group in
the fiber-size composition. X is typically an alkyl amino group but
other functional groups are commercially available. Aminosilanes
are commercially available from OSi Specialties, Inc., located in
Tarrytown, N.Y., United States of America, Dow Corning, Inc.
located in Midland, Mich., United States of America, or
Degussa-Huls AG located in Frankfurt, Germany. A preferred amino
silane coupling agent is gamma-aminopropyltriethoxysilane
commercially available under the trade name A-1110 from OSi
Specialties, Inc.
[0029] The coupling agent is generally included in the fiber-size
composition at a concentration of about 1.0% to about 15% by
weight. Preferably, the coupling agent is used in an amount of from
about 0.25% to about 7.0 percent by weight. Most preferably, the
amount is between about 0.5% to about 2.0% by weight.
[0030] Lubricants which may be used include lower molecular weight
polyethylene glycol (PEG) lubricants such as those sold under the
tradenames, PEG 400MO (polyethylene glycol monostearate) and PEG
200MO (polyethylene glycol monostearate). Amounts of PEG lubricants
present in the fiber-size composition range from about 2.0% to
about 3.5% by weight.
[0031] An additional lubricant may be added to the fiber-sizing
composition such as a polyethyleneimine polyamide salt lubricant.
Such a lubricant is EMERLUBE 6760 (available from Emery Corp.). The
additional lubricant is present in the fiber-size composition in an
amount of from about 0.45% to about 0.70% by weight.
[0032] Optionally, an additional polyurethane film former is
present in the fiber-size composition. Such a polyurethane film
former is sold under the name HYDROSIZE U6-03 manufactured by
Hydrosize Technologies, Raleigh, N.C. The polyurethane film former
is present in the fiber-size composition in an amount of from about
1.0% to about 4.0% by weight.
[0033] In particular, it is preferred that pH of the size
composition generally fall within a pH range of between about 4 to
about 6.5. However the pH of the size composition may be adjusted
to facilitate the compatibility of the fiber-size ingredients
through the addition of one or more pH adjusters. For example,
small amounts of a weak acid, such as acetic acid, may be added to
the fiber-size to adjust the pH. Acetic acid may be present in the
size composition in an amount from about 0.3% to about 0.6% by
weight.
[0034] The fiber-size composition of the present invention includes
a silane coupling agent present in the amount of from about 1.0% to
about 3.0% by weight; a PVP film-former present in an amount of
from about 4.0% to about 7.0% by weight; a PEG lubricant present in
an amount of from about 2.0% to about 3.5% by weight; a
polyethyleneimine polyamide salt lubricant present in an amount of
from about 0.45% to about 0.70% by weight; acetic acid present in
an amount of from about 0.3% to about 0.6% by weight; and the
remainder water, the sum of the fiber-size constituents making
100%.
[0035] An alternative fiber-size composition includes a silane
coupling agent present in the amount of from about 1.0% to about
3.0% by weight; a PVP film-former present in an amount of from
about 4.0% to about 7.0% by weight; a polyurethane film-former
present in an amount of from about 1.0% to about 4.0% by weight; a
PEG lubricant present in an amount of from about 2.0% to about 3.5%
by weight; a polyethyleneimine polyamide salt lubricant present in
an amount of from about 0.45% to about 0.70% by weight; acetic acid
present in an amount of from about 0.3% to about 0.6% by weight;
and the remainder water, the sum of the fiber-size constituents
making 100%.
[0036] It is often necessary to include one or more additives
useful to improve fiber wettability, component dispersion, and ease
of processing of the fiber-size composition Optionally, the
fiber-size composition may include conventional additives such as
wetting agents, antioxidants, antifoaming agents, processing aids,
antistatic agents, and non-ionic surfactants.
[0037] The fiber-size composition may be prepared by combining the
ingredients thereof according to any method known to one of
ordinary skill in the art. Preferably, the fiber-size composition
may be made by blending the individual components of the fiber-size
composition with a diluent to form a solution or suspension. Most
preferably, the diluent is water.
[0038] The sequence of combining the ingredients is not critical to
forming a stable fiber-size composition. The following is
illustrative of a procedure has been found to give a fiber-size
composition that can be applied to glass fiber filaments with good
results The components, composition as a stable dispersion having a
storage stability of up to about 72 hours at temperatures of from
about 10.degree. C. to about 32.degree. C. Although pH of the
fiber-size composition is not critical, it is preferred that the
final fiber-size composition formed by combining all the
aforementioned ingredients having a pH in the range of from about 4
to about 6.5.
[0039] The fiber-size composition of the present invention may be
applied to the reinforcing fiber material by any suitable method to
form a coated reinforcing fiber material. The reinforcing fiber
material to which the fiber-size composition of the present
invention can be applied may be selected from any reinforcing fiber
materials known in the art such as glass fibers, polymer fibers,
carbon or graphite fibers, natural fibers and any combination
thereof. Preferably, glass fibers are used including soda lime
glasses, borosilicate glasses such as E-glass, high-strength
glasses such as S-glass, and E-type glasses with lower amounts of
boron or boron-free glasses. In addition to boron, such glasses may
also be free of moieties such as F.sub.2, TiO.sub.2, and SO.sub.3
and their combinations. As used here, the term "boron/fluorine
free" refers to glasses with low amounts or none of these two
elements.
[0040] The reinforcing fiber material may be in the form of
individual filaments, twisted yams, strands or rovings. The sized
reinforcing fiber material may be used in continuous or
discontinuous form in the manufacture of fiber-reinforced
composites. The term "continuous" as used herein with regard to the
reinforcing fiber material is intended to include reinforcing fiber
materials that are in the form of unbroken filaments, threads,
strands, yams or rovings and which may either be sized directly
after formation in a continuous fiber-forming operation or which
may be formed and wound into packages that can be unwound at a
later time to allow application of the fiber-size composition. The
term "discontinuous" as used herein with regard to the reinforcing
fiber material is intended to include reinforcing fiber materials
that have been segmented by chopping or cutting or which are formed
from a process designed to form segmented fibers such as a
fiber-forming spinner process. The segments of discontinuous
reinforcing fiber material that are used in the present invention
may vary in length, ranging from about 1 mm to about 25 mm in
length.
[0041] Accordingly, the fiber-size composition may be applied, for
example, to continuous filaments of a reinforcing fiber material
immediately after they are formed in an in-line operation, that is,
as part of the filament formation process. Alternatively, the
fiber-size composition may be applied off-line to unwound strands
of reinforcing fiber material that were previously formed and
packaged. Also the strands may be cut or chopped in an off-line
process. Means for applying the fiber-size composition include, but
are not limited to, pads, sprayers, rollers or immersion baths,
which allow a substantial amount of the surfaces of the filaments
of the reinforcing fiber material to be wetted with the fiber-size
composition.
[0042] Preferably, the fiber-size composition is applied to a
plurality of continuously forming filaments of a reinforcing fiber
material as soon as they are formed from a fiber-forming apparatus
such as a bushing. The bushing is preferably equipped with small
apertures to allow passage of thin streams of a molten reinforcing
fiber material. As the streams of molten material emerge from the
bushing apertures, each stream is attenuated and pulled downward to
form a long, continuous filament. After the filament formation
process which includes the application of the fiber-size
composition, the continuously forming filaments may then be
gathered into strands and chopped or cut in an in-line operation,
or they may be gathered into strands for winding into forming
packages or doffs after which they may be optionally chopped in an
off-line operation. The chopped strands or the forming packages are
then dried. Typically, chopped strands are dried in an oven using a
temperature ranging from about 50.degree. C. to about 300.degree.
C. Typically, forming packages are dried, for example, in a static
oven for a period of about 3 hours to about 30 hours at a
temperature of about 100-150.degree. C. after which they are ready
for use in composite-making operations. Of course, other drying
techniques can be used. The glass-fiber composition is typically
applied to the fiber in an amount to give about 0.01 to about 7.0
wt % dry solids, preferably in an amount of 0.03 to about 6 wt %
dry solids and most preferably in an amount of about 0.1 to about 5
wt % dry solids based on the total weight of dry solids of the
fiber-size composition and the glass fibers.
[0043] The resulting sized reinforcing fiber material may be
utilized to form a composite material. Suitable matrix resins for
this purpose may be thermoplastic polymers, thermoset polymers,
solution processable polymers, aqueous based polymers, monomers,
oligomers, and polymers curable by air, heat, light, x-rays, gamma
rays, microwave radiation, dielectric heating, UV radiation,
infrared radiation, corona discharge, electron beams, and other
similar forms of electromagnetic radiation. Suitable matrix resins
include, but are not limited to, polyolefins, modified polyolefins,
saturated or unsaturated polyesters, polyacetals, polyamides,
polyacrylamides, polyimides, polyethers, polyvinylethers,
polystyrenes, polyoxides, polycarbonates, polysiloxanes,
polysulfones, polyanhydrides, polyiminesepoxies, polyacrylics,
polyvinylesters, polyurethanes, maleic resins, urea resins,
melamine resins, phenol resins, furan resins polymer blends,
polymer alloys and their mixtures.
[0044] The composite formulation may also include one or more
conventionally known additives such as coupling agents,
compatibilizers, flame retardants, pigments, antioxidants,
lubricants, antistats and fillers. Typically, additives are applied
in amounts of from 0.1 wt percent to 10 wt percent of the total
weight of sized reinforcing fiber and matrix resin, preferably 0.2
wt percent to 7.5 wt percent, and most preferred from 0.25 wt
percent to about 5 wt percent.
[0045] The process of compounding and molding the sized reinforcing
fiber material and the matrix resin to form a composite may be
accomplished by any means conventionally known in the art. Such
compounding and molding means include, but are not limited to,
extrusion, wire coating, blow molding, compression molding,
injection molding, extrusion-compression molding,
extrusion-injection-compression molding, long fiber injection, and
pushtrusion. In a preferred embodiment of the present invention,
the chopped fiber strand is coated with the fiber-size composition
and is extruded with a polyamide resin matrix to form pellets.
These chopped pellets then are suitably injection molded into a
desired composite article.
[0046] The amount of matrix resin included in the composite is
generally about 10% to about 99% by weight, based on the total
weight of the composite formulation. Preferably, the percent
composition of matrix resin is between about 30% and about 95% by
weight. Most preferable is about 60% to about 90% by weight, based
on the total weight of the composite.
[0047] The fiber-size composition of the present invention provides
a coating on the reinforcing fibers that improves compatibility and
adhesion with the resin matrix, and results in composites with more
desirable properties such as higher short-term and long-term
mechanical properties.
[0048] The invention illustratively disclosed herein may be
practiced in the absence of any element that is not specifically
disclosed herein. The following examples are representative, but
are in no way limiting as to the scope of this invention.
EXAMPLES
[0049] The size composition components according to embodiments of
the present invention are set forth in Tables 1-5. TABLE-US-00001
TABLE 1 % by Lbs./100 Actual Solids weight gallon of % Active as as
Total Size on Material Solids.sup.(a) received received the Glass
A1100 Silane.sup.(b) 58.000 1.210 10.079 0.04 PVP K15.sup.(c)
100.000 5.065 42.191 0.32 Peg 400M0.sup.(d) 100.000 2.171 18.084
0.14 Emery 6760L.sup.(e) 12.500 0.499 4.157 0.0039 Acetic Acid
100.000 0.330 2.749 D.M. Water 0.000 90.725 755.739 0.50 = Total
solids % .sup.(a)% Active Solids used to calculate predicted size
mix solids. .sup.(b)A-1100 is an amino-propyl-triethoxy-silane
coupling agent. .sup.(c)PVP K15 is a low molecular weight
polyvinylpyrrolidone film former .sup.(d)PEG 400MO is a low
molecular weight polyethylene glycol lubricant .sup.(e)Emery 6760L
is a polyethyleneimine polyamide salt lubricant
[0050] TABLE-US-00002 TABLE 2 % by Lbs./100 Actual Solids weight
gallon of % Active as as Total Size on Material Solids.sup.(a)
received received the Glass A1100 Silane.sup.(b) 58.000 1.452
12.095 0.05 PVP K15.sup.(c) 100.000 6.078 50.630 0.38 Peg
400M0.sup.(d) 100.000 2.605 21.700 0.16 Emery 6760L.sup.(e) 12.500
0.599 4.990 0.0047 Acetic Acid 100.000 0.396 3.299 D.M. Water 0.000
88.870 740.287 0.60 = Total solids % .sup.(a)% Active Solids used
to calculate predicted size mix solids. .sup.(b)A-1100 is an
amino-propyl-triethoxy-silane coupling agent. .sup.(c)PVP K15 is a
low molecular weight polyvinylpyrrolidone film former .sup.(d)PEG
400MO is a low molecular weight polyethylene glycol lubricant
.sup.(e)Emery 6760L is a polyethyleneimine polyamide salt
lubricant
[0051] TABLE-US-00003 TABLE 3 % by Lbs./100 Actual Solids weight
gallon of % Active as as Total Size on Material Solids.sup.(a)
received received the Glass A1100 Silane.sup.(b) 58.000 1.694 14.11
0.06 PVP K15.sup.(c) 100.000 7.091 59.068 0.44 Peg 400M0.sup.(d)
100.000 3.039 25.315 0.19 Emery 6760L.sup.(e) 12.500 0.699 5.823
0.0055 Acetic Acid 100.000 0.462 3.848 D.M. Water 0.000 87.015
724.835 0.70 = Total solids % .sup.(a)% Active Solids used to
calculate predicted size mix solids. .sup.(b)A-1100 is an
amino-propyl-triethoxy-silane coupling agent. .sup.(c)PVP K15 is a
low molecular weight polyvinylpyrrolidone film former .sup.(d)PEG
400MO is a low molecular weight polyethylene glycol lubricant
.sup.(e)Emery 6760L is a polyethyleneimine polyamide salt
lubricant
[0052] TABLE-US-00004 TABLE 4 % Lbs./100 Actual Solids by weight
gallon of % Active as as Total Size on Material Solids.sup.(a)
received received the Glass A1100 Silane.sup.(b) 58.000 1.210
10.079 0.04 PVP K15.sup.(c) 100.000 4.559 37.976 0.28 Hydrosize
U6-03.sup.(d) 30.000 1.69 14.061 0.03 Peg 400M0 (100).sup.(e)
100.00 2.171 18.084 0.14 Emery 6760L.sup.(f) 12.500 0.499 4.157
0.0039 Acetic Acid 100.000 0.330 2.749 D.M. Water 0.000 89.543
745.893 0.50 = Total solids % .sup.(a)% Active Solids used to
calculate predicted size mix solids. .sup.(b)A-1100 is an
amino-propyl-triethoxy-silane coupling agent. .sup.(c)PVP K15 is a
low molecular weight polyvinylpyrrolidone film former
.sup.(d)Hydrosize U6-03 is a polyurethane film former .sup.(e)PEG
400MO is a low molecular weight polyethylene glycol lubricant
.sup.(f)Emery 6760L is a polyethyleneimine polyamide salt
lubricant
[0053] TABLE-US-00005 TABLE 5 % Lbs./100 Actual Solids by weight
gallon of % Active as as Total Size on Material Solids.sup.(a)
received received the Glass A1100 Silane.sup.(b) 58.000 1.210
10.079 0.04 PVP K15.sup.(c) 100.000 4.052 33.752 0.25 Hydrosize
U6-03.sup.(d) 30.000 3.38 28.130 0.06 Peg 400M0 (100).sup.(e)
100.00 2.171 18.084 0.14 Emery 6760L.sup.(f) 12.500 0.499 4.157
0.0039 Acetic Acid 100.000 0.330 2.749 D.M. Water 0.000 88.361
736.047 0.50 = Total solids % .sup.(a)% Active Solids used to
calculate predicted size mix solids. .sup.(b)A-1100 is an
amino-propyl-triethoxy-silane coupling agent. .sup.(c)PVP K15 is a
low molecular weight polyvinylpyrrolidone film former
.sup.(d)Hydrosize U6-03 is a polyurethane film former .sup.(e)PEG
400MO is a low molecular weight polyethylene glycol lubricant
.sup.(f)Emery 6760L is a polyethyleneimine polyamide salt
lubricant
[0054] Table 6 presents the results of tests conducted on
composites formed using Sample 1 and Comparative Samples A and B
using a polyamide 6 matrix resin. A direct long fiber processes,
pushtrusion, was used. TABLE-US-00006 TABLE 6 Sample Comp. Comp. 1
Sample A Sample B Tensile Stress (psi .times. 10.sup.3) 21.31 19.51
18.83 Youngs Modulus (psi .times. 10.sup.6) 1.58 1.17 1.14 Tensile
Elongation (%) 1.90 1.98 1.97 Flex Stress (psi .times. 10.sup.3)
33.67 33.43 31.93 Youngs Modulus (psi .times. 10.sup.6) 1.07 0.87
0.85 Modulus 10-40% (psi .times. 10.sup.6) 0.195 0.230 0.219
Displacement at Yield (inches) 0.195 0.230 0.219 Thickness (inches)
0.120 0.121 0.120 IZOD Unotched (ft-lbs) 11.84 16.37 13.98 LOI (%)
72.33 72.47 73.16 Glass content (%) 28 28 27
[0055] Table 7 presents the results of tests conducted on
composites formed using Sample 2 and Comparative Samples C and D
using a polyamide 6,6 matrix resin. A direct long fiber processes,
pushtrusion, was used. TABLE-US-00007 TABLE 7 Sample Comp. Comp. 2
Sample C Sample D Tensile Stress (psi .times. 10.sup.3) 21.45 20.44
20.56 Youngs Modulus (psi .times. 10.sup.6) 1.42 1.20 1.18 Tensile
Elongation (%) 1.92 2.07 2.11 Flex Stress (psi .times. 10.sup.3)
35.76 34.68 34.79 Youngs Modulus (psi .times. 10.sup.6) 1.21 0.95
0.93 Modulus 10-40% (psi .times. 10.sup.6) 0.181 0.212 0.216
Displacement at Yield (inches) 0.181 0.212 0.216 Thickness (inches)
0.119 0.121 0.121 IZOD Unotched (ft-lbs) 10.13 13.20 14.38 LOI (%)
73.43 73.64 73.33 Glass content (%) 27 26 27
[0056] Table 8 presents the results of tests conducted on
composites formed using Sample 3 and Comparative Samples E and F
using a polyamide 6,6 matrix resin. Long fiber pellets were tested.
TABLE-US-00008 TABLE 8 Sample Comp. Comp. 3 Sample E Sample F
Tensile Stress (psi .times. 10.sup.3) 37.28 34.55 Youngs Modulus
(psi .times. 10.sup.6) 2.79 2.74 Tensile Elongation (%) 2.00 1.90
Flex Stress (psi .times. 10.sup.3) 57.48 55.92 Youngs Modulus (psi
.times. 10.sup.6) 2.23 2.37 Modulus 10-40% (psi .times. 10.sup.6)
0.164 2.35 Displacement at Yield (inches) 0.164 0.164 Thickness
(inches) 0.120 0.164 IZOD Unotched (ft-lbs) 26.60 25.26 LOI (%)
49.84 48.58 Glass content (%) 50 51
The invention of this application has been described above both
generically and with regard to specific embodiments. Although the
invention has been set forth in what is believed to be the
preferred embodiments, a wide variety of alternatives known to
those of skill in the art can be selected within the generic
disclosure. The invention is not otherwise limited, except for the
recitation of the claims set forth below.
* * * * *