Fiber reinforced thermoplastic structural member

In the manufacture of a structural member comprising a thermoplastic composite core with an exterior reinforcing layer, the core member is initially extruded in the shape of a profile. The profile is then contacted with reinforcing fiber and resin to form the exterior reinforcing layer. The exterior thermosetting layer is cured to form a reinforcing layer. The structural member is preferably manufactured using a pultrusion method in which a tractor device is used to provide linear movement of the profile from the extrusion head to the exterior coating operation. The fiber-reinforced thermoset is coated on the entirety of the exterior of the profile or is applied only on a portion of the profile requiring reinforcement in a defined load-bearing direction. The preferred thermoplastic core comprises a polymer-fiber composite material. Such a structural member has significantly improved Young's modulus providing strength for applications such as telephone poles, electric poles, electric lighting poles, boat mast or keel applications, lumber replacements, structural members used in window and door manufacture, etc.

FIELD OF THE INVENTION 
The invention relates to shaped (non-circular) fiber-reinforced structural 
members. More particularly, the invention relates to fiber-reinforced 
structural members having an exterior fiber-reinforced thermoset layer 
formed on a thermoplastic profile. Such reinforced profiles have a variety 
of useful cross-sectional shapes having acceptable mechanical strength for 
high structural loading. The invention also relates to a pultrusion method 
of forming such a structural member involving an extrusion die for the 
formation of a thermoplastic profile comprising a thermoplastic composite. 
The process further involves forming an uncured layer of fiber and 
thermosetting resin on the profile exterior which can be cured to form the 
reinforced structural member. The useful shapes of the profile can be 
complex for specific application in window/door manufacture, automotive, 
aviation, I. beam and C-channel, and other applications as structural 
members. Further, the invention also relates to structural units using the 
fiber-reinforced structural member for increased strength. 
BACKGROUND OF THE INVENTION 
A great deal of attention has been directed to the fabrication or 
manufacture of structural members that can withstand substantial 
structural loads and varying temperatures arising in the natural 
environment. In certain arid desert areas, average daily temperatures can 
reach 100.degree. F. or more. Most common structural members comprise a 
support structure using either metallic structures manufactured from 
aluminum, steel, stainless steel metallic fiber or other high strength 
metallic material. Further, large structural wooden members have been used 
in utility poles, bridge components, housing structures and other similar 
units. Such wooden and metallic structural members have had some 
substantial success. 
Increasing attention has also been given to the manufacture of structural 
members from thermosetting and thermoplastic materials. Processing these 
materials offers improved manufacturing properties because of the ease of 
processing thermosetting and thermoplastic resins and combining those 
materials with reinforcing fibers. 
Karino et al., U.S. Pat. No. 4,515,737 teach a process for producing a 
composite circular composite pipe. In the process, a thermoplastic resin 
pipe is formed using an extruder. The surface of the pipe is covered with 
a uniform layer comprising continuous fibrous reinforcing material 
impregnated with a thermosetting resin in its axial direction by a draw 
molding method, helically winding a continuous fibrous reinforcing 
material impregnated or not impregnated with a thermosetting resin 
uniformly on the initial resin fibrous reinforced layer. The Karino et al. 
material has a polyvinyl chloride pipe center and a first and second 
fibrous reinforcing layer. This process, using a wrapped layer, cannot be 
used for complex profile shapes. 
Tanaka et al., U.S. Pat. No. 4,740,405 teach an extruded profile or frame 
member comprising a thermoplastic resin having reinforcing wires 
throughout the frame member joined using a thermosetting resin. The fibers 
are typically dispersed within the profile material. 
Balazek et al., U.S. Pat. No. 4,938,823 teach a pultrusion/extrusion method 
in which continuous transit or longitudinal fiber or roving is coated with 
a thermosetting resin. The fibers are then combined with one or more 
fibrous reinforcing mats and pass through a second die to cure the 
thermosetting resin. This process forms a first profile. The surface of 
the substantially cured thermoset is then deformed and a thermoplastic 
resin is then applied to the deformed surface. The deformity in the 
thermosetting surface provides increased adhesion between the thermoset 
core and the thermoplastic exterior. 
Hirao et al., U.S. Pat. No. 5,030,408 teach a method of forming a molded 
resin article combining both thermoplastic and thermosetting resins in a 
kneader extruder to form the article. The structures manufactured by 
agglomerating thermoplastic materials having a particle diameter of 
0.05-0.5 .mu.m with particles of 10-1000 .mu.m diameter prior to kneading, 
then introducing the thermoplastic material into the kneader. 
Strachan, U.S. Pat. No. 5,120,380 teaches a method of forming extruded 
profiles. In the process, cloth, preferably woven fiberglass is delivered 
by supply rolls and guided over the external profiled surface of a forming 
duct. The cloth is maintained in a shape by an air stream provided by a 
venturi blower. The air stream blows towards the die and at least 
partially diffuses through the cloth prior to the resin curing die. The 
air shaped cloth runs into a curing die where it is impregnated with a 
thermosetting resin. The thermosetting resin is cured into an extruded 
profile which is then withdrawn from the curing station using a pultrusion 
tractor device. The prior art shows a variety of 
thermoplastic/thermosetting composite materials that can be used as 
structural members. No one structure or method appears to be superior in 
forming structural members that can resist high structural loads in the 
varying temperatures found in the natural environment. Substantial need 
exists for improving the heat distortion temperature of composite 
structures. cl BRIEF DISCUSSION OF THE INVENTION 
The structural member of the invention comprises a core thermoplastic fiber 
reinforced non-circular profile having at least a covering comprising a 
fiber reinforced thermosetting layer. This structure can be manually laid 
up or made in a continuous pultrusion process. We have also found that the 
very high strength structural members can be manufactured by extruding a 
core structure comprising a fiber reinforced thermoplastic core, carefully 
calibrating the exterior of the core to form a core shape, covering the 
core with a thermoset resin fiber reinforced layer, shaping the exterior 
layer to calibrate the exterior shape and curing the exterior layer to 
form the final structural member. Such a process can be incorporated in a 
pultrusion method in which a tractor device is used to provide movement of 
the member through the process. A tractor device can contact the device 
after the fiber reinforced thermoset layer is calibrated, cured and cooled 
into a final structural member. An optional tractor device can be 
installed in a place such that they can directly contact the thermoplastic 
extrudate after calibration and cooling, but just prior to coating with 
the fiber reinforced thermoset. In the process, the cooled, calibrated, 
thermoplastic composite acts as a forming mandrel for the thermosetting 
layer. The thermoplastic fiber reinforced composite layer has 
substantially improved structural properties when compared to 
non-reinforced thermoplastics. The fiber reinforced thermoplastic, when 
adhered to the fiber reinforced thermoset in a structural member, 
cooperates to result in substantially improved mechanical properties and 
in particular, substantially improved heat distortion temperatures when 
used in a structural member under substantial load at high temperatures. 
We have found that the fiber reinforced thermosetting layer has a 
substantially higher heat distortion temperature than non-fiber reinforced 
thermoplastics. In particular, a fiber reinforced polyvinyl chloride layer 
has a sufficiently higher heat distortion temperature than the 
non-reinforced thermoplastic such that an extruded fiber reinforced 
polyvinyl chloride can act as a moving mandrel in a manual or continuous 
process for making the structural members of the invention. Substantially 
complex shapes having a substantial quantity of both thermoplastic core 
material and reinforced thermosetting material can be used in forming the 
structural member of the invention (even in the presence of substantial 
amounts of force in shaping the structure using a die or vacuum forming 
device) without any substantial change to the shape, wall thickness or 
structural integrity of the fiber reinforced thermoplastic core structure. 
The structural components of the invention can be used in the form of 
I-beams, C-channel, reinforced panels, rails, jambs, stiles, sills, 
tracks, stop and sash. The structural components of the invention can be 
heated and fused to form high strength welded joints in window and door 
assembly.

DETAILED DISCUSSION OF THE INVENTION 
The composite structural member of the invention comprises a thermoplastic 
composite linear extruded core. This extruded core member can comprise a 
thermoplastic polymer composite composition manufactured by intimately 
combining a thermoplastic polymer and a fiber material. Preferably, the 
polymer comprises a polyvinyl chloride polymer and the fiber comprises a 
cellulosic fiber. The exterior reinforcing layer that can cover a portion 
or all of the composite structural member and can comprise fiber and a 
thermosetting resin. The fiber can be applied in the form of fiber, 
fabric, rovings, yarn, thread, or other common fiber application forms. 
The fiber can be applied linearly along the extrudate or can be wrapped at 
any angle to the extruded linear member in a generally circular motion. 
In the practice of a process for forming the structural members of the 
invention, the polymer composite is melted and extruded through a profile 
die or orifice to form a rough profile shape. The profile can be solid or 
hollow. The hollow profile can have a wall thickness of about 1 mm to 10 
cm or larger if needed. The rough profile shape is then carefully 
calibrated in a sizing device which also cools the extrudate to form an 
extrudate with a carefully defined profile shape. The thermosetting resin 
and fiber are then applied to the exterior of the cooled shaped profile 
and cured to form a reinforcing layer. The thickness of the reinforcing 
layer can be about 0.5 mm to about 3 cm or larger if needed. The resin and 
fiber can also be passed through a calibration die to shape the resin and 
fiber prior to and during curing to regulate and fix the exterior 
dimensions of the structural member. In a preferred pultrusion method of 
the invention, a tractor device can be installed after the shaping and 
cooling die to pull the extruded thermoplastic linear member from the 
extrusion die through the cooling and sizing device. The pultrusion 
tractor device can be installed after the curing station forming the 
thermosetting fiber reinforced layer. Preferably, the process is run using 
a tractor to pull the completed reinforced member from the curing die. 
This tractor can be sized to provide all force needed to produce the part. 
In certain applications where stress is typically directed onto the member 
in a specific or defined stress load direction, the fiber reinforcement 
can be applied only to an area of the profile positioned to support the 
entire directional load of the stress. Alternatively, the entire surface 
of the profile can be covered with fiber reinforcement. 
Exterior Layer Comprising a Fiber-Reinforced Thermoset 
In the structural members of the application, an exterior layer is formed 
on the thermoplastic core comprising a fiber-reinforced thermoset. Such an 
exterior layer is formed using a thermosetting resin. A variety of 
thermosetting resins are known for use in such applications. Such 
thermosetting resins include unsaturated polyester resins, phenolic 
resins, epoxy resins, high-performance epoxy resins, bismaleimides 
including modified bismaleimides such as epoxy modifications, biscyanate 
modifications, rubber-toughened bismaleimides, thermoplastic-toughened 
bismaleimides, and others. In the practice of this invention, the 
preferred resins comprise unsaturated polyester resins, phenolic resins 
and epoxy resins. 
Polyester resins are manufactured by the reaction of a dibasic acid with a 
glycol. Dibasic acids used in polyester production are phthalic anhydride, 
isophthalic acid, maleic acid and adipic acid. The phthalic acid provides 
stiffness, hardness and temperature resistance; maleic acid provides vinyl 
saturation to accommodate free radical cure; and adipic acid provides 
flexibility and ductility to the cured resin. Commonly used glycols are 
propylene glycol which reduces crystalline tendencies and improves 
solubility in styrene. Ethylene glycol and diethylene glycol reduce 
crystallization tendencies. The diacids and glycols are condensed 
eliminating water and are then dissolved in a vinyl monomer to a suitable 
viscosity. Vinyl monomers include styrene, vinyltoluene, 
paramethylstyrene, methylmethacrylate, and diallyl phthalate. The addition 
of a polymerization initiator, such as hydroquinone, tertiary 
butylcatechol or phenothiazine extends the shelf life of the uncured 
polyester resin. Resins based on phthalic anhydride are termed 
orthophthalic polyesters and resins based on isophthalic acid are termed 
isophthalic polyesters. The viscosity of the unsaturated polyester resin 
can be tailored to an application. Low viscosity is important in the 
fabrication of fiber-reinforced composites to ensure good wetting and 
subsequent high adhesion of the reinforcing layer to the underlying 
substrate. Poor wetting can result in large losses of mechanical 
properties. Typically, polyesters are manufactured with a styrene 
concentration or other monomer concentration producing resin having an 
uncured viscosity of 200-1,000 mPa.s(cP). Specialty resins may have a 
viscosity that ranges from about 20 cP to 2,000 cP. Unsaturated polyester 
resins are typically cured by free radical initiators commonly produced 
using peroxide materials. A wide variety of peroxide initiators are 
available and are commonly used. The peroxide initiators thermally 
decompose forming free radical initiating species. 
Phenolic resins can also be used in the manufacture of the structural 
members of the invention. Phenolic resins typically comprise a 
phenol-formaldehyde resin. Such resins are inherently fire resistant, heat 
resistant and are low in cost. Phenolic resins are typically formulated by 
blending phenol and less than a stoichiometric amount of formaldehyde. 
These materials are condensed with an acid catalyst resulting in a 
thermoplastic intermediate resin called NOVOLAK. These resins are 
oligomeric species terminated by phenolic groups. In the presence of a 
curing agent and optional heat, the oligomeric species cure to form a very 
high molecular weight thermoset resin. Curing agents for novalaks are 
typically aldehyde compounds or methylene (--CH.sub.2 --) donors. 
Aldehydic curing agents include paraformaldehyde, hexamethylenetetraamine, 
formaldehyde, propionaldehyde, glyoxal and hexamethylmethoxy melamine. 
Epoxy resins are also used in forming thermoset-reinforcing layers. Typical 
epoxy resin systems are based on an oxirane reaction with an active 
hydrogen. Epoxy resins are generally characterized as oligomeric materials 
that contain one or more epoxy (oxirane) groups per molecule. The value of 
epoxy resins relates to their ease of processing into a variety of useful 
products or shapes including coatings, structural components of a variety 
of shape and size. Epoxy groups in the resin are cured with an appropriate 
curing agent, typically an amine. A variety of commercially available 
epoxy resins based on phenol, bisphenol, aromatic diacids, aromatic 
polyamines and others are well known. Specific examples of available 
commercial resins include a phenolic novolak epoxy resin, glycidated 
polybasic acid, glycidated polyamine (N, N, N', 
N'-tetraglycidyl-4,4'-diamino diphenol methane) and glycidated bisphenol A 
oligomers. Epoxy resins are cured into useful products using curing or 
cross linking chemical agents. Two principal classes of curing agents used 
in epoxy resins for advanced composite materials are aromatic diamines and 
acid anhydrides. Such materials include M-phenylenediamine; 4,4'-methylene 
dianiline; 4,4'-diaminodiphenyl sulfone; Nadic Methyl Anhydride; 
hexahydrophthalic anhydride; methyltetrahydrophthalic anhydride and 
others. 
Fiber-reinforcing materials that can be used in the structural members of 
the invention typically include high strength fibers such as carbon 
fibers, glass fibers, aramid fibers, steel fibers, boron fibers, silicon 
carbide fibers, polyethylene fibers, polyimide fibers and others. Such 
fibers can be used in the form a single filament, a multifilament thread, 
a yarn, a roving, a non-woven fabric or a woven fabric material. The 
fiber, roving, yarn or fabric can be applied linearly along the profile or 
wrapped, or otherwise formed on the profile in an appropriate pattern that 
can be cured to form the reinforcing structure. 
Strachan, U.S. Pat. No. 5,120,380, teaches an in-line manufacture of fiber 
filled pultruded profiles. The Strachan technology involves forming hollow 
profiles using a long heated mandrel which can be filled with foam. 
Strachan uses a driven air blast to maintain a hollow uncured member to 
prevent collapse of the profile and to maintain its shape during curing. 
This process is slow, requires long support mandrels shaped to the 
required hollow profile and limits the practicality of producing some 
profiles at economical rates. 
The process of the invention uses a continuously extruded and cooled 
profile as a mandrel upon which resin and fiber or strips of reinforced 
media are applied to the mandrel/extrudate. The use of the extrudate as a 
mandrel substantially increases throughput, provides an accurate gauge of 
sizing rapid economical throughput. Further, the process allows for 
greater thickness range of the resulting structural member, increased 
production rates, flexibility in placement of reinforcing materials, 
thermally or vibrationally weldable profiles, permits the inclusion of 
"foamed-in-place" areas to facilitate screw, nail or other fastener 
retention, has added strength over other reinforced media due to a 
synergistic bonding between the core and the reinforcing layer. The 
characteristics of the preferred thermoplastic fiber composite core 
highlighted in the improved physical properties including a high heat 
distortion temperature (HDT) in excess of 100.degree. C., a Young's 
modulus or specific modulus in excess of 500,000 psi preferably greater 
than 1,000,000 psi and an elongation at break of less than 3% and commonly 
between 1 and 3%, a tensile strength of greater than 6,500 psi. 
Method 
FIG. 1 shows the general method. Pellets of FIBREX.TM. a PVC/wood fiber 
composite of about 60 parts PVC and 40 parts wood fiber are fed into an 
extruder (1) via the extruder throat (2). The pellets are heated, mixed 
and compressed in the extruder barrel (3), and then pushed via the 
extruder screw (4) through an adapter (5) and then a shaped die (6). On 
exiting the die, the profile (7) is pulled by a puller (8) through a 
series of vacuum sizers (9) or vacuum box (10) with integral sizing plates 
(11). The vacuum sizers (9) and/or vacuum box (10) spray water (19) onto 
the profile to reduce its temperature to below the H.D.T. of FIBREX.TM.. 
This temperature is not to be construed as critical since those familiar 
with the art will recognize temperature variations as being part of the 
running process truly relevant to each profile. 
From the profile puller (8) the profile (7) is fed through a pultrusion die 
(20). 
At the same time, continuous strands of fiber (13) are soaked in a 
thermoset resin by being pulled through a wetting bath (21) and then 
through the pultrusion die (20). This process forms a bond between the 
FIBREX.TM. center mandrel and the reinforced thermoset resin. 
Those familiar with the art will recognize the possibility of substituting 
woven cloth for strands should the profile design so require it. 
Prior to entering the die (20) the resin wetted fibers are subjected to 
heating by--but not limited to--R. F. waves (12) to facilitate curing. 
Upon exiting the pultrusion die (20) the profile is fully shaped and 
cured. Dies (20 & 6) are heated and such heats are controlled to produce 
the desired profiles and affect the rate of production. 
The cured profile is pulled from the pultrusion die by a second puller (17) 
and then cut to length (18). 
FIG. 2 shows a cross-section of a structural member of the invention. The 
structural member includes a fiber reinforced thermoplastic layer 21 
covered by a fiber reinforced thermosetting layer 20. The thickness of 
these layers typically ranges from about 0.1 to about 0.3 inches. The 
structural member is in the form of a relatively complex profile shape, 
generally rectangular, having dimensions of about 1-3 inches.times.2-4 
inches. The core fiber reinforced thermoplastic mandrel shape has a 
complex structure 23 which represents a variety of complex shapes that can 
be introduced into a load bearing structural member. The fiber reinforced 
thermosetting layer 20 is introduced into a channel in the fiber 
reinforced thermoplastic layer. The material is fully contacted with the 
interior of channel 23 without the formation of any substantial bubbles or 
voids. Such complex shapes can add to both the utility of a structural 
member in a particular application or can add structural engineering 
properties to the overall member. 
The structural members of this invention are fiber-thermoset reinforced 
polymer and wood fiber extrusions having a useful cross-sectional shape 
that can be adapted to any structural application in construction of 
buildings, cars, airplanes, bridges, utility poles,etc. The members can be 
used in window or door construction and the installation of useful window 
components or parts into the structural member. The structural member can 
be an extrusion in the form or shape of rail, jamb, stile, sill, track, 
stop or sash. Additionally, non-structural trim elements such as grid, 
cove, quarter-round, etc., can be made. The extruded or injection molded 
structural member comprises a hollow cross-section having a rigid exterior 
shell or wall, at least one internal structural or support web and at 
least one internal structural fastener anchor. The shell, web and anchor 
in cooperation have sufficient strength to permit the structural member to 
withstand normal wear and tear related to the operation of the window or 
door. Fasteners can be used to assemble the window or door unit. The 
fasteners must remain secure during window life to survive as a structural 
member or component of the residential or commercial architecture. We have 
further found that the structural members of the invention can be joined 
by fusing mating surfaces formed in the structural member at elevated 
temperature to form a welded joint having superior strength and rigidity 
when compared to prior art wooden members. 
The interior of the structural member is commonly provided with one or more 
internal structural webs which in a direction of applied stress supports 
the structure. Structural web typically comprises a wall, post, support 
member, or other formed structural element which increases compressive 
strength, torsion strength, or other structural or mechanical property. 
Such structural web connects the adjacent or opposing surfaces of the 
interior of the structural member. More than one structural web can be 
placed to carry stress from surface to surface at the locations of the 
application of stress to protect the structural member from crushing, 
torsional failure or general breakage. Typically, such support webs are 
extruded or injection molded during the manufacture of the structural 
material. However, a support can be post added from parts made during 
separate manufacturing operations. 
The internal space of the structural member can also contain a fastener 
anchor or fastener installation support. Such an anchor or support means 
provides a locus for the introduction of a screw, nail, bolt or other 
fastener used in either assembling the unit or anchoring the unit to a 
rough opening in the commercial or residential structure. The anchor web 
typically is conformed to adapt itself to the geometry of the anchor and 
can simply comprise an angular opening in a formed composite structure, 
can comprise opposing surfaces having a gap or valley approximately equal 
to the screw thickness, can be geometrically formed to match a key or 
other lock mechanism, or can take the form of any commonly available 
automatic fastener means available to the window manufacturer from 
fastener or anchor parts manufactured by companies such as Amerock Corp., 
Illinois Tool Works and others. 
The structural member of the invention can have premolded paths or paths 
machined into the molded thermoplastic composite for passage of door or 
window units, fasteners such as screws, nails, etc. Such paths can be 
counter sunk, metal lined, or otherwise adapted to the geometry or the 
composition of the fastener materials. The structural member can have 
mating surfaces premolded in order to provide rapid assembly with other 
window components of similar or different compositions having similarly 
adapted mating surfaces. Further, the structural member can have mating 
surfaces formed in the shell of the structural member adapted to moveable 
window sash or door sash or other moveable parts used in window 
operations. 
The structural member of the invention can have a mating surface adapted 
for the attachment of the weigh subfloor or base, framing studs or side 
molding or beam, top portion of the structural member to the rough 
opening. Such a mating surface can be flat or can have a geometry designed 
to permit easy installation, sufficient support and attachment to the 
rough opening. The structural member shell can have other surfaces adapted 
to an exterior trim and interior mating with wood trim pieces and other 
surfaces formed into the exposed sides of the structural member adapted to 
the installation of metal runners, wood trim parts, door runner supports, 
or other metal, plastic, or wood members commonly used in the assembly of 
windows and doors. 
Using extrusion methods a pellet and extruding the pellet into a structural 
member, an extruded piece as shown in FIG. 2, extrusion 20 was 
manufactured. The wall thickness of any of the elements of the extrudate 
was about 0.165 inches. 
A Cincinnati Millicon extruder with an HP barrel, a Cincinnati pelletizer 
screws, and AEG K-20 pelletizing head with 260 holes, each hole having a 
diameter of about 0.0200 inches was used to make a pellet. The input to 
the pelletizer comprise approximately 60 wt-% polymer and 40 wt-% sawdust. 
The polymer material comprises a thermoplastic mixture of approximately 
100 parts of vinyl chloride homopolymer, about 15 parts titanium dioxide, 
about 2 parts ethylene-bis-stearimide wax lubricant, about 1.5 parts 
calcium stearate, about 7.5 parts Rohm & Haas 980-T acrylic resin impact 
modifier/process aid and about 2 parts of dimethyl tin thioglycolate. The 
sawdust input comprises a wood fiber particle containing about 5 wt-% 
recycled polyvinyl chloride having a composition substantially identical 
to the polyvinyl chloride recited above. The initial melt temperature of 
the extruder was maintained between 375.degree. C. and 425.degree. C. The 
pelletizer was operated on a vinyl/sawdust combined ratio through put of 
about 800 pounds/hour. In the initial extruder feed zone, the barrel 
temperature was maintained between 215.degree.-225.degree. C. In the 
intake zone, the barrel was maintained at 215.degree.-225.degree. C., and 
the compression zone was maintained at between 205.degree.-215.degree. C. 
and in the melt zone the temperature was maintained at 
195.degree.-205.degree. C. The die was divided into three zones, the first 
zone at 185.degree.-195.degree. C., the second zone at 
185.degree.-195.degree. C. and in the final die zone 
195.degree.-205.degree. C. The pelletizing head was operated at a setting 
providing 100-300 rpm resulting in a pellet with a diameter of about 5 mm 
and a length as shown in the following Table. 
In a similar fashion the core extruded from a vinyl wood composite pellet 
using an extruder within an appropriate extruder die. The melt temperature 
of the input to the machine was 390.degree.-420.degree. F. A vacuum was 
pulled on the melt mass of no less than 3 inches mercury. The melt 
temperatures through the extruder was maintained at the following 
temperature settings: 
______________________________________ 
Barrel Zone No. 1 
220-230.degree. C. 
Barrel Zone No. 2 
220-230.degree. C. 
Barrel Zone No. 3 
215-225.degree. C. 
Barrel Zone No. 4 
200-210.degree. C. 
Barrel Zone No. 5 
185-195.degree. C. 
Die Zone No. 6 175-185.degree. C. 
Die Zone No. 7 175-185.degree. C. 
Die Zone No. 8 175-185.degree. C. 
______________________________________ 
The screw heater oil stream was maintained at 180.degree.-190.degree. C. 
The material was extruded at a line speed maintained between 5 and 7 
ft./min. 
EXPERIMENTAL 
SHOP ORDER: MANUAL LAY UP OF OVERWRAP OF PSII BEAM WITH E-GLASS CLOTH AND 
ROOM TEMPERATURE CURE POLYESTER RESIN 
______________________________________ 
MATERIAL QUANTITIES: 
DESCRIPTION QUANTITY 
______________________________________ 
PSII beam section length &gt;15" 
(rectangular profile about 
2 inches .times. 4 inches- 
0.16 inch thickness) 
1522 E-glass plain weave fabric 
19 plies @-15" .times. 12" 
(15" dimension along warp) 
3 plies @-16" .times. 13" 
(orient for best nesting) 
Ashland Aropol 7240 T 15 room 
225 grams 
temperature cure polyester 
resin 
MEKP-9 catalyst 3 grams 
perforated release film 
1 piece @ 16" .times. 13" 
non-perforated release film 
1 piece @ 16" .times. 14" 
felt breather 1 piece @ 20" .times. 26" 
bagging film 1 piece @ 26" .times. 30" 
bag sealant tape .about.56" 
sheet metal caul plates 
2 @ 4" .times. 12" 
2 @ 2" .times. 12" 
______________________________________ 
PREATION OF MATERIALS: 
1-1. Lightly sand surface of PSII beam section with 180 grit sandpaper. 
With clean cloth and/or air clean off dust from sanding. 
1-2. Cut plies of E-glass cloth and pieces of perforated release film, 
non-perforated release film, breather, and bagging fin to dimensions given 
in "MATERIAL QUANTITIES". Cut sheet metal caul plates and remove any burrs 
or sharp edges. 
1-3. Dry fit the E-glass cloth and process materials around the PSII beam. 
1-4. Cut two holes in the bagging film for two ports, one for the vacuum 
source and one for the gauge to measure vacuum pressure. The two vacuum 
ports should be located off of the PSII beam. 
1-5. Lay down the bag sealant tape along the permieter of approximately one 
half of the bag. Do not remove the film from the sealant tape. 
1-6. Locate the two ports in the vacuum bag. 
1-7. Lay down a piece of plastic film on a flat surface where wetting-out 
of the plies will occur. 
1-8. Weigh out polyester resin in plastic container. Weigh out catalyst in 
a graduated cylinder. Add the catalyst to the resin and mix thoroughly. 
LAY-UP PROCESS: 
2-1. With PSII beam in holding fixture, brush a coat of resin on the PSII 
beam. 
2-2. On the piece of plastic film brush the resin on one 15".times.12" ply 
of E-glass cloth. 
2-3. Wrap the ply all the way around the PSII beam. Squeegee (from the 
center toward the edges) the cloth to remove any entrapped air. 
2-4. Repeat steps 2--2 and 2-3 until all 19 plies are applied to the PSII 
beam. The overlap or butt joint of each ply should be offset from the 
previous ply approximately 0.5". 
VACUUM BAGGING AND CURE: 
3-1. Wrap the perforated release film around the PSII/E-glass/polyester 
(hybrid) beam. 
3-2. Wrap the three 16".times.13" plies of E-glass cloth (bleeder) around 
the perforated release film. 
3-3. Wrap the non-perforated release film around the bleeder. 
3-4. Locate the four caul plates on each of the four faces of the beam and 
hold in place with tape. 
3-5. Wrap the breather around the caul plates. 
3-6. Remove the film from the bag sealant tape. Wrap the bagging film 
around the breather and squeeze the bag sealant tape to seal the bag. 
3-7. Connect the vacuum source and draw vacuum. Check for leaks in vacuum 
bag and seal. 
3-8. Cure at room temperature for 16 hours minimum. 
Flexural testing was conducted according to the generic specifications set 
forth by ASTM D-790. The span length was 60 inches; loading rate was 0.35 
in/min. Load versus displacement slopes were measured using an Instron 
4505. In this manner, the load versus displacement slope, m, of the 
composite beam was measured to be 1278 lb/in. 
Beam theory predicts the load slope, m, to be: 
##EQU1## 
wherein: 
E=the beam material flexural modulus, psi 
I=moment of inertia of the beam, in.sup.4 
L=beam span length between supports, in 
Flexural modulus values of FIBREX.TM. and the fiberglass reinforced 
polyester (FRP) material prepared, as described, were measured in 
separate, independent experiments. These values were found to be 740,000 
psi and 2,000,000 psi, respectively. The moments of inertia of the 
FIBREX.TM. and FRP layers (See FIG. 2) in this example are 1.273 in.sup.4 
and 2.073 in.sup.4, respectively. 
If there were no interaction between the two material layers, one would 
expect the load slope contribution from each to be additive: 
##EQU2## 
The difference between the predicted load slope (1130 lb/hr) and the 
measured load slope (1278 lb/in) demonstrates an interaction between the 
composite layers. 
Testing the adhesive bond in shear between the FIBREX.TM. and the 
fiberglass reinforced polyester (FRP) was completed according to ASTM 
D-3163. The crosshead speed used was 0.17 in/min and the bond area was 
0.25 in.sup.2. Loads in excess of 450 lbs. were applied to the bond. The 
corresponding minimum shear strength was calculated as follows: 
EQU t=P/A 
where 
P=max load (lb) 
A=bond area (in.sup.2) 
##EQU3## 
The above specification, examples and data provide a complete description 
of the manufacture and use of the composition of the invention. Since many 
embodiments of the invention can be made without departing from the spirit 
and scope of the invention, the invention resides in the claims 
hereinafter appended.