JPS6055296B2 - Manufacturing method of fiber reinforced resin structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for manufacturing a fiber reinforced resin structure (F.R.P);
That is, it relates to an improvement in the manufacturing process known as Pultrusion.

Pultrusion is a process in which resin-coated fibers are drawn through an elongated heated tube that gives shape to the structure and causes cross-linking in the resin. Typically, the fibrous material is fed into a liquid resin bath in which the individual fibers are completely coated with resin. Excess material is removed from the reinforcing resin with a brush or roller. The saturated resin-reinforced fibers are then placed in an elongated heated die.
ie), and post-curing has been performed in an open immediately after the die. In this process, an elongated die is used as the first
It is used as a heating source for curing the resin by applying heat to it through conduction. 1 Plastics Design and Processing for information on pultrusion and its general applications.
PrOcessing), May 1967 issue (pages 8 and 9), and Goldsworthy et al.
U.S. Patent No. 2,871 issued to Orthyeta
, No. 911.

A modification of the process is described in US Pat. No. 2,948,64 to Pancherz.

The basic requirements for the production of high-strength fiber-reinforced resin structures are that all fibrous materials are fully wetted with resin, that they do not break, and that they are bonded within the finished structure. There is a minimum absolute amount of resin remaining necessary to minimize the distance between adjacent fibers.

The pultrusion method that has been used up until now has not been able to fully achieve the above objectives, and the amount of energy required to pull the fiber-reinforced resin structure into the desired shape is expensive. The drawback is that it is too expensive. Furthermore, when an elongated die is used, the cured resin may locally accumulate inside the die, potentially damaging the surface of the product. The present invention provides an improved method for producing fiber reinforced resin structures by drawing resin-impregnated fibers from a die under tension.

The method of the invention consists of the following steps, which are carried out under tension.

That is, in the first step, a plurality of spaced apart continuous fibers are coated with a molten thermosetting resin.
The resin is then liquefied enough to at least partially coat the fibers, yet maintained at a temperature below the temperature at which the resin begins to harden. The coated fibers are then joined in contact and passed through an excess resin removal zone, and then spread out and passed through a preheating zone in a spaced-apart manner. Therefore, the separated fibers are separated from each other by at least one
The resin is heated with two radiant heating surfaces to reduce its viscosity, then recombined and passed through a first molding die. The fibers to be coated with resin are added at or prior to the first forming die. The recombined precoated fibers are then passed through a plurality of elongated radiant heating zones arranged in series. Each heating zone includes at least one heating surface, the surface of the heating zone being spaced apart from the resin-impregnated fibers, and each radiant heating zone arranged in series having at least one cold shaping die.
die), each die being narrow compared to the length of the radiant heating zone. In each radiant heating zone, the resin is heated by radiation and convection to allow some degree of polymerization to occur while reducing the viscosity of the resin, preferably below its initially applied viscosity. temperature is high enough to This allows greater mobility of the resin, increasing wetting of the fiber surface and aiding in the configuration of the final structure. The resin temperature achieved in each heating zone is sufficient to cause the resin to partially cure and thereby acquire sufficient viscosity such that the resin does not flow from the fiber surface. As previously mentioned, between each radiant heating zone the fibers and coating resin are placed in one or two relatively narrow
It is adapted to be drawn from one or more cold forming dies.

These molding dies are maintained at a temperature well below the temperature at which the resin begins to harden. As they pass through the orifice of each die, the resin and fibers are progressively formed into the desired cross-sectional shape, and the excess resin is drained away accordingly. This maximizes the degree of mutual compression of the fibers in the radial direction.
The die must be maintained at a sufficiently low temperature that the curing of resin expelled into the die or onto the die surface is not accelerated. This allows the ejected resin to flow over the die surface. If the expelled resin tends to accumulate on the surface of the die, it can be removed by either or both of the following methods, such as increasing the die temperature and blasting. The gelling point, the point at which heating no longer reduces the viscosity and accelerates hardening by releasing a large amount of heat per unit mass, is delayed until or just before the final die.

Once this point is reached, the resin is in a definite gel state and its structure is... shape while still maintaining workability to the extent that excess resin can be removed from the surface by a final forming die. Final curing, if performed, is deferred until a curing zone after the final die. Each of the dice arranged in series except the last die. While passing through each heating zone following the die, the resin is heated and its viscosity decreases, and after passing through the lowest viscosity point, the resin continues to harden as it moves toward the gel point with an increase in viscosity. After passing through the final heating zone in series, the resin-coated fibers reach their gel point. A radiant heat curing zone can be, and is preferably, located after the final die. Here, curing takes place by heating from the gel point to the fixed resin state, the coated resin is completely cured and the structure can be collected as a product. Without the radiation curing zone, the product would simply have to travel a longer distance to the take-up roll, so that curing would be completed before it reached the take-up roll. In the practice of this invention, each die must be maintained at a temperature close enough to facilitate its functioning as a forming die, yet to retard curing during the forming process.

Heating of the goose can be done in part by existing heating equipment, or simply by the temperature generated as the heated parallel fiber/resin matrix passes through it and by radiation from an adjacent heating zone. Heating can be achieved up to the temperature generated by heating by either or both convection currents. Importantly, the die is heated to a temperature high enough that resin exuding from the fiber-resin matrix passing through the die to the surface of the die flows and is removed from the surface without thickening or hardening. The surface is maintained. This prevents the formation of hardened resin in the orifice of the die. Otherwise, the hardened resin in the orifice would increase friction, damaging the surface of the product being molded and possibly destroying the fibers passing through the die. The speed of movement through the die and heating zone is usually controlled by the number of heating zones and series of gooses, but the minimum number of heating zones and gooses used is two each. As the number of heating zones and dies increases, feed rates can be significantly increased within the system. However, the condition must be met that reaching the gel point is delayed until or just before contact with the final die. Generally speaking, the critical significance of this point for the final die when the resin reaches its gelling point decreases as the number of dies increases. A more uniform coating of the fibers is achieved by passing the coated fibers through a preheating zone spaced apart from each other after contact;
This ultimately minimizes the amount of resin needed to produce a uniform high strength product.

The present invention will be described in detail below with reference to the accompanying drawings.

To explain FIGS. 1 and 3, the fibers included in the fiber-reinforced resin structure, or the fibers surrounding other fibers in a state of reinforcing or protecting (reinforcing), are connected to a plurality of creels. The fibers are fed by a winding frame (SpOOl) 10, and these fibers are drawn out under tension by a take-up reel 12 and, if necessary, a plow tool (COMb) 11. to remove splinters, etc.

The fibers may be run over rollers 14 and under rollers 16 in resin bath 20 to achieve initial resin coating, as shown in FIG. In this case, the coated fibers can also be passed through rollers 18 which act as squeegees to remove excess resin. Other materials may also be used to remove excess resin. A process currently considered desirable is shown in Figure 3. Referring to FIG. 3, the fibers pass through plow tool 11 over tension rollers 15 and are spread into fan-shaped rows by orifices 17 in the inlet end wall of resin bath 20.

These orifices are equipped with seals to prevent resin leakage. The fibers are coated with resin at a distance from each other and the sizing orifice 1 is provided with a leak-proof seal.
9 (Sizing Orifice), and then spread by a separating die and maintained in a separated state even in the preheating zone 22. The orifice 19 not only contacts and bonds the fibers, but also serves as a member for removing excess coating resin.
That is, for this purpose, it functions similarly to the removal roller 18 of FIG. The resin supplied is a thermosetting resin that remains liquid at ambient or slightly elevated temperatures and can be cured by heating.

There are various types of thermosetting resins, and some of them include epoxy resins such as epoxidized cyclopentadiene, polyester resins, phenol formaldehyde resins, urea formaldehyde resins, diallylphthal resins, and silicone resins. , phenolfurfural resin, urethane resin, etc., and these are selected according to the desired composition of the finished product.

Contained in the melt is a high temperature initiator or curing agent, which is only latent in the molten bath with respect to the initiation of curing, but at a certain high temperature it It works to initiate and accelerate the curing of the resin into a thermoset final product. A typical example of such a curing agent is an aromatic amine. Required inclusions include accelerators, diluent resins, fillers, colorants, flame retardants, and others. The temperature of bath 20 does not have to be too critical as long as it is maintained below the temperature at which the resin begins to harden. This is generally the RA of the resin. , is said to be a stage. Generally, typical bath temperatures range from about 20 to about 30°C. If necessary,
In order to absorb air bubbles, etc., the bath may be stirred and the operations of pressurization and depressurization may be repeated. As they pass through the bath and over the rollers 18 and into the orifices 19, the fibers are precoated with a melt of thermosetting resin and are conveyed under tension in the first radiant heating zone 22 at a distance from each other. and pass through it.

Orifice 19, in the preferred embodiment, serves to bond the fibers just before heating zone 22, and first spacing die 21 spreads the fibers through preheating zone 22. It has been found that this action results in a more uniform coating of the fibers, resulting in a product with more uniform axial strength, while at the same time achieving the desired strength. The amount of resin required to obtain is minimized. Explaining FIG. 2, in the radiant preheating zone 22, the resin is heated by radiant energy and convection received from a heating surface that is always separated from the surfaces of the resin-coated fibers that are spaced apart from each other, and polymerized. destroys the resin viscosity at the same time as starting. This results in an initial decrease in viscosity (a
-b) occurs. As a result, the resin becomes more fluid and
This allows for more complete and uniform wetting of the fibers. When curing begins, the viscosity increases accordingly (b-c) and recovers to approximately the initial viscosity. This is necessary to ensure that the resin does not run off the fiber surface before or at the forming die 24. Generally, the internal temperature of the preheater will range from about 85°C to about 130°C, depending on the starting temperature required by the accelerator to initiate curing.
℃ range. Curing begins and the RBJ stage begins at approximately the lowest point (b) of the viscosity curve illustrated in FIG. Once curing begins, the viscosity increases as several cross-linking reactions occur. The resin and fibers are then contacted again and passed through an orifice into the first cold forming die 24 (C
The fiber-reinforced resin matrix is given shape for the first time and a portion of the resin is discharged.

The ejected resin is forced out of the matrix as it passes through the die, typically flowing over the die surface. A blast of fluid, such as air, may also be generated from the jet 29 to facilitate evacuation from the die orifice. This prevents the resin from hardening or condensing on the die surface. One or more guide grids 25 may be arranged in front of the first cold-forming die, which are used to feed the fibers into the die 24 with appropriate spacing from each other. It is also possible to refill the continuous elongate internal structure from the reel 27 if desired.

As shown in FIG. 3, the fibers passing through the preheating zone are in a spaced-parallel state or in a converging fan-like state, and a grid 25 having a central opening guides the fibers from the reel 21.
in a circular pattern and pass through a circular die orifice in a bonded state. When the resin-coated fibers pass through the guide grid 25, the loss of resin is almost negligible, if at all. A die that is relatively narrow compared to the length of the radiant heating zone, is maintained at a temperature two times lower than the temperature of the adjacent heating zone and the temperature at which resin curing is accelerated, and the discharged resin is A die that acts to inhibit the curing process to the extent that it can flow over the die surface and away from the die orifice.

The die therefore allows the passage of heated fibers and resin through the die. temperature associated with the die, as well as surface temperatures resulting from radiation and convection effects from the adjacent radiant heating zone, to facilitate flow of the discharged resin over the die surface. Condensation of resin on the die, especially at the die orifice, if desired! If necessary to prevent this, the die can also be internally heated to promote flow of the discharged resin over the die surface. An effective die temperature of up to about 70° C. is used.
Referring again to FIG. 2, after passing through the cold forming die 24, where the resin may have reached a relatively constant viscosity, the composition is transferred to a heated surface that is spaced from the resin and fibers. The resin is then passed through a second radiant heating zone 26 with a temperature rise caused by radiation and convection, where the viscosity of the resin decreases again (d-e);
and curing is accelerated (e-f).

As shown in FIG. 2, after reaching the minimum value (e), the viscosity increases. This sequence is repeated as many times as necessary, and in practice may involve five or more dies arranged in series before reaching the final cold-forming die 28, which is processed in the same manner as die 24. is used.

Control of the process is such that the structure reaches the gel point (g) at or just before the final forming die 28.

1. Gelation point refers to the point at which the resin is a glass-like solid phase, yet soft enough to allow molding and removal of excess resin so that the final shape of the product can be formed. In other words, it is the point beyond which the viscosity does not decrease even if heated.

This is also the point at which curing is accelerated irreversibly.
As shown in FIG. 2, the viscosity increases rapidly over time on a relative basis, and the amount of heat generated per unit mass increases. After passing through the final space forming die 28, the formed product is typically passed through a final radiation curing zone 30, where it is heated by radiation and convection to accelerate curing, and is also passed through a take-up reel 12. The resin is cured sufficiently to allow the final product to be stretched.

When carrying out the method of the invention, the heating zones behind the first cold forming die 24 are typically maintained at a higher temperature than the first preheating zone 22, especially in the case of high temperature curing epoxy resins.
The temperature is maintained in the range of about 170 to about 2200C, or at least sufficient to weaken the resin or its viscosity to promote wetting of the fibers and filling of interstices between the fibers.

The final curing zone 30 is maintained at the same, lower, or higher temperature than one of the preceding heating zones. The hardened zone 3
0 may be operated within the same temperature range. Generally, the resin content at the exit of the first die of a series of dies is typically at a level of about 20 to about 40%, based on the total weight of resin and fibers, and the final The initial resin content is reduced by about 20 to about 25% by weight to reach .

However, the exact amount will vary depending on the desired degree of compaction between the fibers. The heating zone may have any desired cross-sectional shape and may be independent of the cross-section of the product being manufactured.

Heating can be provided by resistive coils, heating tapes, fluid streams, etc. with suitable thermostatic control. Heating of the resin and fibers is done by radiation and convection. In this case, conduction is not used. This is because there is no contact between the resin and fibers and the interior surface of the radiant heating and curing zone. Each of the radiant heating and curing zones used in practicing the method of the present invention is spaced apart from the resin and fibers passing therethrough.

With the exception of the curing zone, their function is to reduce the viscosity of the resin during the gradual progression of polymerization to the gel point, but they play no role in shaping the final structure. do not have. This forming function is reserved for relatively narrow cold forming dies. Radiant heating zone is 60.96 cm (2 feet) long
or less than 243.84c7n (8 feet)
The molding die may be approximately 0.04 to 0.64 cm (approximately 1164 to 114 inches). The orifice opening is 0.025α (a). 0
1 inch) or less to 1.27α (4). 5 inches) or more. The orifice of the die typically has a rounded entrance edge surface to reduce friction and facilitate removal of exuded resin. As a result of employing a narrow forming gear in cooperation with an adjacent radiant heating zone that performs no forming function, the energy required to obtain the finished product is reduced by the energy required to obtain the finished product, e.g.
The amount was significantly reduced compared to the method described in the issue.

Additionally, resin seeped onto the surface of the die by the flow itself and/or by the blast is continuously removed, thereby preventing resin from condensing at the orifice. . This prevents deterioration of the surface profile, which can easily occur with the elongated heated or cooled molded articles described in said patent. If the surface inside the elongated molding control section is uneven,
For example, resin may be left behind. In such cases, the resin tends to stagnate and harden, resulting in uneven spots that increase friction and detract from the shape of the product being molded. The method of the present invention can be used with any of the known fibrous materials, including metal fibers, metalloid fibers, natural organic fibers, synthetic fibers, glass fibers, and mixtures thereof.

Typical fibers include glass fiber, steel fiber, aramid fiber (polyamide resin manufactured by DuPont), carbon fiber, and the like. Among these fibers are
Also included are continuous elongated internal structures to be surrounded by other protective coatings, such as fibers of soft metals such as copper, optical fibers, and the like. The method of the invention can be applied to molding shapes with any desired cross section.

These include electrical conductors, optical fibers, and fluid conductors (FIuidcOnductOr) contained within the surrounding fiber reinforced resin structure.
) can be constructed as a relatively thin planar structure, the shaping of which is determined by a cold forming die. Tandem operation
n), i.e. by operating two or more coating units as required to pre-coat the fibers;
Multiple layers of individual fibers can also be made, thereby satisfying the required final product objectives.

For example, if a central fiber, which is a continuous, elongated internal structure, is surrounded by reinforcing fibers, a release material that does not adhere or bind the resin may be used.
), the central fiber is substantially surrounded by a casing of cured resin reinforced with fibers, and the adhesive bond between the central fiber and the resin is broken. A coated fiber structure can be produced in which the cured resin casing can be stripped off at least from the central fiber. By implementing the present invention, more precise control over the shape and quality of the final product and a significant reduction in power consumption are achieved.

Furthermore, the fibers can be pulled out from the molding device without being destroyed, and the fibers can be compacted to the maximum extent possible. Examples of the present invention are shown below, but these are not intended to limit the present invention.

Example 1 The composition of the molten thermosetting resin bath used in this example was manufactured by Shell Chemical Company (ShellCh
10 parts of epoxy resin 826 manufactured and sold by chemical company
Chemical ● Company (JeffersOnChemi)
2 parts of a curing agent known as Jeffamirle 230, manufactured and sold by caICO Company, and Accelerat 398, an accelerator manufactured and sold by Jefferson Chemical Company.
98) was 6 parts by weight.

The temperature of the bath was maintained at 15.6°C. To strengthen the coating of enamelled copper wire, Owens Corning Corporation
A bundle of glass fibers under the trade designation S-901 manufactured and sold by AtiOn) was drawn from the bath at a rate of 3.66 rT1/min (12 feet per minute). Next, the resin-coated glass fibers were passed through a first radiant preheating zone maintained at a temperature of 93° C. to reduce the viscosity of the resin for the first time. The length of the preheating zone was 2.44 wL (8 feet). The copper wire is guided into the center of the glass fiber-resin matrix and drawn out with the surrounding glass fibers and resin from a first die at a temperature of 65°C, and then a length of 1 is maintained at a temperature of 1750°C. .837TI. (6 feet)
The second radiant heating zone is used to reduce the viscosity of the bonding resin for the second time. The heated formed copper wire is then heated to 65 degrees Celsius, also at 65 degrees C
is drawn from the second die at a temperature of . The resin has reached its gel point in this second die. After passing through the second cold forming die, the gelled resin-impregnated glass fiber reinforced copper wire was maintained at a temperature of 175°C. After that, it was passed through the hardening zone. The length of the hardening zone is 3.66Tr1. (12 feet). After curing, the product was wound onto a reel. Example 2 Using the resin system of Example 1, two glass fiber pots of Owens Corning S-901, each containing approximately 201 glass filaments, were coated and placed in a resin bath. was passed at a speed of 3.66 m/min (12 ft/min).

After the initial coating, the resin and fibers are passed over a resin removal roller until the resin content per fiber is about 25 to 30% by weight, based on the total amount of resin and fibers. The resin-impregnated fibers were then passed through a first radiant preheating zone maintained at a temperature of approximately 110°C.

Like all subsequent heating zones, the preheating zone has a base width of 9.
16an (4 inches), side height 5. The 1U-shaped groove structure of ship d (2 inches) was built. Heating was accomplished using a thermostatically controlled heating tape that ran the entire length of the groove and was covered with an aluminum plate. The preheating zone is closed at the top with a removable aluminum lid. The length of this preheating zone was 2.44 TrL (8 feet). After leaving the preparatory zone, Cape 197 July 30
0.508 mm diameter buffered to a thickness of 0.508 mm (20 mils) with room temperature curing silicone rubber by the method described in the present inventor's U.S. Patent Application No. 600,20 dated.
127 (5.0 mil) optical fibers were supplemented using two guide grids in series.

BufferedOp fibers (BufferedOp) are
Optical fiber (optical fiber coated with a soft protective layer such as silicone rubber) is placed at the center and surrounded by resin-coated fibers. This combined body has a diameter of 1.
22TIn(a). A first cold-forming die having a 0.048 inch orifice and a pre-heating zone are included in the first heating zone of five separate radiant heating zones of the same construction and approximately 30 inches in length. pass through it. The cold forming die after the first heating zone of the radiant heating zone has a diameter of 1.12
TWL(4). 044 inch) and the other die orifice opening diameters are 1.02r0
t(a). 04 inches). The spacing between the heating zones was approximately 6 inches, with the die placed between them. The die surface is maintained at approximately 66° C. by radiation and convection from adjacent heating zones. The internal temperature of each of the five radiant heating zones was approximately 171°C. The resin reached its gel point just before the final die. In this method, about 20% by weight of the resin is removed from the structure, resulting in a final structure containing about 22 to about 25% resin by weight based on the total weight of resin and fibers. did. The structure had the cross-sectional shape and structure described above and was sent to a curing zone maintained at a temperature of 177°C. The length of the hardening zone is 8.537n. (28 feet). Using this method, lengths up to 3048 m (10,0
Glass fiber reinforced buffered optical fibers up to 0.00 ft.) have been produced. Example 3 Here, the order of Example 2 is repeated and the outer diameter is 1.27cm.
A 0.5 inch (0.5 inch) structure was manufactured.

A robust structure was fabricated that included embedded metal as well as buffered optical fibers. For a structure with an outside diameter of 1.27 (7n (0.5 inch)), the feed rate is reduced to 1.83 rrL/min (6 feet per minute), and the radiant preheat zone is approximately The temperature was maintained at 204°C in the middle radiant heating zone and at 17rC in the curing zone.As one skilled in the art will appreciate, the molding dies between the radiant heating zones were all arranged in series. It may be composed of a plurality of dice, or two
Each of the radiant heating zones between the two dice may consist of a plurality of radiant heating zones in series.

Example 4 Here, 100 parts by weight of epoxy resin 82 and 3 parts by weight of Naugasett Chemical Company
TOnOxHardener manufactured and sold by Rohm and Haas Chemical Company, and 4 parts by weight of TOnOxHardener manufactured and sold by Rohm and Haas Chemical Company.
D. mpany) manufactured and sold. M. P. No. (9)
2 molten bath of thermosetting epoxy resin composed of accelerator
The temperature was maintained between 1 and 24°C.

International Telegraph and Telephone Company
lephOneandTelegraphCOMpan
y) 28 fibers (Owens ◆ Corning S-
901, high glass filament) in a resin bath at a distance of 3.05 m. per minute (10 feet per minute) and bonded and passed through one aperture after exiting the resin bath to remove excess resin. Next, the fibers were separated using a spacing die with multiple openings, and the spacing between adjacent strands was set to 6.35 mm (1/4 inch). 8 feet) was passed through a preheating zone. At that time, it was kept separate from the inner surface of the preheating zone, which was maintained at a temperature of 127°C. At the outer end of the preheating zone, the optical fiber is guided into the center of a group of reinforcing resin-coated glass fibers, and the bonded fibers are brought together by 5
The fibers were passed through two consecutive sizing dies, and further passed through a heating zone with the bonded fibers and the surface of the heating zone separated.

Each heating zone is 81.3 cTn (32 inches) long and 18
A temperature of 0°C was maintained. In the final step of the process, the cured and finished reinforced optical fiber was spooled onto a 4 foot diameter reel driven by a speed controlled tension type drive motor.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the equipment and processing steps used in carrying out the method of the invention. Fig. 2 is a graph of the relative viscosity of the applied resin at each stage corresponding to Fig. 1. Fig. 3 is a schematic diagram showing the preliminary process of processing the fibers up to the first molding die. 10... Reel frame, 11...
Plow tool, 12... Take-up reel, 14, 16, 1
8...Roller, 15...Tension roller, 17...Orifice, 19...
・Sizing orifice, 20...Resin bath, 2
1... Separating die, 22... Preheating zone, 24... Forming die, 25... Guide grid, 26... Heating zone , 27... Reel, 28... Molding die, 29,372...
... Jet, 30 ... Hardening zone.

Claims (1)

[Scope of Claims] 1. Under tension, (a) a liquid thermosetting resin composition that can be cured by heating a plurality of continuous fibers in a state where the fibers are spaced apart from each other; (b) converging the coated fibers to a common point to achieve adjacent contact of the coated fibers, while discharging the fibers from a liquid that can be cured by the heating; (c) spreading the fibers from the common point to separate the resin-coated fibers; (d)
passing the resin-coated fibers through at least one elongated radiant preheating zone having at least one heated interior surface spaced apart from each other, the interior surfaces of the preheating zone being spaced apart from each other; The preheating zone is spaced apart from the resin-coated fibers, and the preheating zone heats the resin coating the fibers by radiation and convection, and adjusts the viscosity of the resin to the viscosity when the resin is introduced into the radiant preheating zone. (e) converging the heated resin-coated fibers and transferring the fibers to the radiant preheating zone and subsequent radiant irradiation. passing through a structural forming orifice, which is at least one first cold-forming die located between the heating zone and the cold-forming die, the temperature of which is sufficiently lower than the temperature at which the resin curing begins. (f) passing the fiber-coated fiber from the first cold-forming die through a number of elongated radiant heating zones, each heating zone having at least one at least one intervening cold chamber having a heated internal surface, each heating zone being spaced apart from one another and having one structural shaping orifice relatively narrower than the length of one heating zone; The heating zone is also spaced apart from the molding die, and the inner surface of each heating zone is spaced apart from the resin-coated fibers, and the heating zone heats the resin coated on the fibers by radiation and convection. Raising the temperature to a temperature higher than the temperature of the radiant preheating zone and sufficient to reduce the viscosity of the resin below the viscosity when the resin is introduced into the radiant heating zone and to further initiate curing of the resin. (g) drawing the fibers and resin from the orifice of each cold forming die between each radiant heating zone at a die temperature sufficiently below the temperature at which the resin begins to harden;
) drawing the resin-coated fibers from at least one final cold-forming die following the final heating zone of the radiant heating zone, the die being at a temperature sufficiently below the temperature at which the resin begins to harden; and allowing the resin to reach a gel point at or before contact with the final die. 2. The manufacturing method according to claim 1, wherein the thermosetting resin that can be cured by heating is an epoxy resin. 3. The method of claim 1, wherein the temperature of the liquid thermosetting resin that can be cured by heating is in the range of about 20°C to about 30°C. 4. Each of the radiant preheating zones has a temperature of approximately 85°C to approximately 130°C.
3. The method of claim 1, wherein the heating zone is at a temperature of from about 170<0>C to about 220<0>C, and wherein each of the additional radiant heating zones is at a temperature of from about 170<0>C to about 220<0>C. 5. The resin-coated fibers exiting the final die pass through a radiant heat curing zone having at least one heated interior surface, the interior surface of the curing zone being spaced apart from the resin-coated fibers; 2. The method of claim 1, wherein the fibers remain in the radiation curing zone for a sufficient period of time to fully cure the resin to a thermoset state. 6. The temperature of the radiation heating curing zone is about 170°C to about 220°C.
The manufacturing method according to claim 5, wherein the temperature is maintained at a temperature of . 7 Under tension, (a) a liquid thermosetting resin composition that can be cured by heating a plurality of continuous fibers separated from each other at a temperature below the temperature at which the thermosetting resin begins to cure; (b) converging the coated fibers to a common point to achieve adjacent contact, while removing from the fibers a liquid thermosetting resin that can be cured by the heating. (c) spreading the resin-coated fibers apart from the common point; (d)
passing the resin-coated fibers through at least one elongated radiant preheating zone having at least one heated interior surface spaced apart from each other, the interior surfaces of the preheating zone being spaced apart from each other; The preheating zone is spaced apart from the resin-coated fibers, and the preheating zone heats the resin coating the fibers by radiation and convection, and adjusts the viscosity of the resin to the viscosity when the resin is introduced into the radiant preheating zone. (e) heating the continuous elongated internal structure and the heated resin-coated fibers to a temperature sufficient to lower the temperature of the elongated structure to a temperature sufficient to initiate curing of the resin; (f) bonding at a predetermined location to the resin-coated fibers and converging the resin-coated fibers around the elongated structure;
The heated resin-coated fibers and the elongated structure bonded thereto are formed into a structural forming orifice, which is at least one first cold-forming die located between the radiant preheating zone and a subsequent radiant heating zone. (g) passing the resin-coated fiber and the elongated structure bonded thereto, such that the cold-forming die is at a temperature sufficiently lower than the temperature at which the resin cure begins; passing the body from the first cold forming die through a plurality of elongated radiant heating zones, each heating zone having at least one heated interior surface, each heating zone being spaced apart from each other; ,
It is also spaced apart from at least one intervening cold forming die that is relatively narrower than the length of one heating zone and has one structural forming orifice, the interior surface of each heating zone being It is in a state separated from the covered fibers,
The heating zone heats the resin coated on the fibers by radiation and convection to raise the temperature of the resin to a temperature higher than that of the radiant preheating zone and the viscosity of the resin when the resin is introduced into the radiant heating zone. (h) lowering the viscosity of the fibers, resin, and bonded elongated structure to a temperature sufficient to initiate curing of the resin; (i) drawing the resin-coated fibers and bonded elongate structures from the orifice of each cold-forming die between each radiant heating zone at a sufficiently low die temperature; a step of drawing from at least one final cold-forming die following the tropics,
the die is at a temperature sufficiently lower than the temperature at which the resin begins to harden, and the resin reaches a gel point at or before contact with the final die. Method of manufacturing the structure. 8. The manufacturing method according to claim 7, wherein the thermosetting resin that can be cured by heating is an epoxy resin. 9. The method of claim 7, wherein the liquid thermosetting resin that can be cured by heating is at a temperature in the range of about 20°C to about 30°C. 10 Each of the radiant preheating zones has a temperature of about 85°C to about 130°C.
8. The method of claim 7, wherein the temperature is from about 170<0>C to about 220<0>C and each of the additional radiant heating zones is from about 170<0>C to about 220<0>C. 11 The resin-coated fibers exiting the final die pass through a radiant heat curing zone having at least one heated interior surface, the interior surface of the curing zone being spaced apart from the resin-coated fibers; 8. The method of claim 7, wherein the fibers remain in the radiation curing zone for a sufficient period of time to fully cure the resin to a thermoset state. 12 The temperature of the radiation heat curing zone is about 170°C to about 220°C.
12. The method according to claim 11, wherein the temperature is maintained at a temperature of .degree.