JP6368748B2 - Molding method for molding fiber reinforced resin - Google Patents

Description

  The present invention relates to a molding processing method in which a fiber reinforced resin intermediate material in which resin powder is fused to the outer surface is heated and pressed to form a fiber reinforced resin molded article having a predetermined shape.

  In recent years, for the purpose of improving mechanical strength and reducing weight, fiber reinforced resins obtained by impregnating a resin with a reinforcing fiber substrate such as carbon fiber, glass fiber, and natural fiber have been widely used in various fields and applications. Yes. In particular, the application of fiber reinforced resin to aircraft parts and automobile parts is being actively promoted. Such fiber reinforced resin molded products are required to have complex shapes and few defects such as voids. In response to this requirement, various fiber reinforced resin intermediate materials and molding methods for fiber reinforced resin molded products are proposed. Has been.

  Patent Document 1 discloses a sheet formation in which a reinforcing fiber sheet material in which a plurality of reinforcing fibers are aligned in a predetermined direction is attached to both surfaces of a thermoplastic resin sheet material serving as a matrix resin to create a sheet-like thermoplastic resin reinforcing sheet material Thermoplastic resin multilayer reinforcement comprising: a step, a laminating step of stacking a plurality of the thermoplastic resin reinforcing sheet materials in a thickness direction, and an integrating step of integrating the thermoplastic resin reinforcing sheet materials laminated in a plurality A method for manufacturing a sheet material has been proposed. Unlike the prepreg sheet in which the thermoplastic resin material is impregnated with the thermoplastic resin material between the reinforcing fibers, the thermoplastic resin reinforced sheet material has the thermoplastic resin sheet material attached to the reinforcing fiber sheet material. The form is maintained and is easy to handle, the dispersibility of the reinforcing fibers is maintained, and the sheet is excellent in drapeability.

  Patent Document 2 discloses a composite base material using reinforcing fibers and fibers made of a resin containing an elastomer, and (1) a laminate of a reinforcing fiber cloth and a cloth containing fibers made of a resin containing an elastomer (2) A woven or knitted fabric including a woven or knitted fabric including a mixed yarn of a reinforcing fiber and a fiber made of a resin containing an elastomer; or (3) a woven or knitted fabric containing a mixed fiber of a reinforcing fiber and a fiber made of a resin containing an elastomer. There is described a fiber reinforced resin composite obtained by laminating one or a plurality of base materials, heating and pressurizing them, and melting a part or all of fibers made of a resin containing an elastomer. The object of the invention relating to this fiber reinforced resin composite is to provide a fiber reinforced resin composite base material that has both high rigidity, vibration damping properties, and weather resistance and is excellent in formability.

  Patent Document 3 is a prepreg containing a reinforcing fiber and a thermoplastic resin, having a cut in the direction of cutting the reinforcing fiber, and in all parts of the cut, the reinforcing fibers are all discontinuous, An invention relating to a prepreg in which thermoplastic resins are connected to each other with at least a part of the cut is described. In this embodiment of the prepreg, a prepreg having a 40 cm square side and a thickness of 0.1 mm made of carbon fiber as a reinforcing fiber and polypropylene as a thermoplastic resin is cut into two orthogonal cuts having a length of 30 cm. After that, the prepreg was put into a flat plate mold, and the mold was put into a press molding machine heated to 220 ° C. and pressed at a pressure of 3 MPa for 5 minutes. Thereafter, the mold was taken out, transferred to a press molding machine maintained at a temperature of 50 ° C., and pressed at a pressure of 3 MPa for 5 minutes. It is described that thermoplastic resins are connected to each other with a notch in the entire region of the prepreg, and the prepreg is easy to handle.

JP 2012-148568 Japanese Unexamined Patent Publication No. 2015-193751 JP 2014-169411 A

  In order to apply a fiber reinforced resin molded article to aircraft parts, automobile parts, etc., shapeability for molding parts having complicated shapes is required. In order to impart formability, the fiber reinforced resin intermediate material needs to be movable while maintaining the shape stability. For this reason, methods as shown in Patent Documents 1 to 3 have been proposed. The thermoplastic resin reinforced sheet material described in Patent Document 1 is obtained by adhering a reinforcing fiber sheet material on both sides of a thermoplastic resin sheet material, and heat-pressing a laminate of such thermoplastic resin reinforced sheet materials. When the fiber reinforced resin molded product is molded, there is a problem that the thermoplastic resin sheet material prevents the air contained in the reinforcing fiber sheet material from being discharged during the heating and pressing, and the air is not easily discharged.

  The fiber reinforced resin composite composed of the reinforcing fiber described in Patent Document 2 and a resin fiber containing an elastomer, or the prepreg having a notch described in Patent Document 3, is similar to the thermoplastic resin reinforced sheet material described in Patent Document 1. However, the fiber reinforced resin composite described in Patent Document 2 requires a resin fiber containing a special elastomer, and the prepreg described in Patent Document 3 has a problem that a special treatment is required.

  In view of such conventional problems, the present invention uses a fiber reinforced resin intermediate material that is excellent in formability and handleability that can use a commercially available reinforcing fiber substrate, and excellent in air exhaustability. It is an object of the present invention to provide a molding method capable of molding aircraft parts and automobile parts having complicated shapes.

  In the molding method according to the present invention, a fiber reinforced resin intermediate material in which a resin is fused to the outer surface of a reinforcing fiber base formed of reinforcing fibers is heated by a molding die composed of a heated fixed and moving mold, A molding method for forming a fiber reinforced resin molded article that is pressed and impregnated with the resin into a predetermined shape, wherein the fiber reinforced resin intermediate is formed in a state where the resin is fused to the outer surface of the reinforced fiber substrate. Heating and pressing the fiber reinforced resin intermediate material so as to crush the material and holding it, and the temperature of the fiber reinforced resin intermediate material is higher than the softening temperature of the resin fused to the reinforced fiber base material The fiber reinforced so that the applied pressure is unloaded and held, and then the pressure is gradually increased to a predetermined pressure and then held at the predetermined pressure when the resin is in a fluid state. When the resin intermediate material is repressurized Moni, heated to become a, impregnation shaping step for impregnation of the resin.

  In the above invention, the heating promotion step can be performed by adjusting the pressure applied to the reinforcing fiber base so that the applied pressure applied to the fiber reinforced resin intermediate material is maintained in the range of 0 MPa <applied pressure <20 MPa. .

  The impregnation shaping step is preferably performed after the mold is once evacuated.

  Further, the molding method according to the present invention includes heating and pressurizing a fiber reinforced resin intermediate material in which a resin is fused to an outer surface with a molding die heated to a predetermined temperature, and impregnating the fiber reinforced resin intermediate material with the resin. A molded processing method for molding a fiber reinforced resin molded product, wherein the fiber reinforced resin intermediate material, which is bulky including voids between the reinforced fibers, is heated and pressurized in the molding die, and the reinforced fibers When the fused resin is rapidly heated and the resin is softened, the pressure applied to the fiber reinforced resin intermediate material is first unloaded and held, and then the resin exhibits fluidity. The fiber reinforced resin intermediate material is re-pressurized so that the applied pressure gradually increases to a predetermined pressure, and the fiber reinforced resin intermediate material is impregnated with the fiber reinforced resin intermediate material while maintaining the predetermined pressure. The

  In the invention related to the molding method, the predetermined temperature for heating the molding die is a heating acceleration stage temperature for rapidly heating the fiber reinforced resin intermediate material in which the resin is fused to the outer surface, and fiber reinforcement performed at a temperature higher than that. The impregnation step temperature for impregnating the fiber reinforced resin intermediate material with the resin fused to the outer surface of the resin intermediate material can be set to two step temperatures.

  According to the present invention, the fiber reinforced resin intermediate material is heated quickly with little temperature unevenness in the heating promotion step, and the fiber reinforced resin intermediate material is impregnated with a resin in a fluid state in the impregnation shaping step. It can be in an easy state. For this reason, the fiber reinforced resin molded product molded according to the present invention has few voids, and can form aircraft parts, automobile parts and the like having complicated shapes.

It is a schematic diagram which shows the cross section of the fiber reinforced resin intermediate material which concerns on this invention. It is explanatory drawing of a shaping die. It is explanatory drawing of the shaping | molding processing method which concerns on this invention. It is explanatory drawing of the shaping | molding processing method of an Example.

  Hereinafter, modes for carrying out the present invention will be described. The molding method according to the present invention is a method in which a fiber reinforced resin intermediate material in which a resin is fused to the outer surface of a reinforcing fiber substrate formed of reinforcing fibers is heated and applied by a molding die comprising a heated fixed and moving die. This is a molding method for molding a fiber-reinforced resin molded product that is pressed and impregnated with the resin and molded into a predetermined shape. And the heating promotion process which heats and pressurizes the fiber reinforced resin intermediate material so as to crush the fiber reinforced resin intermediate material in a state where the resin is fused to the outer surface of the reinforcing fiber base, and When the fiber reinforced resin intermediate material becomes higher than the softening temperature of the resin fused to the reinforced fiber base material, the applied pressure is unloaded and held, and then the resin becomes fluid. The fiber reinforced resin intermediate material is re-pressurized so that the pressure is gradually increased to a predetermined pressure and then held at the predetermined pressure, and the impregnation shaping step is performed to impregnate the resin by heating. . Here, the state in which the resin exhibits fluidity means a state of the resin having a viscosity in the range of 10 to 10,000 Pa · s.

  This molding method uses a fiber-reinforced resin intermediate material in which a resin is fused to the outer surface of a reinforcing fiber base formed of reinforcing fibers. That is, a fiber reinforced resin intermediate material made of a reinforced fiber base material including a void is used. First, the material is compressed to increase its thermal conductivity and then heated. Therefore, the more the fiber reinforced resin intermediate material is laminated, the more bulky, and the more the fiber reinforced resin intermediate material is laminated, the higher the heating efficiency. The heating promotion step of compressing the fiber reinforced resin intermediate material is performed so as to crush the fiber reinforced resin intermediate material in a state where the resin is fused to the outer surface of the reinforced fiber base material. The fiber reinforced resin intermediate material is compressed in a temperature range in which the resin fused to the outer surface of the reinforced fiber base material can maintain its state in this heating promotion process, and the fiber reinforcement consolidated in the next impregnation shaping process The resin intermediate material is relaxed to properly impregnate the resin.

  This fiber reinforced resin intermediate material is flexible and follows the shape of the molding die. For this reason, since the reinforcing fiber can be deformed without breaking the reinforcing mold and along the shape of the molding die, heating of the fiber reinforced resin intermediate material can be promoted.

  In addition, when the temperature of the fiber reinforced resin intermediate material that has been compressed and rapidly raised is equal to or higher than the softening temperature of the resin fused thereto, the molding processing method first unloads the applied pressure of the fiber reinforced resin intermediate material. Hold that state. Then, re-pressurization is performed when the resin further heated and fused with the fiber reinforced resin intermediate material exhibits fluidity. By unloading the pressure applied to the fiber reinforced resin intermediate material, the consolidated reinforcing fiber base material is easily impregnated with resin in a fluid state, coupled with the repulsive force of the reinforcing fiber. . In such a state that the resin is easily impregnated, after the molten fiber is impregnated into the reinforcing fiber base while gradually increasing the pressure applied to the reinforcing fiber base, and the pressure reaches a predetermined pressure By maintaining the predetermined pressure, the impregnation of the resin into the reinforcing fiber base is completed. In this molding method, a fiber reinforced resin molded article having few defects such as voids can be efficiently and sufficiently impregnated into the reinforcing fiber base with a resin in a fluid state. When the reinforcing fiber base material that has been consolidated by unloading the applied pressure is relaxed, if the air contained in the reinforcing fiber base material is exhausted by evacuating the molding die, fibers with fewer defects such as voids A reinforced resin molded product can be molded.

  In the present invention, the fiber reinforced resin intermediate material in which the resin is fused to the outer surface of the reinforcing fiber base means that the melted resin includes not only the outer surface of the reinforcing fiber base but also a slightly impregnated state from the outer surface. The impregnation depth is not more than the depth of several reinforcing fibers forming the reinforcing fiber substrate. For example, when the reinforcing fiber is a reinforcing fiber substrate having a thickness of 200 μm made of carbon fibers having an outer diameter of 7 μm, the impregnation depth is 20 μm or less. Such a fiber reinforced resin intermediate material has, for example, the form shown in FIG. 1, and can be molded by adhering and melting resin powder on a reinforced fiber base material. According to this method, it is possible to easily form a reinforcing fiber substrate having voids inside and voids opened on the outer surface. A fiber reinforced resin intermediate material made of a reinforced fiber base material having voids opened on the outer surface is preferable because air inside the fiber reinforced resin intermediate material can be easily discharged in the heating promotion step and the impregnation shaping step. FIG. 1 shows an example of a fiber reinforced resin intermediate material. In this fiber reinforced resin intermediate material 10, after the resin powder 12 is attached to the outer surface of the reinforced fiber base material 11, the uneven shape derived from the shape, size or attached state of the resin powder 12 does not disappear. It is obtained by heating and melting to the extent that it has a resin 20 fused to the outer surface.

  Adhesion of the resin powder to the reinforcing fiber base is preferably performed using an electrostatic adhesion method. The resin powder having an average particle diameter of 1 to 500 μm can be used. The electrostatic adhesion of the resin powder is performed by spraying the resin powder on the reinforcing fiber base in a charged state so that the resin powder adheres to the outer surface of the reinforcing fiber base. This electrostatic adhesion is performed in a dry state without using a solvent or the like. The resin powder adheres to the surface of the reinforcing fiber substrate with a uniform thickness and uniform distribution when observed macroscopically, but when observed microscopically, a large number of reinforcing fibers bundled together. The surface of the reinforcing fiber base formed from the above has a portion where the resin powder is adhered to one or more layers, or a portion where the resin powder is not adhered. In such a portion, the voids present inside the reinforcing fibers are in a state of opening on the outer surface of the reinforcing fiber base, and the reinforcing fibers have voids opened on the outer surface. Such a state is determined so that the fiber volume content of the reinforcing fiber base becomes a predetermined value based on the outer diameter of the reinforcing fiber forming the reinforcing fiber base and the bulk density of the reinforcing fiber base. Can be produced by electrostatically adhering a resin powder having an average particle diameter of 2 to a reinforcing fiber substrate. In the present invention, the outer surface of the reinforcing fiber base means an open surface of the reinforcing fiber base.

  The target resin in the present invention is not limited to a thermoplastic resin. For example, a thermosetting resin that exhibits a thermoplastic resin-like behavior when the portion where the curing reaction has occurred is 10% or less can also be the subject of the present invention. Thermoplastic resins include polycarbonate (PC), polysulfone (PSU), polyethersulfone (PES), polyamideimide (PAI), polyetherimide (PEI), polyamide resins (PA6, PA11, PA66), polybutylene terephthalate ( PBT), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyether ketone ketone (PEKK) and the like can be used. A phenol resin, a polyimide resin, etc. can be used for a thermosetting resin.

  The reinforcing fibers are preferably carbon fibers, and glass fibers, natural fibers, aramid fibers, boron fibers, polyethylene fibers, and reinforced polypropylene fibers can be used. Reinforcing fiber base material should be composed of filamentous or woven reinforcing fibers using reinforcing fibers, or discontinuous reinforcing fibers that are randomly oriented two-dimensionally or three-dimensionally. Can do. For example, a UD sheet can be used as a filamentous reinforcing fiber substrate. The fiber reinforced resin intermediate material may be a single layer or may be laminated.

In the present invention, the molding die for heating and pressurizing the fiber reinforced resin intermediate material is composed of a fixed and movable die and capable of temperature control. For example, in the case of a thermoplastic resin, the temperature of the molding die is a predetermined temperature that is higher than the melting point in the case of a crystalline resin, a predetermined temperature that is higher than the glass transition temperature in the case of an amorphous resin, and is cured in the case of a thermosetting resin. The temperature is set to a predetermined temperature at which reaction occurs. However, in such a case, the temperature control of the fiber reinforced resin intermediate material in the heating promotion step and the impregnation shaping step may be strict. For this reason, the temperature of the molding die can be set to different predetermined temperatures in the heating promotion step and the impregnation shaping step. For example, when the melting point of the crystalline thermoplastic resin is T _m , when the temperature of the molding die in the heating acceleration step is T _L , and the temperature of the molding die in the impregnation shaping step is T _U , T _L ≦ Let T _m <T _U.

  In the present invention, the Vicat softening temperature (JIS K7206) or the deflection temperature under load (JIS K7191-3) can be used as the softening temperature of the resin fused to the reinforcing fiber substrate. Whether the Vicat softening temperature or the deflection temperature under load is used as the softening temperature is determined in consideration of the type of resin to be used, molding conditions, and the like.

  The pressurization of the fiber reinforced resin intermediate material is preferably performed in the range of 0 MPa <pressing force <20 MPa in the heating promotion step. If the applied pressure is too high in the heating promotion step, the reinforcing fiber may break. In the impregnation shaping step, the applied pressure is preferably 40 MPa or less, judging from the pressurization time, damage to the reinforcing fiber substrate, economy, and the like.

  An embodiment of the present invention will be described with reference to the drawings. First, a molding die composed of the fixed die 30 and the moving die 40 shown in FIG. Then, the fiber reinforced resin intermediate material 10 is placed on a molding die maintained at a predetermined temperature. Next, the moving mold 40 is closed to the fixed mold 30, and as shown in FIG. 3, (1) the fiber reinforced resin intermediate material is heated and pressurized, and the state is maintained when a predetermined pressure is reached. At this time, the fiber reinforced resin intermediate material is pressurized so that the applied pressure is maintained in the range of 0 MPa <applied pressure <20 MPa. In this heating promotion step, the gap between the reinforcing fibers of the fiber reinforced resin intermediate material and the gap formed in the laminated portion when the fiber reinforced resin intermediate material is laminated are crushed to improve the thermal conductivity. The intermediate fiber reinforced resin material is heated rapidly. (2) Next, when the temperature of the fiber reinforced resin intermediate material becomes equal to or higher than the softening temperature of the resin, the pressure applied to the fiber reinforced resin intermediate material is unloaded and this state is maintained. As a result, the reinforcing fiber base material that has been consolidated in the heating promotion step is relaxed, and voids are generated inside. (3) Then, when the temperature of the fiber reinforced resin intermediate material is further raised and the resin is in a state of flowing, the applied pressure is gradually increased, and when the predetermined pressure is reached, this is maintained. Thereby, the impregnation of the resin into the fiber reinforced resin intermediate material is appropriately performed. When the impregnation of the resin is completed, the fiber reinforced resin intermediate material is unloaded from the cooling and pressing force, released from the molding die, and a fiber reinforced resin molded product with few defects such as voids is formed.

A fiber reinforced resin intermediate material was produced using a polyamide resin (PA6, melting point 225 ° C.) and a PAN-based carbon fiber woven fabric (plain weave, basis weight 198 g / m ₂ ), and a test for molding a fiber reinforced resin molded product was performed. When fifty fiber reinforced resin intermediate materials were laminated so that the thickness of the fiber reinforced resin molded product was 10 mm, the thickness was 30 mm. This fiber-reinforced resin intermediate material was placed on a molding die maintained at 220 ° C., and pressure changes at 0 MPa, 0.1 MPa, 1 MPa, 5 MPa, and 10 MPa were performed to measure temperature changes at the center of the fiber-reinforced resin intermediate material. The results shown in Table 1 were obtained. Based on the results in Table 1, the pressure applied to the fiber-reinforced resin intermediate material to be described below was 1 MPa.

  A fiber-reinforced resin intermediate material formed by laminating 10 of the above-mentioned reinforcing fiber bases is heated and pressurized as shown in FIG. 3 using a molding die shown in FIG. Was molded. That is, the fiber reinforced resin intermediate material was placed on a molding die having a temperature of 240 ° C., and the fiber reinforced resin intermediate material was pressurized at 1 MPa. The pressure was maintained until the temperature of the fiber-reinforced resin intermediate material reached 220 ° C., and then the pressure was reduced to 0.1 MPa, and the state was maintained for 60 to 90 seconds. Next, when the fiber reinforced resin intermediate material is heated to a molding die temperature of 240 ° C. and the polyamide resin fused to the outer surface of the reinforced fiber base material becomes fluid, the fiber reinforced resin intermediate material is The pressure was gradually increased and held for 60 seconds when the applied pressure reached 5 MPa. Thereafter, the molding die was cooled to 70 ° C. or lower, and the molded fiber-reinforced resin molded product was taken out from the molding die. A specimen for a bending test was produced from the obtained fiber reinforced resin molded product, and the bending strength was measured according to JIS K7074. The bending strength averaged 946 MPa. When the cross section of the test piece was observed, the void ratio was 0.1% or less. In this molding test, the temperature and the applied pressure were controlled by a program. However, it was difficult to completely unload the applied pressure, and the setting was set to 0.1 MPa (decompression).

  In Example 2, the temperature of the molding die was maintained at different temperatures in the heating stage and the impregnation stage, and a fiber-reinforced resin molded article was molded. A fiber reinforced resin intermediate material formed by laminating 10 reinforcing fiber base materials in the same manner as in Example 1 was prepared, and heated and pressed as shown in FIG. 4 using a molding die shown in FIG. A fiber-reinforced resin molded product was molded. That is, the fiber reinforced resin intermediate material was placed on a molding die having a temperature of 220 ° C., and the fiber reinforced resin intermediate material was pressurized at 1 MPa. After maintaining the pressure for 60 seconds, the pressure was reduced to 0.1 MPa and the state was maintained for 60 to 90 seconds. Next, the temperature of the molding die is raised to 240 ° C., and when the polyamide resin fused to the outer surface of the reinforcing fiber base becomes fluid, the intermediate material of the fiber reinforced resin is gradually pressurized and applied. When the pressure reached 5 MPa, the pressure was maintained for 60 seconds. Thereafter, the molding die was cooled to 70 ° C. or lower, and the molded fiber-reinforced resin molded product was taken out from the molding die. A specimen for a bending test was created from the obtained fiber reinforced resin molded product, and the bending strength was measured in accordance with JIS K7074. The bending strength was an average of 950 MPa. When the cross section of the test piece was observed, the void ratio was 0.1% or less.

10 Fiber reinforced resin intermediate material
11 Reinforcing fiber substrate
12 Reinforcing fiber
20 Molten resin powder
30 Fixed mold
40 Moving mold

Claims (5)

A fiber reinforced resin intermediate material in which a resin is fused to the outer surface of a reinforcing fiber base formed of reinforcing fibers is heated and pressed by a molding die composed of a heated fixed and moving die, and the resin is impregnated to be predetermined. A molding processing method for molding a fiber-reinforced resin molded product molded into a shape,
A heating promoting step of heating and pressurizing the fiber reinforced resin intermediate material so as to crush the fiber reinforced resin intermediate material in a state where the resin is fused to the outer surface of the reinforced fiber base material and maintaining the heated and pressurized state. When,
When the temperature of the fiber reinforced resin intermediate material is equal to or higher than the softening temperature of the resin fused to the reinforcing fiber substrate, the pressure is unloaded and the unloaded state is maintained, and then the resin is fluid. The step of impregnating and shaping the fiber-reinforced resin intermediate material is repressurized so that the pressure is gradually increased to a predetermined pressure and then maintained at the predetermined pressure, and the resin is impregnated by heating. And a molding method comprising:   The heating promotion step is performed by adjusting the pressure applied to the reinforcing fiber base so that the pressure applied to the fiber reinforced resin intermediate material is maintained in a range of 0 MPa <pressing pressure <20 MPa. Item 2. A forming method according to Item 1.   3. The molding method according to claim 1, wherein the impregnating and shaping step is performed after the inside of the molding die is once evacuated. A molding process in which a fiber reinforced resin intermediate material in which a resin is fused to the outer surface is heated and pressurized by a molding die heated to a predetermined temperature, and a fiber reinforced resin molded product in which the resin is impregnated with the resin is molded. A method,
The fiber reinforced resin intermediate material, which is bulky with voids between the reinforced fibers, is heated and pressurized in the molding die, and the reinforced fibers and the fused resin are rapidly heated to soften the resin. First, the pressure applied to the fiber-reinforced resin intermediate material is unloaded and the unloaded state is maintained, and then the pressure is gradually increased to a predetermined pressure when the resin is in a fluid state. A molding method in which the fiber-reinforced resin intermediate material is re-pressurized, and after the predetermined pressure is reached, the state of the predetermined pressure is maintained and the fiber-reinforced resin intermediate material is impregnated with the resin.   The predetermined temperature for heating the molding die is the heating acceleration stage temperature for rapid heating of the fiber reinforced resin intermediate material in which the resin is fused to the outer surface and the outer surface of the fiber reinforced resin intermediate material that is heated at a higher temperature. The molding method according to claim 4, wherein the temperature is an impregnation stage temperature for impregnating a fiber reinforced resin intermediate material with a resin and two stage temperatures.

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