JP4548243B2 - Molding method of molded products - Google Patents

Description

  The present invention relates to a method for molding a molded product such as FRP (fiber reinforced plastic).

  In general, many molded articles made of a synthetic resin are manufactured by an injection molding method. However, sinks or pits may occur in the obtained molded article due to volume shrinkage of the synthetic resin after molding. In the case of a molded product of FRP (fiber reinforced plastic), several molding methods are known, but in particular, a reinforced fiber base material (woven fabric, knitted fabric, nonwoven fabric laminate or three-dimensional woven fabric, three-dimensional knitted fabric, In order to mold FRP using a random mat or the like, an RTM (Resin Transfer Molding) molding method is often used because of advantages such as a short molding cycle and high productivity. In the RTM molding method, a reinforcing fiber base is placed in a cavity formed in a mold, a synthetic resin is injected into the cavity, and the synthetic resin is impregnated in the reinforcing fiber base. The resin is cured and demolded after curing to obtain an FRP molded product.

Molded articles using such an RTM molding method usually include voids due to poor impregnation of the synthetic resin into the reinforcing fiber base and unimpregnated portions of the synthetic resin into the reinforcing fiber base in addition to sink marks and pits. Defects such as the occurrence of defects may occur. For this reason, a reinforcing fiber is formed by forming a resin flow channel in the cavity and injecting a synthetic resin from the injection port into the cavity through the resin flow channel with an injection pressure in the range of 0.05 to 5 MPa. There has been proposed an RTM molding method in which a base material is impregnated with a synthetic resin under pressure (for example, Patent Document 1).
JP 2004-58650 A

  By the way, in the RTM molding method of Patent Document 1, air venting from the vent and impregnation of the synthetic fiber into the reinforcing fiber base are effectively performed through the resin flow channel, but from the injection port in the cavity. There is a possibility that the effect of pressurizing the synthetic resin from the injection port may not be sufficiently exhibited in the far part, that is, the part near the vent in the cavity. For this reason, defects such as generation of voids due to poor impregnation of the synthetic resin into the reinforcing fiber base and generation of an unimpregnated portion of the synthetic resin into the reinforcing fiber base occur in the portion near the vent in the cavity. There was a risk that the quality of the molded product would deteriorate. In the injection molding method described above, similarly, in the portion far from the injection port in the cavity, the effect of pressurizing the synthetic resin from the injection port is not sufficiently exhibited, so that the molded product has sink marks, pits, voids, etc. There was a possibility that the defect of this becomes easy to generate | occur | produce.

  The present invention has been made paying attention to such problems. The object is to provide a method for molding a molded product that can improve the quality of the molded product.

In order to achieve the above object, the invention according to claim 1 is characterized in that a synthetic resin is injected and filled into the cavity from the injection port while reducing the pressure inside the cavity of the mold through the vent. synthetic resins was to overflow out of the cavity through the vent from the cavity, then again injected were to overflow synthetic resin to the pressure to the cavity to resist extravasation pressure from said vent Thus , the gist is to inject the synthetic resin into the cavity from the injection port and to inject the overflowed synthetic resin into the cavity from the vent .

  According to the above configuration, the synthetic resin injected from the injection port into the cavity actively overflows from the vent to the outside of the cavity, and the synthetic resin in the cavity flows well in the vent direction. Therefore, even if bubbles are mixed in the synthetic resin injected into the cavity, the bubbles move together with the synthetic resin from the cavity to the outside of the cavity via the vent and are well removed from the cavity. In addition, after overflowing from the cavity through the vent to the outside of the cavity, a pressure against the overflow pressure from the vent is applied to the overflowing synthetic resin, so the synthetic resin is also in the vicinity of the vent in the cavity. The pressurizing effect is exhibited. Therefore, it is possible to effectively suppress the occurrence of defects such as sink marks, pits or voids in the molded product, and the quality of the molded product is improved. The term “injection” as used in the present invention is not only to extrude the synthetic resin into the cavity, but also to apply a relatively high pressure to the synthetic resin with respect to the pressure in the cavity and use the differential pressure for the synthetic resin. Pouring into the cavity.

  According to a second aspect of the present invention, in the first aspect of the present invention, the pressure at which the synthetic resin overflowing out of the cavity is pressurized so as to resist the overflow pressure from the vent is the note. The gist is that the pressure is the same as that when the synthetic resin is injected into the cavity from the inlet.

  According to the above configuration, the synthetic resin is injected into the cavity from both the inlet and the vent, and both pressures when injecting the synthetic resin into the cavity at that time are in the cavity. Therefore, a uniform molded product can be obtained.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the synthetic resin is injected into the cavity with a reinforcing fiber base disposed in the cavity. The gist.

  According to the said structure, the molded article which uses a reinforced fiber base material as a core material can be manufactured. In addition, the molded product exhibits the pressurizing effect of the synthetic resin even in the vicinity of the vent in the cavity, so that the impregnation property of the synthetic resin to the reinforcing fiber substrate is also improved. Therefore, it effectively suppresses the occurrence of defects such as voids due to sink marks, pits or poor impregnation of the synthetic resin into the reinforcing fiber base material, and generation of non-impregnated portions of the synthetic resin with respect to the reinforcing fiber base material. It becomes possible to obtain a molded product of high quality FRP (fiber reinforced plastic).

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the synthetic resin is placed in the cavity before the viscosity of the synthetic resin exceeds 1000 mPa · s. The gist is to overflow from the cavity through the vent.

  When the viscosity of the synthetic resin exceeds 1000 mPa · s in the cavity, the fluidity of the synthetic resin is lowered, and the synthetic resin hardly overflows from the cavity through the vent. Therefore, even if bubbles are mixed in the synthetic resin injected from the inlet into the cavity, the bubbles are not moved out of the cavity. In this regard, according to the above configuration, the synthetic resin injected from the injection port into the cavity overflows from the cavity to the outside of the cavity at a stage before the viscosity exceeds 1000 mPa · s. Therefore, bubbles mixed in the synthetic resin in the cavity are smoothly moved out of the cavity together with the synthetic resin and removed.

  According to a fifth aspect of the present invention, in the third aspect of the invention, the synthetic resin that has overflowed out of the cavity is overflowed from the vent before the viscosity of the synthetic resin exceeds 300 mPa · s. The gist is to apply pressure to resist pressure.

  When the viscosity of the synthetic resin exceeds 300 mPa · s inside and outside the cavity, the synthetic resin becomes difficult to be impregnated into the reinforcing fiber base disposed in the cavity. In this respect, according to the above-described configuration, the synthetic resin is efficiently and smoothly impregnated into the reinforcing fiber base material at a stage before the viscosity exceeds 300 mPa · s.

  ADVANTAGE OF THE INVENTION According to this invention, the molding method of the molded product which can improve the quality of a molded product can be provided.

Hereinafter, an embodiment in which the present invention is embodied in a method for molding a molded product of FRP (fiber reinforced plastic) will be described with reference to the drawings.
As shown to Fig.1 (a), the molded article 11 of this embodiment is FRP (Fiber Reinforced Plastics; fiber reinforced plastic), and has comprised the substantially square plate shape. That is, as shown in FIG. 1 (b), the molded product 11 is composed of a fiber reinforced plastic 14 obtained by impregnating a synthetic fiber 13 into a reinforcing fiber base material 12 as a core material of the molded product 11 and curing it. It is. In addition, the edge part of the molded article 11 consists only of the synthetic resin 13 corresponding to the resin channel | path 24 mentioned later. As the reinforcing fiber base 12, a fiber base made of glass fiber, carbon fiber, aramid fiber or the like, for example, a woven fabric, a knitted fabric, a nonwoven fabric laminate or a three-dimensional woven fabric, a three-dimensional knitted fabric, a random mat, or the like is used. In the present embodiment, a three-dimensional fabric is used, and the structure is schematically illustrated on the drawing. As the synthetic resin 13, a thermosetting resin such as an unsaturated polyester resin, an epoxy resin, or a phenol resin, and various thermoplastic resins are used.

Next, the structure of the shaping | molding die for shape | molding the molded article 11 is demonstrated.
As shown in FIG. 2, the molding die 20 includes a fixed die 21 and a movable die 22 disposed below the fixed die 21 so as to be movable in the vertical direction (vertical direction). On the upper surface of the movable die 22, a concave portion 23 having a square shape in plan view is provided (see FIG. 3). Then, when the mold 20 is moved and the movable mold 22 is brought into contact with the fixed mold 21, that is, when the mold 20 is clamped, the concave portion 23 of the movable mold 22. And a cavity S is formed between the lower surface 21a of the fixed die 21. The mold 20 is provided with a temperature adjusting mechanism (not shown) that adjusts the temperature of the mold 20.

  In the recess 23, a gap is formed between the inner side surface 23 a of the recess 23 and the reinforcing fiber substrate 12 when the reinforcing fiber substrate 12 is placed in the central portion of the recess 23. ing. The gap functions as a resin passage 24 through which the synthetic resin 13 flows when the synthetic resin 13 is injected into the cavity S. That is, the resin passage 24 has a quadrangular annular shape surrounding the reinforcing fiber base 12 in plan view (see FIG. 3).

  Two injection ports 25 and 26 for injecting the synthetic resin 13 into the cavity S are provided on the lower surface 21 a of the fixed mold 21, and both the injection ports 25 and 26 are both connected via an injection tube 27. It is connected to an injector 28 for injecting the synthetic resin 13. That is, one injection pipe 27 extending from the injection machine 28 is branched into two in the fixed mold 21, and the two branched injection pipes 27 are connected to both injection ports 25 and 26, respectively. . In this case, both the injection ports 25 and 26 are disposed so as to correspond to both corner portions of the resin passage 24 facing each other with the center of the recess 23 in plan view (see FIG. 3).

  Further, two vents 29 and 30 are provided on the lower surface 21 a of the fixed mold 21, and both the vents 29 and 30 are both connected to a resin container 32 outside the cavity S via a vent pipe 31. . That is, one vent pipe 31 extending from the resin container 32 is branched into two in the fixed mold 21, and the two bent pipes 31 are connected to both vents 29 and 30, respectively. In this case, both the vents 29 and 30 are arranged side by side at a predetermined interval at a position corresponding to the center of the recess 23 in plan view (see FIG. 3). The resin container 32 is formed of a colorless and transparent heat-resistant glass.

  In addition, a decompression pump 34 is connected to the resin container 32 via a suction pipe 33, and the decompression pump 34 is driven to drive the resin container 32, the vent pipe 31, and the cavity S through the suction pipe 33. The pressure is reduced. A suction opening / closing valve 35 for opening and closing the inside of the suction pipe 33 is provided at an intermediate portion of the suction pipe 33. Further, an air cylinder 37 is connected to the resin container 32 via a pressurizing pipe 36, and the inside of the resin container 32 is pressurized via the pressurizing pipe 36 by driving the air cylinder 37. . A pressurizing on / off valve 38 for opening and closing the inside of the pressurizing pipe 36 is provided at an intermediate portion of the pressurizing pipe 36.

Next, a method for forming the molded product 11 will be described.
As shown in FIG. 4, when molding the molded product 11, first, the reinforcing fiber base 12 is placed in the center of the concave portion 23 of the movable mold 22, the mold 20 is clamped, and the mold 20 Is maintained at 50 ° C. Then, the suction on / off valve 35 is opened and the pressure on / off valve 38 is closed, and the decompression pump 34 is driven to decompress the inside of the cavity S to a state close to a vacuum. Subsequently, in a state where the inside of the cavity S is depressurized, the synthetic resin 13 (the epoxy resin in the present embodiment) to which the curing agent is added is injected into the cavity from the injection machine 28 through the injection pipe 27 and the two injection ports 25 and 26. Inject into S. In the present embodiment, the synthetic resin 13 is poured into the cavity S by the differential pressure between the pressure in the cavity S and the pressure by the injector 28. Furthermore, in this embodiment, Araldite LY5052 (trade name) manufactured by Huntsman Advantest Materials is used as the epoxy resin used as the synthetic resin 13, and Aradur manufactured by Huntsman Advantest Materials is used as the curing agent. 5052 (trade name) is used.

  Then, the synthetic resin 13 injected into the cavity S flows into the cavity S so as to surround the reinforcing fiber base 12 through the resin passage 24 (see FIG. 5). The synthetic fiber 13 flowing through the resin passage 24 is smoothly impregnated into the reinforcing fiber base 12. Subsequently, of the synthetic resin 13 injected into the cavity S, the synthetic resin 13 reaching the vicinity of the vents 29 and 30 overflows into the resin container 32 through the vents 29 and 30 and the vent pipe 31. The resin container 32 is temporarily stored. At that time, since the synthetic resin 13 in the cavity S flows toward the vents 29 and 30 from the inlets 25 and 26, bubbles mixed in the synthetic resin 13 move into the resin container 32 together with the synthetic resin 13. To be removed.

  Thereafter, when the viscosity of the synthetic resin 13 temporarily stored in the cavity S and the resin container 32 reaches 1000 mPa · s (predetermined value), the suction on-off valve 35 is closed to stop the decompression pump 34, The pressure on / off valve 38 is opened to drive the air cylinder 37. That is, the synthetic resin 13 in the resin container 32 is pressurized so as to resist the overflow pressure of the synthetic resin 13 from the vents 29 and 30. Then, the synthetic resin 13 temporarily stored in the resin container 32 is injected into the cavity S through the vent pipe 31 and both vents 29 and 30.

  In this case, in a state where the viscosity of the synthetic resin 13 is 1000 mPa · s or less, the bubbles mixed in the synthetic resin 13 can move, so that the removal of the bubbles can be expected. Furthermore, if the viscosity of the synthetic resin 13 is 1000 mPa · s or less, pressurizing the synthetic resin 13 against the overflow pressure also improves the impregnation of the synthetic resin 13 into the reinforcing fiber base 12. I can expect.

  On the other hand, when the viscosity of the synthetic resin 13 exceeds 1000 mPa · s, the bubbles mixed in the synthetic resin 13 do not move, and the bubbles cannot be removed. Furthermore, when the viscosity of the synthetic resin 13 exceeds 1000 mPa · s, the effect of improving the impregnation property to the reinforcing fiber base 12 by pressurization against the overflow pressure from both the vents 29 and 30 becomes low. Therefore, the predetermined value may be 1000 mPa · s or less. As in this embodiment, if the viscosity of the synthetic resin 13 is 1000 mPa · s, air bubbles in the synthetic resin 13 can be removed as much as possible, and the pressure against the overflow pressure from both vents 29 and 30 can be obtained. The improvement of the impregnation property to the reinforcing fiber base 12 can be expected.

  Further, in this case, whether or not the viscosity of the synthetic resin 13 temporarily stored in the resin container 32 has reached 1000 mPa · s is managed by the heating time of the synthetic resin 13. In the embodiment, 22 minutes) is obtained in advance by experiments. Here, the heating time until the viscosity of the synthetic resin 13 reaches 1000 mPa · s is obtained as follows.

  The synthetic resin 13 (epoxy resin) to which the curing agent was added was measured for changes in viscosity of the synthetic resin 13 over time using a B-type viscometer in an oil bath atmosphere at a constant temperature of 50 ° C. The measurement results are shown in the graph shown in FIG. That is, as the temperature of the synthetic resin 13 increases, the viscosity of the synthetic resin 13 decreases, but at the same time, since the curing reaction of the synthetic resin 13 proceeds, the temperature of the synthetic resin 13 is 38 ° C. and the heating time is 20 minutes. It can be seen that the viscosity of the synthetic resin 13 is increased and the viscosity of the synthetic resin 13 reaches 1000 mPa · s when the heating time is 22 minutes.

  Here, the pressure at the time of pressurizing the synthetic resin 13 in the resin container 32 so as to resist the overflow pressure from both the vents 29 and 30 injects the synthetic resin 13 into the cavity S from both the inlets 25 and 26. The drive control of the air cylinder 37 is performed so as to be the same as the pressure at the time. Thereby, since a pressure is equally applied with respect to the inside of the cavity S, a homogeneous molded article 11 can be obtained. Further, in the cavity S, the pressurizing effect can be exhibited in the vicinity of both vents 29 and 30 where the pressurizing effect of the synthetic resin 13 from both the inlets 25 and 26 is difficult to be exerted. The impregnation property of the synthetic resin 13 with respect to is improved. Then, after the synthetic resin 13 is completely cured, the pressure on / off valve 38 is closed and the air cylinder 37 is stopped. Thereafter, the mold 20 is opened, and the molded product 11 is removed from the mold 20.

According to the embodiment detailed above, the following effects are exhibited.
(1) The more the vents 29 and 30 are located farther from the both inlets 25 and 26, the less the pressure effect of the synthetic resin 13 is exerted near the both vents 29 and 30 in the cavity S. However, the synthetic resin 13 that has overflowed into the resin container 32 through both the vents 29 and 30 from the cavity S and temporarily stored is pressurized from the both vents 29 and 30 into the cavity S again, so that the inside of the cavity S The pressurizing effect of the synthetic resin 13 can also be exerted in the vicinity of both vents 29 and 30 in FIG.

  (2) Further, the synthetic resin 13 is injected into the cavity S from the injection ports 25 and 26 while reducing the pressure in the cavity S, and the synthetic resin 13 overflows into the resin container 32 from both vents 29 and 30. As a result, the flow toward both the vents 29 and 30 from both the injection ports 25 and 26 is favorably generated in the synthetic resin 13 in the cavity S. Therefore, bubbles mixed in the synthetic resin 13 in the cavity S can be removed by moving into the resin container 32 together with the synthetic resin 13 via both vents 29 and 30. Therefore, it is effective to cause defects such as sinks, pits, voids due to poor impregnation of the synthetic resin 13 into the reinforcing fiber base 12, and generation of non-impregnated portions of the synthetic resin 13 with respect to the reinforcing fiber base 12. Therefore, a high-quality FRP molded product 11 can be obtained.

  (3) The pressure at the time of pressurizing the synthetic resin 13 in the resin container 32 so as to resist the overflow pressure from both vents 29, 30 injects the synthetic resin 13 into the cavity S from both the inlets 25, 26. Since the pressure is the same as the pressure at the time, the pressure at the time of injecting the synthetic resin 13 is evenly applied to the inside of the cavity S, and the uniform molded product 11 can be obtained.

  (4) Since the synthetic resin 13 in the cavity S hardly flows when the viscosity of the synthetic resin 13 temporarily stored in the cavity S and the resin container 32 exceeds 1000 mPa · s, the bubbles mixed in the synthetic resin 13 Is not moved into the resin container 32. In this regard, in the present embodiment, a predetermined value (resin container) that is a guideline for pressurizing the synthetic resin 13 that has overflowed and temporarily stored in the resin container 32 so as to resist the overflow pressure from both vents 29 and 30. By setting the viscosity of the synthetic resin 13 in 32 to 1000 mPa · s, air bubbles mixed in the synthetic resin 13 can be suitably removed, and the pressure against the overflow pressure from both vents 29 and 30 The improvement of the impregnation property of the synthetic resin 13 into the reinforcing fiber base 12 can be expected.

  (5) Since the synthetic resin 13 temporarily stored in the resin container 32 is pressurized into the cavity S from both vents 29 and 30 using the air cylinder 37, the injection pressure of the synthetic resin 13 into the cavity S is increased. Can hold pressure to level.

  (6) When a plurality of vents 29, 30 are arranged side by side at a predetermined interval as in the present embodiment, the inlets 25, 26 are provided between the vents 29, 30 in the cavity S. A region where the pressurizing effect of the synthetic resin 13 is hardly exhibited is formed. However, in this embodiment, the synthetic resin 13 temporarily stored in the resin container 32 is pressurized into the cavity S from the vents 29 and 30 again, so that the pressure is also applied between the vents 29 and 30 in the cavity S. The effect can be demonstrated.

  (7) Since the synthetic resin 13 temporarily stored in the resin container 32 is again injected into the cavity S from both the vents 29, 30, the cavity is compared with a case where new synthetic resin is injected from both the vents 29, 30. Familiarity with the synthetic resin 13 in S is improved. For this reason, in the cavity S, the curing of the synthetic resin 13 can be progressed uniformly, and a uniform molded product 11 can be obtained.

  (8) Since the synthetic resin 13 overflows from the cavity S into the resin container 32 by depressurizing the cavity S, the cavity S can be kept in a vacuum state for a long time. For this reason, the impregnation property of the synthetic resin 13 with respect to the reinforcing fiber base 12 can be promoted, and as a result, the yield of the synthetic resin 13 can be improved.

(9) Since the resin container 32 is formed of transparent, colorless and transparent heat-resistant glass, the state of the synthetic resin 13 therein can be easily confirmed.
(Example of change)
In addition, the said embodiment can also be changed and actualized as follows.

  ○ The predetermined value (the viscosity of the synthetic resin 13 as a guideline when the synthetic resin 13 in the resin container 32 is pressurized so as to resist the overflow pressure from both vents 29, 30) is set to 300 mPa · s or less. May be. That is, when the viscosity of the synthetic resin 13 exceeds 300 mPa · s, the reinforcing fiber base 12 is hardly impregnated with the synthetic resin 13. For this reason, by setting the predetermined value to 300 mPa · s or less, the impregnation of the reinforcing fiber base 12 with the synthetic resin 13 by the pressurization against the overflow pressure from both the vents 29 and 30 proceeds more effectively. Therefore, the synthetic fiber 13 can be efficiently and smoothly impregnated into the reinforcing fiber base 12.

  ○ The predetermined value may be set to a value exceeding 1000 mPa · s. That is, if the synthetic resin 13 temporarily stored in the resin container 32 can be returned and injected from both vents 29 and 30 into the cavity S while being pressurized, the viscosity of the synthetic resin 13 in that case is a value exceeding 1000 mPa · s. May be.

(Circle) you may materialize in the shaping | molding method of a molded article when not arranging the reinforced fiber base material 12 in the cavity S.
In the above embodiment, the synthetic resin 13 overflowing from the cavity S is temporarily stored in the resin container 32. However, the present invention is not limited to this configuration. Even if the resin container 32 is not provided, it suffices if the vent pipe 31 or the like has a portion having a volume sufficient to temporarily store the synthetic resin 13 overflowing from the cavity S.

  In the above embodiment, the resin passage 24 is formed in a square ring shape surrounding the reinforcing fiber base 12 in a plan view, but the present invention is not limited to this configuration. The shape of the resin passage 24 may be appropriately changed according to the arrangement and number of inlets and vents. Further, a concave groove may be formed on the inner wall surface of the mold 20 forming the cavity S, and this may be used as the resin passage 24. Further, the resin passage 24 may be omitted.

  ○ The pressure when pressurizing so as to resist the overflow pressure from both vents 29 and 30 may not necessarily be the same as the pressure when the synthetic resin 13 is injected into the cavity S from both the injection ports 25 and 26. .

  In place of the air cylinder 37, a hydraulically driven cylinder or a servo motor driven cylinder may be used. In particular, when a servo motor driven cylinder is used, not only can a high pressure be applied to the cavity S, but also the injection speed and the injection amount of the synthetic resin 13 can be easily set by controlling the movement of the cylinder. can do. Further, the air cylinder 37 may be omitted, and the inside of the resin container 32 may be pressurized by directly blowing air into the resin container 32.

(Circle) the shaping | molding die 20 is good also as a structure which mutually replaced the position of both the inlet ports 25 and 26 and both the vents 29 and 30. FIG.
The number and position of both inlets 25 and 26 and both vents 29 and 30 may be changed as appropriate according to the characteristics of the molded article 11.

  As shown in FIG. 7, the molding die 20 may be configured to include a stationary die 21 and a movable die 22 arranged on the right side of the stationary die 21 so as to be movable in the left-right direction (horizontal direction). Good. In the case of this mold 20, the concave portion 23 of the movable die 22 and the reinforcing fiber base 12 are configured to have substantially the same size, and when the reinforcing fiber base 12 is disposed in the concave portion 23, Almost no gap is formed between 23a and the reinforcing fiber base 12. That is, the resin passage 24 is omitted (see FIG. 8). One injection port 40 is provided at the center of the lower end of the fixed mold 21 in the cavity S, and one vent 41 is provided at the center of the upper end of the fixed mold 21 in the cavity S. Even if comprised in this way, the effect of said (1)-(5) and (7)-(9) can be acquired.

  In the above embodiment and the modification, the inlets 25, 26, 40 and the vents 29, 30, 41 are all provided in the fixed mold 21, but they may be provided in the movable mold 22. Alternatively, the inlets 25, 26, 40 and the vents 29, 30, 41 may be separately provided in the fixed mold 21 and the movable mold 22, respectively.

  In the above embodiment, the molded product 11 has a substantially square plate shape, but the molded product 11 may have other shapes. For example, the plate shape which has a bending part may be sufficient, and arbitrary solid shapes may be sufficient. In addition, the reinforcing fiber base material 12 serving as a core material of the molded product 11 may have the same shape as the molded product 11, or may be divided and housed in the molded product 11 depending on the application of the molded product 11. Alternatively, it may be partially housed in a site where the strength of the molded article 11 is required.

(A) is a perspective view of the molded article of embodiment, (b) is the 1b-1b sectional view taken on the line of (a). Sectional drawing of the shaping | molding die of embodiment. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. Sectional drawing which shows the effect | action at the time of shaping | molding of the molded article of embodiment. FIG. 5 is a sectional view taken along line 5-5 of FIG. The graph which shows the relationship between temperature and viscosity of the synthetic resin of embodiment, and time. Sectional drawing of the shaping | molding die of the example of a change. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Molded article, 12 ... Reinforcement fiber base material, 13 ... Synthetic resin, 20 ... Mold, 25, 26, 40 ... Injection port, 29, 30, 41 ... Vent, 32 ... Resin container, S ... Cavity.

Claims (5)

While decompressing the inside of the mold cavity through the vent, the synthetic resin is injected and filled into the cavity from the injection port, and the synthetic resin overflows from the cavity through the vent to the outside of the cavity. , then, by re-injected into the cavity under pressure as was allowed to overflow synthetic resin against the extravasation pressure from the vent, as well as injected into the cavity of the synthetic resin from the injection port The molding method of injecting the overflowed synthetic resin into the cavity from the vent . The pressure at the time of pressurizing the synthetic resin overflowing out of the cavity against the overflow pressure from the vent is the same as the pressure at the time of injecting the synthetic resin into the cavity from the injection port. The molding method of the molded product according to claim 1. The method for molding a molded product according to claim 1 or 2, wherein the synthetic resin is injected into the cavity in a state where a reinforcing fiber base is disposed in the cavity. The pre-stage where the viscosity of the synthetic resin exceeds 1000 mPa · s, the synthetic resin overflows from the cavity through the vent to the outside of the cavity. Molding method for molded products. The molding of the molded article according to claim 3, wherein the synthetic resin overflowing out of the cavity is pressurized against the overflow pressure from the vent in a previous stage in which the viscosity of the synthetic resin exceeds 300 mPa · s. Method.

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