JP5617344B2 - Manufacturing method and manufacturing system of resin molded body, resin molded body, pressure vessel - Google Patents

Description

  The present invention relates to a method and system for manufacturing a resin molded body, a resin molded body, and a pressure vessel.

  As a container for storing a large volume of gas, such as oxygen or nitrogen, at normal temperature and pressure at a high density and a small capacity, a pressure container that is compressed by a predetermined pressure and stored as a liquid or gas is used. . In particular, FRP pressure vessels using fiber reinforced resin (FRP) such as carbon fiber reinforced resin (CFRP) are generally lighter than metal pressure vessels, and are therefore advantageous for mounting on moving bodies such as vehicles. In addition, when used as a pressure vessel for hydrogen, there is little concern about hydrogen embrittlement and other concerns that have been a problem with conventional steel containers, and thus attention has been focused (for example, Patent Documents 1 and 2).

  Patent Document 1 discloses a pressure vessel having a configuration in which a number of grooves are formed on the surface of a liner formed by joining a plurality of liner constituent members and a reinforcing material is covered on the outer surface of the liner.

  Patent Document 2 discloses a pressure vessel in which an oxide layer is formed on the inner surface side of a liner.

JP 2009-257355 A JP 2010-019315 A

  FIG. 4 is a diagram for explaining the outline of the configuration of a general FRP pressure vessel. The pressure vessel 10 shown in FIG. 4 is made of, for example, a nylon resin such as 6-nylon (also referred to as nylon 6) or 6,6-nylon (also referred to as nylon 66) or a thermoplastic resin having a high gas barrier property such as polypropylene resin. For example, a hollow liner 12 formed by adding an elastomer such as ethylene olefin or urethane to impart impact resistance, and a fiber reinforced resin layer (FRP layer) covering the outer periphery of the liner 12 14 and is configured. The pressure vessel 10 also has at least one base 16. The base 16 is configured to be connectable with a valve (not shown), and the flow of the high-pressure fluid into and out of the pressure vessel 10 can be adjusted by operating the valve.

  In general, for example, a liner 12 having a desired shape can be produced by producing a plurality of liner components such as a substantially cylindrical shape and a substantially bowl shape, and combining them. From the viewpoint of molding cost, durability, and the like, it is preferable to form two substantially identically shaped liner components corresponding to the pressure vessel 10 to be divided into two parts, and combine them to form the liner 12. is there.

  The fiber reinforced resin layer 14 is made of, for example, a resin liquid made of a thermosetting resin such as an epoxy resin or a polyester resin on a long continuous thread-like fiber (filament) made of, for example, glass fiber, carbon fiber, Kevlar fiber, or the like. A so-called prepreg fiber impregnated and dried if necessary is wound around the outer peripheral surface of the liner, and then the resin liquid is cured. At this time, in addition to the material and / or thickness of the liner 12, for example, by adjusting the thickness and the number of turns of the fibers constituting the fiber reinforced resin layer 14 and adjusting the thickness of the fiber reinforced resin layer 14, the pressure vessel 10. It is possible to control the pressure resistance performance and other design strengths.

  In the pressure vessel 10 having such a configuration, most of the high-pressure gas stored in the inner portion of the liner 12 is discharged through a valve (not shown) connected to the base 16. When a substance having a low molecular weight such as a high pressure is filled in the pressure vessel 10, a part of the material may permeate the liner 12. When the internal pressure of the pressure vessel 10 is relatively high and the base 16 and the liner 12 and fiber reinforced resin layer 14 in the vicinity thereof are kept airtight, the gas that has passed through the liner 12 is in the vicinity of the base 16. It stays and leakage to the outside of the pressure vessel 10 is negligible. On the other hand, when the internal pressure of the pressure vessel 10 decreases and the gas sealing performance between the base 16 and the liner 12 and the fiber reinforced resin layer 14 in the vicinity thereof decreases, the gas that has passed through the liner 12 is in the vicinity of the base 16. From the pressure vessel 10 to the outside of the pressure vessel 10 at a high concentration.

  The presence of an elastomer can be cited as one of factors that cause a substance having a low molecular weight such as hydrogen gas to permeate the liner 12. The high gas barrier property of the liner 12 containing a thermoplastic resin such as nylon resin is said to be derived from the high crystallinity of the thermoplastic resin. On the other hand, the elastomer that can be added to the molding material of the liner 12 for imparting impact resistance is generally amorphous, and depending on the amount of addition, the gas barrier property of the produced liner may be reduced. There is a case. In addition, the addition of the elastomer to the molding material of the liner 12 could possibly be a factor that hinders the crystallization of the thermoplastic resin during the molding of the liner 12.

  Conventionally, for the purpose of improving gas barrier properties by promoting crystallization of a thermoplastic resin, it is known to raise the molding temperature or to perform annealing by reheating. Annealing is also known to be useful for stress relaxation of the molded liner 12. However, molding at a higher mold temperature or resin temperature could cause other physical properties such as pressure resistance to deteriorate. On the other hand, the annealing performed in the post-process generally needs to secure a heating space for temperature control for a predetermined time, which may cause a decrease in productivity.

  An object of this invention is to manufacture the resin molding which has high gas barrier property easily.

  The configuration of the present invention is as follows.

  (1) An injection step of injecting a molding material for producing the resin molded body into a cavity corresponding to the shape of the resin molded body to be produced, which is formed in a mold having a concave mold and a convex mold, and the mold A mold cooling process for cooling the mold to form a molding intermediate in which the molding material is solidified, and a mold opening process for opening the mold and detaching the convex mold in close contact with the molding intermediate from the concave mold A mold release step of releasing at least a part of the molding intermediate from the convex mold while maintaining airtightness between the convex mold and the molding intermediate, and the molding intermediate released. A hot air supply step for supplying warm air having a temperature higher than the temperature of the convex mold to heat the molding intermediate, and the heated molding intermediate. A method of producing a resin molded body, comprising a slow cooling step of slow cooling together with the convex mold.

  (2) In the manufacturing method according to the above (1), the molding material includes a thermoplastic resin and an elastomer, and at least a part of the thermoplastic resin is obtained by the warm air supply step and the slow cooling step. A method for producing a resin molded body, which is crystallized.

  (3) The manufacturing method according to (2), wherein the thermoplastic resin is a nylon resin, and the air supply temperature of the hot air is 100 ° C. or higher.

  (4) A resin molded body produced by the manufacturing method according to any one of (1) to (3), wherein the resin molded body constitutes a pressure vessel for storing pressurized gas. A resin molded body that is a liner constituting member.

  (5) A mold including a concave mold and a convex mold and having a cavity corresponding to the shape of the resin molded body to be manufactured; an injection means for injecting a molding material for manufacturing the resin molded body in the cavity; A mold cooling means for cooling the mold and forming a molding intermediate in which the molding material is solidified, and at least one of the convex mold and the concave mold is opened, and the molding intermediate is detached from the concave mold. The mold opening means, the mold release means for releasing at least a part of the molding intermediate from the convex mold while maintaining the airtightness between the convex mold and the molding intermediate, and the mold released A system for producing a resin molded body, comprising: a hot air supply means for supplying hot air having a temperature higher than the temperature of the convex mold between the molding intermediate and the convex mold.

  (6) A resin molded body produced by the manufacturing system according to (5), wherein the resin molded body is a liner constituent member constituting a pressure vessel for storing pressurized gas. body.

  (7) A pressure vessel including a hollow liner and a fiber reinforced resin layer covering an outer periphery of the liner, and the liner includes the resin molded body according to (4) or (6).

  A resin molded body having a high gas barrier property can be easily produced.

It is a figure for demonstrating the outline of a structure of the manufacturing system of a resin molding. It is a figure for demonstrating the shaping | molding process by the manufacturing system of the resin molding shown in FIG. It is the block diagram which illustrated the manufacturing method of the resin molding. 2 is a diagram showing an outline of the configuration of a pressure vessel 10. FIG.

  Hereinafter, an outline of a configuration of a resin molded body manufacturing system according to an embodiment of the present invention will be described in detail with reference to the drawings.

  A resin molded body manufacturing system 100 shown in FIG. 1 includes a cylinder 20, a mold 26, push-up cores 28 and 30, open cores 32 and 34, and a control unit 44.

  The cylinder 20 injects a molding material containing a thermoplastic resin and an elastomer, which is heated and melted in an injection device (not shown), from a nozzle 36 provided at the tip of the cylinder 20 toward a mold 26 under set injection conditions. Configured to be able to.

  The mold 26 includes a concave mold 22 and a convex mold 24. As shown in FIG. 1, in a state where the mold 26 is closed and the concave mold 22 and the convex mold 24 are brought close to each other, a cavity 38 corresponding to the shape of the resin molded body to be produced is formed between the concave mold 22 and the convex mold 24. As described above, the surface shapes of the concave mold 22 and the convex mold 24 are respectively processed. The concave mold 22 and the convex mold 24 are each configured to be adjustable to a desired temperature by a temperature adjusting mechanism (not shown) including a heating means (not shown) and a cooling medium flow path (not shown). Yes. Further, the concave mold 22 arranged on the cylinder 20 side can be provided with a spruce bush 42 that contacts the tip of the nozzle 36 at the time of injection. Hereinafter, the concave mold 22 will be described as a fixed mold and the convex mold 24 as a movable mold. However, the concave mold 22 can be used as a movable mold and the convex mold 24 can be used as a fixed mold.

  The convex mold 24 penetrates through the inside thereof, and a hot air supply passage through which hot air sent from a hot air supply source and / or hot air supply means (not shown) can be supplied to the concave mold 22 side. 40 is formed. If necessary, a check mechanism can be provided to prevent the molding material from entering from the cavity 38.

  The push-up cores 28 and 30 are provided on the convex mold 24 side, in the vicinity of the concave mold 22, more specifically, in the vicinity of the end of the cavity 38 on the convex mold 24 side. Each of the push-up cores 28 and 30 shown in FIG. 1 protrudes toward the concave mold 22 by moving in the horizontal direction when the mold 26 is opened and the concave mold 22 and the convex mold 24 are separated from each other. It is comprised so that the shaping | molding intermediate body (after-mentioned) in 38 can be pushed up.

  On the other hand, the open cores 32, 34 can be provided on the convex mold 24 side, in the vicinity of the concave mold 22, more specifically, in the central portion closer to the nozzle 36 than the push-up cores 28, 30 or in the vicinity thereof. Each of the open cores 32 and 34 shown in FIG. 1 protrudes toward the concave mold 22 by moving in the vertical direction when the mold 26 is opened and the concave mold 22 and the convex mold 24 are separated from each other. The inner molding intermediate body (described later) can be opened in the outward direction of the convex mold 24.

  The resin molded body manufacturing system 100 shown in FIG. 1 can include an opening / closing mechanism (not shown) and a mold clamping mechanism (not shown). The opening / closing mechanism is configured to be able to open and close the mold 26 by horizontally moving the movable mold (here, the convex mold 24) so as to be in contact with and away from the fixed mold (here, the concave mold 22). On the other hand, the mold clamping mechanism is configured to fix the close concave mold 22 and the convex mold 24 in a tight state and hold the molding material in the cavity 38 in an injectable state.

  In the embodiment of the present invention, the concave mold 22 and the convex mold 24 can be made of a metal material or metal alloy material having rigidity and high thermal stability such as stainless steel. The push-up cores 28 and 30 and the open cores 32 and 34 can also be made of a metal material or metal alloy material having rigidity and high thermal stability such as stainless steel. The mold 24 may be the same material or different.

  The control unit 44 is, for example, a computer including a CPU that performs signal processing inside and a storage unit that stores programs and control data. Cylinder 20 or injection device, concave mold 22 and convex mold 24 (including temperature adjusting mechanism), push-up cores 28 and 30, open cores 32 and 34, hot air supply source and / or hot air supply means, opening / closing mechanism, and mold Each of the fastening mechanisms is connected to the control unit 44 and is configured to operate according to a command from the control unit 44. Further, an output signal of a temperature sensor (not shown) for detecting the temperature of the concave mold 22 and the convex mold 24 and the temperature of the molding material in the cylinder 20 is input to the control unit 44.

  With reference to FIGS. 1-3, an example of the manufacturing method of the pressure vessel 10 is demonstrated. First, the mold is clamped (S100), and then the molding material is injected (S102). As illustrated in FIG. 2A, a molding material 46 containing a thermoplastic resin and an elastomer is injected and filled into a cavity 38 formed between the concave mold 22 and the convex mold 24.

  In the embodiment, for example, nylon resin or polypropylene resin can be applied as the thermoplastic resin. The injection temperature from the nozzle 36 to the mold 26 when the nylon resin is applied can be, for example, about 250 ° C. to 300 ° C., and the injection temperature when the polypropylene resin is applied is, for example, about 200 ° C. to 250 ° C. However, the present invention is not limited to this. Moreover, although the temperature (mold temperature) of the concave mold 22 and the convex mold 24 can be set to a temperature that is higher by about several degrees C. to several tens of degrees C. than the mold temperature when the mold is opened, which will be described later, it is limited to this. It can be set as appropriate according to the injection temperature and molding time of the molding material.

  Moreover, the compounding quantity of the elastomer with respect to a molding material can be 5 mass%-30 mass%, More preferably, it can be about 10 mass%-20 mass%. When the amount of the elastomer is less than 5% by mass, the impact resistance may not be sufficient. Moreover, when the compounding quantity of an elastomer exceeds 30 mass%, malfunction may arise in gas barrier property depending on the kind of gas.

  Thereafter, the mold is cooled (S104), and then the mold is opened (S106). As the concave mold 22 and the convex mold 24 are cooled, the molding material 46 filled in the cavity 38 is solidified to form a molding intermediate 48. As illustrated in FIG. 2B, the convex mold 24 that is in close contact with the molding intermediate 48 is moved in the horizontal direction so as to be detached from the concave mold 22. In this Embodiment, the mold temperature at the time of mold opening can be about 50 to 80 degreeC, for example.

  Next, the molding intermediate 48 is released from the convex mold 24 (S108). As illustrated in FIG. 2C, by operating the push-up cores 28 and 30 and the open cores 32 and 34, more specifically, it contacts the forming intermediate body 48 formed in the vicinity of each core. The molding intermediate 48 can be released from the convex mold 24 by further pressing. In the embodiment, the distance between the end portion of the molding intermediate 48 and the contact surface 52 between the concave mold 22 formed on the convex mold 24 and released by the push-up cores 28 and 30 is about 10 mm. Can do. On the other hand, the distance between the central portion of the molding intermediate 48 and the convex mold 24, which is released by the open cores 32 and 34, is approximately 0.5 mm or less, more preferably about 0.2 mm to 0.3 mm. At this time, the space 54 formed between the convex mold 24 and the molding intermediate 48 is preferably maintained airtight, and in some cases, the open cores 32 and 34 can be made unnecessary.

  Next, warm air is supplied (S110). As illustrated in FIG. 2C, the hot air 50 flowing through the hot air supply passage 40 is supplied into a space 54 formed between the convex mold 24 and the molding intermediate 48. Circulate so that the internal temperature is substantially uniform. In the embodiment, for example, heated air can be used as the hot air 50, but as another embodiment, nitrogen, carbon dioxide, or the like may be used. The temperature of the hot air 50 can be at least higher than the temperature of the convex mold 24, and can be, for example, 100 ° C or higher, more specifically, about 120 ° C to 150 ° C. Moreover, although the air supply time of the warm air 50 depends on the mold temperature and the material of the molding intermediate 48, it can be, for example, about 2 to 3 minutes. If necessary, a hot air exhaust passage (not shown) for exhausting the hot air sent into the space 54 may be formed in the convex mold 24. The implementation of S110 may be started before the end of S108, and there may be overlapping times.

  Then, it is gradually cooled (S112). In the embodiment, the push-up cores 28 and 30 and the open cores 32 and 34 are returned to their original states (see FIG. 2B) and the convex mold 24 is moved so that the molding intermediate 48 is brought into close contact with the convex mold 24. Let According to the present embodiment, the warm air 50 in the space 54 can be quickly discharged, and can be cooled at a moderate speed similar to that of the convex mold 24. At this time, the time for cooling the molding intermediate 48 from the mold temperature (for example, 50 ° C.) to room temperature (for example, 25 ° C.) can be, for example, 1 minute to 30 minutes, but is not limited thereto. It can be changed according to the molding material and other various conditions.

  In S110, the molding intermediate 48 is heated with the warm air 50, and then gradually cooled in S112, so that crystals of the thermoplastic resin in at least a part of the molding intermediate 48, particularly in a portion in contact with the warm air 50, are obtained. The degree of gasification is further increased, and the gas barrier properties are improved.

  Finally, the resin molded body is taken out. As illustrated in FIG. 2D, the produced resin molded body 56 can be taken out of the system by further moving the convex mold 24 and / or by applying an ejector pin (not shown). When the produced resin molded body 56 is a liner constituent member, the liner 12 (see FIG. 4) can be produced by welding the molding end face. The produced liner 12 can be used for producing a pressure vessel 10 as shown in FIG. In the embodiment, for example, laser welding by a laser device set to a predetermined output condition is suitable for welding the resin molded body 56 or the liner constituent member. As other embodiments, vibration welding, ultrasonic welding, hot plate welding, or the like can be applied for welding.

  As described above, according to the embodiment of the present invention, a resin molded body having a high gas barrier property can be more easily produced as compared with the case where a conventional annealing process is applied, and production is also possible. Also improves. Moreover, even if it is a thickness comparable as the conventional resin molding, the resin molding which has high gas barrier property can be manufactured simply.

  1 is a so-called horizontal manufacturing system in which an injection device and a mold are arranged in a horizontal direction. As another embodiment, it may be a vertical manufacturing system in which a movable mold is moved downward from an injection apparatus disposed in the upper direction, and is more preferably a horizontal type from the viewpoint of capital investment. It is a manufacturing system.

  The present invention can be used for the production of a resin molded body containing a thermoplastic resin and an elastomer.

  The present invention can also be used for the production of FRP pressure vessels, such as hydrogen tanks.

  10 Pressure Vessel, 12 Liner, 14 Fiber Reinforced Resin Layer, 16 Base, 20 Cylinder, 22 Concave, 24 Convex, 26 Mold, 28, 30 Push-up Core, 32, 34 Open Core, 36 Nozzle, 38 Cavity, 40 Warm air supply passage, 42 sprue bush, 44 control unit, 46 molding material, 48 molding intermediate, 50 hot air, 52 abutment surface, 54 space, 56 resin molding, 100 production system.

Claims (6)

An injection step of injecting a molding material for producing the resin molded body into a cavity corresponding to the shape of the resin molded body to be formed, formed in a mold having a concave mold and a convex mold;
A mold cooling step of cooling the mold and forming a molding intermediate in which the molding material is solidified;
A mold opening step of opening the mold and detaching the convex mold in close contact with the molding intermediate from the concave mold;
A mold release step of releasing at least a part of the molding intermediate from the convex mold while maintaining airtightness between the convex mold and the molding intermediate;
Between the mold intermediate and the convex mold released from the mold, warm air having a temperature higher than the temperature of the convex mold to heat the molding intermediate;
A slow cooling step of slowly cooling the heated molding intermediate together with the convex mold;
Only containing the molding material comprises a thermoplastic resin and an elastomer, wherein the hot air air step and the annealing step, the resin molding, characterized in that for crystallizing at least a portion of the thermoplastic resin Body manufacturing method. The manufacturing method according to claim 1 ,
The thermoplastic resin is a nylon resin;
The method for producing a resin molded body, wherein the air supply temperature of the hot air is 100 ° C. or higher. A resin molded body produced by the production method according to claim 1 or 2 ,
The resin molded body is a liner constituting member constituting a pressure vessel for storing pressurized gas. A mold including a concave mold and a convex mold, and having a cavity corresponding to the shape of the resin molded body to be produced;
Injection means for injecting a molding material for producing the resin molded body in the cavity;
Mold cooling means for cooling the mold and forming a molding intermediate in which the molding material is solidified;
Mold opening means for opening at least one of the convex mold and the concave mold to detach the molding intermediate from the concave mold;
Mold release means for releasing at least a part of the molding intermediate from the convex mold while maintaining airtightness between the convex mold and the molding intermediate;
A hot air supply means for supplying hot air having a temperature higher than the temperature of the convex mold between the mold intermediate and the convex mold that have been released from the mold;
Wherein the molding material comprises a thermoplastic resin and an elastomer, wherein the hot air blowing means, the manufacturing system of the resin molding, wherein Rukoto at least some crystallized in the thermoplastic resin. A resin molded body produced by the production system according to claim 4 ,
The resin molded body is a liner constituting member constituting a pressure vessel for storing pressurized gas. A hollow liner,
A fiber reinforced resin layer covering the outer periphery of the liner;
Including
A pressure vessel, wherein the liner includes the resin molded body according to claim 3 or 5 .

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