JP2010264645A - Method and apparatus for molding foam resin molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively prevent the occurrence of local strength degradation in a foam resin molded article caused by swelling of a foaming cell in forming the foam resin molded article with molten foamable resin. <P>SOLUTION: A method and apparatus for molding a foam resin molded article includes a supply process for injecting to supply molten foamable resin 3 into a cavity 1 formed in a molding die 2; a flow process for allowing the molten foamable resin 3 to flow to substantially fill the cavity 1; a molding process for foaming and curing the molten foamable resin 3 substantially filled in the cavity 1, to form the foam resin molded article; and an ejection process for ejecting retention gas in a weld forming section 1a formed by the confluence of a plurality of molten foamable resin flows within the cavity 1, to the outside through an exhaust passage 19. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method and apparatus for molding a foamed resin molded product by injecting a melt-foamable resin into a cavity provided in a mold and forming a foamed resin molded product.

  Conventionally, for example, as shown in Patent Document 1 below, a melt-foamable resin containing a foaming agent is supplied in a sheet shot state into a cavity provided in a mold, that is, a melting amount smaller than the capacity of the cavity. A method of molding a foamed resin molded article configured to foam the resin in a cavity by injecting and supplying a foamable resin and then performing core back to move the mold in the mold opening direction is known. ing.

JP 2004-17285 A

  When injection of resin into the cavity of the mold is performed from a plurality of gates, or when an insert pin for branching the flow of molten resin is provided in the mold, a plurality of molten resin flows are formed in the cavity. It is known that a weld portion (weld line) in which the resin is fused by the merge is generated. And, when the weld part as described above occurs in the foamed resin molded product formed by the melt-foamable resin, the present inventors have a larger diameter of the foam cell in the weld part than the other parts, It has been found that the enlargement of the foamed cells tends to cause local strength reduction in the foamed resin molded product, and the tendency is more remarkable than that of the solid resin molded product.

  The present invention has been made in view of the above-mentioned problems, and the foamed cells are enlarged when the foamed resin molded product is formed from the melt-foamable resin. The object is to effectively prevent a reduction in strength.

  The invention according to claim 1 includes a supplying step of injecting and supplying a melt-foamable resin into a cavity formed in a mold, a fluidizing step of causing the melt-foamable resin to flow and substantially filling the cavity, A molding process for forming a foamed resin molded product by foaming and curing a melt-foamable resin substantially filled in the cavity, and a weld generating portion corresponding to a weld portion where a plurality of melt-foamable resin flows merge in the cavity And a discharge step of discharging the stagnant gas to the outside from the exhaust passage at least during the flow step.

  According to a second aspect of the present invention, in the method for molding a foamed resin molded article according to the first aspect, the stagnant gas in the weld generating part is sucked and discharged to the outside by the suction means connected to the exhaust passage. It is configured.

  The invention according to claim 3 is the method of molding a foamed resin molded product according to claim 1 or 2, wherein the retained gas is sucked by the suction means into the cavity in the supply step. Is configured to start immediately before reaching a position adjacent to the weld generating unit.

  According to a fourth aspect of the present invention, in the method for molding a foamed resin molded product according to any one of the first to third aspects, the molten moldable resin is foamed by core-backing the mold in the molding step. It is configured.

  According to a fifth aspect of the present invention, in the method for molding a foamed resin molded product according to any one of the first to fourth aspects, the molten foamable resin is injected into the cavity in a short shot state in the supplying step. It is comprised so that it may supply.

  The invention according to claim 6 has a molding die in which a cavity is formed, and supply means for injecting and supplying the molten foamable resin into the cavity of the molding die. A molding apparatus for a foamed resin molded product configured to form a foamed resin molded product by foaming and curing the melt-foamable resin substantially filled in the cavity and substantially filling the cavity, In the cavity, an exhaust passage for discharging the staying gas in the weld generating part corresponding to the weld part where a plurality of melt-foamable resin flows merge is provided.

  According to a seventh aspect of the invention, there is provided the foamed resin molded product molding apparatus according to the sixth aspect, further comprising suction means connected to the exhaust passage for sucking the staying gas in the weld generating part.

  According to an eighth aspect of the present invention, in the molding apparatus for a foamed resin molded product according to the sixth or seventh aspect, the molten foamable resin is supplied into the cavity in the supply step by suction of the staying gas by the suction means. Is provided with control means for controlling to start immediately before reaching the position adjacent to the weld generating unit.

  The invention according to claim 9 is the molding apparatus for the foamed resin molded product according to any one of claims 6 to 8, wherein the molten foamable resin is substantially filled in the cavity of the mold by the supply means. The mold is controlled so that the molten foamable resin is foamed by core-backing the mold.

  In the inventions according to claims 1 and 6, since the stagnant gas in the weld generating part is discharged to the outside from the exhaust passage, a foam cell is formed at the flow front part of the molten foamable resin injected into the cavity of the mold. Foaming cell enlargement in the weld part where gas aggregation is caused due to the occurrence of bubble breakage and the foamed cells tend to enlarge due to the joining of a plurality of melt-foamable resin flows in a high gas concentration state The foam cell diameter can be made uniform by suppressing the formation of the foamed resin, and a local decrease in strength due to the enlargement of the foam cell diameter of the weld portion is caused in the foamed resin molded product. There is an advantage that it can be effectively prevented by the configuration.

  In the inventions according to claims 2 and 7, since the stagnant gas in the weld generating part is sucked and discharged to the outside by the suction means connected to the exhaust passage, the stagnant gas in the weld generating part is the plural The expansion of the foam cell due to being entrained in the melt-foamable resin flow can be suppressed and the foam cell diameter can be made uniform, and the foam cell diameter of the weld portion is enlarged and the foam is expanded. There is an advantage that the occurrence of a situation in which the strength of the resin molded product is locally reduced can be effectively prevented with a simple configuration.

  In the invention according to Claims 3 and 8, the suction of the staying gas by the suction means is started immediately before the molten foamable resin supplied into the cavity reaches a position adjacent to the weld generating portion. Therefore, the air located in the weld portion in the cavity is excessively sucked, resulting in extremely low foamability in the weld portion, or excessive fluidity is imparted to the melt-foamable resin. It can be prevented from being led out to the exhaust passage, and the foamed resin molded product can be appropriately molded and the strength thereof can be homogenized as a whole.

  In the inventions according to claims 4 and 9, the molten foamable resin is supplied into the cavity of the mold and substantially filled, and then the melt foam is performed by performing core back for opening the mold in the molding step. The foaming resin is made to foam, so that a fine foam cell layer can be formed inside the foamed resin molded product, and the retained gas in the weld generating part is discharged from the exhaust passage to the outside, thereby foaming in the weld part. There is an advantage that the enlargement of the cell can be effectively suppressed.

  In the invention according to claim 5, since the melt-foamable resin is injected into the cavity and supplied in a short shot state, the melt-foamable resin can be reliably foamed, and the short-shot resin By controlling the state as necessary, the foaming rate of the foamed cell layer can be adjusted appropriately, and the expansion of the foamed cell diameter in the welded part occurs in response to the short shot. There is an advantage that the staying gas can be effectively suppressed by discharging the staying gas from the exhaust passage.

It is explanatory drawing which shows embodiment of the shaping | molding apparatus of the foamed resin molded product which concerns on this invention. It is a perspective view which shows an example of a foamed resin molded product. It is explanatory drawing which shows the example of formation of a weld part. It is explanatory drawing which shows the state which the foaming cell enlarged. It is a time chart which shows the molding process of a foamed resin molded product. It is process drawing which shows the 1st reference example of the shaping | molding method of a foamed resin molded product. It is process drawing which shows the 2nd reference example of the molding method of a foamed resin molded product.

  FIG. 1 shows a first embodiment of a molding apparatus for a foamed resin molded product according to the present invention. The molding apparatus for the foamed resin molded product includes a molding die 2 in which a cavity 1 is provided, a supply unit 4 for injecting and supplying a melt-foamable resin 3 into the cavity 1 of the molding die 2, and the molding described above. A suction means 5 for sucking and discharging the staying gas in a portion (the following weld generating portion 1a) where a plurality of melt-foamable resin flows merge in the mold 2, and a control for controlling the supply means 4 and the suction means 5 Means 6 are provided.

  Then, the molten foamable resin 3 supplied from the supply means 4 to the mold 2 is caused to flow to substantially fill the cavity 1, and the molten foamable resin 3 substantially filled in the cavity 1 is foamed and cured. And by operating the suction means 5 at a predetermined timing, the staying gas located in the weld generating part 1a in the cavity 1 is sucked and discharged to the outside, while being used for automobiles, building materials, household appliances or It is comprised so that the foamed resin molded product used for daily miscellaneous goods etc. may be formed.

  FIG. 2 shows an example of a foamed resin molded product 7 molded by the molding apparatus. The foamed resin molded product 7 has a semi-cylindrical portion 8 having a predetermined length and flange portions 9 provided on both sides thereof, and is not shown in the figure corresponding to the foamed resin molded product 7. It is a duct member which comprises a duct of an air-conditioner for vehicles by being combined with goods. The flange portion 9 of the foamed resin molded product 7 is formed with through holes 10 and 11 used for mounting or positioning of the foamed resin molded product 7. In FIG. 2, reference numerals 12 a and 12 a denote resin supply portions corresponding to the positions of the gates 12 and 12 provided in the mold 2, and reference numeral 13 denotes a supply from the gates 12 and 12 into the cavity 1. The weld part produced | generated by the said foamed resin molded product 7 by the several melt-foamable resin flow which consists of the made melt-foamable resin 3 joins is shown.

  In the present embodiment, two melt-foamable resin flows are formed by injecting the melt-foamable resin 3 into the cavity 1 from a pair of gates 12, 12 provided in the mold 2. It is like that. Accordingly, the two melt-foamable resin flows merge at a substantially central position of the resin supply portions 12a, 12a corresponding to the two gates 12, 12, that is, a central position in the length direction of the foamed resin molded product 7. A welded weld 13 is produced. In addition, since two melt-foamable resin flows are formed along the insert pin in the installation portion such as the insert pin disposed in the cavity 1 in order to form the through holes 10 and 11, Weld portions 13a and 13b are also generated at the junction.

  As shown in FIG. 3, the weld portion 13 has an area of about 10% to 30% of the foamed resin molded product 7. Due to the enlargement of the foamed cells in the weld portion 13, the strength tends to decrease. That is, as shown in FIG. 4, gas flow caused by foam cell breakage occurs at the flow front end of the molten foamable resin 3 injected into the cavity 1 from the gates 12, 12 of the mold 2. Aggregation is likely to occur, and a plurality of melt-foamable resin flows join together in the weld portion 13 in a state where the gas concentration is high, so that the foam cells tend to be enlarged compared to the peripheral portion. The resin density is insufficient, and it tends to be difficult to ensure sufficient strength. In FIG. 4, reference numeral 7 a denotes a skin layer formed by cooling the melt-foamable resin 3 or the like at an early stage.

  As shown in FIG. 1, the molding die 2 includes a fixed die 14 supported in a fixed state by a support means (not shown), and a movable die 15 supported so as to be relatively movable with respect to the fixed die 14. The fixed mold 14 and the movable mold 15 are respectively provided with corresponding concave portions 16 and convex portions 17. Then, by inserting the convex portion 17 of the movable die 15 into the concave portion 16 of the fixed die 14, the cavity 1 is partitioned and formed therebetween.

  The fixed mold 14 of the mold 2 is formed with a resin introduction passage 18 into which the melt-foamable resin 3 injected from the supply means 4 is introduced, and the downstream side portion of the resin introduction passage 18 is moved up and down. The gates 12 and 12 branched from each other are provided. Further, the fixed die 14 is formed with an exhaust passage 19 for discharging the staying gas of the weld generating portion 1a located in the vicinity of the center of the cavity 1 corresponding to the generating position of the weld portion 13, that is, in the vicinity of the central portion in the vertical direction of the cavity 1, A suction pipe 20 of the suction means 5 is connected to the exhaust passage 19.

  The supply means 4 includes a cylindrical injection cylinder 21, a screw 22 disposed in the injection cylinder 21 and supported so as to be rotatable and movable back and forth, and a drive for rotating and driving the screw 22 forward and backward. And a mechanism 23. A hopper 24 for introducing resin pellets P made of, for example, polypropylene, polyethylene, polystyrene, or the like is installed on the rear upper part of the injection cylinder 21, and the peripheral wall portion of the injection cylinder 21 is supplied from the hopper 24. A heater (not shown) for heating and melting the resin pellets P is installed. In addition, a supercritical fluid composed of nitrogen, carbon dioxide, etc. in a supercritical state (a state exceeding the critical pressure and critical temperature) generated in the supercritical fluid supply device 25 is provided at a substantially central portion in the longitudinal direction of the injection cylinder 21. An injection nozzle 26 for injecting the liquid into the injection cylinder 21 is connected.

  The molten resin generated by the resin pellet P charged into the injection cylinder 21 being melted in response to the heat of the heater and the supercritical fluid injected from the injection nozzle 26 are the screw. The melt-foamable resin 3 is formed by mixing in accordance with the rotation of 22, and the supercritical fluid is vaporized when the foamed resin-molded product 7 is molded, so that the melt-foamable resin 3 is foamed. That is, in this embodiment, by using a physical foaming agent made of a supercritical fluid as the foaming agent of the melt-foamable resin 3, it has both viscosity and dissolving power as a liquid and intense molecular mobility as a gas. It is configured to perform ultrafine foam molding utilizing the properties of the supercritical fluid.

  The melt-foamable resin 3 in the injection cylinder 21 is pushed out to the front side of the injection cylinder 21 according to the rotation of the screw 22. The screw 22 is retracted by the reaction force, and the rotation of the screw 22 is stopped when the retracted amount of the screw 22 reaches a distance corresponding to the injection amount of the melt-foamable resin 3. Thereafter, the screw 22 is advanced at a high speed by the drive mechanism 23, whereby the foam 22 is melted and foamed into the cavity 1 from the tip nozzle 27 provided in the front portion of the injection cylinder 21 through the resin introduction passage 18 of the fixed mold 14. Resin 3 is injected.

  The suction means 5 has a suction pipe 20 having an on-off valve 28, a negative pressure generating chamber 29, and a vacuum pump 30 for sucking air in the chamber 29, and is output from the control means 6. According to the control signal, at least during the flow process of the melt-foamable resin 3, the stay gas in the weld generating part 1a is discharged from the exhaust passage 19 to the outside. In the first embodiment, when the molten foamable resin 3 supplied into the cavity 1 from the supply means 4 reaches a position adjacent to the weld generating portion 1a, for example, the filling amount of the molten foamable resin 3 is the cavity. The vacuum pump 30 of the suction means 5 is operated during a period from the time when the melted foamable resin 3 is approximately filled in the cavity 1 until the melted foamable resin 3 is substantially filled in the cavity 1. The gas staying in the weld generator 1a is discharged from the exhaust passage 19 to the outside.

  Next, a method for molding the foamed resin molded product 7 using the molding apparatus will be described with reference to the timing chart shown in FIG. First, by opening the mold 2 at the start time T0 of the molding cycle, the movable mold 15 is driven at a time T1 after a predetermined time has elapsed after the foamed resin molded product 7 formed in the previous molding cycle is taken out. Then, mold clamping is started. For example, at a predetermined time T2 after about 5 seconds have elapsed from the mold clamping start time T1 and the mold clamping operation is completed, the screw 22 of the supply means 4 is advanced at a high speed to melt and foam the inside of the injection cylinder 21. Injection of the resin 3 from the tip nozzle 27 to the resin introduction passage 18 of the mold 2 is started, and the molten foamable resin 3 is supplied into the cavity 1 through the gates 12 and 12.

  By setting the supply amount of the melt-foamable resin 3 to be smaller than the capacity of the cavity 1, the melt-foamable resin 3 is fed into the cavity 1 in a so-called short shot state. The injection completion time point T3 of the resin 3 is set. A period from the injection start time T2 to the injection completion time T3 of the melt-foamable resin 3 is a supply process for injecting and supplying the melt-foamable resin 3 into the cavity 1 formed in the molding die 2. The time is set to about 2 seconds, for example.

  The mold 2 is held in a closed state until a delay time of, for example, about 1 sec elapses after the completion of the injection of the melt-foamable resin 3, for example, about 1 sec. It becomes a fluid process to fill. Then, at the time T4 when the delay time (flowing process time) ends, the core back for moving the movable mold 15 of the mold 2 in the mold opening direction is started, so that the melt foamability substantially filled in the cavity 1 is obtained. The resin 3 is foamed and cured to form a foamed resin molded product 7 (molding process). For example, when the molding process time set to about 1 second has elapsed from the start time T4 of the core back, for example, the core back operation is finished, and then at a time T6 when a predetermined time has elapsed, the mold 2 is moved. The mold is opened and the foamed resin molded product 7 is taken out.

  Further, in the course of the supply step of supplying the melt-foamable resin 3 into the cavity 1 by the supply means 4, the weld generating section is formed by the suction means 5 at a predetermined timing before the melt-foamable resin 3 is cured. The accumulated gas 1a is discharged from the exhaust passage 19 to the outside. For example, when the supply process time is set to about 2 sec, about 0.5 sec to 1.5 sec elapses from the injection start time T2 of the melt-foamable resin 3, and the inside of the cavity 1 is supplied in the supply process. At the time T21 when the melt-foamable resin 3 supplied to the gas reaches the position adjacent to the weld generating part 1a, the open / close valve 28 is opened and the vacuum pump 30 of the suction means 5 is operated, whereby the weld generating part 1a. The remaining gas is controlled to be led out from the exhaust passage 19 to the suction pipe 20 and the negative pressure generating chamber 29.

  Then, for example, by stopping the operation of the vacuum pump 30 at a time T32 immediately before the end time T4 of the flow process, the staying gas discharging process using the suction means 5 is completed. Note that the end time T32 of the exhaust stroke may be set to a time corresponding to the end time T5 of the molding process, or set to a predetermined time from the end time T4 of the flow process to the end time T5 of the molding process. May be.

  As described above, the mold 2 having the cavity 1 formed therein and the supply means 4 for injecting and supplying the melt-foamable resin 3 into the cavity 1 of the mold 2 are provided. 3 is made to flow and substantially fill in the cavity 1, and the foamed resin molded product 7 is formed by foaming and curing the molten foamable resin 3 substantially filled in the cavity 1. 7 and a molding method using the molding apparatus, a weld portion where a plurality of melt-foamable resin streams formed by supplying the melt-foamable resin 3 into the cavity 1 of the mold 2 join together. 13, the staying gas in the weld generating portion 1 a corresponding to 13 is discharged to the outside from the exhaust passage 19 at least during the above-described flow process. Therefore, when the foamed resin molded product 7 is formed, foaming is performed. Le is the advantage that a local reduction in strength due to enlargement can be prevented from occurring in the resin foam product 7 effectively.

  That is, in the first embodiment, the gas aggregation caused by foam cell breakage occurs at the flow front end portion of the molten foamable resin 3 injected into the cavity 1 from the gates 12 and 12 of the mold 2. It is generated and a plurality of melt-foamable resin flows join together in a state where the gas concentration is high, so that the stagnant gas in the weld generating part 1a that tends to enlarge the foam cell is sucked and discharged to the outside from the exhaust passage 19 Since the suction means 5 is provided and the suction means 5 is operated at least during the flow step to forcibly discharge the staying gas to the outside, the staying gas in the weld generating unit 1a is used as the plurality of molten foams. The foamed cell diameter can be made uniform by suppressing the enlargement of the foamed cell due to being caught in the conductive resin flow. Therefore, it is possible to effectively prevent the occurrence of a situation in which the strength of the foamed resin molded product 7 is locally reduced due to enlargement of the foam cell diameter of the weld portion 13 with a simple configuration. There is.

  In the first embodiment, the suction of the staying gas by the suction means 5 is performed at a position where the melt foamable resin 3 supplied into the cavity in the melt foamable resin 3 supplying step is adjacent to the weld generating portion 1a. Since it is configured to start at the time T31 immediately before reaching, the foamability in the weld portion 13 is extremely reduced due to excessive suction of the air located in the weld portion 13 in the cavity 1. Further, it is possible to prevent the molten foamable resin 3 from being excessively fluidized and led to the exhaust passage 19. Therefore, there is an advantage that the foamed resin molded product 7 can be properly molded and the strength thereof can be homogenized as a whole.

  Further, as shown in the first embodiment, the melt-foamable resin 3 supplied into the cavity 1 from the supply means 4 is substantially filled in the cavity 1 of the mold in the flow step, and then molded in the molding step. When the molten foamable resin 3 is configured to be foamed by performing a core back for moving the movable mold 15 of the mold 2 in the mold opening direction, a fine foamed cell layer is formed inside the foamed resin molded product 7. While being able to form, the foaming rate of the said foaming cell layer can be adjusted appropriately by controlling the said core back timing and core back amount as needed.

  Moreover, when the melt-foamable resin 3 is positively foamed by the core back, enlargement of the foamed cell diameter in the weld portion 13 tends to be noticeably prone to occur. Further, the suction of the staying gas located in the weld generating part 1a in the cavity 1 by the suction means 5 and discharging it to the outside can effectively suppress the expansion of the foamed cells in the weld portion 13. For this reason, the foamed resin molding having uniform-sized foam cells while effectively preventing the occurrence of a situation where the strength is locally reduced due to enlargement of the foam cell diameter, with a simple configuration There is an advantage that the product 7 can be formed.

  Moreover, in the said embodiment, since it comprised so that the said melt-foamable resin 3 was inject | poured and supplied in the state of the short shot in the cavity 1 by the supply means 4, the said melt-foamable resin 3 can be made to foam reliably. In addition, by controlling the state of the short shot as necessary, the foaming rate of the foamed cell layer can be adjusted appropriately, and the stagnant gas located in the weld generating part 1a in the cavity 1 by the suction means 5 By sucking and discharging to the outside, there is an advantage that enlargement of the foamed cell diameter corresponding to the short shot can be effectively suppressed. Therefore, the foamed resin molded article 7 having uniform-sized foam cells is formed while effectively preventing the local strength reduction caused by the enlargement of the foam cell diameters with a simple configuration. can do.

  Instead of the first embodiment in which the staying gas in the weld generating unit 1a is sucked and discharged to the outside by the suction means 5 connected to the exhaust passage 19, the staying gas can be discharged. A gas vent part (exhaust passage) 31 composed of fine slits capable of regulating the discharge of the melt-foamable resin 3 is provided in the fixed mold 14 and the movable mold 15 of the mold 2 and supplied into the cavity 1 of the mold 2 The retained gas in the weld generating part 1a is led out into the gas vent part 31 in accordance with the flow pressure of the melted foamable resin 3, and the retained gas in the weld generating part 1a is discharged to the outside. May be. In this case, there is an advantage that it is possible to effectively prevent the local decrease in strength in the foamed resin molded product 7 by suppressing the enlargement of the foamed cells in the weld portion 13 with a simple configuration. .

  FIG. 6 shows a first reference example of a molding method for forming the foamed resin molded product 7. According to the first reference example, the pair of jump bases 32 and 33 for displacing the pair of melt-foamable resin flows 3a and 3b that have reached the position in the vicinity of the weld generator 1a in opposite directions are provided on the weld generator 1a. By being installed so as to be able to move in and out, the contact surfaces of the both melt-foamable resin flows 3a and 3b are formed obliquely, and the strength reduction due to the enlargement of the foamed cells is caused by the welded foam 7 There is an advantage that it can be prevented from occurring in the portion 13.

  That is, in the first reference example, as shown in FIG. 6A, when the molten foamable resin 3 is injected into the cavity 1, the jump tables 32 and 33 are held in a state of protruding into the weld generating portion 1a. By doing so, as shown in FIG. 6B, one molten foamable resin stream 3a is obliquely displaced from the movable mold 15 side to the fixed mold 14 side, and the other molten foamable resin stream 3b is fixed to the fixed mold. It is displaced obliquely from the 14 side to the movable mold 15 side. As shown in FIG. 8 (c), when the melt-foamable resin flows 3a and 3b pass through the installation portions of the jump tables 32 and 33, the jump tables 32 and 33 are welded by driving means outside the figure. It is made to evacuate outside the production | generation part 1a. When the both melt-foamable resin flows 3a and 3b are displaced in the opposite directions to make the both abut abutment surfaces in this way, the residence gas located in the weld generating portion 1a is widened. Since it can be dispersed over the area, it is possible to prevent the enlarged foam cells S from concentrating on the weld portion 13 of the foamed resin molded product 7 and to effectively prevent the local strength reduction. It is.

  Instead of the first reference example in which the pair of jump tables 32 and 33 are installed so as to be able to appear and retract in the weld generating unit 1a, as in the second reference example shown in FIGS. 7 (a) to (c), The fixed mold 14 is provided with a mirror surface portion 34 for promoting the flow of the first melt-foamable resin flow 3a, and the rough polishing portion 35 for imparting a flow resistance to the first melt-foamable resin flow 3a is provided for the movable die 15. As a result, the flow rate of the first melt-foamable resin flow 3a positioned on the fixed mold 14 side is increased as compared with that on the movable mold 15 side, and the mirror surface portion 36 that promotes the flow of the second melt-foamable resin flow 3b is moved. 15 and a rough polishing portion 37 that provides flow resistance to the second melt-foamable resin flow 3b is provided in the fixed mold 14 so that the flow velocity of the second melt-foamable resin stream 3b located on the movable mold 15 side is provided. To increase compared to the fixed mold 14 side It may form. When configured in this way, both the melt-foamable resin flows 3a and 3b are displaced in opposite directions and are brought into contact with each other obliquely, thereby making the configuration simpler than that of the first reference example. It is possible to prevent the enlarged foam cells S from concentrating on the weld portion 13 of the foamed resin molded product 7 and to effectively prevent a local strength reduction from occurring in the foamed resin molded product 7 accordingly. it can.

  Further, a vibrator for imparting vibration is provided to the weld generating portion 1a of the cavity 1, and the vibrator is operated at least during the flow process of the molten foamable resin 3, thereby generating the weld portion 13 of the foamed resin molded product 7. You may comprise so that the made foam cell may be subdivided. According to this configuration, there is an advantage that it is possible to effectively prevent the foamed resin molded product 7 from being locally weakened by suppressing the enlargement of the foamed cells in the weld portion 13.

  Further, a protrusion made of a pin or the like for generating a turbulent flow corresponding to the melt-foamable resin flow 3a, 3b that has reached a position in the vicinity of the weld generating portion 1a is projected into the cavity 1, thereby providing a weld portion 13 You may comprise so that the foam cell may be subdivided. Even in this configuration, it is possible to effectively prevent the foamed resin molded product 7 from being locally reduced in strength due to the enlargement of the foamed cells in the weld portion 13. In addition, it is preferable to provide a driving means for driving the protrusion so that it protrudes in and out of the cavity 1 so that the protrusion is retracted out of the cavity 1 after the cavity 1 is filled with the molten foamable resin 3.

DESCRIPTION OF SYMBOLS 1 Cavity 1a Weld production | generation part 2 Molding die 3 Melt foamable resin 4 Supply means 5 Suction means 6 Control means 7 Foamed resin molded product 13 Weld part 19 Exhaust passage

Claims (9)

  Supply step of injecting and supplying molten foamable resin into the cavity formed in the mold, fluidizing step of flowing the molten foamable resin into the cavity and substantially filling the cavity, and melting substantially filled in the cavity A foaming resin is foamed and cured to form a foamed resin molded product, and at least the flow of the staying gas in the weld generating part corresponding to the weld part where a plurality of melt-foamable resin flows merge in the cavity A method for molding a foamed resin molded product comprising a discharging step of discharging the exhaust passage to the outside during the step.   2. The method for molding a foamed resin molded article according to claim 1, wherein the staying gas in the weld generating part is sucked and discharged to the outside by suction means connected to the exhaust passage.   The suction of the staying gas by the suction means is configured to start immediately before the melt-foamable resin supplied into the cavity in the supply step reaches a position adjacent to the weld generating unit. A method for molding a foamed resin molded article according to claim 1 or 2.   The method for molding a foamed resin molded article according to any one of claims 1 to 3, wherein the molding die is core-backed in the molding step to foam the melt-foamable resin.   The molding of the foamed resin molded product according to any one of claims 1 to 4, wherein the melt-foamable resin is injected and supplied in a short shot state into the cavity in the supplying step. Method.   It has a mold having a cavity formed therein, and a supply means for injecting and supplying the melt-foamable resin into the cavity of the mold, and the melt-foamable resin is made to flow to substantially fill the cavity. And a foamed resin molded product molding apparatus configured to form a foamed resin molded product by foaming and curing a melt-foamable resin substantially filled in the cavity, wherein a plurality of melt-foamed products are formed in the cavity. An apparatus for molding a foamed resin molded product, comprising an exhaust passage for discharging a staying gas in a weld generating portion corresponding to a weld portion where a functional resin flow merges.   The molding apparatus for a foamed resin molded product according to claim 6, further comprising suction means connected to the exhaust passage for sucking a staying gas in the weld generating part.   Control means is provided for controlling the suction of the staying gas by the suction means so as to start immediately before the molten foamable resin supplied into the cavity in the supply step reaches a position adjacent to the weld generating portion. The molding apparatus for a foamed resin molded product according to claim 6 or 7,   9. The method according to claim 6, wherein after the molten foamable resin is substantially filled in the cavity of the mold by the supplying means, the mold is core-backed to foam the molten foamable resin. An apparatus for molding a foamed resin molded article according to claim 1.

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