JP2010264646A - 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 the 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 a cooling process for cooling a formed section of a weld portion 13 where a plurality of molten foamable resin flows join within the cavity 1, to a lower temperature than other portions during the molding process at least. <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, At least a forming step of forming a foamed resin molded product by foaming and curing the melt-foamable resin substantially filled in the cavity, and a weld portion generating portion where a plurality of melt-foamable resin flows merge in the cavity, And a cooling step for cooling to a lower temperature than other portions during the molding 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, in the cooling step, the cavity surface located at the generating portion of the weld portion is cooled to a lower temperature than other portions. It is comprised so that it may do.

  According to a third aspect of the present invention, in the method for molding a foamed resin molded product according to the second aspect, the step of supplying the melt-foamable resin is completed for cooling the cavity surface located at the generating portion of the weld portion. It will start later.

  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, It is provided with a cooling means for cooling a welded portion where a plurality of melt-foamable resin flows merge in the cavity to a temperature lower than other portions during foaming and curing of the melt-foamable resin. is there.

  The invention according to claim 7 is the molding apparatus for the foamed resin molded product according to claim 6, wherein the cooling means cools the cavity surface located at the generating portion of the weld portion to a lower temperature than other portions. It is comprised so that it may do.

  The invention according to claim 8 is the molding apparatus for a foamed resin molded product according to claim 7, wherein the cooling of the cavity surface by the cooling means is started after the supply of the melt-foamable resin to the cavity is completed. Control means for controlling is provided.

  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 core-backed to foam the melt-foamable resin.

  In the inventions according to claims 1 and 6, since the formation portion of the weld portion where a plurality of melt-foamable resin flows merge in the cavity is configured to be cooled to a temperature lower than that of other portions at least during the molding step. , A plurality of melt-foamable resin flows in a state where gas aggregation occurs due to foam breakage of foam cells at the flow front of the melt-foamable resin injected into the mold cavity and the gas concentration is high Can form a thick skin layer in the weld part where the foam cells tend to be enlarged due to the joining of the foam cells, and the foam cell diameter of the weld part is thereby enlarged. There is an advantage that local strength reduction can be effectively prevented with a simple structure.

  In the inventions according to Claims 2 and 7, since the cavity surface located in the generating portion of the weld portion is cooled and the temperature thereof is set to be lower than that of other portions, the surface of the weld portion can be formed with a simple configuration. It is possible to suppress the foaming at the part and form a thick skin layer located in the part, and thereby, it is possible to more effectively prevent the local strength decrease in the foamed resin molded product. is there.

  In the invention according to claims 3 and 8, since the cooling of the cavity surface is started after the supply of the melt-foamable resin to the cavity is finished, the cavity surface is kept until the supply of the melt-foamable resin is finished. It is possible to maintain the temperature of the molten foamable resin higher than that during the cooling step, and supply and fill the molten foamable resin to the cavity while preventing a decrease in fluidity due to a temperature drop of the molten foamable resin. Can be carried out easily and appropriately.

  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. Since the foaming resin is configured to be foamed, a fine foam cell layer can be reliably formed inside the foamed resin molded product, and at the same time, the welded portion is formed at a lower temperature than other parts during the molding process. By cooling, there is an advantage that it is possible to effectively prevent a local decrease in strength from occurring in the foamed resin molded product due to the formation of enlarged foam cells in the inner portion of the weld portion. .

  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 at the same time, the generation part of the weld part is cooled to a lower temperature than other parts at least during the molding step. There is an advantage that it is possible to effectively prevent a local decrease in strength in the foamed resin molded product due to the formation of enlarged foam cells in the inner part of the weld portion.

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 explanatory drawing which shows the formation state of a skin layer. It is explanatory drawing which shows another embodiment of the shaping | molding method of the foamed resin molded product which concerns on this invention. It is explanatory drawing which shows the reference example of the molding method of a foamed resin molded product.

  FIG. 1 shows an 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 temperature adjusting device 5 that adjusts the temperature of the cavity surface 1a located at a portion where a plurality of melt-foamable resin flows merge in the mold 2 (a generating portion of the weld portion 13 below), the supply means 4 and the temperature adjusting device 5 And control means 6 for controlling.

  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. In addition, by operating the temperature control device 5 at a predetermined timing, the cavity surface 1a located in the weld portion 13 is cooled to a temperature lower than that of other portions, while being used for automobiles, building materials, household appliances, or Japan. It is configured to form a foamed resin molded product used for household goods.

  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. If enlargement of the foamed cell occurs in the inner portion of the weld portion 13, the strength of the foamed resin molded product 7 may partially 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.

  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. Furthermore, the fixed mold 14 and the movable mold 15 include hot water for adjusting the temperature of the cavity surface located in the generating portion of the weld portion 13, that is, the cavity surface 1 a located near the vertical center of the cavity 1. Alternatively, water passages 19 through which cold water circulates are formed.

  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 temperature adjusting device 5 that adjusts the temperature of the cavity surface 1 a located at the generating portion of the weld portion 13 where a plurality of melt-foamable resin flows merge in the cavity 1 is a heating means 28 that supplies hot water to the water passage 19. And a cooling means 29 for supplying cold water to the water passage 19, and hot water supplied from the heating means 28 via the hot water passage 30 or cold water supplied from the cooling means 29 via the cold water passage 31. The selector valve 32 and the water supply passage 33 that select one of them and supplies it to the water passage 19 and the drainage discharged from the water passage 19 are selected for the return passage 34 of the heating means 28 or the return passage 35 of the cooling means 29. A circulation passage 36 and a switching valve 37 are provided for circulation.

  Hot water heated to a predetermined temperature in the heating means 28 is supplied to the water passage 19 through the hot water passage 30, the switching valve 32, and the water supply passage 33, and the circulation passage 36, the switching valve 37, and the return passage 34. The hot water having a predetermined temperature is continuously supplied to the water passage 19 by being circulated through the heating means 28 through the heating means 28, and the cavity surface 1a located at the generating portion of the weld portion 13 is heated to a temperature of about 60 °, for example. It has come to be. By switching the switching valves 32 and 37 from this state, the cold water cooled to a predetermined temperature in the cooling means 29 is supplied to the water passage 19 through the cold water passage 31, the switching valve 32 and the water supply passage 33. At the same time, the water is circulated to the cooling means 29 through the circulation passage 36, the switching valve 37, and the return passage 35, whereby cold water having a predetermined temperature is continuously supplied to the water passage 19 so that the cavity surface 1a has, for example, 30 It is cooled to a temperature of about °.

  In this embodiment, hot water heated by the heating means 28 is passed near the weld portion 13 during the following supply process for supplying the melt-foamable resin 3 into the cavity 1 from the supply means 4. Supply to the water channel 19 to heat the cavity surface 1a, and flow the molten foamable resin 3 to substantially fill the cavity 1, and the foamed resin is molded by foaming and curing the molten foamable resin 3. During the following molding process for forming the product 7, the control means controls the cooling of the cavity surface 1a located in the generating portion of the weld portion 13 by supplying the cold water cooled by the cooling means 29 to the water passage 19 6 to execute.

  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. The 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 mold 2.

  The mold 2 is held in a closed state until a predetermined delay time elapses after the completion of injection of the melt-foamable resin 3 until a predetermined delay time elapses. During this time, the melt-foamable resin 3 flows to substantially fill the cavity 1. It becomes a flow process. Then, at the time T4 when the flow process is completed, the core back for moving the movable mold 15 of the mold 2 in the mold opening direction is started, so that the molten foamable resin 3 substantially filled in the cavity 1 is expanded and Curing is performed to form the foamed resin molded product 7 (molding step). The core back operation is finished at a time T5 when the molding process is finished after a predetermined time has elapsed from the start time T4 of the core back, and then the mold 2 is opened at a time T6 when the predetermined time has passed. Then, the foaming resin molded product 7 is taken out.

  Further, at the start time T0 of the molding cycle, temperature adjustment in a heating process in which hot water of a predetermined temperature is supplied from the heating means 28 to the water passage 19 to heat the cavity surface 1a located in the generation part of the weld portion 13 is performed. By executing the control, the cavity surface 1a that was at room temperature before starting the molding operation of the foamed resin molded product 7 is raised to, for example, about 60 ° C., as shown by the broken line in FIG. The state is maintained until time T3 when the supply process of the melt-foamable resin 3 is completed. The temperature (60 ° C.) of the cavity surface 1 a adjusted by the heating means 28 is provided at a location located in the cavity 1 other than the vicinity of the weld portion 13 where a plurality of molten foamable resin flows merge. The heating temperature is set to be about the same as the heating temperature of a portion located outside the vicinity of the weld portion 13 heated by supplying warm water or steam to the heating path 38 (see FIG. 6).

  Then, at the time T3 when the supply step of the melt-foamable resin 3 is finished, the temperature adjustment of the heating step is finished, and cold water at a predetermined temperature is supplied from the cooling means 29 to the water passage 19, whereby the weld portion The process proceeds to the temperature adjustment control state of the cooling process for cooling the cavity surface 1a located in the 13 generation section, and at least during the molding process of the foamed resin molded product 7, a plurality of melt-foamable resin flows merge in the cavity 1. The temperature of the cavity surface 1a located in the weld portion 13 is cooled to a temperature lower than other portions, for example, about 30 ° C.

  The temperature adjustment in the cooling process ends at time T5 when the molding process of the foamed resin molded article 7 is completed, and the warm water of the heating means 28 is supplied to the water channel 19 from this time T5, thereby generating the weld portion 13. Transition to the temperature adjustment control state of the heating process for heating the cavity surface 1a located in the part, and maintain the temperature adjustment control state of the heating process until time T3 when the temperature adjustment control of the cooling process is started in the next molding cycle To do.

  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. Since the 13 generation parts are configured to be cooled to a temperature lower than that of other parts at least during the molding process of the foamed resin molded product 7, the foamed cells are fertilized when the foamed resin molded product 7 is formed. Local intensity reduction due to reduction is advantageous in that from occurring in the resin foam product 7 can be prevented effectively.

  In other words, as shown in the above embodiment, when the molten foamable resin 3 is injected and supplied into the cavity 1 from the plurality of gates 12, 12 provided in the mold 2, the flow front end portion thereof As a result, gas bubbles are caused by foam breakage of the foam cells, and the foam cells tend to enlarge due to the joining of a plurality of melt-foamable resin flows in a high gas concentration. There is a tendency that the strength of the foamed resin molded product 7 is locally reduced due to the insufficient amount of resin filling in the portion where the occurrence of the resin occurs.

  However, as described above, the temperature of the weld portion 13 where a plurality of melt-foamable resin flows merge in the cavity 1 is molded so that at least the melt-foamable resin 3 is foamed and cured to form the foamed resin molded product 7. In the case where it is configured to cool to a lower temperature than other parts during the process, as shown in FIG. 6, the foaming in the surface portion of the weld portion 13 is suppressed, and the skin layer 7a made of a fine foam layer is formed. It can be partially thick. Therefore, the strength reduction of the foamed resin molded product 7 due to the formation of the enlarged foam cell 7b in the inner portion of the weld portion 13 can be compensated by increasing the thickness of the skin layer 7a. Thus, there is an advantage that the strength of the foamed resin molded product 7 can be made uniform as a whole.

  In particular, as shown in the embodiment, by supplying cooling water from the cooling means 29 to the water passage 19 formed in the vicinity of the cavity surface 1a located in the generating portion of the weld portion 13, the cavity surface 1a is When it is configured to cool and set the temperature of the weld portion 13 to be lower than that of other portions, foaming on the surface portion of the weld portion 13 can be effectively suppressed with a simple configuration. Therefore, when the skin layer 7a of the weld portion 13 is formed thick, the expanded foam cell 7b is formed on the inner portion thereof, and the strength of the foamed resin molded product 7 is partially reduced. There is an advantage that it can be effectively prevented from occurring.

  In the above embodiment, the temperature of the cavity surface 1a is maintained at a temperature higher than that during temperature adjustment in the cooling step until the supply of the melt-foamable resin 3 to the cavity 1 is completed, and the melt-foamability to the cavity 1 is maintained. Since the cooling means 29 starts cooling the cavity surface 1a after the supply of the resin 3 is completed, the molten foamable resin 3 is injected when the molten foamable resin 3 is injected into the cavity 1 and supplied. 3 can be prevented from decreasing. Accordingly, it is possible to smoothly supply and fill the melt-foamable resin 3 into the cavity 1 while maintaining the fluidity of the melt-foamable resin 3 in a good state.

  Further, as shown in the above embodiment, the melt-foamable resin 3 supplied from the supply means 4 into the cavity 1 is substantially filled in the cavity 1 of the mold in the flow step, and then the mold 2 in the molding step. When the molten foamable resin 3 is foamed by performing a core back that moves the movable mold 15 in the mold opening direction, a fine foam cell is formed inside the foamed resin molded product 7. In addition, the foaming rate of the foamed cell layer can be appropriately adjusted by controlling the core back timing and the core back amount as necessary.

  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. In the cooling process, the weld portion 13 in the cavity 1 is cooled to suppress foaming on the surface portion of the portion, and the skin layer 7a is formed thick, so that the inner portion of the weld portion 13 is enlarged. There is an advantage that it is possible to effectively prevent a decrease in strength due to the formation of the expanded cell 7b in the expanded resin molded product 7.

  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, it is possible to appropriately adjust the foaming rate of the foamed cell layer, and by cooling the weld portion 13 in the cavity 1 in the cooling step, the above-mentioned There is an advantage that it is possible to effectively suppress a decrease in strength of the portion due to enlargement of the diameter of the foam cell in accordance with the short shot. Therefore, there is an advantage that it is possible to effectively prevent a local strength decrease in the foamed resin molded product 7 due to the enlargement of the foamed cell diameter with a simple configuration.

  Instead of the above-described embodiment configured to actively cool the weld portion 13 in the cavity 1 by supplying cold water to the water passage 19, as shown in FIG. By installing a cover plate 39 made of a copper plate material or the like having a high thermal conductivity on the cavity surface 1a of the mold 2 located in the cavity 1, the weld portion 13 where a plurality of melt-foamable resin flows merge in the cavity 1 is provided. You may comprise a production | generation part etc. so that it may cool to low temperature rather than another site | part at least during the said formation process.

  According to the above-described configuration, when the high-temperature melt-foamable resin 3 reaches the installation portion of the cover plate 39, the heat of the melt-foamable resin 3 is taken away according to the heat radiation effect exhibited by the cover plate 39. Therefore, as a result, the generation part of the weld portion 13 is cooled to a lower temperature than other portions at least during the molding step. Therefore, it is possible to prevent the foamed resin molded product 7 from being locally reduced in strength due to the formation of the enlarged foam cell 7b in the weld portion 13 with a simpler configuration.

  FIG. 8A shows a foamed resin molding in which a melt-foamable resin 3 is supplied into the cavity 1 in a state where a reinforcing material 40 made of a nonwoven fabric or the like is preliminarily installed in the generation portion of the weld portion 13 in the cavity 1. A reference example of a molding method for forming the product 7 is shown. According to this reference example, when the molten foamable resin 3 was supplied into the cavity 1 to form the foamed resin molded article 7, the melted foamable resin 3 was supplied to the weld portion 13 as shown in FIG. By impregnating the reinforcing material 40 with the melt-foamable resin 3 and entangle the reinforcing material 40 with the melt-foamable resin 3, the weld portion 13 can be effectively reinforced, so that the portion is enlarged. It is possible to prevent the local decrease in strength due to the formation of the foamed foam cell 7b from occurring in the foamed resin molded product 7.

  In the foamed resin molded product 7 provided with the through holes 10 and 11 (see FIG. 2), the nonwoven fabric is formed on the peripheral surface of the insert pin disposed in the cavity 1 to form the through holes 10 and 11. In a state where a reinforcing material 40 made of, for example, is installed in advance, the molten foamable resin 3 is supplied into the cavity 1, so that the molten foamable resin 3 is impregnated into the reinforcing material 40 and melted with the reinforcing material 40. It is also possible to entangle the foamable resin 3 together. Then, when the insert pin is pulled out after the foamed resin molded product 7 is molded, the reinforcing material 40 may be peeled off from the insert pin and remain in the foamed resin molded product 7.

DESCRIPTION OF SYMBOLS 1 Cavity 1a Cavity surface 2 Molding die 3 Molten foamable resin 4 Supply means 6 Control means 7 Foamed resin molded product 13 Weld part 29 Cooling means

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 Forming the foamed resin by foaming and curing the foamed resin molded product, and forming a weld part where a plurality of melt-foamable resin flows merge in the cavity, at least during the molding process And a cooling step of cooling to a lower temperature.   2. The method for molding a foamed resin molded article according to claim 1, wherein the cooling step is configured so that the cavity surface located in the generation portion of the weld portion is cooled to a temperature lower than that of other portions.   The method for molding a foamed resin molded article according to claim 2, wherein cooling of the cavity surface located in the generation part of the weld part is started after the supply step of the melt-foamable resin is completed.   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. A foamed resin molded product comprising a cooling means for cooling a generation part of a weld part where a functional resin flow merges at a temperature lower than other parts during foaming and curing of the melt-foamable resin. Molding equipment.   7. The molding apparatus for a foamed resin molded product according to claim 6, wherein the cooling means cools the cavity surface located at the generating portion of the weld portion at a lower temperature than other portions.   8. The molding of a foamed resin molded article according to claim 7, further comprising control means for controlling the cooling of the cavity surface by the cooling means to start after the supply of the molten foamable resin to the cavity is completed. apparatus.   The melt foamable resin is substantially filled in the cavity of the mold by the supplying means, and then the mold is core-backed to foam the melt foamable resin. An apparatus for molding a foamed resin molded article according to claim 1.

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