Method for manufacturing a resin foam

Abstract

A mold (200) is a mold for forming a foam body, which includes a mold main body (260) and an exhaust member (270) attached to the mold main body, the exhaust member being composed of a porous metal, and a surface (270a) of the exhaust member on the side of a mold cavity of the mold constituting a part of a molding surface (S) of the mold.

Description

TECHNICAL FIELD

[0001] The present application relates to a mold, a vent member, and a method for manufacturing a resin foam.

[0002] This application claims priority from Japanese Patent Application No. 2020-197384 filed on November 27, 2020, the content of which is incorporated herein by reference in its entirety. BACKGROUND

[0003] In the past, there has been a mold for foam molding including a mold main body and a vent member (for example, Patent Literature 1).

[0004] Prior art documents

[0005] Patent documents

[0006] Patent Literature 1: Japanese Patent No. 6622571 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, in the mold of the past, maintenance of the vent member can be time-consuming and labor-intensive.

[0009] An object of the present application is to provide a mold, a vent member, and a method for manufacturing a resin foam, which can reduce labor and time for maintenance of the vent member.

[0010] SOLUTION TO PROBLEM

[0011] The mold of the present application is a mold for foam molding, which includes:

[0012] a mold main body; and

[0013] a vent member installed to the mold main body,

[0014] the vent member is composed of a porous metal,

[0015] a surface of the vent member on the side of a mold cavity of the mold constitutes a part of a molding surface of the mold.

[0016] The vent member of the present application is used for the above-described mold, in which:

[0017] the vent member is composed of a porous metal,

[0018] a surface of the vent member on the side of a mold cavity of the mold constitutes a part of a molding surface of the mold.

[0019] The method for manufacturing a resin foam of the present application uses the above-described mold, in which:

[0020] The resin foam manufacturing method includes a foaming step in which a foaming resin material is arranged at a predetermined arrangement site in a cavity of the mold, the mold is closed, and a resin foam is foamed and formed,

[0021] In the foaming step, gas in the cavity is discharged to the outside of the mold via the exhaust member.

[0022] Effects of the Invention

[0023] According to the present application, a mold, an exhaust member, and a resin foam manufacturing method that can reduce labor and time for maintenance of the exhaust member can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a sectional view of a mold of Embodiment 1 of the present application configured to form a backrest pad for a seat pad, using a cross section along an extension direction of the backrest pad.

[0025] Figure 2 is a sectional view of the mold of Figure 1 , using a cross section along a left-right direction.

[0026] Figure 3 is an enlarged view of a portion of the exhaust member of Figure 1 , enlarged.

[0027] Figure 4 is a view for explaining a mold releasing agent application step of a resin foam manufacturing method of an embodiment of the present application, and is a view showing a case where a mold releasing agent is applied to the exhaust member from the outside, with respect to the mold of Figure 1

[0028] Figure 5 is a view for explaining a mold releasing agent application step of a resin foam manufacturing method of an embodiment of the present application, and is a view showing a case where a mold releasing agent reaches a surface of the cavity side of the exhaust member, with respect to the mold of Figure 1

[0029] Figure 6 is a view for explaining a foaming step of a resin foam manufacturing method of an embodiment of the present application, and is a view showing a case where a foaming resin material is arranged at a predetermined arrangement site and the mold is just closed, with respect to the mold of Figure 1

[0030] Figure 7 is a view for explaining a foaming step of a resin foam manufacturing method of an embodiment of the present application, and is a view showing a case where a foaming resin material is filled into the cavity halfway, with respect to the mold of Figure 1

[0031] ​​​​Figure 8 is a view for explaining a foaming step of a method of manufacturing a resin foam body of an embodiment of the present application, and is a view showing a state where a foaming resin material is filled in a mold cavity of a mold of Figure 1 is a view showing a state where a foaming resin material is filled in a mold cavity of a mold of

[0032] Figure 9 is a sectional view showing a mold of the second embodiment of the present application configured to form a seat cushion for a seat cushion, and is a view showing a state just after the mold is closed after a foaming resin material is disposed at a predetermined disposition site.

[0033] Figure 10 is a sectional view showing a mold of Figure 9 is a view showing a state just after the mold is closed after a foaming resin material is disposed at a predetermined disposition site.

[0034] Figure 11 is a view showing a state where a foaming resin material is filled in a mold cavity of a mold of Figure 9

[0035] Figure 12 is a perspective view showing an example of a vehicle seat provided with a seat cushion.

[0036] Figure 13 is a perspective view showing a backrest cushion of Figure 12 from the back side. DETAILED DESCRIPTION

[0037] The mold, the exhaust member, and the method of manufacturing a resin foam body of the present application are preferably used for forming any resin foam body, more preferably for forming a resin foam body composed of a resin having flexibility, for example, preferably for forming a seat cushion (particularly, a vehicle seat cushion). Here, the "resin having flexibility" means a resin that can be deformed when an external force is applied, for example, preferably a resin of an elastic system, more preferably a polyurethane.

[0038] Hereinafter, embodiments of the mold, the exhaust member, and the method of manufacturing a resin foam body of the present application will be described with reference to the drawings.

[0039] Common components in the respective drawings are denoted by the same reference numerals.

[0040] Figures 1 to 8 A mold 200 and an exhaust member 270 of the first embodiment of the present application are shown. Figures 9 to 11 A mold 200 and an exhaust member 270 of the second embodiment of the present application are shown. Hereinafter, these embodiments will be described together for convenience of explanation.

[0041] ​In the various embodiments described in this specification, the mold 200 is a mold configured for forming foam (e.g., resin foam) for forming foam.

[0042] In the various embodiments described in this specification, the mold 200 includes a mold body portion 260 and one or more venting elements 270. More specifically, the mold 200 is composed of the mold body portion 260 and one or more venting elements 270. The mold body portion 260 is the part of the mold 200 other than the one or more venting elements 270.

[0043] The venting member 270 is mounted on the mold body portion 260. More specifically, the venting member 270 is inserted into a hole provided in the mold body portion 260. As a method of mounting the venting member 270 on the mold body portion 260, it is preferably fixed and / or pressed in by adhesive bonding.

[0044] The main body of the mold 260 is made of metal.

[0045] The exhaust component 270 is made of porous metal. That is, as shown... Figure 3 As shown in the magnified view, the venting member 270 has a plurality of unit holes 272 and a skeleton portion 271 dividing these unit holes 272. The unit holes 272 are voids. The skeleton portion 271 is made of metal. The venting member 270 has a communicating bubble structure in which the unit holes 272 are interconnected. The venting member 270 is configured to allow gas to pass through the unit holes 272, thereby enabling the gas in the mold cavity CV to be released to the outside of the mold 200.

[0046] The mold 200 has a forming surface S configured for molding a foam (e.g., a resin foam). The forming surface S divides the mold cavity CV.

[0047] The surface 270a of the venting member 270 on the side of the mold cavity CV forms part of the forming surface S of the mold 200, that is, it faces the mold cavity CV.

[0048] The mold 200 can be configured to form any resin foam, preferably to form a resin foam made of a flexible resin, such as preferably to form a resin foam made of polyurethane foam. Furthermore, the mold 200 can be configured to form a foam for any purpose, for example, it can also be configured to form a seat cushion. Figures 1 to 8 The mold 200 shown in the first embodiment is configured as a backrest cushion forming mold 220, which is configured for forming... Figure 12 The backrest cushion 20 of the seat cushion (i.e., vehicle seat cushion) 1 used in the vehicle seat 100 shown. Figures 9 to 11The mold 200 of the second embodiment shown is configured as a seat cushion forming mold 210, which is configured for forming... Figure 12 The seat cushion 10 of the seat cushion (i.e., vehicle seat cushion) 1 used in the vehicle seat 100 shown.

[0049] Here, refer to Figures 12 to 13 Instructions for seat cushion 1.

[0050] The seat cushion 1 includes a seat cushion 10 for a person to sit on and a backrest cushion 20 for supporting the back of the person to sit on. Figure 13 The image shows the backrest cushion 20 viewed from the rear (BS) side. The seat cushion 10 and backrest cushion 20 each constitute the seat cushion 1. Hereinafter, the seat cushion 10 or backrest cushion 20 will sometimes be simply referred to as "seat cushion 1". The vehicle seat 100, in addition to the seat cushion 1, includes, for example, a cover (not shown) covering the surface side (seat passenger side) of the seat cushion 1, a frame (not shown) supporting the seat cushion 10 from below, a frame (not shown) provided on the back side of the backrest cushion 20, and a headrest 40 provided on the upper side of the backrest cushion 20 for supporting the head of the seat passenger. The cover is, for example, made of a breathable material (cloth, etc.). Figure 1 In the example, the seat cushion 10 and the backrest cushion 20 are constructed independently of each other, but they can also be constructed as a single unit.

[0051] In addition, Figure 12 In the example, the headrest 40 is constructed independently of the backrest cushion 20, but the headrest 40 can also be constructed integrally with the backrest cushion 20.

[0052] like Figure 12 As shown, the seat cushion 10 includes: a main cushion portion (also called a "sitting portion") 11, configured to support the buttocks and thighs of the seated person from below; a pair of side cushion portions 12, located on the left and right sides of the main cushion portion 11, which are raised upwards compared to the main cushion portion 11 and configured to support the seated person from the left and right sides; and a backrest cushion opposing portion 13, located behind the main cushion portion 11 and configured to be arranged opposite to the backrest cushion 20 in the vertical direction. The main cushion portion 11 consists of a leg portion 11t configured to support the thighs of the seated person from below and a buttock portion 11h located behind the leg portion 11t and configured to support the buttocks of the seated person from below.

[0053] like Figure 12 and Figure 13As shown, the backrest cushion 20 includes: a main cushion portion 21 configured to support the back of a seated person from the rear; a pair of side cushion portions 22 located on the left and right sides of the main cushion portion 21, which protrude forward compared to the main cushion portion 21 and are configured to support the seated person from the left and right sides; an upper bridge portion 23a extending rearward from the upper end of the main cushion portion 21; an upper backrest portion 23b extending downward from the rear end of the upper bridge portion 23a; a pair of side bridge portions 24a extending rearward from the left and right outer ends of the pair of side cushion portions 22; and a pair of side backrest portions 24b extending inward from the rear ends of the pair of side bridge portions 24a. The upper backrest portion 23b is separated from the main cushion portion 21 rearward. The upper bridge portion 23a connects the main cushion portion 21 and the upper backrest portion 23b. The pair of side backrest portions 24b are separated from the pair of side cushion portions 22 rearward. The pair of side bridge portions 24a connect the pair of side cushion portions 22 and the pair of side backrest portions 24b. A frame (not shown) is embedded between the main pad 21 and the upper back 23b and between a pair of side pads 22 and a pair of side backs 24b.

[0054] In this manual, the directions “up,” “down,” “left,” “right,” “front,” and “back” as viewed from the perspective of a person sitting in the vehicle seat 100 are referred to as “up,” “down,” “left,” “right,” “front,” and “back,” respectively.

[0055] Furthermore, in this specification, the "extending direction (LD) of seat cushion 1" (hereinafter also simply referred to as "extending direction (LD)") is a direction perpendicular to the left-right direction and the thickness direction (TD) of seat cushion 1, such as... Figure 12 As shown, in the case of seat cushion 10, it refers to the front-to-back direction, and in the case of backrest cushion 20, it refers to the direction in which the main cushion portion 21 of backrest cushion 20 extends from its lower surface to its upper surface.

[0056] In addition, the "thickness direction (TD) of seat cushion 1" (hereinafter also referred to as "thickness direction (TD)") is as follows: Figure 12 As shown, in the case of seat cushion 10, it refers to the vertical direction, and in the case of backrest cushion 20, it refers to the direction in which the main cushion portion 21 of backrest cushion 20 extends from its side (surface) FS to the backrest BS.

[0057] Furthermore, the "side of the seatee (surface, FS)" of seat cushion 1 refers to the upper surface in the case of seat cushion 10, and the front surface in the case of backrest cushion 20. The "back side (BS)" of seat cushion 1 refers to the lower surface in the case of seat cushion 10, and the rear surface in the case of backrest cushion 20.

[0058] Next, refer to Figures 1 to 2 , Figure 8The structure of the mold 200 (i.e., the backrest cushion forming mold 220) according to the first embodiment of the present invention will be described in more detail. As described above, the mold 200 of the first embodiment is configured as a backrest cushion forming mold 220, which is configured for forming a backrest cushion 20 ( Figure 12 For convenience, in Figures 1 to 2 , Figure 8 In the image, an arrow indicates the resin foam 50 formed using mold 200. Figure 8 That is, the extension direction LD, the thickness direction TD, and the left and right directions of the backrest cushion 20. Figure 1 The mold 200 is represented by a cross section along the extension direction LD of the backrest cushion 20. Figure 2 The mold 200 is represented by a cross section along the left and right directions of the backrest cushion 20.

[0059] In the first embodiment, the mold 200 includes an upper mold 200U and a lower mold 200L disposed on the lower side opposite to the upper mold 200U. The upper mold 200U has an upper mold body portion 200UM and a mold core 200UI. Figure 8 As shown, the forming surface S of the upper mold 200U is configured to form the portion of the backrest cushion 20 that includes the back side BS. The forming surface S of the lower mold 200L is configured to form the portion of the backrest cushion 20 that includes the surface FS of the seated side. When the mold 200 is closed by combining the upper mold 200U and the lower mold 200L, a mold cavity CV is divided inside the mold 200.

[0060] In the first embodiment, the mold cavity CV includes: a mold cavity 21CV for forming the main pad portion ( Figures 1 to 2 , Figure 8 It is configured as a main molding pad 21; a pair of side pad molding cavities 22CV. Figure 2 Its configuration consists of forming a pair of side pads 22; and a mold cavity 23aCV for forming the upper bridge portion. Figure 1 , Figure 8 Its structure consists of a molded upper bridge portion 23a; and a mold cavity 23bCV for molding the upper back. Figure 1 , Figure 8 Its configuration includes a molded upper back 23b; and a pair of mold cavities 24aCV for forming the side bridges. Figure 2 The structure comprises forming a pair of side bridge portions 24a; and a pair of side back forming cavities 24bCV. Figure 2 ), which is formed into a pair of side backs 24b.

[0061] In the first embodiment, the venting member 270 forms part of the upper mold 200U. The mold body 260 forms the portion of the upper mold 200U other than this part and the lower mold 200L. More specifically, in the example shown in the figure, as... Figure 1As shown, the venting member 270 constitutes at least a portion of the upper mold 200U (specifically, the upper mold body 200UM) facing the upper back forming cavity 23bCV. However, the venting member 270 can constitute any part of the mold 200 (upper mold 200U and / or lower mold 200L). For example, although not shown in the figure, it is preferred to be any part other than the upper mold 200U and / or lower mold 200L. Figure 1 In addition to the venting member 270 shown, there is another pair of venting members 270 that constitute at least a portion of the upper mold 200U that faces a pair of side-back forming cavities 24bCV (particularly the lower end 24bb of the pair of side-back forming cavities 24bCV that forms the forming side-back 24b). Figure 13 (part of the part). In addition, the venting component 270 can also form part of the lower mold 200L.

[0062] Next, refer to Figures 9 to 11 The structure of the mold 200 according to the second embodiment of the present invention will be described. As described above, in the second embodiment, the mold 200 is configured as a seat cushion forming mold 210, which is configured to form a seat cushion 10 ( Figure 12 For convenience, in Figures 9 to 11 In the image, an arrow indicates the resin foam 50 formed using mold 200. Figure 11 That is, the extension direction LD, the thickness direction TD, and the left and right directions of the seat cushion 10. Figure 9 The mold 200 is represented by a cross section along the extension direction LD of the seat cushion 10. Figure 10 The mold 200 is represented by a cross section along the left and right directions of the seat cushion 10.

[0063] In the second embodiment, the mold 200 includes an upper mold 200U and a lower mold 200L disposed on the lower side opposite to the upper mold 200U. For example... Figure 11 As shown, the forming surface S of the upper mold 200U is a portion of the surface of the forming seat 10 that includes the back surface BS. The forming surface S of the lower mold 200L is a portion of the surface of the forming seat 10 that includes the surface FS of the seated side. When the mold 200 is closed by combining the upper mold 200U and the lower mold 200L, a mold cavity CV is divided inside the mold 200.

[0064] In the second embodiment, the mold cavity CV includes: a mold cavity 11CV for forming the main pad portion ( Figures 9 to 11 It is configured as a main molding pad 11; a pair of side molding cavities 12CV ( Figure 10 The structure comprises forming a pair of side pad portions 12; and a mold cavity 13CV for forming the opposite portion of the backrest pad. Figure 10 The backrest cushion is formed into a molded opposing portion 13. The main cushion forming cavity 11CV is composed of a leg lower portion forming cavity 11tCV, which is configured as a molded leg lower portion 11t.Figure 9 , Figure 11 ) and the lower buttocks forming mold cavity 11hCV (configured as a forming lower buttocks 11h) Figures 9 to 11 )constitute.

[0065] In the second embodiment, the venting member 270 forms part of the upper mold 200U. The mold body 260 forms the portion of the upper mold 200U other than this part and the lower mold 200L. More specifically, in the example shown in the figure, the venting member 270 forms at least a portion of the portion of the upper mold 200U facing the lower buttock forming cavity 11hCV. However, the venting member 270 can form any part of the mold 200. For example, the venting member 270 can also form part of the lower mold 200L.

[0066] Next, refer to Figures 4 to 8 This invention describes a method for manufacturing a resin foam according to one embodiment of the present invention. Figures 4 to 8 The example shown is a case where the mold 200 of the first embodiment of the present invention described above (and further, the mold 220 for forming a backrest cushion) is used, but the method for manufacturing the resin foam of this embodiment can be performed similarly using the mold 200 of any embodiment of the present invention.

[0067] The method for manufacturing resin foam in this embodiment includes a release agent application step and a foaming molding step.

[0068] First, in the mold release agent application step, mold release agent 60 is applied to the forming surface S of the mold 200. The mold release agent application step is performed before the foaming molding step.

[0069] It is preferable to apply the release agent 60 to the entire forming surface S of the mold 200, but it is also possible to apply the release agent 60 to only a portion of the forming surface S.

[0070] In the mold release agent application step, it is preferable to also apply the mold release agent 60 to the surface 270a on the mold cavity CV side of the venting member 270, which constitutes part of the forming surface S. In this case, it is also possible to... Figures 4 to 5 As shown, by allowing the release agent 60 to penetrate from the outside of the mold 200 into the vent 70 and reach the surface 270a of the vent 70 on the side of the cavity CV, the release agent 60 is applied to the surface 270a of the vent 270 on the side of the cavity CV. Thus, even in situations like... Figures 4 to 5 In cases where the surface 270a of the venting member 270 on the side of the mold cavity CV is in a position where it is difficult to apply the release agent 60 from the side of the mold cavity CV, the release agent 60 can be easily applied to the surface 270a of the venting member 270 on the side of the mold cavity CV. Figure 4 This illustrates the application of release agent to the venting component from the outside. Figure 5The illustration shows the situation where the release agent 60 reaches the surface 270a of the vent 270 on the side of the mold cavity CV. However, the release agent 60 can also be applied to the surface 270a of the vent 270 on the side of the mold cavity CV from the mold cavity CV side.

[0071] However, in the mold release agent application step, the mold release agent 60 may not be applied to the surface 270a of the venting member 270 on the side of the mold cavity CV.

[0072] Release agents include, for example, solvent-based release agents.

[0073] Next, in the foaming molding step, foaming resin material 50' is placed in a predetermined placement position 280 within the mold cavity CV of the mold 200, and the mold 200 is closed, thereby foaming and molding the resin foam body 50. Figures 6 to 8 The foamed resin material 50' is in a liquid state.

[0074] Figure 6 This shows the situation immediately after the foamed resin material 50' is placed at the predetermined configuration location 280 and the mold 200 is just closed. Figure 7 This shows the situation midway through filling the mold cavity CV with foamed resin material 50'. Figure 8 This shows the case when the mold cavity CV is filled with foamed resin material 50'.

[0075] The predetermined configuration part 280 is a part pre-determined for configuring the foamed resin material 50'. Figures 1 to 8 In the example, the predetermined configuration part 280 is the central part of the forming surface S of the lower mold 200L facing the main pad forming cavity 21CV in the left-right direction, and the part of the forming surface S of the lower mold 200L facing the pair of side pad forming cavities 22CV. Figure 2 , Figure 6 ).exist Figures 9 to 11 In the example, the predetermined configuration part 280 is the central part of the forming surface S of the lower mold 200L facing the main pad forming cavity 11CV in the left-right direction, and the part of the forming surface S of the lower mold 200L facing a pair of side pad forming cavities 12CV. Figure 9 , Figure 10 However, the predetermined configuration portion 280 can be located at any location within the mold cavity CV of the mold 200. Furthermore, the predetermined configuration portion 280 can exist at only one location or at multiple locations. It is preferred that the predetermined configuration portion 280 is located on at least a portion of the forming surface S of the lower mold 200L, making it easy to configure the foamed resin material 50'.

[0076] The foamed resin material 50' disposed at the predetermined placement location 280 gradually expands and fills the mold cavity CV, after which the resin foam 50 is formed into a shape corresponding to the mold cavity CV. Figure 7 , Figure 8 ).

[0077] During the foaming molding step, the gas inside the mold cavity CV (the gas present in the mold cavity CV and the gas generated by the reaction of the foaming resin material 50') is released to the outside of the mold 200 via the venting member 270. Figure 8 Therefore, it is possible to suppress excess air bubbles remaining in the resin foam 50, thereby suppressing defects such as insufficient filling in the resin foam 50.

[0078] After the foaming molding step, the resin foam 50 is removed by opening the mold 200, thereby obtaining the resin foam 50.

[0079] Alternatively, the mold release agent application step can be omitted.

[0080] In the embodiments described herein, as described above, the venting member 270 is made of porous metal, and the surface 270a of the venting member 270 on the side of the mold cavity CV forms part of the forming surface S of the mold 200. Thus, since the venting member 270 has a simple structure, compared to the case where the venting member has a complex structure like in Patent Document 1, the possibility of the foaming resin material 50' getting stuck in or entering the venting member 270 during foaming molding can be reduced. This reduces the labor and time required for maintaining the venting member 270, and further reduces the defect rate of the resin foam 50.

[0081] Furthermore, according to the embodiments described in this specification, the venting member 270 is made of porous metal, so the surface 270a of the venting member 270 on the side facing the mold cavity CV has the function of releasing gas from the mold cavity CV to the outside of the mold 200. Therefore, compared with the case where only a part of the venting member performs the function of releasing gas from the mold cavity CV to the outside of the mold 200, as in Patent Document 1, it is possible to more reliably suppress the residual excess air bubbles in the resin foam 50, thereby suppressing defects such as incomplete filling in the resin foam 50. In addition, in the venting member of Patent Document 1, only the outer periphery of the opening and closing portion facing the mold cavity performs the function of releasing gas from the mold cavity to the outside of the mold, while the portion directly below the opening and closing portion does not perform the function of releasing gas from the mold cavity to the outside of the mold, so it is possible for excess air bubbles to remain in the resin foam.

[0082] Furthermore, according to the various embodiments described in this specification, the venting member 270 is made of porous metal, and the surface 270a of the venting member 270 on the cavity CV side constitutes part of the forming surface S of the mold 200. Therefore, the surface 270a of the venting member 270 on the cavity CV side can be formed into any surface shape (e.g., a curved shape), which can more smoothly follow the desired surface shape (appearance shape) of the resin foam 50. In this respect, in Patent Document 1, the opening and closing portion of the venting member has a flat plate shape, which makes it difficult to follow the desired surface shape (appearance shape) of the resin foam, and may leave traces of the opening and closing portion in the resin foam.

[0083] Furthermore, according to the various embodiments described in this specification, the venting member 270 is made of metal. Therefore, compared to the case where the venting member 270 is made of resin or the like, it is possible to suppress, for example, the venting member 270 from being eroded by the release agent 60 made of a solvent-based material, resulting in blockage, softening, etc. In addition, since the venting member 270 is made of metal, the difference in the coefficients of thermal expansion between the mold body 260 and the venting member 270 can be reduced, thereby reducing the possibility of leakage of the foamed resin material 50' from the outside of the mold 200 due to the formation of a gap between the mold body 260 and the venting member 270 during foaming molding. Furthermore, since the venting member 270 is made of metal, it is easier to maintain a uniform temperature in the mold 200, thereby facilitating a uniform density distribution of the resin foam 50. Furthermore, since the venting member 270 is made of metal, the surface condition (surface layer, surface gloss, surface permeability, etc.) of the surface portion of the resin foam 50 formed using the surface 270a of the mold cavity CV side of the venting member 270 can be the same as the surface condition of the surface portion of the resin foam 50 formed using the forming surface S of the mold body 260.

[0084] The preferred structure and variations of the mold 200 will be described below. Regarding the structures described below, when the mold 200 has multiple venting elements 270, either only a portion (one or more) of the venting elements 270 may satisfy this structure, or all of the venting elements 270 may satisfy this structure.

[0085] In the various embodiments described in this specification, it is preferred that... Figure 1 , Figure 9 As in the examples, there is no height difference between the surface 270a of the vent 270 on the side of the mold cavity CV and the portion of the mold body 260 adjacent to the vent 270. As a result, it is possible to suppress the residue of the vent 270 on the resin foam 50.

[0086] In the embodiments described in this specification, the venting member 270 (specifically, the unit hole 272 of the venting member 270) is preferably configured to allow gas to pass through the mold cavity CV while preventing the foamed resin material 50' disposed within the mold cavity CV from passing through. This prevents the foamed resin material 50' from entering the unit hole 272 of the venting member 270 during foaming molding, thereby reducing the labor and time required for maintaining the venting member 270, and further reducing the defect rate of the resin foam 50.

[0087] In the various embodiments described in this specification, the venting member 270 can be made of any metal, preferably a metal whose main component is any one of iron, aluminum, and nickel. In this case, the difference in the coefficients of thermal expansion between the mold body 260 and the venting member 270 can be further reduced, thereby more effectively suppressing the formation of gaps between the mold body 260 and the venting member 270 during foaming molding.

[0088] In this case, the main body 260 of the mold is preferably made of a metal with aluminum or iron as the main component.

[0089] Metals whose main component is iron include iron, stainless steel, and maraging steel. Metals whose main component is aluminum include aluminum and aluminum alloys. Metals whose main component is nickel include nickel and nickel alloys.

[0090] In the embodiments described in this specification, the difference between the coefficient of linear expansion of the metal constituting the mold body 260 and the coefficient of linear expansion of the metal constituting the venting member 270 is preferably 15 × 10⁻⁶. -6 / K or less, preferably 12×10 -6 / K or below.

[0091] This allows for more effective suppression of gaps forming between the mold body 260 and the venting component 270 during foaming molding.

[0092] In addition, the coefficient of linear expansion of the aforementioned metals was measured in accordance with JIS Z 2285:2003.

[0093] In the various embodiments described in this specification, the exhaust component 270 is preferably like... Figure 1 , Figure 9 In each example, at least a portion extends integrally along the wall thickness direction of the mold 200. Therefore, the venting member 270 can effectively release the gas within the mold cavity CV to the outside of the mold 200.

[0094] However, the vent 270 may also be covered by the mold body 260 on the side opposite to the mold cavity CV. In this case, one or more vent holes extending through the portion of the mold body 260 covering the vent 270 can be provided. In this case, the gas in the mold cavity CV is released to the outside of the mold 200 through the vent holes after passing through the vent 270.

[0095] Alternatively, the mold body 260 may also have one or more vent holes that extend along the wall thickness direction of the mold 200 at a position separate from the vent 270.

[0096] In the various embodiments described in this specification, it is preferred that... Figures 1 to 11 As in other examples, the vent 270 is positioned separately from the predetermined placement portion 280 of the foamed resin material 50'. During foaming, the foamed resin material 50' gradually expands and fills the mold cavity CV, but as it moves away from the predetermined placement portion 280, filling takes time and many air bubbles are easily trapped. By positioning the vent 270 at a location separate from the predetermined placement portion 280 where such bubbles are easily formed, these excess air bubbles can be effectively removed. Therefore, excess air bubbles remaining in the resin foam 50 can be effectively suppressed.

[0097] In the various embodiments described in this specification, in the like Figures 1 to 11 In cases where the mold 200 includes an upper mold 200U and a lower mold 200L, as in various examples, the venting member 270 preferably forms part of the upper mold 200U. In this case, the predetermined placement portion 280 of the foaming resin material 50' is preferably at least a portion of the forming surface S of the lower mold 200L. In this case, during foaming molding, the foaming resin material 50' gradually expands upward from the forming surface S of the lower mold 200L while filling, but as it moves away from the predetermined placement portion 280 (and further, as it moves closer to the upper side), filling takes time and many air bubbles are easily entangled. By placing the venting member 270 at the upper side where such air bubbles are easily formed, these excess air bubbles can be effectively removed using the venting member 270. Therefore, it is possible to effectively suppress the retention of excess air bubbles in the resin foam 50.

[0098] In addition, in the like Figures 1 to 2 In the case where the upper mold 200U has an upper mold body 200UM and a mold core 200UI, the venting component 270 can form part of the upper mold body 200UM and / or the mold core 200UI.

[0099] However, as mentioned above, the venting component 270 can constitute any part of the mold 200. Furthermore, the mold 200 is not limited to a structure including an upper mold 200U and a lower mold 200L, and can have any structure.

[0100] In the various embodiments described in this specification, it is preferred that... Figures 1 to 8 As in the example, the vent 270 faces the foamed resin material 50' that is last reached within the mold cavity CV at the predetermined placement position 280 of the mold cavity CV. Figures 1 to 8 In the example, the mold cavity 23bCV is used for upper back molding. By arranging the vent 270 at the position furthest from the predetermined configuration part 280 where air bubbles are most likely to form, excess air bubbles can be effectively removed using the vent 270. Therefore, excess air bubbles remaining in the resin foam 50 can be effectively suppressed.

[0101] In the embodiments described in this specification, the exhaust component 270 is preferably manufactured using a 3D printer. Powder sintering is the preferred method for shaping the 3D printer, but other methods may also be used. Powder sintering is a method of sintering metal powder together by irradiating it with a laser.

[0102] By using a 3D printer to manufacture the exhaust component 270, the porous structure of the exhaust component 270 can be easily made to achieve the desired exhaust function.

[0103] In the various embodiments described in this specification, the porous structure formed by the exhaust member 270 can be arbitrary. For example, the exhaust member 270 can be like... Figure 3 The example is configured in a grid pattern. In this case, the unit holes 272 of the exhaust component 270 are arranged regularly, specifically, at equal intervals along two mutually orthogonal directions. Alternatively, the unit holes 272 of the exhaust component 270 may be arranged randomly.

[0104] The unit holes 272 of the exhaust component 270 are preferably of approximately uniform diameter. The unit holes 272 of the exhaust component 270 are preferably of approximately uniform shape.

[0105] In the various embodiments described in this specification, from the viewpoint of improving venting function, the area of ​​the surface 270a of the venting member 270 on the mold cavity CV side is preferably 9 cm². 2 The preferred size is 25cm. 2 That's all. Furthermore, the area of ​​the surface 270a of the venting member 270 on the mold cavity CV side is preferably 150 cm². 2 The preferred size is 110cm. 2 the following.

[0106] Industrial availability

[0107] The method for manufacturing the mold, venting component, and resin foam of the present invention is preferably used for molding any resin foam, more preferably for molding resin foam made of flexible resin, for example preferably for molding seat cushions (especially vehicle seat cushions).

[0108] Explanation of reference numerals in the attached figures

[0109] 200, Mold; 200L, Lower mold; LS, Lower mold forming surface; 200U, Upper mold; US, Upper mold forming surface; 200UM, Upper mold body; 200UI, Mold core; S, Forming surface; CV, Mold cavity; 210, Mold for seat cushion forming; 11CV, Mold cavity for main cushion forming; 11tCV, Mold cavity for lower leg forming; 11hCV, Mold cavity for lower buttock forming; 12CV, Mold cavity for side cushion forming; 13CV, Mold cavity for opposite backrest cushion forming; 220, Mold for backrest cushion forming; 21CV, Mold cavity for main cushion forming; 22CV, Mold cavity for side cushion forming; 23aCV, Mold cavity for upper bridge forming; 23bCV, Mold cavity for upper back forming; 24aCV, Mold cavity for side bridge forming; 24bCV, Mold cavity for side back forming. Mold cavity; 260, Mold body; 270, Venting component; 270a, Surface on the side of the mold cavity; 271, Skeleton; 272, Unit hole; 280, Pre-arranged position; 50, Resin foam; 50', Foaming resin material; 60: Release agent; 1, Seat cushion; 10, Seat pad; 11, Main cushion (sitting part); 11t, Lower leg part; 11h, Lower buttock part; 12, Side cushion part; 13, Opposite part of backrest cushion; 20, Backrest cushion; 21, Main cushion part; 22, Side cushion part; 23a, Upper bridge part; 23b, Upper back; 24a, Side bridge part; 24b, Side back; 24bb, Lower end; 40, Headrest; 100, Vehicle seat; TD, Thickness direction; LD, Extension direction; FS, Surface on the side of the seated person; BS, Back side.

Claims

1. A method for manufacturing a resin foam, wherein a mold is used in the method for manufacturing the resin foam. The mold is a mold used for forming foam. The mold includes: Mold body; as well as The venting component is installed on the main body of the mold. The exhaust component is made of porous metal. The surface of the venting component that faces the mold cavity side of the mold constitutes part of the forming surface of the mold. The method for manufacturing the resin foam includes a foaming molding step, in which foaming resin material is disposed at a predetermined location within the mold cavity of the mold, the mold is closed, and the resin foam is foamed and formed. In the foaming molding step, the gas inside the mold cavity is released to the outside of the mold via the venting device. The method for manufacturing the resin foam further includes a release agent application step, which applies a release agent to the forming surface of the mold, prior to the foaming step. In the mold release agent application step, the mold release agent is allowed to penetrate from the outside of the mold to the vent and reach the surface of the vent on the side of the mold cavity.

2. The method for manufacturing resin foam according to claim 1, wherein, The exhaust components are made of a metal whose main components are iron, aluminum, and nickel.

3. The method for manufacturing resin foam according to claim 1 or 2, wherein, The difference between the coefficient of linear expansion of the metal constituting the main body of the mold and the coefficient of linear expansion of the metal constituting the venting component is 15 × 10⁻⁶. -6 / K or below.

4. The method for manufacturing resin foam according to claim 1 or 2, wherein, The venting component extends integrally throughout the wall thickness direction of the mold.

5. The method for manufacturing a resin foam according to claim 1 or 2, wherein, The mold includes: Upper mold; and The lower mold is located on the lower side, opposite to the upper mold. The venting component forms part of the upper mold. The main body of the mold comprises the portion of the upper mold excluding the aforementioned part and the lower mold.

6. The method for manufacturing a resin foam according to claim 1 or 2, wherein, The venting component faces the final position of the foamed resin material within the mold cavity that is positioned at a predetermined location within the mold cavity.

7. The method for manufacturing a resin foam according to claim 1 or 2, wherein, The mold is configured to form a resin foam made of polyurethane foam.

8. The method for manufacturing a resin foam according to claim 1 or 2, wherein, The mold is configured to form a seat cushion.

9. The method for manufacturing a resin foam according to claim 1 or 2, wherein, The venting component is configured to allow gas to pass through the mold cavity while preventing the foamed resin material disposed within the mold cavity from passing through.

10. The method for manufacturing a resin foam according to claim 1 or 2, wherein, The exhaust components are manufactured using a 3D printer.

11. The method for manufacturing a resin foam according to claim 1 or 2, wherein, The exhaust components are configured in a grid shape.

12. The method for manufacturing a resin foam according to claim 1 or 2, wherein, The venting component faces the part of the mold cavity where the foamed resin material, which is positioned at the predetermined location during the foaming process, is last reached.

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