Molding die, and method of manufacturing foamed molded article

Abstract

To provide a molding die that avoids unnecessary flow of a foaming raw material into an insert material which is integral-molded with a foamed molded article, to contribute to manufacturing of a sound foamed molded article.SOLUTION: A protrusion and a vertical wall that extends along a protruding direction of the protrusion beyond a top of the protrusion are formed on a bottom surface of a die, that partitions a cavity of a molding die.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a molding die used to manufacture a foam-molded product, particularly a foam-molded product into which an insert material is integrally molded, and a method for manufacturing a foam-molded product using the molding die. [Background technology]

[0002] In the case of vehicle seats such as automobiles, and seats for household use such as floor chairs and sofas, foam molded products (urethane foam) are sometimes integrally molded with insert materials during foam molding. Examples of such insert materials include backing materials for foam molded products and fasteners for the skin material that covers the surface of foam molded products.

[0003] For example, Patent Document 1 discloses a foam molding die used when integrally molding a backing material such as a nonwoven fabric as an insert material into a seat pad for a seat. As described in Patent Document 1, in order to integrally mold the backing material at a predetermined position of the foam molded product, the backing material is attached to the molding die using magnetic force.

[0004] Furthermore, the fasteners for the skin material described above are used to secure the skin material covering the foam molded product to the foam molded product, and a typical example is a hook-and-loop fastener. The hook-and-loop fastener must be firmly and stably embedded in the foam molded product when the foam molded product is foam molded. Therefore, even when the hook-and-loop fastener is placed inside the foam molding mold, it is often attached to the molding mold using magnetic force. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-233719 Summary of the Invention [Problem to be solved by the invention]

[0006] An example of a molding die to which the above-mentioned hook-and-loop fasteners can be attached is shown in FIG. 1. That is, as shown in FIG. 1, a cross section of a lower mold 1 of a foam molding die consisting of an upper mold and a lower mold is schematically shown. A convex portion 3 is formed on a mold bottom surface 2 that defines a cavity 10 of the molding die, and the foam molding is performed with a hook-and-loop fastener 4 attached to the top 30 of this convex portion 3. As shown in FIG. 2, a top view of region II in FIG. 1, the convex portion 3 is a ridge extending along the mold bottom surface 2 in a length and shape corresponding to the long hook-and-loop fastener 4 to be attached, and magnets 31 are embedded continuously or intermittently in the longitudinal direction inside. Meanwhile, as shown in FIG. 2, a magnetic body 40 is attached to the hook-and-loop fastener 4, so that the hook-and-loop fastener 4 is attracted to and fixed to the top 30 of the convex portion 3 via magnetic force.

[0007] As shown in Fig. 3, foam molding is performed by supplying foaming raw material 6 from a supply head 5 into the cavity 10 of the open lower mold 1, and then closing the upper mold (not shown) to foam the foaming raw material 6. Typically, the foaming raw material 6 is supplied to a plurality of predetermined positions in the cavity 10 by moving the supply head 5. Because the foaming raw material 6 is a low-viscosity liquid, it may cause strong flow at the mold bottom surface 2 depending on the amount and speed of supply.

[0008] In particular, the foaming raw material 6 supplied to the inclined portion 20 of the mold bottom surface 2 flows down the slope, and as a result, its flow speed becomes faster than, for example, the flat portion in the center. This causes the foaming raw material 6 to collide strongly with the convex portions 3 and the hook-and-loop fasteners 4. As shown by the arrows in Figure 4, this impinging flow of foaming raw material 6 lifts the hook-and-loop fasteners 4 attached to the convex portions 3 from their top portions 30, causing the hook-and-loop fasteners 4 to partially roll up. As a result, the foaming raw material 6 seeps into the gaps in the rolled-up portions of the hook-and-loop fasteners 4, and after foam molding, the surface of the hook-and-loop fasteners 4 on the top portion 30 side is covered with urethane foam. Because the surface of the hook-and-loop fasteners 4 on the top portion 30 side is the fastening surface of the hook-and-loop fastener, the urethane foam inhibits its fastening function, resulting in a defective product. This wastes material and is undesirable from an environmental standpoint.

[0009] Therefore, an object of the present invention is to provide a molding die that solves the above-mentioned problems when supplying foaming raw material, thereby preventing the foaming raw material from unnecessarily flowing into the insert material that is molded integrally with the foam-molded product, and thereby contributing to the production of sound foam-molded products. Another object of the present invention is to propose an advantageous method for producing a foam-molded product with an insert material. [Means for solving the problem]

[0010] The present inventors have conducted extensive research into ways to solve the above problems, and have found that an effective solution is to prevent the leading edge of the foaming raw material from colliding with the boundary between the convex portion on the bottom surface of the mold and the insert material on the convex portion when the foaming raw material is supplied into the mold cavity.

[0011] 1. A molding die having a convex portion on the bottom surface of the die that defines a cavity of the molding die, and a vertical wall that extends beyond the top of the convex portion along the protruding direction of the convex portion.

[0012] 2. A molding die used to manufacture foam molded products with insert materials, A molding die having a convex portion having an apex that serves as an attachment portion for the insert material, and a vertical wall that extends beyond the apex in the protruding direction of the convex portion by at least the thickness of the insert material, on the bottom surface of the die that defines the cavity of the molding die.

[0013] 3. The molding die according to 1 or 2 above, wherein the vertical wall extends from a position adjacent to at least a part of the side surface forming the convex portion along the protruding direction of the convex portion.

[0014] 4. The molding die according to any one of 1 to 3, wherein the vertical wall extends from the top of the convex portion along the protruding direction of the convex portion.

[0015] 5. The molding die according to any one of 1 to 4 above, wherein the vertical wall is provided on a convex portion arranged on an inclined portion of the bottom surface of the die.

[0016] 6. The molding die according to any one of 1 to 5 above, wherein the convex portion is a convex streak extending along the bottom surface of the die.

[0017] 7. The molding die according to 6, wherein the vertical wall extends continuously or intermittently in the longitudinal direction of the protrusion.

[0018] 8. A molding die described in any one of 1 to 7, wherein the vertical wall is adjacent to the side surface forming the convex portion that is oriented in a direction that crosses the flow direction of the foaming raw material injected into the cavity.

[0019] 9. The molding die according to any one of 1 to 8, wherein the insert material is a hook-and-loop fastener.

[0020] 10. A method for manufacturing a foam-molded product in which an insert material is integrally molded, After the insert material is attached to the top of a convex portion provided on the mold bottom surface that defines the cavity of the molding mold, when the raw material for the foam-molded product is supplied into the cavity, a vertical wall extending beyond the top of the convex portion along the protruding direction of the convex portion prevents the foam raw material from colliding with the top and the insert material at least at the inclined portion of the mold bottom surface, thereby performing foam molding. A method for manufacturing foam molded products. [Effects of the Invention]

[0021] According to the molding die of the present invention, when the foaming raw material is supplied into the mold cavity, the vertical wall prevents the leading edge of the raw material flow from colliding with, for example, the insert material, thereby preventing the foaming raw material from unnecessarily flowing into the insert material and enabling the production of sound foam-molded products. Furthermore, according to the manufacturing method of the present invention, adhesion of unnecessary urethane foam to the insert material can be avoided, thereby realizing manufacturing with a low defect rate. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a cross-sectional view of a lower mold of a molding die. [Figure 2] FIG. 2 is a top view showing region II of FIG. [Figure 3] FIG. 10 is an explanatory diagram showing a method for supplying a foaming raw material to the bottom surface of the lower mold. [Figure 4] FIG. 2 is an explanatory diagram showing the collision of a foaming raw material flow with a convex portion on the bottom surface of a mold. [Figure 5] FIG. 10 is a partial cross-sectional view of a lower mold showing a vertical wall provided on a convex portion of the mold bottom surface. [Figure 6] FIG. 6 is a top view of the protrusion shown in FIG. 5. [Figure 7] FIG. 10 is a partial cross-sectional view of a lower mold showing a vertical wall provided on a convex portion of the mold bottom surface. [Figure 8] FIG. 10 is a partial cross-sectional view of a lower mold showing another form of a vertical wall provided on a convex portion on the bottom surface of the mold. [Figure 9] 1 is a photograph of the locking functional surface side of a hook-and-loop fastener in a foam-molded product. DETAILED DESCRIPTION OF THE INVENTION

[0023] [Molding mold] An embodiment of the molding die of the present invention will be described in detail below with reference to Figures 5 and 6. Figures 5 and 6 show a portion corresponding to region II of the molding die 1 shown in Figure 1, and the same components as those in the molding die 1 shown in Figure 1 are given the same reference numerals and will not be described again. The insert material will be described using a hook-and-loop fastener as a typical example.

[0024] The molding die 1 shown in FIG. 5 has a vertical wall 7 that extends from a position adjacent to at least a part of the side surface forming the protrusion 3 along the protruding direction of the protrusion 3 beyond the top 30 of the protrusion 3 . In the illustrated example, the protrusions 3 are, as shown in the top view of Fig. 6, long, rectangular parallelepiped-shaped protrusions that are curved partway along, and have a vertical wall 7 on at least the side surface 3a that faces the supply section (see Fig. 3) of the foaming raw material 6 among the side surfaces that form the protrusions 3. In other words, the vertical wall 7 is provided along the protruding direction of the protrusions 3 in contact with the side surface 3a that the flow of the foaming raw material 6 first reaches among the side surfaces that form the protrusions 3.

[0025] Here, "along the protruding direction of the convex portion 3" means that it is sufficient to be roughly oriented in the protruding direction, and does not necessarily mean that it is on the contour line of the side surface 3a. The key is that it is sufficient to be oriented in a direction that prevents the foaming raw material 6 from colliding with the hook-and-loop fastener 4. Therefore, it may be oriented in a direction that is inclined with respect to the contour line of the side surface 3a, for example, vertical. From the viewpoint of the manufacturing efficiency of foam-molded products, it is preferable that it be in the direction in which the foam-molded product is pulled out. Therefore, the vertical wall 7 does not necessarily need to be in contact with the side surface 3a, and there may be a gap between the vertical wall 7 and the side surface 3a depending on the direction in which the vertical wall 7 extends, etc.

[0026] If there are other side surfaces forming the protrusions 3 on which the flow of the foaming raw material 6 collides, the vertical walls 7 may be provided in the same manner. For example, in the illustrated example, if the flow of the foaming raw material 6 collides with the side surfaces located at both ends in the longitudinal direction of the protrusions 3, the vertical walls 7 may of course be provided on these side surfaces.

[0027] Here, it is essential that the vertical wall 7 extends beyond the top 30 of the projection 3, specifically, that it extends beyond the top 30 by at least the thickness of the hook-and-loop fastener 4. In other words, at least the boundary between the top 30 of the projection 3 and the hook-and-loop fastener 4 must be covered by the vertical wall 7. This reliably prevents the hook-and-loop fastener 4 from peeling off from the top 30 due to the impinging flow of the foaming raw material 6. More specifically, the vertical distance t (see FIG. 5 ) from the top 30 of the projection 3 to the tip of the vertical wall 7 is preferably equal to or greater than the thickness of the hook-and-loop fastener 4, and more preferably greater than the thickness of the hook-and-loop fastener 4.

[0028] 6, the vertical wall 7 is provided continuously over the entire length of the projection 3 in the longitudinal direction, but may be provided discontinuously with a small gap therebetween. Alternatively, depending on the shape of the projection 3, the vertical wall 7 may be provided only on the side surface where the foaming raw material 6 first reaches.

[0029] In the molding die shown in Figure 5, a vertical wall 7 is provided on the convex portion 3 of the inclined portion of the mold bottom surface 2, where the flow of the foaming raw material 6 is likely to be fast. Note that Figure 5 is a partial enlarged view of region II, and as shown in Figure 3, there is also an inclined portion on the side of the mold bottom surface 2 of the molding die 1 opposite to region II across the central compartment. The foaming raw material 6 is also supplied to this inclined portion. Therefore, for the convex portion 3 of this inclined portion, a vertical wall 7 must also be provided on the side 3b on the central compartment side, as shown in Figure 7.

[0030] Incidentally, when the inclination angle of the inclined portion of the mold bottom surface 2 relative to the horizontal plane is 10° or more, the flow of the foaming raw material 6 becomes strong and the curling of the hook-and-loop fastener 4 becomes noticeable, so it is particularly advantageous to provide a vertical wall 7 on the convex portion 3 of such an inclined portion.

[0031] 3, when the central section in the mold bottom surface 2 where the foaming raw material 6 is supplied is flat, the flow of the foaming raw material 6 is gentle, so it is not necessarily necessary to provide the vertical wall 7 on the protrusion 3 arranged in the central section. However, when there is a concern that partial detachment of the hook-and-loop fastener 4 may occur due to the collision of the foaming raw material 6, for example, when the supply speed of the foaming raw material 6 in the central section is extremely fast, it is preferable to also provide the vertical wall 7 on the side of the protrusion 3 arranged in the central section where the foaming raw material 6 collides.

[0032] In addition, in the example shown in Figure 5, the vertical wall 7 extends in the protruding direction from the side surface 3a of the convex portion 3, but it may also be configured as shown in Figure 8, for example, in which the vertical wall 7 is placed on the surface of the top portion 30 of the convex portion 3, and the vertical wall 7 extends in the protruding direction from the surface of the top portion 30.

[0033] [Method of manufacturing foam molded products] Foam molding can be performed using the above-described molding die 1. That is, after a hook-and-loop fastener 4 is attached to the top 30 of a protrusion 3 provided on the bottom surface 2 of the die, foam molding is performed by supplying the foaming raw material 6 of the foam-molded product toward the bottom surface 2 of the die. As described above, when the foaming raw material 6 is supplied into the die, the vertical wall 7 arranged adjacent to a predetermined side surface of the protrusion 3 prevents the foaming raw material 6 from coming into contact with the top 30 and the hook-and-loop fastener 4, thereby preventing the urethane foam from seeping out onto the engaging surface side of the hook-and-loop fastener 4. [Example]

[0034] Using the molding die 1 shown in Figures 5 and 6, a 2 mm thick hook-and-loop fastener 4 was attached to the top 30 of the protrusion 3 via magnetic force, and then the foaming raw material 6 was supplied to the bottom surface 2 of the die as shown in Figure 2.Then, the upper die was closed and foam molding was carried out under a predetermined pressure to produce an automobile seat material.

[0035] A vertical wall 7 was provided on the side surface 3a of the protrusion 3 formed on the inclined portion 20 (inclination angle relative to the horizontal plane: 10°) of the mold bottom surface 2. The vertical wall 7 had a height of 2 mm extending from the top 30 of the protrusion 3, and was installed over the entire longitudinal length of the side surface 3a of the protrusion 3, as shown in FIG.

[0036] For comparison, foam molding was carried out under the same conditions using a molding die having the same configuration except that the vertical wall 7 was not provided.

[0037] In the seat material thus produced, the finished state of the hook-and-loop fastener 4 attached to the convex portion 3 of the inclined portion 20 of the mold bottom surface 2 was visually confirmed. Figure 9 shows a photograph of the locking surface of the hook-and-loop fastener 4 exposed on the surface of the seat material after molding. As shown in Figure 9, when there was no vertical wall, there was urethane foam attached (indistinct areas) to the locking element (hook portion) on the locking surface of the hook-and-loop fastener 4. In contrast, when there was a vertical wall, there was no urethane foam attached to the locking surface of the hook-and-loop fastener 4, and the locking element (hook portion) on the locking surface could be clearly seen. [Explanation of symbols]

[0038] 1 Lower mold 2. Mold bottom 3 Convex part 3a side 3b side 4 hook-and-loop fasteners 5 feeding head 6. Foaming materials 7 Vertical wall 10 cavities 20 Slope 30 Top 31 Magnet 40 Magnetic material

Claims

1. A molding die having a bottom surface that defines a cavity of the molding die, the bottom surface having a convex portion and a vertical wall that extends beyond the top of the convex portion along the protruding direction of the convex portion.

2. A molding die for manufacturing a foam molded product with an insert material, A molding die having a convex portion having an apex that serves as an attachment portion for the insert material, and a vertical wall that extends beyond the apex in the protruding direction of the convex portion by at least the thickness of the insert material, on the bottom surface of the die that defines the cavity of the molding die.

3. The molding die according to claim 1 or 2, wherein the vertical wall extends from a position adjacent to at least a part of the side surface forming the protrusion along a protruding direction of the protrusion.

4. The molding die according to claim 1 or 2, wherein the vertical wall extends from the top of the convex portion along the protruding direction of the convex portion.

5. The molding die according to claim 1 or 2, wherein the vertical wall is provided on a convex portion disposed on an inclined portion of the bottom surface of the die.

6. The molding die according to claim 1 or 2, wherein the convex portion is a ridge extending along the bottom surface of the die.

7. The molding die according to claim 6 , wherein the vertical wall extends continuously or intermittently in the longitudinal direction of the ridge.

8. The molding die according to claim 1 or 2, wherein the vertical wall is adjacent to one of the side surfaces forming the protrusion, the side surface being in a direction crossing the flow direction of the foaming raw material injected into the cavity.

9. The molding die according to claim 1 or 2, wherein the insert material is a hook-and-loop fastener.

10. A method for manufacturing a foam-molded product in which an insert material is integrally molded, comprising: After the insert material is attached to the top of a convex portion provided on the mold bottom surface that defines the cavity of the molding mold, when the raw material for the foam-molded product is supplied into the cavity, a vertical wall extending beyond the top of the convex portion along the protruding direction of the convex portion prevents the foam raw material from colliding with the top and the insert material at least at the inclined portion of the mold bottom surface, thereby performing foam molding. A method for manufacturing foam molded products.

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