JPH01152018A - Manufacture of formed product - Google Patents

Abstract

PURPOSE:To manufacture a foamed product almost without generating loss of material by using a top force with a material injection inlet, flowing the foaming material down on a skin through the material injection inlet under the state of mold closing to a given position to a bottom force and then mold registering the top and bottom forces and foaming. CONSTITUTION:A core material 16 and a skin 14 are set under the state of mold opening to a molding surface of a top force 18 forming a through-hole 36 as a material injection inlet and a cavity surface 24 of a bottom force 20. Then, the top force 18 is pivoted around an axis 22 to a position forming a space 40 of given dimension between both parting surfaces 32 and 26 on the free end sides of the top force 18 and the bottom force 20, and under said state, a given foaming material 42 such as urethane or the like is flowed down through the through-hole 36 of the top force 18. Then, the top force 18 is mold registered to the bottom force 20, and the peripheral section of the skin 14 is clamped between parting surfaces 32 and 26. Under said state, a foaming material 42 is foamed and cured to form a foaming layer 12.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for manufacturing a foamed product, and more particularly, to a method for manufacturing a foamed product having a structure in which a skin is integrally bonded to one side of a foam layer. be.

(Prior Art and its Problems) Some foam products with a foam layer have a structure in which a skin is integrally bonded to one side of the foam layer. For example, foamed products such as pads such as safety pads, cushions, and glove doors that are vehicle interior parts are examples.

By the way, foamed products with such a structure are usually made by combining an upper mold and a lower mold with a skin set thereon, with the peripheral edge of the skin sandwiched between the parting surfaces of the upper mold and the lower mold. However, it is manufactured by foaming a foam material between the skin set in the upper mold and the lower mold to form a foam layer. The foam material is injected into the mold by flowing down onto the skin, and after the injection operation is completed, the upper and lower molds are closed from the mold opening position and mold matching operations are performed. Because of this, it takes a long time to complete the mold matching between the upper mold and the lower mold after the injection of the foam material is completed. By then, the foam material has foamed and hardened, causing problems such as cell roughness, underfilling, and uneven density in the foam layer.

Conventionally, a material injection hole that opens to the molding surface is formed in the upper mold of the mold, and when the upper mold and the lower mold are matched, foam is formed into the cavity through the material injection hole in the upper mold. It is also a practice to inject material and, after injecting the foam material, close the material injection hole in the upper mold with a plug member to foam the foam material. There is a problem in that the mold release agent drips into the cavity, causing problems such as cell roughness and voids in the foam layer, resulting in a lack of reliability.

Furthermore, in the past, a method was also adopted in which the foam material was forcibly injected into the space between the upper mold and the skin formed by fitting the upper mold and the lower mold through runners and gates formed in the mold. However, this method inevitably causes material loss at the runner and gate sections, requires cleaning the launch section and gate section after each foam molding cycle, and requires large-scale equipment. There were some problems, and it was difficult to say that it was necessarily good in terms of economy and productivity.

(Solution Means) Against this background, the present invention provides an economically advantageous method for producing a foamed product having the structure described above, even when a foamed material with a high reaction rate is used. This was developed to provide a method for manufacturing foamed products that can be stably manufactured with good quality.The feature is that the upper mold and the lower mold with the skin set are The molds are matched with the peripheral edge of the skin sandwiched between the parting surfaces of the upper mold and the lower mold, and the foam material is foamed between the upper mold and the skin set in the lower mold to form a foam layer. When manufacturing a foamed product in which a skin is integrally joined to one side of the foam layer by forming an upper mold, the upper mold is provided with a material injection hole opening on the parting surface thereof. With the supranuclear mold closed to a predetermined position with respect to the lower mold, the foamed material is allowed to flow down onto the skin through the material injection hole, and the part between the upper mold and the lower mold is After introducing the foamed material into the space between the supranuclear mold and the epidermis set in the supranuclear mold through the gap between the molding surfaces, the upper mold and the lower mold are matched to form the foamed material. The reason is that foaming is performed.

(Function/Effect) According to this method, the foam material is injected with the upper mold and the lower mold closed to a predetermined position, so the mold is injected after the foam material injection operation is completed. The time required to complete the matching can be extremely shortened, and even when a foamed material with a fast reaction rate is used, the mold matching operation can be sufficiently completed before the foamed material foams and hardens. Therefore, it is possible to effectively prevent defects such as cell roughness, underfilling, and uneven density of the foam layer caused by foaming and hardening of the foam material at a stage before mold matching.

In addition, in the method of the present invention, in the space between the upper mold and the epidermis,
Since the foam material is introduced through the gap between the parting surfaces of the upper mold and the lower mold, there is almost no material loss, and the foam material is introduced through the material injection hole formed in the upper mold. Since it is only necessary to let the foam flow down through the filter, there is no need to introduce large-scale equipment, and foamed products can be manufactured economically in terms of both material savings and capital investment.

Furthermore, according to the method of the present invention, when the foam material is injected, the foam material is allowed to flow down onto the epidermis, so any excess foam material in the flowing part adheres to the epidermis side and is not molded. There is almost no adhesion, so there is almost no need to clean the mold, which can improve the foam molding cycle, and there is no need to close the material injection hole with a plug member when foaming the foam material. Therefore, the mold release agent applied to the plug member does not fall into the cavity, and therefore, no cell roughness occurs in the foam layer due to the contamination of the mold release agent. It is also possible to avoid the occurrence of cracks, voids, etc.

As described above, according to the method of the present invention, the disadvantages of the conventional method can be advantageously solved, and a foamed product with a skin of excellent quality can be produced economically and advantageously. Excellent effects can be obtained when using foam materials to improve the productivity of foam products with skins.

(Example) Hereinafter, in order to clarify the present invention more specifically,
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to the manufacture of a safety pad, which is a vehicle interior component, will be described in detail based on the drawings.

First, FIGS. 1 and 2 show a safety pad 10, which is a foamed product manufactured according to the method of this embodiment. As shown therein, the safety pad 10 manufactured according to the method of this embodiment has a decorative skin 14 on the product surface side of the foam layer 12 of a predetermined thickness.
Further, the product has a structure in which a core material 16 as a reinforcing material and a mounting material are each integrally joined to the back surface of the product.

On the other hand, FIG. 3 shows an example of a foaming mold suitable for use in manufacturing the safety pad 10. Here, reference numerals 18 and 20 denote an upper mold and a lower mold, respectively, which constitute a foam mold, and are connected so as to be rotatable around an axis 22. By being rotated around 22, these upper molds 1
8 and the lower mold 20 are opened and closed.

Here, the cavity surface 24 of the lower mold 20 is formed to have a shape corresponding to the surface of the safety pad 10 on the product surface side. A predetermined width portion of the inner circumferential portion of the parting surface 26 surrounding the cavity surface 24 is formed as an inclined surface 28 that slopes downward toward the inner circumferential side.

On the other hand, the molding surface of the upper mold 18 that defines the cavity surface is formed to have a shape corresponding to the surface of the product back side of the safety pad 10, and the parting surface 32 is
It is formed to have a structure having an inclined surface 34 corresponding to the inclined surface 28 of the parting surface 26 of the lower mold 2o. In the present embodiment, as shown in FIG. A through hole 36 serving as a material injection hole is formed to open in the inclined surface 34 and pass through the upper mold 18 in the thickness direction. As is clear from the figure, the through hole 36 is formed in a tapered shape with a larger diameter on the parting surface 32 side.

By the way, the safety pad 1o will be manufactured in the following manner using such a foaming mold.

That is, when manufacturing the safety pad 10, first, as shown in FIG. and the epidermis 14 is set.

Here, the core material 16 set in the upper mold 18 is formed in advance to have a shape corresponding to the surface shape of the product back side of the safety pad 10, and is usually made of a predetermined resin material by injection molding or the like. Those molded using an appropriate molding method will be used.

Further, as the outer skin 14, a resin material such as vinyl chloride resin is formed on the safety pad 10 by a vacuum forming method or the like.
The safety pad 10 is molded into a shape corresponding to the surface shape of the product surface side (
The skin 14 is larger than the cavity surface 24) of the lower mold 20, and when the lower mold 20 is set in the lower mold 20, the inclined surface 28 of the parting surface 26 of the lower mold 20 is
Almost the entire surface is covered by the periphery of No. 4. That is, as a result, the parting surface 2 of the lower mold 20 corresponding to the opening of the through hole 36 formed in the upper mold 18
6 is covered with the skin 14, and the peripheral edge of the skin 14 is held between the parting surfaces 32 and 26 of the upper mold 18 and the lower mold 20 during mold matching described later. This is how it is.

When the setting of the core material 16 and the skin 14 to the upper mold 18 and the lower mold 20 is completed, as shown in FIG. The upper mold 18 is rotated about the shaft 22 to a position where a gap 40 of a predetermined size is formed therebetween. As shown in the figure, in this state, a predetermined foam material 42 such as urethane is made to flow down through the through hole 36 of the upper mold 18.

In this way, the foam material 42 is flown down onto the peripheral edge of the skin 14 that covers the inclined surface 28 of the parting surface 26 of the lower mold 20, and the foam material 42 flowed down onto the skin 14 is It flows down on the skin 14 along the slope 28 and passes through the gap 40 between the upper mold 18 and the lower mold 20 to form a cavity forming space between the upper mold 18 and the lower mold 20, that is, between the core material 16 and the skin 14. It is introduced and injected into the space between.

When the injection operation by flowing down the foam material 42 into the through hole 36 is completed, the upper mold 18 is then quickly rotated around the shaft 22, as shown in FIG.
8 is mold-matched to the lower mold 20, and the peripheral edge of the skin 14 is aligned with the parting surface 32. of the upper mold 18 and the lower mold 20.
It is held between 26. Then, the foam material 42 is foamed and hardened in this mold-aligned state, and the foam layer 12 is formed. Then, such a foam layer 12
After forming, the upper mold 18 is rotated around the shaft 22 to open the mold, and the foamed molded product is taken out from the mold, and the skin 14 is removed.
The excess periphery of is removed.

As a result, as described above, the safety pad 10 is obtained as a foamed product in which the core material 16 is integrally joined to the back side of the foam layer 12 and the skin 14 is integrally joined to the front side of the product. It will be done.

According to the method of this embodiment, as described above, the upper mold 18
Since the injection operation of the foam material 42 is performed while the foam material 42 is brought close to the lower mold 20 by a predetermined distance, the foam material 4
After the injection operation in Step 2 is completed, the time required for the upper mold 18 to be mold-aligned with the lower mold 20 can be extremely shortened. Therefore, even when a highly reactive urethane or the like with a fast reaction rate is used as the foaming material 42, foaming is possible. The mold matching operation between the upper mold 18 and the lower mold 20 can be completed before the material 42 foams and hardens. Therefore, even if a foamed material 42 with a fast reaction rate is used, foaming and hardening of the foamed material 42 before mold matching can be effectively avoided, and the foaming material 42 can be prevented from foaming in the stage before mold matching. It is possible to effectively prevent defects such as cell roughness, lack of thickness, uneven density, etc. from occurring in the foam layer 12 due to foaming and hardening of the material 42.

Incidentally, in the method of this embodiment, when a highly reactive urethane with a cream time of 3 seconds is employed as the foam material 42, a foam layer 12 of good quality with significantly less cell roughness, underfilling, density unevenness, etc. is obtained. It is recognized that it can be obtained stably.

Note that, as is clear from the above description, the dimension of the gap 40 between the parting surfaces 32 and 26 of the upper mold 18 and the lower mold 20 is generally smaller as the reaction rate of the foam material 42 used is faster. However, any size can be set as long as the mold matching can be completed after the injection operation of the foam material 42 is completed and before the foam material 42 foams and hardens.

Further, according to the method of this embodiment, as described above, the core material 16
Since the foamed material 42 is introduced into the space between the upper mold 18 and the lower mold 20 through the gap 40 between the parting surfaces 32 and 26, there is almost no material loss. The foamed material 42 is not formed in the upper mold 2.
Since it is only necessary to let the water flow down through the through hole 36 formed at 0, there is no need to introduce large-scale equipment.
Compared to the method of forcibly injecting foam material through runners or gates formed in the foam mold, this method has economic advantages such as significant material savings and capital investment costs. It is.

Furthermore, according to the method of this embodiment, the through holes 36 of the upper die 18
The foamed material 42 flowed down through the through-hole 36 is guided over the skin 14 set on the lower mold 20 and introduced into the space between the core material 16 and the skin 14. The excess foam material 42 remaining inside the mold adheres to the skin 14 and hardly adheres to the upper mold 18, so that it is almost unnecessary to clean not only the lower mold 20 but also the upper mold 18. Accordingly, the foam molding cycle of the foam layer 12 can be shortened and the productivity of the safety pad 10 can be improved. Further, since the through hole 36 does not need to be closed with a plug member, the mold release agent applied to such a plug member does not fall into the cavity. This makes it possible to prevent cell roughness, voids, etc. from occurring in the foam layer 12 due to falling.

In this way, according to the method of this embodiment, the safety pad 1
0, even if a material with a fast reaction rate is used as the foam material 42, it is possible to stably and economically advantageously manufacture the safety pad 10 with excellent quality. This makes it possible to manufacture the safety pad 10 more advantageously than with conventional methods, especially when using a foamed material 42 that responds quickly to improve the productivity of the safety pad 10.

Although one embodiment of the present invention has been described in detail above, this is a literal illustration, and it goes without saying that the present invention should not be interpreted as being limited to this specific example.

For example, in the embodiment described above, only one through hole 36 as a material injection hole was formed in the upper mold 18, and the foam material 42 was allowed to flow down through the one through hole 36. A plurality of through holes 36 are formed in the mold 18, and the foam material 42 is passed through the plurality of through holes 36.
It is also possible to make it flow down.

Further, in the above embodiment, the upper mold 18 is connected to the lower mold 20 so as to be rotatable around the shaft 22, and the mold opening/closing operation is performed by the rotation of the upper mold 18 around the shaft 22. We have described an example using upper mold 18 or lower mold 2.
The present invention can also be applied to the case of using a foaming mold of the type in which the mold opening and closing operations are performed by a zero lifting operation.

Further, in the above embodiment, an example was described in which a safety pad, which is a vehicle interior part, is manufactured. However, the present invention is not necessarily limited to the manufacture of such a safety pad. Foam products that have a structure in which they are integrally joined can also be applied to the manufacture of other foam products such as pads and cushions other than safety pads, vehicle interior parts such as glove doors, and furniture. It is possible.

In addition, although it is omitted to list specific examples one by one, the present invention can be implemented with various changes, modifications, improvements, etc. without departing from the spirit thereof.
It goes without saying.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a safety pad, which is an example of a foamed product manufactured according to the method of the present invention, and FIG. 2 is a cross-sectional view taken along the line ■-■. FIG. 3 is a sectional view showing an example of a foam mold suitable for manufacturing the safety pad shown in FIG. 1, and FIGS. 4, 5, and 6 are
3A and 3B are explanatory diagrams for explaining a manufacturing process when manufacturing the safety pad shown in FIG. 1 using the foam molding mold shown in FIG. 3. FIG. 10: Safety pad (foam product) 12: Foam layer 14: Outer skin 16: Core material 18 2 Upper mold 20: Lower mold 26. 32: Parting surface 2B, 3
4: Inclined surface 36: Through hole (material injection hole)

Claims (1)

[Claims] An upper mold and a lower mold with a skin set thereon are matched with the peripheral edge of the skin sandwiched between the parting surfaces of the upper mold and the lower mold, and the upper mold and the lower mold are placed together. When producing a foamed product in which the skin is integrally joined to one side of the foam layer by foaming the foam material between the skin and the skin set in the lower mold to form a foam layer, As the upper mold, an upper mold equipped with a material injection hole opening on the parting surface is used, and with the upper mold closed to a predetermined position with respect to the lower mold, the foaming is carried out through the material injection hole. The material was allowed to flow down onto the skin, and the foam material was introduced into the space between the upper mold and the skin set in the lower mold through the gap between the parting surfaces of the upper mold and the lower mold. A method for manufacturing a foamed product, characterized in that the upper mold and the lower mold are then mold-matched to foam the foamed material.