JP2910978B2 - Method for producing resin molded product and molding die thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a resin molded product and a molding die thereof, and more particularly, to a production method using a resin molding method called stamping molding and a molding die therefor.

[Prior art]

As a simple method for producing a resin molded product in which a skin material is adhered to the surface of a resin substrate, there is a production method called stamping molding. FIG. 3 shows a method of manufacturing a resin molded product by this stamping molding. First, a product molding section 33 formed on a part of the mold surface of the lower mold 31 is melted or semi-melted from an external injection molding machine 39. The resin material 35 in the state is supplied, and the skin material 34 is arranged above the lower mold. And
By closing the lower mold 31 and the upper mold 32, the skin material 34 is compressed together with the resin material 35, and the both are pressed. Due to the pressure bonding, the resin material 35 is shaped into the shape of the product molded portion to become the base material 36, and at the same time, is integrated with the skin material 34 to obtain a desired resin molded product.

[0003] The skin material 34 is larger than the product forming portion 33 on the lower mold surface, and the periphery is a gripping portion when the skin material is placed. Therefore, in the resin molded product manufactured by the stamping molding, the skin material 34 protrudes from the edge of the base material 36, and the protruding skin material is cut off thereafter.

[0004] In the above-mentioned manufacturing method, the skin material is often used without being shaped and formed, and the lower mold and the upper mold are not heated, or even if heated, the skin material is not used. It is often used after being heated to a temperature lower than the melt softening temperature. Therefore, the skin material is not shaped and fixed to the upper mold surface shape, that is, the product shape during the production of the resin molded product, but is simply fixed to the base material surface by the adhesiveness of the molten or semi-molten resin material. Then, the shape is forcibly maintained.

Therefore, the force for restoring the original shape of the resin molded product remains in the skin material, and the skin material 34 is formed by the foamed resin layer 37 and the resin sheet layer 38 as shown in FIG. In the case of a laminated material or a foamed resin layer alone (not shown), the foamed layer 37 of the skin material swells and the product terminal, that is, the skin material 34 at the edge of the base material 36.
However, there was a problem that the outer shape was opened to impair the appearance. The opening of the skin material of the product end tended to appear largely when the edge did not have a flange-like bent portion as in the base material shown in FIG.

Conventionally, in order to prevent the skin material from opening at the product terminal, it has been conventionally proposed to provide a slide mold on the lower mold, and form the protruding skin material by folding the protruding edge toward the base material side by the slide mold. Have been. However, providing a slide mold complicates the mold structure,
Improvements have been demanded because the cost of mold production is high.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and provides a method for easily and inexpensively producing a resin molded product in which a skin material does not open outward at a product terminal after demolding, and It is intended to provide such a mold.

[0008]

According to the present invention, there is provided a skin material including a resin material in a molten or semi-molten state supplied to a product molding portion of a lower mold surface, and a foamed resin layer disposed above the lower mold. And crimped by clamping the lower mold and the upper mold,
A method for manufacturing a resin molded product in which the resin material is formed into a base material having a predetermined shape, and the skin material is laminated and integrated on the surface of the base material in a state where the skin material protrudes from the edge of the base material. A concave groove is formed on the outer periphery of the product forming portion of the lower mold surface where the protruding skin material comes into contact, and the skin material protruding from the edge of the base material at the time of the mold clamping is moved to the lower mold and the upper mold. The present invention relates to a method for producing a resin molded product, wherein the resin is compressed with a mold surface of a mold and is inserted into a concave groove of the lower mold surface.

Further, the present invention provides a lower mold having a mold surface partially formed with a product molding part to which a molten or semi-molten resin material is supplied, and a skin material disposed above the lower mold. A molding die comprising an upper die having a die surface for compressing the resin material together with the lower die surface together with the resin material at the time of clamping and pressing the resin material against the lower die surface, wherein the lower die is used for product molding. The present invention relates to a molding die, characterized in that a concave groove into which a skin material enters at the time of the die clamping is formed on a die surface on an outer periphery of the part.

[0010]

The resin molded article manufactured by using the manufacturing method or the mold according to the present invention has a structure in which the skin material is cut off at the edge of the base material even when the skin material is cut off at the edge of the base material after demolding. It did not open and had a good appearance. This is presumed to be due to the following reasons. In other words, when the mold is closed, the skin material compressed by the lower mold surface and the upper mold surface has a portion of the portion protruding from the edge of the base material enters the concave groove of the lower mold surface, and in that state, The base material is molded from the resin material and integrated with the skin material. Therefore, the skin material of the portion that has entered the concave groove is in a state where the amount of compression is smaller than that of the skin material portion pressed against the base material, and the skin material near the edge of the base material close to the concave groove has the following characteristics. A force acts toward the concave groove, that is, toward the back side of the product. As a result, the skin material is prevented from opening toward the product surface at the edge of the base material after the mold release.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing an example of a molding die for carrying out the manufacturing method of the present invention, and FIG. 2 is an enlarged view of a main part thereof.

FIG. 1 shows an example of a molding die according to the present invention.
This molding die is composed of a lower mold 10 and an upper mold 20, and a resin material 15 and a skin material 25 are pressed by clamping the lower mold 10 and the upper mold 20, and the resin material 15 is formed into a base having a predetermined shape. Lumber 1
7, and for laminating the skin material 25 protruding from the edge of the base material 17.

The mold surface 11 of the lower mold 10 defines the shape of the back surface of the product, and a product molding portion 12 is formed on a part of the surface. The product forming section 12 is formed by making the mold surface 11 concave in a predetermined base material shape, and a resin material 15 in a molten or semi-molten state is supplied from an external injection molding machine (not shown) to the gate 1.
4 to be injected. Resin material 15
Is preferably an ABS resin or a polypropylene resin containing a filler.

The outer peripheral surface of the product forming section 12 is provided with a concave groove 16 into which a skin material 25 enters. The concave groove 16 is used to clamp the lower mold 10 and the upper mold 20 to form the resin material 1.
5 is to reduce the amount of compression of the skin material 25 at the portion corresponding to the concave groove 16 when the surface material 25 is press-bonded, and is lower than the product forming part 12 and
It is provided at a portion where the skin material 25 protruding from the edge of the base material comes into contact.

According to this structure, when the lower mold 10 and the upper mold 20 are clamped, the skin material 25 enters the concave groove 16. Therefore, the skin material 25 in the concave groove 16 is maintained in a state of being expanded without being compressed. Thereby, the skin material 25 near the concave groove 16 is provided with the concave groove 16.
A force directed toward the mold surface of the lower mold 10 in which is present acts to prevent the skin material from opening to the product surface side at the edge of the base material after the molded product is released from the mold.

It is preferable that the concave groove 16 is provided so as to be as close as possible to the edge of the product forming portion 12. Normally, the distance between the groove 16 and the end of the product forming section 12 is set to about 2 to 3 mm, and is set to about 2 mm in this example.

A skin material 25 including a foamed resin layer is disposed above the lower mold 10. In this embodiment, the skin material 25 is made of a synthetic resin layer 2 made of soft vinyl chloride or the like.
3 is formed by laminating or backing a foamed resin layer 24 such as polyurethane foam, and the foamed resin layer 24 is disposed with the lower mold 10 side. In this example,
On the skin material 25, a polypropylene foam having a thickness of about 2.0 mm is also laminated on a soft vinyl chloride sheet having a thickness of about 0.8 mm. The skin material 25 is formed slightly larger than the product forming part 12, and in particular, the product forming part 1 is formed.
That is, it is formed in a size protruding from the edge of the base material 17 and reaching the concave portion 16. Thereby, when the lower mold 10 and the upper mold 20 are clamped, the skin material 25 can be inserted into the recess 16. In addition, the skin material 25 may be previously shaped into the upper mold surface shape by vacuum molding, press molding, or the like.

The upper mold 20 has a mold surface 21 for pressing the resin material 15 in the product molding section 12 and the skin material 25, and the lower mold 10 and the upper mold 20 are used for clamping. The resin material 15 and the skin material 25 are compressed between these steps.

Next, referring to FIG. 1 and FIG. 2, an example of the production of a resin molded product using the mold will be described. First, the resin material 15 constituting the base material is supplied from the gate 14 to the product forming section 12 of the lower mold 10, and the skin material 25 is arranged above the lower mold 10. Then, the lower mold 10 and the upper mold 20 are clamped, and the resin material 1 filled in the product molding portion 12 is formed.
5 is formed on the base material 17 having a predetermined shape, and is pressed against the back surface of the skin material 25. At this time, since the skin material 25 is formed so as to protrude from the edge of the base material and reach the concave portion 16, the skin material 25 is formed in a state where the skin material 25 enters the concave portion 16 by mold clamping.

After the resin material 15 has hardened, the lower mold 10 and the upper mold 20 are opened to take out the resin molded product. The obtained molded product is trimmed from the protruding portion of the skin material at the edge of the base material to form a product. The obtained product has a good appearance without the skin material being opened almost outward from the edge of the substrate.

In the above-described embodiment, an example has been described in which a gate is provided in the lower mold and the resin is supplied from the gate to the product molding portion on the mold surface. However, the present invention is not limited to this. For example, assuming that the lower mold does not have the gate, from a resin supply nozzle provided so as to be able to move in the lateral direction on the lower mold, a resin material is supplied to a product molding portion of the lower mold surface. Is also good. Further, the skin material may be composed of only a foamed layer.

[0022]

As shown and described above, according to the method for manufacturing a resin molded product and the molding die of the present invention, since the concave groove is provided on the outer periphery of the product molding portion of the lower die, The skin material protruding from the edge of the recess enters the recess by mold clamping. In the concave groove, since the skin material is hardly compressed by the upper die and the lower die, a force toward the mold surface of the lower die having the concave groove, that is, the back side of the product acts on the skin material near the concave groove. As a result, the opening of the skin material at the edge of the base material can be prevented, and a product having a good appearance can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a molding die for implementing a manufacturing method of the present invention.

FIG. 2 is an enlarged view of a main part thereof.

FIG. 3 is a cross-sectional view illustrating an example of a general stamping molding die.

FIG. 4 is a sectional view showing a part of the obtained product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lower mold 11 Mold surface 12 Product molding part 15 Resin material 16 Concave groove 20 Upper mold 21 Mold surface 23 Foam resin layer 25 Skin material

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B29C 43/18-43/20 B29C 43/34-43/42 B29C 33/12-33/14 B29C 33 / 42,45 / 14

Claims (2)

(57) [Claims] 1. A molten or semi-molten resin material supplied to a product forming portion of a mold surface of a lower mold, and a skin material including a foamed resin layer disposed above the lower mold, and A resin molded product which is press-bonded by clamping with a mold to form the base material of the resin material into a predetermined shape, and to laminate and integrate the skin material on the surface of the base material so as to protrude from the edge of the base material. In the manufacturing method, a concave groove is formed on the outer periphery of a product forming portion of a lower mold surface with which a skin material protruding from the edge of the base material comes into contact, and protrudes from the edge of the base material at the time of the mold clamping. A method of manufacturing a resin molded product, comprising compressing the skin material with the mold surfaces of the lower mold and the upper mold, and causing the skin material to enter into a concave groove of the lower mold surface. 2. A lower mold having a mold surface partially formed with a product molding portion to which a resin material in a molten or semi-molten state is supplied, and a skin material disposed above the lower mold is clamped. A molding die comprising an upper die having a die surface for compressing the resin material together with the lower die surface and compressing the resin material with the lower die surface, wherein the lower die has an outer periphery of a product forming portion of the lower die. A molding die, wherein a concave groove into which a skin material enters at the time of the mold clamping is formed on a surface.