JP3081977B2 - Manufacturing method of multilayer molded products - 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 partially bonded multilayer molded product in which a skin material is bonded to a part of the surface of a thermoplastic resin molded product.

[0002]

2. Description of the Related Art Plastic molded articles are used in large quantities in all fields including automobiles and home appliances because of their economical efficiency, free shapeability, and light weight. However, on the other hand, there are drawbacks such as cheapness, cold feeling, and easy damage, and there is a strong demand for imparting decorativeness and softness. Conventionally, various methods have been proposed for producing a partially bonded multilayer molded product in which a skin material is bonded to only a part of the surface of a thermoplastic resin molded product, particularly for the purpose of imparting decorativeness.

In the case where a skin material and a molten resin are supplied between molds, the mold is clamped, and pressure molding is performed to manufacture a partially bonded multilayer molded product, the skin material is accurately adhered to a desired position of the molded product. It is important that they are combined with each other, and that the edges of the skin material are finished with good appearance. For this purpose, a molding method that devises a method of fixing the skin material has been proposed.

Heretofore, in order to obtain such a partially bonded multilayer molded product, there has been proposed a method in which the periphery of a skin material is held between a skin fixing plate and a lower mold (Japanese Patent Laid-Open No. 59-1507).
However, this method cannot be applied to a case where a skin material is to be bonded only to a part of a molded product, particularly to only a central portion.

Further, a method of setting a mold in a mold with a skin material interposed therebetween by using a special jig and molding it (Japanese Patent Laid-Open No. 2-17511)
No. 1) is difficult to apply when the shape of the end portion of the skin material is complicated and long.

As another method, there has been proposed a method of producing a partially bonded multilayer molded product having no displacement by providing a partition wall on a mold surface and placing a boundary portion of a skin material in accordance with the partition wall. JP-A-1-26414).

It is also conceivable to paste the skin material at a predetermined position by vacuum-suctioning the skin material from a gap between the peripheral edges of a part of the mold, and a method is also considered. Is monotonous and lacks luxury.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to solve these disadvantages of the conventional method. In a simple method, there is no positional displacement of the skin material, and the appearance of the edge of the skin material is luxurious. It is an object of the present invention to provide a method for producing a partially bonded multilayer molded article having a beautiful appearance.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above problems, and as a result, have used a mold having a specific structure.
The present inventors have found that a partially bonded multilayer molded article having an extremely good appearance can be obtained by vacuum suction of the skin material, and have completed the present invention. That is, in the present invention, a skin material and a thermoplastic resin in a molten state are supplied between an unclosed upper and lower molds, and a molded product is formed by cooling under pressure, and the skin material is attached to a part of the surface of the molded product. At the time of joining, a convex portion is provided in a lower mold portion where an end portion of the skin material is located, a concave portion is provided in a position corresponding to the convex portion of the upper mold, and vacuum suction is performed from a gap provided in the convex portion. This is a method for producing a multilayer molded product, wherein the peripheral edge of the skin material is fixed to a lower mold and molded.

As the thermoplastic resin used as the core material layer in the present invention, any of those usually used for compression molding, injection molding and extrusion molding can be used.
For example, polypropylene, polyethylene, polystyrene, acrylonitrile-styrene-butadiene block copolymer, thermoplastic resin such as nylon, non-foamable such as thermoplastic elastomer such as ethylene-propylene block copolymer, styrene-butadiene block copolymer Alternatively, a foamable resin can be used. In addition, those containing additives such as an inorganic filler, a filler pigment such as glass fiber, a lubricant, and an antistatic agent can be appropriately used.

The skin material used in the present invention includes woven fabric, nonwoven fabric, metal, fiber, thermoplastic resin net, paper,
Examples thereof include a sheet in which a metal foil is lined with a sheet so that it can be vacuum-adsorbed, and a sheet or film of a thermoplastic resin and a thermoplastic elastomer. Moreover, you may use what was decorated with the uneven | corrugated pattern, such as a grain, printing, dyeing, etc., or a foam. Further, these may be used alone or in the form of a laminated product obtained by laminating two or more of them using an adhesive or the like.

In the mold used in the molding method of the present invention, a convex portion is provided at a lower mold portion where an end of a skin material to be placed is located, and a concave portion is provided at a position corresponding to the convex portion of the upper mold. Is provided. Further, a gap is provided in the convex portion or at the base thereof for fixing the peripheral edge of the skin material to the lower mold by vacuum suction so as not to displace the skin material. In particular, when the gap is provided in the convex portion, the skin material vacuum suction trace of the molded product is inconspicuous because it is in the groove of the molded product, so the gap can be increased and the suction force can be increased, so the rigidity can be improved. Even in the case of a covered skin material, it can be easily fixed to a mold and can be molded efficiently.

[0013] The shape of the convex and concave portions is the shape of the molded product,
The thickness is appropriately determined in consideration of the thickness of the skin material and the design.
As for the shape of the projection, in order to finish the appearance of the skin material periphery beautifully, it is preferable that the base (a) be 1 to 10 mm and the height (b) be 2 to 15 mm.
The gap for vacuum suction provided in the convex portion is 0.05 to 1
mm is practically preferable, and is provided partially on the entire circumference of the convex portion or at an appropriate gap. In addition, the rising portion of the convex portion has a distance of 3 to the lower mold surface in order to improve the releasability of the molded product.
It is preferable to have a gradient of degrees or more.

In the molding method of the present invention, the skin material (9) is placed between the unclosed upper and lower molds so that the peripheral edge thereof matches the projection (3) provided on the lower mold (2). And gap (4)
Then, the outer periphery of the skin material is fixed to the lower mold (2) by vacuum suction. Next, a molten resin (8) is supplied between the skin material (9) and the upper mold (1), the mold is clamped, and the molded product is formed by pressurizing and cooling. The timing of supplying the resin (6) and closing the mold is important. The supply of the molten resin (8) is performed through a resin passage (7) provided in the upper mold. Usually, the mold clamping speed is set to 30 mm / sec or less, and the upper and lower mold clearances are (C + 5) to (C + 5).
+100) mm (where C represents clearance upon completion of shaping). Further, the mold is clamped until the clearance becomes Cmm, and then pressurized and cooled for a predetermined time to obtain a desired multi-layer molded product of the skin material.

[0015]

According to the method for producing a multilayer molded product of the present invention, in a molded product in which a skin material is bonded to a part of the surface of the molded product, the edge of the skin material is accurately set in the groove, and the periphery of the skin material is A product with a beautifully finished part can be efficiently manufactured. In addition, since the skin material bonding portion and the non-bonding portion are separated by the groove, a high-quality partially bonded synthetic product can be obtained. This multilayer molded product is particularly suitable as a vehicle interior product.

[0016]

Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the present invention.

EXAMPLE 1 A molding example in which a mold for molding the molded product shown in FIG. 2A is attached to a press machine having a clamping force of 300 tons and a molding apparatus shown in FIG. 1 is used will be described below.

As the skin material (9), a 0.7 mm-thick (manufactured by Kyowa Leather Co., Ltd.) liner made of a grained vinyl chloride sheet lined with a cloth, cut into 650 mm × 700 mm is used.

As the thermoplastic resin, polypropylene (Sumitomo Noblen BPZ5 manufactured by Sumitomo Chemical Co., Ltd.) is used.
077, 15% of talc added, and a melt flow index of 40 g / 10 minutes), and the heated product is supplied as a molten resin (8) to a mold and subjected to molding. The upper mold (1) and the lower mold (2) are at 80 ° C. and 60 ° C., respectively.
Set temperature to ° C.

The periphery of the skin material (9) supplied between the upper and lower molds (1, 2) is adjusted so that the periphery of the lower mold projection (3) matches the periphery of the lower mold projection (3). A suction is made through a vacuum hole (6) from a gap of 1 mm to be sucked on the lower mold (2) surface.

The lower mold (2) is raised at a speed of 200 mm / sec, and when the cavity clearance between the upper mold surface and the lower mold surface becomes 15 mm, the lower mold is stopped, and the thermoplastic resin is stopped. Was heated and melted at 230 ° C., and the molten resin (8) was supplied between the skin material (9) and the upper mold (1) through the resin passage (7) provided in the upper mold. When the lower mold (2) is further raised, the molten resin (8) flows, reaches the end of the cavity, is filled in the mold, clamped and shaped. Clearance between upper and lower molds at the time of final mold clamping is 2.0mm
It is. After pressurizing and cooling for 50 seconds, the target molded product is taken out. When the surface is free of wrinkles and tears, the appearance of the multi-layer molding is beautiful, with the outer periphery of the skin material set at a predetermined position in the groove of the molded product. Get the goods.

Example 2 A mold for molding the molded article shown in FIG. 4 is attached to a press machine having a mold clamping force of 300 tons, and a molding apparatus shown in FIG. 3 is used.

As a skin material, a grained 0.4 mm thick
A sheet obtained by laminating a 3.0 mm thick foamed polypropylene sheet (manufactured by Toray Industries, Inc., 15 times expansion ratio) with a vinyl chloride sheet (manufactured by Kyowa Leather Co., Ltd.) using an adhesive.

As the thermoplastic resin, polypropylene (Sumitomo Noblen BPZ5 manufactured by Sumitomo Chemical Co., Ltd.) is used.
077, 15% of talc added, and a melt flow index of 40 g / 10 minutes), and the heated product is supplied as a molten resin (8) to a mold and subjected to molding. The upper mold (1) and the lower mold (2) are at 50 ° C. and 40 ° C., respectively.
Set temperature to ° C.

The periphery of the skin material (9) supplied between the upper and lower molds (1, 2) is sucked through the vacuum hole (6) so that the periphery of the lower mold projection (3) coincides with the lower mold projection (3). Adsorb to the mold (2) surface. In addition, the peripheral part of the skin material outside the surface of the molded product is pressed and held by a pin (10) provided in the lower mold.

The lower mold (2) is raised at a speed of 200 mm / sec. When the cavity clearance between the upper mold surface and the lower mold surface becomes 50 mm, the lower mold raising speed is increased to 5 mm / sec. The molten resin (8) obtained by heating and melting the thermoplastic resin at 190 ° C. is started to be supplied between the skin material (9) and the upper mold (1) through the resin passage (7) provided in the upper mold. ,
The supply is completed when the clearance is 25 mm. When the lower mold (2) is further raised, the molten resin (8) flows, reaches the end of the cavity, is filled in the mold, clamped and shaped. The clearance between the upper and lower molds at the time of final mold clamping is 3.0 mm. Here, after pressurizing and cooling for 40 seconds, when the target molded product is taken out, there are no wrinkles or tears on the surface, and the skin material peripheral portion fits in a predetermined position in the groove of the molded product, and the appearance is beautiful, and A multi-layer molded product having a soft feeling and a high quality feeling is obtained.

[0027]

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of an apparatus showing a molding method of the present invention.

FIG. 2 (A) is a plan view of a multilayer molded product molded in Example 1 of the present invention, and FIG. 2 (B) is a vertical cross-sectional view of a portion along AA.

FIG. 3 is a vertical sectional view of an apparatus showing a molding method of the present invention.

FIG. 4 is a plan view of a multilayer molded product molded in Example 2 of the present invention.

[Explanation of symbols]

 (1) Upper mold (2) Lower mold (3) Convex part (4) Gap (5) Concave part (6) Vacuum hole (7) Resin passage (8) Molten resin (9) Skin material (10) Pin

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Fujita 2500 Koizuka, Kojinomachi, Komono-cho, Mie-gun, Mie Prefecture Inside Nissen Chemical Co., Ltd. (72) Inventor Yuji Kamiji, Komono-cho, Mie-gun, Mie 2500 Daiichi Daikoku original character Foxzuka 2500 Nissen Chemical Co., Ltd. (72) Inventor Hiromasa Nakatsuka Hirono Nakamitsu Mie-gun Konocho 2500 Daidai original character Foxzuka 2500 Nissen Chemical Co., Ltd. JP-A-63-11312 (JP, A) JP-A-62-181111 (JP, A) JP-A-59-70568 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 43 / 00-43/58 B29C 33/00-33/76

Claims (1)

(57) [Claims] 1. A skin material and a thermoplastic resin in a molten state are supplied between an unclosed upper and lower molds, and the molded product is shaped by cooling under pressure, and the skin material is bonded to a part of the surface of the molded product. When letting
A convex portion is provided at the lower mold portion where the end of the skin material is located, a concave portion is provided at a position corresponding to the convex portion of the upper mold, and the skin is formed by vacuum suction from the gap provided at the convex portion or at the base thereof. A method for producing a multilayer molded product, wherein a peripheral edge of a material is fixed to a lower mold and molded.