JPH04338517A - Manufacture of multi-layer molded product and its device - Google Patents

Abstract

PURPOSE:To develop the manufacturing method and its device for manufacturing a skin integrated molded product composed of a skin and core material resin without lowering the good hand of skin in the skin insert molding in which a conventional injection molding machine provided with a mold clamping device moving horizontally is used. CONSTITUTION:A molding device consists of a female mold 3 and a male mold 4, and the male mold is composed of a skin fixing frame 6 for clamping a skin material 11 and slide core blocks 1 and 2 corresponding to the product surface and compressing and developing molten resin injected into the male mold. Said slide core blocks are operated by a hydraulic cylinder, and molten resin is compressed with a proper pressure to integrate the resin to form a core with the skin. The slide core blocks are composed of two units and a block unit 1 is constituted by two pieces. The molten resin is pressed out into a space to be formed when the block 1 is moved backward, and then pressed by moving the block 1 forward.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a multilayer molded article in which a skin and a core resin are integrated. More specifically, a normal injection molding machine equipped with a mold clamping device that moves in the horizontal direction is used to press the molten resin injected into the mold with appropriate pressure to create a skin with a good surface condition. The present invention relates to a method for manufacturing a multilayer molded product in which a core resin and a core resin are integrated, and an apparatus therefor.

0002

[Prior Art] As is well known, plastic molded products have excellent shapeability, light weight, and mechanical properties, and are also inexpensive, so they are manufactured industrially as various parts or products, such as automobiles, It is used in many ways as home appliances and daily necessities. However, on the other hand, it has drawbacks such as a cheap appearance and being easily scratched. To solve these problems, it is common practice to paint the surface of the plastic molded product or to attach a skin such as PVC leather or cloth with an adhesive. Since this method involves post-processing after molding, there are restrictions on shape, and a large number of work steps and equipment are required, resulting in extra labor and increased costs.

[0003] As a measure to improve this, in recent years, a so-called method has been developed in which a skin material is set in a mold for the purpose of protecting and decorating the surface of a plastic molded product, and then a molten resin material is poured in to integrate the skin and core resin material. Various types of skin-insert molding have been implemented.

[0004] However, there have been proposals to integrate a fabric such as a woven fabric or a non-woven fabric into the skin using a general injection molding machine (Japanese Patent Laid-Open Nos. 109659-1982 and 31256-1980);
Using PVC leather lined with foam sheet,
There are proposals for methods such as integral molding by injecting a resin material as a core material. However, when using these methods, the injection pressure of the resin material is too high, the skin material is damaged by the temperature of the molten resin, and the texture is impaired, so that the original purpose cannot be achieved.

[0005] In order to solve these problems,
The method proposed in No. 2-297123 is to set a cloth in a mold, supply plasticized and molten resin between the lower mold and the cloth, lower the upper mold, and press the molten resin at low pressure. This is a method to obtain a skin-integrated molded product, but this method has the disadvantage that resin overflows at the end of the molded product, and when using a general-purpose injection molding machine in which the mold moves horizontally, the structure The disadvantages are that sufficient low-pressure pressing is not possible, and because the molten resin is supplied with the mold open, the molten resin is supplied biased downward due to gravity.

[0006]

[Problems to be Solved by the Invention] The present invention can also be applied to large-sized molded products, and the skin material is lined with a cushioning material such as woven fabric, non-woven fabric, or PVC sheet, or in some cases, foamed sheet. When integrally molding with the resin that serves as the core material, the damage to the skin caused by the temperature of the molten resin and the pressure for injection (decreased texture, wrinkles, resin leakage) is solved. The purpose of this study was to develop a manufacturing method and apparatus for obtaining a skin-integrated molded product in which the skin and core material maintain good adhesion.

[0007]

[Means for Solving the Problems] In manufacturing a multilayer molded product using a molding device consisting of a female die and a male die that move in the horizontal direction, the male die has a slide core block structure that moves back and forth. , and the slide core block consists of a block 1 and a block 2 each having a resin supply port, and the block 2 is structured to move a predetermined distance behind the movement of the block 1, and the male mold can be opened and closed, In addition, a skin material fixing frame is provided which has an opening for the male slide core block to pass through, and if necessary, the male mold can be inserted into the skin material with the periphery of the skin material sandwiched between the fixing frame and the male mold. The slide core block is advanced, the skin material is pre-shaped, the male slide core block is retreated, the female mold and the male mold are closed, and the skin material and the male mold are separated with block 1 delayed by the predetermined distance. A predetermined amount of the core molten resin is supplied through the resin supply port of the block 1 between the block 1 and the block 1, and then the block 1 and the block 2 are moved forward together, and the core molten resin and the skin material are press-molded. In the method for manufacturing a multilayer molded product and the multilayer molded product device comprising a female mold and a male mold that move in the horizontal direction, the male mold has a built-in slide block that can move back and forth, and the slide core The block consists of block 1 and block 2, which are equipped with a molten resin supply port, and block 2 responds to the movement of block 1.
Provided is a multilayer molding device that has a structure that moves with a delay within a predetermined distance range, and further includes a skin material fixing frame that can be opened and closed and has an opening for a slide block to pass through. It is something to do.

[0008]

[Operation] Hereinafter, the present invention will be explained in detail with reference to the drawings showing specific examples of the apparatus used in the present invention.

FIGS. 1 to 4 show one of the molding apparatuses used in the present invention.
1 is a cross-sectional view showing an example, the device consisting of a horizontally placed female die 3 and a male die 4, which together form a molding device; FIG. FIG. 5 shows a sectional view taken along line AA in FIG.

[0010] This molding apparatus can be attached to a general-purpose injection molding machine having a mold clamping device that moves in the horizontal direction. The female mold 3 has a recess 5 corresponding to the shape of the molded product, and also has a recess 7 for housing a skin fixing frame 6 attached to the male mold 4.

The male die 4 includes a slide core block 1 and a slide core block 2 whose molding surface corresponding to the product surface is movable by a hydraulic cylinder, and the slide core block 1 is attached to the male die 4 or a fixed type sheet of the molding machine. It is connected to the rod 15 of a fixed hydraulic cylinder (Fig. 514), and has a structure in which it slides back and forth by the hydraulic cylinder 14.

The slide core block 1 is also provided with a supply hole 8 for injecting molten resin into the mold.

Further, the male mold 4 is provided with a skin fixing plate 6 which can be clamped between the male mold 4 and the male mold 4 with a fixed pressure of 0.5 to 3.5 kg/cm2, although the peripheral edge of the skin is not fixed. We are prepared.

The skin fixing plate 6 is, for example, a rod 1 of a cylinder 9 fixed to the male mold 4 and movable by air or hydraulic pressure.
0, and can be structured to move back and forth using a cylinder.

[0015] In order to manufacture a molded product in which the skin and the core resin are integrated using this apparatus, first, as shown in FIG. After clamping with pressure, the slide core block 1 is advanced to a predetermined position using the hydraulic cylinder 14 as shown in FIG. Send it out until it reaches the area. In this case, depending on the skin material, this step may be omitted, the skin may be preformed into the shape of the molded product, or the skin may only be fed out to the area required for the molded product. . Next, the female mold 3 and the male mold 4 are closed, and as shown in FIG.
The molten resin 12 is injected into the space of the slide core block 2 created by the retreat of the slide core block 2.

Next, as shown in FIG. 4, the slide core block 1 is advanced by a hydraulic cylinder 14, and while pushing out the molten resin 12 injected into the space 13 of the slide core block 2, the slide core block 1 is moved forward together with the slide core block 2 to a predetermined position. A molded product integrated with the skin material 11 can be obtained.

The size of the space 13 does not need to be large enough to accommodate the entire amount of the molten resin, and the space 13 formed at the tips of the blocks 1 and 2 can be filled as long as there is no dripping as shown in FIG. It is sufficient if the molten resin is retained.

After holding the resin in this way, block 1
The tip of the block 2 moves to the tip of the block 2, and blocks 1 and 2 immediately move together to the female mold surface, thereby preventing the resin from dripping. If this space 13 does not exist, and the molten resin is injected at low pressure, it will take time until the entire amount is injected, causing the molten resin to drip. Furthermore, when injecting at high pressure to shorten this time, the texture of the skin may be impaired, wrinkles may appear, and resin may leak.

[0019] The skin material used in the present invention is as follows:
There are no particular restrictions on the surface properties of plastic products, such as improving the appearance or making them less likely to be scratched, but they are generally made of leather, artificial leather, woven fabric, or non-woven fabric, and are further lined with a packing material on the back side. Alternatively, the back side may be laminated with other woven fabrics, nonwoven fabrics, thermoplastic resin or elastomer sheets, films, various foams, paper, etc. Preheating may be performed prior to supply, and the skin material is supplied so that the surface that will become the surface is in contact with the cavity surface of the female mold.

Further, as the core resin used in the present invention, any resin commonly used in injection molding or extrusion molding can be used. For example, polypropylene, polyethylene, polystyrene, acrylonitrile-styrene-butadiene block copolymer, thermoplastic resin such as nylon, ethylene-propylene block copolymer,
Thermoplastic elastomers such as styrene-butadiene block copolymers, thermosetting resins such as epoxy resins and phenolic resins, various vulcanized synthetic rubbers, non-foamable or foamable resins such as urethane for RIM molding, and their inorganic materials. Those containing additives such as fillers, fillers such as glass fibers, pigments, lubricants, and antistatic agents can be used.

[0021] The operating temperature varies depending on the type of resin used as the skin material and the core material, and these should be selected according to the common sense of those skilled in the art.

[0022]

[Example] The molding device shown in Fig. 1 (height 180 mm, width 3
After attaching a box-shaped product mold (50 mm, maximum height 50 mm, thickness 2.5 m, each vertex and side consisting of a constant circular arc) to a general-purpose injection molding device with a mold clamping device that moves in the horizontal direction, With the skin fixing frame 6 open, a skin material 11 (1.1 mm thick woven fabric: tricot) was inserted between the skin fixing frame 6 and the male mold 4. Next, the pneumatic cylinder 9 is moved to close the skin fixing frame 6, and the inserted skin material 11 is inserted into the male mold 4.
It was clamped at a fixed pressure of 3 kg/cm2 between the two. In this state, the slide core block 1 is advanced to a predetermined position using the hydraulic cylinder 14, and the skin material 11 is attached to the skin fixing frame 6.
and the male die 4 (Figure 2). Next, after closing the female mold 3 and male mold 4, the slide core block 1 was retreated to a predetermined position using the hydraulic cylinder 14.

A molten resin [polypropylene homopolymer (melt flow index 10 g/10 min.
30℃/2.16Kg load〉) Showaromer MA51
0, Showa Denko Co., Ltd.] (Fig. 3), then the slide core block 1 is advanced by the hydraulic cylinder 14, and while pushing out the resin from the space 13, it is pressed together with the slide block at a pressure of 35 kg/cm2. The skin material and core material are integrally molded (Figure 4). As a result, a good multilayer molded product was obtained without impairing the texture of the skin material and without wrinkles or tears in the skin.

(Comparative Example) Slide core block 1 and slide core block 2 of the molding apparatus shown in FIG. The molten resin was injected and pressed under the same operations and conditions as in the example except that the space 13 was not formed, and the skin and core material were integrally molded. The thickness of the resulting molded product is uneven (
The skin was uneven (uneven), and some wrinkles appeared on the epidermis.

[0025]

The present invention has developed a method for producing a multilayer molded product using a horizontal device to perform skin insert molding while preventing sagging of the molten resin, and an apparatus therefor.

The horizontal type has the advantage that the height of the apparatus can be kept low compared to the vertical type, large-sized molded products can be manufactured easily, and the product can be easily taken out after molding. However, the problem with the horizontal forming machine is that the molten resin drips, making it difficult to uniformly supply the molten resin to the skin.However, the present invention has improved this by using two slides installed inside the male mold that move back and forth. This problem was solved by using a core block and providing a space in the block 2 for the molten resin to accumulate, and by selecting the location of this space and the resin temperature, skin insert molding was made possible at low pressure.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the multilayer molding apparatus of the present invention, showing a state in which a skin material is held between the layers.

FIG. 2 shows a state in which the slide core block 1 is moved forward following FIG. 1 and the skin material 11 is sent out.

[Fig. 3] Subsequently, the slide core block 1 is retreated,
A state in which molten resin (core material) 12 is injected into space 13 is shown.

FIG. 4 shows a state in which the molten resin 12 is uniformly press-molded between the skin material 11 and the slide core blocks 1 and 2 while being extruded into the space 13.

FIG. 5 is a cross section taken along line A-A in FIG. 4 (when the mold is opened).

[Explanation of symbols]

1 Slide core block 1 2 Slide core block 2 3 Female type 4 Male type 5 Recess 6 Epidermis fixing frame 7 Recess 8 Resin supply hole 9 Cylinder 10 Rod 11 Skin material 12 Molten resin (core material) 13 Space 14 Hydraulic cylinder 15 Rod 16 Guide pin 17 Guide groove

Claims (4)

[Claims] Claim 1: In manufacturing a multilayer molded product using a molding device consisting of a female die and a male die that move in the horizontal direction, the male die has a slide core block structure that moves back and forth, and the slide core block is made of resin. It consists of a block 1 and a block 2 each having a supply port, and the block 2 is structured to move a predetermined distance behind the movement of block 1.
The male mold is provided with a skin material fixing frame that can be opened and closed and has an opening for the male slide core block to pass through, and if necessary, a skin material fixing frame can be inserted between the fixing frame and the male mold. The male slide core block is moved forward while holding the periphery, the skin material is preformed, and then the male slide core block is retreated to close the female and male molds so that block 1 Supplying a predetermined amount of core material molten resin between the skin material and the male die through the resin supply port of block 1 while being delayed by a distance, moving block 1 forward, and then moving block 1 and block 2 forward together, A method for producing a multilayer molded product, comprising press-molding the core molten resin and the skin material. [Claim 2] The pressure of the skin material and the core material molten resin is 10~
2. The method for producing a multilayer molded product according to claim 1, wherein the weight is 100 Kg/cm2. 3. A multilayer molded product device comprising a female mold and a male mold that move in the horizontal direction, wherein the male mold has a built-in slide block that can move back and forth, and the slide core block is equipped with a molten resin supply port. Consisting of block 1 and block 2, block 2 has a structure that moves behind the movement of block 1 within a predetermined distance range, and furthermore, a slide block passes through the male mold, which can be opened and closed. A multilayer molding device that is provided with a skin material fixing frame that has an opening for the purpose. 4. The multilayer molding apparatus according to claim 2, wherein the block 2 is configured to move behind the movement of the block 1 due to guide pins and guide grooves provided on the block 1 or the block 2.