JPH03161313A - Monolithic molding method for surface-decorated molding - Google Patents

Abstract

PURPOSE:To obtain a surface-decorated molding which is superior in any of an external appearance, a quality and productivity, by a method wherein a sheetlike double layer material where a thermoplastic film having a thickness of 30-200 mum is in between a cloth layer and foamed layer is used. CONSTITUTION:When monolithic molding of a surface-decorated molding is performed by making use of a sheetlike double-layer material 3 where there is a film between a cloth layer 4 and foamed layer 6, bubbles of the foamed layer 6 do not come off through the cloth layer 4. Since the compressed bubbles are released along with breaking of molds 7, 8, the bubbles are restored to almost size of the original bubbles. Since the bubbles of the foamed layer 6 do not come off through the cloth layer 4, melting heat of molten resin 10 is insulated and a thickness of also the cloth layer 4 is restored. Cushioning properties are kept on with cloth which is free from falling of hair or shrinkage of pile and has favorable hand.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to integral molding of decorative molded products. More specifically, the present invention relates to the integral molding of a decorative molded article that can efficiently produce a large-sized molded article that has the appearance of cloth with a good texture, has good soft cushioning properties, and has good adhesion.

[Conventional technology] In recent years, molding materials made of thermoplastic resins such as polypropylene and acrylonitrile-butadiene-styrene copolymer (ABS resin) have been used as base materials for interior parts such as automobile door trims and instrument panels. In order to provide a luxurious feel and a soft touch, a sheet-like multilayer material formed by laminating a fabric layer such as a fabric or a knitted fabric and a foamed synthetic resin layer such as a polyolefin resin is used on the molding base. Many decorative molded products are manufactured that are bonded to the surface of materials.

Conventionally, methods for manufacturing such decorative molded products include a method in which the sheet-like multilayer material is pasted in a post-process on the surface of a base material that has been previously molded into a desired shape, or a method in which the sheet-like multilayer material is pasted in a sealed mold in advance. A method of inserting a multilayer material and integrally molding it with the base resin by injection molding, or heating and softening a laminate sheet in which the base material and sheet-like multilayer material are pasted in advance and then press-molding it into the desired shape. Methods for obtaining decorative molded articles are generally known.

However, while these methods can provide a high-quality product appearance, they also require excessive manufacturing man-hours, equipment costs, and material loss for applying adhesives and pasting the multilayered material. There is an issue of production costs involved.

In order to improve these problems, a manufacturing method using a resin compression molding method has recently attracted attention as a new method for manufacturing decorative molded products in place of the above-mentioned methods. The gist of the method is to position a sheet-like multilayer material with a polyolefin resin foam layer on one side of a pair of molds that are open to each other, and place a molten resin material as a base material on the other side of the mold. After placing the required amount of the material, the mold is engaged and compressed by the mold clamping force, and the base resin is thermally fused to the back surface of the foam layer side of the sheet-like multi-layer material. This is a method of integrally molding a material and a base material into a desired shape at the same time. JP-A-62-18111 describes a molding method in which a film is provided between the base material and the foam layer.
Publication No. 3 is known.

When a fabric layer with naps is used, the foam layer that is directly fused to the base material is crushed, resulting in a decrease in cushioning properties, and the napping of the fabric layer is reduced, although this is not as bad as when using conventional injection insert molding. In many cases, the appearance quality was impaired due to the pile shrinkage, etc., and the product could not be of good quality.

Therefore, in manufacturing the decorative molded product using a raised fabric layer, prior to the present invention, it is necessary to have a good finished state in which the fabric layer does not have fluff fall or pile shrinkage, and the foam layer is not crushed. A method for manufacturing a decorative molded article was discovered and filed in Japanese Patent Application Laid-open No. 1983-Hill, which is now publicly known.

The gist of the invention of this prior application is that in the resin compression molding method already explained, the temperature of the upper mold on the side where the fabric layer is in contact is set to 1.
The temperature of the lower mold on which the base resin is placed is 10 to 2 degrees below 0℃.
The temperature was maintained at 5°C, and the holding pressure after mold clamping was 30 kg/
This was a method for integrally molding decorative molded products, characterized by molding under reduced pressure to a low pressure of less than 1000 m.

This is a method of compression molding under specific molding conditions consisting of a low temperature setting and holding pressure, and this method has achieved the effect of dramatically improving the appearance of the fabric layer after molding. Maintaining the temperature of the upper mold below 10°C in this method means that the temperature becomes lower than the dew point temperature of the air around the mold in a normal environment, and as a result, water droplets or water droplets appear on the surface of the upper mold. The film was completely adhered. Therefore, during molding, the fabric layer comes into close contact with the surface of the upper mold, so that the fabric layer surface is moistened with the water droplets or water film, and this wetting phenomenon facilitates cooling of the fabric layer. Furthermore, this also prevents the temperature rise of the foam layer on the back side of the fabric layer, effectively acting in the direction of cooling and hardening.
It was confirmed that this contributes to the appearance of the fabric layer after molding and to the elasticity retention of the foam layer.

[Problem that the invention seeks to solve]

However, if the mold is cooled too much, moisture in the air will adhere to the mold surface, and these water droplets will drip and wet the lower mold surface, which not only impairs workability but also reduces the molten resin that will become the base material. This lowered the temperature of the molten resin, impairing the fluidity of the molten resin and having an adverse effect on moldability.

On the other hand, if the mold temperature is too high, the cross-sectional structure of the fabric layer of the sheet-like multilayer material is inevitably formed with a gap structure that has air permeability, so there is no barrier effect and the sheet during mold clamping 1. The air in the foam layer cells of the multi-layer material is not sealed here and leaks to the fabric layer side. As a result, the air pressure inside the bubbles decreases, so that the heat of the molten resin and the pressing force are applied at the initial stage of mold clamping, and the bubbles in the foam layer are crushed.

Due to the collapse of the air bubbles, the thickness of the foamed layer is not restored even after the mold is opened, resulting in a product with reduced cushioning properties.

Further, since air leaks to the fabric layer side, the heat of the molten resin is transferred to the compressed fabric layer, which has an adverse effect on the fabric layer. In other words, due to the action of the heat and mold clamping pressure, a so-called ironing effect occurs, causing the fabric to fall down and the pile to shrink, and even after the mold is opened, the thickness of the fabric is not restored and the texture of the fabric layer deteriorates. This tends to result in products that are

During molding, the foam layer is destroyed, the texture of the fabric layer is reduced, and the pile shrinks due to the high temperature of the molten resin, which impairs the appearance quality and reduces product yield. It had many problems, such as low performance. On the other hand, a molding method in which the mold temperature is too low reduces the fluidity of the molten resin, and although it is suitable for molding small parts such as billers, it is difficult to mold large parts such as door trims, resulting in productivity problems. There were some drawbacks in terms of aspects.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to integrate a sheet-like reinforcing material having a foam layer and a fabric layer with a base material by a compression molding method. To provide an integral form of a decorative molded product which is excellent in appearance, quality and productivity.

[Means for solving problems]

The present invention consists of a decorative fabric layer and a foam layer. This is a method in which a sheet-shaped 'F31H material is fixed to an open molding surface, the required fl. This is an integral molding method for decorative molded products, which is characterized by using a sheet-like multilayer material with a 30-200 μm thick sweetfish plastic film between the earth layer and the foam layer.

Hereinafter, an example will be described in detail with reference to the drawings. 1st
The figure is a sectional view showing an example of a decorative molded product according to the present invention. As shown in the figure, the decorative molded product 1 is composed of a base material 2 and a sheet-like multilayer material 3, and the sheet-like RI layer material 3 is
Fabric for decoration! It is made up of an i4, a film 5, and a foam layer S, and the fabric layer 4 is always integrally molded on the outside.

The base material 2 used here is made of thermoplastic resin, and contains crystalline polypropylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, and propylene components.
Examples include crystalline polyolefin resins such as crystalline propylene-ethylene copolymers containing 0% by weight or more, acrylonitrile-butadiene-styrene copolymers, polyamide resins, polystyrene resins, etc., especially those with low specific gravity. , from the viewpoint of balance of physical properties and moldability, crystalline polypropylene, propylene Iffl content is 70%
It is effective to use polypropylene which is a crystalline propylene-ethylene copolymer containing at least % by weight. Furthermore, fillers such as talc, mica, glass fibers, synthetic fibers, carbon fibers, metal fibers, cellulose fibers, wood flour, and the like can be added to the above-mentioned resins as necessary. The thickness of the base material 2 is in the range of 1 to 4+ am, preferably 2 to 3 I. If the thickness is less than 1 mm, the fluidity during compression molding will be poor and the shape will not be obtained, and the rigidity of the decorative molded product will be insufficient and it will be easily deformed. If the thickness exceeds 4 mm, the weight of the decorative molded product will increase. It also increases the cost.

The sheet-like multilayer material 3 is constituted by a three-layer laminate formed by pasting a fabric ya4, a film 5, and an emitting layer 6, respectively. When attaching sheet-like multilayer materials, use materials that have already been integrated by laminating.

A feature of the present invention is that there is a film 5 between the fabric layer 4 and the foamed FJe, and this film 5 is made of a flexible and stretchable thermoplastic resin with a thickness of 30 to 200 μ
film or sheet. Preferred materials include polypropylene, polyethylene such as low density polyethylene, polyolefin thermoplastic elastomer, ethylene-vinyl acetate copolymer, and flexible polyvinyl chloride. The film 5 is particularly preferably made of random block copolymer-based polypropylene or soft polyvinyl chloride and has a thickness of 50 to 150 μm. If the thickness is less than 30 μm, the film will be torn due to the bubble pressure during compression molding, which will adversely affect the foam layer 6 and the fabric layer 4. On the other hand, if the thickness exceeds 200μ, the soft feel of the decorative molded product 1 will be reduced and the cost will increase.

The fabric layer 4 used in the present invention is a decorative layer that determines a high-class appearance, texture, and touch, and is a woven fabric, a nonwoven fabric, or a knitted fabric, and among them, a fabric having a raised surface is preferable. Specifically, woven or knitted fabrics such as tricot, Mogat, jersey, and plain weave fabrics made of synthetic fibers such as polyester fibers, polyamide, polyacrylonitrile, and vinylon, and which have raised or piled surfaces are preferred.

Further, fabrics made of wool, cotton, and rayon, fabrics woven with blended yarns of these and synthetic fibers, or nonwoven fabrics made of polypropylene or polyester fibers may be used.

The foam layer 6 of the present invention is a foam layer made of thermoplastic resin, and constitutes the back surface of the sheet-like multilayer material 3.

Examples of the material for the foam layer include flexible foam sheets such as foam polypropylene, foam polyurethane, foam polyethylene, and foam polyvinyl chloride. From the viewpoint of cushioning properties, a foam layer 6 with a foaming ratio of 10 to 40 times and a thickness of 2 to 5 mm is preferable. Especially base material layer 2 and foaming! In terms of adhesiveness with I6, when the base layer 2 is made of polypropylene, it is preferable to use a material of the same quality, such as foamed polypropylene.

In the integral molding method of the present invention, (1) a mold attached to a compression molding machine and kept at a predetermined constant temperature is open and on standby;

■Fix the previously cut sheet-like multilayer material 3 to the open molding surface. (Fig. 2) ■ Place the required amount of molten resin 10 between the opened molds. ■The mold is compressed and clamped at a predetermined pressure for a predetermined time. (Fig. 3) ■Then, the mold is released and the obtained molded product is taken out. ■Sheet-like multilayer material 3
An example of an integral molding method for obtaining the decorative molded product 1 by cutting off unnecessary portions of the periphery of the decorative molded product 1 can be exemplified.

The compression molding machine used in the present invention is one in which clamping speed, clamping pressure, and mold temperature can be controlled.

It is preferable to use a mold that can quickly close the mold and automatically set high pressure maintenance of 50 to 100 kg/cm' and low pressure maintenance of 5 to 30 kg/cm'. Opening is best, but horizontal opening is also acceptable.

The molds 7 and 8 are preferably molds whose temperature can be set arbitrarily;
It is best to use one that allows cooling water and constant temperature water to flow through it.

The molding area of the mold may be approximately 200 cm for a small part, such as a door trim, or GOOOc+a' for a large part, such as a door trim.As for the mold temperature, the cooling efficiency of the molten resin 10 is good when the temperature is low; If the temperature is too high, the molten resin 10 in contact with the surface of the mold 8 during mold clamping will be cooled too much, resulting in loss of fluidity and hindering moldability.On the other hand, if the temperature is too high, the fabric layer 4
Falling of the fibers and coarsening of the fabric (the fabric becomes open and clay-like) occur, and the elasticity of the foamed layer 6 also decreases significantly, impairing the appearance, feel, and elasticity of the fabric. This appropriate temperature range is preferably 20 to 60°C. The mold temperature is
The mold 7 on the sheet-like multilayer material side and the mold 8 on the molten resin side may have the same setting, but in order to strongly cool the sheet-like multilayer material 3, which is difficult to cool, the mold 7 on the sheet-form multilayer material side is It is preferable to set the temperature at least 20° C. lower than the mold 8 on the resin side. In order to improve the fluidity of the molten resin 10, it is preferable to set the temperature of the mold 8 on the molten resin side to a higher temperature than the mold 7 on the sheet-like multilayer material side to improve moldability. By setting the mold on the sheet-like multilayer material side 7 to a low temperature, a further effect can be expected in maintaining the appearance quality of the fabric layer.

Taking FIG. 2 as an example, the sheet-like facing material 3 is fixed with the fabric FJa side facing outward and in contact with the molding surface of the upper mold 7. The fixing method is vacuum suction at the periphery of the upper mold 7,
Alternatively, an appropriate method such as clipping or pinning can be used.

A required amount of molten resin 10 is placed between the open molds. The method of placing between the molds includes sheet-like surface placement, line placement, and dot placement, and a predetermined amount may be placed in a predetermined position under control with a muffler or the like. The amount of molten resin 10 is determined by the size of the molded product and its thickness.

Next, the mold is clamped. (Figure 3) For mold clamping,
Pressure increase, pressure holding, pressure reduction, and combinations thereof are performed. At the start of mold clamping, the mold clamping pressure is 50 to 100 kg/c,
After reaching the set pressure, hold it for 5 to 20 seconds, then reduce the mold clamping pressure to 5 to 30 kg/cm" and tighten to 10 to 60 kg/cm".
I can give an example of how to hold it for seconds.

After integral molding under the above conditions, the mold is opened and a molded product of a predetermined shape is taken out.

An example of an integral molding method for obtaining the decorative molded product 1 can be given by cutting off unnecessary portions of the periphery of a molded product having a predetermined shape.

[Effect]

In the integral molding of the present invention, the sheet-like multilayer material 3 and the molten resin 10 are fused and integrated by mold clamping.

When the mold is clamped, the sheet-like multilayer material 3 and the molten resin 10 are pushed into the mold gap. By clamping the mold, the molten resin spreads and becomes a molded product with a predetermined shape and thickness. For example, if the mold gap is 3.2H, the thickness of the sheet-like composite material is about 5 am (2
When mold-clamping molten resin 10 with a set thickness of 2.5cm and fabric layer of 80μ thick, 80μ film, and foam layer of 3cm, a total of 7.5cm of sheet-like multilayer material and molten resin will be molded into gold. Mold gap 3.2
■You will be forced into.

The thickness of the 2.5 mm molten resin 10 does not change even when compressed, so the mold gap 3. : The difference between 2+m and the molten resin 2.51 is 0.7InIl, about 5+! The sheet-like composite material 3 of m is compressed, and the sheet-like composite FF material is foamed! The compressive force of the air bubbles in J6 and the fibers in fabric layer 4 causes the sheet-like F
The mB material 3 and the molten resin 10 are pressed together.

Without a film between the foam layer and the fabric layer, there is nothing to seal with and the air bubbles in the foam layer will escape through the fabric layer. As a result, the foam layer becomes thin, has no cushioning properties, and becomes a decorative piece of the fabric layer with poor appearance due to falling hair and shrinkage of the pile.

On the other hand, fabric! Film 5 between J4 and foam layer 6
Is there a sheet? If the one-layer material 3 is integrally molded, the air bubbles in the foam layer 6 will not escape from the fabric layer 4. When the mold is opened, the compressed bubbles are released, and the bubbles return to almost their original size. The foamed Fl8 bubbles are
Since it does not come out of the fabric layer 4, it insulates the melting heat of the molten resin 10 and restores the thickness of the fabric layer 4. The fabric has a good texture and maintains its cushioning properties without falling or shrinking the pile. The spread molten resin 10 is cooled and becomes the base material 2.

〔Example〕

Next, an embodiment of the method for manufacturing the decorative molded product 1 will be described based on FIGS. 2 and 3 showing the manufacturing process of the decorative molded product of the present invention.

In this embodiment, the sheet-like multilayer material 3 includes a tricot weave fabric layer (approximately 2 mm thick) made of polyester fibers and having a raised surface, and a barrier made of soft polyvinyl chloride with a thickness of 80 μm on the back side. Film 5 is attached,
Furthermore, on the back side of this barrier film 5, a foaming ratio of 20 times,
It is a three-layer laminate (total thickness approximately 5 sum) to which a 3 cm thick cross-linked polypropylene foam Fl6 is adhered. The molten resin 10 forming the base material 2 is a filler composite polypropylene made by Chisso (density: 1.05 g), which has excellent mechanical properties such as rigidity and impact resistance, and is suitable for compression moldability.
/cm”, Melt Fluorate 3 8g/10 min
), so that the thickness of the base material 2 is 2.5 cm,
The amount of charge of molten resin lO was set in advance.

First, the above-mentioned sheet-like multilayer material 3 is cut into a desired shape and then attached to a predetermined position of the upper die 7 of the molding machine, which is open and waiting vertically facing each other, as shown in FIG. At this time, the sheet-like multilayer material 3 is placed on the upper mold 7 with the fabric layer 4 side facing upward.
placed in contact with the molding surface.

Next, a resin pouring nozzle 9 attached to the tip of the extruder (not shown) enters between the upper mold 7 and the lower mold 8, and moves relatively according to the shape of the molded product. Then, a required amount of molten polypropylene resin 10 is charged and placed within the molding surface area of the lower mold 8.

Thereafter, the resin pouring nozzle 9 is moved out of the mold, and the upper mold 7 and the lower mold 8 are immediately engaged to perform mold clamping. By this mold clamping, as shown in FIG. 3, the molten resin 10 is pressurized into a shape along the cavity formed between the upper mold 7 and the lower mold 8, and The base material 2 having a predetermined shape is formed by cooling and solidifying using the mold 7 and the lower mold 8. At the same time, the sheet-like composite material 3 is integrally molded with the base material 2.

Here, in this embodiment, the mold gap of the cavity is set to 3.
Since it was set to be 2■1, subtracting the thickness of base material 2, 2.5ml1, from this, the sheet-like multilayer material 3 becomes 0.
．． This means that the mold is held in a compressed state of 7 m². This is approximately 1 of the original thickness of the sheet-like multilayer material 3, 5 cm.
This corresponds to 4%.

Next, after opening the upper mold 7 from the lower mold 8, the molded product in which the base material 2 and the sheet-like multilayer material 3 are integrated is taken out from the mold, and the unnecessary portion of the periphery of the sheet-like multilayer material 3 is removed. Excise it and
A decorative molded product 1 having a cross-sectional shape as shown in FIG. 1 is obtained.

When observing the appearance of the decorative molded product 1, it was found that the fabric layer 4 had little hair fall and pile shrinkage, had a soft feel, and had good appearance quality without impairing the feel of tricot. Next, when observing the cross section of the decorative molded product 1, the measurement result of the thickness distribution of the polypropylene base material 2 was 2.5 ± 0.
．． It is molded to have an almost uniform thickness of 1 mm. Except for the interface layer that is thermally fused to the molten resin 10, the foamed polypropylene layer 6 was found to maintain almost its original shape with few crushed cells, and the average thickness of the foamed layer 6 was approximately 2.4 mm. 3, which shows a thickness restoration rate of about 80% with respect to the original thickness of 3. Furthermore, the fabric layer 4, including the raised part, has a thickness of approximately 1.8
It has a thickness of t++ and exhibits a thickness recovery rate of 90% or more.

In this way, the film 5 has no tears as a whole, and the foamed M
6. It plays the role of protecting the fabric layer 4.

The molding conditions in this example were set as follows.

0 Charging temperature of molten resin 10: 200 to 205°C B Temperature of upper mold 7: 25°C B Temperature of lower mold 8: 60°C B Mold clamping initial pressure: 75 kg/am”0 Holding pressure: 1 5 kg/cm” mold clamping retention time
:35sec [Comparative example] Except for using a sheet-like multilayer material consisting of a two-layer laminate in which a fabric layer and a foam layer were directly attached without using a film.
Molding was carried out under the same conditions as in the previous example.

When we observed the finished decorative molded product, we found that the foam layer had been crushed considerably, and its thickness had collapsed to about 0.8 m (less than 1+n+) (the thickness recovery rate was about 30%), and the Kutz's toughness was extremely poor. Not only has the fabric been damaged, but small dents have appeared all over the fabric surface, the hair has fallen and the pile has shrunk, and the thickness of the fabric layer has decreased to an average of about 1 inch (thickness recovery rate). Approximately 50%) The product had poor appearance quality.

〔Effect of the invention〕

In the integral molding method of the present invention, since the film is interposed between the fabric layer and the foam layer, the air bubbles in the foam layer do not come out from the fabric layer even if they are integrally molded by mold clamping force. For this reason, the foam layer thickness of the sheet-like multilayer material before molding was 3 cm, but the foam layer thickness of the decorative molded product using the conventional molding method was 0.5 cm. 8mm, whereas the foam layer thickness of the present invention is 2.4■,
It had good cushioning properties.

In the integral molding method of the present invention, since the film is interposed between the fabric layer and the foam layer, the foam layer remains and does not transmit the melting heat of the base material to the fabric layer. For this reason, the fabric layer thickness of the sheet-like multilayer material before molding was 2cm, whereas the fabric layer thickness of the decorative molded product using the conventional molding method was 1cm, whereas the fabric layer thickness of the fabric layer of the present invention was The layer thickness was 1.8 m, and a product with a good appearance was obtained without falling hair or pile shrinkage.

In the integral molding method of the present invention, since the film is interposed between the fabric layer and the foam layer, the air bubbles in the foam layer do not escape from the fabric layer during molding. For this reason, molding can be carried out in a room temperature mold, unlike conventional molding which is carried out in a low temperature mold of 10° C. or lower in order to prevent foam layer bubbles from coming out of the fabric layer. The integral molding method of the present invention, in which the molten resin has good fluidity, can efficiently and easily produce large parts such as doors and IJs with a molding area of about 8,000 cm.

In this way, integral molding using a sheet-like multilayer material in which the film of the present invention is interposed prevents the foam layer and the fabric layer from being crushed, and there is no need to use a low-temperature mold. For this reason, Khushi.
This integral molding method has a good external appearance with good softness, fit, and soft feel, and can be suitably used as decorative molded products for high-class automobile interiors and other decorative molded products.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the decorative molded product according to the present invention, and FIGS. 2 and 3 are drawings explaining the manufacturing process of the decorative molded product of the present invention. 3 is an elevational view of the main parts of the molding machine showing the state in which the sheet-like multilayer material and molten resin are placed on the mold before mold clamping, and FIG. 3 is a sectional view of the mold showing the molding state during mold clamping. DESCRIPTION OF SYMBOLS 1... Display molded product, 2... Base material, 3... Sheet-like multilayer material, 4... Fabric layer, 5... Film, 6...
- Foaming layer, 7... Upper mold, 8... Lower mold, 8...
Resin pouring nozzle, 10...molten resin or more

Claims (1)

[Claims] A sheet-like multilayer material consisting of a fabric layer for decoration and a foam layer is fixed to an open molding surface, and after placing the required amount of molten resin as a base material on the opposite molding surface, molding is performed by clamping the mold. 1. A method for integrally molding a decorative molded article, the method comprising using a sheet-like multilayer material having a thermoplastic film of 30 to 200 μm between a fabric layer and a foam layer.