JPS5889329A - Simultaneous molding by different materials - Google Patents

Abstract

PURPOSE:To obtain a simultaneous molded article by a method wherein molding forces are charged with expandable resin grains, which are heated from the side charged with a different material, the boundary sections are welded before the forces are opened, a gap is laid between the boundary sections, said gap is charged with the different material and heated and then both surfaces are heated from the charging side. CONSTITUTION:The cavity of a molding die is charged with the material of expandable thermoplastic grains, the material is heated from the side of the gap for a different material, the boundary sections at least of the molding forces are welded, the forces are not opened for a time until expanding pressure disappears, next, the molding forces are opened to make a gap with a necessary thickness on the boundary side, said gap is charged with the different material, the material is heated from the charging side and then from the reverse side also and, moreover, both sides are heated, keeps the temperature and then cooled. Thus, it is possible to obtain the simultaneous molding method suitable to save energy.

Description

[Detailed Description of the Invention] This invention relates to a simultaneous molding method for IC using different raw materials.1 Using different raw materials made of expandable thermoplastic resin particles, it is possible to integrally form KB and fuse the shapes without mixing the respective raw materials. - Therefore, in cases where energy saving is particularly required, foam molded products may be made into separate KvL shapes using raw materials made of two or more types of foamable thermoplastic resin particles, and the fitting parts may be formed by adhesive or other means. In particular, examples of the latter include conditioners, etc. When molded products made of foamed polystyrene were used as packaging materials for electrical appliances, cardboard sheets, etc., were glued to the bottom surface to prevent damage such as chipping at the lower corners, but the adhesive could come off and the integrity was compromised. Both of the above conventional techniques have a number of problems, such as high manufacturing man-hours and inefficiency.
There was a strong demand for improvements from the industry in terms of reducing costs.

For this reason, it has recently been proposed to fill expandable thermoplastic resin particles, which serve as different raw materials, in stages and mold them at the same time. i) Different types of raw materials may be mixed together during the filling process, which has the disadvantage that it is difficult to form clear boundaries. A forming method has also been proposed in which one of the different types of raw material is first heated and cooled to temporarily fuse it, and then molded to fill the other type of raw material, but in this case, The expansion pressure is suppressed by cooling after heating, and when the boundary part also undergoes a degree of fusion, the temporarily fused material and the mold also become cooled IIK reeds, and the next different type is heated after filling the other raw material. The process requires a large amount of thermal energy, which is not preferable in terms of efficiency in terms of foaming L shape. A method of simultaneous molding using different raw materials that can eliminate various drawbacks at once is an undeveloped method that has been extensively researched, and the method is as follows.
In a method of obtaining a foamed molded product by filling a raw material made of expandable thermoplastic resin particles into the mold cavity of a mold and heating and expanding the raw material with a heating medium such as steam, the first raw material is first poured into the mold cavity. After filling the mold, heat is applied from the side where the gap for the different materials is to be created, and at least the boundary part is finished by heat fusion, and then the foaming pressure is removed without forming the mold N for a while. Then, the mold is opened by the required interval 1 to create a gap on the side that will become the boundary, and a raw material different from the raw material is filled in the gap, and heating is performed from the side filled with the different raw material. After that, heating is performed on one side from the opposite direction, and after heating on both sides, heat retention and cooling are performed to obtain a simultaneous molded product in which the whole is fused and molded as one piece.

Next, to describe this embodiment in detail,
After filling the cavity mold and the pour mold with 11VU, the mold cavity was first filled with expandable thermoplastic resin particles, which will be the first raw material among the 11 raw materials.Next, a gap was created for other different raw materials. For example, when trying to supply other different raw materials from the cavity side, add one side from the cavity side,
Heat is applied to fuse the first filled resin particles to each other (both boundary areas are heated and fused, and the mold is left for a while without opening until the foaming pressure is removed). This will help retain heat.Next, while spraying ejector 1- onto the molded product side, open the capity mold by the required distance and place it on the boundary side, which in this case will be fused by light. I am busy trying to find a gap between the one type and the capacity type, and fill this gap with the other expandable thermoplastic 411m# particles, which are different in terms of the initial raw material. a [Heating is performed on one side from the cavity side, which is the side where the raw material is filled, and on the other side, the resin particles are fused together), and then the opposite KJ is applied.
Heating is performed from the A side, and then heating is performed.
For cooling, water cooling is performed, and after draining water, the mold is left to cool.After cooling, the mold is quickly opened, the mold is released, and the mold is completely opened to take out the molded product at the same time. In the figure, a cushioning material used at the bottom of machines, instruments, and devices 141 when they are packaged is shown as a specific example of a simultaneously molded product. Of this foamed VL-shaped product (6), (,) and (a) are parts composed of raw materials of foamable thermoplastic resin particles that are different from each other, especially (5).
Reference numeral 5 denotes a portion having the required thickness at least at the bottom of the foam molded product (2), and in FIG.
In addition, FIG. 3 shows a case in which the required thickness of the eye side portion is also reached. (s) The part (a) is molded at the same time without mixing different materials, and the boundary parts are fused together. Example-
The reason for this is that foamed polystyrene resin is relatively inexpensive. However, foamed polyolefin resin is superior in terms of flexibility, elasticity (restorability), and oil resistance, so these effects can be utilized at least in the required thickness at the bottom of the foamed molded product. Therefore, in the above case, a wide variety of foam molded products can be used, at least at the part corresponding to the required thickness of the bottom part, depending on the required function, for example, by reinforcing this part and making corners. It is possible to sufficiently add value to foamed molded products, such as those that have eliminated damage, chips, etc., and those that have increased durability by imparting chemical resistance.Therefore, in the case of the above-mentioned packaging materials for electrical appliances such as air conditioners, Partial reinforcement can be achieved without attaching a cardboard sheet to the bottom surface of the foam molded product as in the past.K
Become.

Examples of foamed polyolefin resins include polyolefin resins such as ethylene homopolymer, ethylene-vinyl acetate copolymer, propylene homopolymer, or the polyolefin resin and styrene,
Homopolymer of methylstyrene, styrene-acryloni′
It also includes mixed resins of PJA/4I with polystyrene resins. In particular, styrenic monomers and monomers with polyolefin particles such as polyethylene and polypropylene as cores! The catalyst for polymerizing - is collected in the #KQlj core, and the styrene-based mono! - By polymerizing the polyolefin resin and the polystyrene resin, a blowing agent is added to the resin particles in which at least a portion of the polyolefin resin and the polystyrene resin are graft-bonded (1% or more of the total of the polyolefin resin and the polystyrene resin). In addition, when used with foamed resin particles [trade name: Biocelan (grafting rate 4%), manufactured by Sekisui Plastics Co., Ltd.], it has high flexibility and elasticity as well as excellent oil resistance. It is preferable that it can also be given.

Furthermore, in addition to the above-mentioned co-molded products made of different materials, we also produce a large number of co-molded products with different particle sizes, different expansion ratios, and different colors. As described above, 1. With the method of this invention, it is possible to provide co-foamed molded products in various forms. In contrast, unlike conventional methods, active cooling is not performed at the stage of temporary fusion by heating, but instead heating is performed from the side where a gap for other different materials is to be created, at least for the part that will become the boundary. After completing the heat-fusion finish, the mold is left unopened for a while until the foaming pressure is released, so that the degree of fusion at the border area is not insufficient, and the next filling of raw materials is done. Even if the mold is opened for the required interval, it is possible to eliminate the phenomenon of small collapse at the boundary portion. In addition, as mentioned above (since the first filling raw material is not cooled after heating, the thermal energy from the heating applied to the first different type of raw material is a'#), and the next time after filling the raw material is heated efficiently. In fact),
In addition to being an effective method for saving energy, it also helps shorten the molding cycle, allowing simultaneous foaming molding to be carried out efficiently.

〔Example〕

Below is a length of 40cm (1■ x width $00■) as a cushioning packaging material.
An example will be shown in which a foam molded product having a thickness of 1110 m is simultaneously molded using sO times expanded polystyrene resin particles and 80 times expanded expanded polystyrene resin particles.

The following margins (process) c time] (1) IJ! Close (2) 1st raw material filling 60 times expanded resin particles
Leave for 12 seconds (4) Until foaming pressure disappears 60 seconds (0 2nd raw material filling 80
Double expanded resin particles 8 seconds■ On the other hand, heating
From the capitivity side: 6 seconds G, 6 instant/jKte) Double-sided heating Both capity and core
6 seconds side 1.0 Immediately/jKte (To) Heat retention 8
Second I Water cooling 16 seconds @ Drain 3 seconds O
Cooling 0 10 seconds 9 Quick open 29 yen Opening
Cool ■ 120 seconds - release mold
0.1 instant/dKte(1?)! ! Open 7 seconds (
Type II close 2 seconds

[Brief explanation of the drawing]

The figures show several examples of simultaneously molded products molded by the method of this invention. Figure 2 is a cross-sectional view of a case where only the bottom part is made of a different type of raw material than the other parts. They are a cross-sectional view when different kinds of raw materials are used for the side parts as well as the bottom, and a cross-sectional view when different kinds of raw materials are used for the IM8 side part and the bottom sK. (2)・-M-shaped foamed product by simultaneous molding (-1)...
Parts composed of mutually different raw materials

Claims (1)

[Claims] 1. In the method of obtaining a foam molded product by filling the cavity of a U-shaped mold with a raw material consisting of a foamable thermoplastic resin layer and particles, and heating and expanding the raw material with a heating medium such as steam, the first step is After filling the raw material into the mold cavity, heat is applied from the side where a gap for other different materials is to be created, and at least the boundary area is heated and fused, and then heated for a while. The mold is left unopened until the foaming pressure is exhausted, then the mold is opened by the required distance to create a gap on the boundary side, and the gap is filled with a raw material that is different from the raw material, and After heating on one side from the filling side of the raw material, heating on one side from the opposite direction, then heating on both sides, heat retention and cooling, and simultaneous molding where the whole is fused into a VT shape. Simultaneous molding method using different raw materials characterized by obtaining a product 0