JPS5973917A - Reproducing process of cross linked plastic scrap - Google Patents

Abstract

PURPOSE:To improve natural resource economy by using as cleaning material or forming material of an extruding machine and to reutilize it economically by a method in which powdered cross linked plastic scrap is mixed with the same kind of thermoplastic which is uncross linked and is molten at specified temperature, and then it is pelletized. CONSTITUTION:Cross linked plastic scrap A [e.g. cros linked polyethylene, gel fraction value by ASTMD2765 must be equal to or more than 30%, or cross linked vinyl acetate copolymer (EVA), gel fraction value by ASTMD2765 must be equal to or more than 40%] is powdered. This powdered material is mixed with the same kind of thermoplastic which is uncross linked (B), and after said mixture is molten at extruding temperature of 150-230 deg.C, it is pelletized by cooling and solidifying. This product is excellent in adhesive wiping effect, so high cleaning effect may be obtained by less amount of resin and shorter time than by former products.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recycling crosslinked plastic scrap.

r% uJ plastic wood of polyethylene, vinyl chloride, etc.
Chemical cross-linking such as peroxide or radiation cross-linking (by radiation) allows molecules to bond with each other, and changes the properties of the molecules to strengthen heat resistance and hardness that do not soften or melt even when heated. Possess properties. In this way, various proposals have been made for the recycling of scraps that are no longer needed for cross-linked plastic products made of covalently bonded polymers with a neat network structure. There is IRE A, which is difficult to process because it does not easily gel, and in the case of compounds containing a crosslinking agent, uncrosslinked residual crosslinking agent often remains, and there is a limit to reuse.

Therefore, most of it is disposed of as industrial waste by incineration, but it also poses a pollution problem as it generates harmful gases during incineration and damages incinerators due to the vortex generated by combustion.

In the case of cross-linked polyethylene, it has also been proposed to crush it by extrusion RI and to mix this powder with polyethylene, rubber, or plastic and mold it, but forming the powder into a mold is a very difficult process.

This invention solves the above-mentioned problems and is a method for regenerating plastic scrangs that are no longer needed.Resource saving and pollution11)
The purpose of this project was to solve this problem from the standpoint of preventing j, and as mentioned above, cross-linked plastics are made of covalent bonds with a network (q!) and have a q!f property that makes them less likely to gel compared to conventional plastics. I thought of the things I had and used them for exclusive use) (I was captivated by the studies and tests that led to this invention.
Chiru.

The gist of the present invention is to crush plastic scraps without cross-linking. It is used for one night in a recycling method in which it is mixed with old plastic nuts and pelletized at an extrusion temperature of 180° to 200°C.

In the case of this 1tJ, as mentioned above, pelletization is reduced by 4% by mixing with the same value plastic that does not have a 4rili ratio.
This pellet is extremely effective as a cleaning material for cylinders in injection molding machines or extrusion machines where gelation is required in a gel state of J shielding degree. It can also be used as other molding materials (4).

In other words, as mentioned above, in the case of cylindrical, cedar, or extruded molds, it is often necessary to change the color of the resin and the composition of the resin. It is used as a cleaning material with the same value as that of 1, but it is expensive and does not gel easily, so the cleaning effect is reduced and the cleaning effect is reduced. There was a point.

However, if the pellets recycled by the method of the present invention can be used as a cleaning material for molding machines, it will be possible to use rfi Jr'
Due to its gelatinized state, it has an excellent adhesive wiping effect on molding residue in the molding pot, and compared to conventional iC, it was able to achieve a cleaning effect of 5-5 with Shoshya's resin and a shorter working time. In addition, since the discarded rack (made from crushed granules of plastic scraps7)6 is used, it is expected that a large reduction in cost will be achieved.

If you go to the examples of unclaimed inventions, it is the same as in Europe.

Example 1 Crosslinked polyethylene (PE) ASTM D2765
Mix waste material with a gel fraction of 35% with non-crosslinked regular polyethylene (PE) at a ratio of 8:1, and make a 90mm
Extrusion t4't' It was extruded into pellets at 180° to 200°C.

Example 2 14 fJj Ethylene Acid Bisodium (Combined (ETA) AST
MI) 2765 with a gel fraction of 40% was mixed with normal non-crosslinked ethylene-bicopolymer (ETA) at a ratio of 9:1 and heated at 180° to 200° using a ggmrn extruder.
Pelletization was performed at an extrusion temperature of °C.

In the above, the blending ratio of cross-linked plastic and non-cross-linked plastic is arbitrary in the range of 9:1 to 1:9, and when producing pellets, compounding agents such as oxidizing agents and i-rules are used. They can be mixed as appropriate.

The pellets processed by the above-described manufacturing method can also be used as a cleaning material for injection molding or extrusion molding machines, and have remarkable utility as an effective means of pollution prevention (saving resources and lowering material costs).

Application agent Patent attorney Takashi Ishii Procedural amendment (-issued) Showa+5R21-October 28th, 1981 Office Director Wakasugi Aio 3, Leap 1 with the PI who makes i'tli corrections ．． Ministry Patent Applicant 4 Agent Address: 101 I 41 Hikari Building 6, 60 Kanda Renmancho, Chiyoda-ku, Tokyo
The number of inventions to be added by suspension is 7, the subject of amendment is 1, and the scope of claims is amended as follows.

(1) Powder the rack fA plastic scrap.
This is crosslinked and mixed with a thermoplastic of the same type of citron, which is melted at an extrusion temperature of 150° to 280°C, solidified by cooling, and pelletized. (2) The Ij plastic substrate is made of cross-linked polyethylene and tested according to ASTM D2.
→ Sketching method (3) of cross-linked plastic scrap described in Section 1 of Patent No. 11, which has a gel fraction value of 30% or more according to No. 765. Polymerization [(EVA) Plastic scrap recycling method 2 described in item 1 of the patent, which has a gel fraction value of 40% or more according to ASTM D2765, page 8, line 18 of the specification, same as line 5 5th line of the page, 11th line of the same page "180°~200°Cj rxso'~2
80°C”.

Claims (1)

[Claims] h) Crush the <iRun Pujisnax Clamp, mix it with the same heat-deformable plastic 71, and melt it in a bath at an extrusion temperature of 1800 to 200°C. 5. Recycling method of plastic scrap (2) Cross-linked plastic scrap is converted into cross-linked polyethylene according to ASTM D2.
Recycling method of cross-linked plastic scrap according to item 1, item 4 (8) Cross-linked plastic scrap (iii) tl:ff hi coy (combined (EVA) ASTM
The method for recycling plastic skunk tubing according to claim 1, wherein the gel fractionation value by D2765 is 40% or more.