FR2815275A1 - Recycling of plastics materials which are chemically incompatible, comprises reducing them to granules to be mixed in given proportions to give a mixture with a common softening point - Google Patents

Abstract

Recycling of plastics materials of different types, comprises initially shredding the material to pieces in dimensions of about 10 mm. The shredded material is then reduced to granules of about 800 microns. A mixture is formed with the different components in given proportions in a mixing silo, with an additional third component if required.

Description

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La présente invention a pour objet un procédé de recyclage de matières plastiques destiné en particulier, mais non exclusivement au recyclage de matières plastiques incompatibles, c'est-à-dire présentant des caractéristiques physiques et/ou chimiques, en particulier des points VICAT, différents en vue de donner un matériau recyclé homogène. PLASTIC RECYCLING PROCESS

The subject of the present invention is a process for recycling plastics intended in particular, but not exclusively for the recycling of incompatible plastics, that is to say having different physical and / or chemical characteristics, in particular VICAT points, in order to give a homogeneous recycled material.

There are often manufactured parts such as automobile optics resulting from the assembly of incompatible composite materials, comprising for example ABS (Acrylonitrile Butadiene Styrene) or more generally a styrene acrylonitrile (SAN) and PMMA (polymethacrylate methyl), the constituent parts of which are welded together, for example by ultrasound. In the case of credit cards, these result from a multilayer assembly including PVC (Polyvinyl Chloride).

A first object of the invention is to overcome this drawback and to allow the recycling of different materials to give homogeneous recycled composites.

À mélanger selon une proportion déterminée les différentes matières obtenues dans un silo mélangeur avec éventuellement un troisième composant. According to the invention, the process for recycling different plastics is characterized in that it consists in: - First shredding the pieces of plastics to reduce them to a size of the order of 10 mm; - To micronize the material thus obtained to obtain a particle size of the order of 800 microns;

To mix according to a determined proportion the different materials obtained in a mixing silo with possibly a third component.

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Powders of homogeneous composition are thus obtained which can be molded or extruded with a view to a new use of the composite material obtained and, for example of plastic pipes.

Preferably, the shredding is carried out in a shredding device such as that described in EP-A-749783 which has the advantage of requiring little energy.

Powder reduction is carried out in a commercial micronizer which violently projects the particles from the shredding against rotating metal walls.

Homogenization is advantageously carried out in a homogenization silo of the type described in FR-A-2 721 288 comprising a cylindrical tank whose upper part comprises a feed hopper and whose lower part is connected to the upper part by a recirculation duct which allows a vertical slice of mixed materials to be taken from the lower part and to distribute this slice horizontally to the upper part of the tank. And the operation continues until the mixture obtained is perfectly homogeneous.

EXAMPLE.

It is proposed to obtain a plastic mixture from three components, namely: \ - 1/3 ABS.

- 1/3 SAN and derivatives.

- 1/3 PVC.

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The recovered parts are first shredded and crushed, preferably on the production site. They are then calibrated, for example to a diameter of ten millimeters, and any metal inserts are removed by magnetic means.

The mixture thus obtained can then be conveyed to a central processing unit in which it is micronized to 800 microns, for example and introduced into a mixing silo of the type of that mentioned above.

A mixture is thus obtained, the VICAT point of which is 820 and which can be shaped by conventional plastics methods.

It goes without saying that many variants can be made, in particular by substitution of equivalent technical means, without departing from the scope of the invention.

Claims (1)

 10 A process for recycling different plastics, characterized in that it consists in: - First, shredding the pieces of plastics to reduce them to a size of the order of 10mm; - To micronize the material thus obtained to obtain a particle size of the order of 800 microns; - To mix in a determined proportion the different materials obtained in a mixing silo with possibly a third component.  2 mixture obtained by the process according to claim 1, characterized in that it comprises 1/3 of ABS, 1/3

 of SAN, 1/3 of PVC with a VICAT point of 82 C.