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Differences between Traditional and Co-injection Moulding

Traditional molding is the injection transformation technique for the production of items with small to medium thicknesses. The process starts with the insertion of virgin material through the injection metering zone into the machine, which once melted, is injected into the mold. The machine has a single plasticizing metering zone that brings the plastic into the melt and injects it into the mold. This is followed by a cooling time and subsequent extraction of the piece by an automated arm. On average, articles with a maximum thickness of 6/8 mm are produced.

Co-injection molding differs from the previous process in that the material injection metering zone become two and no longer one.The two materials are divided into the body (core) and the skin of the article. This innovative process allows to melt together recycled materials, obtaining an aesthetic of the product equal to the traditional molding with virgin material. In the process, the recycled material forms the core of the article, which is covered by the virgin material that makes up the skin. Moreover, in most cases the core is added with expanding granules to avoid the deformation of the article.

The first great advantage of this technique is the reduction of CO2 emissions, obtaining articles with recycled material of great aesthetics, the second is the possibility to have larger thicknesses of the article reducing the risk of deformation.

In many cases, in the traditional transformation process, some points of the article are subjected to too much pressure during the process, thus causing possible deformation of the final article. However, in Co-injection since the articles are thicker, they are able to withstand higher pressures without generating any type of distortion. The articles obtained have thicknesses from 15 to 40 mm.

The Restylon technology allows the realization of Co-injection products with the use of second life material, producing high quality articles without deformation.