Filtering technology for recycled thermoplastic materials

There is currently an upward trend in the recycling of plastic materials that pursues to give them a second life. Recycled materials must meet quality criteria required by the specific application for which they are intended. Therefore, it is a priority to establish a series of processes that ensure the elimination of unwanted substances in the recycled material flow.

Among these processes, one of the technologies used for the treatment of thermoplastic materials is filtering. This technique is responsible for separating the unwanted solid content from the molten polymer inside the extruder, using wire-mesh screens that act as a filter pack.

The filtering meshes are made of metallic yarns, mainly steel or titanium, with a specific diameter and mesh geometry depending on the type of waste to be treated. The filter packs are set up under a certain number of screens with different mesh sizes and are placed between the extruder and the die  This technology allows, not only the retention of the impurities of the molten material but also an increase of the mixing energy, providing a greater dispersion and homogenization of the material.

Types of impurities

From the filtering technology, we can separate different types of impurities and/or unwanted particles such as:

• Gels and/or agglomerates
• Metal particles
• Separation of polymers with different melting points
• Paints
• Wood scrap
• Paper

Filtering technology at AIMPLAS

In line with the strategies associated to Circular Economy, AIMPLAS is working in different projects in which filtering technology is being incorporated to develop new compounds from recycled materials, intended to different applications in sectors like packaging, automotive, electronics, agriculture and construction, among others.

AIMPLAS has the equipment needed to carry out the filtering techniques in the compounding and extrusion processes using single and twin-screw extruders respectively for the pelletising of different types of compounds and recycled materials, which will be transformed through injection and extrusion processes at a further stage.

At AIMPLAS, you will find technological support to filter recycled thermoplastic materials. For further information, contact us for a specific request.