Polystyren – EPS and GPPS
Polystyrene (PS) is one of the most widespread plastic types and we do all daily use products made of polystyrene. Polystyrene is a thermoplastic, amorphous polymer made from the petrochemical monomeric styrene. It is a crystal clear, rigid and relatively brittle material. Polystyrene has a relatively low resistance to excess oxygen and moisture and has a relatively low melting point. Polystyrene is available in three primary types:
- GPPS – clear glass polystyrene
- HIPS – impact resistant polystyrene
- EPS – expanded polystyrene
At EPS-recycle we work with EPS and GPPS. EPS, also known as flamingo, stands for Expanded Polystyrene and is a product consisting of 98% air. A new pan-European designation “Airpop – engineered air” states that “the material is in fact an intelligent and smart utilization of plastic and air in one and the same material.” The high air content of the material means that it is very light and has an impact-absorbing effect. In addition, the material is airtight, moisture-proof, hygienic and chemically inactive. These properties make the material especially suitable for many uses, including packaging and for insulation of buildings. In the production process of pure EPS, PS granulates are foamed and molded. The only environmental impact in this process is energy consumption (natural gas and electricity). The clean EPS material can easily be reused several times – by melting and converting it to Polystyrene. At EPS recycle, we manufacture recycled GPPS. GPPS offers a wide range of benefits. It is easy to handle and recycle, it is FDA compatible, and it is non-toxic. It has good dimensional stability and is easy to paint and glue. GPPS is of the same quality as PS and can be used to manufacture a wide range of plastic products, from hangers and garden furniture to disposable cups and toys. GPPS also has a low price compared to other plastic materials.
The recycling process – from EPS to GPPS
The challenge of handling EPS for recycling is the low density of the material. This makes it difficult to handle at a recycling site and expensive to transport. To meet this, the material must be compressed to increase the density to over 200 kg / m3. This increases the value and makes the material easier and more safe to transport.
At EPS-recycle the compressed EPS waste is crushed into a grinder and then extruded into GPPS granulates. In the process, the material is heated to 180 degrees. The granulate is then packed in big bags of 900-1000 kg. All activities are carried out on modern machines. Samples and laboratory tests are regularly taken of the supplied EPS material and also of the produced GPPS granules. The tests show melting point, water content and possibly impurities. All tests are carried out in-house on the company’s new laboratory equipment.