The Physical recycling of PET plastic bottles

- Apr 25, 2018-

The physical recycling method of PET plastic bottles is relatively simple, mainly to dry and granulate the washed PET plastic bottle waste. The physical treatment of PET plastic bottles is closely linked to the sorting process. There are two kinds of physical recycling methods. First, shredded PET bottles are cut into pieces. HDPE, aluminum, paper and adhesives are separated from PET. The PET chips are washed, dried, and pelletized. Non-PET caps, seat bottoms, labels, and other impurities on waste PET plastic bottles are mechanically separated, washed, broken, and pelletized. Recycled PET must not contain PVC impurities, otherwise it will affect the color of PET. When the amount of PVC mixed is small, it can be manually separated on the conveyor belt. That is, when the torque is applied, PVC and PET plastic bottles have different melting points in the force part, and the broken PET and PVC pieces pass through the heater and temperature. In the controlled conveyor belt, the PVC is melted and adhered to the conveyor belt so that it can be separated from the PET. The label on the beverage bottle can be removed after the bottle is crushed with a blower and cyclone separator. It can also be separated by suction tower separation device. The broken PET pieces are added vertically from the top of the separation tower. Fragments and updrafts form a counter flow. The difference in specific gravity between PET and the label is used. The label is pumped and the PET comes out from the bottom of the separator. Label separation efficiency can be used in the production of more than two sets of separation devices. The washing of PET chips is very important. Washing often uses 80-100°C hot water to soften or dissolve EVA adhesives or other types of adhesives used to attach labels and pedestals. In order to prevent the detached adhesives from adhering PET chips, additives such as alkali must be added to the water. , Emulsifiers or other special chemicals. The cleaning solution is generally determined by the factory based on the source and adhesive properties of the waste bottle. The composition and content of the cleaning solution can be filtered and the impurities can be filtered and reused. The cleaning can be performed in a special cleaning tank equipped with a stirrer. The effect of cleaning, washing can be used two-stage washing process. PET chips usually use centrifugal dehydrator to reduce the moisture content of the chips to 2%, and then dried by a belt or tube dryer to reduce the moisture content to 0.5%. The Krones company successfully developed a high-quality PET plastic bottle recycling system, which can process 15,000 tons of PET beverage bottles each year. The processed PET raw materials can be directly made into other PET containers, and the production cost is greatly reduced. The PET plastic bottle recycling system utilizes a chemical coating removal technology to remove caustic soda from the surfaces of PET plastic bottles by using caustic soda as a chemical coating remover. This allows PET bottles of any kind to be recycled. The recycled products processed by this technology can not only be directly mixed to make preforms. At the same time, recycled products can meet the purity and quality requirements due to the low content of acetaldehyde and yellow pigments, and are particularly suitable for products in the food and beverage industry. Packaging costs 20%-30% lower than new materials.