Physical Recycling Of PET Plastic Bottles

The physical recycling method for PET plastic bottles is relatively simple, mainly involves drying and granulating the cleaned PET plastic bottle waste. The physical processing method of PET plastic bottles is closely related to the sorting process. There are two main methods of physical recovery: one is to cut waste PET plastic bottles into pieces, separate HDPE, aluminum, paper, and adhesive from PET, and then wash, dry, and granulate PET fragments; The second is to first separate the non PET bottle caps, seat bottoms, labels, and other impurities on the waste PET plastic bottles using mechanical methods, and then wash, crush, and granulate them. Regenerated PET must not contain PVC impurities, otherwise it will affect the color of the PET. When the amount of PVC mixed is small, it can be separated manually on the conveyor belt, that is, under the action of torsion, PVC and PET plastic bottles produce different melting points in the stressed part. The broken PET and PVC fragments are passed through the conveyor belt equipped with a heater and temperature control, and PVC is melted and adhered to the conveyor belt, which can be separated from PET. The label on the beverage bottle can be removed by a combination of a blower and a cyclone separator after the bottle is broken. An extraction tower separation device can also be used to separate the broken PET fragments, which are vertically added from the top of the separation tower. The fragments form a countercurrent with the upward airflow. By utilizing the difference in the specific gravity of PET and tag fragments, the tags are removed and PET comes out from the bottom of the separator. To ensure the efficiency of tag separation, more than two sets of separation devices can be used in production. The washing of PET fragments is very important. Washing often uses hot water at 80-100 ℃ to soften or dissolve EVA adhesive or other types of adhesive used for labels and bases. To prevent the adhesive from adhering to PET fragments, additives such as alkali, emulsifier, or other specialized chemical agents need to be added to the water. The formula composition and content of cleaning solution are generally determined by the factory based on the source and bonding characteristics of waste bottles. The cleaning solution can filter out impurities and reheat before recycling. Washing can be carried out in a special cleaning tank equipped with a stirrer. To ensure the cleaning effect, a two-stage washing process can be used for washing. PET fragments are usually dehydrated by a centrifugal dryer to reduce the moisture content to 2%, and then dried by a belt or tube dryer to reduce the moisture content to 0.5%. The high-quality PET plastic bottle recycling system successfully developed by German company Krones has an annual processing capacity of 15000 tons of PET beverage bottles. The processed PET raw materials can be directly made into other PET containers, greatly reducing production costs. The PET plastic bottle recycling system utilizes chemical coating removal technology, using caustic soda as a chemical coating remover to remove pollutants adhering to the surface of PET plastic bottles, and can achieve the recycling of any type of PET plastic bottle. The recycled products processed by this technology can not only be directly mixed to produce bottle preforms, but also meet the requirements of purity and quality due to the low content of acetaldehyde and yellow pigment. They are particularly suitable for packaging products in the food and beverage industry, with a cost lower than general new materials by 20% -30%.