PET film recycling technology

With the continuous enhancement of environmental awareness, the recycling technology of PET (polyethylene terephthalate) film has received extensive attention and development. PET film is widely used in food packaging, beverage bottles, cosmetic containers and other fields due to its excellent performance. However, a large amount of PET waste also brings environmental pressure. Therefore, it is of great significance to develop efficient and economical PET film recycling technology.

Overview of recycling technology

PET film recycling technology is mainly divided into two categories: physical recycling and chemical recycling. Physical recycling refers to the reprocessing of waste PET materials into new products by mechanical means, while chemical recycling is the decomposition of PET into monomers or other useful substances through chemical reactions, and then resynthesizing new PET materials.

Physical recycling

Physical recycling is the most common method for recycling PET film. Its basic process includes collection, classification, cleaning, crushing, melting and re-granulation. The advantages of this method are simple process and low cost, but the quality and performance of the recycled products may be affected to a certain extent.

Collection and classification

Collection and classification are the first step in the recycling process. Waste PET film needs to be strictly classified to ensure the purity of the recycled material. This step is critical to ensure the quality of the final recycled product.

Cleaning

Cleaning is a key step in removing dirt and impurities from the surface of PET film. Common cleaning methods include mechanical cleaning and chemical cleaning. Mechanical cleaning removes surface dirt by friction, vibration, etc., while chemical cleaning uses solvents or detergents to clean the material.

Crushing and Melt Regranulation

The cleaned PET film needs to be crushed into small particles or fragments. These fragments are then melted and regranulated to form new PET particles for subsequent processing.

Chemical Recycling

Chemical recycling is the decomposition of waste PET materials into monomers or other useful substances through chemical reactions, and then resynthesize new PET materials. This method can produce recycled materials with comparable performance to virgin materials, but the process is complex and the cost is high.

Methanol Alcoholysis

Methanol alcoholysis is a common method of chemical recycling. PET is decomposed into dimethyl terephthalate (DMT) and ethylene glycol (EG) by the reaction of methanol with PET. These monomers can be repolymerized to form new PET materials.

Hydrolysis

Hydrolysis is another chemical recycling method. PET is decomposed into terephthalic acid (TPA) and ethylene glycol (EG) by the reaction of water with PET. These monomers can also be repolymerized to generate new PET materials.

Ethylene glycol alcoholysis

Ethylene glycol alcoholysis is the reaction of ethylene glycol with PET to decompose PET into low molecular weight ethylene terephthalate (BHET) intermediates. These intermediates can be further processed to generate new PET materials.

Application Examples

Efficient Extrusion Devices and Filtration Technology

Combining efficient extrusion devices with innovative filtration technology, PET film containing a high proportion of recycled materials can be economically produced. More and more film manufacturers are using recycled PET bottle flakes instead of pure PET resin raw materials, thereby significantly reducing production costs. This technology not only improves resource utilization, but also reduces environmental pollution.

System Layout and Equipment

In order to achieve efficient recycling of PET film, some companies have developed new system layouts and equipment. For example, Brückner Formtec GmbH (BFT) and Kreyenborg GmbH have jointly developed a system that can process PET virgin material (PET-A) and recycled material (PET-R) into high-performance cast film products. This system combines BFT's competitiveness in the field of PET-A cast film lines and Kreyenborg's expertise in melt control and filtration systems for PET-R cast film lines.

Conclusion

PET film recycling technology is of great significance in environmental protection and resource conservation. Through physical and chemical recycling methods, waste PET materials can be reprocessed into new products, reducing environmental pollution and achieving sustainable development. With the continuous advancement of technology, the recycling efficiency of PET film will be further improved, bringing greater economic and environmental benefits to society.