Applications of Biodegradable Plastics

Against the global background of plastic restriction and low-carbon development, biodegradable plastics have gradually replaced traditional petroleum-based plastics thanks to their non-toxicity and complete natural degradation after use. Mass industrialized production is realized relying on the PLA foam extrusion line, with its applications mainly divided into three major fields: food packaging, medical supplies and agricultural mulch films.

For food packaging, blended PLA and PBAT materials are widely adopted. Disposable lunch boxes and fresh trays are manufactured by the PLA foam container machine. Modified films feature better air permeability and bacteriostasis to extend the fresh-keeping period of fruits and vegetables. Discarded products can be completely degraded in industrial compost, solving the problem of soil pollution and difficult recovery brought by EPS foam packaging.

Medical scenarios impose strict requirements on material biocompatibility. PLA and PCL can be processed into absorbable surgical sutures, orthopedic fixation plates and 3D printed medical fittings without secondary surgery for implant removal. Modified composite materials can also accelerate human bone repair, serving as core raw materials for trauma repair and tissue engineering.

Traditional PE mulch films will leave residues in soil after use and damage soil texture, while PLA fully biodegradable mulch films can decompose into water and carbon dioxide after farming without manual recovery. Field planting tests prove that plots covered with biodegradable mulch films have higher soil moisture content and crop yield than those covered with ordinary plastic films. Meanwhile, modification with calcium carbonate fillers can effectively lower the manufacturing cost of the complete PLA foam sheet production line.

At present, biodegradable plastics still have drawbacks such as high production cost and uncontrollable degradation rate. The industry generally adopts the matching combination of complete foam equipment and plastic recycling pelletizing lines for coordinated production: foam equipment is used to manufacture finished products on one hand, while production trimmings are recycled and pelletized on the other hand. With continuous upgrades of material modification and supercritical foaming technologies, biodegradable plastics will replace traditional plastics in more application scenarios.