Plastic buffer packaging materials are widely used for various precision instruments, household appliances, glass products, ceramics, crafts, and valuable items. They serve as inner packaging materials to create cushioning pads, bags, and board boxes. The main types of plastic buffer packaging materials include foam plastic buffer materials and air cushion buffer materials. The most commonly used foam plastic buffer materials are expandable polystyrene (EPS), expandable polyethylene (EPE), and expanded polypropylene (EPP).
Expandable Polystyrene (EPS)
EPS buffer materials are made from the suspension polymerization of styrene with added foaming agents. EPS has excellent shock absorption, high compressive strength, good moisture resistance, and is resistant to grease. It is easy to process, affordable, and widely used. However, EPS deforms easily under compression, has poor reusability, can break and produce dust, occupies significant volume, and is non-degradable and difficult to recycle. Moreover, incineration of EPS releases harmful gases, contributing to environmental concerns when used on a large scale.
Expandable Polyethylene (EPE)
Commonly known as pearl cotton, EPE is a closed-cell thermoplastic foam material that offers high cushioning, good shock absorption, and excellent recovery properties. EPE is typically produced through solution foaming or mold foaming, processes that are complex and time-consuming. This material is recyclable and environmentally friendly but relatively expensive.
Expanded Polypropylene (EPP)
EPP materials are generally made by loading EPP pellets into a pressure vessel where they are expanded and bonded using steam, with the help of compressed air guns and EPP molding machines. EPP features low density, high elasticity, excellent shock and compression resistance, and resistance to oils, acids, alkalis, and various chemical solvents. EPP maintains its performance even under 100% recycling conditions, making it an environmentally friendly plastic. EPP is widely used in the automotive industry and is essential for packaging in the import-export sector.
