Low density polyethylene films are generally made using two processes: blow molding and tape casting. The thickness of cast polyethylene film is uniform, but due to its high price and low cost, it is most widely used. Low density polyethylene film is a semi transparent, glossy, and soft film with excellent chemical stability, heat sealing, water resistance, and moisture resistance. It is resistant to freezing and can be boiled in water. Its main drawback is its poor barrier to oxygen, which is commonly used as the inner film of composite soft packaging materials. It is also the most widely used and widely used plastic packaging film, accounting for over 40% of the plastic packaging film consumption.
Due to the absence of polar groups in polyethylene molecules, high crystallinity, and low surface free energy, the printing performance of the film is poor, and its adhesion to ink and adhesive is poor. Therefore, surface treatment is required before printing and lamination.
