Early缠绕film was predominantly blow-molded, evolving from single-layer to double-layer and triple-layer. Now, cast film production is the norm due to its advantages of uniform thickness and high transparency, suitable for high-ratio pre-stretching requirements. Single-layer cast film cannot achieve one-side adhesion, thus limiting its application areas. In terms of material selection, single and double-layer cast films have a narrower range than triple-layer cast films, and the formula cost is higher as well. Therefore, a triple-layer co-extrusion structure is more ideal.缠绕film should possess high transparency, high longitudinal elongation, high yield point, high transverse tear strength, and good puncture resistance.