In the early days, LLDPE stretch film was mostly blown film, which developed from a single layer to two layers and three layers. The casting method is mainly used to produce LLDPE stretch film, because the cast line production has the advantages of uniform thickness and high transparency, which can be applied to the requirements of high magnification pre-stretching. Since single-layer casting cannot be adhered on one side, the application field is limited. Single-layer and double-layer casting are not as wide as three-layer casting in material selection, and the formula cost is also high, so the structure of three-layer co-extrusion is more ideal. High-quality stretch film should have the characteristics of high transparency, high longitudinal elongation, high yield point, high transverse tear strength, and good puncture performance.
