Definition And Production Technology Of Winding Film
Dec 29, 2017
Winding film, also known as tensile film, heat shrink film, the earliest in the domestic PVC as the base material, DOA for the plasticizer and the self-adhesive effect of the production of PVC winding film.
Early LLDPE stretch film to blow film For more, from a single layer to two, three layers; the process of producing LLDPE tensile film by flow casting is mainly in the following diagram, which is because the production of the flow line has the advantages of uniformity of thickness and high transparency, which can be applied to the requirement of higher rate pretension. The application field is limited due to the single laminar lag. Single, two-layer flow extension in the selection of materials do not have a wide range of three laminar extension, the formula cost is also high, so it is a three-layer coextrusion structure is more ideal. High-quality tensile film should have the characteristics of higher transparency, high longitudinal elongation, high yield point, high transverse tearing strength and good puncture performance.
Production process conditions: due to the long and narrow flow path, the flow rate is fast, the melt temperature range is generally controlled in the 250℃~280℃, the temperature of the roll cooling roller is controlled in the 20℃~30℃, the winding tension should be low, generally within 10kg, to facilitate the removal of viscous agent, while reducing the finished film stress.