Appearance requirements: transparent winding film (thin and soft transparent sheet), flat, no broken ends, no bubbles, no perforations, no rigid blocks, no rupture. The parent roll is to wind the stretch film produced by the casting machine to form a large parent roll. This is because in the entire production process, we pay attention to many matters in the process, if one of them is not handled properly, it will affect the production quality of the entire product. PE stretch film is a rare film. High-quality stretch film is very transparent, stretch rate is also very good, puncture performance is also very good, now many companies use it to package and transport most of the products to prevent wear. The application industry of stretch film is also relatively wide, and it has applications in logistics, chemicals, plastic materials, building materials, food and other industries. When designing this product, high elastic raw materials are used to ensure that the stretch ratio of the processed film is as high as 1:5, which is twice that of ordinary film. With the increase of the number of C atoms in the comonomer, the branched chain increases, the crystallinity decreases, the "winding" effect of the copolymer increases, the elongation increases, and the breakdown strength and tear strength increase. The die head should be washed clean, colorless impurities, and burnt plastic has fallen into it. If it can be found by the naked eye, it must be removed immediately.