Stretch-wrapped film is a kind of packaging method which is produced by mechanical stretching device at room temperature or by forcibly stretching the film by hand. The packaging method is convenient for transportation and storage. It is a kind of packaging which is very popular internationally. form. Imported resin and advanced flow-through film extrusion production process. It has good tensile properties, tear resistance, strong penetration resistance, high transparency, good self-adhesiveness and high retraction rate, tight packaging and no looseness. Can be widely used in chemical raw materials, fertilizers, food, mechanical and electrical products, textile products, and other single-piece or tray packaging and other strapping packaging.
3 methods to check the quality of stretch winding films
There are many stretch winding films on the market, and we can choose high-quality stretch winding films by:
The stretch wrap film is viscous, which allows it to be wrapped around the package to better protect the product. A stretch-wound film to be tested can be taken, stacked vertically twice, pressed by hand, and then peeled off, and the viscosity of the film can be determined according to the ease of uncovering and the degree of damage of the film surface.
2. Tensile rate
The elongation ratio is an important index for judging the quality of the stretch wrap film, and the stretch ratio of the stretch wrap film is generally between 200% and 600%. The stretch-wrapped film to be tested is slightly stretched longitudinally, and the resistance changes linearly according to the force received. If the resistance exceeds this range, the resistance decreases sharply, which can be judged according to this phenomenon. Stretching the stretch ratio of the stretched film) to judge his stretch.
3. Surface gloss
The surface gloss will give people a first impression. The quality of the stretch stretch film raw material is high, and the film surface is fresh and textured. Poor quality or rough surface of the stretched stretch film of the recycled material, feeling no vitality. This is due to the fact that the manufacturer has over-added magnesium powder and calcium carbonate to cover the raw material impurities, resulting in a relatively rigid film surface.