Stretch film main protection products, can provide product surface protection, product form is very light, to protect the appearance, so as to achieve the purpose of dust, oil, moisture, waterproof, anti-theft, stretch packaging protective film can be adjusted at the same time tension can make the product tight, soft products, especially in the tobacco industry and textile industry has a unique packaging effect, the following stretch film manufacturers to tell you what are the methods to buy quality stretch film?
First, look at the transparency and measure the tensile strength First of all, from the length of the stretch film direction along with the tear, and then from the direction of the horizontal tear, stretch film with good stretch its impact is strong. Good quality stretch film stretch rate can reach 100%-300%. The cast production method has developed from single-layer to two-layer and three-layer, and now the casting method is mainly used to produce LLDPE stretch film, and the early LLDPE stretch film is blown film. This is because the cast line production has the advantages of uniform thickness and high transparency, which can be applied to the requirements of a high pre-stretch rate. The application area is limited because a single-layer cast can not do single-sided adhesion. The single and double-layer cast is not as wide as the three-layer cast in material selection, and the interest rate of the formula is also high, so it is still more ideal to have a three-layer co-extruded structure. The high-quality stretch film should have high transparency, high longitudinal elongation, high yield point, high transverse tear strength, and good puncture performance.
Second, measure the thickness, see if the film has small particles, and measure the tensile strength Crystal point is a common quality problem of stretch film material, see if there are particles on the surface of the stretch film. Crystal point is the stretch film material surface those small pits, also known as bright spots, it is mainly in the three-layer stretch film material common, the main cause because of the use of silica gel synthesis, silica gel has fluidity, if the stretch film material surface encountered some small particles of extrusion, it will form a crystal point, the best way to avoid crystal point, is to protect the stretch film surface. Stretch film packaging makes the packaging items uniform pressure, to avoid unevenly leading to damaged goods, which is a traditional packaging method (bundling, wrapping, tape, and other packaging can not. Wrapping stretch wrap film acts and retrieves, compact, fixed tape can product as a unit, the whole dispersion is small, even in adverse environment product without any loosening and separation, no sharp edges and sticky to avoid injury.