The heat shrinkable film needs to have high puncture resistance, good shrinkage and corresponding shrinkage stress. During the shrinking process, the film cannot produce holes. Since shrink film is often used outdoors, it is necessary to add UV anti-ultraviolet agent. Including OPS/PE/PVC/POF/PET shrink film.
The production principle of pvc heat shrinkable film The stable state of polymer chain tends to curl state. When the polymer is heated and melted in a highly elastic state, the stretching orientation of the polymer chain is straightened under the action of external force, and after the rapid cooling reaches the glass transition temperature, the orientation state of the polymer chain is frozen.
In recent years, heat shrinkable packaging films have developed rapidly, expanding from a single PVC shrink film to PE, PP, PVDC, PA and other types of shrink films. With the changes in market demand, many new products have emerged in the direction of multi-layered and multi-functional heat shrinkable films. In addition to being widely used in fast food pasta, ceramic products, tea sets, and mechanical parts, heat shrinkable film and vapor phase rust prevention technology are combined in the application of military machinery and hardware tools to replace the method of applying rust prevention oil. Has been widely used, so that guns and ammunition have enhanced the ability to prevent rust, which is of great significance. In addition, co-extruded composite shrink film has also been put into production in Wuxi, Tianjin, Foshan and other places to meet the needs of packaging fresh meat, cheese and other fatty foods.
The cap and the bottle body are two inseparable wholes, so there must be other ways to connect the two. There are usually two types of bottle caps and bottle combination sealing methods. One is the compression seal type with an elastic material between the two. The elasticity of the elastic material and the squeezing force specially driven when tightening can reach a perfect ratio. It is sealed without problems, and the sealing rate is 99.99%. The layout principle is to padded a ring-shaped special elastomer material at the butt of the bottle port and the inner bottom of the bottle cap. It is now widely adopted in packaging with internal pressure, and this situation is almost only required for internal pressure.