Stretch film production has the characteristics of simple operation, wide application range, good airtightness, high transparency, low cost, high grade, etc., and is suitable for the packaging of small and medium batch products. However, there is another kind of stretch film that has the benefit of being recyclable-black stretch film.
Black stretch film and general stretch film are extruded through an extruder. It has high tensile strength, puncture resistance and impact resistance. It has outstanding retraction memory and self-adhesiveness. By choosing different resins , Can make the goods tightly wrapped into a whole to avoid pollution and damage during transportation.
In addition, when the black stretched film is heated to the glass transition temperature, it can be ensured that it is relatively stable at room temperature. The heat generation is shortened, and the direction of the heat shortening is in the same direction, and the heat shortening rate can reach more than 70%. Thermally shortened polyester films are often used in convenience foods, beverage stores, electronic appliances, and metal products. In particular, shortening labels is the most important application field. Due to the rapid development of beverage bottles, beverage bottles such as cola, sprite, and various juices all require stretch films to be matched with heat-sealing labels, which are also classified as polyester, environmentally friendly materials, and easy to be recycled for reuse.
It can be said that black stretch film has the following advantages compared with general colorless stretch film:
First, it is conducive to packaging valuables and privacy items, and the packaging can be well concealed during storage and transportation;
Second, the use of universal recycling equipment can reduce environmental pollution, recycle black stretched film, and save packaging costs;
Third, because the thickness of the pre-stretched black stretched film is significantly thinner, the total transportation volume during transportation is reduced, thereby reducing transportation energy consumption and transportation vehicle exhaust emissions, or indirectly or directly reducing the pollution to the atmospheric environment .
Fourth, because the black stretched film is processed by pre-stretching technology, it is easy to use and has high work efficiency. It can be said that the length of each roll of black stretch film is more than twice the length of each roll of ordinary stretch film under the same weight, which can reduce the frequency of film roll replacement during packaging.
However, correspondingly, compared with the advantages brought by the black stretch film itself, its production conditions are also quite harsh. The melting point of the black stretched film is 178°C, and the maximum crystallization temperature is 141°C. The stretching process conditions are mainly related to temperature. To obtain high-performance and high-quality black stretched films, strict control of the production process conditions is required.