Which Additives Are Used in The Stretch Film Production Process

1. Biaxial stretching auxiliation
Biaxially oriented materials have always occupied an important position in stretch film packaging, and biaxially oriented polypropylene (BOPP), polyester (BOPET), nylon (BOPA) and other applications are increasingly extensive. Traditional PVC stretch film is widely used in various vegetable and fruit preservation, long-term frozen food packaging, microwave baked food packaging, and conductive stretch film for electronic component packaging.
In addition, the production volume of products such as cast polypropylene (CPP) and cast polyethylene (CPE) is also large. Auxiliary products with the above packaging stretch film materials mainly include antistatic agents, slippery and anti-blocking agents, stiffeners, heat stabilizers, antioxidants and barrier agents.
2. Stretch film antistatic agent
Industrial antistatic agents are mainly single compounds or complexes of some non-ionic and ionic surfactants. According to whether the hydrophilic group in its molecule can be ionized, it is divided into ionic and non-ionic type, and the ionic form is divided into cationic type, anionic type and amphoteric type. The principle of antistatic is to use its hydrophilic base to absorb water vapor in the air on the surface of the plastic, or to form a conductive layer on the surface to reduce the surface resistance value.
Cationic antistatic agent has excellent antistatic performance, but usually poor thermal stability, easy to decompose and cause discoloration under high temperature processing conditions, generally only used in PVC products. The anionic antistatic agent cannot be used for stretch film products because it affects the transparency.
Non-ionic antistatic agent has the characteristics of low toxicity, good thermal stability, and is not easy to cause plastic aging, making it the main internal antistatic agent in packaging materials. The main varieties are fatty acid polyol esters, ethylene oxide adducts of fatty acids, alcohols and amines.
In packaging materials, the determination of the performance of antistatic agents should not only examine their antistatic effects, but also pay attention to its influence on the performance of products. For this reason, the key to the development of antistatic agents focuses on the structural design and compatibility of various surfactants. At present, the development of serial and specialized products is an important development direction of antistatic agents.
3. Anti-blocking agent for stretch film
The faster the processing speed, the easier it is to generate static electricity due to friction, and the easier it is to stick between stretch films (plastic products), which seriously hinders high linear speed extrusion; The better the transparency of the stretch film, the higher the processing and molding temperature, and the easier it is to agglomerate and stick. Therefore, highly effective slippery agents and anti-blocking agents play an exceptionally important role in plastic production and automated packaging.