Carton Factory Eliminates Static Electricity in Packaging and Printing
Release Time：2018-11-29 15:47:04 / From：
Physical elimination is a method of eliminating static electricity without changing the function of materials. For example, "grounding" elimination method is to install anti-static brush in the process. Place the brush body in the winding or unwinding place of paper or plastic rolls, and make the ground end of the anti-static brush reliably grounded, instead of connecting to the equipment or guide rolls. Because the equipment may be grounded badly, the section guide roller is treated by anode and the surface is naturally alumina, while alumina is not conductive.
2. Chemical elimination
Chemical elimination of static electricity, i.e. antistatic agent treatment technology, is a more thorough and perfect antistatic technology, which mainly uses antistatic agent (surfactant) to modify resin or base material by adding (filling) technology or coating technology. However, due to the addition or coating of antistatic agents, the chemical composition of the materials has changed, so the technology is not suitable for paper treatment, but only for the modification of plastic resins.
Especially in food, medicine, cosmetics and chemical products, we should pay attention to safety, hygiene and compatibility with matrix resin, so the technology content is high. Packaging materials with anti-static function not only eliminate all kinds of quality accidents caused by static electricity, but also improve packaging efficiency and ensure sealing strength for customers, so they are recognized by customers.
a: Additive Treatment Technology
This technology (master batch technology) is to prepare antistatic masterbatch by mixing additive antistatic agent with thermoplastic resin at a certain concentration (from several percent to tens of percent) and adding various additives through melting, mixing and granulation. The selection of antistatic agent should pay attention to the compatibility with matrix resin. If the compatibility is too poor, the antistatic particles can not function well, but if the compatibility is too good, the migration speed of antistatic agents to the surface is too slow to form an antistatic water film. In the process of melting, mixing and granulating, it is necessary to keep the processing temperature as low as possible to prevent the decomposition and deterioration of antistatic agents due to poor thermal stability.
Antistatic plastic films are prepared by using antistatic particles. Three-layer (ABC) co-extrusion blow moulding process is often used. Attention should be paid to the proportion of antistatic masterbatch added according to the concentration of its effective substance, and make appropriate adjustments according to the test results, so that its surface resistivity PS can be around 1011. Increasing the amount of antistatic masterbatch not only increases the cost of the product, but also brings adverse effects on the later processing process.
b: Coating treatment technology
Coating antistatic agent treatment technology is to make ionic surfactants into antistatic coatings, which are coated on the surface of plastic film to prevent charge accumulation. The selection of coating antistatic agent should be determined according to the size of the work function of the coated substrate. Plastic materials are liable to be negatively charged if their work function is large, but positively charged if their work function is small. It has been mentioned before that PP and PE are easy to be negatively charged, and cationic surfactants are suitable for coating; PET and PA are easy to be positively charged, and anionic surfactants are suitable for coating. It is required that the surface wetting tension of plastic film be greater than 38dyn/cm, and that the antistatic coatings have good film-forming, friction resistance, chemical corrosion resistance and lasting effect.