The plastic bag materials we commonly use are as follows:
Polyethylene (PE), referred to as PE. It is a high molecular organic compound obtained by addition polymerization of ethylene. Polyethylene is recognized as the best material for food contact in the world. Non-toxic, odorless, odorless, in line with food packaging hygiene standards. Polyethylene film, light and transparent, with moisture, oxygen, acid, alkali, air tightness, heat sealing and other properties. Known as the "plastic flower" rdquo; It is the most important and most important material for plastic packaging printing.
LDPE--low density polyethylene
Low-density polyethylene, referred to as LDPE, is the largest variety in the plastic packaging and printing industry in various countries. The specific gravity is 0.92~0.93, which can float in water. Low crystallinity (60%), bulk polymerization at a pressure of 1000-3000kg/cm2, so it is also called high-pressure polyethylene. At 23 degrees Celsius, the density is around 0.92. The calendering formability is poor, and it is suitable for processing into a tubular film by a blow molding method. Applicable to food packaging, fiber packaging, and daily chemical packaging.
HDPE--high density polyethylene
High density polyethylene, referred to as HDPE. The density is from 0.941 to 0.965 g/cm 3 . It is made of low pressure polymerization, so it is also called low pressure polyethylene. It is milky white, indicating poor gloss. The processed film can be blow molded and T-die extruded. Heat-resistant and resistant to cooking, cold and freeze-resistant, moisture-proof, gas-proof, good insulation performance, and not easy to break. The most common are supermarket shopping bags and plastic vest bags.
PVC--polyvinyl chloride
Polyvinyl chloride is abbreviated as PVC and its molecular formula is (CH—CH)n. It is the most important type of vinyl polymer and is the second largest plastics in the world after polyethylene. Domestic production is the highest in plastics. In the printing industry, polyvinyl chloride color calendered film and transparent glazing film are often used to make packaging and decoration of books, folders, tickets and the like.
Shrinkfilm--shrink film
Shrink film is a thermoplastic film that is stretched and oriented during the production process and shrinks during hot air treatment or infrared irradiation during use. After heat treatment, the film is tightly wrapped around the package, and the shrinkage force reaches a maximum during the cooling phase and can be stored for a long time.
BOPP--biaxially oriented polypropylene film
Biaxially stretched polypropylene film, also known as biaxially oriented polypropylene film, the English abbreviation code BOPP, which is characterized by tensile molecular orientation, mechanical strength, folded strength, gas density, moisture barrier resistance is superior to ordinary plastic film. The unit price is lower than that of cellophane compared to cellophane. Because of the excellent transparency of the film, the color reproduction after printing is particularly bright and beautiful, and is an important substrate for plastic composite flexible packaging.
