Vest bag, also known as waistcoat bag, is a kind of common plastic bag. It is named because its shape resembles a vest. The vest bag is simple to make and has a wide range of uses. It has become an indispensable necessity for people in daily life, providing people with great convenience, but at the same time it has caused environmental pollution. For this reason, the country issued a "plastic ban [1]" It is forbidden to produce single-sided vest bags below 2.5 silk, what are the raw materials of plastic vest bags to limit the amount of vest bags
There are many raw materials for plastic vest bags
1. Polyethylene (PE), referred to as PE. It is a polymer organic compound made by addition polymerization of ethylene. Polyethylene is recognized as the best food contact material in the world. Non-toxic, odorless, and odorless, in line with food packaging hygiene standards. Polyethylene film, light and transparent, has the properties of moisture resistance, oxygen resistance, acid resistance, alkali resistance, general air tightness, excellent heat sealability and so on. Known as "the flower of plastic". It is the most important material for plastic packaging printing.
2.PVC--polyvinyl chloride
Polyvinyl chloride is abbreviated as PVC, and its molecular formula is (CH2—CH2) n. It is the most important type of vinyl polymer. It is currently the second largest plastic variety in the world after polyethylene. Domestic production ranks first among plastics. In the printing industry, PVC color calendered films and transparent glazing films are often used to make the packaging and decoration of covers such as books, folders, tickets, etc.
3.Shrinkfilm--shrinkfilm
Shrinkfilm (Shrinkfilm) is a thermoplastic film that is stretched and oriented during the production process and shrinks when it is subjected to hot air treatment or infrared radiation during use. After heat treatment, the film is tightly wrapped on the packaged object, the shrinkage force reaches the maximum during the cooling stage, and can be stored for a long time.
4. LDPE-low density polyethylene
Low-density polyethylene, or LDPE for short, is the most widely used variety in the plastic packaging and printing industry in various countries. The specific gravity is 0.92 ～ 0.93 and can float in water. Low crystallinity (60%), bulk polymerization at a pressure of 1000-3000kg / C㎡, so it is also called high-pressure polyethylene. At 23 ° C, the density is around 0.92. The calendering moldability is poor, and it is processed into a tubular film by the blow molding method. It is suitable for food packaging, fiber products packaging, daily chemical products packaging.
5.HDPE--high density polyethylene
High density polyethylene, referred to as HDPE. The density is 0.941 ~ 0.965g / cubic centimeter. Made with low-pressure polymerization, it is also called low-pressure polyethylene. Milky white, indicating a poor gloss. Processing film can use blow molding method and T die extrusion process. It is heat-resistant and steam-resistant, cold-resistant and freeze-resistant. It has good moisture-proof, gas-proof and insulation properties, and is not easy to be damaged. Very easy to open. Strong paper-like, known as "paper-like plastic film".
What is the raw material of the plastic vest bag
6.BOPP--biaxially oriented polypropylene film
Biaxially stretched polypropylene film, also known as biaxially stretched polypropylene film, English abbreviation code BOPP, is characterized by stretched molecular orientation, mechanical strength, half-fold strength, gas density, moisture barrier is better than ordinary plastic film. Compared with cellophane, the unit price is lower than cellophane. Due to the excellent transparency of this film, the color reproduction after printing is particularly bright and beautiful, and it is an important substrate for plastic composite flexible packaging.