Views:1 Author:Site Editor Publish Time: 2020-06-04 Origin:Site
PE tarpaulin is a tarpaulin made of polyethylene as a chemical raw material. For the explanation of PE, please see below:
PE: Polyethylene PE resin is non-toxic and odorless white granules or powder, milky white in appearance, feels like wax; flammable, oxygen index is only 17.4%, low smoke and dripping when burning, the flame is yellow and blue, there is Paraffin odor; low water absorption (polyethylene PE polyethylene PE molecule contains a small amount of double bonds and ether groups, so the weather resistance of PE is not good, sun and rain will cause aging, need to add antioxidants, light stabilizers to improve .
The thermal stability of polyethylene PE in inert gas is very good, the decomposition temperature can reach more than 300 ℃; but when the temperature exceeds 50 ℃ under heating, thermal oxygen will cause degradation reaction, so it is necessary to add antioxidants to improve, such as The main antioxidant 1010 and the auxiliary antioxidant 168; the heat resistance of PE in air is not good, and it improves with the increase of molecular weight and crystallinity; but the low temperature resistance of PE is very good, its low temperature embrittlement temperature is Below -50℃, and with the increase of molecular weight, the lowest can reach -140℃; the thermal conductivity of PE is high, HDPE>LLDPE>LDPE; the linear expansion coefficient of PE is large, which is the largest among plastic varieties, and the highest (20~24)×10 -5 -5 K -1 -1, LDPE>LLDPE>HDPE.
⒈ Low-density polyethylene LLDPE Low-density polyethylene LLDPE: Low-density polyethylene molecular chain has long and short branches, low crystallinity, molecular weight is generally 50,000 to 500,000, a milky white translucent wax-like solid resin, no Poisonous, low softening point, good flexibility, impact resistance, low temperature resistance, can work at -60 ℃ ~ -80 ℃, excellent electrical insulation. LDPE has poor mechanical strength, low heat resistance, poor resistance to environmental stress cracking, adhesion, and printability. Surface treatment is required to improve its performance.
2. LDPE has very low water absorption, almost no water absorption, and excellent chemical stability, such as acid, alkali, salt, and organic solvents. High permeability to carbon dioxide and organic odor, but poor permeability to water vapor and air. Easy to burn, burning with paraffin smell, easy to age and degrade under the action of sunlight and heat and change color.
⒊ High-density polyethylene HDPE: High-density polyethylene HDPE: Wax-like translucent waxy solid, HDPE branching degree is minimal, the molecules can be closely packed, so the density is high and the crystallinity is high. HDPE has high temperature resistance, 1653 oil resistance, steam permeability resistance and environmental stress crack resistance, electrical insulation, impact resistance and cold resistance are very good. HDPE is superior to PP in strength and aging performance, and the working temperature is higher than PVC and LDPE. HDPE has extremely low water absorption, non-toxicity, excellent chemical stability, and low permeability of the film to water vapor and air.