Polyethylene is one of the five major synthetic resins in plastic profile products. It is also the largest importer and second largest consumer of polyethylene in the world. Polyethylene is mainly divided into three categories: high density polyethylene (HDPE), low density polyethylene (LDPE) and linear low density polyethylene (LLDPE). Yimei Plastic Editor talks about the advantages and disadvantages of Low Density Polyethylene (LDPE).
1. Low Density Polyethylene (LDPE):
LDPE is odorless, odorless, non-toxic, and its density is about 0.910-0.940g/cm_. It is synthesized under high pressure of 100-300 MPa using oxygen or organic peroxide as catalyst. It is also called high pressure polyethylene. It is insoluble in water, slightly soluble in hydrocarbons, toluene, etc. It can withstand the corrosion of most acids and alkalis, and has less water absorption. It can still maintain softness and high electrical insulation at low temperature. LDPE is generally referred to as PE pipe in irrigation industry. For example, PE pipe for Huawei irrigation has the advantages of fast installation, non-scaling, easy maintenance and so on. It is widely used in irrigation system.
Advantages: LDPE is the lightest quality product in polyethylene resin. Compared with HDPE, its crystallinity (55%-65%) and softening point (90-100 C) are lower; it has good softness, extensibility, transparency, cold resistance and processability; its chemical stability is better, it can resist acid, alkali and salt aqueous solution; it has good electrical insulation and permeability; water absorption is low; it is easy to burn. It has good elongation, electrical insulation, chemical stability, processability and low temperature resistance (withstand - 70 C).
Disadvantages: The shortcomings are poor mechanical strength, moisture insulation, gas insulation and solvent resistance. Molecular structure is not regular, crystallinity (55% - 65%) is low, and crystallization melting point (108 - 126 C) is also low. Its mechanical strength is lower than HDPE, and its impermeability, heat resistance and anti-sunlight aging are poor. It is easy to decompose and discolor under sunlight or high temperature. So LDPE adds antioxidant and ultraviolet absorbent to improve its shortcomings.
