The Difference of HDPE LDPE LLDPE

HDPE

HDPE is non-toxic, odorless and odorless. Its density is 0.940-0.976g/cm3. It is a product of polymerization under low pressure catalyzed by Ziegler catalyst, so HDPE is also called low pressure polyethylene.

(1) advantages

HDPE is a kind of thermoplastic resin with high crystallinity and non-polarity formed by copolymerization of ethylene. The original HDPE is milky white in appearance and translucent in slight section. It has excellent resistance to most domestic and industrial chemicals. It can resist the corrosion and dissolution of strong oxidants (concentrated nitric acid), acids, alkali salts and organic solvents (carbon tetrachloride). The polymer is non-hygroscopic and has good waterproof vapor property. It can be used for moisture-proof and seepage-proof purposes.

LDPE

LDPE is non-toxic, odorless and odorless. Its density is 0.910-0.940g/cm3. It is synthesized under high pressure of 100-300 MPa using oxygen or organic peroxide as catalyst. It is also called high-pressure polyethylene.

(1) advantages

Low density polyethylene (LDPE) is the lightest quality polyethylene resin. Compared with high density polyethylene, 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 (withstanding - 70 C).

LLDPE (Linear Low Density Polyethylene)

LLDPE is nontoxic, odorless and odorless. Its density ranges from 0.915 to 0.935 g/cm3. It is a copolymer of ethylene and a small amount of high-grade alpha-olefins (e.g. butene-1, hexene-1, octene-1, tetramethylpentene-1, etc.) under the action of catalyst. The molecular structure of conventional LLDPE is characterized by its linear main chain, with only a small or no long branched chain, but contains some short branched chains. 。 The crystallinity of polymers is higher without long branched chains.

LLDPE Resin Products

Compared with LDPE, LLDPE has the advantages of high strength, good toughness, strong rigidity, heat resistance and cold resistance. It also has good environmental stress cracking resistance, tear resistance, acid resistance, alkali resistance and organic solvent resistance.

LDPE is more soft than HDPE