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Polyethylene (PE)



PE is made up from Ethylene monomers. PE is divided into different class according to their density.
Different types of PE are as below:
(Polymers)                   (Density)
LDPE               0.910 -0.940 (g/cc)
LLDPE             0.915 -0.925 (g/cc)
MDPE              0.926 -0.940 (g/cc)
HDPE               0.941 -0.959 (g/cc)
VLDPE             0.880 -0.915 (g/cc)
UHMWPE        0.930 -0.935 (g/cc)
Properties of PE:
√ Very low cost
√  Excellent chemical resistance
√  Very good processability.
√  High impact strength at low temperature.
√ Excellent electrical insulating properties .
√ Very low water absorption
√ Can be transparent in thin film form .
Limitations of PE:
√ Low strength, stiffness and maximum service temperature .
√ Highly flammable .
√ High-frequency welding and joining impossible .
√ Poor abrasion resistance.
Processing of PE:
• For Injection Molding Process:
√ Melt temperature: 160-260°C.
√ Post mold shrinkage lies between 1.5
and 3.5 %.

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