PE is a reasonably soft and tough polymer. Two main types can be identified:

• LDPE (low density PE) and

• HDPE (high density PE)

 
Approximately three-quarters of the manufactured PE is of the LDPE-type. LDPE is considerably less stiff than HDPE.

 
PE ages due to the simultaneous influence of (UV-) light, air and dampness, which can be prevented by mixing in a small quantity of soot.