PE 100-RC materials have become an essential and well established sub-family of PE 100 compounds. They have a higher stress crack resistance and hence less risk of failure due to damage during installation or due to point loads after installation. This in turn has facilitated the greater use of trenchless technology installation methods, which have a reduced environmental impact.
Polyethylene molecules are branched, with the degree of branching in the molecular chains and the length of side chains having a considerable effect on the properties of polyethylene. When molten polyethylene cools, it crystallises. Different degrees of crystallisation produce different densities, due to the crystallisation regions having a higher density than amorphous regions. The degree of crystallinity ranges between 35% and 80% according to polyethylene grade. High density polyethylene (HDPE) attains a 60-80% degree of crystallinity at a density of 0.940 g/cm3 to 0.965 g/cm3; medium density polyethylene (MDPE) attains a 50-60% degree of crystallinity at a density of 0.930 g/cm3.
In order to check the stress crack resistance of the material it requires samples to be tested in a Full Notch Creep Test (FNCT) and a Point Load Test (PLT) at 4MPa in a 2% Arkopal N-100 solution at 80°C for 8,760 hours (N.B. Arkopal N-100 is a liquid surfactant that accelerates stress cracking in PE materials).
The properties of polyethylene are primarily determined by density, molar mass and molar mass distribution.
With increasing density (higher crystallinity), the following properties are increased: tensile strength; stiffness; hardness; solvent resistance, while the permeability to gases and vapours is reduced. On the other hand impact strength, transparency and stress cracking resistance decrease with increasing density.
PE 100-RC boasts the following properties:
Excellent resistance to a wide range of chemical applications, on all surfaces, internal and external
A specified design life with unlimited fill and empty cycles
Highly ductile, flexible and lightweight
pH resistance across the full range
Extremely low coefficient of thermal conductivity
Suitable for outdoor use due to its UV stability
Maintained integrity at very low temperatures
Compliant with EU Directive 2002/72/EU (Food grade Plastic Materials) and WRAS approve
