Polypropylene, or PP, is a thermoplastic material belonging to the polyolefin family. It is partially crystalline and it distinguishes itself for a lower density than the other common thermoplastic material. Compared to the latter, the remarkable stiffness of PP ensures a better aesthetic effect and its installation is easier thanks to a lower thermal expansion coefficient. Finally the peculiarities of PP makes it superior to PVC for industrial use.
- High heat resistance
- Excellent chemical resistance
- Not subject to restrictions for food use
- Resistance to high temperatures
- A good resistance to tensile stress
- Non-polar and nonabsorbent material
- Gluing is possible only under certain conditions and after specific surface treatments
- Lack of protection against UV rays: all sections exposed to them must be insulated or protected with absorbent covers.
SOME FIELDS OF APPLICATION
It is highly used in the plastics industry for the production of everyday objects.
PP is the result of polymerised propylene (C3H6) with the addition of a catalyst. It is generally available in three forms for the application in pipelines:
- PP-monomer: it distinguishes itself for its longer life. It is recommended especially for fittings and valves. Safety factor is equivalent to 2.1.
- PP block copolymer (PP-B): it distinguishes itself for its higher capacity at low temperatures. It is recommended especially for pipes and other products which can be subject to particular stresses during their use at low temperatures. Safety factor is equivalent to 1.8.
- PP-random copolymer (PP-R): it finds a favorable application in systems with water at low temperatures.