PVC (Polyvinyl Chloride) PVC is currently the most used material for plastic pipes. Since PVC contains chloride, a smaller quantity of ethylene is needed to produce the material, which means that PVC is relatively cheaper to manufacture than PB and PP. PVC pipes are used for all types of pressure and gravity pipes. PVC pipes are also used as conduits for electric and telecommunications cables, for drainage pipes and for industrial process pipelines where the temperature does not exceed +45°C.
PE (Polyethylene) PE pipes were previously designated PEL, PEM or PEH pipes, where the last letter refers to the density of the material: L = Low, M = Medium, H =High. However, this method of classification does not provide any information on the long-term strength of the polyethylene material. Therefore, in the on-going European standardisation work (CEN), a new method of classification has been adopted that is based on the strength of the material: "Minimum Required Strength", abbreviated to MRS. This indicates the stress the pipe material can endure without breakage over a period of at least 50 years. PE 100 piping, according to the previous classification system is equivalent, with respect to density, to PEH pipes while PE 80 pipes covers both PEM and PEH pipes according to the earlier designations. PEL pipes in accordance with the old classification system is now classed as PE 40 pipes. PE pipes have the same application area as that given for PVC pipes. Furthermore, PE pipes are also used for gas pipes and submarine pipes.
PP (Polypropylene) PP pipes are available as homopolymers or copolymers PP-PE (copolymer: a small addition of ethylene during polymeisation has been made to make the material tougher). PP pipes are used as indoor wastewater pipes, buried wastewater pipes, tap water pipes and for industrial process pipelines.
PVDF (Polyvinylidene Fluoride) PVDF is a fluorine plastic that is mainly used for industrial process piping where very high chemical resistance is required and also high temperatures are involved. PVDF shows an excellent behavior, both mechanically and physically, it is chemically inert toward most acids, organic aliphatic and aromatic compounds, solvents, oxidants, halogens and alcohol. PVDF is obtained through the polymerization of vinylidene fluoride, a highly crystalline structure characterized by the high-energy bond existing between Fluorine and Carbon atoms, in fact the strongest of all single bonds involving Carbon.
EVOH (Polymer Ethylene Vinyl Alcohol) EVOH is the ethylene vinyl alcohol copolymer resin introduce in the early 70's. Thanks to the sound balance of the copolymerization ratio of ethylene to vinyl alcohol and the carefully selected degree of polymerization, EVOH is characterized by excellent processability and outstanding barrier properties. The gas barrier properties of EVOH are superior to those typical of any other conventional polymer and its resistance to hydrocarbons and organic solvents is outstanding.