IVAR PE-XA

Cross-linked polyethylene is typically obtained from high-density polyethylene (HDPE) through an industrial process called cross-linking.‎ This process, which involves creating strong bonds between polymer chains, transforms polyethylene from a thermoplastic to a thermoset material, significantly improving its resistance to chemicals and mechanical stress.‎ Above all, its resistance to aging (i.‎e.‎, its ability to maintain its properties more stable over time) is improved.‎ From an industrial perspective, crosslinking is achieved through different methods, known by the following names: • Type A crosslinking (chemical method using peroxides) • Type B crosslinking (chemical method using silanes) • Type C crosslinking (physical method using electron bombardment) • Type D crosslinking (chemical method using azo compounds) • In plumbing and heating, type D crosslinking is not used, while the crosslinked polyethylene variants A, B, and C are very common, designated PEXa, PE-Xb, and PE-Xc.‎ Current standards define different minimum crosslinking levels for the different types of crosslinking, primarily for reasons related to production processes, but this does not substantially change the final result, which is still crosslinked polyethylene.‎ Therefore, it makes no sense to speak of "better" or "worse" when comparing crosslinking methods.‎ All plastics have a certain permeability to gases, including oxygen.‎ Even the walls of PE-X pipes can therefore be penetrated by a certain amount of oxygen over time: for this reason, in closed-loop systems such as heating and cooling, they must be equipped with an EVOH (Ethylene Vinyl Alcohol) barrier, capable of drastically reducing the passage of oxygen molecules and thus preventing their diffusion throughout the system.‎ This translates into cleaner circulating water (reducing the formation of algae) and a lower risk of corrosion of the ferrous parts of the system.‎ All PE-X pipes offered by IVAR are therefore equipped with an EVOH oxygen barrier.‎ Further info from manufacturer on IVAR PE-XA IVAR