Frequently Asked Questions | Produkty
1. What’s PEX?
1. PEX is the polyethylene, where chains are connected by extra crosswise bonds which has formed in crosslinking process.
Depending on crosslinking method, there are four types of crosslinked polyethylene:
- PEX-a (peroxides crosslinking method),
- PEX-b (silico-methane crosslinking method),
- PEX-c (electron crosslinking method),
- PEX-d (azo compounds crosslinking method).
In comparison with no-crosslinking polyethylene, PEX has following properties:
- higher resistance for creeping in higher temperatures,
- significantly lower sensibility for notch effects,
- lack of strain cracks trends,
- reducing tendency for creeping,
- higher resistance for abrasion,
- lower gas permeability.
2. Why PEX-c?
2. Radiator crosslinking is used for many years. It is a physical method, which advantage is lack of chemical additives. In technological process there aren’t any additional operations connected with removing chemical substances residues. Taking into consideration noxiousness surrounding of production process and product hygienic aspects, it’s necessary to confirm that crosslinked polyethylene pipes fulfilled all modern products requirements.
Pipe extrusion and crosslinking have place in two separate process. Hereof extrusion can be done on standard extrusion moulding lines and pipe dimensions control are much easier.
Polyethylene has additional advantage – ‘shape memory’. Crosslinking degree (65oC -70oC) keeps flexibility and high material resistance simultaneously.
3. What profits result from using aluminum layer?
3. Multilayer pipes PEX/Al combine both plastic and metal features. The aluminum is not only the antidiffusion layer but also fulfilled lot of important functions, which gives extra benefits:
- decreasing pipe thermal linear expansion, which considerably simplify installation,
- increasing mechanical damages resistance.
Easier pipe bending and reclining with simultaneous preserving shape and higher compression resistance.
