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Polypropylene (PP) has a higher heat resistance compared to PE and is therefore a favorable standard material for use at higher temperatures.
Furthermore, it is characterized by high mechanical strength, good chemical resistance and physiological harmlessness.
Our product range includes various types of polymers: the homopolymers (PP-H) composed exclusively of propylene molecules and the two different copolymers in which blocks (polypropylene block copolymer, PP-B) or randomly distributed (polypropylene random copolymer, PP- R) ethylene monomers. Our pipes are made of PP-H and our PP-R moldings. Both types are highly heat stabilized and ideally suited for the production of pressurized piping systems. The different types of propylene can be combined with all common welding processes.
The impact strength is temperature-dependent and decreases with increasing temperature to or with falling temperature. PP-R has a better impact strength compared to PP-H.
In contrast to energetic radiation, polypropylene is generally not permanently stable. On exposure to energetic rays on polypropylene, a temporary increase in strength can occur due to crosslinking of the molecular structure. In the case of permanent radiation exposure, however, a break in the molecular chains and thus a damage to the material leads to a considerable reduction in strength. This behavior must be taken into account by a reduction factor, which must be determined experimentally.
Pipes made of gray polypropylene are not UV-stabilized and therefore have to be protected accordingly. If effective protection is not possible, outdoor use is still possible in accordance with DVS 2210-1. Under UV radiation, an oxide layer is formed on the surface of the tube, which can be absorbed by a computational wall thickness impact. This wall thickness impact should be at least 2 mm according to DVS. The duration of use is limited to 10 years.
Polypropylene corresponds in its composition to relevant food regulations (according to BGA and KTW guidelines). Furthermore, the PP pipes and fittings are tested and approved for drinking water suitability.
In principle, PP is considered to be resistant to a variety of acids and alkalis. Alkaline sulfuric acid, phosphoric acid, hydrochloric acid are only an excerpt of which PP is resistant. Compared to hydrocarbons, however, PP is only conditionally stable as it can lead to a swelling> 3%. As a result, PP is less suitable for gasoline. The same also applies to free chlorine and ozone. Due to its high temperature stability, PP is ideal for use in pickling plants, the chemical industry as well as highly aggressive sewage water. The chemical resistance, however, must always be considered in conjunction with the operating temperature, the operating pressure and any external stresses, as these may result in limitations. The chemical resistance list is the first reference. Specific applications can be clarified with our technical department.
