【德国STC】Why does PPR tube have low temperature brit
Many owners are confused about the causes, manifestations and prevention of low-temperature brittleness of PPR pipes. The following is a detailed introduction:
1、 Why does PPR pipe have low temperature brittleness?
PP-R is a random copolymerized polypropylene, which is obtained by random copolymerization of propylene monomer and a small amount of ethylene monomer under heating, pressure and catalyst. Olefin monomers are randomly distributed in the long chain of propylene. The characteristics of cold brittleness are determined by the content of ethylene and the polymerization mode of ethylene and propylene. In the case of low temperature, especially in the construction process in winter, the flexibility of the pipe is reduced and the rigidity is enhanced at low temperature, showing brittleness.
2、 What are the manifestations of low temperature brittleness of PPR pipes?
1. When the ambient temperature is low, the toughness of PPR pipe decreases and shows brittleness;
2. When the pipe is impacted or pressed by external force, linear cracking will occur, and the cracking starts from the inner pipe and extends to the outer pipe;
3. When the pipe is cracked by the force of a point, the crack will grow rapidly along the axis of the pipe in an instant, which is called rapid crack growth;
4. In winter, pipes are damaged by external forces during transportation, construction site and installation, and brittle and ductile pipe explosion will occur during hot water transmission.
3、 How to avoid low temperature brittle fracture of PPR tube?
1. It is forbidden to throw, fall, roll and drag PPR pipes during handling;
2. The pipes shall be stored in the warehouse and simple shed, and the stacking height shall not exceed.