PP-RCT Material (New Class of PP-R material – Type 4)
For its pipes, PESTAN uses most advanced material on the market, supplied by Borealis. Plastic pipes made from Polypropylene Random Coopolymer (PP-R) were introduced more than 20 years ago. Since then, they have been used mainly for hot and cold water pipe systems and have significantly contributed to the growth and acceptance of plastic pipes for plumbing and heating systems. Over the time, system components have been gradually improved, more data and testing has been done on material, which lead into developed of PP-RCT (Beta-PPR) resin. Systems made of PP-RCT material can be operated at higher stresses at elevated temperatures.
Pressure tests in accordance with ISO 9080 on pipes manufactured from PP-RCT materials demonstrate a 50 year strength at 158⁰F of 5 MPa, compared to the 3.2 MPa for standard PP-R materials. Offering more than a 50% improvement in long-term strength, Beta-PPR enables designers to select thinner walled pipes and in some situations also smaller diameter pipes can be used. This results in higher pipe hydraulic capacity or the possibility to apply higher pressure than with standard PP-R.
The unique performance of Borealis Beta-PPR is based on three building blocks. On the one hand a multiple-reactor technology is applied to tailor the molecular structure with respect to the molecular weight, molecular weight distribution, co monomer content and distribution. On the other hand Beta-PPR possesses a unique morphology using a special “ß-nucleation” process. In comparison to standard PP-R, which displays only alpha (α) crystals, the crystal structure of Beta-PPR consists to a high degree of ß-crystals and to a minor extent of a-crystals.
The special ß-nucleating leads to a fine crystal structure and a homogeneous crystallite size distribution, attributes that positively affect the mechanical characteristics of a material. A state-of-the-art stabilization and additive package constitute the third building block. This specially designed additive package is based on Boreali’s long-term experience in the field of polyolefin’s for hot water applications and provides superior long-term heat resistance as well as excellent resistance to leaching.