Polypropylene has an excellent track record after more than 30 years of service for non-pressure sewage and drainage applications. The inherent material properties and their development, energy and cost efficiency, pipe design and ease of manufacture and installation have contributed to this success. The traditional cornerstones of the requirements profile such as impact resistance, stiffness and chemical resistance are increasingly being supplemented by demands for purity, sustainability and recyclability. Consequently, the continuous development seen in both material and pipe design has brought additional benefits to pipe producers and end users and is contributing to a more sustainable environment.
The first generation of PP with higher modulus PP was introduced in 1998 and provided a major step forward with an optimized balance of the stiffness-impact properties. A few years later, this product was improved and an E-modulus of 1700 MPa was achieved, representing the first PP-HM to meet the requirements set in the modified EN1852 standard in 2002 (which was adjusted based on the development of this new class of polypropylenes). The journey has continued and recently, the next generation PP for underground drainage and sewage has been introduced. It presents the first and unique 2000 MPa PP-HM from Borealis – BorECO™ BA2000, achieved without the use of fillers, meeting and exceeding the requirements set in the recently - again - modified EN1852.
Pipes are getting larger and larger in diameter, but while plastic pipes are entering the huge market of concrete pipes, the main barrier is still the high price of the raw material. Some authorities still don´t accept and consider the importance of the advantages of a long life time and a sustainable pipe system, or they just don´t want to spend the money for the future of their country. So the question is how producers of plastic pipes made of High Modulus Polypropylene (PP-HM) can deal with this problem.
How can existing “conventional” pipe producers enter these markets with technically better products and very competitive prices? Today large sewage and drainage pipes are mainly produced with standard polyethylene or polypropylenes. Mostly, structured wall pipes are used for these applications according to international standards like:
DIN16961, EN13476, NBR7373,JIS, ASTM F894
Short term E-module (E) of different polyolefin materials (usually they can be used in normal single screw extruders):
To make an easy calculation, we should start with reducing a solid wall thickness by increasing the E-modulus of the material (standard material can also have a higher short time E-modulus).
The main task of pipe systems is to transport a medium in a safe way and without any leakage from one place to another. For polyethylene and polypropylene systems homogenous jointing connections are preferably used, as the sustainability and safety are guaranteed and they are maintenance-free as well.
Flange connections are also a very important jointing method within a pipe system, as they are a detachable connection and thus allow a transition to other pipe materials.
In August 2012 representatives of Borouge and Borealis have visited Krah AG to attend the tests of the Krah Comtruder®-Technology using their high stiffness Polypropylene. The tests were made on a machine sold to the Ukraine and the test runs were made using BorEco BA212E. The customer was very pleased about the results of the extrusion trials.