2018 Las-Vegas : Determination of the slow crack growth resistance of PA12 pipe grades
Author(s) : Mario Messiha, Andreas Frank, Isabelle J. Berger, Jan Heimink, Hermann van Laak, Florian Arbeiter, Gerald Pinter
Since the last decade polyamide 12 (PA12) has been successfully introduced as material for SDR 11 gas piping systems up to 18 bar, representing itself as an attractive alternative to steel pipes for high-pressure applications. Practical experience has confirmed that beside the higher strength, PA12 pipe grades also...
2018 Las-Vegas : Investigation of the failure behavior of polyethylene electrofusion sockets
Author(s) : Isabelle J. Berger, Andreas Frank, Gerald Pinter, David Nitsche, Dirk Petry
Electrofusion (EF) sockets constitute a well-established and practically proven technology for the joining of polyethylene (PE) pressure pipes. As for the pipes, the potential lifetime of such welding connections is beside other properties also depending on the resistance against slow crack growth (SCG). The current...
2018 Las-Vegas : Multilayer polymer pipes - Possible utilization of recycled material
Author(s) : Pavel Hutar, Jan Poduska, Pavol Dlhy, Andreas Frank, Jaroslav Kucera, Jiri Sadilek, Gerald Pinter, Lubos Nahlik
This paper investigates possible use of recycled material as a part of a multilayer polyethylene pressure pipe system. Crack propagation in different configurations is simulated. Lifetimes of pipes containing recycled material are calculated. Results are compared with lifetimes of pipes made of virgin...
2018 Las-Vegas : New en standard for infiltration units
Author(s) : Peter Verlaan
Ten years ago, The European Plastic Pipes and Fittings Association (TEPPFA) has taken the initiative to prepare a draft 'Standard for Infiltration units' based on existing national specifications, at that time (in particular) available in France, Germany, United Kingdom and the Netherlands.
This draft 'Standard for...
2018 Las-Vegas : New testing method for electrofusion welds
Author(s) : Dr. Love Pallon, Dr. Karin Jacobsson, Daniel Ejdeholm, Marie Allvar, Rikard Kärrbrant
This work presents the development of the Full Length Tensile Test (FLTT), a method that enables an objective judgement of welding quality of electrofusion welds by measuring the energy to break (J/mm2 ). In this way a brittle, ductile and transitional mode failure can be differentiated without subjective visual...
2018 Las-Vegas : Sensitivity of strain hardening modulus to molecular structure of polyethylene
Author(s) : Suleyman Deveci, Senthil K. Kaliappan, Joel Fawaz, Umesh Gadgoli
A series of non-commercial bimodal high density ethylene-α-olefin copolymers with systematically controlled molecular parameters over a wide range that would result in extremely low and high strain hardening modulus were prepared and tested
Strain hardening modulus has been published as a standard test method (ISO...
2018 Las-Vegas : Slow crack growth resistance of non-virgin polymers
Author(s) : Andreas Frank, Isabelle J. Berger, Mario Messiha, Carl-Gustaf Ek, Norbert Schuler, Jens-Martin Storheil, Erwin Mayrbäurl, Steve Heeley, Frank Krause, Lodewijk Niemöller, Philippe Gabriëls, Yogesh S. Deshmukh, Florian Arbeiter, Thomas Koch, Gerald Pinter
In order to improve the circular economy of polymers in terms of sustainability and reduced carbon footprint, the increased use of recyclates has become a topic of major importance. Due to their long design lifetimes, pipe applications represent an excellent opportunity to create added value to non-virgin polymers. In...
2018 Las-Vegas : Testing parameters influencing the strain hardening modulus
Author(s) : E.J.W. van der Stok
The effect of eleven different test parameters on the strain hardening modulus was investigated using the Design of Experiments statistical method. The changes in strain hardening modulus due to temperature, tensile drawing speed and the cooling rate after annealing were assessed. The importance of taking account of...