Alternative Fast Methods to Evaluate the Long-Term Performance in Polyethylene Resins with High Resistance to Crack

Author(s) : Thomas R. Kratochvilla, Raimund Eremiasch, Christoph Bruckner

In the last years effort has been made to develop and standardise new accelerated test methods to evaluate PE 100-RC materials in short times in form of test bars. The two most important developments, the cracked round bar test (CRB test) and the strain hardening test (SH test) were published as final ISO standards in...

Author(s) : Markus Gall, Reinhold W. Lang, Joerg Fischer, Ansgar Niehoff, Steven Schmidt

Despite recent efforts in promoting the utilization of recycled polymeric materials for more diverse and more advanced applications, there are still significant knowledge gaps with regards to the applicability of certain recyclate types for specific “re-use” purposes. When it comes to pipe applications, for instance,...

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...

Author(s) : Joerg Fischer, Paul J. Freudenthaler, Patrick R. Bradler, Reinhold W. Lang, Susan C. Mantell

This research addresses the effect of nucleation on the global aging behavior and the fatigue crack growth (FCG) resistance of commercial alpha- and beta-nucleated polypropylene random copolymer pipe grades (PP-R) when exposed to chlorinated water (5 mg/l free chlorine) at an elevated temperature of 60°C. Comparing...

Author(s) : Suleyman Deveci, Birkan Eryigit, Senthil K. Kaliappan

The effect of eccentricity on the failure time of pipes under hydrostatic pressure test has a significant magnitude that it can easily mislead the evaluation of pipes according to requirement of ISO 4427-2. Therefore, authors propose a maximum relative eccentricity limit of 0.015, even lower, for pipes being tested...

Author(s) : Carlos Domínguez, Álvaro Pérez, Nuria Robledo, Cristina González, Beatriz Paredes, Rafael A. García-Muñoz

Last methodologies for fast evaluation of the SCG resistance on polyethylene pipe materials are analyzed in this work and compared with traditional PENT and FNCT tests. Strain Hardening (SH), Crack Round Bar (CRB) and Accelerated Creep Test (ACT) will be good alternatives for evaluating PE100RC resins. Moreover, SH...

Author(s) : Joerg Fischer, Patrick R. Bradler, Reinhold W. Lang

In the present paper, a novel test system for conducting fatigue crack growth (FCG) experiments under superimposed mechanical-environmental conditions is presented. FCG experiments were performed on a polypropylene (PP) grade and a short-glass fiber reinforced polyamide 66 (PA-GF) grade as model materials. The...

Author(s) : Amanda Hawkins, Jason Lawrence, Xiangli Meng

High Density Polyethylene pipes are used in various applications due to the material’s superior chemical resistance, pressure capability, and ductility. For the material to perform at the optimal design criteria, the connections and fabrications must be fused using repeatable procedures that specify proper fusion...

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...

Author(s) : J.D. Kim, S. Kim , T. Schmutz, C. Malchaire, D. Scholz, K. Keck

Since a few years, pipe producers are facing the challenge to protect their plastic pipe from degradation due to chlorine dioxide. Unfortunately, most existing stabilization solutions are not effective enough to insure the desired lifetime of the material. This study shows how the latest development allow to top-up...

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...

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...

Author(s) : Mingyuan Hu, Dongming Yu, Zhangcheng Chen, Cheng Zhi, Kaige Duan

Studying in barrier property of TLCP/PO alloy and EVOH/PO alloy. Filtrating formulas with extruding alloy into pipes. Trying to coat alloy on pipes and co-extrude into two-layer oxygen barrier plastic pipe. The traditional Ethylene vinyl alcohol copolymer (EVOH) barrier plastic pipe used in internal closed-loop...

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...

Author(s) : Hirofumi Kyutoku, Kazuhisa Igawa, Hidekazu Honma, Sakiko Fukunishi, Hiroyuki Nishimura

There are mainly two grades of polyethylene pipes for hot water supply and heating. The excellent molecular structure polyethylene resins having resistance to stress crack growth are used because hot water is flowed for a long time in both polyethylene pipes. Furthermore, various additives are mixed to prevent the...

Author(s) : Zhang Wei, Wei Ruoqi, Zhou Minghong, Zhou Mingwei,

This article gives a brief introduction of plastic inspection chambers in China. It focuses on the formulation of China's national standard for plastic inspection chambers and conducts the theoretical analysis and data validation of the key technical metrics in the standard for the following three tests: the...

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...

Author(s) : Jie Feng, Michael Petr, Jeff Wenzel, Mark Mirgon, Sam Crabtree, Alan Nakatani

Through tensile tests, simulated orientation, tribology, and finite element analysis, this study explored the effect of temperature, lubrication and applied hydraulic pressure in the PVC orientation process. It was demonstrated that tight control of these parameters is critical in a continuous PVC orientation process...

Author(s) : Ashish M. Sukhadia, Wes Long

Polyethylene (PE) pipe is a frequent choice for transporting slurry solutions. It has proven to have superior wear resistance than other pipe materials. For example, when carrying fine grain slurries, polyethylene pipe has been shown in laboratory tests to be three to five times more wear resistant than steel pipes....

Author(s) : Alex Stolarz

THE PE-RT TECHNOLOGY HAS EVOLVED SINCE IT HAS BEEN FIRST INVENTED AND INTRODUCED TO THE MARKET IN 1982. AN ESTABLISHED TECHNOLOGY FOR HOT AND COLD WATER PIPES USED IN DOMESTIC APPLICATIONS HAS POSITIONED ITSELF WELL WITHIN OTHER MATERIALS DUE TO THE COST EFFICIENT PROCESSING, HANDLING AND PRODUCTION OF PIPES. RECENT...