Polyethylene has a very wide thermoplastic range between about 140 and 300 °C. However, experience shows that polyethylene has the best (long term-) strength in heating element butt welding at a welding temperature of 200 to 220 °C.

Lower or higher temperatures, respectively, have negative effects on the strength. Therefore, special emphasis has to be put on the measuring of the heating element temperature by means of adequate and regularly calibrated temperature measuring devices.