An experimental‐based thermal prediction model for butt fusion welding of polymer pipes.

High‐density polyethylene (HDPE) is one of the most used thermoplastic materials for piping applications, due to its significant advantages. The butt‐fusion process is the most used joining processes for HDPE welding. During the process, the behavior of the material changes. This behavioral change depends on the applied welding process and on the used parameters. Thermal analysis can be used as a tool to reveal and evaluate the modifications of the physical and mechanical properties. In this study, an experimental program was applied to HDPE to assess the effects of different parameters on the welding process including heating temperature, heating duration and the applied strength. Tests are performed according to a full factorial design of experiment (DOE). Mathematical models derived from experimental data are used to establish relationships between the input parameters, such as force and heating duration and the corresponding outputs such as temperature distribution during the different welding phases and the thickness of the molten polymer. The empirical models can be used to implement a control strategy for the temperature and hence quantify the thickness of the molten zone to improve the quality of the weld joint by selecting the appropriate welding conditions for the molten zone. Highlights: High‐density polyethylene piping butt‐fusion joint examination using Infrared imaging.Spatial–temporal distribution of temperature for different phases of the welding process.Mathematical Regression techniques are performed.Thickness of molten polymer is assessed.Results are useful for saving material and improvement of the process. [ABSTRACT FROM AUTHOR]