Analysis of the Effects of Weld Melt Duration on Joint Integrity and Surface Quality During Profile Milling

Research into technological processes, such as welding, provides the basis for optimising the strength and quality of PVC joints, which are becoming increasingly important in the context of sustainable construction. The study analysed the influence of welding parameters on the quality and strength of the welds of PVC window profiles reinforced with glass fibre composite. The variable parameters were welding time (21–25 s) and composite milling depth (up to 1 mm). The constant parameters were a welding temperature of 264 °C and a head feed rate of 0.25 mm/s. The results showed that the most favourable results were achieved with a composite milling depth of 1 mm and a melting time of 22 s, which provided the highest average failure load values and met the strength requirements. Additionally, the white welds confirmed that the welding process had been carried out correctly, with no depolymerisation or material degradation occurring. In contrast, milling depths of less than 1 mm or no milling depth at all resulted in problems with dimensional tolerance. In addition, overloading of the welding machine during the welding process was observed for composite milling depths of less than 1 mm and a melting time of 22 s. The results of the study highlight the need for further analysis of the influence of other process parameters, including welding temperature.