Certification of Thermoplastic Sheet Butt Welding Machine
Vesala, Lauri (2015)
Vesala, Lauri
Arcada - Nylands svenska yrkeshögskola
2015
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2015060512591
https://urn.fi/URN:NBN:fi:amk-2015060512591
Tiivistelmä
The aim of this work was to argue whether the certification process used in Finland for butt welded products is sufficient for ensuring quality welds. This topic was approached by reviewing the plastic joining technical codes for butt welding in order to understand the correct butt welding process, the weld testing procedures and the common weld im-perfections. To get an understanding of the certification process, the involved bodies were reviewed along with the functions of notified bodies, the roles of standards, and the function of certification markings.
For the practical part of this project a welding procedure test (WPT) was conducted with PRP-Plastic Oy on the Wegener SM 440 TPQ thermoplastic sheet butt welding machine. The procedure test required the creation of test samples for PP, PVC and PVDF sheets of various thicknesses, for which the technical codes were used as a guide. The samples were then sent to Häme UAS for tensile testing on their accredited testing machine. Af-terwards, the results are sent to Inspecta, a notified body, along with the welding proce-dure specifications for certification. A bending test, independent to the WPT, was con-ducted on some of the samples to test the ductility of the welds.
It was noticed that the welding process for making the weld samples followed the guide-lines of the technical codes very closely, while the welding procedure tests were much different to the codes. However, due to practical reasons and the vast amount of infor-mation that it provides, it is reasonable to use a tensile test as the sole evaluator for the welding procedure test.
For the practical part of this project a welding procedure test (WPT) was conducted with PRP-Plastic Oy on the Wegener SM 440 TPQ thermoplastic sheet butt welding machine. The procedure test required the creation of test samples for PP, PVC and PVDF sheets of various thicknesses, for which the technical codes were used as a guide. The samples were then sent to Häme UAS for tensile testing on their accredited testing machine. Af-terwards, the results are sent to Inspecta, a notified body, along with the welding proce-dure specifications for certification. A bending test, independent to the WPT, was con-ducted on some of the samples to test the ductility of the welds.
It was noticed that the welding process for making the weld samples followed the guide-lines of the technical codes very closely, while the welding procedure tests were much different to the codes. However, due to practical reasons and the vast amount of infor-mation that it provides, it is reasonable to use a tensile test as the sole evaluator for the welding procedure test.