Product Code: ICA12_706

Twinquasi – A New Method for Quasi-Simultaneous Laser Welding of Polymers
Authors:
Saara Ruotsalainen, VTT Technical Research Centre of Finland; Lappeenranta Finland
Petri Laakso, VTT Technical Research Centre of Finland; Lappeenranta Finland
Matti Manninen, Lappeenranta Univ. of Technology; Lappeenranta
Tuomas Purtonen, Lappeenranta Univ. of Technology; Lappeenranta
Veli Kujanpää, VTT Technical Research Centre of Finland; Lappeenranta
Antti Salminen, Lappeenranta Univ. of Technology; Lappeenranta
Presented at ICALEO 2012

Quasi-simultaneous laser welding (QSLW) of polymers has been studied, developed and used in industry for many years. The process has high flexibility and a lot of advantages but it has some limitations, especially when short lead time and welding time is required. The short welding time requires a scanner with an extremely high speed and accuracy which usually limits the dimensions of the joint and products to be welded. This paper presents a new method for quasi-simultaneous laser welding of polymers which enables welding of larger components within a short welding time. The paper demonstrates a QSLW-process with two lasers and optical scanners (TWINQUASI) and compares the performance to those of traditional QSLW. Results show that with this method, the length of the weld can be doubled within the same welding time while still keeping the same scanning frequency as with conventional QSLW-process. It is shown that with the TWINQUASI method larger components can be welded with quasi-simultaneous method than what has been shown earlier. Another advantage of the process is the ability to program focal points of both lasers individually. Because of this, the TWINQUASI method also enables a variation of the weld width within one weld seam giving even more flexibility to the process.