eesti teaduste
akadeemia kirjastus
SINCE 1952
Proceeding cover
of the estonian academy of sciences
ISSN 1736-7530 (Electronic)
ISSN 1736-6046 (Print)
Impact Factor (2022): 0.9
Laser beam positioning in quasi-simultaneous laser transmission welding of polymers; pp. 350–360

Simonas Mindaugas Jankus, Regita Bendikienė ORCID Icon

The main objective of this study was to investigate the influence of laser beam positioning on the quality of the polymer joint weld. The laser scan path from the centre of the weld was varied, and its effect on the joint performance was evaluated. Three laser transparent-absorbent polymer pairs with different transmissions were subjected to the following tests: burst pressure, thermal shock, and leakage tests. The tests were performed to evaluate the strength and tightness of the weld. The strongest joints, with an average burst pressure value of 6.4 bar, were obtained by positioning the laser beam at a shift of 0.0 mm, and the lowest joint strength of 5.8 bar at a shift of 0.7 mm. The shift of the laser beam from the centre of the weld affected the heterogeneous melting of the polymers, which increased the heating time required to reach the targeted meltdown: 4.2 s was reached at a 0.0 mm shift and up to 10 s at a 0.7 mm shift. This led to joint overheating, forming of pores, and decreased weld strength. The polymer pair with modulated laser radiation transmission and an absorbent part showed inhomogeneous energy deposition across the weld seam and the formation of the heat-affected zone (HAZ) during quasi-simultaneous welding. The quality of this pair was improved using a 0.0 mm shift and laser power from 330 W to 350 W. As a result, no weld leakage was detected after 50, 75, and 100 thermal shock cycles. 


1. Potente, H., Wilke, L., Ridder, H., Mahnken, R. and Shaban, A. Simulation of the residual stresses in the contour laser welding of thermoplastics. Polym. Eng. Sci., 2008, 48(4), 767–773.

2. Gonçalves, L. F. F. F., Duarte, F. M., Martins, C. I. and Paiva, M. C. Laser welding of thermoplastics: an overview on lasers, materials, processes and quality. Infrared Phys. Technol., 2021, 119, 103931.

3. Acherjee, B. State-of-art review of laser irradiation strategies applied to laser transmission welding of polymers. Opt. Laser Technol., 2021, 137, 106737.

4. Acherjee, B. Laser transmission welding of polymers – a review on welding parameters, quality attributes, process monitoring, and applications. J. Manuf. Process, 2021, 64, 421–443.

5. Bonefeld, D., Schöppner, V., Potente, H., Mahnken, R. and Shaban, A. Residual stresses in the quasi-simultaneous laser transmission welding of amorphous thermoplastics. Polym. Eng. Sci., 2010, 50(8), 1520–1526.

6. Kumar, D., Shekhar Sarkar, N., Acherjee, B. and Kuar, A. S. Beam wobbling effects on laser transmission welding of dissimilar polymers: experiments, modeling, and process optimization. Opt. Laser Technol., 2022, 146, 107603.

7. Laakso, P., Ruotsalainen, S., Otto, G., Olowinsky, A. and Kujanpää, V. Butt welding of transparent polyamide (PA11) with 1.94μm fiber laser. ICALEO, 2013, 175

8. Ruotsalainen, S., Laakso, P., Manninen, M., Purtonen, T., Kujanpää, V. and Salminen, A. TWINQUASI – A new method for quasi-simultaneous laser welding of polymers. ICALEO, 2012, 262–269.

9. Ruotsalainen, S., Laakso, P. and Kujanpää, V. Laser welding of transparent polymers by using quasi-simultaneous beam off-setting scanning technique. Phys. Procedia., 2015, 78, 272–284.

10. Brodhun, J., Blass, D. and Dilger, K. Laser transmission welding of thermoplastic fasteners: influence of temperature distribution in a scanning based process. Procedia CIRP, 2018, 74, 533–537.

11. Wippo, V., Jaeschke, P., Brueggmann, M., Suttmann, O. and Overmeyer, L. Advanced laser transmission welding strategies for fibre reinforced thermoplastics. Phys. Procedia, 2014, 56, 1191–1197.

12. Schkutow, A., Scholle, K.,  Fuhrberg, P. and Frick, T. Scanning techniques for optimized damage tolerance in quasi-simultaneous laser transmission welding of plastics. Procedia CIRP, 2020, 94, 697–701.

13. Nguyen, N.-P., Behrens, S., Brosda, M., Olowinsky, A. and Gillner, A. Laser transmission welding of absorber-free semi-crystalline polypropylene by using a quasi-simulta­neous irradiation strategy. Weld. World, 2020, 64, 1227– 1235.

14. Lakemeyer, P. and Schöppner, V. Laser transmission welding of automotive headlamps without a clamping tool. Weld. World, 2017, 61, 589–602.

15. Ghasemi, H., Zhang, Y., Bates, P. J., Zak, G. and DuQuesnay, D. L. Effect of processing parameters on meltdown in quasi-simultaneous laser transmission welding. Opt. Laser Technol., 2018, 107, 244–252.

16. Nguyen, N.-P., Behrens, S., Brosda, M., Olowinsky, A. and Gillner, A. Modelling and thermal simulation of absorber-free quasi-simultaneous laser welding of transparent plastics. Weld. World, 2020, 64, 1939–1946.

17. Acherjee, B., Kuar, A. S., Mitra, S. and Misra, D. Application of grey-based Taguchi method for simultaneous optimization of multiple quality characteristics in laser transmission welding process of thermoplastics. Int. J. Adv. Manuf. Technol., 2011, 56, 995–1006.

18. Lakemeyer, P., Schoeppner, V., Bates, P., Zazoum, B., Zak, G. and DuQuesnay, D. Matching of laser intensity distribution for laser transmission welding of thermoplastics. Weld. World, 2017, 61, 1247–1252.

19. Wilke, L., Potente, H. and Schnieders, J. Simulation of quasi-simultaneous and simultaneous laser welding. Weld. World, 2008, 52, 56–66.

20. Potente, H., Schöppner, V., Bonefeld, D., Wilke, L. and Hage, C. Experiments regarding the influence of pressure profiling on laser-transmission welding. Weld. World, 2009, 53, R246–R252.

21. Jankus, S. M. and Bendikiene, R. Effect of the meltdown on thermoplastic joint produced by quasi-simultaneous laser transmission welding. CIRP J. Manuf. Sci. Technol., 2022, 39, 104–114.

Back to Issue