A Novel Manufacturing Method for Thermoplastic Polyurethane Welding Using CO2 Laser

Thermoplastic Polyurethane (TPU) is a kind of material with some advantages such as high elasticity, high toughness, high wear resistance and good biocompatibility. It is widely used in the field of food packaging, medical devices, software robots and so on. The conventional processing of thermoplastic polyurethane is done by high frequency machine or manual which lack flexibility. It is time consuming and highly expensive. This paper presents a novel manufacturing method for cutting/welding TPU with CO2 laser. This method is fast and easy to realize complex cutting/welding curve. One of the merits of using laser cutting/welding is its ability to re-run the same procedure with greater precision and accuracy. The objective of this research work is to verify the effect of different cutting/welding parameters of TPU with CO2 laser in order to achieve the best result from largest cutting/welding strength. The maximum power of CO2 laser is 130W. Laser power varies at 10%, 50%, 90% of maximum power. Cutting/Welding speed varies at 10, 40, and 70mm/s. Laser spot diameter varies at 0.5, 1.0 and 1.5mm. Material thickness varies at 0.03, 0.05, 0.10mm. The use of Taguchi Method's Orthogonal Array L (34) was adopted to combine multiple factors. In order to obtain good result, all tests were conducted 3 times. From ANOVA analysis, and Signal to Noise(S/N) Ratio, the material thickness has greater influence factor in cutting/welding process of TPU using CO2 laser. Others in descending order are spot diameter, cutting/welding speed, and laser power respectively.