Laser welding of polyethylene films

Abstract

Currently, the scope of application of laser welding is constantly expanding, in particular for the connection of polymer films of different types. This method of welding successfully competes with traditional methods, such as welding with heated tools and ultrasound in the light, medical, food and packaging industries. Advantages of laser welding are the absence of direct contact between the energy source and the heated surfaces and the ability to vary the intensity of heating by adjusting the temperature of the radiator and the distance to it. Currently, the most common laser welding technology is the transmission (permeable) method for overhead joints, which uses the effect of transparency of some polymeric materials for the laser beam. The transmission welding of low-power short-focus laser of polyethylene films of different types is carried out in the work. Knee welding was performed using a diode laser with a power of 1 W with a wavelength of 532 nm (green color of the visible light range). The laser on the clamping platform was moved along the connection line by means of a mechanical trolley. During welding, a 0.8–1 mm wide seam was formed and a slight convexity to the outside due to the expansion of the molten polymer material. Experimental studies of the influence of the main parameters of the laser welding process on the morphology of joints of polyethylene films of grades T and H. It is shown that welding laser films in the range of 0.015–0.1 mm does not require expensive laser equipment. A laser with a power of no more than 1 watt is enough to make a good connection. The quality of the welded joints of the films was evaluated by visual inspection, examination under a microscope and tear tests. Studies of experimental welds have shown their strength at the level of the base material.