Special features of ultrasound welding hard plastics with a processing interlayer

Depending upon the possibility of ultrasound welding, thermoplastic materials are divided into hard and soft. Hard plastics are welded by both transfer and resistance ultrasound welding. The experiments show that to obtain a higher quality joint, it is necessary to concentrate the energy of ultrasound oscillations in the welding zone. This is achieved by an artifical decrease of the area of preliminary contact between the specimens. Artifical energy concentrators in the form of a V-shaped protection on one of the components are used widely. One of the variatns of decreasing the actual contact area, resulting in a power concentration, is the cleaning of the contracting surfaces with a rough abrasive paper.