Takehiro Hosokawa

Ultrasonic Heating of Poly(ethylene terephthalate), Polypropylene, High-Density Polyethylene, and Low-Density Polyethylene Films

The ultrasonic heating rates of poly(ethylene terephthalate) (PET), polypropylene (PP), high-density polyethylene (HDPE), and low-density polyethylene (LDPE) films are reported. For this measurement, we used an experimental set-up consisting of an ultrasonic vibrator, a horn, and a radiation thermometer. Because the horn did not touch the film surfaces, the temperature increase was only by the ultrasonic vibration transmitted from the horn. The highest and lowest temperature increase were recorded for the PET and LDPE films, respectively. The temperature increase was related with the viscosity of the polymer films.

Temperature Increase at the Interface between Ultrasonically Joined Poly(ethylene terephthalete) Films

While studying the ultrasonic joining of poly(ethylene terephthalate) (PET) films, we measured the temperature increase at the interface between two films during ultrasonic joining. To measure the temperature, we developed an experimental set-up consisting of an ultrasonic welder and a radiation thermometer, and measured the time dependence of the temperature changes at the interface. There was an exothermic reaction while the films were joined. We inspected cross sections of the joined parts, and found an intermediate layer. This intermediate layer is an element of a unique structure involved in ultrasonic joining. Conceivably, in the intermediate layer, PET molecules are involved in Brownian motion.