1988 年 22 巻 1 号 p. 21-24
Commercially available seamers for plastic tubes generally use heat or high frequency but they have such problems as difficult sealing if the internal surface of the tube is contaminaited with its contents.
Particularly, when the tube content is viscous and has thread-forming properties or is of low viscosity and readily forms droplet the probability of defective sealing due to contamination increases resulting in consumers.
The authors have initiated a study aiming at the development of a perfect sealing method even if the appropriate parts of tube are contaminated with the contents. In this study, heat sealing and high-frequency sealing wealing were not considered to be suitable to solve the problems and methods employing ultrasonic energy were examined under various conditions. Favorable results were obtained by the use of diagonal vibration as the vibration source and a honeycomb shape for the pattern.