Temperature Distributions in Welding Specimens for Ultrasonic Plastic Welding Systems Using Various Frequencies

Abstract

Welding characteristics and temperature increases of plastic welding parts over a frequency range of 27 kHz to 94 kHz are studied. Using 27 kHz, 40 kHz, 67 kHz and 94 kHz ultrasonic plastic welding systems, temperature increase at welded surfaces of 1.0-mm-thick polypropylene plates and polymethyl methacrylate plates is measured using thermocouples inserted between plates, and temperature distributions at cross-sections of lapped plate specimens are measured using a thermotracer. The 94 kHz vibration system used for ultrasonic plastic welding consists of a bolt-clamped Langevin type longitudinal vibration source using four 30-mm-diameter piezoelectric ceramic (PZT) rings, a stepped horn (vibration velocity transform ratio N ¼ 3:0) and a catenoidal horn (N ¼ 3:13) with an 8-mm-diameter welding tip. The other vibration systems have similar configurations. Using a higher frequency system, increases in temperature measured at the welding parts are higher. The maximum temperature increase measured using thermocouples and a thermotracer was over 330 C.KEYWORDS: ultrasonic plastic welding, high-frequency vibration system, frequency characteristics of plastic welding, 27 kHz to 94 kHz vibration system, temperature rise at welding part, temperature distribution at specimen cross section

Stress Analysis of Contact Surface in Ultrasonically Forced Insertion Process

“…High-power ultrasonic technologies have been studied in many fields including wire-bonding, cleaning, [1][2][3] welding, [4][5][6][7][8][9][10][11][12] cutting, [13][14][15][16][17][18][19][20][21][22] and transportation. [21][22][23][24][25] The designs of high power ultrasonic transducers for applications in each media have also been researched vigorously.…”

Frequency Characteristics of Ultrasonic Plastic Welding: (27 kHz to 180 kHz Ultrasonic Plastic Welding Systems)

“…Welding tip diameter of 8.0 mm is corresponding to 0.12 wavelength and vibrates only longitudinally. Radial vibration velocity of the welding tip is negligible compared with longitudinal velocity and the welding tip surface vibrates uniformly in longitudinal vibration mode (1) - (9) . Using 27, 40, 67, 94, 150 and 180 kHz ultrasonic plastic welding systems, welding characteristics are measured and compared.…”

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

“…hen polymer films are joined using an ultrasonic joining machine, the interface temperature between the films increases. [1][2][3][4][5][6][7][8] The heat production by the direct friction using the joining machine was previously interpreted as a major origin of the interface temperature increase. Watanabe et al studied the heat production mechanism theoretically and concluded that the heat production by the friction at the interfaces was more dominant than that by the viscosity.…”