Thermal Welding by the Third Phase Between Polymers: A Review for Ultrasonic Weld Technology Developments

• Published in: Polymers Vol. 12; no. 4; p. 759
• Main Authors: Qiu, Jianhui, Zhang, Guohong, Sakai, Eiichi, Liu, Wendi, Zang, Limin
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 31.03.2020; MDPI
• Subjects: Adhesive bonding; Chain dynamics; Dissimilar materials; Friction welding; Heat; Interdiffusion; Lasers; Molecular motion; Morphology; Polylactic acid; Polymers; Polymethyl methacrylate; Review; Stress concentration; Surface stability; Tensile strength; Thermal stability; thermal welding by the third phase (TWTP); thermoplastic welding technology; Ultrasonic welding; ultrasonic welding (USW); Welded joints; welding between dissimilar materials; thermoplastic welding technology; ultrasonic welding (USW); thermal welding by the third phase (TWTP); welding between dissimilar materials
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym12040759

Ultrasonic welding (USW) is a promising method for the welds between dissimilar materials. Ultrasonic thermal welding by the third phase (TWTP) method was proposed in combination with the formation of a third phase, which was confirmed as an effective technology for polymer welding between the two dissimilar materials compared with the traditional USW. This review focused on the advances of applying the ultrasonic TWTP for thermoplastic materials. The research development on the ultrasonic TWTP of polycarbonate (PC) and polymethyl methacrylate (PMMA), polylactic acid (PLA) and polyformaldehyde (POM), and PLA and PMMA are summarized according to the preparation of the third phase, welded strength, morphologies of rupture surfaces, thermal stability, and others. The review aimed at providing guidance for using ultrasonic TWTP in polymers and a basic understanding of the welding mechanism, i.e., interdiffusion and molecular motion mechanisms between the phases.