			Home About us Contact

Ultrasonic Welding (ultrasonic + welding)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Ultrasonic Metal Welding of Aluminium Sheets to Carbon Fibre Reinforced Thermoplastic Composites (Adv. Eng.

ADVANCED ENGINEERING MATERIALS, Issue 1-2 2009
Mater.
The Cover shows a hybrid joint for multi-material lightweight components realized by ultrasonic metal welding at the Institute of Materials Science and Engineering at the University of Kaiserslautern. Ultrasonic welding is one innovative technology for joining carbon fibre reinforced polymers (CFRP) with sheet metals like aluminium alloys or aluminium plated steels. The achievable mechanical properties of the ultrasonic welded joints were carried out by using statistical test methods. One example for the evaluation of the welding results is presented on the left hand side of the Cover. Additionally a scanning electron micrograph of the bonding zone of an aluminium/CFRP-joint is shown in the background. More details about the ultrasonic welding technique can be found in the article of F. Balle, G. Wagner and D. Eifler on page 35 of this issue. [source]

Ultrasonic welding of advanced thermoplastic composites: An investigation on energy-directing surfaces

ADVANCES IN POLYMER TECHNOLOGY, Issue 2 2010
Irene Fernandez Villegas
Abstract Ultrasonic welding is considered as one of the most promising welding techniques for continuous fiber-reinforced thermoplastic composites. Intermolecular friction within the bulk, resulting from the application of ultrasonic waves applied on the surfaces, generates the heat required for welding to take place at the interface of the joining members via the so-called "energy directors" (EDs). Energy directors consist of resin protrusions or artificially produced asperities on the composite surfaces and play an important role both in the welding process and in the quality of the resulting welds. This paper presents the results of a study on the effects of configuration of different EDs on the ultrasonic welding of carbon fiber/polyetherimide advanced thermoplastic composites in a near-field setup. Triangular EDs were molded on the surface of consolidated composite laminates with a hot platen press. Single lap-shear-welded samples were produced to investigate the influence of the orientation of the EDs with respect to the load direction, as well as the configuration of multiple EDs. The results indicate that the configuration of multiple transverse EDs was more effective in covering the overlap area, once the resin has melted, causing only a minimum fiber disruption at the welding interface. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:112,121, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20178 [source]

Effects of the shape of the energy director on far-field ultrasonic welding of thermoplastics

POLYMER ENGINEERING & SCIENCE, Issue 1 2000
Yew Khoy Chuah
An energy director is widely used in ultrasonic welding to increase the welding speed and quality. In the present work, three different types of energy directors were studied,namely, a triangular, a rectangular, and an innovative semicircular energy director. Experiments were performed using far-field test samples made of amorphous-type (ABS) and semicrystalline-type (PE) thermoplastics. It was found that the weld time is an important parameter of ultrasonic welding for the three types of energy directors studied. Weld pressure has different effects for the types of plastics tested. Increasing the weld pressure will decrease the welding efficiency for ABS. But for PE, increasing the weld pressure to four bars will increase the welding efficiency. The shape of the energy director was found to significantly affect the welding efficiency. In comparison, a semicircular shape was found to yield the highest welding efficiency under the same welding conditions and the triangular shape the lowest. Temperature measurements at the triangular energy director during the welding process indicate that the energy director absorbed 48.5% of the welding energy for ABS and 21.1% for PE. The different energy absorption rates are probably due to the difference in elasticity and viscosity between amorphous (ABS) and semicrystalline (PE) plastics. [source]