HIGH-FREQUENCY WELDING OF AN INDUSTRIAL THERMOPLASTIC POLYURETHANE ELASTOMER-COATED FABRIC

Citation
S. Hollande et al., HIGH-FREQUENCY WELDING OF AN INDUSTRIAL THERMOPLASTIC POLYURETHANE ELASTOMER-COATED FABRIC, Polymer, 39(22), 1998, pp. 5343-5349
Citations number
12
Categorie Soggetti
Polymer Sciences
Journal title
ISSN journal
00323861
Volume
39
Issue
22
Year of publication
1998
Pages
5343 - 5349
Database
ISI
SICI code
0032-3861(1998)39:22<5343:HWOAIT>2.0.ZU;2-X
Abstract
The high frequency (27.12 MHz) weldability of a thermoplastic polyuret hane elastomer coated fabric was investigated after determination of i ts dielectric properties. It was shown that at 27.12 MHz, maximum heat ing occurred at 50 degrees C. Subsequent tests were thus carried out a t this temperature. Temperature needs to be measured continuously duri ng the welding operation as the integrity of the weld depends on the c ore temperature. Since conventional methods using probes or adhesive i ndicator strips are disrupted by high frequency (HF) radiation, the in tegrity of the weld obtained by HF was compared to that obtained by im pulse welding at a given temperature under the same conditions of pres sure with the same peeling performance and with the same temperature v ariation after welding, measured by the i.r. thermometer. The highest peeling forces were found when the welding temperature exceeded that o f the melting point (180 degrees C) of the hard segments in the polyme r. The interactions occurring during welding were found to depend on t he temperature. At temperatures below 180 degrees C, the peeling resis tance only derived from entanglements of flexible segments at the inte rface between the two TPU-coated fabrics. At temperatures of 180 degre es C and above, melting and mixing of hard segments produced total coh esion of the two coated fabrics resulting in an enhanced peeling force . (C) 1998 Elsevier Science Ltd. All rights reserved.