DOI: 10.1615/ICHMT.2004.RAD-4
ISBN Print: 978-1-56700-207-2
ISSN Online: 2642-5629
ISSN Flash Drive: 2642-5661
RADIATIVE HEAT TRANSFER IN PLASTIC WELDING PROCESSES
要約
This lecture is a brief review of recent developments in plastic welding processes. The specific focus of the paper is on a novel CO2 laser welding procedure from the point of view of heat transfer involving simultaneous radiation and conduction phenomena. The principle and features of the process for both the experiments using a CO2 laser as a radiation source and the numerical simulations considering combined radiation and conduction heat transfer simultaneously in welding process are discussed. The feasibility of this procedure is confirmed by applying the concept to the plastic films with combination of infrared radiation absorbing heating and thermal diffusion cooling processes. A solid material transparent to infrared radiation with a high thermal diffusivity is used as a heat sink in contact with irradiated surface of overlapped thermoplastics during radiation heating. The procedure is able to achieve both high weld strength and excellent surface appearance without causing surface thermal damage as often suffered in conventional direct infrared radiation welding processes. In addition, pigmentation in welding material to increase absorption of radiation is unnecessary for this method.