Safe and Ergonomic Welding Masks by Fast Liquid Crystals

Autor:	Per Rudquist, Sven T. Lagerwall, J.-L. de Bougrenet de la Tocnaye, P. Gautier, Pontus Jägemalm, L. Dupont, B. Caillaud
Rok vydání:	2008
Předmět:	Materials science business.industry High intensity General Chemistry Welding Condensed Matter Physics Ferroelectricity law.invention Arc (geometry) Optics Liquid crystal law General Materials Science Visibility business Intensity (heat transfer)
Zdroj:	Molecular Crystals and Liquid Crystals. 494:195-204
ISSN:	1563-5287 1542-1406
Popis:	Recent developments in welding technology, in particular the high intensity pulsed welding arc, have sharpened the requirements on speed and adjustable attenuation for safe and ergonomic operations. With this advent the conventional welding helmets based on nematic liquid crystals are facing difficulties because the nematics are not responding fast enough to stroboscopically follow the changing intensity of the arc during pulsed welding. We propose here a new generation of welding shutters based on smectic (ferroelectric or antiferroelectric) liquid crystals which are fast enough to be synchronized to follow pulsed arc regimes and hence permitting a better visibility of the object under work. The two varieties of smectic materials used are polymer-stabilized in order to make the device shock-proof, to prevent the formation of specific defects such as stripes and chevrons, and to reduce the back-relaxation time in the antiferroelectric case.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::d22ff5fb4adcfc9f7469321c349ee5e7 https://doi.org/10.1080/15421400802430034 Zobrazit plný text záznamu