Eye shield for arc welders - consists of transparent plastic screen contg. fluorescent dye, ultraviolet absorber, and fire retardant

摘要

The shield is sufficiently transparent for observation of a workpiece, but protects the eyes of an observer; it consists of a sheet or plate of a transparent organic plastic which contains a dye permitting the transmission of min. 70% of the incident light of wavelength (WL) 600-1400 nm. The plate also contains ultraviolet absorbers, fire retardants, and plasticizers. The relative transmission of the plate is max. 0.01 at 450 nm; max. 0.05 at 491 nm; and min. 0.7 at 600 nm. The dye is pref. a fluorescent material emitting light of 450-700 nm and/or metallic azo dyes; the fluorescent material is esp. a migratory dye. The plastic plate matrix pref. also contains discontinuities with a refractive index (RI) differing from the RI of the matrix by min. 0.2 and scattering 5-50% of the transmitted light. Max. clarity of observation is combined with eye safety even during long observation times.