High speed method for application and curing of optical coating

摘要

Applicants have discovered that the speed of fiber manufacture can be substantially increased by employing a two-step curing process in which the fiber is drawn, coated and exposed to ultraviolet light on-line at high line speeds to effect a partial cure of the coating. After further cooling, the partially cured coating is fully cured by an on-reel exposure to ultraviolet light. The on-reel exposure can take place on the draw tower take-up reel as it is filing with fiber or it can take place off-line after the take-up reel has been filled and removed from the line. The on-reel exposure advantageously takes place either during filling the take-up reel, or during emptying the reel, so that each layer of fiber on the reel is exposed equally to the ultraviolet light. This method of UV illumination improves the energy efficiency in the second exposure by at least a factor of 10 to as much as a factor of 1000. The fiber primary coating pullout strength and mechanical modulus are enhanced.