Photovulcanization of Otherwise Uncured Rubber Components and Effects On Adhesion

Rubber products are used in many life safety critical applications, including tires and large scale water control structures.  Despite rigorous quality control of rubber bulk properties, unanticipated failures of vulcanized multi-component rubber products nevertheless occur and are often traceable to interfacial adhesive failure between components assembled prior to curing.  The durability and structural integrity of rubber products may be compromised by unintended vulcanization prior to assembly and curing.  Bulk premature vulcanization, due to heat exposure history, for example, may be readily detected by Mooney viscosity measurement.  Photovulcanization of the surfaces of rubber components, on the other hand, is not detectable by Mooney viscosity or other bulk property measurements.  The purpose of this study was to establish light exposure limits for an industrial rubber assembly process and to recommend types of lighting and sunlight filtering for new plant expansion/construction.  Light exposure tests, adhesion test results, and recommended light exposure limits are presented.