Heat-shrinkable tubing: What makes it tick?

Twenty-three flexible polyolefin heat shrinkable tubing insulation formulations were subjected to three dose levels of high energy radiation and tested for degree of crosslinking, flammability, tensile strength and elongation, and thermal stability. The effects of component concentration and types on these performance characteristics were determined. Antioxidant concentration and type largely influenced degree of crosslinking as did the sensitizer concentration, whereas stabilizer type and concentration had little effect. Tensile strength and elongation were not largely affected by formulation or radiation dose. High sensitizer concentration tended to improve flame resistance as did higher stabilizer concentrations. Stabilizer type affected flammability. Generally, increased radiation dose tended to improve flame resistance. Thermal stability was improved by changing stabilizer type and lessened by increasing sensitizer concentration or decreasing the antioxidant level.