Abstract: Gamma irradiation resistant propylene/ethylene copolymer compositions are provided comprising: i) a propylene/ethylene copolymer comprising from about 2 to about 3.5 wt. % ethylene; ii) from about 800 ppm to about 1200 ppm of one or more light stabilizers; iii) from about 300 ppm to about 1200 ppm of one or more acid scavengers; iv) from about 1600 ppm to about 2200 ppm of aluminum, hydroxybis[2,4,8,10 tetrakis (1,1-dimethyl(ethyl)-6-hydroxy-12H dibenzo[d,g][1,3,2] dioxaphoshocin 6-oxidato]; and v) a sufficient amount of one of more viscosity modifiers to break down the resulting polymer viscosity to a melt index from about 23 to about 31 g/10 minutes measured at about 230° C./2160 g.

Abstract: Methods and systems for relaxing stresses in polymeric articles by application of laser energy are disclosed.