An avid 48-year-old golfer with end-stage, tricompartmental osteoarthritis of the right knee is preparing to undergo total knee arthroplasty given an inability to continue playing golf despite attempting all forms of non-operative management. The treating surgeon plans to use a cruciate-retaining design with a vitamin-E-diffused, highly-cross-linked polyethylene insert. When counseling the patient pre-operatively, the patient asks about the manufacturing process for the polyethylene insert. You inform him that it is gamma-irradiated in an inert, oxygen-depleted environment and subsequently annealed to achieve improved wear properties. Which of the following steps in the manufacturing process increases the risk of fatigue failure of the polyethylene component?