Wear & failure modes exhibited by NNPB plungers in the container industry have been related to inappropriate material selection. Problems exist with substrate & coating materials which lead to machine down time, process instability & poor quality. Previous attempts to improve the service of life of NNPB plungers have not examined the process operating characteristics & demanding nature of the application. New substrate & coating materials have been utilized & an assessment of their suitability examined. Initial results from plant trials with modified plungers suggest that improvements in operational performance are achievable. This application, & other components of the mould tooling set, may benefit from improvements which may increase tool life & reduce problems which result from the application of lubricant dopes to glass contact surfaces.
