APPLICATION OF ADVANCED COATINGS TO NARROW NECK PRESS AND BLOW PLUNGERS IN THE GLASS CONTAINER INDUSTRY

Wear and failure modes exhibited by narrow neck press and blow (NNPB) plungers in the glass container industry have been related to inapprop riate material selection. Problems exist with substrate and coating ma terials which lead to machine down time, process instability and poor product quality. Previous attempts to improve the service life of NNPB plungers have not examined the process operating characteristics and demanding nature of the application. New substrate and coating materia ls have been utilized and an assessment of their suitability for this application examined. Initial results from plant trials with modified plungers suggest that improvements in operational performance are achi evable. This application, and other components of the mould tooling se t, may benefit from improvements which may increase tool life and redu ce the problems which result from the application of lubricant dopes t o glass contact surfaces.