The NNPB process was introduced to gain better control over glass distribution in the container. The improved control over glass distribution has enabled significant reduction in glass weight up to 33% without adversely affecting mechanical performance of the container. A key component in the process is the plunger, used to form the cavity in the parison during forming. The function of the plunger is to evenly distribute the glass within the blank mould cavity & aid the removal of thermal energy from internal surface of the parison. Whilst there has been considerable attention given to requimerments of the glass, there has been little attention given to the plunger material, cooling system design & plunger operating environment. This work gives an overview of some problems associated with NNPB process & recent research carried out.
