Cellular plastic cup for thermal insulation - produced by compressing blow moulded concertina top in second stage to reinforcement rim

摘要

Extrusion blow moulding prodn. of thermally insulating vessels of cellular plastics, e.g. drinking cups, comprises first blow moulding to produce a cup with a zigzag shaped concertina near the mouth. The part above it is pared and the concertina is compressed in a second tool by heat and/or pressure to produce a thick reinforcing flange around the rim. Used for prodn. of beakers for hot beverages or cups for ice cream and ice coffee, process eliminates narrow and sharp edges on the rim which makes drinking unpleasant, thus reinforcing the cup.