Prodn. of synthetic resin hollow mouldings, esp. bottles - by cutting extruded tube off between nozzle and holding point then closing end by action of mandrel

摘要

In the production of synthetic resin hollow mouldings, such as bottles, the molten resin is extruded from a die in a form of tube, (a parison). It is cut off by a cutter blade and held in a mould. A fluid is blown into the parison to form a hollow product. The novelty is that the parison is held at a position away from the nozzle of the die and cut off at a position nearer to the nozzle than the holding point. The cut end of the parison is closed to form a bottom of the parison, by moving a mandrel inserted into the die, in such manner that the top end of the mandrel presses the end section of the parison into a mandrel receiver. Method reduces wastage of material.