Method for producing a hollow body by the extrusion and blowing of plastics material and unit for carrying out said methods

Abstract From the Canadian patent

Method for producing a hollow body by the extrusion and blowing of plastics material, comprising feeding plastics material to an extruder and an extruding die at the outlet of which there is obtained a parison roughly producing the shape of the hollow body, and blowing air into the parison thereafter introducing, this parison into a mould having a cavity whose shape corresponds to the shape of the body to be moulded wherein, with the mould, open, air is blown into the parison until its length is equal to the length of the desired hollow body, then the blowing air is cut off so as to obtain a deflated parison the mould is closed and, air at high pressure is blown into the parison so as to …