Abstract: A method for manufacturing blown articles is disclosed wherein the article is manufactured from a parison having a high degree of multi-axial orientation. The method permits molecular orientation within the parison to be superposed with orientation imparted during the blowing step, whereby a blown article of greatly improved properties is manufactured.

Abstract: An injection mold cavity is sealed at the mold parting line using a highly exact, narrow annular gap or clearance which restricts flash through of the molten plastic. The seal is designed for molds having a rotatable pin and comprises a fixed seating ring which seats with the mold cavity element, and a journable seal ring having a precisely machined seal face which is narrowly spaced from the lip of the mold cavity and defines the gap dimension with the assistance of the seating ring. The rings float at a unit against a resilient component which controls the seating pressure of the assembly independently of the clamping force of the mold. The foregoing components are unitized within a clamp ring under a preload compressive force with the critical gap dimension precisely built into the unit.

Abstract: Impulse sealing apparatus having a forced cooling cycle following the impulse heating cycle, and comprising in combination, a vortex tube which converts a source of compressed gas at ambient temperature into a cold gas stream, a heat exchanger cooled by the cold gas stream generated by the vortex tube, a second source of pressurized ambient temperature gas communicating with the heat exchanger and cooled thereby, and means for removing the second source gas stream from the heat exchanger and communicating with the impulse sealer for supplying chilled gas thereto.