Abstract: Improved extrusion head for use in forming plastic containers or tubular films (optionally with multi-ply walls) by the extrusion-blowing process. The typical extrusion head used in this process has flat compensating rings bounding a portion of the frustoconical flow passages which ultimately feed the extrusion orifice. These are replaced by spherical segmental rings having a beveled surface in the form of a spherical, conical, toric or ogival shape which bounds said flow passage and thus eliminates stagnating recesses (of the type encountered through use of the prior art flat rings).

Abstract: A process and apparatus for blow-molding hollow bodies in a mold having half-molds which are closed along a mold joint during blow molding and are laterally displaced with respect to one another to open the mold for removal of the formed hollow body. The half-molds are shaped to form a concave bottom on the hollow body and when the half-molds are opened they impose a translation movement on the hollow body. A plug is formed at the bottom of the hollow body during molding which plug is seized by pincers prior to the opening of the mold such that the hollow body is supported by the pincers during mold opening. The pincers are displaced during mold opening, in translation parallel to the plane of the mold joint, over a distance at least equal to that imposed on the hollow body by the half-molds during opening of the mold.

Abstract: The process of the invention essentially consists in supplying sterile gas to an extruded parison confined between the two shells of a mould, this sterile gas being sequentially applied at a first pressure slightly higher than atmospheric pressure, at a second pressure much higher than the first pressure in order to inflate the parison, and at a third pressure which is much lower than the second pressure and corresponds to the desired inflating pressure of the hollow body to be formed.