Preform for producing plastic containers in a stretch blow moulding process and method for producing the preform
AssigneeAlpla Werke Alwin Lehner GmbH & Co. KG
InventorRobert Siegl
Life of this patent
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Abstract
A method for producing a preform and a preform produced by extrusion blow molding for producing plastic containers in a stretch blow molding process and having a neck portion and a body portion closed by a preform base, which portions are separated from each other by a supporting ring protruding from the outer wall. The preform has a body portion of which the outside diameter narrows from the supporting ring in the direction of the preform base.
Claims20
A preform for producing plastic containers in a stretch blow molding process, comprising:
- a neck section having an inside wall;
- a body section adjoining the neck section;
- a preform bottom for closing the body section;
- a supporting ring which protrudes from an outside wall of the preform and separates the neck section from the body section, wherein the preform is produced in an extrusion blow molding process and the body section has an outside diameter which is made tapered from the supporting ring in a direction of the preform bottom;
- and
- a recessed groove formed in the inside wall of the neck section opposite the supporting ring.
A method for producing a preform including a blow-formed neck section, a blow-formed body section adjoining the neck section, a blow-formed preform bottom for closing the body section, a blow-formed supporting ring which protrudes from an outside wall of the preform and separates the neck section from the body section and a blow-formed recessed groove on an inside wall of the neck section opposite the supporting ring, wherein the body section has an outside diameter which tapers from the supporting ring in a direction of the preform bottom, the method comprising:
- extruding a single-layer or multilayer plastic tubing;
- forming a preform having the neck section, body section, bottom, supporting ring, and recessed groove from the plastic tubing with a blow mold, with the neck section and the body section being closed with the preform bottom, and being separated from one another by the supporting ring;
- removing the preform from the blow mold;
- and
- pressing the plastic tubing surrounded by the blow mold for forming the body section with an outside diameter which is tapered from the supporting ring in a direction of the preform bottom with a support pressure against inside walls of the blow mold.
Dependencies are inferred from the claim text.