Method and device for producing preforms with special geometries
AssigneeNetstal-Maschinen AG
InventorsSTEFAN BOCK, BRITTA SCHEUNEMANN
Life of this patent
Estimating the term…
Abstract
Preforms with a neck region and a preform body and having an enlarged geometry in comparison with the cavity of the injection mould are produced by injecting a polymer melt into the mould with a geometry of the cavity in the mould such that the radial extent of an inner space in the Preform body thereby produced is not greater than the radial extent of the inner space in the neck region, the preforms are removed from the open mould by a removal gripper, and the preforms in the removal gripper are inflated using positive pressure such that the geometry of the inflated preform body is larger than the cavity in the injection mould.
Claims18
A method for producing a preform, comprising:
- injecting a polymer melt into an injection mould having a cavity shaped to mold a preform formed with a neck region and defined by an inner space having in a preform body region a radial extent which is not greater than a radial extent of the inner space in the neck region adjacent the preform body region;
- opening the injection mould after a first cooling step;
- removing the preform from the open mould with a removal gripper;
- and
- inflating the preform relative to the cavity of the injection mould with use of a positive pressure so that the preform increases relative to the cavity of the injection mould and a wall of the inflated preform is urged against a wall of a cavity of the removal gripper which is greater than the cavity of the injection mould.
A device for producing a preform, comprising:
- an injection mould having a plurality of cavities provided for formation of preforms formed with a neck region and a preform body, with geometries of the cavities formed such that a free inner space in preform bodies has a radial extent which is not greater than a radial extent of a free inner space in the neck region;
- a plasticizing and injecting device to melt a plastic material and to introduce the plastic material into the cavity of the injection mould, when the injection mould is closed;
- a removal gripper including a plurality of removal sleeves having cavities to receive the preforms formed in the injection mould,
- wherein the cavities of the removal sleeves of the removal gripper are enlarged in comparison with the cavities in the injection mould.
Dependencies are inferred from the claim text.