Preforms and method for producing preforms
AssigneeAlpla Werke Alwin Lehner GmbH & Co. KG
InventorRobert Siegl
Life of this patent
Estimating the term…
Abstract
The invention relates to a preform for producing a plastic container in a 2-stage stretch blow molding method, said preform having a preform body that extends along a central axis and that comprises: a first end a second end that lies opposite the first end, wherein the first end is closed and a neck part with a pouring opening adjoins the second end; and an inner wall that delimits an interior of the preform. Along a length of at least 30 mm of the interior, every point of the inner wall is at a distance of less than 3.5 mm from the central axis. Also disclosed are a suitable method and a device for producing such a preform.
Claims19
A preform for producing a plastic container in a two-step injection stretch blow molding process, comprising:
- a preform body extending along a central axis thereof and having a first end and a second end opposite the first end, the first end being closed by a preform bottom;
- a neck part haying a pour opening connected to the second end of the preform body;
- and
- an inside wall bordering an interior space of the preform body, each point on the inside wall in the interior space being less than 3.5 mm away from the central axis for a length of at least 30 mm.
A method for producing a preform;
- comprising:
- completely filling a cavity of a mold
- with a hot molten polymer composition, wherein the cavity is formed by a female mold and a core, wherein the female mold defines an exterior shape of a preform and wherein the core defines a shape of an interior space of the preform in an area of a neck part;
- cooling the hot polymer composition by contact with the female mold and the core, wherein volume shrinkage of the polymer composition is induced by cooling the polymer composition;
- and
- inserting a pin into the polymer composition along a central axis of the preform to be produced, wherein due to the insertion of the pin the volume shrinkage is compensated, wherein the pin defines at least a partial area of the shape of the interior space of the preform in an area of the preform body, and wherein each point on the inside wall of the preform to be produced is a distance of less than 3.5 mm away from the central axis along a length of at least 30 mm;
- and
- removing the preform from the cavity, the preform comprising:
- a preform body extending along the central axis thereof and having a first end and a second end opposite the first end, the first end being closed by a preform bottom;
- the neck part having a pour opening connected to the second end of the preform body;
- and
- an inside wall bordering an interior space of the preform body, each point on the inside wall in the interior space being less than 3.5 mm away from the central axis for a length of at least 30 mm.
A device for producing a preform, comprising:
- a mold with a cavity, wherein
- the cavity is formed by a female mold and a core;
- the female mold is designed to define an exterior shape of the preform,
- the core is designed to define a shape of an interior space of the preform in an area of the neck part;
- a pin that can be inserted from the core into the cavity along a central axis of the preform to be produced;
- the pin designed to define at least a partial area of the shape of the interior space of the preform in an area of the preform body, wherein each point on the pin is a distance of less than 3.5 millimeters away from the central axis of the preform to be produced along a length of at least 30 millimeters
- the preform comprising:
- a preform body extending along a central axis thereof and having a first end and a second end opposite the first end, the first end being closed by a preform bottom;
- a neck part having a pour opening connected to the second end of the preform body;
- and
- an inside wall bordering an interior space of the preform body, each point on the inside wall in the interior space being less than 3.5 mm away from the central axis for a length of at least 30 mm.
Dependencies are inferred from the claim text.