Stretch blow molding process
AssigneeAlpla Werke Alwin Lehner GmbH & Co. KG
InventorRobert Siegl
Life of this patent
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Abstract
A stretch blow molding process for producing a plastic container from a preform, having an elongated, tubular preform body, extending along a center axis. The first end of the preform body is closed by a preform bottom and the second end is adjoined by a neck part with a pouring opening. A wall, bounds an interior space of the preform. The preform body is heated and introduced into a cavity of a blow mold. A stretching mandrel enters the preform until the stretching mandrel tip reaches the preform bottom. The preform body and the preform bottom are stretched by the stretching mandrel. The preform body and the preform bottom are deformed by introducing a fluid into the preform under pressure. The stretching mandrel makes contact with the inner side of the wall in the region of the preform body.
Claims25
A stretch blow molding process for producing a plastic container from a preform, comprising:
- providing a preform having an elongated tubular preform body, which extends along a central axis of the preform and has a first end and a second end essentially opposite the first end, wherein the first end is closed by a bottom of the preform and a neck part with a spout opening is connected to the second end, and having a wall bordering an interior space of the preform and having an inside and an outside;
- heating the body of the preform to at least 70° C.;
- inserting the preform into a cavity in a blow molding mold;
- inserting a stretching mandrel comprising a stretching mandrel body and a stretching mandrel tip into the preform until the stretching mandrel tip reaches the preform body, the stretching mandrel in the form of an essentially continuous cylinder having a substantially constant diameter from the stretching mandrel tip to at least up to the spout opening of the preform when stretched;
- stretching the body of the preform and the bottom of the preform with the stretching mandrel in the cavity,
- shaping the preform body and the bottom of the preform according to the cavity by introducing a fluid into the preform under pressure;
- and
- contacting an inside of the wall in an area of the preform body in at least one predetermined partial area with the stretching mandrel, while it is being inserted into the preform, until it reaches the bottom of the preform, the stretching mandrel coming into contact with at least 30% of an inside of the wall in an area of the body of the preform when the stretching mandrel reaches the bottom of the preform.
A stretch blow molding process for producing a plastic container from a preform, comprising:
- providing a preform having an elongated tubular preform body, which extends along a central axis of the preform and has a first end and a second end essentially opposite the first end, wherein the first end is closed by a bottom of the preform and a neck part with a spout opening is connected to the second end, and having a wall bordering an interior space of the preform and having an inside and an outside;
- heating the body of the preform to at least 70° C.;
- inserting the preform into a cavity in a blow molding mold;
- heating a stretching mandrel comprising a stretching mandrel body and a stretching mandrel tip outside of the blow molding mold before insertion into the preform
- inserting the stretching mandrel into the preform until the stretching mandrel tip reaches the preform body;
- stretching the body of the preform and the bottom of the preform with the stretching mandrel in the cavity,
- shaping the preform body and the bottom of the preform according to the cavity by introducing a fluid into the preform under pressure;
- contacting an inside of the wall in an area of the preform body in at least one predetermined partial area with the stretching mandrel, while it is being inserted into the preform, until it reaches the bottom of the preform.
Dependencies are inferred from the claim text.