Hot fill container
AssigneeTjandra Limanjaya
InventorTjandra Limanjaya
Life of this patent
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Abstract
A PET hot fill bottle (2) has a neck (3) and a body (4). It is stretched and blown into a cavity (14), with internal pressure holding the body against the cavity. During a first period, the cavity is heated to 100° to 160° C. for between 3 to 7 seconds to relax stresses in the body. During a second period the cavity is cooled to 60° to 120° C. for 4 to 8 seconds. This solidifies it—without introducing stresses—so that it can be removed from the mould. The resulting bottle is heat stable when filled with water close to its boiling point, namely at 92° C. to 98° C. For the rapid heating and cooling of the mould cavity, it is provided with two series of passages (16, 17). The former house ohmic heaters (18); whilst the latter are connected to water and air supply lines (19, 20).
Claims11
A method of forming a plastics material container comprising the steps of:
- blowing a heated, injection moulded preform to finish formed shape in a mould imparting the finish formed shape to the body of the container,
- holding the blown container in contact with the mould at elevated temperature for a first period after blowing to allow internal blowing stresses to relax,
- passing water through the mould so as to reduce the mould temperature to a lower temperature,
- after passing the water through the mould, passing air through the mould so as to hold the mould at the lower temperature for a second period,
- holding the container in contact with the mould during said second period to cool the container below its solidification temperature without internal stressing of the container, and
- removing the container from the mould.
Dependencies are inferred from the claim text.