Back to results
US 2003/0146533 A1Published application
Expanded plastics containers
OwnerBrian Gornellinventor
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
OwnerBrian Gornellinventor
Estimating the term…
The invention relates to the moulding of an expanded or foam plastics container (10) with a rim flange (14) projecting radially outwardly from the container side wall (12) about the mouth (13) of the container. This rim flange is similar to the roll type rim flange of a cup thermo-formed from plastics sheet material and is capable of capturing a snap-on lid. The mould tool for moulding the container (10) comprises male and femal mould parts (16, 17) which are assembled to form a mould cavity (18) defining the container (10). Heating/cooling cavities (21, 24) are provided in the mould parts adjacent the mould cavity and the heating/cooling cavity (21) in the male mould part is connectable via passageways (41, 44, 45) controlled by a valve to the mould cavity (18) adjacent the rim flange moulding zone of the mould cavity. In order to mould the container (10), beads of a plastics material, including a foaming agent, are dispensed into the mould cavity (18), steam supplied via the conduit (15) is injected into the mould cavity via passageways (28) controlled by the valve member (30) to cook the plastics material and mould the expanded plastics container, and during the cook cycle, the valve is controlling the passageways (41, 44, 45) opened to redirect part of the steam flushing the heating/colling cavity (21) to the rim moulding zone to provide an additiona cook facility in this zone.
A method of moulding an expanded plastics container (10) having a bottom wall (11), a sidewall or sidewalls (12) extending upwardly from the bottom wall to a mouth (13) of the container, and a rim flange (14) projecting outwardly from the side wall(s) (12) about the container mouth (13), comprising the steps of disposing plastics material adapted for moulding an expanded product into a mould cavity (18) defining the container to be moulded with the rim flange, introducing steam into the mould cavity at the bottom wall moulding zone of the cavity to cook the plastics material and mould the expanded plastics container, and additionally directing steam into the mould cavity at or adjacent the rim flange moulding zone.
A method according to any preceding claim, wherein the steam directed into the mould cavity (18) at or adjacent the rim flange moulding zone is injected at a location below and closely adjacent the rim flange moulding zone.
A method according to any preceding claim, including the steps of disposing a laminate of flexible sheet material against a mould wall defining an external wall of the container (10) prior to disposing, in the mould cavity (18), the plastics material for moulding the expanded product, whereby the laminate is laminated to the external wall of the moulded container during the moulding cycle.
A mould tool for moulding an expanded plastics container (10) having a bottom wall (11), a sidewall or sidewalls (12) extending upwardly from the bottom wall to a mouth (13) of the container, and a rim flange (14) projecting outwardly from the container side wall(s) (12) about the mouth (13) of the container, said mould tool comprising male and female mould parts (16,17) which are assembled to form a mould cavity (18) defining the container having the rim flange, at least one cavity (21,24) for heating and/or cooling fluid in at least one of the mould parts adjacent the mould cavity and extending adjacent at least that part of the cavity defining the side wall(s) of the container, conduit means (25,35) for supplying steam to the heating/cooling cavity, first passageway means (28) via which steam is injected into the mould cavity and which communicates with the bottom wall moulding zone of the mould cavity, second passageway means (41-47) for directing a portion of the flushing steam from the heating/cooling cavity into the mould cavity at or adjacent the rim flange moulding zone of the mould cavity, and valve means (50) for controlling flow of steam via said second passage means.
A mould tool according to claim 8 or 9, wherein both mould parts (16,17) have heating/cooling cavities (21,24) substantially coextensive with at least that wall of the mould part moulding the side wall(s) (12) of the container.
Dependencies are inferred from the claim text.