초록 ▼

Thermally processable plastics tubs (10) filled with a liquid or semi-liquid product so as to leave a headspace are closed by preformed lids (12) which are heat-sealed to their peripheral flanges when the headspace is filled with steam. In order to prevent the steam from affecting the heat-sealing o

Thermally processable plastics tubs (10) filled with a liquid or semi-liquid product so as to leave a headspace are closed by preformed lids (12) which are heat-sealed to their peripheral flanges when the headspace is filled with steam. In order to prevent the steam from affecting the heat-sealing operation, the lid flanges are wider than the container flanges, and their projecting annular parts (29) are engaged so as to form a barrier separating the steam from the heated heat-sealing head.

대표청구항 ▼

A method of closing a plastics container of a product, which method comprises: (a) locating a lidding material which is heat-sealable to the container, over a mouth-defining rim of the container, (b) directing steam between the lidding material and the container rim and into the space between the li

A method of closing a plastics container of a product, which method comprises: (a) locating a lidding material which is heat-sealable to the container, over a mouth-defining rim of the container, (b) directing steam between the lidding material and the container rim and into the space between the lid and the product in the container to purge said space of gas, (c) and heat sealing the lidding material to the rim using a heated element located on the side of the lidding material remote from the container characterised in that: (d) the lidding material is in the form of an individual lid for the container, and (e) during step (b) the circumference of said lid is maintained in engagement with an element which, in conjunction with the lid, forms a moisture barrier between the steam-containing region and the heated element so as to keep steam away from the heated element.