DOUBLE WALLED CONTAINER AND METHOD OF MANUFACTURE
A double walled container comprising an inner container having a sidewall ( 52 ) and a base ( 54 ) connected thereto, and an outer container ( 1 ) having a sidewall ( 2 ) and a base ( 4 ) connected thereto and arranged to accommodate the inner container, whilst defining a gap therebetween. The sidewall ( 2 ) of the outer container has a securement region, which is formed to have a smaller diameter compared with the diameter of the sidewall ( 52 ) of the inner container. The inner container may take the form of a filled beverage can ( 90 ), which is sealed by an end ( 70 ) seamed thereto and is subsequently inserted into a larger outer can during the final stage of production.
1 . A double walled container comprising:
an inner container having a sidewall and a base connected thereto,
an outer container having a sidewall and a base connected thereto and arranged to accommodate the inner container, whilst defining a gap therebetween,
wherein a portion of the diameter of the sidewall of the outer container is less than the diameter of the sidewall of the inner container and thereby the inner container is secured within the outer container.
2 . A double walled container according to claim 1 , wherein the sidewall of the outer container is formed inwardly to provide a portion of reduced diameter to secure the inner container and the outer container together.
3 . A double walled container according to claim 1 , wherein the sidewall of the inner container is substantially cylindrical and the free-end of the sidewall of the outer container defines a rim that is inwardly formed to a diameter less than the diameter of the cylindrical sidewall of the inner container.
4 . A double walled container according to claim 3 , wherein the rim is formed into a curl.
5 . A double walled container according to claim 1 , wherein the sidewall of the inner container has one or more indentations around its circumference and a portion of the outer container is arranged to conform to the reduced diameter of the indentations in the sidewall of the inner container.
6 . A double walled container according to claim 1 , wherein the gap between the sidewall of the outer container and the sidewall of the inner container is filled with thermal insulation and/or a support structure.
7 . A double walled container according to claim 1 , wherein the gap between the sidewall of the outer container and the sidewall of the inner container is pressurised.
8 . A double walled container according to claim 1 , wherein the inner and outer containers are made of metal.
9 . A method of manufacture of a double walled container, comprising the steps of:
taking an inner container having a sidewall and a base connected thereto,
forming an outer container adapted to accommodate the inner container,
sliding the inner container into the outer container, to define a gap therebetween,
forming the outer container to a diameter less than the diameter of the sidewall of the inner container and thereby securing the inner container within the outer container.
10 . A method of manufacture of a double walled container according to claim 9 , wherein a product is filled into the inner container and sealed therein, before sliding the filled and sealed inner container into the outer container.
11 . A method of manufacture of a double walled container according to claim 9 , wherein the inner and outer containers are made from sheet metal.
12 . A method of manufacture of a double walled container according to claim 11 , wherein the sheet metal is coated with a coating containing organic materials or polymers.
13 . A method of manufacture of a double walled container according to claim 12 , wherein the coating applied to the inner and/or outer containers is fused together after the outer container is necked in to a diameter less than the diameter of the sidewall of the inner container.