Method of making container article having heatable stratified material portion

Claim 1

A method of making a closed container article having a plurality of parts joined along closure seams comprising the steps of: providing a first article part having a container article element region and a first thermally joinable region; providing a second article part by coextrusion through layer forming dies by, providing a plurality of fusible thermoplastic compositions at first locations removed from the layer forming dies, moving the compositions from the first location towards the dies, the movement of at least one of the compositions being accompanied by an agitation thereof, uniformly providing in one of the compositions during its movement toward the die and by means of its agitation, a particulate ferromagnetic oxide susceptor; heating the compositions to a malleable and fusible state during the movement, and forcing the compositions through respective dies into intimate contact with each other while in the malleable and fusible state to form a sheet having joined stratified layers of the compositions coextensive with its dimensions, forming the stratified sheet into a second container article part having a container article element region and a second thermally joinable region contiguous with the article element region, each of said regions containing the susceptor laden layer; juxtapositioning the first and second article parts so that the thermally joinable regions of said first and second article parts are contiguous along a closure seam; applying an alternating magnetic field to the thermally joinable region of said second article part to heat the regions; and bringing the contiguous regions of the first and second article parts into contact to effect thermal joinder between the two to seal the part into the container article.

Claim 2

A method of making a closed container article having a plurality of parts joined along closure seams comprising the steps of: providing a first article part having a container article element region and a first thermally joinable region; providing a second article part by coextrusion through layer forming dies by, providing a plurality of fusible thermoplastic compositions at first locations removed from the layer forming dies, moving the compositions from the first location towards the dies, the movement of at least one of the compositions being accompanied by an agitation thereof, uniformly providing in one of the compositions during its movement toward the die and by means of its agitation, a particulate ferromagnetic oxide susceptor; heating the compositions to a malleable and fusible state during the movement, and forcing the compositions through respective dies into intimate contact with each other while in the malleable and fusible state to form a sheet having joined stratified layers of the compositions coextensive with its dimensions, forming the stratified sheet into a second container article part having a container article element region and a second thermally joinable region contiguous with the article element region, each of said regions containing the susceptor laden layer; juxtapositioning the first and second article parts so that the thermally joinable regions of said first and second article parts are contiguous along a closure seam; applying an alternating magnetic field to the thermally joinable region of said second article part to heat the regions; and bringing the contiguous regions of the first and second article parts into contact to effect thermal joinder between the two to seal the part into the container article.