초록 ▼

A container or can having a body and end portion which include free ends comprising plastic materials and which are joined and sealed by cooperatively curling juxtapositioned free ends. The method end apparatus of the invention forms the body portion with an opening surrounded by a free end suitable

A container or can having a body and end portion which include free ends comprising plastic materials and which are joined and sealed by cooperatively curling juxtapositioned free ends. The method end apparatus of the invention forms the body portion with an opening surrounded by a free end suitable for curling and forms the end portion with a central portion surrounded by a free end suitable for curling. The container body and end portion are joined by juxtaposing their free ends for forming a plurality of walls, then the plastic in at least one of the free ends is provided in a condition at the time of curling which allows stress and related elastic strain and memory to be imparted to the plastic, followed by curling with a curling tool to intimately engage the ends and concurrently curl the perimeters thereof into a tightly curled configuration, wherein at least the one free end includes internal stress and related strain and memory for providing a seam of integrity and reliability.

대표청구항 ▼

A container comprising: a body having a free end of plastic, and an end portion having a central portion and a free end of plastic about its perimeter, and said free ends being in juxtaposition and continuously flexed to provide a curl to form a plurality of curled walls which are joined together as

A container comprising: a body having a free end of plastic, and an end portion having a central portion and a free end of plastic about its perimeter, and said free ends being in juxtaposition and continuously flexed to provide a curl to form a plurality of curled walls which are joined together as a seam, wherein at least one of said curled free ends includes internal stresses and related strain and memory along its length for providing a seam of integrity and reliability by maintaining engagement therebetween wherein during curling at least one of the free ends are maintained at a temperature below its Vicat softening point. A container comprising: a body having a free end including plastic, an end portion having a central portion and a free end about its perimeter including plastic, and said free ends being tapered, juxtaposed and curled to form a plurality of curled walls which are joined together as a seam, wherein at least one of said curled free ends includes internal stresses and related strain and memory for providing a seam of integrity and reliability by maintaining engagement therebetween. A method of forming a container having a body and an end portion with free ends about their perimeters, wherein the free ends include a plastic and are adapted to be curled, comprising: juxtaposing the free ends, maintaining plastic in at least one of the juxtaposed free ends at a temperature which is below its Vicat Softening Point at the time of curling of the free ends so that at least one of the free ends can develop stress and related elastic strain and elastic memory during curling, and concurrently and circumferentially engaging at least one of the juxtaposed free ends about its perimeter with a die and progressively curving the juxtaposed free ends into a multi-wall curled configuration wherein plastic in at least one free end maintained at a temperature below its Vicat Softening Point during curling develops stress and related strain and elastic memory to thereby produce and maintain engagement therebetween after disengagement between the die and the perimeter of the juxtaposed curled free ends. A method of forming a container having a body and an end portion with free ends about their perimeter, wherein the free ends include a plastic and are adapted to be curled, comprising: juxtaposing the free ends, maintaining plastic in at lest one of the juxtaposed free ends at a temperature which is below its Vicat Softening Point at the time of curling of the free ends so that at least one of the free ends can develop stress and related elastic strain and elastic memory during curling, and concurrently engaging at least one of the juxtaposed free ends about its perimeter with a die and progressively curving the juxtaposed free ends as at least the engaged free end moves along and away from the engaging portion of the die wherein engagement with the die causes the development of stress and related strain and elastic memory in the plastic in at least one of the free ends while said free end is maintained at a temperature below its Vicat Softening Point, whereupon the stress and related strain and elastic memory in at least said one free end urges the free ends to continue to curl into a multi-wall curled configuration as the engaged free end moves away from the die to thereby produce and maintain sealing engagement therebetween. A method of forming a container having a body and an end portion with free ends about their perimeters, wherein the free ends include a plastic and are adapted to be curled, comprising: forming the body having an opening therein and the free end; forming the end portion including a central portion, a wall about the perimeter of the central portion, a free end about the end portion and spaced from the wall portion, and a transitional portion between and connected to the wall and free end forming a recess therebetween, juxtaposing the free ends of the body and end portion to form a plurality of walls therebetween, maintaining plastic in at least one of the juxtaposed free ends at a temperature which is below its Vicat Softening Point at the time of curling of the free ends so that at lest one of the free ends can develop stress and related elastic strain and elastic memory during curling, and concurrently and circumferentially engaging at least one of the juxtaposed free ends about its perimeter with a die and progressively curving the juxtaposed free ends into a multi-wall curled configuration in the recess of the end portion, and wherein plastic in at least the one free end maintained at a temperature below its Vicat Softening Point during curling develops stress and related strain and elastic memory to thereby produce and maintain engagement therebetween after disengagement between the die and the perimeter of the juxtaposed curled free ends.