Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
130 words
A process of closuring a container which comprises placing a sheet of biaxially orientated thermoplastic resin over the open top of a lipped container so that it overlaps the lip of said container, pushing the overlapping portion of the sheet down with a heated element while clamping the sheet tightly against the container to prevent any heat-softened portions of the sheEt which contact the container from shrinking yet avoiding heat sealing said heat-softened portions to the container, crimping the pushed-down portions underneath and against the lip of the container without shrinking said pushed-down portions and shrinking a portion of the sheet extending across the open top of the container to pull the crimped, pushed-down portions tightly underneath and against the lip of the container after dissipation of said clamping action.
Claim 2
Dependent Claim
130 words
A process of closuring a container which comprises placing a sheet of biaxially orientated thermoplastic resin over the open top of a lipped container so that it overlaps the lip of said container, pushing the overlapping portion of the sheet down with a heated element while clamping the sheet tightly against the container to prevent any heat-softened portions of the sheEt which contact the container from shrinking yet avoiding heat sealing said heat-softened portions to the container, crimping the pushed-down portions underneath and against the lip of the container without shrinking said pushed-down portions and shrinking a portion of the sheet extending across the open top of the container to pull the crimped, pushed-down portions tightly underneath and against the lip of the container after dissipation of said clamping action.
Claim 3
Dependent Claim
15 words
A process according to claim 1 in which the sheet is of biaxially orientated polystyrene.
Claim 4
Dependent Claim
24 words
A process according to claim 1, wherein clamping occurs at a small area of the sheet abutting the upper surface of the container lip.
Claim 5
Dependent Claim
32 words
A process according to claim 1 wherein the sheet is heat-softened at discrete areas spaced around the periphery of the container lip so as to induce the information of evenly spaced pleats.
Claim 6
Dependent Claim
32 words
A process according to claim 1 wherein crimping occurs by moving a sleeve upwardly against the container lip with the pushed-down portion of the sheet interposed between said lip and said sleeve.
Claim 7
Dependent Claim
28 words
A process according to claim 1 wherein the portion of the sheet extending over the open top of the container is shrunk by contact with a heated plate.
Claim 8
Dependent Claim
17 words
A process according to claim 2 wherein the sheet has a thickness between 0.001 and 0.008 inch.
Claim 9
Dependent Claim
44 words
A process according to claim 2 wherein the sheet has a thickness from 0.001 to 0.003 inch, the heated element is at a temperature of from 133* to 137* C. and shrinking is carried out at a temperature of from 128* to 132* C.
Claim 10
Dependent Claim
26 words
A process according to claim 2 in which the time taken to push down the overlapping portions of the sheet is from 0.1 to 0.25 second.
Claim 11
Dependent Claim
32 words
A process according to claim 2 wherein the time interval between pushing down the overlapping portions of the sheet and crimping them against the container lip is from 0.2 to 1 second.
Claim 12
Dependent Claim
36 words
A process according to claim 5 wherein the sleeve is kept in position for a period from 1.5 to 3 seconds during which period shrinking of the portion of the sheet extending across the container occurs.
Claim 13
Dependent Claim
19 words
A process according to claim 5 wherein the temperature of the crimping sleeve is between 10* to 50* C.
Claim 14
Dependent Claim
49 words
A process according to claim 5 wherein a tear strip is placed across the open top of the container prior to sealing the sheet to the container such that said tear strip has an end protruding over the container lip which may be pulled upwardly to open the container.