POLYESTER RESIN CLOSURES FOR CONTAINERS
Thermoformed polyester resin closures for closing containers, the polyester resins including polyethylene terephthalate (“PET”), polyethylene furandicarboxylate (“PEF”), or a copolymer including PET and PEF, are provided herein. Methods of making the thermoformed closures are further provided. Methods of sterilizing the thermoformed closures are further provided.
1 . A polyester resin closure that mounts onto a finish of a container; the polyester resin closure comprising:
(a) a plug seal configured to seal against an inner surface of the finish;
(b) an annular wall configured to seat against a top surface of a rim of the finish;
(c) an outer cylindrical wall extending downward from the annular wall, wherein the outer cylindrical wall comprises:
(i) a plurality of threaded portions that each begin at a corresponding thread start; and
(ii) a plurality of knurled portions distributed circumferentially around the outer cylindrical wall.
2 . The polyester resin closure of claim 1 , wherein the plurality of knurled portions are uniformly distributed around the outer cylindrical wall.
3 . The polyester resin closure of claim 1 , wherein the plurality of knurled portions are axial and extend at least part of the way between the annular wall and a lower portion of the outer cylindrical wall.
4 . The polyester resin closure of claim 1 , wherein the each of the plurality of threaded portions is disposed between each of the plurality of knurled portions.
5 . The polyester resin closure of claim 4 , wherein the plurality of threaded portions is equally distributed around the circumference of the outer cylindrical wall.
6 . The polyester resin closure of claim 1 , further comprising a tamper evidence feature that comprises a plurality of internal knurls disposed about an inner surface of the tamper evidence feature.
7 . The polyester resin closure of claim 6 , wherein the plurality of internal knurls is distributed unevenly about a circumference of the inner surface of the tamper evidence feature.
8 . The polyester resin closure of claim 6 , wherein the tamper evidence feature further comprises a folded band.
9 . The polyester resin closure of claim 8 , wherein the plurality of internal knurls contacts a surface of the folded band when the closure is installed onto the finish.
10 . The polyester resin closure of claim 1 , wherein the polyester resin comprises polyethylene terephthalate, polyethylene furandicarboxylate, or a copolymer of polyethylene terephthalate and polyethylene furandicarboxylate.
11 . The polyester resin closure of claim 1 , wherein the outer cylindrical wall comprises an outer skirt having a clearance with a corresponding outer surface of the rim to enable the polyester resin closure to elastically deform in the region of the plug seal.
12 . The polyester resin closure of claim 1 , wherein the plug seal comprises a chamfer for guiding the plug seal past a lip of the inner surface of the finish when the polyester resin closure is capped onto the container.
13 . The polyester resin closure of claim 1 , wherein the plug seal comprises an inner cylindrical wall that extends downwardly from the annular wall.
14 . The polyester resin closure of claim 13 , wherein the inner cylindrical wall comprises a radial surface that is dimensioned for an interference fit with a corresponding inwardly facing surface of the rim of finish for sealing.
15 . The polyester resin closure of claim 14 , wherein the interference fit is configured to lock the polyester resin closure to the finish.
16 . The polyester resin closure of claim 15 , wherein the amount of interference in the interference fit is from 0.02 mm to 0.2 mm.
17 . The polyester resin closure of claim 15 , wherein the amount of interference in the interference fit is about 0.05 mm.
18 . The polyester resin closure of claim 13 , wherein a lower wall extends across a bottom of the inner cylindrical wall.
19 . The polyester resin closure of claim 18 , wherein the lower wall is configured to change shape in response to pressurized contents within the interior of the container.
20 . The polyester resin closure of claim 19 , wherein the lower wall has a concave upward shape that becomes a convex upward shape when pressure is applied by pressurized contents within the interior of the container.
21 . The polyester resin closure of claim 13 , wherein the plug seal is configured to establish a sealing interface with the finish.
22 . The polyester resin closure of claim 21 , wherein a width of the sealing interface is configured to bridge defects present in the finish.
23 . The polyester resin closure of claim 21 , wherein the lower wall is configured to increase pressure on a sealing interface between the plug seal and the finish.