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) an outer layer that comprises:
(i) an outer layer annular wall;
(ii) an outer layer outer cylindrical wall extending downward from the outer layer annular wall, wherein the outer layer outer cylindrical wall comprises internal threads configured to engage with the finish;
(iii) an outer layer inner depression wall that extends downwardly from the outer layer annular wall; and
(iv) an outer layer lower wall that extends across a bottom of the outer layer inner depression wall;
(b) an inner layer that comprises:
(i) a plug seal configured to seal against an inner surface of the finish;
(ii) an inner layer annular wall configured to seat against a top surface of a rim of the finish;
(iii) an inner layer outer cylindrical wall extending downward from the inner layer annular wall, wherein the inner layer outer cylindrical wall comprises internal threads configured to engage with the finish;
(iv) an inner layer inner depression wall that extends downwardly from the inner layer annular wall; and
(v) an inner layer lower wall that extends across a bottom of the inner layer inner depression wall; and
(c) a tamper evidence feature configured to engage with a tamper evidence ledge of the finish;
wherein the polyester resin comprises polyethylene terephthalate, polyethylene furandicarboxylate, or a copolymer of polyethylene terephthalate and polyethylene furandicarboxylate.
2 . The polyester resin closure of claim 1 , wherein the internal threads are configured for a snap-on engagement with the finish.
3 . 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 deform in the region of the plug seal.
4 . 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.
5 . The polyester resin closure of claim 1 , wherein the plug seal comprises an inner cylindrical wall that extends downwardly from the annular wall.
6 . The polyester resin closure of claim 5 , 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.
7 . The polyester resin closure of claim 6 , wherein the interference fit is configured to lock the polyester resin closure to the finish.
8 . The polyester resin closure of claim 7 , wherein the amount of interference in the interference fit is from 0.02 mm to 0.2 mm.
9 . The polyester resin closure of claim 7 , wherein the amount of interference in the interference fit is about 0.05 mm.
10 . The polyester resin closure of claim 5 , wherein a lower wall extends across a bottom of the inner cylindrical wall.
11 . The polyester resin closure of claim 10 , wherein the lower wall is configured to change shape in response to pressurized contents within the interior of the container.
12 . The polyester resin closure of claim 11 , 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.
13 . The polyester resin closure of claim 5 , wherein the plug seal is configured to establish a sealing interface with the finish.
14 . The polyester resin closure of claim 13 , wherein a width of the sealing interface is configured to bridge defects present in the finish.
15 . The polyester resin closure of claim 13 , wherein the lower wall is configured to increase pressure on a sealing interface between the plug seal and the finish.
16 . The polyester resin closure of claim 1 , wherein the tamper evidence feature comprises a folded band.
17 . The polyester resin closure of claim 16 , wherein the tamper evidence feature comprises a plurality of spaced-apart bridges that connect the folded band to the outer cylindrical wall of the polyester resin closure.
18 . The polyester resin closure of claim 17 , wherein the plurality of spaced-apart bridges is configured to break when the polyester resin closure is unthreaded from the finish.
19 . The polyester resin closure of claim 18 , wherein the folded band is configured to be retained in position by the tamper evidence ledge when the polyester resin closure is unthreaded from the finish.
20 . 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 internal threads configured to engage with the finish; and
(d) a tamper evidence feature configured to engage with a tamper evidence ledge of the finish;
wherein the polyester resin comprises polyethylene terephthalate, polyethylene furandicarboxylate, or a copolymer of polyethylene terephthalate and polyethylene furandicarboxylate;
wherein the plug seal comprises an inner cylindrical wall that extends downwardly from the annular wall;
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;
wherein the interference fit is configured to lock the polyester resin closure to the finish; and
wherein the amount of interference in the interference fit is from 0.02 mm to 0.2 mm.
21 . 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 internal threads configured to engage with the finish; and
(d) a tamper evidence feature configured to engage with a tamper evidence ledge of the finish;
wherein the polyester resin comprises polyethylene terephthalate, polyethylene furandicarboxylate, or a copolymer of polyethylene terephthalate and polyethylene furandicarboxylate;
wherein the plug seal comprises an inner cylindrical wall that extends downwardly from the annular wall;
wherein a lower wall extends across a bottom of the inner cylindrical wall;
wherein the lower wall is configured to change shape in response to pressurized contents within the interior of the container; and
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.