Pressure dome cap
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 comprises:
(a) a plug seal configured to seal against an inner surface of a finish of a container when the polyester resin closure is mounted onto the finish of the container, the plug seal including,
(i) an annular wall configured to seat against a top surface of a rim of the finish,
(ii) an outer cylindrical wall extending downward from a first edge of the annular wall, wherein the outer cylindrical wall comprises internal threads or a lip configured to engage with the finish,
(iii) an inner cylindrical wall that extends downwardly from a second edge of the annular wall; and
(b) a lower wall that extends from the inner cylindrical wall, the lower wall extending across a diameter of the inner cylindrical wall, the lower wall having a concave upward shape that is configured to change shape in response to pressurized contents within an interior of the container; and
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 the lip is 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 a 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 an amount of interference in the interference fit is about 0.05 mm.
9 . The polyester resin closure of claim 1 , wherein the lower wall further includes at least one ridge configured to control a shape of the lower wall when the lower wall is under pressure from the pressurized contents within the container.
10 . The polyester resin closure of claim 9 , wherein the at least one ridge has a generally cylindrical shape.
11 . The polyester resin closure of claim 1 , wherein the concave upward shape of the lower wall becomes a convex upward shape when pressure is applied by pressurized contents within the interior of the container.
12 . The polyester resin closure of claim 5 , wherein the plug seal is configured to establish a sealing interface with the finish; wherein a width of the sealing interface is configured to bridge defects present in the finish.
13 . The polyester resin closure of claim 12 , wherein the lower wall is configured to increase pressure on a sealing interface between the plug seal and the finish.
14 . The polyester resin closure of claim 1 , further comprising a tamper evidence feature configured to engage with a tamper evidence ledge of the finish.
15 . The polyester resin closure of claim 14 , wherein the tamper evidence feature comprises a folded band.
16 . The polyester resin closure of claim 15 , 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.
17 . The polyester resin closure of claim 16 , wherein the plurality of spaced-apart bridges is configured to break when the polyester resin closure is unthreaded or removed from the finish.
18 . The polyester resin closure of claim 17 , 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.
19 . A method of manufacture comprising thermoforming, injection molding, or compression molding a polyester resin into the polyester resin closure of claim 1 .
20 . A polyester resin closure that comprises:
(a) a plug seal configured to seal against an inner surface of a finish of a container when the polyester resin closure is mounted onto the finish of the container, the plug seal including,
(i) an annular wall configured to seat against a top surface of a rim of the finish,
(ii) an outer cylindrical wall extending downward from a first edge of the annular wall, wherein the outer cylindrical wall comprises internal threads or a lip configured to engage with the finish,
(iii) an inner cylindrical wall that extends downwardly from a second edge of the annular wall; and
(b) a lower wall extending across a bottom of the inner cylindrical wall, the lower wall having a concave upward shape that is configured to change shape in response to pressurized contents within an interior of the container; and
wherein the polyester resin comprises polyethylene terephthalate, polyethylene furandicarboxylate, or a copolymer of polyethylene terephthalate and polyethylene furandicarboxylate,
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 an amount of interference in the interference fit is from 0.02 mm to 0.2 mm.
21 . A polyester resin closure that comprises:
(a) a plug seal configured to seal against an inner surface of a finish of a container when the polyester resin closure is mounted onto the finish of the container, the plug seal including,
(i) an annular wall configured to seat against a top surface of a rim of the finish,
(ii) an outer cylindrical wall extending downward from a first edge of the annular wall, wherein the outer cylindrical wall comprises internal threads or a lip configured to engage with the finish,
(iii) an inner cylindrical wall that extends downwardly from a second edge of the annular wall; and
(b) a lower wall extending across a bottom of the inner cylindrical wall; and
wherein the polyester resin comprises polyethylene terephthalate, polyethylene furandicarboxylate, or a copolymer of polyethylene terephthalate and polyethylene furandicarboxylate,
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 an amount of interference in the interference fit is from 0.02 mm to 0.2 mm.