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 method of making a closure that mounts onto a finish of a container; the closure comprising at least one layer that comprises:
(a) an annular wall configured to seat against a top surface of a rim of the finish; and
(b) an outer cylindrical wall extending downward from the annular wall;
the method comprising thermoforming a sheet of a polyester resin into the closure.
2 . The method of claim 1 , wherein thermoforming comprises applying the sheet of the polyester resin to a male mold.
3 . The method of claim 2 , wherein the male mold comprises aluminum.
4 . The method of claim 2 , further comprising demolding the closure from the male mold.
5 . The method of claim 2 , wherein thermoforming further comprises applying a vacuum or pressure to motivate the sheet of the polyester resin into the male mold.
6 . The method of claim 5 , wherein the vacuum or pressure is applied at a range of from about 1 bar to about 10 bar.
7 . The method of claim 5 , wherein the vacuum or pressure is applied at about 4 bar.
8 . The method of claim 1 , further comprising cutting the closure from the sheet of polyester resin after the thermoforming.
9 . The method of claim 1 , wherein the closure further comprises a plug seal configured to seal against an inner surface of the finish.
10 . The method of claim 1 , wherein the closure further comprises a tamper evidence feature configured to engage with a tamper evidence ledge of the finish.
11 . The method of claim 1 , wherein the polyester resin comprises polyethylene terephthalate, polyethylene furandicarboxylate, or a copolymer of polyethylene terephthalate and polyethylene furandicarboxylate.
12 . The method of claim 1 , wherein the outer cylindrical wall comprises internal threads configured to engage with the finish.
13 . The method of claim 1 , wherein the closure comprises:
(a) an outer layer that comprises:
(i) an outer layer annular wall; and
(ii) an outer layer outer cylindrical wall that extends downwardly from the outer layer annular wall; and
(b) an inner layer that comprises:
(i) an inner layer annular wall; and
(ii) an inner layer outer cylindrical wall that extends downwardly from the inner layer annular wall.
14 . The method of claim 13 , wherein the outer layer outer cylindrical wall comprises a plurality of knurls.
15 . The method of claim 13 , wherein an inner surface of the inner layer outer cylindrical wall comprises internal threads configured to engage with the finish.
16 . The method of claim 13 , wherein the closure further comprises a tamper evidence feature that comprises a tamper evidence band.
17 . The method of claim 13 , wherein the outer layer comprises a different polyester resin than the inner layer.
18 . The method of claim 13 , wherein the inner layer is thermoformed from a first sheet of polyester resin, and the second layer is thermoformed from a second sheet of polyester resin.
19 . The method of claim 18 , wherein the inner layer and the outer layer are thermoformed using different molds.
20 . The method of claim 18 , further comprising combining the inner layer that is thermoformed from a first sheet of polyester resin and the second layer that is thermoformed from a second sheet of polyester resin.