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 polyester resin closure that mounts onto a finish of a container; the polyester resin closure comprising:
(a) at least one layer that comprises:
(i) an annular wall configured to seat against a top surface of a rim of the finish; and
(ii) an outer cylindrical wall extending downward from the annular wall, wherein an outer layer outer cylindrical wall comprises a plurality of knurls;
(b) a tamper evidence feature configured to engage with a tamper evidence ledge of the finish;
the method comprising:
injection molding or compression molding the polyester resin into the polyester resin closure; and
combining polyethylene terephthalate with an amount of furandicarboxylic acid (FDCA), diethylene glycol (DEG), or a combination thereof prior to the injection molding or the compression molding to reduce a modulus of the polyester resin and allow the polyester resin closure to be ejected from a cavity of a mold.
2 . The method of claim 1 , wherein the polyester resin comprises polyethylene terephthalate, polyethylene furandicarboxylate, or a copolymer thereof.
3 . The method of claim 2 , wherein the polyester resin is a polyethylene terephthalate copolymer.
4 . The method of claim 3 , further comprising incorporating a co-monomer into the polyethylene terephthalate copolymer to control crystallization and reduce melt processing temperatures.
5 . The method of claim 3 , wherein the polyethylene terephthalate copolymer is PETF.
6 . The method of claim 1 , wherein the modulus of the polyester resin is from 1 GPa to 3 GPa.
7 . The method of claim 1 , wherein the injection molding or the compression molding is performed with a movable core component.
8 . The method of claim 1 , wherein the outer cylindrical wall comprises internal threads configured to engage with the finish.
9 . The method of claim 1 , wherein the at least one layer of the polyester resin 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.
10 . The method of claim 9 , wherein the outer layer outer cylindrical wall comprises a plurality of knurls.
11 . The method of claim 9 , wherein an inner surface of the inner layer outer cylindrical wall comprises internal threads configured to engage with the finish.
12 . The method of claim 9 , wherein the tamper evidence feature comprises a tamper evidence band.
13 . The method of claim 9 , wherein the outer layer comprises a different polyester resin than the inner layer.
14 . The method of claim 1 , wherein the polyester resin closure is transparent.
15 . A method of making a polyester resin closure that mounts onto a finish of a container; the polyester resin closure comprising:
(a) at least one layer that comprises:
(i) an annular wall configured to seat against a top surface of a rim of the finish; and
(ii) an outer cylindrical wall extending downward from the annular wall, wherein an outer layer outer cylindrical wall comprises a plurality of knurls;
(b) a tamper evidence feature configured to engage with a tamper evidence ledge of the finish;
the method comprising injection molding or compression molding polyester resin, which was synthesized while limiting a duration of solid-state polymerization, into the polyester resin closure, thereby resulting in the method being performed while limiting an intrinsic viscosity of the polyester resin.
16 . The method of claim 15 , wherein the limiting of the intrinsic viscosity comprises limiting the duration of solid-state polymerization of the polyester resin after the injection molding or the compression molding.
17 . The method of claim 15 , wherein the polyester resin comprises polyethylene terephthalate, polyethylene furandicarboxylate, or a copolymer thereof.
18 . The method of claim 17 , wherein the polyester resin is a polyethylene terephthalate copolymer.
19 . The method of claim 18 , further comprising incorporating a co-monomer into the polyethylene terephthalate copolymer to control crystallization and reduce melt processing temperatures.
20 . The method of claim 18 , wherein the polyethylene terephthalate copolymer is PETF.
21 . The method of claim 15 , wherein a modulus of the polyester resin is from 1 GPa to 3 GPa.
22 . The method of claim 15 , wherein the injection molding or the compression molding is performed with a movable core component.
23 . The method of claim 15 , wherein the outer cylindrical wall comprises internal threads configured to engage with the finish.
24 . The method of claim 15 , wherein the at least one layer of the polyester resin 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.
25 . The method of claim 24 , wherein the outer layer outer cylindrical wall comprises a plurality of knurls.
26 . The method of claim 24 , wherein an inner surface of the inner layer outer cylindrical wall comprises internal threads configured to engage with the finish.
27 . The method of claim 24 , wherein the tamper evidence feature comprises a tamper evidence band.
28 . The method of claim 24 , wherein the outer layer comprises a different polyester resin than the inner layer.
29 . The method of claim 15 , wherein the polyester resin closure is transparent.
30 . A method of making a polyester resin closure that mounts onto a finish of a container; the polyester resin closure comprising:
(c) at least one layer that comprises:
(i) an annular wall configured to seat against a top surface of a rim of the finish; and
(ii) an outer cylindrical wall extending downward from the annular wall, wherein an outer layer outer cylindrical wall comprises a plurality of knurls;
(d) a tamper evidence feature configured to engage with a tamper evidence ledge of the finish;
the method comprising:
injection molding or compression molding the polyester resin into the polyester resin closure,
wherein the method is performed while limiting an intrinsic viscosity of the polyester resin, and
wherein the intrinsic viscosity of from 0.4 dE/g to 0.7 dL/g.
31 . The method of claim 30 , wherein the polyester resin comprises polyethylene terephthalate, polyethylene furandicarboxylate, or a copolymer thereof.
32 . The method of claim 31 , wherein the polyester resin is a polyethylene terephthalate copolymer.
33 . The method of claim 32 , further comprising incorporating a co-monomer into the polyethylene terephthalate copolymer to control crystallization and reduce melt processing temperatures.
34 . The method of claim 32 , wherein the polyethylene terephthalate copolymer is PETF.
35 . The method of claim 30 , wherein the modulus of the polyester resin is from 1 GPa to 3 GPa.
36 . The method of claim 30 , wherein the injection molding or the compression molding is performed with a movable core component.
37 . The method of claim 30 , wherein the outer cylindrical wall comprises internal threads configured to engage with the finish.
38 . The method of claim 30 , wherein the at least one layer of the polyester resin 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.
39 . The method of claim 38 , wherein the outer layer outer cylindrical wall comprises a plurality of knurls.
40 . The method of claim 38 , wherein an inner surface of the inner layer outer cylindrical wall comprises internal threads configured to engage with the finish.
41 . The method of claim 38 , wherein the tamper evidence feature comprises a tamper evidence band.
42 . The method of claim 38 , wherein the outer layer comprises a different polyester resin than the inner layer.
43 . The method of claim 30 , wherein the polyester resin closure is transparent.