Closures with tamper evidence
Closures with a tamper evidence feature that is reshaped to connect it to the container neck are disclosed. Methods and systems for carrying out the methods, and to mold stacks for making the closures are also disclosed. The tamper evidence feature can be a band, a portion of a cylindrical skirt or a panel formed in the cylindrical skirt. The application of heat may deform the band inwardly to create a lip for engaging a flange on the container neck, or it may weld the tamper evidence feature to the flange.
1 . A molded closure configured to close a container, the container including a container neck having a flange, the molded closure comprising:
a body formed of a polyethylene terephthalate (PET) material, the body comprising:
a top wall;
a cylindrical skirt depending from the top wall; and
an annular tamper evidence band connected to the cylindrical skirt that is adapted to be reshaped, the annular tamper evidence band comprising a substantially cylindrical mating surface configured to clear the flange of the container neck when the molded closure is placed thereover and is configured to at least partially engage the flange if the molded closure is removed from the container neck after the substantially cylindrical mating surface is reshaped,
wherein at least a portion of the annular tamper evidence band is configured to generate a visual indicator when it is reshaped, which is indicative of reshaping, and
wherein the visual indicator comprises crystallization of the portion of the annular tamper evidence band.
2 . The molded closure of claim 1 , wherein the polyethylene terephthalate material comprises an intrinsic viscosity of less than 0.7 dL/g.
3 . The molded closure of claim 1 , wherein the polyethylene terephthalate material comprises an intrinsic viscosity of between 0.4 dL/g and 0.8 dL/g.
4 . The molded closure of claim 1 , wherein the polyethylene terephthalate material comprises an intrinsic viscosity of between 0.4 dL/g and 0.7 dL/g.
5 . The molded closure of claim 1 , wherein the polyethylene terephthalate material comprises an intrinsic viscosity of between 0.3 dL/g and 0.7 dL/g.
6 . The molded closure of claim 1 , wherein at least a portion of the annular tamper evidence band is configured to generate a visual indicator when it is reshaped, which is indicative of reshaping.
7 . The molded closure of claim 1 , wherein the substantially cylindrical mating surface comprises a reheat agent for increasing a heat absorption of the substantially cylindrical mating surface.
8 . The molded closure of claim 1 , wherein the annular tamper evidence band comprises one or more stiffened portions and one or more weakened portions.
9 . The molded closure of claim 1 , wherein the annular tamper evidence band is adapted to be reshaped upon irradiation by a laser without application of external forces.
10 . The molded closure of claim 1 , wherein the polyethylene terephthalate material comprises an intrinsic viscosity of less than 0.8 dL/g.
11 . The molded closure of claim 1 , wherein the body formed of a multimodal polyethylene terephthalate (PET) material, the multimodal polyethylene terephthalate material formed of a first polyethylene terephthalate material having a first molecular weight and a second polyethylene terephthalate material having a second molecular weight higher than the first molecular weight.
12 . The molded closure of claim 1 , wherein the annular tamper evidence band comprises an annular tamper evidence band wall having a wall thickness in a radial direction and a wall length in an axial direction, wherein the wall thickness is between 10% and 25% of the wall length.
13 . The molded closure of claim 12 , wherein the wall thickness is between 12% and 23% of the wall length.
14 . The molded closure of claim 12 , wherein the wall thickness is between 14% and 21% of the wall length.
15 . The molded closure of claim 12 , wherein the annular tamper evidence band comprises one or more stiffened portions and one or more weakened portions.
16 . The molded closure of claim 1 , wherein the molded closure comprises a membrane joining the annular tamper evidence band to the molded closure.
17 . The molded closure of claim 16 , wherein the membrane is configured to be perforated, slit, or cut to provide a frangible connection between the molded closure and the annular tamper evidence band.
18 . The molded closure of claim 1 , wherein the annular tamper evidence band comprises a first annular portion connected to the cylindrical skirt and a second annular portion depending from the first annular portion, the first and second annular portions each having a radial wall thickness, wherein the radial wall thickness of the second annular portion is less than the radial wall thickness of the first annular portion.
19 . The molded closure of claim 18 , wherein the radial wall thickness of the second annular portion is at least 20% less than the radial wall thickness of the first annular portion.
20 . The molded closure of claim 18 , wherein the radial wall thickness of the second annular portion is between 40% and 90% of the radial wall thickness of the first annular portion.
21 . The molded closure of claim 18 , wherein the radial wall thickness of the second annular portion is between 50% and 80% of the radial wall thickness of the first annular portion.
22 . The molded closure of claim 18 , wherein the first and second annular portions each has an axial height, with the axial height of the second annular portion being at least 50% of the axial height of the first annular portion.
23 . The molded closure of claim 18 , wherein the first and second annular portions each has an axial height, with the axial height of the second annular portion being at least 80% of the axial height of the first annular portion.
24 . The molded closure of claim 18 , wherein the first and second annular portions each has an axial height, with the axial height of the second annular portion being at least equal to the axial height of the first annular portion.
25 . The molded closure of claim 18 , wherein the first and second annular portions each has an axial height, wherein the axial height of the second annular portion is less than 3 times the axial height of the first annular portion.
26 . A molded closure configured to close a container, the container including a container neck having a flange, the molded closure comprising:
a body formed of a polyethylene terephthalate (PET) material, the body comprising:
a top wall;
a cylindrical skirt depending from the top wall; and
an annular tamper evidence band connected to the cylindrical skirt that is adapted to be reshaped, the annular tamper evidence band comprising a substantially cylindrical mating surface configured to clear the flange of the container neck when the molded closure is placed thereover and is configured to at least partially engage the flange if the molded closure is removed from the container neck after the substantially cylindrical mating surface is reshaped,
wherein the annular tamper evidence band comprises an annular tamper evidence band wall having a wall thickness in a radial direction and a wall length in an axial direction, and wherein the wall thickness of the annular tamper evidence band wall has a substantially constant wall thickness of between 0.3 mm and 0.8 mm.
27 . A molded closure configured to close a container, the container including a container neck having a flange, the molded closure comprising:
a body formed of a polyethylene terephthalate (PET) material, the body comprising:
a top wall;
a cylindrical skirt depending from the top wall; and
an annular tamper evidence band connected to the cylindrical skirt that is adapted to be reshaped, the annular tamper evidence band comprising a substantially cylindrical mating surface configured to clear the flange of the container neck when the molded closure is placed thereover and is configured to at least partially engage the flange if the molded closure is removed from the container neck after the substantially cylindrical mating surface is reshaped,
wherein at least a portion of the annular tamper evidence band is configured to generate a visual indicator when it is reshaped, which is indicative of reshaping, and
wherein the visual indicator comprises a change in color or opacity of the portion of the annular tamper evidence band.
28 . The molded closure of claim 27 , wherein the substantially cylindrical mating surface comprises an additive configured to change color when exposed to a predetermined heat for a predetermined time period.
29 . A mold comprising a female cavity piece and a male core piece, the female cavity piece and the male core piece defining a molding cavity configured to form the molded closure of claim 1 .