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 in combination with a laser and a container, the molded closure configured to be installed over a container neck of the container for sealingly closing a container neck opening, the molded closure comprising:
a top wall;
a cylindrical skirt depending from the top wall; and
a tamper evidence band connected to the cylindrical skirt,
wherein the tamper evidence band is configured to clear an annular flange of the container as the molded closure is installed over the container neck opening,
wherein the tamper evidence band is formed of a material suitable to be reshaped upon irradiation by a laser, and
wherein the tamper evidence band comprises a first annular portion connected to the cylindrical skirt of the molded closure and a second annular portion depending from the first annular portion, the second annular portion having a radial wall thickness that is less than that of the first annular portion, and
wherein the laser is configured to irradiate the second annular portion to reshape the second annular portion to form an internal lip below the annular flange of the container, without the application of additional external forces, the internal lip having an internal diameter less than an outer diameter of the annular flange, the internal lip configured to engage with the annular flange and retain the tamper evidence band to the container when the closure is first removed from the container.
2 . The molded closure of claim 1 , 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.
3 . The molded closure of claim 1 , 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.
4 . The molded closure of claim 1 , 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.
5 . The molded closure of claim 1 , 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.
6 . The molded closure of claim 1 , 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.
7 . The molded closure of claim 1 , 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.
8 . The molded closure of claim 1 , 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.
9 . The molded closure of claim 1 , wherein the internal lip extends towards the container neck.
10 . The molded closure of claim 1 , wherein the internal lip extends towards the container neck, with a radially inward end of the internal lip being spaced from the container neck.
11 . The molded closure of claim 1 , wherein the tamper evidence band comprises a substantially cylindrical inner surface devoid of engaging features for enabling a flange of the container neck to be received therein in an unencumbered manner.
12 . The molded closure of claim 1 , wherein the tamper evidence band comprises one or more projections protruding from an inner surface of the tamper evidence band, the one or more projections configured to clear the container neck without deformation of the one or more projections when the molded closure is placed thereon, and wherein one or more areas of the tamper evidence band is configured to deform or shrink inwardly when heat is applied thereto to cause the one or more projections to engage with the container neck upon a first removal of the molded closure from the container.
13 . The molded closure of claim 1 , wherein at least a portion of the tamper evidence band is configured to generate a visual indicator when it is reshaped, which is indicative of reshaping.
14 . The molded closure of claim 13 , wherein the visual indicator comprises crystallization of the portion of the tamper evidence band.
15 . The molded closure of claim 13 , wherein the visual indicator comprises a change in color or opacity of the portion of the tamper evidence band.
16 . The molded closure of claim 15 , wherein the portion of the tamper evidence band comprises an additive configured to change color when exposed to a predetermined heat for a predetermined period.
17 . The molded closure of claim 1 , wherein the molded closure comprises polyethylene terephthalate material.
18 . The molded closure of claim 17 , wherein the polyethylene terephthalate material comprises an intrinsic viscosity of less than 0.7.
19 . The molded closure of claim 17 , wherein the polyethylene terephthalate material comprises an intrinsic viscosity of between 0.3 and 0.7.
20 . The molded closure of claim 1 , wherein the tamper evidence band comprises an internal stress.
21 . The molded closure of claim 20 , wherein the tamper evidence band comprises the internal stress prior to being reshaped.
22 . The method of claim 10 , wherein the reshaping of the second annular portion occurs without the application of other external forces.
23 . The molded closure of claim 1 , wherein the molded closure comprises a tether formed at least partially in the first annular portion connecting the tamper evidence band to the cylindrical skirt, and wherein the tamper evidence band is adapted to be reshaped to secure or couple the tamper evidence band to the container neck while allowing articulation of the tether on removal of the molded closure from the container neck via a cutout portion between the tether and the second annular portion.
24 . The molded closure of claim 1 , wherein the tamper evidence band comprises one or more tabs hinged thereto.
25 . The molded closure of claim 1 , wherein the molded closure comprises a multimodal PET material formed of a first PET having a first molecular weight and a second PET having a second molecular weight higher than the first molecular weight.
26 . The molded closure of claim 1 , wherein the molded closure comprises a membrane joining the tamper evidence band to the molded closure, and wherein the membrane is configured to be perforated, slit, or cut to provide a frangible connection between the molded closure and the tamper evidence band.
27 . The molded closure of claim 1 , further comprising a radial step between the first annular portion and the second annular portion.
28 . 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 .
29 . A method of securing the molded closure of claim 1 on the container, the method comprising:
providing the closure having the tamper evidence band, the closure comprising the first annular portion connected to the cylindrical skirt of the molded closure and the second annular portion depending from the first annular portion, the second annular portion having the radial wall thickness that is less than that of the first annular portion;
placing the closure on the container neck of the container; and
irradiating the second annular portion with a laser beam to reshape the second annular portion to engage the second annular portion with the container neck.