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 system for engaging a closure to a container, the system comprising:
a conveying assembly configured to convey one or more containers along a conveying direction, each container having an associated closure on a container neck of the container, each closure comprising a tamper evidence band; and
a laser assembly operable to irradiate at least a portion of the tamper evidence band of each closure with a substantially planar laser beam to cause the portion of the tamper evidence band to engage with the container neck as the container and the associated closure is conveyed along the conveying direction.
2 . The system of claim 1 , wherein the conveying assembly is configured to rotate each closure and/or each container to cause the substantially planar laser beam to irradiate an entire circumference of the tamper evidence band as the container moves along the conveying assembly.
3 . The system of claim 2 , wherein the portion of the tamper evidence band is a first portion, and wherein the system further comprises a mirror assembly configured to reflect a portion of the substantially planar laser beam onto the tamper evidence band to irradiate a second portion of the tamper evidence band as the substantially planar laser beam irradiates the first portion of the tamper evidence band.
4 . The system of claim 3 , wherein the first portion of the tamper evidence band and the second portion of the tamper evidence band are overlapping.
5 . The system of claim 3 , wherein the first portion of the tamper evidence band and second portion of the tamper evidence band are not overlapping.
6 . The system of claim 3 , wherein the mirror assembly comprises a plurality of concave mirrors, each concave mirror configured to move in the conveying direction with the one or more containers relative to the laser assembly.
7 . The system of claim 3 , wherein the mirror assembly is stationary relative to the laser assembly and comprises a series of alternating peaks and troughs.
8 . The system of claim 7 , wherein the series of alternating peaks and troughs vary in amplitude.
9 . The system of claim 7 , wherein each peak comprises a pair of opposed flanks which are substantially flat or planar.
10 . The system of claim 1 , wherein the laser assembly comprises a laser source configured to emit a substantially linear laser beam and one or more optical devices configured to modify one or more characteristics of the substantially linear laser beam emitted by the laser source.
11 . The system of claim 10 , wherein at least one of the one or more optical devices is a rotating polygonal mirror configured to convert the linear laser beam emitted by the laser source into the substantially planar laser beam.
12 . The system of claim 10 , wherein at least one of the one or more optical devices comprises a freeform mirror or lens for modifying an intensity distribution of the substantially planar laser beam.
13 . The system of claim 12 , wherein the freeform mirror is configured to modify an intensity distribution of the substantially planar laser beam along the conveying direction.
14 . The system of claim 12 , wherein the tamper evidence band comprises a wall extending in a vertical direction substantially orthogonal to the conveying direction, wherein the freeform mirror is configured to vary an intensity distribution of the substantially planar laser beam along the vertical direction of the wall.
15 . The system of claim 12 , wherein the freeform mirror comprises an adjustment mechanism to allow for adjustment of the modified intensity distribution provided by the freeform mirror.
16 . The system of claim 10 , wherein at least one of the one or more optical devices comprises a scanning lens and the system is configured to direct, in use, the substantially planar laser beam through the scanning lens prior to irradiating the closure to provide the substantially planar laser beam with a substantially planar focal point along the conveying direction.
17 . The system of claim 1 , wherein the portion of the closure is a first portion, and the substantially planar laser beam is a first substantially planar laser beam, and further comprising a second laser assembly configured to emit a second substantially planar laser beam to irradiate a second portion of the tamper evidence band.
18 . The system of claim 1 , wherein the conveying assembly comprises a rail for supporting a radial support flange of the container neck and a pair of conveyors engaging opposite sides of a container body depending from the container neck, the pair of conveyors configured to both convey the container along the conveying direction and to rotate the container and closure as it is conveyed along the conveying direction.
19 . The system of claim 18 , wherein a first of the conveyors is spaced further from the rail than a second of the conveyors for engaging opposite sides of the container body at a different axial location.
20 . The system of claim 1 , wherein the substantially planar laser beam is oriented along the conveying direction.
21 . The system of claim 1 , wherein the laser assembly is configured to irradiate portion of the tamper evidence band so as to create a predetermined temperature differential between an outer surface thereof and an inner surface thereof.
22 . The system of claim 1 , further comprising a piercing assembly configured to perforate, slit, or cut a membrane joining the tamper evidence band to the closure whilst it is installed on the container neck, thereby to provide a frangible connection therebetween.
23 . The system of claim 1 , wherein a power of the substantially planar laser beam is between 10 W and 400 W.
24 . The system of claim 1 , wherein a power of the substantially planar laser beam is configured to be gradually reduced as the at least a portion of the tamper evidence band of each closure is irradiated by the substantially planar laser beam.
25 . The system of claim 24 , wherein the power of the substantially planar laser beam is configured to be gradually reduced from 400 W to 100 W.
26 . The system of claim 1 , wherein the substantially planar laser beam is configured to irradiate the at least a portion of the tamper evidence band of each closure for less than 2 seconds.
27 . The system of claim 1 , wherein the substantially planar laser beam is configured to irradiate the at least a portion of the tamper evidence band of each closure for between 0.3 seconds and 0.7 seconds.
28 . The system of claim 1 , wherein the at least a portion of the tamper evidence band of each closure comprises a polyethylene terephthalate (PET) material.
29 . The system of claim 1 , wherein the one or more containers is a plurality of containers, and wherein the laser assembly is operable to simultaneously irradiate at least a portion of the tamper evidence band of each closure on at least some of the plurality of containers with the substantially planar laser beam as the plurality of containers and associated closures are conveyed along the conveying direction.
30 . A system for engaging a closure to a container, the system comprising:
a conveying assembly configured to convey one or more containers along a conveying direction, each container having an associated closure on a container neck of the container, each closure comprising a tamper evidence band; and
a laser assembly operable to irradiate at least a portion of the tamper evidence band of each closure with a laser to cause the portion of the tamper evidence band to engage with the container neck as the container and the associated closure is conveyed along the conveying direction,
wherein the conveying assembly is configured to rotate each closure and/or each container to cause the laser to irradiate an entire circumference of the tamper evidence band as the container moves along the conveying assembly.