Method of securing a closure on a container
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 method of securing a closure on a container, the method comprising:
placing the closure on a container neck of the container;
conveying the container along a conveying direction;
irradiating a portion of a tamper evidence band of the closure with a substantially planar laser beam to engage the portion of the tamper evidence band with the container neck as the container is conveyed along the conveying direction; and
modifying one or more characteristics of a laser emitted by a source using one or more optical devices to provide, alter or redirect the substantially planar laser beam.
2. The method of claim 1 , wherein modifying one or more characteristics of a laser emitted by a source using one or more optical devices comprises directing the laser emitted by the source at a rotating polygonal mirror to spread the laser.
3. The method of claim 2 , wherein modifying one or more characteristics of a laser emitted by a source using one or more optical devices comprises directing the laser emitted by the source at a freeform mirror to spread the laser.
4. The method of claim 1 , further comprising rotating the closure whilst the portion of the tamper evidence band is irradiated by the substantially planar laser beam.
5. The method of claim 4 , further comprising supporting a radial support flange of the container neck and engaging opposite sides of a container body depending from the container neck to both convey the container along the conveying direction and to rotate the container and closure as it is conveyed along the conveying direction.
6. The method of claim 5 , wherein engaging opposite sides of the container body comprises engaging the container body with a pair of conveyers, each conveyor of the pair of conveyers engaging the container body disposed at a different axial location.
7. The method of claim 1 , further comprising reflecting a part of the substantially planar laser beam which travels past the closure back towards the closure with one or more mirrors.
8. The method of claim 7 , further comprising moving the one or more mirrors with the closure along the conveying direction.
9. The method of claim 1 , wherein modifying one or more characteristics of the laser emitted by the source using the one or more optical devices comprises providing the substantially planar laser beam with a substantially planar focal point along the conveying direction with a scanning lens.
10. The method of claim 1 , wherein irradiating the portion of the tamper evidence band with a substantially planar laser beam comprises creating a predetermined temperature differential between an outer surface of the closure and an inner surface thereof.
11. The method of claim 1 , further comprising perforating, slitting or cutting a membrane joining the tamper evidence band to the closure whilst the closure is installed on the container neck, thereby to provide a frangible connection therebetween.
12. The method of claim 1 , wherein irradiating the portion of the tamper evidence band generates a visual indicator.
13. The method of claim 12 , wherein generating the visual indicator comprises changing a color or opacity of the portion of the tamper evidence band.
14. The method of claim 1 , wherein irradiating the portion of the tamper evidence band comprises directing the substantially planar laser beam along part of a circumference of the portion of the tamper evidence band to engage the portion of the tamper evidence band with a flange of the container neck.
15. The method of claim 1 , wherein a power of the substantially planar laser beam is between 10 W and 400 W.
16. The method of claim 1 , wherein a power of the substantially planar laser beam is between 20 W and 350 W.
17. The method of claim 1 , further comprising gradually reducing a power of the substantially planar laser beam as the portion of the tamper evidence band of the closure is irradiated by the substantially planar laser beam.
18. The method of claim 17 , wherein the power of the substantially planar laser beam is gradually reduced from between 400 W and 350 W to between 150 W and 100 W.
19. The method of claim 1 , wherein the substantially planar laser beam irradiates the portion of the tamper evidence band of the closure for less than 2 seconds.
20. The method of claim 1 , wherein the substantially planar laser beam irradiates the portion of the tamper evidence band of the closure for between 0.3 seconds and 0.7 seconds.
21. The method of claim 1 , wherein the substantially planar laser beam irradiates the portion of the tamper evidence band of the closure for between 0.4 seconds and 0.6 seconds.
22. The method of claim 1 , wherein the closure is a plurality of closures, and the container is a plurality of containers, and further comprising:
placing each of the plurality of closures on a container neck of each of the plurality of containers;
conveying each of the plurality of containers along a conveying direction; and
simultaneously irradiating a portion of tamper evidence bands of at least some of the plurality of closures on container necks of at least some of the plurality of containers with the substantially planar laser beam.
23. A method of securing a closure on a container, the method comprising:
placing the closure on a container neck of the container;
conveying the container along a conveying direction; and
irradiating a portion of a tamper evidence band of the closure with a substantially planar laser beam to engage the portion of the tamper evidence band with the container neck as the container is conveyed along the conveying direction;
wherein irradiating the portion of the tamper evidence band generates a visual indicator, and
wherein generating the visual indicator comprises crystallizing the portion of the tamper evidence band.
24. A method of securing a closure on a container, the method comprising:
placing the closure on a container neck of the container;
conveying the container along a conveying direction; and
irradiating a portion of a tamper evidence band of the closure with a substantially planar laser beam to engage the portion of the tamper evidence band with the container neck as the container is conveyed along the conveying direction;
wherein irradiating the portion of the tamper evidence band comprises directing the substantially planar laser beam along part of a circumference of the portion of the tamper evidence band to engage the portion of the tamper evidence band with a flange of the container neck; and
wherein directing the substantially planar laser beam along part of the circumference of the portion of the tamper evidence band causes a free edge of the tamper evidence band to curl inwardly to engage with the flange of the container neck.
25. The method of claim 24 , wherein a mating surface of the tamper evidence band clears the flange when the closure is placed over the container neck, but engages the flange if the closure is removed from the container neck after the tamper evidence band is irradiated by the substantially planar laser beam.
26. A method of securing a closure on a container, the method comprising:
placing the closure on a container neck of the container;
conveying the container and the closure along a conveying direction;
rotating the container and the closure as the container and the closure are conveyed along the conveying direction;
irradiating a portion of a tamper evidence band of the closure with a laser to engage the portion of the tamper evidence band with the container neck as the container and the closure are rotated and conveyed along the conveying direction; and
supporting a radial support flange of the container neck and engaging opposite sides of a container body depending from the container neck to both convey the container along the conveying direction and to rotate the container and closure as it is conveyed along the conveying direction.
27. The method of claim 26 , wherein irradiating the portion of a tamper evidence band comprises irradiating an entire circumference of the tamper evidence band.
28. The method of claim 26 , wherein engaging opposite sides of the container body comprises engaging the container body with a pair of conveyers, each conveyor of the pair of conveyers engaging the container body disposed at a different axial location.