Patent Application
20230182159
The traditional process of can manufacture requires that the can, before or after necking and flanging, be basecoated and / or decorated with coatings on the exterior of the can. (
Necking makes the open end of the can smaller in diameter (see reference numbers 10 and 12 of
For many years industry leaders have discussed trying to find a means to cover a decorated, lubricated, necked, flanged can with another layer of decoration, despite the complex shape and lubrication. This becomes necessary because of manufacturing flaws which sometimes occur in a run of cans. Worse, due to the nature of the production process, problems are often found when the flawed cans have already been palletized in large numbers. For this reason, the can maker would like to re-basecoat the cans, but as discussed since the cans are lubricated, necked and flanged, they can no longer fit onto a standard mandrel.
This problem is known in the industry, but no solution has been found which is both quick and inexpensive.
As a result, the cans must not only be sold for scrap aluminum prices, a substantial loss, but in addition the cans must be depalletized before being scrapped/crushed/bailed. Thus, labor costs are incurred as well.
At the present time, 100% of cans with decoration flaws are scrapped, there is no production facility in the world which has an economical solution to this problem, nor an economical method of re-basecoating. The cans cannot easily be handled due to being necked, they cannot easily be basecoated without allowing coating to enter the necked open end of the can, handling uncured cans results in build ups of coating which not only make a mess but cause flaws in later cans and can eventually even impair the operation of the machinery, and the cans are lubricated during the original necking and the lubricant presents a problem for any hypothetical newly applied re-basecoat.
Thus, this problem has long been known in the industry and yet has no known practical solution until the present invention.
It would be preferable to provide an economical method, machine, and system of re-basecoating cans with decoration defects.
It would be preferable to provide an economical and fast method, machine, and system of coating cans which have already been necked and flanged, for example, cans which have decorating flaws.
It would yet further be preferable to provide a practical and economical method, machine and system for re-basecoating cans repeatedly, so that multiple coats may be applied and darker decorative defects (i.e., designs with darker colors such as black predominating) could be quickly covered with sufficient layers to allow for a lighter shade of base-coating as required for coverage of the decoration.
The present invention teaches a quick, practical and economical method for re-basecoating cans with design defects in basecoat or decoration, despite the cans being necked and flanged. In addition, the present invention teaches a core machine and an overall system for re-basecoating necked, flanged cans with design defects.
The invention teaches that a depalletizer may move the cans from a pallet to an infeed conveyor, where the cans may pass by a corona or plasma treatment which removes the lubricant. Thereafter the cans reach an infeed starwheel which removes the cans from the conveyor and places them into the pockets (and onto the vacuum chucks) of a main starwheel.
The main starwheel may advantageously have a horizontal plane of rotation, as this assists with the re-basecoating process of the invention. In addition, the main starwheel will carry the cans first to a can body coating application device (such as a high durometer resilient roller), then to a can neck coating application device (of a similar material but shaped for the neck/flange of the can). After that, the cans may have a new coating on them, but will still require at least partial curing, so the main starwheel will carry the cans through an induction tunnel before the cans are removed by an outfeed device and placed onto an outfeed conveyor. The curing is necessary to allow handling of the cans.
The main starwheel also has hold down chucks which hold the can from the top (in addition to the vacuum chucks holding the can from the bottom). This is in marked contrast to known coating systems which use a cylindrical mandrel inside of an un-necked, un-flanged, un-lubricated can. The hold down chucks also cover the top of the can so that the new coating material does not enter the can - this was also previously unknown, as in traditional systems the mandrel substantially occupied the volume of the can and so covering it was un-needed.
The main starwheel may convey a given can past the re-basecoating rollers more than once in order to apply multiple coats. Additional sets of coating devices may also be employed.
Spray guns may in alternative embodiments be used in place of rollers, though rollers are presently preferred.
A second curing step may be added: the first curing step in the curing tunnel beside the main starwheel need only cure the outermost layer of new coating material so that the cans can be handled without be smeared, without spreading coating all over the machinery following the coating rollers, and so forth.
The rollers may be shrouded to prevent coating material from flying off during use.
A vacuum plate may be employed as the outfeed device, or an outfeed starwheel.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system for cans which are already necked and decorated, comprising: an infeed conveyor carrying such cans;
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system wherein the main starwheel further comprises: a main starwheel plane of rotation which is horizontal.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system wherein the body coating application is a first roller.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system wherein the neck coating application device is a second roller.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system wherein the outfeed further comprises: an outfeed starwheel.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system wherein the induction tunnel further comprises: a second induction coil.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system wherein the induction coil and the second induction coil induce an electrical current in such can whereby the coating is at least partially cured.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system wherein the body coating application device is a first spray gun.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system wherein the neck coating application device is a second spray gun.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system wherein the outfeed further comprises: an outfeed vacuum plate.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system wherein the main starwheel is operative to rotate such cans more than one time through the body coating application device and the neck coating application, whereby more than one layer of the coating may be applied to such cans.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating system further comprising:
a second body coating application device and a second neck coating application device, whereby more than one layer of the coating may be applied to such cans.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating machine for cans which are already necked and decorated, comprising:
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating method of re-basecoating defectively decorated cans which have already been necked and basecoated, but in which cans the original basecoat has been found to be defective, the method comprising the steps of:
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating method comprising the steps of:
method of re-basecoating defectively basecoated or decorated cans of claim 15, wherein the step of applying at least one new basecoat to the defectively decorated cans is carried out by rolling the basecoat onto the cans.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating method wherein the step of removing lubricant from the necks of the defectively decorated cans is carried out using a plasma spray dimensioned and configured to remove lubricant from such neck of such cans as the infeed conveyor carries such cans.
It is therefore another aspect, advantage, objective and embodiment of the invention, in addition to those discussed previously, to provide a decoration defect re-basecoating method wherein the step of applying at least one new basecoat to the defectively decorated cans is carried out using a coating formulated to adhere to basecoat, ink, and overvarnish.
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a
In the appended claims, the word “such” refers to work pieces which the invention’s claimed limitations and elements operate upon but which are not themselves parts of the claim invention. In particular, “such cans” refers to cans or other open ended cylindrical containers (in further particularity, beverage cans), “such necks of such cans”, “such necks”, etc, refers to the narrower necked portion of such cans, “such body of such cans” and similar terms refers to the relatively straight walls of such cans below the neck.
Cans are not claimed in the appended claims, only the deco defect re-basecoating system of the present invention.
The terms tangent point of the body and tangent point of the neck refers to the place on such cans where the neck and body join at a relative angle.
It will be noticed that the claims refer only to necked cans: prior art relevant to un-necked cans will simply not work on necked cans, except by being retroactively changed according to the learning of the present invention.
The un-necked part 8 is straight, so coating (for example from an unseen spray gun) can be applied easily. The un-necked can 4 can easily be handled on the mandrel and can easily be removed (for example with a puff of air) without disturbing the decoration or the basecoat, since the body side walls are straight.
However, soon after this step the can will be lubricated, necked and flanged, resulting in the shape seen in the necked cans 14 seen in all other
Infeed starwheel 106 then removes the cans from the infeed conveyor 102 and placing the cans 14 on the main starwheel 108 which carries four hold down chucks 114. Vacuum chucks 112 (not visible in
Can covers 116 carried by the hold down chucks 114 serve a dual purpose as the operative portion of the hold down chucks, securing the flanged necks, but also covering the open end of the can to prevent coating from entering during later steps.
Induction tunnel 118 (discussed in greater detail in
Outfeed starwheel 134 then removes the cans 14 from the main starwheel 108 and places them onto the exit conveyor 122. After this step the cans 14 may go to a further curing device or go to another similar machine for another coating, or may be decorated, etc. One advantageous outcome would be repalletizing of the cans 14, now free of deco defects.
The infeed conveyor 102 and outfeed conveyor 122 are much as previously seen, while the infeed starwheel 106 and the outfeed starwheel 134 may be seen in greater detail to have two levels, and different shapes.
In
Sealed, the can 14 passes by body coating application roller 124, and as they mutually roll against one another the entire vertical can body wall is coated up to the tangent point (where the vertical can body wall meets the neck). Cover 138 prevents the rapidly spinning roller 124 from spreading the coating material in all directions. Thereafter the main starwheel 108 carries the can 14, now partially re-basecoated, past the neck application roller 128, which is an entirely different shape from the body application roller 124. Neck application roller 128 is contoured to generally match a can neck shape, and in alternative embodiments may even be contoured to match a specific run of cans. It may also project further toward the can 14 than the body roller, since the neck is relatively speaking recessed. The neck roller 128 and neck 12 may roller against one another until the entire neck is re-basecoated. Neck roller cover 140 serves a function similar to body roller cover 138.
Both rollers may be made of a high durometer resilient material allowing them to conform to the can 14 shape. This is important as the can is NOT internally supported by a mandrel, as previously discussed, unlike the prior art shown in
Outfeed vacuum plate 132′ replaces the outfeed starwheel in this alternative embodiment, by exerting a negative pressure differential against the open end 10 of the can, thus adhering the can to the plate 132′ above. Track 133′ serves to guide the bottom end of the can 14.
Induction tunnel 118 may be seen to have a central semi-circular area through which the can 14 is carried by the starwheel 108. The can 14 thus passes between two induction coils 120 and 136. The electrical current begins the process of curing the new basecoat on the can. As noted previously, it is important to cure at least the outside layer of the new basecoat so that the can may be handled like a normal necked can.
This view also shows in greater detail the vacuum chuck 112 on which the can rides, secured between the vacuum chuck below and the hold down chuck / can cover 114 / 116 above.
Body application spray gun 126′ replaces body roller 124 and obviates the necessity for shroud 138 over the roller 124, while neck spray gun 130′ replaces the neck roller 128 and its shroud 140.
Spray guns are standard in the industry for applying base coats to cans without defects, and even to apply coatings internally. The industry is familiar with their use and maintenance. However, it is an alternative embodiment in the invention for various reasons. Overspray may be a problem for other places than just the can, the spray gun may not coat properly with the desired coating and so on.
Infeed conveyor drive 142 and exit conveyor drive 144 are of course controlled and synchronized with the main starwheel 108 drive (unseen), for example by a digital controller. Note that either drive may in fact also drive the main starwheel 108, for example, drive 144 can easily drive the operations of the main device by means of a power take off from the idler pulley wheel under the outfeed starwheel, however, the preferred embodiment uses three drives, with the main drive inside of the machine body 146.
It will be understood that the step of recoating a can, with basecoat, decoration, ink, etc, will require a basecoat formulated to adhere to basecoat, ink, and overvarnish. This is because at the present time, basecoat, decoration, ink, overvarnish and so forth are formulated to adhere to bare aluminum, not to overvarnish or the like. It is estimated to be 95% likely that standard formulations will not adhere properly when used in the present invention.
The disclosure is provided to render practicable the invention by those skilled in the art without undue experimentation, including the best mode presently contemplated and the presently preferred embodiment. Nothing in this disclosure is to be taken to limit the scope of the invention, which is susceptible to numerous alterations, equivalents and substitutions without departing from the scope and spirit of the invention. The scope of the invention is to be understood from the appended claims.
Methods and components are described herein. However, methods and components similar or equivalent to those described herein can be also used to obtain variations of the present invention. The materials, articles, components, methods, and examples are illustrative only and not intended to be limiting.
Although only a few embodiments have been disclosed in detail above, other embodiments are possible and the inventors intend these to be encompassed within this specification. The specification describes specific examples to accomplish a more general goal that may be accomplished in another way. This disclosure is intended to be exemplary, and the claims are intended to cover any modification or alternative which might be predictable to a person having ordinary skill in the art.
Having illustrated and described the principles of the invention in exemplary embodiments, it should be apparent to those skilled in the art that the described examples are illustrative embodiments and can be modified in arrangement and detail without departing from such principles. Techniques from any of the examples can be incorporated into one or more of any of the other examples. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but reserves all copyright rights whatsoever. 37 CFR 1.71(d). This application is a continuation-in-part of previously filed and co-pending U.S. Application 16/696,990, filed Nov. 26, 2019, which is a continuation-in-part of U.S. Application 15/858,292 filed Dec. 29, 2017 (now patent number 10,518,285) which is itself a continuation of U.S. Application 14/484,229, filed Sep. 11, 2014 (now patent number 9,889,460), for which documents and cases the priority and benefit are hereby claimed. This invention relates generally to can spraying / coating machinery but very specifically to recoating/rebasecoating/decorating/overvarnishing of cans which had previously had decoration defects.
This invention was not made under contract with an agency of the U.S. Government, nor by any agency of the U.S. Government.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15858292 | Dec 2017 | US |
| Child | 16696990 | US | |
| Parent | 14484229 | Sep 2014 | US |
| Child | 15858292 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16696990 | Nov 2019 | US |
| Child | 17838269 | US |
