New applicators bring speed and efficiency to shrink labeling: modifications to existing technologies answer packagers’ needs for flexibility, fast changeover and small footprints
Shrink label applicators are helping an already growing shrink label market segment move into a higher gear. Not only is their labeling speed increasing, but the quick-change parts featured on today’s models also virtually eliminate downtime between runs, and their smaller footprints enable them to be placed into existing spaces with minimal inconvenience.
Early sleeves were hand applied before shrinking, and this technique persisted until recently for smaller orders. But it didn’t take long before automated sleeve placement streamlined the process while cutting labor costs. The powerful shelf impact of a whole-package label with big, brilliant graphics went a long way toward inspiring these technical advancements.
In general, the sleeve applicators available on the market today are much alike in their search for speed and changeover convenience. Differences among them usually involve the primary operation itself, in the handling and cutting of film and the controls that regulate those operations.
Axon Corp., for instance, recently introduced its EZ-100H model applicator, which sleeves smaller items from 12 to 40 millimeters in diameter (like chapsticks and small health care items) horizontally, relieving the problems that come with standing up a smaller, unstable target. The product is inserted into the sleeve, which then rotates as it goes through the heat tunnel to give even shrinkage. Speeds reach 100 containers per minute. PDC International Corp. offers a similar format machine capable of running at up to 300 cpm.
Another similarity among machines being made today is the use of servos to replace mechanical drives. Since the servos provide high-resolution feedback on the positioning of sleeves and products being sleeved, there is more consistent performance over the machine’s life, without constant maintenance or machine tweaking. As a result, manufacturers like B&H Labeling Systems are guaranteeing labeling defect rates of less than 0.05%.
Production speeds are always important to packaging lines, but they become especially important when a new packaging trend is developing. Milk, for years a drab commodity packaging item, took a new direction when Dean’s Milk introduced its milk chug several years ago. The single-serve bottle with its one-handed convenience and bright sleeve graphics caught the attention both of the burgeoning “eat-on-the-go” lunch crowd and the company’s dairy competitors.
PDC, a leading maker of shrink applicators, immediately began working to increase speeds in its equipment to meet the growing need. This fall, at Pack Expo 2004, the company will introduce its R500 series of applicators, designed to reach production speeds of 500 cpm.
Axon Corp.’s EZ300SL reaches speeds of 300 cpm in production settings, while its banding equipment can achieve up to 600 cpm. Equipment with multiple heads can reach even higher speeds.
But these are rated speeds; actual production speeds depend in part on the container being sleeved. A shaped container like a beer bottle is a simple “target” for a sleeve; a straight-sided cylinder like a spray can requires more care and time.
Other factors can also affect line speed, such as the number of operations being performed. ZYI Corp. developed its 400 cpm labeler as two machines in one, able to apply sleeves and neck bands at the same time, reducing its containers-per-minute speed somewhat, but accomplishing two operations at once and thus saving total production time. It saves line space and equipment to boot. The machine is also available with two sleeving heads, which can increase rates to 700 cpm.
Some sleevers are used by packagers of high-volume products, and often on dedicated lines. For these lines, speed is of primary, importance. Other sleeve labelers operate h-t environments where various size containers are being processed and still others are run by contract packagers. In both these latter environments, with shorter runs and a significant number of size changes, efficiency is critical to maximize production time. Changeovers need to be quick yet exact.
Most manufacturers of these machines feature toolless and quick change of size parts. B&H, for example, has color-coded change parts so they can be quickly identified and coordinated to speed up changeover.
KHS takes changeover to the extreme. KHS’s SL 145-30 sleeve labeler can change from a shrink sleeve labeler to a stretch sleeve labeler, giving customers added decorating and/or production flexibility. With a modular design, the system operates at speeds tip to 700 bpm and provides continuous operation with no stopping for reel change.
Films play a part
Paralleling the evolution of labelers has been the development of new films–primarily lower gauge films that can deliver the same graphic appeal at lower cost.
Lower gauge films can affect sleeve handling, however. Less stiffness in the film sleeve means it is less maneuverable and has to be moved into place with more active participation by the machine. Most machine manufacturers, such as ZYI, incorporate forced insertion designs that enable application of lower cost labels with film thickness of as low as 0.035 mm (35 micron).
Machines today are made to handle various films. The PDC R400 for instance, can apply sleeves of polyvinyl chloride (PVC), polyethylene terephthalate gly (PETG) and oriented polystyrene (OPS) interchangeably.
American Fuji Seal Inc., which makes both films for sleeves and the equipment to apply it, takes a systems approach. The company believes the shrink labeling operation should be coordinated to avoid any film/sleever interaction that might give a negative result.
As these machines have increased speeds and developed more sophisticated film handling techniques, they have also reduced their footprint size. This has been a necessity, since many sleeve applicators go into existing filling operations where floor space is at a premium. The Axon EZ300SL requires only 60 x 70 inches of floor space, for instance, while the ZYI 400 series applicator measures 34 x 36 inches.
Roll-and-shrink operations are done by units that are inserted into the production line of standard roll-fed labelers. Where standard roll-fed labels are attached directly to bottles by adhesives at high speeds, roll-and-shrink labels are glued to themselves during application, using newel, UV-cured adhesives, forming a shrink sleeve. The bottles are then put through a heat tunnel for shrinking, much like a traditional shrink-sleeved bottle.
There were high hopes for this process to speed shrink sleeve production when it was first developed, and it has accomplished this. The BH700 Endura[R] System, produced by B&H Labeling Systems, the leading maker of roll-and-shrink units, can reach speeds of 400 cpm. Production efficiency is further enhanced by color-coded quick-change parts that make changeovers quicker, reducing downtime between runs of different-sized bottles.
Today, however, as traditional shrink sleevers are increasing their speeds, that advantage is diminishing. However, roll-and-shrink operations still offer the advantage of lower initial investment, the practicality of turning a roll-fed labeling line into a shrink line as needed and lower material cost achieved by eliminating the need for inventories of pre-seamed sleeves.
Seams created in the roll-and-shrink process may not be as smooth as those in pre-seamed sleeves, but that’s improving.
The bottom line in evaluating today’s shrink label applicators is that there are choices available that meet a variety of needs.
Tomorrow’s sleevers are going to increase capabilities. But like most labelers, these machines are using mature technology. Expect refinements and improvements, not dramatic breakthroughs.
For more information
The following companies helped with the research of this article:
Ameriucan Fuji Seal Inc.
B&H Labeling Systems
PDC International Corp.
Trine Labeling Systems
William Makely is a freelance writer who specializes in packaging topics. Previously, he was the Features Editor for Food & Drug Packaging.
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