Dean Peters

June 17, 2014

6 Min Read
Automated shrink labeling opens new markets for wine
After the shrink labels are dropped onto the stack of four single-serve wine glasses, units move into the shrink tunnel.

With demand increasing for its stacked single-serve wine “glasses,” Stack Wines automated its multipack shrink labeling operations to gain the needed high-volume output.

Don’t look now, but there is an emerging trend afoot in which conveniently packaged wine is finding its way into the consumable consciousness of imbibing sports fans, concert goers, boaters, hotel and resort guests and other outdoor enthusiasts.

This trend has been fed and accelerated by the commercial offering of pre-packaged wine products that offer individual servings in “glasses” (actually food-grade PET), already filled with your favorite varietal and sealed in a sterile and tamper-proof package. There is an emerging market for these beverages in places where disposed or broken glass could cause logistical or safety problems.

Stack Wines of California entered this market in March 2013 with shrink-wrapped packages of four individual servings in pre-filled, un-stemmed glasses. These are sealed and stacked four high into a tower. A shrink-sleeve label is placed around this and processed through a steam tunnel, unitizing the filled glasses into a single unit. The subtle graphics of the shrink-sleeve label help define the brand and attract potential consumers.

At venues in which it would be unsafe or unseemly to be carrying and disposing of real glass containers (not to mention the attendant need for cork screws), pre-filled individual wine servings in recyclable plastic packaging are catching on in a big way. These products may not appeal initially to the wine savants among us, but oenological sophistication doesn’t generally prevail at the venues in which these products will find their greatest demand. The real beneficiaries of these products will be casual wine drinkers who enjoy sipping the occasional glass as they attend a sporting event, work the room at a convention or relax poolside at a resort.

Packaging challenges

The four varietals offered by Stack Wines are Cabernet Sauvignon, Charisma, Chardonnay and Pinot Grigio. Whether a wine savant or casual wine drinker, consumers may not appreciate the labeling and packaging challenges that had to be overcome to enable the mass distribution of single-serving wine.

In the early days, filled and sealed serving glasses from Stack Wines were stacked four high in a tower and hand-sleeved for labeling by a co-packer. To meet growing demand, though, automation was required to stack the cups and apply labels at higher speeds.

There are two steps to the shrink labeling operation. The first is the labeler, which applies shrink sleeves from rolls. The sleeved pack is then passed through a steam tunnel where it shrinks tightly and uniformly around the stack of wine glasses. Having considered the options to automate the shrink labeling operation, Stack Wines decided to purchase equipment from PDC Intl. Corp., a Connecticut-based supplier of packaging machinery that is known as a manufacturer of tamper-evident banders and shrink-sleeve labeling systems. Stack Wines selected PDC’s Model R-250 Evolution shrink labeler and Model KST 55-712 single-zone steam tunnel, through which sleeved stacks are passed and the shrink occurs.

Stack Wines had this equipment installed at Varni Brothers of Modesto, CA, a bottler of 7UP, spring water and other beverages. First, the stemless PET glasses are filled with wine and proprietarily sealed with a peel-back foil lid. The glasses are then automatically stacked four-high and transferred to the shrink labeler, which processes up to 90 stacks per minute.

When demand for Stack Wines reached a certain critical mass, Stack Wines CEO Matt Zimmer realized he “needed a higher level of automation to package and label our product. We used a line-integrator to help us design the high-volume Stack Wines packaging/labeling system, and they steered us toward PDC Intl.’s equipment. It has been working great for us.”

The shrink labeler

The R-250 Evolution shrink labeler, introduced in 2010, was developed jointly by engineering teams from PDC’s U.S. and French facilities. It is primarily mechanical in design, and was engineered for continuous operation in packaging operations that run 24/7.

Recognizing that any shrink labeler that halts the cutting function adds to costly downtime, PDC designed its blade systems to be tough and durable. The company’s robust blade assemblies deliver accurate, clean cuts for months on virtually any sleeving film. Long-lasting blades mean reduced downtimes and longer intervals between replacement. PDC blades last months, in contrast to [some] competitive systems, which use tiny, brittle spinning blades that dull quickly, often in days. All PDC blades are re-sharpenable multiple times.

An Allen-Bradley CompactLogix PLC and touchscreen HMI from Rockwell Automation provide the control platform for the R-250 Evolution line. In addition to its many standard features, R-250 systems can integrate optional modules for vertical and horizontal perforations (important for consumer tamper evidence), date coding and bar code verification. The standard sensor and verification package (which includes material-out and film feed jam sensors, as well as upstream photo-electric sensors) can be enhanced to identify jams downstream, fallen bottles and other anomalies, and provide detailed machine status indication.

Two options designed specifically for continuous production environments are a zero-downtime, splice-on-the-fly accumulator that allows label roll changes without stopping production, and a second unwind reel. Stainless steel construction is available for applications in wet environments. An articulating splice table for quick and precise roll splicing, conveyors and shrink tunnels can also be supplied as part of the R-250 package.

The steam shrink tunnel     

Various types of shrink tunnels are used to shrink sleeve labels around product containers, including infrared, convection and steam. Stack Wines opted for steam because steam tunnels yield the highest quality and most uniform shrinking, with graphics that are precise and distortion-free. The PDC steam tunnel uses proprietary technology and design to apply heat uniformly and with great temperature precision due to its advanced steam control package, while also metering steam for the lowest possible energy use.

The shrink tunnel is made from dual-wall, heavy gauge stainless steel, which allows heat to circulate efficiently, while protecting operators from excess temperatures. There are four rows of steam tubes on each side and each tube is externally adjustable for steam volume, flow and nozzle positioning so that steam can be focused at specific points on the package.

Package enables product

It is not often that packaging and labeling techniques, in and of themselves, enable the creation of a new product, but such is the case with Stack Wines. It’s hard to imagine what form the Stack Wines product would have taken without the confluence of technologies that enabled automated shrink sleeve labeling to create a stack of individual wine servings.

Zimmer says demand for Stack Wines is growing at a solid pace, and the company’s investment in automated packaging/labeling equipment was a timely one.

Dean Peters has been a communications professional since 1992, writing about various aspects of manufacturing.

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