New printing process, desiccating film also win in flexibles

Winning silver awards for technical innovation in the Flexible Packaging Achievement Awards are a 360-deg printing process for shrink film, a film

January 29, 2014

11 Min Read
New printing process, desiccating film also win in flexibles

Winning silver awards for technical innovation in the

Printing shrink-pack film 'in the round'


Taking the conventional shrink bag to new technological dimensions, Curwood wins again with a new way to print clear shrink film 360 deg that can make even the most everyday food products look uncommonly eye-catching. Introduced in October, 2003, the Clear-Tite® Surround™ shrink bag with an EZ Peel® opening feature grabbed a silver award in technical innovation for the patent-pending Surround printing process.

Curwood explains that traditional shrink bags are printed on one side of a film tube that is then flipped back through the press and printed on the back side. This provides a two-side-printed, finished package. But the tube of shrink film can't be printed on the sides, due to the fold in the tube. The Clear-Tite Surround printing process resolves this issue. The tube of film is instead slit open, allowing the substrate to be surface-flexo-printed as a flat film in up to nine colors (with overlacquer). Printing the film flat in one pass instead of two eliminates extra printing and handling steps, Curwood explains.

The printed film is then fabricated off-line into a Surround seamed bag. Thus, designs for both the front and back of the package can be printed in one pass across the web.

Curwood says the one-side-printing process is an industry first in the shrink-bag market. The package incorporates Curwood's Surround seven-layer film coextrusion, designed to enhance product performance on packing equipment and extend shelf life and product protection in shipment.

Curwood's patent-pending seven-layer EZ Peel opening feature for shrink bags is also built into this package, in addition to the film formulation's peel characteristics. The convenience feature eliminates the need for a scissors or knife to open the package.

The EZ Peel is similar to the Surround Print process, as the tube is slit open and fabricated into the back seam of the bag During bagmaking, an easy-open pull flap is created so consumers can lift the flap and easily break the hermetic seal. The pack can be pulled apart along the bottom seal.

Curwood's New London, WI, facility produces the Surround base material, converting and back-seaming it on proprietary equipment that Curwood says was engineered internally.

Curwood's Centerville, IA, facility flexo-prints the material in up to eight colors and makes it into bags. Initial applications include chunk cheese and sausage stick packages that John Hackinson, vp of marketing, says cannot be identified as of presstime. However, he points out that various products can benefit from the technology, such as beef jerky, deli logs, holiday hams and turkeys and summer sausage.

More information is available:

Awards Program: Flexible Packaging Assn., 410/694-0800.

. Surround-printed shrink bag: Curwood Inc., 920/303/7300.

Desiccating sealant film
148899-0304fpaex2.jpg A film pouch with a built-in desiccating agent earned Pechiney Plastic Packaging silver award status in the technical category for notable barrier properties that can extend the shelf life of the test strip it contains by several years.

Also a winner in the 2003 DuPont Awards competition (see PD, Sept. '03, p. 80), the single-use pouch was created for Johnson & Johnson's Lifescan Company, Milpitas, CA, for its patented Harmony single-use diagnostic test strips. The test strips are administered by patients or healthcare professionals to test blood coagulation. The pouch has enhanced moisture barriers in a tear-open, flexible format.

This innovative package incorporates a desiccating agent in the sealant film and lamination. The reverse-printed PET and foil extrusion lamination absorbs moisture in the package headspace and protects the contents from moisture that could enter through possible fractures or pinholes.

The barrier lamination is just more than 4.25 mils thick, with a 2.5-mil-thick desiccating sealant film. The structure, from the outside, is a 48-ga reverse-printed PET/white LDPE/ethylene acrylic acid (EAA) coextrusion lamination/foil/LDPE/EAA coextrusion lamination/Pechiney's patent-pending desiccating sealant.

The pouch is a single-use, high-barrier tear-open structure. The desiccating agent is incorporated into the PE sealant film, such that the moisture-barrier property is exponentially increased over traditional foil laminations. As a result, the test strips individually wrapped in the Pechiney pouch provide product protection compared to the HDPE bottles being replaced, at a drastically reduced cost. The technology took about a year to develop.

Lifescan needed an innovative approach for packaging the diagnostic test strips. Conventional foil laminations didn't guarantee the long shelf life Lifescan was after, and the company wanted a flexible structure with enhanced moisture barriers that could still fit within its budget.

Lifescan presently packages diagnostic test strips in a high-density polyethylene bottle that includes a twist cap that incorporates a molecular sieve desiccant into the cap. The bottle contains five diagnostic test strips and is marketed to patients and healthcare professionals for measurement of Prothrombin (PT) in whole blood. The diagnostic test strips are sensitive to exposure to humidity. As long as the bottle is resealed quickly after removal of a diagnostic test strip, the packaging is an effective, albeit expensive, packaging solution. However, the potential exists that an end-user will inadvertently forget to replace the bottle cap, which may result in spoilage of the test strip.

The concept of a single-use package in a high-barrier tear-open flexible pouch was considered to be an attractive option. However, the desire for long shelf life of multiple years could not be guaranteed with conventional foil laminations based upon WVTR calculations. An enhanced moisture-barrier option was required for a much higher degree of product protection, but in a cost-effective flexible pouch. To achieve this, a desiccating agent was incorporated into the polyethylene sealant film such that the moisture-barrier property was exponentially increased over traditional foil laminations. As a result, the test strips individually wrapped in the Pechiney pouch provide the proper product protection at a significantly reduced cost versus the bottle.

Standard four side-seal pouching equipment, Model 4SS, supplied by Doyen Medipharm, was utilized for conversion of the Pechiney desiccating lamination. The desiccating heat-sealable film demonstrated enhanced barrier properties for extended shelf life based upon accelerated stability testing using desiccant sealant. Individual tear-open packages eliminate the risk of contamination presently possible with current bottle configuration, while the slit-style tear notch provides easy opening. The packages are flexo line- and screen-printed with fine-font type.

The degree of innovation is extensive due to the complexity of handling and manufacturing a desiccating moisture-absorbing polyethylene sealant film including the complexities in laminating a film that is sensitive to even ambient humidity. The patent-pending heat-sealable film is FDA approved for direct food contact and substan-tially extends the shelf life of highly moisture-sensitive products. It has the potential to extend beyond pharmaceuticals and medical device packaging into food and electronics packaging where enhanced moisture barrier is required and the elimination of a desiccant sachet may be of value.

More information is available:

Awards Program: Flexible Packaging Assn., 410/694-0800.

Desiccating sealant film: Pechiney Plastic Packaging, Inc., 773-399-8000.

New generation of nonforming web
148402-0304fpaex3.jpg A silver award winner in technical innovation, Cryovac Food Packaging Div.'s Cryovacw NewGen Non-Forming Web was designed for thermoformed packages that replace traditional trap-printed laminate structures with a fully coextruded base material printed using a proprietary surface-printing system. Cryovac says this change in laminate technology delivers a coextruded material with properties mimicking adhesive-laminate films made with an oriented printing substrate. Some applications currently using the NewGen Non-Forming Web include value-added meats, smoked and processed meats, specialty cheeses and snacks such as jerky and beef sticks.

The material can improve customer leadtimes because it can be manufactured in a single pass without time-consuming adhesive-laminating steps, Cryovac says. While conventional printed laminates are usually made by first printing an oriented substrate and adhesive laminating the substrate to a sealant, the NewGen Non-Forming Web is produced first?using nylon, EVOH and a coextruded structure?and is then surface-printed via a flexo process that relies on an overprint varnish to provide protection, gloss and abuse-resistance for printed labeling on top-web lidstocks.

The varnish cures using electron-beam technology, which toughens the "abuse" layer over the ink. The resulting film structure can be produced in thicknesses between 3 and 5 mils. Cryovac is working with multiple customers on developing packaging with NewGen, such as vertically integrated meat processor Emmpak Foods, Marysville, CA, which is using the material for a marinated beef brisket product.

More information is available:

Awards Program:Flexible Packaging Assn., 410/694-0800.

Nonforming web: Cryovac Div., Sealed Air Corp., 800/845-3456.

Peelable coex for surgical gowns
151461-0304fpaex4.jpg Improving the packaging for sterile surgical gowns is the HDPE-Allegrow T easy-peel formed pouch with a peelable coextruded polyester sealant. The easy-peel structure, from Rollprint Packaging, ensures a hermetical seal upon opening. When peeled, Allegro T splits cohesively, leaving a bright white seal indicator so that end-users in the medical field can quickly and easily see if the sterility has been compromised.

Adopted by Rohrdorf, Germany's Sengewald Klinikprodukte for the Secu-Drapew line of sterile surgical gowns, drapes and covers, the sturdy film structure won a silver award in the technical category. Sengewald Klinkprodukte packs the surgical products in Rohrdorf, Germany for European distribution.

Packaging consists of 3.75-mil coextruded, thermoformable base web of nylon/PE and a 3.7-mil coex top web having two layers of white HDPE and a thin coex sealing layer incorporating the proprietary AllegroT easy-peel sealant technology. The four-side-sealed pack replaces a structure with an extrusion-coated paper/PE top web and a nylon/peelable coex sealant base web.

Surface-printed by flexo in two colors, the new pouch structure moves the peel layer from the bottom web to the top web, which Rollprint says radically improves manufacturing efficiencies and cuts the number of converting steps needed. This can also cut material costs.

The blown coex material is surface-printed by flexo by Pactiv/Kobusch/Sengewald, in Warburg, Germany, the same location that also makes the film, Rollprint's Karen Berger tells PD. The printed, slit, finished rolls are then sent to Sengewald Klinikprodukte in Rhordorf, where the packages are made and filled on Multivac equipment.

"The Allegro T sealant differs from many paper-based medical packages that, when torn, can occasionally emit loose fibers into a sterile operating fields (increasing the likelihood of contamination). Because the new structure featuring HDPE-AllegroT is an all-polymer pack-age, fiber presence is not an issue," Berger reports.

The coextruded blend of the Allegro T sealant, which PD has covered in other applications (see PD, Sept. '03, p. 68 and 80), is engineered to produce smooth, consistent peel strength over a very heat-sealing window of 50 deg F.

The Sengewald package represents the first use of the Allegro T peelable sealant technology within a one-step manufacturing process. While the previous materials were purchased on the outside, and made in several processes, the new technology allows the company to have its packaging supplier produce both webs in a single step, according to Rollprint, saving time, money and materials. The pouches are sterilized via gamma radiation. The durable package resists yellowing, eliminates fiber tear issues, offers improved strength properties and has smooth, consistent peel strength.

More information is available:

Awards Program: Flexible Packaging Assn., 410/694-0800.

Peelable pouch: Rollprint Packaging Products, 630/628-1700.

Environmental wrap 'flowers' for plants
152399-0304fpaex5.jpg The result of Highland Supply Corp.'s (HSC) commitment to the environment, a decorative outer wrap for potted flowers and plants won a silver award for environmental achievement. The package is printed using environmentally safe water-based inks that reduce harmful volatile organic compounds (VOCs) and hazardous air pollutant (HAP) emissions and eliminate hazardous process waste.

HSC's water-based inks contain less than 0.70 percent VOCs by weight. After thorough research, the company elected to develop an in-house water-based ink system and says it has developed ways to recycle its water-based inks in-house by reformulating excess inks into useful ones.

The ink costs less than solvent-based inks, since water-based inks have a much higher solids content, resulting in less ink usage per printed area.

More information is available:

Awards Program: Flexible Packaging Assn., 410/694-0800.

Floral overwrap: Highland Supply Corp., 618/654-2161.

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