Multi-web Wonders

Suppliers and converters experiment with film combos to yield more-than-functional flexible packaging.

by Jessica Millward, Associate Editor

Heavy-weight champion

Bearing in mind the enhanced structural demands of commercial packaging, Kapak Corp. has developed a specialty line of retort pouch materials designed for institutional packagers.

Institutional pouches, typically several pounds in weight, must meet barrier, drop test, retort temperature (up to 250°F), and other packaging requirements. The Kapak retort pouch line therefore utilizes a unique film construction: transparent polyester/silica-coated nylon/cast polypropylene on the outside, and a polyester/aluminum foil/biaxially-oriented nylon/cast polypropylene inner layer.

The pouches are manufactured on an eight-color Toshiba gravure press, which provides an extensive drying system for the retort-grade inks used. An Okazaki adhesive laminating system enables converting of specialty films, like the silica-coated nylon, without stress cracking, which would inhibit barrier properties. The film is then cured at 123°F for five days following lamination.

The retort pouches make a beneficial alternative to traditional can containers, offering reduced cooking time; enhanced flavor; larger printing area; and space savings.

Sweet laminates

UCB Films has indulged its sweet tooth with several innovative specialty films intended for use with confections. First up, new release film Propafilm™ RGR02 has been designed for laminate structures common to cold seal applications, and eliminates the need for a release lacquer to be applied to the film. The substrate can be reverse-printed before lamination to a white or metallized film. RGR02 acts as the printed, release-web of the structure, while the laminate partner handles the cold seal adhesive.

Other new members of the UCB repertoire include Propafoil™ RVG, RMC, and RVU films. RVG's high-brilliance factor maximizes shelf appeal, while RMC features a low heat-seal threshold acrylic coating, providing an enhanced oxygen barrier for cookie products. Both of the films can be used in either single- or multi-web configurations. For printers looking to downgauge, RVU is a 15-micron BOPP substrate with higher moisture and oxygen barrier characteristics than thicker metallized films.

Fred Garment, UCB films business manager, specialty packaging films, attests the development of the Propafoil range was spurred on by an ever-increasing demand for metallics in confectionery packaging.

Space-savers

Chuy's Comida Deluxe eateries required a more efficient way of chilling and storing the own-made red and white sauces, whose flavors migrated to each other when stored close together. To conserve storage space, Flexicon Inc., of Cary, IL, engineered a cook-chill system involving multi-web pouches formed from DuPont's Sclairfilm® polyolefin and Dartek® nylon. It replaced Chuy's traditional method using stainless steel pans.

The polyolefin element ascertains the pouch seals can withstand rough handling during stirring of the sauces. Its hot-tack strength also accomplishes reliable seals, preserving the shelf life of the product within. Dartek adds toughness to the packaging, and acts as the flavor/aroma barrier. Additionally, Flexicon's proprietary "cool corners" create a safe area for handling the pouches. Because the pouches are sealed, they can be stacked efficiently and safely, and without fear of cross-contamination of flavors.