Adhesives Seal-in Summer Fun

Posted on 6/22/2015 8:11:44 AM By Hallie Forcinio

It’s the season for picnics and barbeques. But eating meals and snacks outside can involve more work than fun if foods and beverages aren’t packaged for portability.

For example, securely glued paperboard carriers make it easy to move four, six, eight or event more beverage bottles or cans at a time – a major benefit when a crowd is expected.

Single-serving and portion packs are easy to carry too, especially for condiments and snacks. One popular option—variety packs—allow family members and guests to pick their favorite snack and practice portion control at the same time. Single servings also prevent the waste that occurs when the remaining contents of a multi-serving pack spills, experiences an invasion by ants or goes stale due to exposure to humid air,.

However, adding an easy/open reclose feature to multi-serving packs combat these shelf-life-limiting hazards. One peel/reseal design, Cryovac Multi Seal® FlexLOK™ lidstock from Sealed Air Corp., Elmwood Park, NJ, consists of scored film covered by a pressure-sensitive label with a tab at the center or corner. The lidstock is applied to pre-formed trays or paired with a flexible or formable bottom web. On the finished package, lifting the tab pulls away the scored area and opens the pack. Pressing the label back in place reseals the package.

Another easy-open/reclose option, Low Tack Adhesive (LTA), has been developed by Battelle, Columbus, OH, and Mondelēz International, Deerfield, IL. The adhesive combines high self-adhesion with low tack, meaning it’s not sticky to the touch, but does stick to itself. As a result, it doesn’t pick up crumbs, dust or product fragments, which quickly limits the effectiveness of traditional peelable pressure-sensitive adhesives.

Seven years under development, LTA is designed to replace clips, twist ties, zippers and other reclosure options. It is applied to packaging film using conventional printing and coating technologies and cured with ultraviolet energy. Said to be less expensive and easier to manufacture than other easy-open/reclose options, it is compatible with a variety of manufacturing processes. A 3D version can replace traditional hook-and-loop closures for applications needing higher seal strength. LTA performs through many opening/reclosing cycles and reseals easily since precise alignment is not required.

Although the partners are awaiting word from FDA regarding acceptance of the product for food packaging, it is currently available for non-food applications like tissues, trash bags and wipes. Stu Stein, Director of Open Innovation at Mondelēz International says, “We believe LTA represents the next evolution in reclosable food packaging and can’t wait to see the reaction from consumers when they experience it for the first time.”

Outdoor meals also benefit from moisture-resistant packaging. Here too, adhesives play an important role. In fact, brewers and beverage makers pay special attention to label adhesives to ensure the label stays on the bottle and protects brand identity even when it spends a couple hours chilling in a tub of ice water.

Some water-resistant label adhesives do double duty. Labels with H.B. Fuller’s water-based Fulltak SE 8301 pressure-sensitive adhesive not only withstand two hours of ice water exposure, but also remove cleanly during the caustic wash process for returnable glass bottles. Proprietary polymer technology enables the adhesive to release from the container without dissolving in the wash water and becoming a contaminant.

I think it’s time for a picnic!

Jeff Boyce, LTA
(PHOTO: ASC-BattelleMondelez-Jeff Boyce in Lab with LTA)

A prototype snack bag with an LTA seal reseals just as well the last time as the first time because the adhesive only sticks to itself and doesn’t capture crumbs, dust or product fragments.