Stick Packs Open Up

Known for their distinct shape, stick packs offer end-users convenience and portability. Popular for food and nutritional supplements, the format is now being considered for a range of pharmaceuticals. At the pharma event Interphex 2011, Constantia Flexibles showcased a new feature intended to improve stick pack opening.

The materials provider has developed a means to perforate the PET/AL/PE or paper/AL/PE laminate used for stick packs just below the sealing area. The PET or paper in the area of the laser seam is partially removed and the aluminum layer remains intact, thereby ensuring the impermeability of the stick.

“Traditional stick packs can sometimes be difficult to open,” explains Johannes Piesslinger, director of R&D and product management for Constantia Flexibles’s pharma and film division. “They can be hard to tear straight or to fully open, sometimes opening only halfway.” Partially open stick packs can restrict dispensing, resulting in leftover product, he explained to PMP News as he demonstrated opening a stick pack at Interphex.

After struggling to open stick-packaged medicine himself, Piesslinger set out to devise a solution. Piesslinger sought an alternative to “notching the lamination,” calling the process “dirty” because it can generate aluminum particles. In addition, there is a risk that the process can become out of register, he added.

Using existing laser technology used by Constantia for imparting child-resistant features, Piesslinger’s team experimented with different approaches and settled on scoring the laminate during the slitting process. The PET layer is scored without touching the aluminum layer, retaining barrier against moisture, oxygen, and light.

According to Constantia, a predetermined breaking point provides convenient and easy-to-open packaging, and its placement can be customized per user needs. Lines, dots, circles, or other patterns can be created, as can child resistance, with no extra tooling costs.

Because Constantia builds the laser perforation into its own process, pharma companies do not need to modify their own equipment to add the feature.

When compared with sachets, laser-perforated stick packs can lower material use, said Piesslinger. Switching from square sachets could result in a cost savings of up to 40% along with associated costs such as reel storage, worn out parts, and reduced storage.

Constantia Flexibles offers laser-perforating processes out of two of its facilities. For details, visit http://www.constantia-flexibles.com.

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