Flexpack: Slider Bags

Published: May 21, 2010

Rollprint Packaging Products Inc., Addison, IL, has teamed with Pactiv Corp., Lake Forest, IL, to supply Hefty  Slide-Rite slider customers with an improved filling and opening feature for heavier (15-65 lb), bagged products. 

The challenge for slider bags that are bottom-filled is to minimize the fill force against the slider assembly (which is at the receiving end of a product dump), while at the same time making it easy for consumers to open and access the contents.

Up until now, packagers had been lining the entire bag with expensive peel-seal film to provide a fill barrier on one side and an easy-peel seal on the other.

To help drive costs out of the bag and improve performance for both packagers and consumers, Pactiv teamed with Rollprint to come up with an alternative.  The end result is a 1/2-in. wide strip that has replaced several feet of expensive film.  The new alternative saves time, money, and significantly decreases raw material usage. 

Rollprint’s structure is a 2-mil nylon extrusion coated with 2 mils of its proprietary Allegro B peelable sealant.  The nylon side offers good puncture strength and toughness, while the Allegro B side offers easy-opening and visual evidence of a hermetic seal.

For the processor, Allegro B offers an extraordinarily wide sealing window. This enables the material to accommodate most process variations.  (Allegro B is part of Rollprint’s family of sealants, which have been formulated to handle a wide variety of demanding sealing applications.)

In use, the strip is folded in half to create an inverted V.  The outer legs of the inverted V are adhered to opposite sides of the Slide-Rite slider’s seal area.  (The peelable Allegro B side seals to the slider track sidewall; the nylon side is exposed to the product.)

“On the product side, the geometry and performance characteristics of the nylon now can sustain more than 16-pounds per linear inch of force—which is sufficient to
handle the fill weight of heavier products.  On the consumer side, the Allegro B peelable sealant only requires about a pound and a half of force to open, which enables consumers quick and easy access,” says Dave Cameron, engineering supervisor, Pactiv.

Because the easy-peel assembly is now contained within the seal area of the slider assembly, packagers no longer need to line their bags with a peel-seal layer. Eliminating a production step also means less scrap and downtime.

The new structure is suitable for use on a variety of bag structures including multiwall paper, polywoven sacks, laminates, or composite plastic/paper bags.  Product applications include 15-65 pound bags of pet food, kitty litter, birdseed, rock salt, charcoal, rice, and other grains, etc.

“We look forward to working with bag makers, consumer product goods companies, and packagers to help them minimize costs, reduce material usage and improve the customer experience,” Cameron says.