Zip-Pak has introduced a new closure, the Retort zipper, a design which the company claims is a major leap forward in packaging technology.
The design is said to provide converters and food marketers with resealable zipper technology that withstands the high temperatures required during retort packaging. Resealable, retortable flexible packages have a wide variety of potential applications, including moist pet food, tuna, soup, condiments, and other foods.
"Retort pouches and bags are gaining popularity worldwide, and so is the demand for multi-serve portions," said Robert Hogan, director of sales and marketing for Zip-Pak. "The addition of a resealable feature enhances the convenience that a package provides. Consumers can now protect and store unconsumed portions of a product in its original package - something a can simply can't do. This feature provides brands with a new advantage over the competition."
The retort process exposes filled and sealed packages to high temperatures for a defined period of time.
"The challenge has been to create a zipper that can withstand the high temperatures," Hogan said. "Our Retort zipper has been put to the test and will not degrade or melt during the retort process."
Zip-Pak's retortable zipper is composed of a blend of resins. The company says that preliminary testing has been favourable, showing that it can withstand temperatures of 250°F (121°C) for 30 minutes without losing zipper performance. The strength required for repeated opening and resealing is retained, and the heat seal that bonds the zipper to the packaging film stays permanently intact. Zip-Pak expects this product to be commercial by this summer.
Zip-Pack says the zipper can be sized to different widths and configurations, and runs with ease on most pre-form pouch machines.
Retort flexible packaging offers a number of distinct benefits over traditional retort containers such as aluminum cans. In bags and pouches, food is packed flatter, and heat is distributed more evenly. The same sterility can be obtained over shorter periods of time. This reduction in heat exposure results in better retention of flavours, yet still reduces energy costs, shortens cycle times and increases productivity.
"With the added benefit of resealability, bags and pouches will continue to grow as consumers' preferred option for retort applications," said Hogan.
Zip-Pak is a worldwide leader for resealable packaging technology, with around 200 patented products available for a wide range of flexible packaging applications. World headquarters are located in Illinois, US. Zip-Pak is an Illinois Tool Works (ITW) Company.