Consumables

Swedish Company Adopts DuPontT Delrin Acetal Grade for Food Closures

Tuesday 22. October 2013 - Metal Detectable' Attribute Helps Keep Food Safe

Swedish company WeLoc – Weland M. AB taps DuPontT Delrin acetal resin for use in a new range of food-industry bag closures for its suitability for ‘snap-closure’ action, durability at -50°C and this particular grade’s ability to be seen by metal detectors.
These features, combined with the excellent creep resistance, strength, stiffness, toughness, low wear and low friction, offer WeLoc and other food industry suppliers an engineering polymer capable of replacing metal components in a huge array of applications.
Metal or X-ray detection is required in the food industry to protect against foreign material cross contaminating food. This is one of two new food-compliant Delrin resins developed specifically for food processing equipment components; material handling equipment, such as conveyor chains and hoppers; food-manipulation tools, such as cutters, shovels, scrapers; and forms and molds.  Particles as small as 3mm, the size of 3 sugar grains, can typically be detected using standard inspection systems. This helps ensure contaminated food doesn’t reach the consumer.
“We tested other materials for this application but chose Delrin as it fulfilled a number of our major requirements – use down to -50°C, fully metal detectable and FDA/EU(GMP) compliant,” said Arne Henningsson, division manager at WeLoc. “The material also maintains its properties well, has a good resistance against moisture and is pre-colored in the right shade of blue for the food industry.”
The WeLoc closure, originally developed in 1983 for the liquid-tight sealing, has grown to include more than 50 variants in multiple sizes, for the sealing and reclosing of flexible packages across a great many industries and, indeed, in the home as well. They are sold all over the world, under the names WeLoc, CLIP-it and Klippit.
“We strive to produce and supply high-quality products, putting high demands on our partners for development, testing and documentation,” said Henningsson. “DuPont has been a main supplier of the materials for our products since we started almost 30 years ago and we still view them as an important and beneficial partner today and for the future.”
Looking at the wider food processing industry, Delrin offers many potential savings, for example in conveyors, including: cost and maintenance savings based on improved design and functional integration; reduced energy consumption due to lighter components; and longer replacement intervals based on excellent wear/friction properties.
Delrin typically does not require additional lubrication, resulting in silent and durable mechanisms, and offers good, clean aesthetics, leading to a cleaner and friendlier working environment. It also is highly resistant to cleaning agents and offers very good behavior under thermal shock. It also promotes ergonomic improvements thanks to lighter equipment and quieter systems due to lower noise emissions compared to metal equivalents.
“DuPont was involved from the very start of the project and supplied very good support,” Henningsson concludes, “which is not a surprise to us as we already have a good collaborative relationship spanning nearly 30 years. Together with DuPont we are looking forward to develop new materials for our existing assortment and for future products.”
WeLoc also has evolved the design of the bag closure by incorporating other value-added features, including grippers for heavy-duty applications, scoops and spoon for the bag contents (animal feed, coffee, flour, etc.) and indented jaws for holding cables.
WeLoc has 30 years of experience in design and manufacturing of plastic sealers for flexible packaging. The first model was originally developed to seal liquid tight on a special plastic bag in a medical test device. Today it has more than 50 models to seal packaging from small thin plastic bags to big sacks and FIB