Peel-to-foil trays gain benefits from Surlyn- based film lidding

A new film based on DuPont Surlyn packaging resin used in peel-to-foil trays is designed to benefit both food processors and consumers. The result of this recent development from DuPont is a reduction in material use, improved production performance, an easy-open package and, in some cases, increased shelf life.

DuPont Packaging worked in cooperation with KM Convenience to introduce a film based on Surlyn for packaging systems in a range of U.K. supermarkets, including Marks and Spencer. The project brief was to produce a peelable lid for wrinkle-wall, uncoated aluminum trays, supplied by U.K. producer Ekco Packaging Ltd.

Alternative to PE-coated board
The peelable lid acts as a replacement to the polyethylene-coated board commonly used in such applications. It also means that there is no need for secondary packaging. The wrinkle wall was used for initial development of the lid due to the difficulty in achieving a hermetic seal and clean peel to the uneven edge.

The use of a lower-cost aluminum foil tray, as well as the elimination of the outer-board sleeve and secondary shrink wrap, increases customer friendliness and reduces costs on the processing production line.

Gas-flushed pack
In a further development, Marks and Spencer has launched a new gas-flushed pack range containing basted chicken and poultry joints for oven cooking. Using a peelable lidding based on film using Surlyn, the packs increase shelf life by three days versus traditional packs with board lids and shrink overwrap.

Initial trials on the system were conducted at DuPont facilities in Geneva, Switzerland. This involved selected grades of DuPont Surlyn being extruded to polyester and biax nylon, while mapping out the peel and seal strength needed for the aluminum trays. After finding the optimum Surlyn resin formulation, a combination of top and bottom web heating tools were developed to fine-tune seal performance and packaging line speed.

Following the commercial introduction of peel-to-foil trays with a wrinkle wall, KM Convenience has expanded the concept to include those with a smooth wall. Both KM and Ekco believe that developments in both areas will revolutionize the use of both types of aluminum containers in a range of applications.

DuPont also recognizes that peel-to-foil trays now provide a new growth opportunity for Surlyn, particularly for value-added food products such as marinated beef and poultry products, as well as prepared vegetables.

For more information:
Ekco Packaging Ltd., Asheridge Rd., Chesham, Buckinghamshire HP5 2QE, Tel: 011-44-1494-775221, Fax: 011-44-1494-791961

DuPont Packaging, Tel: 800-4DU-PACK, Website: www.dupont.com/packaging

Edited by Bill Noone
Managing Editor, PackagingNetwork.com
bnoone@packagingnetwork.com