Developing laminations for the microwave

Emerald Packaging has used both its laser microperforation and hot needle perforation capabilities to create microwave packaging for several industries, including baby carrots, frozen food and fresh potatoes. A few years ago, we developed a package for Wada Farms through our distributor Idaho Packaging that allowed customers to microwave two pounds of potatoes producing a ready-to-eat meal. Our customer selected a laminated structure in order to increase shelf appeal and we suggested hot needle perforation as the best route to allow steam to escape as the potatoes cooked.

With carrots and frozen food we've taken different routes. Emerald Packaging produces a microwave baby carrot package for Grimmway Farms using a three-layer film approved for microwave use that we surface print with heat resistent inks. Since achieving the correct oxygen/carbon dioxide balance is important to maintaining the shelf life of baby carrots, we use laser microperforation for this package. Given the ease of steaming baby carrots as opposed to potatoes, the laser holes are more than big enough to allow for cooking - even though you can't see the holes. We use our laser microperforator for frozen food microwavable packages, usually laminated flexible packages so their graphics stand out in the freezer section. Here, laser holes, or even slits in one layer of film, are preferable in order to prevent the freezer burn that would occur if larger hot needle holes were used.