Microwavable Packaging

If there's a market that has helped define what packaging-driven "convenience" is all about, it's that of microwave packaging. Consumers simply love the time-saving convenience of microwaveable heat-and-serve foods to put meals on the table.

Once upon a time in the 1990s, this market that was a fundamental part of a drive to dual-ovenable packaging - packaged foods that can be heated in a microwave or conventional oven. PET-coated paperboard and CPET (crystallized polyethylene terephthalate) trays were the dual-ovenable packages of choice.

The market is aligned with microwave oven shipments, which peaked around 2005 when they reached nearly 14 million. Sales have since flattened into a range between approximately 9mn and 9.5mn units, a pace that is forecast to remain static through 2017. This seems to reflect a maintenance level in a market where basically just about everybody has a microwave oven.

One of the technical breakthroughs and on-going market drivers has been the development of various microwave susceptor formats. Susceptors are essentially metallized polyester films that are typically laminated to paperboard or in multilayer film structures and permit browning and crisping of foods by directing the microwaves to the product surface contacted by the susceptor and thus mimic conventional oven heating.

When microwave packaging really had a head of steam for growth back in the 1990s, there was much debate over whether or not these films provided a "functional barrier" to keep the metallized bits from migrating into the food. If that were true, it would cause a serious food safety hazard because aluminum (commonly used in susceptors) was linked to Alzheimer's. Microphotos of cracking and crazing of these films viewed post-heating created quite a stir. However, when the dust cleared, it was determined that, yes, these films provided a barrier and were safe to use and the market dodged a major disruptor to growth.

A recent example of a susceptor-enhanced package is the 2013 AIMCAL Product of the Year for vacuum-packaged microwaveable bacon. The packaging uses QuiltWave susceptor rollstock of polyester (PET)/paper/patterned susceptor-metallized PET. A printed paperboard sleeve provides brand identity and product information, but is removed prior to microwaving. During the one-minute cooking period, the cells created by the pattern in the QuiltWave susceptor inflate to contact the four thin slices of bacon and cook it to the desired crispness.

 

Another major driver the past decade has been the development of film structures for bags that permit controlled seal failure so that the bag automatically ruptures to properly vent the internal steam during the microwave heating cycle. This feature played into the nutritional benefits of steamed cooking vs stovetop boiling. Initially used for bagged vegetables, the technology spread over into ready meals.  Another way to achieve the same result is the application of a pressure-release valve onto a bag panel. This on-going trend combines the ultra-convenience of packaged foods that can simply be placed in the microwave and heated without requirement of consumer-made knife-cut slit or fork-poked holes for venting, all within the popularity of ready meals in a flexible packaging format.

Lastly, one recent news report  indicates consumers may be favoring the toaster oven over the microwave these days, thus ensuring that dual-ovenable packaging may remain as viable as ever.

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