Retort resistance packaging, also called soft can, is the novel packaging type that have gotten a rapid development in pass two years. It’s a very convenient application for cold dishes and hot cooked food. Long time preservation under room temperature without spoilage is its outstanding features. This packaging is widely applied for food, delicatessen, etc., and it also used in beverages, mashed potato, cereal and so on in Western Europe.

In order to better keep the contents, the common retort resistance packaging in market is adopted high temperature (121℃) sterilization generally, so that can ensure the shelf time in 6 months. With the improvement of people’s living standards, the requirements for food packaging safety are higher and higher. How to effectively extend the shelf life and maximize the flavor and taste of the contents has become a hot focus.

Now many flexible packaging factories usually take the following methods to realize the longer shelf life.

1. Increasing the retort temperature. The contents are further sterilized under the 135℃。
2. Improving the high barrier performance. High barrier is not only reducing the loss of contents flavor, but also can effectively avoid spoilage.

However, with the popularization of microwave ovens, the high barrier & high temperature microwavable packaging has developed rapidly. More convenient and faster cooking methods inevitably require packaging materials to have more functions. Direct heating in microwave oven is not only the function of this kind of high barrier & high temperature packaging material, but also an inevitable development trend.

The traditional barrier materials are PVDC, EVOH, aluminum foil and metalized film. As a high barrier packaging material, PVDC is widely used. But its waste will cause environmental pollution during combustion treatment. The barrier performance of EVOH is seriously restricted by the environment. When the humidity is > 60%, the barrier performance decreases significantly. Aluminum foil is opaque, resource consumption is large, easy to wrinkle and block microwave transmission. The metalized film is difficult to recover, opaque, poor microwave permeability, and easy to peel off when cooking at high temperature.

Based on the above matters, the food processing industry raises higher requirements for packaging materials, the microwavable packaging should have excellent barrier performance, transparency and can be retorted under 135℃.