Inorganically filled starch based fiber reinforced composite foam materials for food packaging

Abstract

A process for the manufacture of highly inorganically filled starch based fiber reinforced foam composites for food-packaging use is described. Starch, obtained from potato, corn, or other sources, is used as binder to form net shape foam composite substrates under hydrothermal conditions. The starch content is 25 to 60 wt. % of the product. Ground calcium carbonate is the principal inorganic material, being 25 to 60 wt. % of the product. The composite substrate is foamed by steam at temperatures between 160° and 220°C in a single 15 to 200 seconds step within heated molds. The organic-inorganic composite is reinforced with 5 to 20 wt. % wood or plant fiber. The substrate is rendered functional with food and beverages by thin overlay coatings that provide moisture barrier properties and additional mechanical flexibility.The product is used to package dry and wet foods and meets required food packaging standards. The substrate biodegrades rapidly in the presence of sufficient moisture or microbes. An environmental life-cycle model and an economic model are described as the additional forces to a materials model for research, development and commercialization. The primary goal of this development is to provide disposable packaging materials from renewable resources that are low in cost, low in environmental impact, and meet commercial performance requirements.