Abstract

A method for producing food packagings from biodegradable foam material, in particular trays for use as disposable plates or dishes, is described. This involves providing a starting material that consists of or contains an organic cellulose ester or mixed cellulose ester, in particular cellulose acetate, and subjecting the starting material to a pretreatment to reduce the moisture content. By the beginning of the subsequent melting process, the moisture content is kept to, or below, a fixed limit. The pretreated starting material is melted and subsequently made to expand to obtain a foam material of a flat form. This is then followed by the foam material obtained being stored, to allow a second foaming agent to diffuse into it, and heated, in order to bring about renewed expansion. The heated foam material is thermoformed to form the food packaging.

IPC Classes  ?

• C08J 9/04 - Working-up of macromolecular substances to porous or cellular articles or materialsAfter-treatment thereof using blowing gases generated by a previously added blowing agent
• C08J 9/08 - Working-up of macromolecular substances to porous or cellular articles or materialsAfter-treatment thereof using blowing gases generated by a previously added blowing agent by a chemical blowing agent developing carbon dioxide
• C08J 9/12 - Working-up of macromolecular substances to porous or cellular articles or materialsAfter-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
• C08J 9/14 - Working-up of macromolecular substances to porous or cellular articles or materialsAfter-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent organic
• B29C 44/26 - Shaping by internal pressure generated in the material, e.g. swelling or foaming for articles of indefinite length using several expanding steps
• B29C 51/08 - Deep-drawing or matched-mould forming, i.e. using mechanical means only