DIELECTRIC HEATING OF FOAMED COMPOSITIONS Russian patent published in 2022 - IPC C08J9/32 C08J3/28 B32B5/18 D21H27/30 C09J131/04 

FIELD: packaging.

SUBSTANCE: present invention relates to a method for foaming a composition, including: (a) obtaining a composition containing (i) water-based polymer selected from a group consisting of starch, vinyl acetate-ethylene dispersion, polyvinyl acetate, polyvinyl acetate-polyvinyl alcohol, polyvinyl acetate stabilized with dextrin, polyvinyl acetate copolymers, vinyl acetate-ethylene copolymers and mixtures thereof, (ii) from 0.1 wt.% to 70 wt.% of a set of expandable microspheres characterized by a temperature range of an initial expansion from 80°C to 110°C and a temperature range of a maximum expansion from 50°C to 150°C; and (iii) an additive selected from a group consisting of plasticizers, adhesive additives, humidifiers, accelerators, fillers, pigments, dyes, stabilizers, rheological modifiers, polyvinyl alcohols, preservatives and mixtures thereof; (b) applying such a composition to cellulose substrate, and (c) exposing the composition to dielectric heating for less than 1 minute of the stage (b); as a result, the set of expandable microspheres in the composition expands. In particular, high-frequency (HF) heating is used to heat the foamed composition in order to obtain insulation in the manufacture of products.

EFFECT: invention provides for the production of environmentally and economically balanced packaging, which ensures the presence of uniform thermal insulation for various sizes of packages.

15 cl, 4 tbl, 12 dwg