BOARDS

摘要

IMPROVEMENTS IN OR RELATING TO BOARDS A board of sandwich construction which comprises two outer preformed support membranes consisting of or comprising fibrous material, the said membranes having interposed therebetween an aerated intermediate layer comprising at least 70% by weight based on the dry board of an unfired clay which contains less than 20% by weight of expandable minerals and the intermediate layer also including fibres therein. The boards of the present invention are intended mainly for use as plasterboard substitute.