LIGHT SANDWICHED GYPSUM WALL BOARD Russian patent published in 2013 - IPC B32B13/00 E04C2/26 

FIELD: process engineering.

SUBSTANCE: invention relates to construction materials. Proposed board comprises inner layer of hardened gypsum with top and bottom surface that feature a definite density. Note here that inner layer of hardened gypsum abuts on top binding layer and bottom binding layer with definite density in dry state. Note also that density of inner layer of hardened gypsum is lower than that in dry state of every top an bottom binding layers. Top and bottom binding layers feature thickness varying from 0.05 mm to 0.18 mm. This board comprises top and bottom wallboards. Note here that top wallboard is secured to top surface of inner layer of hardened gypsum by top binding layer. Note here that bottom wallboard is secured to bottom surface of inner layer of hardened gypsum by bottom binding layer. This board in as-dried state has density of 560 kg/m³ or smaller while inner layer of hardened gypsum had mean hardness of at least 48.9 N defined in compliance with ASTM C473. Invention covers also the versions of board design and method of its production.

EFFECT: higher board hardness and strength of inner layer.

19 cl, 8 tbl, 8 ex