METHOD OF MAKING HOLLOW ARTICLES FROM GYPSUM Russian patent published in 2019 - IPC B32B13/00 C04B28/14 B44C5/00 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to molding of articles from binding materials and is intended for its use mainly in production of vases. Method of making hollow articles from gypsum consists in pouring gypsum mixture into a mold in which the mixture is held until it hardens in the mold and the article is formed. Then the item is removed from the mold, peeled, dried and decorated. Mixture of gypsum, wt% – 50–70, water – rest is held in mold for 15–25 minutes until hardening and formation of solid product from mixture. After the article is removed from the mold, the article is cleaned by sandpaper to form roughness on the article surface in intersecting directions. Product is dried in a drying chamber for 18–22 h at air temperature in chamber of 25–55 °C. After drying, product is completely dipped in liquid lacquer in bathroom and held item in lacquer mass for 1–3 minutes until impregnation with lacquer pores in gypsum article, crystallisation of lacquer in pores of gypsum, as well as to moment of gluing lacquer particles with rough surface of article for its retention on surface after extraction of lacquer ware. Then the item is removed from lacquer, lacquer is dried, and after lacquer drying the product is colored and decorated.

EFFECT: high strength of the article and low consumption of material.

3 cl, 1 dwg