| 摘要 |
FIELD: foundry. ^ SUBSTANCE: composition containing, mass. %: polyvinyl acetate dispersion, 53.2 - 53.34; sodium chloride, 7.7 - 7.8, water also contains as additive petroleum extract in quantity 0.1 - 0.37 mass. %. In second variant of invention composition contains, mass %: polyvinyl acetate dispersion, 61.8 - 61.9; petroleum extract, 0.06 - 0.12 and water, the balance. Use of petroleum extract allows to strengthen green-sand mold, to lower its crumbling and to protect against humidifying. ^ EFFECT: improved properties of casting molds. ^ 2 cl, 2 tbl, 4 ex |
