SU865478A1 - Composition for making moulds and cores by dynamic compacting technique - Google Patents

Description

(54) MIXTURE FOR MANUFACTURING CASTING FORMS OBTAINED BY DYNAMIC METHOD Sand-clay molding compounds are known that contain surfactants, such as organic viscosity reducer (PFLK) or carbon alkaline reagent (UShR). Closest to the proposed technical essence and the achieved result is a mixture containing a refractory filler, clay, ground coal, surfactant (PVLC), a wood-chemical phenolic viscosity reducer, which is methanesulfonated novolak with the following ratio of ingredients, %: Refractory filler Basis Clay. 10.0-12.0 Ground coal - 0.01-5.0. SEALS PFLH0,1-2,0 Water3,0-3,5 h. Known mixtures possess good fluidity, but do not provide fully high deformation properties, which would ensure good compactibility and formability of the mixture. The purpose of the invention is to improve the quality of the forms by increasing its moldability. The goal is achieved by combining, including clay or bentonite, ground stone COAL, a surface-active substance and a refractory filler, as a surfactant 15% aqueous solution of polyox in the following ratio of ingredients, wt.%: Clay or bentonite 7.0-15.0 Ground coal. 2.0-6, 0 15% aqueous solution of polyox 2.5-4.5 Refractory Filler Other Polyox refers to the group of high molecular weight polymers of ethylene oxide and has the properties of reducing the viscosity and preserving its characteristics during heating and dynamic effects.

Lower bentonite content (less than 7 wt.%) Leads to insufficient strength, and elevated (more than 15 wt.% Leads to increased water content, which is undesirable.

Coal is introduced as an anti-additive. Content of it

in small quantities does not give the desired effect, and the high content leads to an increase in gas defects in ingots, including burns. The content of polyox in an aqueous solution 5 was chosen on the basis of the conditions of its best solubility in water.

Tables 1 and 2 show the compositions and properties of the mixtures, which were compacted by Q on a shaking-and-molding molding.

stand

Table 1

Refractory filler (quartz sand 88.5. The implementation of the invention will improve the uniformity of the mold density over the flask height, which will improve the quality of the molds made by shaking, high-speed pulsing, etc.

82.5 74.5 83.8

Claims (3)

Table 2 60 Formula of the Invention A mixture for the manufacture of casting molds, obtained by the method of dynamic compaction, including clay or 65bentonite, ground coal. surfactant and refractory filler, characterized in that, in order to improve the quality of fordiness, the mixture as a surfactant contains a 15% aqueous solution of polyox by the following ratio of ingredients, wt.%: Clay or bentonite 7.0-15.0 Ground coal 2.0-6-6.0 15% aqueous solution of polyoxa 2.5-4 / 5 Ogneu pore filler Else Information sources, accepted & about attention. upon examination 1. USSR author's certificate 486846, cl. B 22 C 1/02, 1974.. 2. USSR author's certificate  546422, cl. a 22 C 1/02, 1974. 3. USSR author's certificate  302164, class In 22 C 1/00, 1967.