Fused Resin-coated Ceramic Sand is quite suitable for Shell Molding
Shell mold casting is a casting method that uses thin shell mold to produce castings. The shell casting was invented by German J. Cronin in 1943, first applied in Germany in 1944, and started to be used in other countries after 1947.
Resin-coated sand. Molding sand or core sand whose surface is covered with a layer of solid resin film before molding. There are two film covering processes: the cold method uses ethanol to dissolve the resin, and urotropine is added in the sand mixing process, so that the two are coated on the surface of the sand. The ethanol volatilizes to obtain film coated sand. Heat the sand to a certain temperature, add resin to melt it, stir to coat the resin on the sand surface, add urotropine aqueous solution and lubricant, cool, break and screen to obtain coated sand.
What is Fused Ceramic Sand?
Ceramic Foundry sand, technically as fused ceramic sand for foundry, is made from calcined bauxite which main content is aluminum oxide, processed by melting, blowing, sieving and blending. Ceramic Foundry Sand has excellent properties, including spherical shape, high refractoriness, good crush resistance, inert chemical characteristics, high reclamation yields, etc. Ceramic Foundry Sand has distinguished performance in foundry in compare with silica sand and other popularly used special sands.
Resin Coated Ceramic Foundry Sand is a commonly used foundry material and a method in foundry practices, it produces castings of high precise dimensions, smooth surface, free of blow holes and devoid of casting defects. It is one of the best molding sands for cars, tractors and hydraulic parts. This method is now popularly used in core-making and molding processes in foundry, especially as the well-known “shell molding method”.
The Resin-coated Sand Using Ceramic Sand Has More Advantages
Higher refractoriness, to cast metals with high pouring temperature (cast steel, alloyed cast steel, stainless steel, etc.)
High strength and toughness, to produce more complicated cores with thin sections.
Lower thermal expansion, to avoid expansion defects
Higher reclamation yield, to reduce waste sand disposal, to decline costs.
Excellent flowability, to make complicated cores.
Lower binder consumption, lower gas evolution，lower manufacturing costs
Inert chemical characteristics, applied in any popular alloys，includes Manganese steel.
Taking advantages of Fused Ceramic Sand, people can make high quality resin coated ceramic foundry sand, which has exceptional properties such as high refractoriness, low thermal expansion, easy to shakeout, high strength, and less gas evolution. For particularly complex cores, resin coated ceramic foundry sand has good flow-ability, which can solve the problem of being not fully formed.
The shell process of the ceramic foundry sand is of high production efficiency. The casting dimensional accuracy and the castings finish are exceptional. The used sand is easy to recycle, which greatly reduces the emission of solid wastes. The environmental benefits of this process are also remarkable.