Zircon or chromite
sand molds cannot always offer high refractory qualities, sand particle
crushing resistance and low thermal expansion qualities.Ceramsite
sand from Kupper Corporation, a foundry mold/core media that
consists of artificial spherical ceramic particles, is a durable sand that can
alleviate problems encountered with conventional foundry sand.
The ceramic mold/core media has high refractory qualities, making it ideal for
facing sand and cores, especially for heat-resistant applications. This feature
is an extremely effective means for preventing sand burn-in, fused sand and
sand-related casting surface defects.
Due to the abrasion resistance and crushing resistance of the mullite crystal
ceramic structure, the ceramic mold/core media has high durability.
Conventional natural foundry sand, particularly silica sand, has an angular
shape, making it prone to cracks and breaks which appear during compression.
The ceramic mold/core media does not generate fine cracks as easily.
Conventional foundry sand tends to be crushed during use, which creates large
quantities of dust and unusable fine particles, generating industrial waste. In
contrast to this, the ceramic mold/core media is resistant to crushing during
use, maintains its original particle size distribution and generates no dust.
In addition, the high crush resistance of the ceramic mold/core media prevents
sand loss during reclamation.
High permeability (180 cm/s) and flowability (due to spherical shape) allow
uniform shapes to form without applying strong force vibration and permits the
production of normally problematic, complex-structured cores.
The ceramic mold/core media experiences little thermal expansion, which
prevents the generation of defects (veining, core breakage, etc.) normally
caused by expansion. Castings with complex shapes and high dimensional
precision can be produced because molds will not deform due to expansion.
The mold/core media is a ceramic sinter prepared from spherical granules by
high-temperature sintering. The structure is uniform and consists of dense
mullite crystals ([3A1.sub.2][O.sub.3]-[2SiO.sub.2]).
The ceramic mold/core media is applicable to most existing processes such as
green sand casting, chemically bonded sand casting (including shell molding and
coldbox), V-process and lost foam casting.
The ceramic mold/core media can be used in a wide field of applications, from
sole line sand to facing sand. For core use, it is used at 100% composition and
as a mixture with silica sand. Mixing it with conventional foundry sand causes
no problems.
Kupper