• Materials for Ceramics

Fillite Standard

Description: Hollow Ceramic Microspheres

Notes

Fillite is a glass hard, inert, hollow silicate sphere. Fillite is primarily used to reduce the weight of plastics, rubbers, resins, cement, etc., but also imparts further benefits in many situations. Many of the advantages from the use of Fillite, including increased filler loading and improved rheology, are directly attributed to the spherical nature of the material.

Characteristics

Lightweight, free-flowing, spherical, inert.

Typical Applications

Refractories, PVC flooring, SBR latex carpet backing, brake linings, Phenolics, Epoxies, Cast Polyesters, synthetic marbles, syntactic foams, BMC, SMC and FRP, low density cements, shotcrete, and wallboard joint compounds, automotive sound-damping sheets.

Advantages

Reduced weight, increased filler loading, better flow characteristics, less shrinkage and warping, improved physical properties in moldings, castings, and laminates, reduced water absorption, improved flame retardance, improved chemical resistance.

Physical Properties:

Average Particle Density 0.6-0.8 g/cc
Average Bulk Density 0.35-0.45 g/cc
Packing Factor 60-65%
Hardness Mohs Scale 5
Average Wall Thickness 5-10% sphere diameter
Melting Temperature: 1220-1350C
Thermal Conductivity: 0.11 Wm-K
Coefficient of Thermal Expansion - 8 x 10 -6 (K)
Surface Moisture 0.3% maximum
Crush Strength: 1500-3000 psi
Oil Absorption: 16-18 g oil/100g

Particle size varies with grades. Varies from 100% minus 100 microns to 20%.

Chemical Properties

Shell is 27-33% Al₂O₃, 55-65% SiO₂, 4% maximum Fe₂O₃. Gas is 70% carbon dioxidate, 30% nitrogen.

Specialty High Alumina grades are also available.

This material does contain trace heavy metals, however they are bound into the glass structure.

Arsenic 10 ppm
Cadmium <0.1 ppm
Cobalt 2 ppm
Chromium 7 ppm
Copper 10 ppm
Mercury 0.5 ppm
Lead 5 ppm
Manganese 10 ppm
Nickel 5 ppm
Zinc 25 ppm
Selenium 0.5 ppm
Antimony n/a

Related Information

Vitreous fired ceramic that stays floating!

The reason this floats is two-fold: It has a low density and it is highly vitreous. This is made from a mix of 60% Plainsman BGP terra cotta clay, 35% Fillite and 5% bentonite (by weight). By volume there is more Fillite than clay. The Fillite reduces the plasticity of the material considerably, but it was still possible to form this ball and the SHAB test bars without problem. This was fired at cone 6, this clay would normally be melting by that temperature. But instead, it acts as a vitreous bonding agent to hold together the millions of tiny glass spheres of the Fillite. The result is a material that does not absorb water easily, this ball floated for more than 8 hours before sinking.

Data

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