Working with gypsum or ceramics? Use our specially heat treated abrasion resistant dispersion head.

Why gypsum and ceramics destroy a standard head

Gypsum, calcined gypsum, alumina, zircon, silica, and other ceramic powders are harder than the pigments a paint mill usually sees. At 9,000 feet per minute, every particle that crosses the rotor-stator gap is an impact event. A stainless head that is fine for ink will open its clearance on this duty. Clearance is the process. Once the gap grows, shear drops, agglomerates survive, and the grind gauge stops moving even though the motor is still pulling amps.

Gypsum compounds also run heavy. Joint compound, board starch slurries, and filler pastes carry a high solids load that settles if the tank is only stirred. Ceramic slips and tape-cast bodies need the same thing from the mixer: break the clusters, hold a uniform solids load, and do it without shedding metal into the batch. A worn head does both kinds of damage. It leaves agglomerates, and it puts head metal into the slip.

What the heat-treated head changes

Kady’s dispersion head is a slotted rotor inside a close-clearance stator. The batch is pumped through the rotor slots and thrown into the staggered stator slots. Impact and attrition do the size reduction. For gypsum and ceramics, that head is supplied in a specially heat-treated, abrasion-resistant construction so the gap stays in spec longer.

• Standard wetted parts are stainless steel. Abrasive duty uses optional materials of construction, including the heat-treated abrasion-resistant head.
• Interchangeable heads bolt onto the shaft, so a lab unit can run a wear-resistant head without a second mill.
• Ceramic powders are ground and dispersed to sub-micron particle size in the same head that wets them.
• The applications list also covers multi-layer electroceramic capacitors and blending polymers with ceramics or pigments.
• Jacketed housings and tanks are available when the slip needs temperature control as well as wear resistance.

See the high-speed production mill overview

Which mill to put the head on

The head is common across the line. The frame follows batch size and whether the slip is a batch or a continuous body.

• Lab mills such as the Model L use interchangeable heads in different materials. A 3/16 to 3/4 gallon batch is enough to prove grind and wear on your gypsum or ceramic slip before scale-up.
• Top-entry mills drop into open tanks. The Model 100T is the large-batch frame, 250 horsepower, 9,000 ft/min, with optional materials of construction for abrasive material.
• Bottom-entry mills hold homogeneity in high-viscosity pastes and slurries, which is the usual state of a gypsum filler or a loaded ceramic body.
• Continuous-flow mills run 3 to 500 gallons per minute when the slip is a standing product, with more work per pass and a 7 Hegman grind on many pigment systems.
• Refurbished mills can be fitted with a wear-resistant head when the duty is known and the budget is a used frame.

Book a free dispersion test and specify the abrasion-resistant head. Send the powder, the solids target, and the vehicle.

Where this duty shows up

• Gypsum joint compounds, board slurries, and filler pastes that sand a standard rotor.
• Ceramic slips and bodies that have to reach sub-micron size without a long media-mill train.
• Multi-layer electroceramic capacitor formulations, where agglomerates become electrical defects.
• Polymer-ceramic and pigment-ceramic blends that need the filler wet, not floating.
• Ceramic metallizing slips and other hard-particle coatings already listed on the Kady applications page.

Kady International builds these mills in Scarborough, Maine. The company has engineered dispersion equipment for almost fifty years, and mills are running in 41 countries.