Some cooks never needed a burner. They needed the batch to be the heating element. A high-speed rotor-stator mill puts enough energy into a viscous charge that the product temperature rises from the work done in the head: impact, attrition, and viscous dissipation at tip speeds up to 9,000 feet per minute. No hot-oil unit, no steam jacket, no electric mantle on the shell. The heat shows up in the material because that is where the energy was spent.
Kady International has listed this duty for years: heats up to 400°F in 40 minutes with no external heat source. The KADY® mill pumps the batch through radial slots in the rotor and drives it into the staggered slots of a close-clearance stator. Upper and lower propellers keep the vessel turning over, so the temperature rise is not a hot film at the head and a cold heel in the corner. Forty minutes to 400°F is the stated window on a charge that can take that energy. It is not a promise that every solvent letdown will behave the same way.
Send the formula and the temperature you actually need. Call 207.883.4141 or send a RFQ. We will tell you whether the head can carry the cook, or whether the vessel still wants a jacket.
Where the Heat Comes From
External heat crosses a wall. Mechanical heat is generated in the product.
- Impact at the stator. Material leaves the rotor and hits the stator face. A share of that kinetic energy stays in the batch as heat.
- Attrition in the clearance. The close rotor-stator gap works viscous product on every pass. Thicker cooks convert more of that work into temperature.
- Turnover. Propellers above and below the head feed the working zone, so each pass adds heat to the whole charge instead of a recirculating pocket.
- No coil lag. There is no jacket to heat before the batch heats. The rise starts when the head is up to speed and the viscosity is high enough to take the energy.
That is why the duty shows up on resin cooks, fluxing work, and other high-viscosity fluid/solid systems, not on a water-thin blend. A low-viscosity solvent cut sheds energy as flow. A heavy resin, rubber, or polymer charge keeps it.
What the 40-Minute Cook Is For
- Resin and varnish bodies that need temperature to dissolve and build, and that are already viscous enough to self-heat.
- Fluxing and polymer wet-out, where the batch has to reach process temperature before the dispersion is finished.
- Plants with no steam or hot oil at the tank, or no appetite for a second utility on a small cook.
- Short runs where heating a jacket, holding, and cooling the utility takes longer than the batch.
The same mill can be built with a jacket when you need both: mechanical heat on the way up, jacket cooling on the way down, or jacket trim if the formula must not coast past a set point. Self-heating is an option the head already has. It is not a reason to skip temperature indication.
Control Is the Difference Between a Cook and a Scorch
A head that can put a batch at 400°F can also overshoot if nobody is watching viscosity and speed.
- Variable-frequency drive. Tip speed is the heat input. Drop the speed when the temperature is close, instead of riding a fixed sheave.
- Temperature indication in the batch, not only on the shell. The shell can be cooler than the product when the heat is being made inside it.
- Cooled shaft where a long hold at high speed would otherwise cook a bearing or skin the product on the hub.
- Jacket as a brake, on formulas that must level off below the temperature the head could reach.
- Closed cover when the cook releases volatiles on the way to temperature.
Find the curve on your charge. Kady offers free testing. Call 207.883.4141 or start at free testing and bring the resin or polymer, the fill level, and the temperature you cannot pass.
What to Spec With the Mill
- Horsepower and head size matched to batch volume. Underpowered heads stir. They do not cook.
- A vessel rated for the temperature and for whatever pressure the closed cook develops.
- Stainless wetted parts as standard, special alloys when the chemistry requires them.
- Sweep or auxiliary flow once viscosity climbs and the batch stops feeding itself to the rotor.
- A sample point, so body and temperature are read on the product, not assumed from the timer.
From a Lab Heat-Up to the Kettle
The Model L uses the same rotor-stator principle as the production mills, so a self-heat trial on the bench is the same mechanism at scale, not a hot plate standing in for the head. Production follows the mass you have to bring to temperature.
- Lab mills for a heat-up curve on a small charge.
- Top entry mills for batch cooks with no external heat, or with a jacket added.
- Bottom entry mills when discharge of a hot, heavy cook calls for it.
- High-speed production mills for full-scale cooking and dispersion.
- Refurbished mills, rebuilt to factory specs and shipped with a new-machine warranty, when the cook is proven and the utility budget is not.
What to Have Ready Before You Call
- Formula and viscosity at the start of the cook, and how thick it gets at temperature.
- Target temperature, maximum temperature, and whether 400°F is the process or the ceiling.
- Batch size and how many turns per shift.
- Whether the plant has steam or hot oil, or the point is to avoid both.
- Volatiles, pressure, and alloy limits.
Put the Energy in the Batch
KADY® International has designed and built high-speed rotor-stator mills in Scarborough, Maine since 1949. The mills mix, disperse, cook, and homogenize fluid and solid systems, and they are running in more than forty countries.
Talk to sales and engineering about a self-heating cook. Call 207.883.4141, or contact Kady. Ask for a lab trial if you want a heat-up curve before you commit to a mill.
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