A self-contained specialty line at American Phoenix
Most production mixing lines are built for volume. Ours are no exception: masterbatch on the Banbury 620s and 440, final mix on a bank of 232-liter Banbury 11D machines, and one 11S reserved entirely for butyl, chlorobutyl, and bromobutyl work. That fleet handles high-tonnage programs efficiently, and it is designed to.
Our 80-liter Banbury tilt-body mixer is built on a different premise. It is not a scaled-down version of our production lines. It is a self-contained specialty line, designed around compounds where process control, changeover discipline, and finishing flexibility matter more than throughput.
What the Machine Is
The mixer is a Kobelco/KSBI 80-liter tilt-body internal mixer, producing approximately 125- to 150-pound batches, depending on the compound’s specific gravity. A 250-horsepower drive and rotor speeds up to 50 RPM give it the torque to work demanding polymers, not only easy-processing formulations.
For scale: our 232-liter production mixers run roughly three times that batch weight. Our 1.5-liter lab mixer runs a small fraction of it. The 80-liter line occupies a genuinely different operating point–production-grade equipment at a batch size that stays practical for specialty and lower-volume programs.
It is well suited to:
• specialty and lower-volume compounds
• color-sensitive materials
• NBR, HNBR, and other technical elastomers
• higher-value compounds that benefit from tighter process control
• programs requiring frequent or deliberate changeovers
• production trials at a meaningful batch size
One Machine, Both Mixing Stages
Our larger lines separate mixing into stages. Masterbatch is mixed on one machine, then transferred to another for the productive pass where the cure package is added. For high-volume work, that division is the right one–each machine does one job and does it fast.
The 80-liter line is configured to handle non-productive and productive mixing in the same body. That has practical consequences. Material does not wait between stages or move between machines. Batch history stays with one set of rotors, one temperature-control system, one recipe. For compounds where the interval between passes affects viscosity, or where every transfer is an opportunity for contamination, keeping the work in one place is an advantage rather than an inefficiency. It also means a single operator team owns the full mixing cycle for that compound, from polymer charge to curative addition to drop.
Building the Sequence Around the Compound
Not every rubber compound should follow the same mixing sequence. The polymer, filler system, oil level, cure package, and processing requirements all affect when ingredients should enter the cycle. The timing of carbon black, oil, polymer, and curatives influences filler dispersion, oil incorporation, final viscosity, and scorch risk.
Some compounds benefit from working the polymer before fillers are introduced. Others process better with an upside-down sequence, where oil and carbon black are charged ahead of the polymer. Specialty elastomers frequently require tighter temperature ceilings to avoid premature cure, which changes both the sequence and the drop criteria.
Recipe control, flexible ingredient charging, and adjustable temperature-control unit (TCU) settings let our team build the cycle around the compound rather than fitting the compound to a fixed cycle. Holding one compound to a tighter temperature limit than the next is a routine setting change, not a line constraint. On a high-volume line, that kind of per-compound tailoring is expensive. On this line, it is the point.
Changeover and Carryover Control
We already segregate one production mixer entirely for butyl work, because some contamination risks are not worth managing–they are worth eliminating. The 80-liter line applies related thinking at a smaller scale. Its tilt-body design opens for direct access to the rotors and chamber, allowing far more thorough cleanout between batches than a fixed-body mixer permits.
That access matters most where carryover is the primary risk: color-sensitive compounds where a trace of the previous batch is immediately visible, specialty formulations with tight compositional specifications, and lower-volume programs that change over often enough for cleanout time to affect the schedule.
A Complete Line, Not a Standalone Mixer
The installation includes a masterbatch cutter and charge scale, skip hoist, two-roll mill, strip-marking system, and carousel batch-off. Material moves through mixing, milling, marking, cooling, and final handling as one connected process.
That completeness is deliberate. Production does not end when a compound leaves the mixer–it has to arrive in a form that works for whatever operation comes next.
Finishing That Fits the Next Operation
Standard slab-dip anti-tack processing works for many downstream applications. It does not work for all of them. Adhesion requirements, product-handling specifications, or the mechanics of the next production step can all mean a compound needs to arrive without dip residue.
So we built an overhead conveyor that bypasses the slab-dip tank and delivers material directly onto poly film. Partners can specify either standard slab-dip finishing or dip-free, poly-interleaved material. The bypass came from partner requests. It reflects how we think about this line generally: the mixing is one half of the job, and delivering material in a usable form is the other.
Why We Built It
The 80-liter line was installed at our Eau Claire, Wisconsin, facility to expand the specialty work we can take on–compounds that need production-grade equipment and process discipline, but not production-scale tonnage.
It runs alongside a fleet built for volume, and it is deliberately different from that fleet. The batch size, the single-machine mixing configuration, the cleanout access, and the finishing options all serve the same purpose: matching the process to the compound and running it to specification.
The equipment is new. The reason for it is not.