A two roll open mill sits between the internal mixer and the shaping line in most rubber plants. Chenxing's single output shaft two roll mixing mill handles the mixing, warm-up, sheeting and mastication work that decides how uniform the next extrusion or moulding step will be. One motor drives a hard-faced gearbox with a single output shaft, then friction ratio gears turn the two rolls at slightly different speeds. The batch is pulled into the nip, squeezed, cut and folded, and each pass makes the compound a little more even. From CXXK-250 laboratory rolls up to the 810 mm production size, the range covers small colour batches, heavy tyre compounds and everything in between. This page walks through the drive layout, roll construction, safety package and the full model table, so a plant engineer can match a machine to an existing rubber and plastics line solution without guessing.
A single output shaft two roll mixing mill is a two roll machine with a single motor and a hard-faced gearbox that feeds both rolls through friction ratio gears. Many mills use separate motors or double output gearboxes; this layout keeps the drive train short, the alignment predictable and the maintenance list short. The operator loads compound onto the nip between the front and back rolls, the friction ratio carries the stock over the front roll, and the material is repeatedly squeezed and folded until the fillers, plasticisers and curatives are evenly distributed.
The Chenxing range is used for rubber mixing, warm-up, sheeting and mastication in tyre plants, hose and belt factories, seal manufacturers and reclaim rubber operations. It also appears in laboratories where small batches are mixed for formulation trials. Because the machine can heat or cool the rolls with water or steam, the operator keeps the stock temperature where the recipe demands it, from a soft mastication stage to a stiff sheeting pass. For plants that already run plastic recycling line planning or compounding stations, the mill becomes the dependable middle step that turns mixed masterbatch into a workable sheet.
The drive starts with one motor. On the CXXK-250 this means 18.5 kW, and on the CXXK-810 the motor reaches 355 kW, but the architecture stays the same: motor, single output shaft hard-faced gearbox, then friction ratio gears to the front and back rolls. The single output shaft arrangement removes one gearbox casing from the machine, cuts the number of coupling faces and gives the maintenance crew fewer seals and bearings to inspect during a shift change.
The rolls are alloy chilled cast iron. Buyers can choose hollow roll cores for general mixing and sheeting, or peripherally drilled cores when precise temperature control matters. Drilled rolls circulate the heating or cooling medium closer to the working surface, so the roll face temperature stays stable even when a thick batch is dumped onto the nip. Roll journals run in plain or roller bearings inside the frame, and the frame carries the roll gap adjustment, the stock guides and the safety devices.
Roll gap adjustment comes in three forms: manual, motorised and hydraulic. Manual adjustment suits smaller mills and occasional set changes; motorised adjustment is a common middle choice for production machines; hydraulic adjustment lets an operator change the nip without leaving the control position, which is useful on the large XKY and XKR models. Roll speed can be fixed or variable frequency, so a warm-up pass can run slower than a final sheeting pass on the same machine. When a plant already has automatic rubber compound dosing equipment feeding the mixer room, the mill can be matched to the same control philosophy.
The single motor single output shaft drive is the feature that most influences long-term running cost. There is one motor to service, one gearbox to keep aligned, and the friction ratio gears simply divide the torque between the two rolls. The front and back rolls turn at a fixed ratio such as 1:1.10 or 1:1.27, which creates the shearing action that works the compound. Operators see the practical result: fewer drive-related stoppages and more predictable sheet thickness.
The safety package is built into the daily routine. An emergency stop button sits within reach of the operator, a chest safety bar stops the rolls when the operator leans over the nip, and a pull-cord switch runs along the machine so anyone nearby can cut the drive instantly. These devices work together with the stock guides, which keep the band of rubber on the roll face instead of letting it creep toward the frame ends.
Roll temperature is controlled by water or steam through the hollow or drilled cores. The batch capacity, roll diameter and working length come from the model table, and the optional stock blender turns the mill into a more self-sufficient mixing station by folding the bank back over the front roll. With a blender fitted, one operator can manage a larger batch, because the compound returns to the nip without manual cutting and folding.
Models are named after the roll diameter in millimetres. CXXK models are the general mixing and sheeting machines, XKY and XKR variants cover the larger production sizes, and the friction ratio column shows how much shear each model applies. The table below carries the full 12-model range with the values used for quotation, foundation drawing and motor selection.
| Model | Roll diameter (mm) | Roll working length (mm) | Front roll linear speed (m/min) | Friction ratio | Batch capacity (kg) | Motor power (kW) | Max nip (mm) | Overall LxWxH (mm) | Weight (t) |
|---|---|---|---|---|---|---|---|---|---|
| CXXK-250 | 250 | 620 | 15.2 | 1:1.10 | 10-15 | 18.5 | 8 | 3220x1500x1290 | 3.8 |
| CXXK-300 | 300 | 760 | 14.5 | 1:1.10 | 14-16 | 22 | 8 | 3570x1400x1350 | 4.5 |
| CXXK-360 | 360 | 900 | 16.26 | 1:1.25 | 15-20 | 30 | 10 | 3920x1650x1725 | 6 |
| CXXK-400 | 400 | 1000 | 18.65 | 1:1.27 | 25-35 | 40 | 10 | 4380x1710x1880 | 8 |
| CXXK-450 | 450 | 1200 | 23.85 | 1:1.27 | 30-50 | 55 | 10 | 5050x1920x1870 | 13 |
| CXXK-550 | 550 | 1530 | 27.18 | 1:1.25 | 50-60 | 110 | 15 | 6040x2100x1625 | 22 |
| CXXK-560 | 560 | 1530 | 27.61 | 1:1.25 | 50-60 | 110 | 15 | 6040x2100x1625 | 22 |
| CXXK-610 | 610 | 1830 | 28.7 | 1:1.25 | 90-120 | 160 | 15 | 6750x3040x1743 | 35 |
| XKY-660 | 660 | 2130 | 32.45 | 1:1.09 | 165 | 185 | 15 | 7040x3620x2080 | 45 |
| XKR-660 | 660 | 2130 | 28.6 | 1:1.24 | 165 | 250 | 15 | 7465x3660x2080 | 45 |
| CXXK-710 | 710 | 2200 | 31.9 | 1:1.09 | 350 | 280 | 15 | 7650x3200x2860 | 50 |
| CXXK-760 | 760 | 2540 | 33.23 | 1:1.09 | 350 | 315 | 15 | 8560x2970x1970 | 58 |
| CXXK-810 | 810 | 2540 | 31.9 | 1:1.09 | 350 | 355 | 15 | 8680x3575x3020 | 68 |
Selection starts with batch capacity. A plant running 25-35 kg colour batches looks at the CXXK-400; a reclaim rubber line feeding 350 kg at a time moves toward the CXXK-710 or CXXK-810. Foundation planning uses the overall dimensions and weight, while the motor power row tells the electrical engineer which breaker and cable size the machine needs. For plants that also operate pelletizing lines fed by sheeted rubber or film washing lines beside the open mill room, the same engineering team can compare the mill footprint against the rest of the line.
The mill appears wherever rubber has to be worked between the mixer and the final shape. In a tyre plant it warms up masterbatch before extrusion and calendering. In a hose and belt factory it sheets compound to a controlled thickness before the strip feed. Downstream extrusion machinery after the open mill accepts the sheeted strip at a steady rate, so the mill speed is matched to the extruder feed requirement. Seal manufacturers use it to keep small batches of EPDM or NBR uniform, and reclaim rubber plants mill crumb with binder until the blend is ready for the next pass.
The range also covers laboratory work. The CXXK-250 with its 10-15 kg batch suits formulation trials, colour matching and student training, while the CXXK-360 and CXXK-400 are common production sizes for seal and gasket plants. Natural rubber, SBR, butyl, EPDM and NBR all pass through the same nip discipline: load, band, cut, fold, repeat until the dispersion test passes. Plastic processors also use open mills for masterbatch and recycled material blending before the two stage recycling machines or agglomerator units for soft scrap after sheeting take over. The same sheeted strip can feed profile extrusion compound preparation on the open mill or sheet extrusion lines warmed by the open mill.
The main options follow the process: a stock blender for larger batches, motorised or hydraulic roll gap adjustment for faster set changes, variable frequency drive for speed control, and water or steam heating cooling circuits matched to the recipe. A rubber compound mixing station layout can be drawn around the mill so the blender, the dosing system and the sheet take-off fit the available floor space.
Chenxing Machinery backs the mill with a one-year warranty, spare parts supply and selection support. Send the compound type, batch size, roll speed target and available floor area, and the engineering team recommends a model plus the options that actually pay back. The full Chenxing machinery catalog for rubber and plastics lines and the rubber mill auxiliary equipment list help a buyer plan the whole mixing room, not just the mill itself. For maintenance, the mill data sheets and drawings are available from the download area.
For a quote, contact Nicole at Chenxing Machinery: email ceo@cxsljx.com, phone or WhatsApp +86 159 5118 7228. Include the rubber type and the batch weight you mix today, and Nicole will route the enquiry to the engineer who has seen that recipe before. You can also send Nicole your compound details for a mill quote directly through the site.
Yes. The CXXK series handles EPDM in seal and gasket production, with the friction ratio and roll temperature adjusted to keep the band stable on the front roll. For continuous EPDM work, drilled roll cores and a stock blender are the recommended options.
It means the gearbox has one motor input and one output shaft, and the friction ratio gears carry the drive from that shaft to both rolls. Compared with double output gearboxes, there is less alignment work and fewer drive components to maintain.
The CXXK-400 takes 25-35 kg and is a common choice for seal and gasket plants. If the batch is usually at the lower end, theCX XK-360 with 15-20 kg capacity can also work, but the CXXK-400 leaves more room for recipe growth.
Yes. Hollow roll cores accept water or steam circulation, and peripherally drilled cores give tighter temperature control for recipes that are sensitive to roll face heat.
Each mill includes an emergency stop button, a chest safety bar and a pull-cord switch. The devices are positioned around the nip so the operator and nearby staff can cut the drive quickly.
It does. Reclaim plants mill crumb with binder and plasticiser on open mills before pelletizing or sheeting, and the larger CXXK-710 and XK-CX810 models suit the heavier batches. The PET bottle washing lines for reclaimed rubber plants and SMF grinding machines for rubber crumb often sit in the same line.
Yes. Roll speed can be fixed or variable frequency, so warm-up and sheeting runs can use different speeds on the same machine.
Roll bearings, friction gears, stock guides and the seals around the roll journals are the practical first set. Chenxing supplies parts against the model number, and the mill data sheets and drawings list the part references.
Chenxing Machinery provides a one-year warranty on the mill, with technical support for installation and commissioning included.
Yes. Send the batch size, roll diameter target and floor dimensions, and the engineering team proposes a mixing room layout with dosing and take-off around the mill.
Chenxing Machinery Co. supplies single output shaft two roll mixing mills for rubber and plastics processors worldwide. For pricing, delivery time and option selection, contact Nicole at ceo@cxsljx.com or +86 159 5118 7228. The team also posts Chenxing mill installation news, and buyers can browse the Chenxing mill workshop background and the open mill FAQ list while preparing the enquiry. For more information about this machine, view more machine details.