Tandem mixers have two intermeshing type mixing units arranged vertically inside a fully enclosed structure, so the rubber compound moves directly from the first stage to the second with very little dust released into the workshop. The upper mixing unit handles the initial blending of the rubber compound and maintains the required temperature during mixing, while the lower unit continues the process with better dispersion and temperature control through optimized ventilation, a larger cooling area, and faster discharge.

The lower mixing unit operates without a ram, and this stage does not require the addition of small chemicals or oil. The rotor seals have an oil-free, anti-fouling design to limit material build-up, reduce contamination of the compound and surrounding area, and extend service life. Both the upper and lower mixing units use on-site online control, which reduces the influence of manual operation and keeps compound quality more stable from batch to batch.

Tandem mixers are suitable for PCR (Passenger Car Radial) and TBR (Truck and Bus Radial) compounds, especially during final mixing. In contrat with tangential internal mixers, tandem mixers can improve compound dispersion by more than 10% and complete the work in a single mixing stage. Completing the mixing process in one stage can increase production efficiency by over 80%, cut power consumption by 30%–50%, and reduce workshop space and equipment investment by 20%–30%.