Micro-compounding is the mixing or processing of polymer formulations in the melt on a small scale, typically milliliters.
The L/D of a continuous twin screw extruder is mimicked in a batch micro-compounder by the recirculation mixing time, which is controlled by a manual valve.
With this valve, the recirculation can be interrupted to unload the formulation in either a strand or an injection moulder, a film device or a fiber line.
Typical recirculation times are one to three minutes, depending on the ease of dispersive and distributive mixing of the formulation.
[citation needed] Micro-compounding can now produce films, fibers, and test samples (rods, rings, tablets) from mixtures as small as 5 ml in less than ten minutes.