Pin Mill Improves Access for Cleaning

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Both inner and outer discs swing away from the unit for cleaning of a pharmaceutical-grade pin mill from Munson Machinery.

A new pharmaceutical-grade pin mill (i.e., centrifugal impact mill), model CIM-18-S316 from Munson Machinery, grinds friable powders, flakes, and granules into controlled particle sizes ranging from coarse to fine. Unlike conventional pin mills in which the static outer disc is removable but the inner rotating disc is not, the outer and inner discs can swing away from the unit on cantilevered arms, providing full access to both sides of both discs and the mill housing for rapid cleaning and sanitizing.

High-speed rotation of the inner disc creates centrifugal force that accelerates bulk material entering the central inlet of the opposing stationary disc. As material travels from the center to the periphery of the discs at high speed, it passes through a path of five intermeshing rows of precision-machined, rotating and stationary impactor pins, with the desired tight particle size distribution obtained by controlling the rotor speed. Setting the infinitely variable rotor speed between several hundred rpm and 5400 rpm provides the flexibility to use the machine for coarse grinding and de-agglomerating as well as for fine grinding down to 400 mesh.


Constructed of stainless steel, the unit features a sanitary butterfly valve on the air intake, sanitary fittings at the material intake and discharge, and a wash-down-duty motor. Vertical orientation of the mill housing on tubular stainless steel legs results in a smaller footprint than horizontally-oriented units.