A pin mill is a

mill Mill may refer to: Science and technology * * Mill (grinding) * Milling (machining) * Millwork * Textile mill * Steel mill, a factory for the manufacture of steel * List of types of mill * Mill, the arithmetic unit of the Analytical Engine early ...

that comminutes materials by the action of

pins A pin is a device used for fastening objects or material together. Pin or PIN may also refer to: Computers and technology * Personal identification number (PIN), to access a secured system ** PIN pad, a PIN entry device * PIN, a former Dutch de ...

that repeatedly move past each other. Much like a kitchen

blender A blender (sometimes called a mixer or liquidiser in British English) is a kitchen appliance, kitchen and laboratory appliance used to mix, crush, purée or emulsion, emulsify food and other substances. A stationary blender consists of a blender ...

, it breaks up substances through repeated impact. The mill is a type of vertical shaft impactor mill and consists of two rotating discs with pins embedded on one face. The discs are arrayed parallel to each other so that the pins of one disk face those of the other. The substance to be

homogenized Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity of a substance or organism. A material or image that is homogeneous is uniform in composition or character (i.e. color, shape, siz ...

is fed into the space between the disks and either one or both disks are rotated at high speeds. Pin mills can be used on both dry substances and liquid suspensions. Pin mills are commonly use in the manufacture of

pharmaceuticals A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and rel ...

, as they can achieve particle sizes as low as a few micrometers. However, heat generated by

friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of t ...

can sometimes be a concern. A manual form of the mill is commonly used to grind

marijuana Cannabis, also known as marijuana among other names, is a psychoactive drug from the cannabis plant. Native to Central or South Asia, the cannabis plant has been used as a drug for both recreational and entheogenic purposes and in various tra ...

to a useful consistency.

References

{{Reflist Grinding mills