How does a triple roll mill work
Posted by Marc Jackman on
A Triple Roll Mill (or Three Roll Mill) is a machine used for fine dispersion and homogenization of pigments within a liquid medium, such as watercolor, oil paint, or ink. It works by passing the material through three horizontally positioned rollers that rotate at different speeds and directions, applying shear force to break down and evenly distribute pigment particles.
How It Works:
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Feeding the Material – The pigment mixture (pigment + gum Arabic/water vehicle) is placed onto the first roller (feed roller).
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Shear Force & Dispersion – As the material moves between the first and second rollers, the increasing speed difference between them applies shear force, breaking down pigment agglomerates and dispersing them into the binder.
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Further Refinement – The now finer material moves between the second and third roller (apron roller), further refining the dispersion.
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Collection – The fully dispersed paint is lifted off the final roller by a scraper blade and either collected for further processing or recirculated for additional passes if necessary.
Why Use a Triple Roll Mill?
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Ensures even pigment dispersion without clumping.
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Produces smoother, more consistent paint.
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Prevents pigments from settling or separating.
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Improves color intensity and stability in watercolor formulations.
For high-quality watercolor production, using ceramic rollers (instead of steel) prevents unwanted chemical reactions with certain pigments, maintaining color integrity.