Processing of Printing Inks with Colloid Mills

From high-flow gravure varnishes to paste-like offset inks, printing inks span a wide spectrum. Pigments and additives must be dispersed so finely that hue, density and gloss remain consistent; at the same time, viscosity has to remain stable in the mill and on press, while entrapped air or voids can quickly spoil the print. This is exactly where PUC colloid mills excel.

Precise particle-size control in a single cycle

The continuously adjustable rotor–stator annular-gap system combines cutting, impact, friction and shear forces, breaking down agglomerates to the sub-micron range in one event. Cycle times fall and over-milling is avoided.

Wide viscosity window – from flexographic ink to offset paste

PUC mills handle formulations from <100 cP up to 80,000 cP. Machine size, gap setting, and an optional recirculation module adapt the unit to a tailor-made dispersion tool for solvent-, oil-, or UV-curable systems.

Process reliability and hygiene

• Choice of single- or double-acting mechanical seals and PTFE lip seals cover water-, oil-, and solvent-based inks
• ATEX-compliant, sterilisable, and heat-/cool-jacketed versions keep solvents under control and prevent temperature spikes
• Closed inline configuration minimises oxygen and dust ingress

Complete drainability and easy cleaning

Vertical housings empty automatically; horizontal designs feature low-point outlets, so material losses stay in the gram range. Polished, CIP/SIP-capable surfaces and quick-release fittings cut colour or product change times.

Scalable from laboratory to full-on production

The PUC 60 laboratory mill works with the same shear geometry as our production units, allowing specifications to be scaled up one-to-one.

Decades of cross-industry experience

Since 1926, Probst & Class has supplied colloid mills to virtually every branch of the processing industry—from chemicals, paints, and coatings to food, cosmetics, pharmaceuticals and petrochemicals. This wealth of know-how informs every design detail and makes PUC mills dependable components in new and existing production lines.

Investment security and low total cost of ownership

PUC has supplied spare and wear parts for decades, irrespective of a machine’s year of manufacture. Reliable parts availability, robust stainless-steel construction, and energy-efficient drives keep TCO low and shrink the  ecological footprint of your business.

Advantages of printing ink processing

• Maximum colour strength and gloss thanks to the tight particle-size distribution
• Fewer nozzle or screen defects owing to the absence of coarse particles
• Reproducible rheology – stable viscosity on the mill and the press
• Minimal material loss due to complete drainability
• Short cleaning and changeover times during colour shifts
• Long-term parts availability safeguards investment and lowers TCO
• Sustainable inline workflow: lower VOC emissions, no open vessels
• Seamless scale-up to 80 m³/h

With a PUC colloid mill you invest in more than a machine—you acquire a process-secure, future-proof plant component for the economical production of high-quality printing inks from gravure to UV digital.