Close-up of the matte surface of an ink print

Matting inks raise the matting-agent dosage to lower gloss; once the powder is not fully wetted, the viscosity soars with it, the transfer on the screen and rubber roller becomes uneven, and the matte level and the abrasion resistance of the print both go off target.

For solvent-free and UV-curing printing ink systems, Chemi Tech supplies the KMT-4009 series dispersant; the dosage is set by the matting-agent grade, the resin system and the target gloss. This grade benchmarks DISPERBYK-2009, with a more controllable supply cycle and response; Chemi Tech runs measured comparisons of the viscosity curve and the print gloss, and matches a fitted grade for the customer.

Advantages of Chemi Tech Dispersants

Chemi Tech KMT-4009 series is a high-molecular polymer type, with a marked viscosity-reducing effect on the matting agent, so the matting-agent dosage can be raised significantly at the same viscosity; moreover, it wets and spreads quickly, and the powder is wrapped by the dispersant in the grinding section, so the matte level and the fineness arrive together; at the same time, it is stable in compatibility with UV-curing systems and does not disturb the curing speed or the adhesion; in addition, its storage stability is good, and the ink does not re-coarsen or cake after standing; compared with imported grades, KMT-4009 is more stable in supply cycle and response time and can serve as a replacement.

Industry Pain Points and Solutions

The viscosity of matting ink running out of control mostly stems from the matting agent not being anchored enough, rather than from the resin's own viscosity being too high; the consequence is uneven transfer and matte-level fluctuation.

The first to show up is the viscosity surge in the grinding section. The matting agent has a large specific surface area, and the unwetted powder sucks away the free component in the resin, so the viscosity rises with it. Chemi Tech fixes the KMT-4009 dosage by the matting-agent grade, and the matting agent is already wrapped by the dispersant before it enters the sand mill.

Next is the uneven matte level on the print surface. The under-dispersed matting agent re-aggregates after drying, the local gloss runs high, and the hand feel turns rough. KMT-4009 wets and spreads quickly, and the matte level and the surface fineness arrive together.

The last point is re-coarsening and caking after storage. The matting agent settles and aggregates while the ink is in storage, and re-grinding is needed after opening the can, dragging out the schedule. Chemi Tech checks against the matting-agent grade and the resin system, re-fixes the KMT-4009 dosage and the grinding time, and the viscosity curve returns to the controllable range.

Typical Operating Conditions and Verification

Customer: an ink manufacturer in Shanghai, for the grinding and blending line of matte UV ink.

The matting-agent dosage was raised. The viscosity exceeded the fitting range of the sand mill. The screen transfer was uneven, and parts of the print surface turned shiny. This ink plant had also used an imported grade, which failed to hold steady. After comparing the matting-agent grade and the resin system, Chemi Tech used KMT-4009 as the dispersant, graded the dosage by the target gloss, and made it an import replacement. As a result, the matting-agent dosage at the same viscosity could be raised, the matte level and surface fineness of the print tended toward uniformity, no re-grinding was needed after opening the can following storage, and the performance matched that of the imported grade.

Frequently Asked Questions

After the matting-agent dosage is raised in a matting ink, why must the dispersant be fixed grade by grade according to the powder?

The surface treatment and particle-size distribution of each matting agent differ, so the anchoring needs differ with them, and the dosage must be fixed grade by grade. Chemi Tech KMT-4009 has completed viscosity-reduction comparisons of multiple matting-agent grades in the lab, and recommends only the dosage range in which both viscosity and matte level stay stable. The matting-agent grade, resin system and target gloss must be fixed together; Chemi Tech gives the scheme through parallel comparison of the viscosity curve and the print gloss.