Coating color preparation and characterization
The coating laboratory is well equipped for preparation and characterization of coating colors. The properties that can be characterized include:
- Pigment brightness;
- Pigment oarticle size distribution from sedimentation (Sedigraph) and light scattering (Malvern);
- Low shear rate rheology;
- High shear viscosity;
- Water retention of coating colors.
Coating equipment
The laboratory coater, Heliocoater is used to apply pigment coatings to different substrates. Another faster technique is down-draw rod coaters.
Coating layer and coated paper characterization
Innventia has an advanced instrument park to characterize surfaces, both physically and chemically. Some of the analyses are:
- Coating coverage and coat weight distribution: SEM, burn-out.
- Surface topography with optical non-contact techniques: FRT and OptiTopo.
- Coating pore structure.
- Contact angle, surface energy amd acid-base properties.
- Drop absorption of drops sized from 35 pl to 4 ml.
- Characterization of uniformity in absorptivity.
- Contact area under compression.
- Uniformity in surface compressibility.
- Mechanical properties of coating layers: pick tests, stress-strain curves for coating layers.
- Water induced waviness of coated paper (simulation of fluting in heat-set web-offset printing).
Distribution map, showing the non-uniformity in pressure uptake for a coated paper that is subjected to a pressure of 20 MPa.
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