Pigments are used for the coloring of paint, ink, plastic, fabric, cosmetics, food and other materials. Most pigments are dry colorants, usually ground into a fine powder. As such they are suspended in a medium or vehicle for use in production. Toner is also a powder but used specifically in laser printers and photocopiers to form the printed text and images on the paper. Toner particles are melted by the heat of the fuser, and bind to the paper.
Particle size data is vital for the efficient formulation and manufacture of pigments for various applications, because of the direct correlations between particle size and pigment performance. Laser Diffraction and Dynamic light Scattering (DLS) are the most commonly used techniques and meet the need for robust and reliable particle size measurement in the nanometer and micrometer range. The wide, dynamic range of laser diffraction makes it possible to track dispersion and milling processes from start to finish, while at the same time enabling highly effective agglomerate detection. The introduction of dynamic imaging accessories that add visualization capabilities to laser diffraction systems are especially helpful in this regard and aid both agglomerate detection and identification. The ability of DLS to measure particle size at relatively high concentration makes it a useful complement to laser diffraction, in the size range of most interest to ink manufacturers.
Complimentary technologies from Malvern Panalytical include Rheometry, Morphological Imaging and Electrophoretic Light Scattering (ELS). Rheometers measure the rheological characteristic of pigment dispersions, which influence processes such as jetting, sedimentation and leveling behavior. ELS is used to measure Zeta potential of a dispersed pigments, which is related to dispersion stability, and Morphological imaging is used to determine and classify the particle size and particle shape of pigmnet and toner particles. Together, these technologies can help pigment manufacturers optimize production processes and produce market leading products at a competitive price.
In summary, Malvern Panalytical's range of characterization techniques and application knowledge can be used to:
- Characterize the particle size and polydispersity of pigment and toner particles
- Assess and control pigment aggregation or dispersion stability
- Image and classify particles in terms of their size and shape.
- Determine and control the flow characteristics of pigment dispersions