Particle Measurement

For the determination of particle size in the nanoscale and submicron range, dynamic light scattering (DLS) is a widely used and established measurement method. Two measuring systems are available for this purpose:

• DLS measuring system as a plug-in probe for particle size analysis of suspended particles in the size range from 1 nm to 10 µm and solid concentrations from 0.01 % to 40 % (the limits are material dependent); can be combined with the IPAS for online particle size determination.
• DLS measuring instrument as cuvette system for size analysis of suspended particles in the range from 1 nm to 10 µm; determination of zeta potential by electrophoretic light scattering
   

By means of static image analysis, particle properties such as size, shape, transparency and number can be determined with spatial resolution. Various measuring instruments are available for this purpose:

• Microscopes with different magnifications of 2.5 x / 5 x / 10 x / 20 x / 50 x for the size range 1 µm - 1000 µm
• Automatic image evaluation system with different magnifications of 2.5 x / 5 x / 10 x / 20 x / 50 x for the size range 1.5 µm - 1000 µm
   

Scanning electron microscopy can be used to characterize, among other things, the size, shape and morphology of particles as well as topographies, surface and material defects down to the nanometer range. In combination with elemental analysis (EDX), a statement can also be made about the composition of the materials. The following equipment is available for this purpose:

• SEM with EDX unit with three different acceleration voltages (5 kV, 10 kV, 15 kV) and a magnification of up to 100,000 x
   

Spatially and time resolved measurement of the transmission of a dispersion is used to analyze the particle or droplet velocity during creaming or sedimentation. This information can be used to determine the particle size distribution (ISO 13318-2). For this purpose, different measuring systems are available for characterization under earth gravity field and accelerated centrifugal field:

• Measuring system for determining the sedimentation velocity in the earth's gravitational field for "fast" segregating systems
• Measuring system for performing accelerated stability analysis for particle systems in the size range from 20 nm to 100 µm
• Measuring system for the determination of dispersibility, stability and the separation phenomenon for completely transparent to completely opaque systems using X-rays
   

The following processes and measuring equipment are available for the application of powder coatings and the evaluation of surfaces:

• Powder coating system
  Hand gun with corona charging
  500 ml fluidizing cup
  Perfect for small quantities
  PowerBoost technology (110kV / 110μA) provides maximum coating performance
  Precise Charge Control - mode (PCC 1μA - 10μA) for high quality coating tasks

• Squeegee system
  Test stand with perforated vacuum plate for sizes up to A3 (297 x 420 mm)
  Hardness test bar with 3 spiral springs for the test ranges: 0-300 g/0-3 N, 0-1000 g/0-10 N,-30 N, with spherical scribe needle ø 1 mm made of hard metal following ISO 1518
  Speed of the transport crosshead: 2 - 500 mm/s with an accuracy of ± 1%.
  heating: max. temperature: 125 °C

• Contact angle measurement
  laboratory tensiometer for the determination of contact angle, surface tensions and energies as well as the wetting behavior of powders 
  portable device for measuring the contact angle of surfaces (with water, diiodomethane)
  Calculation of surface free energy according to the models of Owens-Wendt-Rabel-Kaelble and Wu, Zisman and Fowkes, respectively

• Abrasion resistance: washability and abrasion tester
  for the determination of abrasion resistance
  automatic washability and abrasion tester for test specimens up to 35 mm
  test according to ISO 11998, ASTM D4213, ASTM D2486
  hardness tester with 3 spiral springs for the test ranges: 0-300 g/0-3 N, 0-1000 g/0-10 N, with spherical scribe needle ø 1 mm made of hard metal following ISO 1518

• Thickness measurement of total layers
  Ultrasonic based: Thickness range: 10 µm to 10 cm, accuracy: 2 µm, measuring point by point.
  Thermography-based: Thickness range: 5 µm to 5 mm, accuracy: 2 µm, direct imaging

• Thickness measurement of individual layers of a multilayer structure
  Terahertz: Thickness range: 2 µm to 5 cm, accuracy: 2 µm, point-by-point measurement

• Adhesive strength
  The adhesion tester automatically performs peel tests to evaluate the adhesion/cohesion of coatings to metal, wood, concrete and similar substrates.
  Test stamp size 20 mm
  Standards DIN EN ISO 16276-1, DIN EN ISO 4624, ASTM D4541

The particle size and concentration of pigments, but also that of additives, have a significant influence on the color of a component or dispersion. Different measuring instruments are available at SKZ for color measurement:

• Laboratory instruments with d/8° spherical geometry (reflection / transmission; with/without gloss trap).
• Measuring instruments with 45/0° geometry
• Inline colorimeter (45/0°) with integrated temperature sensor
• Glossmeter (20° / 60° / 85°)