Understanding and testing the wet and dry properties of coatings

Pigment & Resin Technology

ISSN: 0369-9420

Article publication date: 6 July 2010

73

Citation

(2010), "Understanding and testing the wet and dry properties of coatings", Pigment & Resin Technology, Vol. 39 No. 4. https://doi.org/10.1108/prt.2010.12939dac.002

Publisher

:

Emerald Group Publishing Limited

Copyright © 2010, Emerald Group Publishing Limited


Understanding and testing the wet and dry properties of coatings

Article Type: Training From: Pigment & Resin Technology, Volume 39, Issue 4

Contents

Introduction to test methodology:

  • principles of testing and correlation;

  • quality control and specification;

  • accuracy and precision;

  • repeatability and reproducibility.

Properties of liquid coatings.

Rheology:

  • definitions and units;

  • types of rheological behaviour: shear thinning, thixotropy, extensional flow, etc.;

  • factors influencing viscosity;

  • measurement techniques; and

  • overview of instruments: practical work.

Surface tension and flow

  • wetting and contact angles;

  • surface and interfacial tension;

  • dynamic surface tension;

  • surface tension gradients;

  • control of spreading and flow;

  • film defects: Bénard cells, craters, floating, flooding, orange peel, etc.;

  • measurement of surface tension:characterisation tests; and practical work.

Properties of dry films:

  • mechanical properties: modulus of elasticity; tensile strength; extensibility; impact strength and abrasion resistance; scratch resistance; and

  • adhesion and adhesive performance: destructive and non-destructive test methods;

  • resistance testing: durability and accelerated weathering; corrosion resistance testing;

  • water permeability;

  • appearance tests: gloss and sheen;

  • opacity: contrast rations, scatter coefficients and tint methods.

Standards:

  • purpose of standards;

  • sources of standards: national standards, e.g. BSI; European standards EN; and international standards ISO;

  • standard tests available at PRA.

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