Rheology & Viscosity From A to Z: Flow Behavior, Practical Testing & Smart Use of Modifiers

Get tangible data and directions from rheology by knowing how to translate pourability, sag resistance… into rheology targets (complex modulus, yield stress, shear rate...).

Joshua Marsh will provide a clarity around the core fundamentals without the complexity of equations, that enables efficient management of the rheological profile of your product.

Support your developments by selecting the right rheology test in practice.

Course Outline

• Module 01:

  Introduction

  • What is rheology?
  • What are structured fluids and viscoelastic materials?
• Module 02:

  The Rheologist’s Toolkit of Parameters: Identifying the information critical to your products and processes

  • Structure Parameters:
    - Phase Angle
    - Complex Modulus
    - Elastic and Viscous Moduli
    - Compliance
    - Zero-shear Viscosity
  • Yield / Recovery Parameters:
    - Yield Stress
    - Yield Strain
    - Thixotropic Breakdown Rate
    - Thixotropic Recovery Rate
    
  • Flow Parameters:
    - Viscosity at Relevant Shear Rate
    - Infinite Shear Viscosity
    - Viscosity-profile Parameters

• Module 03:

  Understanding viscoelasticity and the concept of elasticity in liquids

  • Definition of "solidity" / elasticity
  • How to measure "solidity": the oscillation technique
  • Viscoelastic parameters explained
    - Comparing food products: Hotdog mustard vs cream cheese
    - Comparing topical products of varying “stiffness”: Ointment, lotion & cream
    - Viscoelasticity and timescale

• Module 04:

  Back to the Rheologist’s Toolkit: What have we learned?

Generate relevant and useful rheological data to support your developments by selecting the right rheology test (controlled rate or shear, rotational or oscillatory...) & interpreting test results correctly.

Joshua Marsh will guide you through the vast range of methods and equipments available, share pros & cons and practical considerations to help you determine the one most suited for you.

Course Outline

• Module 01:

  The Rheologist’s Toolkit: Introduction & Metrics

• Module 02:

  Selection and Development of Tests

• Module 03:

  Rheometers and Viscometers: The key differences: cost, capability, performance, and ease of use

  1. Controlled stress and “high performance” rheometers
  2. Brookfield-type spindle viscometers
  3. Accessories: Cones, plates, cylinders, etc.
• Module 04:

  Critical Parameters for Characterizing Your Products

• Module 05:

  Rheology and viscosity test methods (suspensions, emulsions, solutions, and gels) :

  1. Pros and cons of procedures for testing
  2. Viscosity profiling methods
  3. Obtaining repeatable and relevant viscosity values
  4. Quantifying yield stress and thixotropy
  5. Oscillatory test methods for viscoelastic profiling
• Module 06:

  Tips for Buying a Rheometer or Viscometer

Take control on stability, sag resistance, leveling… by optimizing rheology modifiers selection & loading, especially with latest associative technologies (polyurethane, hectorite organo clays…)

Johan Bieleman will explain how to best suit your new system constraints (low VOC, high shear…) while avoiding unwanted interactions with other paints ingredients (colorants, surfactants…)

Course Outline

• Module 01:

  Introduction: Rheology and the role of thickeners.

• Module 02:

  Characteristics of main paint thickeners:

  • Associative thickeners (polyurethane, hectorite organoclays, etc.), hydrogenated castor oils, PA, cellulosics, acrylates, clays...
  • Advantages and limitations
  • Compatibility with other ingredients
  • Main application areas
• Module 03:

  How to select the right rheology modifiers for solventborne and waterborne systems depending on your needs:

  • Coatings performance (sag resistance, flow & leveling, etc.)
  • Film properties (gloss, water resistance, etc.)
  • Application requirements
• Module 04:

  Practical examples:

  • Roof coating
  • Matt emulsion paint
  • SF epoxy airless spray, etc.
• Module 05:

  Summary