Private Label & OEM2 min read

Bulk Coating Rheology: Yield Stress Is Not Another Name for Viscosity

A viscosity value and a yield-stress result address different aspects of flow behaviour. Ask which property is relevant to the intended filling or application process before comparing candidate bulk formulations.

Updated · NANOLAB Knowledge

The key distinction

Yield behaviour concerns the transition towards flow under an applied stress, whereas viscosity describes resistance to flow under stated conditions. The reported result depends on the measurement approach and the material's behaviour.

Practical checks

  1. Define the operational question before ordering a test.
  2. Keep the method and conditions with the result.
  3. Ask the technical team how the measured property relates to the approved process.

Example

Illustrative example: a buyer wants to understand whether a formulation moves during a specified dispensing operation. A single viscosity number, without a suitable test context, may not answer the starting-flow question.

Scope and limits

This article provides terminology, not a filling setting or formulation recipe. Do not infer a universal yield threshold, shelf life or application instruction from the property name.

Related guidance

Technical references: Anton Paar: rheology terminology. These sources describe their stated methods or products; they do not certify NANOLAB products or establish compatibility with an unlisted surface.

Discuss bulk supply and private-label requirements with NANOLAB. Use the current product documentation for formulation-specific instructions.