Bingham Plastic

Definition

A Bingham plastic is a type of non-Newtonian fluid that behaves like a solid until a certain yield stress is applied, at which point it flows like a viscous liquid. This property makes Bingham plastics significant in various applications, as they can resist flow under low stress but become workable when enough force is applied. Examples include materials like toothpaste and some types of mud or slurries, where the yield stress must be overcome for them to deform and flow.

5 Must Know Facts For Your Next Test

1. Bingham plastics require a specific yield stress to start flowing, making them behave differently than Newtonian fluids, which flow continuously regardless of stress.
2. They are commonly found in everyday products such as mayonnaise, toothpaste, and some types of paint, allowing for ease of application once enough force is applied.
3. The flow behavior of Bingham plastics can be mathematically described using the Bingham model, which incorporates both the yield stress and the dynamic viscosity.
4. In industrial processes, understanding the properties of Bingham plastics is crucial for predicting how materials will behave during mixing, pumping, or extrusion.
5. Bingham plastics exhibit a unique combination of solid-like and liquid-like behavior, making them essential in applications where controlled flow is necessary.

Review Questions

• How does the concept of yield stress differentiate Bingham plastics from other types of fluids?
  • Yield stress is a key characteristic that differentiates Bingham plastics from other fluid types. Unlike Newtonian fluids that flow easily under any amount of applied stress, Bingham plastics remain solid-like until a specific yield stress threshold is reached. This means that they can withstand some forces without flowing, which is particularly useful in applications where stability is needed until sufficient force is applied.
• Discuss the practical implications of Bingham plastic behavior in manufacturing processes.
  • The behavior of Bingham plastics has significant practical implications in manufacturing processes where precise control over material flow is essential. For instance, when mixing or extruding materials that exhibit Bingham plastic behavior, understanding the yield stress allows engineers to design equipment that can efficiently apply the necessary force to initiate flow. This ensures consistent product quality and minimizes waste by optimizing material usage during processing.
• Evaluate how the unique characteristics of Bingham plastics impact their applications in everyday products and industrial processes.
  • The unique characteristics of Bingham plastics, particularly their yield stress and dual solid-liquid behavior, greatly impact their applications in both everyday products and industrial processes. For example, in products like toothpaste or paint, their ability to resist flow until enough pressure is applied allows for precise application without spilling. In industrial contexts, this property helps in processes like pumping slurries or emulsions where controlled flow is critical for efficiency and performance. Thus, understanding Bingham plastic behavior enables better design and functionality in a variety of applications.

Related terms

Yield Stress: The minimum stress required to initiate flow in a material, particularly relevant for Bingham plastics.

Viscosity: A measure of a fluid's resistance to flow, which can change based on the applied stress in non-Newtonian fluids.

Non-Newtonian Fluid: A fluid whose viscosity changes with the rate of shear strain, including Bingham plastics which have distinct yield stresses.