Demystifying Mesh Sizes in Mesh Filters: What You Need to Know

Mesh filters are used across various industries for filtration, separation, and particle sizing. One of the critical factors in choosing the right mesh filter is understanding mesh size. Here's a breakdown of the key concepts.

1. What is Mesh Size?

Mesh size refers to the number of openings per inch in a mesh screen. It is a measurement of the density of the mesh, indicating how tightly the wires are woven. For example:

• 10 mesh means there are 10 openings per inch.
• 100 mesh means there are 100 openings per inch.

The larger the mesh number, the finer the filter will be, as there are more openings to pass smaller particles through the screen.

2. How Mesh Size Relates to Particle Size

The size of the openings between the wires determines the size of the particles that can pass through the mesh. For instance:

• A 100 mesh filter will allow particles smaller than 149 microns to pass through (since 100 mesh roughly corresponds to 149 microns).
• A 20 mesh filter will allow particles smaller than 841 microns to pass.

Mesh sizes and their corresponding particle sizes can vary slightly depending on the material of the mesh and how it is woven.

3. Types of Weave in Mesh Filters

Mesh filters come in different weave types, which affect the strength and filtering precision:

• Plain Weave: Most common, where each wire alternates over and under, providing uniform openings.
• Twill Weave: Wires pass over two or more wires, offering better strength and finer filtration.
• Dutch Weave: More wires are packed together in one direction, creating finer filtering capability for very small particles.

4. Choosing the Right Mesh Size

When selecting the appropriate mesh size for your application, consider:

• Desired particle size: For finer filtration, select a higher mesh size.
• Flow rate: Finer mesh sizes can reduce flow rates due to smaller openings.
• Material compatibility: Ensure that the mesh material (stainless steel, nylon, etc.) can withstand the conditions of your process.

5. Mesh Size and Microns

Mesh size and microns are often used together to specify filtration levels. Here’s a rough guide to some common conversions:

• 10 mesh: ~2000 microns
• 40 mesh: ~400 microns
• 100 mesh: ~149 microns
• 200 mesh: ~74 microns

6. Importance of Wire Diameter

The thickness of the wire used to weave the mesh also impacts filtration. A thicker wire will reduce the open area of the mesh, even if the mesh size remains the same, leading to different filtration properties for meshes with the same mesh number.

Final Thoughts

Understanding mesh size is key to choosing the right filter for your application. Consider the particle size, desired flow rate, material compatibility, and mesh weave to make the most informed decision. A higher mesh size is ideal for fine filtration, while lower mesh sizes work well for filtering larger particles.