Specifications and Performance Parameters of Extruder Filter Mesh

Specifications and Performance Parameters of Extruder Filter Mesh
The main specification parameters of extruder filter mesh determine its filtration accuracy and compatibility with the equipment. They mainly include the following aspects:

Core Performance Parameters

• Mesh Count: A core indicator measuring filtration accuracy, referring to the number of openings per inch of length. Typically between 20 and 200 mesh, some can reach 800 mesh. Higher mesh means smaller openings and finer filtration.

• Filtration Accuracy: Directly reflects the size of particles the filter mesh can intercept, typically ranging from 1 to 800 microns.

• Open Area: The ratio of the total opening area to the total area, directly affecting back pressure and output when melt passes through. Higher open area means lower back pressure and higher output, but filtration capacity decreases accordingly.

• Material: Determines the temperature resistance, corrosion resistance, and applicable materials.

  • Black wire cloth: Low cost, suitable for general coarse filtration.

  • *Stainless steel 201, 304/316L*: Mainstream materials with strong corrosion resistance. 316L is especially suitable for food, medical, and high-temperature applications.

  • Special alloys: Used for highly corrosive materials such as fluoropolymers and PVDC.

Geometric Dimension Parameters

• Wire Diameter: The thickness of the metal wire forming the filter mesh, ranging from 0.016mm to 3mm. For the same mesh count, thinner wire diameter achieves higher open area but lower strength.

• Dimensions:

  • Shapes: Common shapes include round, square, oval, annular, etc.

  • Size: Disc diameters range widely, from 5mm to 1000mm. Conventional sizes are mostly between 50mm and 300mm.

  • Tolerance: Indicates the precision of the filter mesh outer diameter processing, directly related to effective sealing after installation to prevent material leakage.

• Product Form: Determines the application scenario.

  • Mesh disc type: The most common disc-shaped filter mesh, used for manual or hydraulic screen changers.

  • Mesh belt type: Long strip-shaped filter mesh, typically up to 10 meters in length and 40mm to 210mm in width, used for automatic screen changers, enabling non-stop screen changes.

• Combination Type: Divided into single-layer and multi-layer (up to 5 layers). Multi-layer structures use a “coarse-fine-coarse” arrangement to balance filtration accuracy and mechanical strength.

Process Structure Parameters

• Weave Type: Affects filtration accuracy, strength, and melt flow characteristics.

  • Plain Weave: Stable structure, most widely used.

  • Twill Weave: Better flexibility and permeability.

  • Dutch Weave: Extremely high filtration accuracy, often used for ultra-fine filtration.

  • Reverse Dutch Weave: Often used for belt-type screen changers, high strength, excellent filtration performance.

• Layer and Arrangement: Multi-layer filter meshes are typically arranged in a “coarse-fine-coarse” structure. For example, a typical arrangement might be: the top and bottom layers are 20 mesh coarse mesh for support, with an 80 mesh fine mesh in the middle for main filtration.

Engineering Performance Parameters
These parameters concern the service life and stability of the filter mesh under extreme conditions.

• Working Temperature: The temperature range in which the filter mesh can work stably for a long time. Typical values are between 120°C and 500°C, depending on the material.

• Working Pressure: The melt pressure the filter mesh can withstand, typically between 0.5 MPa and 4.0 MPa.

• Burst Strength: Measures the ability of the filter mesh not to be burst under high pressure. This is an important mechanical performance indicator, with standard samples typically required to test no less than 15 MPa.

• Wear Resistance: Especially important when processing materials containing fillers (e.g., calcium carbonate, fiberglass) or recycled materials. High wear resistance means longer service life.

Selection Key Points and Combination Use
In actual production, filter mesh selection is not a single dimension but a comprehensive consideration of multiple factors. It is usually necessary to combine raw material characteristics, product quality requirements, equipment configuration, and cost control to determine the most suitable filter mesh type.

Typical Specification Parameters Quick Reference Table
For easy reference, the table below summarizes the approximate correspondence of common filter mesh specifications, which can be used for preliminary matching and selection in actual production.