How to make a wedge wire screen?

Making a wedge wire screen involves a precise manufacturing process that combines wire forming, welding, and shaping to create the characteristic slotted openings. The goal is to produce a durable and efficient filtration element with uniform slot sizes that can effectively separate particles based on their size.

Here's an overview of the steps involved in making a wedge wire screen:

1. Material Selection

Wire Material: Choose a material suitable for the application. Common materials for wedge wire screens include stainless steel (e.g., 304, 316), which is resistant to corrosion, high temperatures, and harsh chemicals. For specific applications, materials like carbon steel, titanium, or other alloys may be used.

Support Rod Material: The central support rods that will hold the wedge wires in place are also usually made from stainless steel or other high-strength alloys.

2. Wire Forming (Wedge-Shaped Wire)

Welding the Wire: The process begins by forming the wire into a wedge shape. A wire is passed through a special machine that draws it into the desired shape—typically a flat, wedge-like profile. The width of the wire and the angle of the wedge are critical in determining the size and shape of the filtration slots.

Customization: The wedge wire’s size, thickness, and slot openings are designed based on the customer’s filtration needs (such as the particle size to be filtered). This process allows for precise control over the slot sizes.

3. Slot Opening Size

The width of the slots is determined by the space between the wedge wires. The slot size can be customized to filter different particle sizes based on the application (e.g., large slots for coarse filtration or fine slots for precision filtering).

Slot Arrangement: The slot configuration typically includes a consistent gap between the wedge wires. The wedge wire is designed such that the narrow edge is facing inward, while the wider edge faces outward, allowing for greater flow capacity and easier cleaning.

4. Forming the Screen Shape

Tubular Shape (for tube screens): For applications requiring a cylindrical wedge wire screen, the wedge wire is wound around a central support rod or mandrel. The wedge wire is then welded or mechanically bonded at regular intervals to ensure that the wire forms a secure, cylindrical shape.

Flat Panels (for flat screens): For flat wedge wire screens, the wire is laid out in a grid or mesh pattern, with the wires placed perpendicular to each other. The wedge-shaped wires are welded onto horizontal support rods, creating a flat sheet with the desired slot openings.

5. Welding the Wires to Support Rods

Spot Welding: The wedge wires are spot-welded onto a series of support rods, which are positioned in parallel to one another. This step ensures that the wedge wires are securely held in place.

Welding Techniques: In many cases, fusion welding or resistance welding is used to join the wedge wire to the support rods. The welding process must ensure a strong, permanent bond that will hold under pressure and resist wear.

6. Trimming and Shaping

After the wires are welded into place, the screen may be trimmed to the desired size and shape. This may involve cutting the cylindrical screens to the correct length or trimming the edges of the flat screens.

End Caps and Mounting: For cylindrical screens, the ends of the tube may be fitted with end caps to prevent damage and help secure the screen in place within filtration systems.

7. Surface Treatment and Finishing

Cleaning: The wedge wire screen is cleaned to remove any oils, debris, or contaminants from the manufacturing process. This is typically done through chemical or mechanical cleaning methods.

Passivation: For stainless steel wedge wire screens, a passivation process may be applied to improve corrosion resistance. This typically involves immersing the screen in a chemical solution that removes free iron particles from the surface and forms a protective oxide layer.

Coatings: In some cases, additional coatings or treatments (e.g., galvanizing or powder coating) are applied to increase corrosion resistance, especially for screens used in harsh or outdoor environments.

8. Quality Control and Testing

Slot Size Check: The slot size is checked for uniformity and accuracy using precise measuring tools. This ensures that the wedge wire screen will filter the correct particle size as designed.

Strength Testing: The screen is tested for structural integrity and strength. This could include pressure testing to simulate real-world conditions and ensure that the screen can handle the mechanical stresses of filtration.

Flow Rate Testing: In some cases, the flow capacity of the wedge wire screen is tested to confirm that it can handle the required volume of liquid or gas without clogging or causing excessive pressure drop.

9. Packaging and Delivery

Once the wedge wire screen passes quality control, it is carefully packaged and prepared for delivery. For tubular screens, the products may be wrapped and bundled for transport, while flat panels may be securely stacked or rolled, depending on their size.