Formed One Piece Etched Stainless Steel Cone Filter Screen 0.3mm Thickness With Flanged Neck

Formed Etched Cone Filter Screen — One Piece, No Seam, No Wire

A flat filter mesh has to be held in a frame and it filters across a single plane. This part does the same job with a different geometry: a cone formed from one etched metal blank, open at a flanged neck and closed at the tip. The screen surface is inclined instead of flat, the part supports itself once it is seated in the neck it protects, and the debris it catches collects away from the inlet rather than lying across it.

Because the apertures are etched into the sheet before forming, every opening on the cone comes from a single phototool. There is no woven wire to unravel, no seam to weld and no braze line to clean around.

Why a cone rather than a flat disc

• More screen area in the same neck: the inclined surface gives a larger open area than a flat disc of matching neck diameter, so the same flow passes at a lower face velocity
• Self supporting: the cone holds its own shape under flow, so it needs no backing grid behind it
• Debris kept off the inlet: particles settle at the tip or on the lower flank instead of blanking off the passage directly behind the neck
• Direction built in: the flange seats against a shoulder, so the screen can only be fitted the intended way
• Insertion: a tapered body guides itself into a bore, which suits small openings on nozzles, injector inlets and breather ports

From flat blank to formed cone

The sequence matters, because forming after etching changes the aperture shape:

• 1. Etch flat: aperture size, pitch and open area are etched into the sheet in the flat condition, where the pattern is dimensionally stable
• 2. Compensate for the form: the flat pattern is laid out so that the finished cone carries the specified aperture count and open area; a formed flank stretches differently from a flat plane, so the flat layout is not simply the cone unrolled at nominal size
• 3. Form: the blank is shaped into the cone or cup by deep drawing, pressing or spinning, depending on cone angle, height and thickness
• 4. Finish the neck: the open end is flanged or rolled so that it has a defined seating face and a clean edge at the inlet
• 5. Finish and inspect: parts are stripped, rinsed, dried, and checked for aperture condition on the formed surface, not only on the flat blank

Openings close to a sharp bend deform more than openings on a gentle flank. Aperture position is therefore reviewed against the bend lines before the tooling is released, and the tip radius is kept large enough that the last row of apertures does not sit on a severe curve.

Aperture pattern on a tapered surface

On a cone the circumference grows from tip to neck, so an equal number of apertures per row automatically gives a higher open area toward the wide end. Two approaches are common: a constant pitch measured in millimetres along the surface, which gives the greatest open area at the neck, or a varying pitch chosen so that the open area stays close to constant over the whole height. Either way the aperture size, the metal bridge between openings, and the sheet thickness are reviewed together, because a narrow opening in a thick sheet etches with a more visible taper through the wall than the same opening in thin sheet.

What is settled at drawing review

Specification

Inspection on each lot

• Neck diameter, flange diameter and seating face condition
• Overall height, cone angle and tip condition against the drawing
• Aperture size and spacing checked on the formed surface, sampled at tip, mid flank and neck
• Open area checked on the finished part, not on the pre-form blank
• Visual check for incomplete openings, etch steps, forming marks and residual resist
• Fit check in a gauge or against a sample mating part where the customer supplies one

Handling, cleaning and packing

Formed screens are stripped, rinsed and dried after etching. A thin cone with a large open area is easily deformed at the tip once it is out of the tooling, so parts are handled in trays rather than loose, and nested cones are separated by an interleaf. Where a customer assembles the part in a clean environment, screens can be supplied electropolished or passivated and packed accordingly. Finished screens are then packed in a rigid carton with the necks protected, since a crushed flange will not seat correctly.

Information needed for a quotation

Send the drawing or sample with the neck and flange dimensions, cone angle and height, aperture size and spacing, target open area, material and thickness, surface finish, first order quantity and destination. Price and timing follow from the drawing: aperture density, cone height, forming steps and surface route each change the etching and forming time involved. Every screen is produced to the customer’s own specification, so this page describes the process rather than a fixed offer.