Cathode Bags for Anodizing Lines

A different electrode, a different job

This product is the outlier in the category, and that is worth knowing before you compare it with the anode bags.

An anode bag encloses the anode and holds particulate residue where it is produced. A cathode bag works at the opposite electrode and in a different process. It is pulled over cathode profiles in an anodizing line, where it forms a textile cover.

The two products share a material and a manufacturer. They do not share a function, and a common micron comparison table between them would be misleading. There is no micron rating on this page for that reason.

What the cover can do

Hydrogen is evolved at the cathode of an anodizing line during operation. Rising bubbles can carry fine droplets of electrolyte with them to the bath surface, where they disperse as an aerosol.

A textile cover over the cathode profile can contribute to reducing the carry-over of those droplets. That is what this product is intended for.

This needs to be stated precisely, because the subject touches occupational safety. We do not warrant that aerosols are prevented. We give no figure for an achievable reduction in per cent, because that would require measurements on your specific line. And we make no statement about compliance with occupational safety law; that assessment is made by the operator together with the responsible safety specialist.

Nor does a textile cover replace extraction or any other engineering control. It can be one element, not the solution.

Fit is the decisive question with this product

Cathode profiles in anodizing lines differ considerably: in cross section, length, suspension, contacting and installation situation. There is no blanket suitability for all profiles.

To assign the right size we need concrete information: profile cross section and dimensions, the length of the zone to be covered, how the profile is suspended and contacted, the bath composition and temperature, and a photograph of the installation. With those we can tell you whether a standard size fits or whether a made-to-measure cover is the better route.

For profiles outside the standard range we make textile covers to your dimensions. Where a contour is complex, the blank is cut on our laser system, which reproduces the same shape from part to part.

Cathode bags for anodising, cathode socks or cathode filter bags

Several names are in circulation for the same part, which regularly sends buyers the long way round. Cathode bags for anodising, spelled the British way, are the same product as cathode bags for anodizing in American spelling, because both words describe the same process. Some plants say cathode sock, others cathode filter bag or simply cathode cover.

In German the same product is a Kathodenbeutel or Kathodensack, and the process is called Eloxal. If you are working from a German drawing or a German parts list, those are the terms you are looking for.

Material, sizes and limits

The material is polypropylene with a maximum working temperature of 90 °C.

Polypropylene is resistant to many aqueous media. Whether it suits your anodizing bath depends on composition, concentration, temperature and operating conditions. We do not warrant blanket acid resistance; that check belongs before the order, not after it.

Fabric construction and fabric weight are deliberately left open. We publish confirmed figures only, and for this product they are not yet confirmed in the item master. If you need them for a specification, ask us and we will obtain them for your enquiry.

Frequently asked questions about cathode bags for anodizing

The questions come from anodizing plants and concern fit, effect and material suitability.

What does a cathode bag do?

It is pulled over suitable cathode profiles in an anodizing line as a textile cover. It can contribute to reducing the carry-over of liquid droplets at the bath surface.

Does it prevent acid mist?

No, and we do not warrant that. It can contribute to a reduction. A figure in per cent would require measurements on your specific line, and an assessment under occupational safety law is made by the operator together with the responsible safety specialist. The cover does not replace extraction or any other engineering control.

Will the bag fit my cathode profile?

Geometry decides. Send us the profile cross section, the dimensions, the length of the zone to be covered, the suspension and a photograph of the installation. With that we can assign a standard size or quote a made-to-measure cover.

Is a cathode bag the same as an anode bag?

No. An anode bag encloses the anode and holds particulate residue back there. The cathode bag works at the opposite electrode and has a different job. Confusing the two leads to wrong orders.

Is the material acid resistant?

Polypropylene is resistant to many aqueous media and the maximum working temperature is 90 °C. We do not warrant blanket acid resistance; suitability for your bath is assessed from composition, concentration and temperature.

Do you make special sizes?

Yes. For profile geometries outside the standard range we manufacture to your dimensions, with laser cutting where the contour needs to be reproducible.

Is anodising the same as anodizing?

Yes. The two spellings describe the same process, British and American. Our cathode bags for anodising and our cathode bags for anodizing are the same product.