Why replace metal filter screens with fiberglass filter mesh for molten aluminum filtration?

Metal filter screens, such as: stainless steel wire mesh, have obvious limitations when filtering high-temperature molten aluminum.

Fiberglass filter screens are specially developed for aluminum casting and become the preferred choice for aluminum liquid purification.

1. High temperature chemical inertness

Molten aluminum is highly corrosive at 700℃~760℃.

❌Stainless steel or other metal mesh will react with molten aluminum at high temperature. Aluminum will erode and alloy with the metal mesh, contaminating the aluminum liquid, forming intermetallic inclusions, and causing defects on castings (such as automobile wheel hubs).

✅Fiberglass (E-glass) is completely inert to molten aluminum. It will not dissolve, react or release impurities when contacting high-temperature aluminum liquid, avoiding secondary pollution of molten aluminum.

2. Superior filtration precision & inclusion capture capacity

❌Metal mesh only relies on simple mesh holes to block large inclusions, and can only intercept large particles. Small oxide slag and fine alumina inclusions can easily pass through the metal mesh.

✅Fiberglass filter screen adopts three-dimensional fiber stacked structure. It can not only block large slag, but also adsorb tiny oxide inclusions on the fiber surface, greatly improve the purity of aluminum liquid, reduce pores and slag inclusion defects of castings, and improve the yield of aluminum castings.

3. Thermal shock resistance & matching casting process

❌Metal mesh will have thermal stress deformation when encountering high-temperature molten aluminum, the mesh will be deformed and the pore size will change, even broken, leading to slag leakage.

✅Fiberglass filter has good thermal shock resistance. It will not deform or break instantly when molten aluminum flows through. It can maintain stable structure during the whole pouring process.

4. Lower cost and easier installation

❌Metal filter mesh is expensive and heavy. It needs special fixing structure in the gating system.

✅Fiberglass filter screen is lightweight, easy to cut into required size, easy to place in the sprue cup, runner, low cost, suitable for mass casting production.

5. No residual metal impurity risk

❌If metal mesh breaks, metal fragments will fall into molten aluminum, forming hard spots inside aluminum castings, seriously affecting the mechanical performance of finished products.

✅Broken fiberglass fibers are non-metallic inclusions, which have less destructive impact on aluminum workpieces compared with metal debris.

FAQ

1. Why is fiberglass filter mesh better than metal mesh for molten aluminum filtration?

Metal wire mesh will react and alloy with high-temperature molten aluminum, introducing metallic impurities and causing hard spot defects in aluminum castings. Fiberglass mesh features excellent chemical inertness against molten aluminum. It will not dissolve or react when exposed to 700~760℃ molten aluminum. Its 3D fiber structure captures fine oxide inclusions that easily pass through plain metal mesh. It also has good thermal shock resistance, low cost and simple installation for foundry mass production.

2. Will fiberglass filter mesh break and bring impurities into molten aluminum?

Our fiberglass mesh is made of high-purity E-glass yarn, specially treated for aluminum casting. Under normal pouring operations, it maintains stable structure without breaking. Even in extreme cases of damage, the fiber fragments are non-metallic inclusions, which cause far less damage to aluminum castings than metal debris falling from broken metal mesh.

3. What temperature range can the fiberglass filter mesh withstand for molten aluminum?

It is designed for molten aluminum casting, stably working at 700℃ ~760℃, perfectly matching the conventional pouring temperature of aluminum alloy.

4. Can metal filter mesh fully filter tiny alumina slag?

No. Metal mesh is a 2D screen structure, which only blocks large slag particles. Fine alumina oxide films and micro inclusions can easily pass through the mesh holes, resulting in hidden slag inclusion defects inside castings like automobile wheel hubs.

5. Is it easy to install fiberglass filter mesh in the gating system?

Yes. It is lightweight and flexible, can be cut into custom sizes. It can be directly placed in sprue cups or runners, no complicated fixing structure required, much easier to install than heavy metal mesh.