Results of a series of tests: For the casting of aluminium rims, sprue filters made of wire mesh ensure optimum process reliability.

In the production of aluminium rims, the correct selection of sprue filters is essential for low reject rates.

Filters made of glass fabric with disadvantages:
In the series of tests and subsequent X-ray examinations, it was found that filters made of glass fabric did not prove themselves in series production, as the material becomes unstable under the influence of temperature, so that in some cases the filters soften and are washed away with the material flow, although the filters were provided with deformations in order to increase stability. (Mexican hat shape)
Unfortunately, glass fabric offers only limited possibilities,
to vary mesh widths and material thicknesses as with strong fabrics a deformation inevitably leads to material breakage.

Filters made of wire mesh and expanded metal are advantageous when properly pre-treated:
The results of the tests with wire mesh filters clearly documented that these filters are stable in position so that there is no risk of the filters being flushed away.
In the case of wire mesh and expanded metal filters, however, the pre-cleaning of the filters is of great importance, as the filters have adherences of greases/oils due to production, which must be removed after manufacture and forming.
Filters made of wire mesh can be optimally adjusted to the requirement profile, since mesh size and wire thickness can be selected to meet specific requirements.

Evaluation:
After evaluating the test series, we must advise against the use of glass filters in the manufacture of aluminium rims, as no process reliability is guaranteed. The use of sprue filters made of wire mesh is preferable, especially since the filter parameters can be optimally adapted to the requirements and appropriate pre-treatment is ensured.