Filtration effectiveness is largely dependent on the correct application and positioning of the filter. Foseco Application Engineers are able to provide technical application support for the calculation and design of gating systems.
Filters are manufactured in a variety of sizes and porosities are available as follows:
SEDEX SiC Ceramic Foam Filters
SEDEX is a range of silicon carbide based ceramic foam filters designed for use in grey and ductile iron applications to provide a smooth laminar flow of molten metal and prevent the ingress of slag, magnesium reaction products, inoculant residues or sand grains into the mould cavity. The maximum application temperature for SEDEX filters is 1500 °C.
The high filtration effectiveness combined with a reduction in turbulence often allows gating systems to be greatly simplified. SEDEX filters can be positioned vertically, horizontally, or diagonally in a suitably designed runner system.
SUPER SEDEX Ceramic Foam Filters
SUPER SEDEX is a range of new generation silicon carbide based ceramic foam filters with a consistent, high level performance in terms of metal flow rate and filtration efficiency. The consistent pouring times and enhanced flow rate characteristics make SUPER SEDEX ideally suited for vertically parted moulding applications such as DISAMATIC.
The improved open pore ceramic structure of SUPER SEDEX allows foundries to:
- Use finer porosity for higher filtration efficiency
- Maintain uniform pouring times
- Achieve improved metal flow rates
SEDEX ULTRA Ceramic Foam Filters
SEDEX ULTRA ceramic foam filters represent the latest development in the filtration of ductile, grey and malleable iron castings. Using a unique production process, the edges of the filter are closed on all 4 sides, resulting in improved edge definition.
The closed edges of the SEDEX ULTRA filter also give improved handling characteristics, particularly with automated placement systems. Furthermore the consistently more open pore structure of these filters provide advanced flow characteristics enabling foundries to employ finer and/or smaller filters, whilst maintaining their pouring times and metal flow rates. These characteristics make SEDEX ULTRA ideally suited for vertically parted moulding applications such as DISAMATIC.
STELEX PrO High Capacity Ceramic Foam Filters
STELEX PrO is a range of carbon aluminium oxide ceramic foam filters and are particularly suited to the production of white iron and large ductile iron castings. Previously, it has not been possible to filter these castings due to problems with chill, filter capacity and filter strength. Practical experience has shown the benefits of filter-clean castings and, more specifically, improvements in surface finish leading to significant savings in fettling and cleaning operations.
Round filters are more commonly used in KALPUR direct pour applications where they are located inside an insulating or exothermic feeder sleeve, with optimum feed characteristics being achieved when the filter is allowed to float after pouring.