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Air set moulding from Arrow Butler
Castings
Air set moulding was developed as a production process
to help compensate for the ever-increasing demands of the casting buyer.
Air set sand moulding produces a sand mould of considerable strength,
which can be free standing without the need for moulding boxes and
therefore unlimited in size.
The process
requires graded kiln dried sand, which is mechanically mixed with a resin
to bind the sand together. A chemical hardener is then added to the sand
mix, which reacts with the binder and begins to set the sand into a solid
form. At this point the fluid sand is rammed around a pattern or multiple
patterns. Once rammed the sand is left to set. Setting time being
dependent on the type of hardener used, be it a 3-minute hardener or a
30-minute hardener. The sand literally sets into a solid block from which
the pattern equipment is drawn. Cores are then added to the mould and the
mould closed ready for casting.
Air set moulds allow for much larger, intricate
castings to be produced. A solid sand structure allows the mould to be
literally built from its individual pieces. Castings of complexity can be
produced which may otherwise have to be fabricated from individual parts.
An air set mould is best suited to larger heavier castings as the mould
strength allows for greater weight of metal to be cast, sand use can be
kept to a minimum without compromising quality so production costs are
reduced.
Arrow Butler Castings uses state of the art foundry equipment on
its air set line, which allows 100% reclamation of the primary raw
material, sand. This reclaimed sand is broken down, cooled and filtered,
to be used again and again. To maintain sand quality and mould strength
the reclaimed sand is mixed with new sand at a ratio of 75%: 25%
respectively. This process keeps production costs to a minimum without
compromising quality.
Aware of environmental issues, we have found
a useful outlet for our waste sand. The sand is taken free of charge from
site and used in other production processes eliminating dumping costs and
therefore making savings which can be passed on to the casting
buyer.
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