Sand moulds and cores mfr using the cold-box process - with initial injection of air into shooter chamber before main shot

摘要

Sand mixed with a synthetic org. binder is shot into a mould- or core-box and the mixt. is then hardened instantaneously at room temp. using a catalyst gas. Air at a pressure of 0.01-2 bars is injected into the sand mixt. in the shooter to put the mixt. into suspension; 0.01-0.1 seconds later, a second, -arger air pressure is used to shoot the mixt. into the moulding box. The pref. machine has a coaxial, perforated pipe mounted inside the shooter chamber for carrying out first stage; filters are used on the air supply so that sand does get into the air lines and facilities are provided for clamping the mould- or core-box, making the shot, gassing the mould and ejecting it.