With the Spartan 4-series of mixer there are many features that are supplied as standard – air injection for all chemical inlets, full set of tungsten carbide tipped mixing blades, variable speed main shaft drive motor, built-in fume extraction ducting, increased thickness of trough doors, programable AC drives on all pumps, leak-free magnetic drive catalyst/hardener pumps and fully comprehensive HMI with material consumption logging – to name but a few!
But the main function of any continuous mixer is to mix sand with a resin and either a catalyst or a hardener (depending on the process used), as well as sometimes 2 or 3 additional liquids or dry powders. This task must be completed within 3 to 5 seconds and must be carried out with almost zero wastage and full control of the additives.
The continuous mixer must produce a consistently homogeneous mix, have the ability to produce small batches or long continuous runs of mixed sand at the touch of a switch, all mixed sand must be of good quality, chemical additions must be at the absolute economical minimum, the mixer must be easy to maintain and of course user friendly.
When a mixer does not perform to the required levels of quality, then typical indicators in the mould are ‘spotting’, ‘striation’ and ‘marble effect’ which will ultimately lead to casting defects if not resolved immediately.
The main variables of a continuous mixer that need to be controlled are Sand Flow, Chemical Addition and Mixing Efficiency. Of course, with the latest Spartan mixers we have all of these bases covered, but if further ‘fine tuning’ or improvements to an old mixer are required then Omega Sinto Foundry Machinery Ltd offers the ‘add-on’ technology to easily monitor and control these three variables.
Sand Flow
Each type of sand addition entering the mixer should be monitored and regulated, such as – new silica sand, reclaimed silica sand and or speciality sand (Chromite, zircon and olivine) additions. These can be regulated either by a precision pneumatic sand selection gates or an electrically actuated gate with infinite aperture control known as a ‘Smart Gate’.
Read more: OMEGA SINTO PROVIDES MIXING TECHNOLOGY FOR ALL FOUNDRIES