The use of vertical and horizontal mixing systems in bulk material technology and mechanical process engineering has been known for many years and is used in almost all known production processes and materials. However, it is the specific detailed solutions and machine equipment that enable an application-specific adaptation to the manifold requirements.
Different processes are used today to produce a homogeneous and stable premix from the individual raw materials. Depending on the further processing route, the components are either mixed homogeneously by mechanical means to form a “blend” without thermal treatment. Vertical, horizontal and heating/cooling mixer combinations have proven themselves worldwide in the plastics and chemical industries.
Our customer is an internationally operating company and offers a universal product portfolio of high-performance mixing systems for batch processes in all mechanical and thermal processes for the preparation of additive compounds. Moisture and fiber properties place the highest demands on the aspiration system of the heated mixer. Filtration Group has selected filter elements in conical design for this application with a separation efficiency of 99.99 % at 0.3 µm and a vapor permeability even at the very high processing temperatures required. The round design of the dust collector used and the piping are insulated and electrically heated to effectively prevent premature condensation. A few degrees before the final temperature is reached, the mixer interior is switched back to atmospheric venting, the filter is cleaned again and filter residues of the mixture are thus returned. The filter elements through which the air flows ensure the required degree of separation and combine good hydrolysis resistance with high permeability to moisture at temperatures of 150 – 160 °C – unlike conventional filter materials, which tend to block degassing.
This solution has thus considerably extended the processing window compared to the single-stage process with regard to the moisture content of the fibers.