Finest work in the chemical industry


Initial Situation

Our customer is a global chemical company and manufacturer of base and speciality chemicals as well as high-performance materials that are used in different everyday products. In the manufacture of highly viscous products in the chemical industry, such as adhesives, insulating components seals, underbody protection etc., Filtration Grup automatic metal-edge filters are often the only technology that provides economical filtration to protect downstream process steps against contamination. In the manufacturing process of MDI (methylene-diphenyl-isocyanate), a raw material for polyurethane, the main task is to retain and separate any possible agglomerates or deposits from the reactor. Isocyanate has almost no lubrication properties, which must be taken into account when designing the bearings. It reacts with substances that demostrate an OH group (e.g. water, also humidity etc.) vis-àvis solid matter.


In this sepcial manufacturing process the products are processed in complex machines and systems, i.e. applied with fine nozzles. Foreign particles and agglomerates of products constituents would lead to malfunctions and product waste here, and in the worst case scenario, cause damage to the machines. In order to guarantee reliable operation for our customers, Filtration Group supplied an automatic metal-edge filter AF 738 with optimised bearing points and a double action mechanical seal that is flushed with white oil (vaseline).

Technical Data

– Medium: methylene-diphenyl-isocyanate (MDI)
– Operating pressure: 10 bar
– Operating temperature: 25 – 40 °C
– Filter fineness: 250 μm
– Volume flow: 35 m³/h


The solution is an automatic metal-edge filter AF 73 S with optimised bearing points and a double action mechanical seal that is flushed with anhydrous white oil (vaseline) . The filter supplied is completely free of lubricants or preservatives. The shaft seal is in compliance with Germany’s “TA-Luft” air quality regulations. To avoid secondary reactions, we ensure no ingress of humidity into the process. The FG automatic metal-edge filter replaces existing basket strainer filters, thus minimising employeess‘ contact with isocyanate.

Customer Value

A great customer benefit is the process safety through efficient filter cleaning and the associated improvement in safety and environmental protection. Further advantages are precision separation using the metal-edge filter principle, cleaning performed without an interruption in filtration and low life-cycle-costs as no filter material is used.

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