The widely used aminoplasts are produced by polycondensation of formaldehyde either with urea (urea resins, UF for short) or with melamine (melamine-formaldehyde resins, MF for short), which is technically obtained in large quantities from urea in preliminary processes. The process for obtaining these resins is very similar in each case: When pre-filtered urea solution is added to the formaldehyde solution, viscous UF urea resin is produced in a polycondensation reactor in an acidic environment, which is used as wood glue in chipboard production, for example. Melamine-formaldehyde resins (MF) are used for thermosetting plastics with high hardness and abrasion resistance - for example for electrical insulation or switch parts or tableware. The production process here involves the intermediate product hydroxymethylmelamine, which is obtained by adding formaldehyde to melamine at low temperatures in an aqueous solution. The final curing of the MF resins usually takes place downstream by adding fillers via polycondensation at temperatures of around 100 °C, mainly with the aid of acidic catalysts. A cross-linked duromer is then formed by splitting off water and formaldehyde.

KROHNE has an extensive portfolio of measuring instruments for the process production of aldehyde derivatives, such as aminoplasts, combined with many years of experience in this sector. To optimise the correct molar ratio of formaldehyde and urea for polycondensation, reliable pressure measurement in the feed, continuous MIN/MAX level monitoring and precise temperature measurements in the reactor are essential. Here, KROHNE contributes proven vibration level switches, highly developed radar level measuring devices and tried and tested resistance thermometers.