- Inline measurement, 119 readings
- Reference determinations by the plant laboratory, 7 samples
- Rapid-rise zone, from approximately the 43rd minute
One industrial batch of UF/MUF resin, July 2026, approx. 70 minutes. Inline reading every approx. 35 s (119 points), alongside 7 reference determinations performed by the plant laboratory on the same batch. Viscosity values in process units of the installation. Hover the cursor over the chart to read a single point.
Client context
In the production of amino resins (UF, MUF), viscosity increases as polycondensation progresses, and the moment of reaction termination determines batch quality and safety. Offline measurement reflects the state from several to over a dozen minutes earlier, which, given fast kinetics, can be too late.
Delayed reaction termination risks uncontrolled viscosity growth, batch loss, and reactor blockage. The manufacturer required a product reference and reaction endpoint time indication for process control.
Challenge.
- The reaction endpoint was assessed via manual offline rotational viscosity measurement, with information delay (dead time).
- Risk of gelation and reactor blockage if cooling is initiated too late.
- Manual sampling from a hot reactor exposes workers to formaldehyde vapors.
- Lack of parameter repeatability between batches.
Solution
The Spectrally™ X1 with an immersion probe tracks polycondensation progress directly in the reactor. In the feasibility study, we developed a preliminary measurement procedure for a product reference and reaction endpoint indication.
For operation in the dense reactor medium, the probe utilizes a self-cleaning, retractable module (Retractex): it periodically retracts from the medium, flushes the optical window, and returns to measurement, maintaining a stable signal without manual cleaning during the batch.
Results
| Metric | Result |
|---|---|
| Polycondensation reaction endpoint | Preliminary inline procedure developed (feasibility study, partial result) |
| Benefit | Avoidance of gelation and reactor blockage, batch repeatability |
| Current method (offline) | Manual sampling + rotational viscosity, dead time on the order of over a dozen minutes |
Feasibility study result; client anonymized.
What this means for your process
If you conduct batch polycondensation of UF/MUF resins, inline reaction endpoint indication allows you to hit the process window, avoid gelation, and stabilize quality between batches, instead of controlling based on delayed laboratory viscosity.
The most reliable path to verification on a specific process is a pilot trial preceded by a short feasibility study.
