Monitoring Product Viscosity For Resins Manufacturing

An expert in the field of chemical engineering offers advice to resin manufacturers.

QUESTION: We produce many types of synthetic resins in our coating plants, and for each type we must comply with several formulations. Is there an easier, more reliable way to monitor product viscosity and determine the end of a reaction other than classical manual sampling and laboratory testing?

ANSWER: There are reactor-mounted viscometers with probes inserted in the reactor. Generally, they are unreliable because of inaccurate temperature measurements and interference with nitrogen bubbles or solid particles in the reactor contents.

The best and most accurate way to monitor viscosity is through online continuous viscosity measurement, where a small quantity of product is circulated through a viscometer mounted in an independently temperature-controlled enclosure near the reactor.

Such a system is used for alkyd, polyester, epoxy resins and polycondensation reactions. It presents several advantages, including the following.

  • The signal generated by the viscometer is directly correlated to the product viscosity. It represents a real-time measurement and is a reliable way to monitor the reaction process.
  • This viscosity monitoring can be made at temperatures different from the reactor temperature, thus allowing flexibility with instrument calibration and selection of the viscosity range.
  • The end of the reaction can be exactly determined, thus eliminating off-spec product and waste.
  • The process can be entirely automated, thus reducing batch time and operating costs.
  • Product quality as endpoint viscosity can be achieved for each formulation.

Disadvantages to online continuous viscosity measurement are as follows.

  • To operate the system, a flanged connection must be available or installed on the lower section of the reactor. This may not always be an option with existing equipment.
  • The system is limited to resin manufacturing reactions where viscosity evolves during the batch and represents a valuable parameter to monitor.

Bernard Seguy is President of RHE America. He holds a Master's Degree in Chemical Engineering from the University of Lille in France.

For more information, contact RHE America, 2525 Cabot Drive, Suite 205, Lisle, IL 60532; phone (630) 577-0400; fax (630) 577-0401; e-mail; or visit

Did you enjoy this article? Click here to subscribe to Adhesives & Sealants Industry Magazine.

You must login or register in order to post a comment.



Image Galleries

ASI April 2014 Photo Gallery

Our April 2014 issue is now available!


ExxonMobil Tackifier Expansion

Dwight Tozer, vice president of ExxonMobil’s Adhesion Industry business, discusses the company’s latest tackifier expansion project with Editor-in-Chief Susan Sutton.

More Podcasts

Adhesives & Sealants Industry Magazine

ASI march 2015 cover

2015 March

Welcome to our annual Raw Materials, Chemicals, Polymers and Additives Handbook!
Table Of Contents Subscribe

Paid Leave

President Obama recently announced he wants U.S. businesses and the federal government to provide paid sick leave and paid parental leave to all workers. Do you think this is a good idea?
View Results Poll Archive


Handbook of Sealant Technology

The Handbook of Sealant Technology provides an in-depth examination of sealants, reviewing their historical developments and fundamentals, adhesion theories and properties, and today’s wide range of applications.

More Products

ASI 2014 Buyers GuideASI's Buyers' Guide

Annual purchasing resource for equipment used in the manufacture/formulation of adhesives, sealants, pressure sensitives, tapes and labels and for application of finished adhesives. 


facebook_40px twitter_40  youtube_40pxlinkedin_40 google+ icon ASI 30px

Clear Seas Research

With access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.