Measuring concentration in paper sizing process

Measuring concentration of sizing liquid in the preparation and size press 

In papermaking, sizing provides paper a desired degree of resistance to water or other fluids and increases surface strength. Vaisala K-PATENTS® Process Refractometers are used for precise concentration measurement and control of sizing liquids in the internal sizing, surface sizing and coating processes. 

The control applications are in:

  • Sizing liquid cooking where the cooked starch, CMC or PVA is diluted with water to the desired concentration before storage.
  • Size press or blade coater where concentration levels vary in the size press circulation system. The paper absorbs more water than sizing material and this changes the concentration of the liquid to the recirculation line. Therefore, water must be added into the circulation to maintain the dilution levels.

Accurate concentration measurement ensures tight concentration specifications of the sizing liquids and helps to stabilize sizing conditions and paper quality.

Applications in the pulp and paper processing

The efficiency and safety of Kraft chemical recovery and fiberline and brown stock washing processes can be significantly improved by measuring in-line, real-time dry solids content. Download our application notes for more information.

Liquid concentration measurement

Vaisala offers a wide range of products tailored to liquid measuring needs of different industries. Learn more about the refractometer technology and its applications, and visit the library of product related assets.