Size Press and Coater

Rod Metering Size Press


The Coater and Size Press are used for applying starches, pigments, or chemicals to the surface of the product. The chemicals applied can be used to strengthen the product or to improve the printing quality of the product or even to improve the softness of the product.

  1. Improve strength, surface, and/or printing properties of paper & board.
  2. Add pigments to the surface of the web.

Additional Information

Here are a few examples of the purposes for the different chemicals or pigments used in Coater/Size Press:

  • Linerboard - Uses starch to improve the stiffness and/or strength of boxes.
  • Magazines/Newsprint - Uses pigments & binders to enhance printing characteristics.
  • Copy Paper - Uses pigments & binders to enhance printing characteristics when using personal printers.
  • Packaging/Containers -Use coatings to minimize shipping damages and to create water barriers.

There are distinctions between Coaters and a Size Presses in their operation. These two categories can be summed up as such:

  • Coaters

    Coaters generally indicate that coating is being applied to the web surface. The coating is generally defined as having pigments & binders along with many other chemicals. A simplified example of coating is common latex house paint. Historically paper machinery coaters have used a metering device to control the amount of coating applied to the web.

  • Size Presses

    Size presses are generally defined as transferring a film from a roll to the web. There is a wide variety of films applied with size presses. They range from water to corn starch at ~10% solids, to coating at 64% solids to many other chemicals & solutions at varying solids.