I recently sat down with Scott Borges to learn about roll cleaning systems. Scott is the Product Line Manager – Doctoring for Kadant Solutions Division. Scott has worked for Kadant Solutions for 18 years and provides doctoring and roll cleaning support to the organization’s District Sales Managers.

V: Where did the term “doctor” originate in the paper industry?

S: It’s believed the term “doctor” originated in the early 1900’s by an engineer named Dr. Vickery. He invented the paper machine doctor and the term “doctor” came from his title. Dr. Vickery observed water on roll surfaces as well as fiber accumulation which limited paper machine speed and runability. The doctor blade was invented to remove this excess water and fibers from the roll surface. 

V: What is a doctoring roll cleaning system?

S: Doctoring or roll cleaning is an important process that has several basic functions such as removing water and contaminants from the roll surface, cleaning and conditioning the roll surface, and sheet shedding during sheet breaks or threading operations.

V: What components make up a doctoring roll cleaning system?

S: A doctoring roll cleaning system consists of the doctor back (i.e., a beam), a blade holder, a blade, and components to mount the system to the machine’s framework.  The blade is the component that performs the functions of removing water, debris, and contaminants; cleaning and conditioning the roll surface, or shedding the sheet. Blades wear out over time and need to be replaced on a regular basis depending on the application. 

Blade material selection is critical for the application, but the other components of the system are just as important to the system’s success.  You can utilize the most optimal blade material yet have poor performance if the doctoring system is not adequate for the application. 

V: What are some benefits of doctoring roll cleaning?

S: Doctoring can prevent material from wrapping the roll surface. In applications where a continuous web of product is being produced such as paper, film, fibers, or food, a web break can cause the material to wrap around the roll.  Doctoring systems help direct the product, sheet, or web to the next section of the machine. There are also specialty doctoring applications like creping of the sheet, coating, and metering applications.