Tissue Machine Refining

Refining is one of the critical process steps in engineering the structure of tissue as it has a major influence on fiber quality. Refining mechanically alters the fibers by brushing, hydrating, and cutting them. These actions increase the flexibility and total surface area of the fibers. The result is more area available for bonding which directly affects sheet strength, formation, and many other properties. This course will describe refining actions as they relate to disc refiners. Other refiner types will have very similar actions and results.

•Describe the effects of refining on wood fibers •Describe safety precautions associated with refiners •State the objectives of refining •Identify the different refiner types •Explain how refiner plate design and gap affect tissue sheet properties •List the different refiner control strategies •Explain the effects of over-refining