What changes occur to raw materials during the paper making process?

Answer 1

Papermaking is a series of physical and chemical changes. The physical and chemical changes will depends on raw material used and grade of paper manufactured. For a typical north American paper mill which uses wood for making copying paper, following changes will take place. Operation Type of Change Logging Physical Barking (Removal of bark) Physical Chipping Physical Screening Physical Cooking Chemical Washing Physical Chemical Recovery Chemical Bleaching Chemical Washing Physical Refining Physical Sizing Chemical & Physical Screening Physical Cleaning Physical Wet-end chemical addition Chemical & Physical Sheet Formation Physical Pressing Physical Drying Physical Calendaring Physical Winding Physical Rewinding Physical Cutting Physical