Mechanical Force
Forces exerted by rotating elements in a pulping vessel define the energy intensity required to separate individual fibres from a consolidated sheet. Engineers calculate rotor shear stress based on the torque applied by the motor and the surface area of the blades in contact with the stock. This measurement describes the friction and pressure changes that break the hydrogen bonds holding the paper together.
It governs the speed at which a dry bale is converted into a pumpable liquid.
Pulping Action
Interaction between the rotor and the suspension creates localized zones of high turbulence. Within these zones, rotor shear stress must be high enough to penetrate coated surfaces or wet-strength resins. Low values lead to the formation of unpulped lumps that clog the discharge grates.
Adjusting the distance between the rotor and the extraction plate allows for the fine-tuning of this force.
Damage Threshold
Excessive intensity during the pulping cycle can lead to the fragmentation of contaminants into smaller particles. If rotor shear stress is not managed, brittle plastic films may turn into microplastics that are difficult to remove in later stages. Operators monitor power consumption to keep these forces within the design limits of the machine.
