Alkyl Ketene Dimer Wet End Hydrolysis in Alkaline Hardwood Furnish
Alkyl ketene dimer hydrolysis in alkaline hardwood stock converts active sizing wax into unreactive dialkyl ketone, raising chemical costs and felt deposits.
Whitewater Temperature
Process Thermal State
Thermal energy levels within recirculated paper machine process water dictate fluid viscosity, chemical reaction rates and sheet dewatering behavior. Papermill operators adjust whitewater temperature to optimize drainage performance across the forming wire and wet press sections. Heat input comes from fresh water heating, mechanical energy dissipation and closed loop mill heat integration systems.
Maintaining steady thermal conditions prevents fluctuations in vacuum pressure and moisture profiles across the paper web. Scope limits cover internal process water loops within the wet end prior to primary effluent treatment.
Drainage Efficiency
Higher water temperatures reduce liquid viscosity, accelerating water removal through the wire and vacuum suction boxes. Rapid dewatering allows higher machine operating speeds and lowers steam consumption in the dryer section. Chemical additives like retention aids, sizing agents and strength resins exhibit temperature-dependent activity profiles.
Elevated temperatures increase biological activity and slime formation, requiring targeted biocide additions to prevent sheet breaks. Thermal consistency prevents web expansion or contraction that disrupts sheet formation quality.
System Boundary
Excessive heat levels degrade wet end starch polymers and reduce the solubility of dissolved air, causing foam formation in the headbox. Temperatures exceeding sixty degrees Celsius damage synthetic press felt fibers and accelerate corrosion on stainless steel machine components.