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.
Cationic Starch Emulsion
Wet-End Retention
Hydrophilic polymer suspension introduced during paper formation acts by neutralizing negative charges on cellulose fibres. Cationic starch emulsion bridges microscopic suspended solids within the aqueous slurry to promote agglomeration and subsequent capture on the moving wire. Electrostatic attraction drives this deposition mechanism because quaternary ammonium groups attached to the polysaccharide backbone possess permanent positive charges.
Starch macromolecules adhere directly to anionic surfaces of bleached kraft pulp without requiring external coagulants when system pH remains between four and eight.
Drainage Efficiency
Mechanical water removal at the forming table accelerates because flocculated fines create a more open sheet structure with higher permeability. Production speeds increase on high-speed paper machines since faster dewatering prevents wet line displacement and reduces dryer section steam demand. Molecular weight distribution governs the rate of floc formation, where excessive shear forces inside pressure screens degrade polymer chains and diminish retention performance permanently.
Sheet formation quality decreases if polymer dosage exceeds optimal stoichiometric thresholds because over-flocculation generates dense clusters that leave pinholes in lightweight packaging grades.
Surface Strength
Dry tensile properties improve after consolidation because starch residues bond adjacent fibres together through hydrogen bonding networks across the inter-fibre matrix. Internal bond strength measured via z-directional tensile testing rises proportionally with retained starch concentration up to the saturation limit of the fibre network. Starch retention uniformity prevents localized stiffness variations that cause converting failures during corrugated medium fluting or folding carton creasing operations.
Converting performance relies on this internal bonding capacity to prevent delamination during high-speed flexographic printing runs.