Quick answer
PolyDADMAC is mainly a fixative and charge-control agent in papermaking. By neutralizing anionic trash, it can reduce interference with retention aids and help stabilize retention, white-water clarity and drainage. Grade, dose and addition point must be confirmed on the mill's actual furnish.
Papermaking wet-end systems contain fibers, fines, fillers, dissolved substances and process additives that continuously change the charge balance. PolyDADMAC is used as a strongly cationic charge-control polymer to neutralize anionic contaminants and stabilize the wider wet-end chemical program.
The role of PolyDADMAC in wet-end chemistry
Anionic trash from recycled fiber, wood extractives, coating broke and dissolved organics can consume cationic retention aids before they reach useful adsorption sites. PolyDADMAC helps fix dissolved and colloidal substances to fibers and reduces interference with downstream additives.
Potential effects on retention and drainage
Better charge balance may support more stable first-pass retention, cleaner white water, improved drainage or lower chemical-consumption variation. Results still depend on furnish, conductivity, pH, filler loading, shear and the complete retention program; PolyDADMAC is not a stand-alone guarantee.
Addition-point and trial data
Possible trial points include thick stock, the machine chest and selected approach-flow locations. Useful data includes paper grade, virgin or recycled furnish ratio, pH, conductivity, cationic demand, filler type, retention system, present dosage and the main operating problem. PD J41 and PD J45 are practical starting grades, followed by furnish-specific comparison.
Frequently asked questions
Is PolyDADMAC a retention aid?
It is mainly used for charge control and fixation, but improved charge balance can support the mill's retention and drainage program.
Which grades are starting points for papermaking?
PD J41 and PD J45 are common starting points, followed by furnish-specific comparison and dosage optimization.
Can PolyDADMAC be used with CPAM or microparticle systems?
Yes, but compatibility, addition sequence and dosage should be confirmed through laboratory and mill trials.