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Preliminary Suggestions
| Typical indicators / objective observations | Likely direct causes | Low-cost actions to try first | When you should introduce / re-select PAM | Why PAM is recommended here |
|---|---|---|---|---|
| Uneven sheet / streaks / bundles | Insufficient dispersion; local overflocculation; poor mixing sequence | Improve mixing and chemical addition sequence; check approach flow shear profile | When dispersion control must be stabilized chemically | Proper polymer choice can help control interaction and maintain a stable dispersion state |
| Formation worsens when trying to improve retention | Retention program creates large flocs in low-basis-weight sheet | Rebalance MW/charge; tighten dosage; adjust addition point | When tissue formation is the primary KPI | A controlled program avoids excessive floc size while maintaining capture |
| Runnability drops during speed changes | Wet-end instability; inconsistent chemistry control | Standardize transitions; stabilize charge control and dosing response | When stability during speed-up is required | A robust selection window reduces sensitivity to operational transients |
Applicability boundary: Applicable when dispersion and interaction control are primary levers. If non-uniformity is dominated by mechanical distribution (headbox, turbulence generator, stock approach issues), correct mechanical causes first.
Selection guidance: how to choose the right PAM for this papermaking scenario
Molecular weight (MW): retention strength vs. formation risk
Higher MW can increase bridging and retention of fines/fillers, but excessive floc size may harm formation and sheet uniformity. The best MW window depends on machine shear in approach flow and your target balance (retention vs. formation vs. drainage).
Charge density (cationicity): wet-end is a charge-controlled system
Charge density governs how PAM interacts with negatively charged fibers, fines, and fillers. Too low may underperform; too high or overdosing may create soft flocs, deposit tendency, or drainage swings. A practical program keeps the system in a stable charge window.
Cationic vs anionic vs nonionic: selecting the ionic type
For wet-end retention and drainage improvement, cationic PAM is commonly used as a retention/filter aid. Anionic or nonionic grades may be relevant in specific sub-systems (for example, certain coating or dispersion control tasks) depending on the chemistry regime.
Emulsion vs powder: choosing by control and response speed
Powder grades can be economical for stable operations with disciplined solution preparation. Emulsion grades can be preferred when fast response and more automated dosing are required. Choose based on your make-down capability, staffing, and control needs.
Initial recommendation
Starting point: Treat this as a dispersion/interaction-control problem: select a polymer program that prevents harmful micro-flocs while preserving necessary retention. Validate by formation uniformity and runnability, not only by retention numbers.
Contact us for a precise grade recommendation
A precise recommendation requires real wet-end data. Please submit the form and include the items below (ranges/estimates are acceptable if exact values are unavailable). We also welcome complex or rare cases.
- Tissue grade and basis weight: Lower basis weights are more sensitive to micro-flocs and overflocculation.
- Furnish composition and refining level: Affects fiber interaction strength and dispersion demand.
- Approach flow shear profile: Determines whether micro-flocs persist or break.
- Current retention/dispersion additives: Interactions can create streaks or instability.
- Target KPI (formation, softness, runnability): Keeps optimization aligned with product requirements.
- Problem repeat probability: Guides selection for stable operation across transitions.
What you will receive: recommended PAM type/form, 2–3 candidate grade windows, an initial dosing range for a controlled trial, and step-by-step guidance for a practical machine-side validation.
