· Background and Challenges:

·The mill produces high-strength corrugated paper using 100% domestically produced OCC as raw material.

·The pulp quality fluctuated significantly, and charge neutralization was difficult due to the low local water hardness.

   ·The goal was to increase tensile strength and compact strength (CCT) while reducing steam consumption   (i.e., improving drainability).

· Solutions:

   ·A synthetic microparticle retention system combining nanosilica and CPAM was adopted.

·This system is less sensitive to charge fluctuations than bentonite systems and is more robust in environments with high anionic interference.

  ·The using point was optimized to ensure optimal reaction between CPAM and nanosilica before the headbox.

·Performance Data:

      ·Drainage Performance: Dewatering efficiency at the vacuum roll was improved, wet paper dryness was increased by 1.5%, and steam consumption in the corresponding section was reduced by 8%.

     · Strength: Due to more uniform retention of fine fibers and fillers and improved fiber bonding, the CCT was increased by 10%.

    · Ash Content: While maintaining the same strength, more inexpensive fillers can be added, resulting in a   steady increase in ash content of 2%, reducing the cost per ton of paper.

  · Wire Cleanliness: Wire life was extended, and the cleaning frequency was reduced.