Problem Summary

Regardless of grade or machine configuration, reducing levels of unretained wet end additives as well as collateral damage inflicted by them can make a tremendous difference in machine operation.  Optimizing the mix and feed rates of wet end chemistries can be a daunting task, especially if many grades are involved.  One obstacle to wet end simplification is the sheer number of additives in a typical wet end that are needed to achieve various properties.  It is not uncommon to run 5–10 different additives simultaneously.  Understanding the purpose of these additives is easy; however, determining how they affect the sheet and interact with other chemistries is much more complex.  Chemical inefficiency, high additive cost, machine deposition, foaming, and poor runnability are all results of a less-than-optimum wet end.

Recommended Solution

Simplification of the paper machine wet end is a key benefit of Hercobond® 6000 paper performance technology.  This one-component technology allows the papermaker to drastically reduce the number and usage of traditional additives.  Multiple benefits have been documented including strength, drainage, retention, charge control, deposit control, and foam reduction. 

Introducing one of the Hercobond 6000 series products into a papermaking system will change the operating dynamics of the wet end.  The overall system charge profile shifts toward cationic as larger quantities of fines and anionic trash are held and fixed into the sheet matrix.  As a result, other cationic chemistries such as starch, coagulants, and retention aids become more efficient, and significantly less dosage is required.  This clean-up creates a beneficial “spiral effect” that cycles through the system loop and back through the paper machine allowing further optimization.  This phenomenon is possible due to Hercobond 6000’s ability to provide strength, retention, and drainage properties along with high cationic charge.  Effective additive usage and a clean wet end are not the only benefits associated with running this technology.  Other, less tangible benefits include decreased deposition and picking, reduced dryer steam usage, and reduced load on the effluent plant.

Key benefits recorded from commercial applications of Hercobond® 6000 paper performance technology:

Simplified, clean, wet end
Reduced/improved additive use (starch, strength aids, retention/drainage aids, size, defoamers, charge donors)
Improved machine runnability – less deposition and breaks
Improved sheet strength
Increased drainage, machine speed, and production