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Summer 2007 Newsletter ‘ZETA NANO’ Wal-Mart 360 Sustainable Packaging Initiative	John Penniman
Homogeneity Nanotechnology requires that chemicals and stock be dispersed to a molecular state and charge-neutralized. The energy available through conventional mixing is not sufficient to this purpose. Two additional conditions must also apply: The spreading coefficient must be increased by reducing the surface tension below 24 dynes/cm^2. The addition of ionically polar molecules must be accompanied by control of the ultimate zeta potential at zero mV. In the first instance, chemical usage is typically reduced by 1 or 2 orders of magnitude. In the second, about 1 order of magnitude savings is realized. The benefit is very large: on a large machine that consumes, for example, 3$/ton of a particular chemical, or $600K/year, the chemical cost can be reduced to as little as $600/year. The ‘ZETA NANO’ process accomplishes this by use of a catalyst and neutralization of the repulsive surface charge, accompanied by major collateral benefits. Maximum retention, drainage and formation are achieved. Productivity can be maximized. Quality can be maintained at the highest level. Functional and Process Chemicals Chemicals that improve physical properties are added first, and integrated via catalytic homogenization, prior to addition of process chemicals. In a second step, prior to the headbox, a positively charged, or “cationic” chemical is added to the stock until the entire system becomes positively charged, typically in a zeta potential range of +5 to +10mV zeta potential. A negatively charged or “anionic” nanoparticle is then introduced, in amount sufficient to reach a final charge of precisely zero zeta potential. Creation of a charge-neutral system in this manner enables maximum retention, drainage and formation to be simultaneously attained. Current practice lacks the capability of measuring or controlling charge and partially substitutes a “retention aid”, sharply degrading retention, drainage and formation. Water Removal Increased water removal occurs in five different ways: At the wet end, it is enhanced by formation of a nanoparticulate structure which facilitates water removal by gravity. In the press section, it decreases water re-wetting on high speed machines (the higher the speed the better; cylinders don’t work.) Press section efficiency is increased. Dryer section efficiency is increased by as much as 20%. Negative influence of hydrogen bonding is decreased. Conclusion: Implementation of nanotechnology entails achieving homogeneity. Precise neutralization of the repulsive negative charge is the second key step in activating and maximizing powerful intermolecular forces. The greatly reduced need for both chemicals and water removal energy results in a proportionately increased, very large sustainability.
John G. Penniman
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