Metal ion contaminants from wood pulp, chemical additives and processing equipment can cause adverse effects in the paper making process. Lower bleach efficiency results when metals (Fe3+, Cu2+, Mn2+, Al3+) catalyze decomposition of bleach chemicals. Brightness reversion can be induced by the presence of iron. Both peroxide and hydrosulfite bleaching can be assisted by the use of gluconate based chelating agents.
Sodium Gluconate use is increasing in the paper industry both as a single chelant and in combination with other chemicals, i.e. EDTA, DTPA, etc. The big advantage associated with sodium gluconate is its effectiveness under alkaline conditions and its biodegradability. The “Green Revolution” is forcing a review of the long term impact of using various chemicals. Gluconates are very environmentally and do not contain any nitrogen or phosphorous compounds.