New Paper Machine Gard(TM) screening concept for improved paper quality and paper machine efficiency

Gard(TM) screening involves high consistency screening of mixed stock fed to the paper machine. The objective is to provide effective protection for the paper machine with very fine-slotted screens. This concept provides significant improvement in paper machine operations compared to the conventional machine screening systems. Narrow slotted screens have been used already for some years in recycled fiber and mechanical pulping screening applications. However,the consistency is typically in low 0.7-2% range. Sunds Defibrator has developed a new high consistency DeltaScreen(R) to operate at high consistencies of 3.0 to 4.0% with high reduction efficiencies. The DeltaScreen(R) allowing the use of very fine slots of 0.1-0.35 mm is the heart of the Gard system thus providing an efficient barrier screening for eliminating even the smallest elements of contamination. Sunds Defibrator has delivered already over ten Gard(TM) screeening installations. The paper discusses the improvements of paper quality and paper machine efficiency in line paper, newsprint and board applications.