Effect Of Counter Blades On Paper Properties: Newsprint, 2006 Papermaker’s Conference

In this report, we summarize the effect of counter blades in the former of a pilot machine on the physical properties of newsprint. The variables in counter blade applications include loading intensity, the number of counter blades and their positions. The effects of these variables on formation, tensile strength, porosity, Scott internal bond, drainage and fines retention are addressed. We found that counter blades improve formation if properly applied. The number of counter blades had the following effects on sheet properties: two counter blades improved formation, the third and the fourth counter blades improved formation marginally, but the fifth counter blade impaired formation. The application of more than three counter blades decreased the tensile strength and Scott internal bond strength. The sheet also became more porous. We also demonstrated that counter blades must be positioned strategically with reference to sheet consistency. The positive influence of counter blades on sheet properties appeared to depend on the consistency at which the counter blades were applied. The effect of loading intensity was also examined. The best formation results were demonstrated with very gentle loading.