Reducing friction between metal and thermo-mechanical pulp using alkyl ketene dimers and magnesium stearate

The friction between natural fibers and metal affects tool life, wear and tear and surface defects of extrudates. The ability of alkyl ketene dimer (AKD) and magnesium stearate (MgSt) to reduce coefficient of friction (COF) between thermomechanical pulp (TMP) and metal were determined at temperatures of 30, 100, and 180 degrees C and additive concentrations from 0.5 to 5 wt%. The AKD and MgSt were added to TMP sheets through spraying, followed by drying. ATR-FTIR and IR microscopy confirmed the presence of AKD and MgSt on the TMP. AKD addition at 2 wt%, consistently reduced the COF of TMP and metal, whereas MgSt reduced COF at 100 and 180 degrees C, only. No further reduction in COF was observed at 5 wt% of AKD or MgSt.