FIBER CHARACTERIZATION USING CONFOCAL MICROSCOPY - THE EFFECTS OF RECYCLING

The effects of laboratory recycling on the transverse dimensions of fi bers of three softwood pulps-a TMP, a CTMP, and a kraft-have been dete rmined with confocal microscopy and image analysis. From the decrease in lumen area and increase in the degree of collapse, the mechanical p ulp fibers appear to flatten upon recycling. However, this did not occ ur for the chemical pulp fibers as they were mostly collapsed to start with. These results agree with previous findings on these samples tha t recycled mechanical pulp fibers, in contrast to chemical pulps, tend to give a denser and stronger sheet. Recycling decreased fiber wall c ross-sectional area. Although fiber wall thickness also decreased, it was significant only for TMP.