Effects of Some Wood Chip Properties on Pulp Quality
A series of TMP experiments were performed at CIPP’s TMP pilot plant, and some pulp properties were measured. By comparing chip and pulp properties, and using projections to latent structures (PLS) analysis, we were able to demonstrate that on-line CMS measurements can be used to predict some pulp properties. It should be pointed out that the focus of this paper is to show how CMS measurements can be used to predict some pulp properties. This prediction will suggest ways to control chip quality so as to ensure pulp quality. We tried to explain some important chip properties included in the measurements, but did not try to model them.
Effects of log position in the stem and commercial thinning on jack pine chip dimensions produced by a chipper-canter
Fifteen stems of jack pine (Pinus banksiana Lamb.) coming from three commercial thinned (CT) plots (control, moderate, and intensive thinning) in the Abitibi-Témiscamingue region, Canada, were cross-cut into three 2.4 m length sections: bottom, middle, and top logs. Logs were processed with a chipper-canter at three cutting widths (CW 12.7, 19.1, and 25.4 mm), producing chips and a three faced cant. Chips were assessed by thickness, width, and length. Knot characteristics [total knot number (TKN) and area (TKA)] were assessed in the three cant faces. Growth ring attributes [earlywood density, latewood density (LWD), ring density (RD), earlywood proportion (EWP), ring width, and rings per mm], mechanical properties (shear, splitting, modulus of elasticity and modulus of rupture in bending), and basic density were evaluated on samples obtained within each CW area. The weighted mean chip thickness (WCT) was significantly affected by the log position in the stem (LPS) and CW. WCT increased as CW increased. Jack pine produce thicker chips than black spruce, when processed under the same cutting parameters. Thickness of chips coming from bottom and middle logs was similar due to a greater taper of the bottom log, which slightly increased this dimension. Thickest chips were produced in the top log due to a higher TKA and TKN towards the top of the stem. Multiple linear regressions showed that TKA, CW, and RD were significant predictors of WCT. Chip size distributions were significantly affected by the CT, LPS, and CW. Thinned stands logs appeared to produce smaller chips than natural stand logs. Moreover, chip thickness distribution was affected primarily by TKA and EWP, while the width and length distribution was mainly affected by EWP, LWD, and TKN. Chip size in jack pine is to some degree determined by knot attributes, growth ring characteristics, and wood density of the raw material. These results suggest the potential advantage of sorting logs prior to chipping, either by species, LPS and/or provenance (thinned or natural stands).
The chromatographic and spectral properties of stilbene derivatives.
Abstract The RF of 26 stilbene aglycones and glucosides have been determined in several systems by means of paper chromatography and thin-layer chromatography. Most stilbenes in paper chromatograms showed a straight-line relationship between RF value and the number of free phenolic hydroxyl groups. The absorption spectra of 28 stilbenes in alcohol with or without added sodium acetate, sodium ethylate and boric acid-sodium acetate have been measured. Interpretations of the spectral changes have been made in terms of the structure of stilbenes which also can be divided into several groups due to spectral changes with added sodium ethylate. The presence of ortho-dihydroxyl groups in stilbene molecules can be detected by the spectral changes with boric acid-sodium acetate.