THE RELATIONS BETWEEN NON-STRUCTURAL SUBSTANCES, ANNUAL RINGS WIDTH AND LATEWOOD SHARE IN PINUS SYLVESTRIS L. STEM

Extractives and ash contents, share of latewood and annual rings width were analyzed in wood at different heights and different zones of the Pinus sylvestris L. stem cross-section. Additionally, the high performance liquid chromatography (HPLC) with a conductometric detector was applied to determine the sulphate (SO42-) and hydrogen phosphate (HPO42-) anions concentrations in wood and bark of Pinus sylvestris L. stem. In this paper, based on the results it was observed, that generally extractives content increased in the direction from sapwood perimeter to middle heartwood and pith adjacent heartwood zone. Moreover, the results showed that the greater share of latewood in annual rings the lower ash and extractives contents in the wood, but the higher sulphate (SO42-) and hydrogen phosphate (HPO42-) anions concentration. The sulphate (SO42-) and hydrogen phosphate (HPO42-) anions concentrations in the bark of the Pinus sylvestris L. stem were higher at the top than at the butt-end part

Short notes: A research on the application of industrial by-product calcium sulfate whiskers in paper filling

The basic properties of calcium sulfate whiskers were studied and compared with commercial ground calcium carbonate (GCC) fillers. The modified whiskers were used for paper filling and compared with a commercial precipitated calcium carbonate (PCC). As a result, it shows that when the unmodified calcium sulfate whisker is used to fill the paper, the ash content of the handmade sheet is low because of its dissolution problem. The ash content of the paper increased obviously when the modified calcium sulfate whisker was added, which reached the ash level of PCC filling. In addition, the paper strength increased greatly, but the light scattering coefficient decreased. In addition, the strength property of the modified calcium sulfate whisker filling paper is basically the same as that of the PCC filling paper with 14.99% ash content when the ash content of the modified calcium sulfate whisker filling paper is 21.95%.