Investigation of the fiber composition effect upon sack paper properties

The article presents data on production volumes of sack paper, which is produced by the world's leading companies. The main raw material for the manufacture of this product is unbleached softwood sulphate pulp having a high cost. In the present research work the fiber composition effect upon sack paper properties was investigated. This makes it possible to determine the optimal mass ratio of unbleached kraft primary fibers (kraft pulp) and seco ndary fibers (waste paper) for the manufacture of sack paper. Doptimal continuous design (Kono, 1962) for the estimating second order polynomial full models was used as the experiment design for the optimization of the pulp fiber composition. Considering the restrictions on the quality parameters speci fied in GOST 2228–81 “Sack paper. Specifications” the analysis of the obtained experimental data using the search function in Mi crosoft Excel 2007 gave the following results on the sack paper fiber composition: kraft pulp content ( X1) – 43.30% of a. d. s.; polyacrylonitrile fibers content ( X2) – 0.15% of a. d. s.; waste paper content – 56.55% of a. d. s. During the experiment it was found that an increase of polyacrylonitrile fibers content from 0.05 to 0.20% in the kraft pulp structure leads to the increase of sack paper tensile strength by 25–28% (breaking length increased from 5,700 to 7,300 m). But paper whiteness at the same time decreased by 9.7%. This made possible to reduce the content of expensive kraft pulp in the composition of sack paper by 27% (taking into account the 30,000 t/year production of sack pa per, saving of kraft pulp can reach 8,000 t/year)

Rapid method for determining the composition of crude alcohol using diagrams composition – property

The preparation of a raw alcohol in a beer still is a periodic process which is accompanied by a flood, the reflux-to-product ratio and speed of sampling changes, unexpected temperature jumps etc. As the result, at formal conformity with the sampling temperature, the main product is polluted by fusel oils. The degree of pollution by fusel oils is above the requirements needed for further treatment which in turn requires an ad-ditional rectification. For this reason the process of periodic rectification needs continuous express control. The rapid method of the determination of the com position of crude alcohol using diagrams composition-properties was developed. There fractive index, the density and su rface tension were chosen as the physical properties characterizing the mixture. The re fractive index was measured on a digital portable refractometer PAL-RI made by the company ATAGO (Japan), the density was measured using a pick-nometer, the surface tension was measured at stallagometеr with a falling drop method. Experimental plan was realized on a simplex la ttice. The third-degree polynomial was used as a model. All calculations were made using the “Simplex” program. The adequate mathematical models (diagrams) were made which allowed us to determine the composition of crude alcohol using only three physical con-stants: density, refractive index, surface tension. Validity check of the model has shown that the error of the results does not exceed 3% rel. (ethanol concen tration) and 7% rel. (fusel oil concentration)