A guide to eliminating baggy webs

Slack or baggy webs can cause misregistration, wrinkles, and breaks in printing and converting operations. Bagginess appears as non-uniform tautness in the cross direction (CD) of a paper web. The underlying cause is uneven CD tension profiles, for which there are few remedies once the paper is made. Precision measurements of CD tension profiles combined with trials on commercial paper machines have shown that uniform CD distribution of moisture, basis weight, and caliper profiles at the reel are key to avoiding bagginess. However, the most important but infrequently measured factor is the CD moisture profile entering the dryer section. Wetter areas entering the dryers are permanently elongated more than dry areas, leading to greater slackness in the finished paper. In storage, wound-in tension can amplify baggy streaks in paper near the surface of a roll and adjacent to the core. Unwrapped or poorly wrapped rolls exposed to low humidity environments may have baggy centers caused by moisture loss from the roll edges. All of the factors that impact bagginess have been incorporated in a mathematical model that was used to interpret the observations from commercial trials and can be used as a guide to solve future problems.

Characterization and Thermal Behavior Study of Biomass from Invasive Acacia mangium Species in Brunei Preceding Thermochemical Conversion

Acacia mangium is a widely grown tree species across the forests in Brunei Darussalam, posing a threat to the existence of some native species in Brunei Darussalam. These species produce large quantities of lignocellulosic biomass from the tree parts comprising the phyllodes, trunk, bark, twigs, pods, and branches. This study examined the thermochemical characteristics and pyrolytic conversion behavior of these tree parts to assess the possibility of valorization to yield bioenergy. Proximate, ultimate, heating value, and Fourier Transform Infrared Spectroscopy (FTIR) analyses were performed to assess the thermochemical characterization, while thermogravimetric analysis was conducted to examine the pyrolytic degradation behavior. Proximate analysis revealed a moisture content, volatile, fixed carbon, and ash contents of 7.88–11.65 wt.%, 69.82–74.85 wt.%, 14.47–18.31 wt.%, and 1.41–2.69 wt.%, respectively. The heating values of the samples were reported in a range of 19.51–21.58 MJ/kg on a dry moisture basis, with a carbon content in the range of 45.50–50.65 wt.%. The FTIR analysis confirmed the heterogeneous nature of the biomass samples with the presence of multiple functional groups. The pyrolytic thermal degradation of the samples occurred in three major stages from the removal of moisture and light extractives, hemicellulose and cellulose decomposition, and lignin decomposition. The bio-oil yield potential from the biomass samples was reported in the range of 40 to 58 wt. %, highlighting the potential of Acacia mangium biomass for the pyrolysis process.

Biochemical analysis of Five Dried Fish species of Bangladesh

To assess the proximate composition, five dried fish samples of Mystus vittatus, Channa punctatus, Chanda nama, Corica soborna and Trichuirus haumela were selected. The moisture content ranged from 14.06% to 24.58%, protein varied between 44.08% to 65.65% (moisture basis) and 53.45% to 76.39% (dry matter basis), lipid content of the selected dried fishes ranged from 1.91% to 17.76% (moisture basis) and 2.31% to 21.54% (dry matter basis). Ash content varied from 9.63% to 22.73% (moisture basis) and 11.21% to 28.15% (dry matter basis). The experiment was replicated three times and conducted from February, 2009 to August, 2009. Samples were collected from Sayedpur Upazaila, Nilphamari District, the north-west region of Bangladesh.DOI: http://dx.doi.org/10.3329/ujzru.v31i0.15373Univ. j. zool. Rajshahi Univ. Vol. 31, 2012 pp. 09-11

EFFECT OF IMMATURITY ON THE MILLING AND BAKING QUALITY OF RED SPRING WHEAT

Red spring wheat, grown in four separate years at a Manitoba location, was cut at various stages of maturity, allowed to dry in the ear, threshed and subjected to milling, analytical, rheological and baking tests in order to determine the effect of immaturity on end use quality. Moisture content in the ripening wheat fell steadily, from a level of 55–75% (depending on the year) around 10 days following anthesis to 15–25% around 40 days following anthesis. Patterns of changes in quality data were more closely related to moisture content at cutting than to number of days from anthesis. Maximum test weight and grade were usually obtained for wheat cut at a moisture content of 45% or lower, whereas maximum dry weight was not achieved unless kernel desiccation was allowed to continue to 30–35% moisture. Wheat protein content (13.5% moisture basis) reached a minimum at about 50% moisture (around 15–28 days following anthesis) then increased by 0.5–1.3 percentage units to its final value at full ripeness. Acceptable milling quality was achieved when wheat was allowed to ripen to about 47% moisture before cutting although a further slight improvement was noted with further ripening. Flour-damaged starch content tended to decrease steadily with increasing maturity and this resulted in a decrease in flour Farinograph water absorption with increasing maturity. Physical dough characteristics indicated an increase in gluten strength with increasing maturity as manifested by increases in dough development time and extensigram area. Loaf volume was at a normal level for the protein content for all but the most immature samples although crumb color, as flour color, was poor for samples cut above 47% moisture.

EFFECTS OF HIGH RATES OF NITROGEN ON NEEPAWA WHEAT GROWN UNDER IRRIGATION II. MILLING AND BAKING QUALITY

Forty-one composites of a hard red spring wheat (Triticum aestivum L. cv. Neepawa), grown under irrigation in five fertilizer trials at four locations in Southern Alberta over a period of 3 yr, were subjected to milling, baking and allied tests. Very high protein content (e.g. over 17% on a 13.5% moisture basis) was associated in several instances with a marked weakening of physical dough characteristics and a deterioration in baking quality. Quality data from commercial railway carlots of Canadian red spring wheat were used to put the fertilizer study results into perspective and to show that although certain combinations of high nitrogen fertilizer application with location, cultivar and growing conditions may cause undesirable deterioration in baking quality, this is unlikely to cause problems in cargo quantities of wheat.