Search

This study analyzed the effect that pulp fibers have on the surface softness component of hygiene paper. The surface softness component has more of an influence on the evaluation of subjective softness results than the bulk softness component. Using the surface softness measurement technique, this study aimed to evaluate the effect that fibers have on the softness of hygiene paper substrate via objective numerical values to measure the surface softness component of hand sheets composed of various pulp species. The results indicate that coarseness effects had the largest effect on softness among the various fiber characteristics, such as average fiber length, width and coarseness. As fiber coarseness increased, a rough surface formed, which resulted in an increase in the mean deviation from the average friction (MMD). Nonwood fibers had long fiber length and low coarseness, which enables the production of hygiene paper with high strength and softness. This study hopefully could lead to the development of various process technologies that may improve the softness of hygiene paper products. [ABSTRACT FROM AUTHOR]

With the increase in demand for wood and wood products, there is need to find alternative sources for the production of pulp and paper. Non wood plants have attracted interest due to their short growth cycles, moderate irrigation and fertilizer requirements and low lignin content. This study aimed at investigating the fibre characteristics of Agave sisalana for pulp and paper production. Leaves were collected from three sisal plant stands in Oyo State, Nigeria. The plant whorl was divided systematically into bottom, middle and top from which five leaves were randomly collected from each whorl position. The fibres of the leaves were extracted from which 2cm of fibres were taken from three positions on the leaf (top, middle and base). Extracted fibres were macerated and 3375 fibres were measured. The result shows that the fibre length of sisal increased with increasing length of the leaves from base to top with a mean value of 1.68mm. The fibre diameter and cell wall thickness averaged 16.98µm and 2.32µm respectively decreasing from the stem base to the top. The slenderness ratio averaged 99.4 while the coefficient of flexibility averaged 72.61. The highest value of the runkel ratio of Agave sisalana was 0.42. The fibres from sisal (Agave sisalana) leaves possess good fibre dimensions and derived values which will make it suitable for the production of high quality paper. [ABSTRACT FROM AUTHOR]

The article examines the power consumption distribution in the first and second stages of a thermomechanical pulp refiner. The section studies the power consumption in a second stage refiner and calculates the power consumption distribution for the first and second stages. It reveals that the power consumption in a second stage refiner increases along the radius, while in a first stage refiner, the distribution is more even. It states that the innermost part of the second stage refiner seemed to work with a very low energy consumption, compared with the outer parts.

The article quantifies the fiber content of softwood, hardwood and nonwood in packaging grade papers. The author used the standard quantitative fiber analysis techniques to determine the percentage weight factors of the woods. They found out that Kraft liners had 49 percent to 69 percent softwood content than hardwood, and according to the results the most plentiful softwood classes were pines. For nonwood fibers, when entering the papers through the recycling process the fiber component of the papers were only from 2 percent to 9 percent most especially the waster-base papers.

Four hybrid poplars were compared to aspen and balsam poplar to determine their suitability for use in kraft and bleached refiner mechanical pulps (BRMPs). The four hybrid poplar kraft pulps had tensile properties superior to those of pulps from balsam poplar and aspen, the poplars traditionally used in papermaking. High densities for sheets prepared from the hybrid poplars indicated that the cell walls of their fibers were not as thick as those of the two traditional poplars. High strain and tensile energy absorption were found in the sheets derived from the hybrids. Three of the four hybrid poplar BRMPs had bleached brightnesses and light scattering coefficients equivalent to those of aspen. All four hybrid pulps had strength values almost equal to that of aspen pulp, even though their percentages of long fibers were much lower. The hybrid poplar chips were more rigid than those from aspen or balsam poplar, partly because of their higher lignin content. Application: Equal in strength and bleachability to pulps derived from aspen, pulps from hybrid poplars have great potential in papermaking as traditional supplies of hardwood fiber diminish. [ABSTRACT FROM AUTHOR]

A range of ink and paper combinations find their way into the feed furnish of a newspaper deinking plant, in addition to ONP (old newspaper).They include 0MG (old magazines) and a wide range of advertisement inserts and office paper. A change in furnish composition can create problems attaining pulp quality targets. This is apparent during certain periods of the year, such as the peak advertising periods of the "back-to-school" and Christmas seasons. One reason for this problem is an increase in the portion of furnish having a high in k-fiber attachment strength. The ability to measure the ink-fiber attachment force allows these differences to be quantified. In this study, we used a Couette device to measure ink removal as a function of applied force for various ink-paper combinations found in a typical ONP feed furnish. The quantity of ink removed was measured using image analysis. This study showed that the ink-fiber attachment force for aged magazines, advertisement inserts, and xerography printed paper is significantly higher than that of newsprint grades. Due to the magnitude of force required to detach these highly bonded inks from the fiber surface, a significant quantity likely remains attached to fiber following repulping. Reducing the ink-fiber attachment force can reduce the quantity of recalcitrant ink. This can be achieved by increasing the process temperature or adding appropriate chemicals to the pulper. Extending the repulping time may also increase removal of the highly bonded ink, but can also lead to redeposition. This ink can also be detached by application of higher shear forces during dispersion, for example. Application: The findings of this study may help recycling mills increase their deinking efficiency. [ABSTRACT FROM AUTHOR]

In this work, a number of handsheets made from unbeaten and unbleached kraft, refiner mechanical and cotton linter pulps and crack propagations on paper samples under monotonic loading, were analyzed and possible links with the properties of fibrous networks were investigated. Crack initiation and propagation on the tested paper strips were also investigated under a scanning electron microscope to determine visually the state of the paper matrix under applied loads. Furthermore, paper samples were subjected to a series of mechanical tests, such as tearing resistance, folding endurance and tensile strength. The primary goal of this study concentrated on determining the fatigue life responses of paper samples under cyclic loading. An empirical equation for the fatigue life responses of paper samples tested was developed. It was found that paper, being a heterogeneous composite material, responds differently to applied loads depending on the properties of its constituent individual fibers and the nature of interfiber bonding in its structure. Kraft handsheets, for instance, showed the highest mechanical properties, followed by samples made from refiner mechanical pulps and cotton linters respectively. Overall, the equation developed proved to be a good way of predicting the fatigue life of paper materials subjected to variable loads. [ABSTRACT FROM AUTHOR]

Presents an abstract of a peer reviewed research paper which showed that an accurate, cost-effective way to calculate the fiber cross-sectional dimensions can predict several of the properties of paper made from softwood kraft pulp. Use of fiber coarseness to distinguish between large-diameter fibers and small-diameter fibers; Wood density and fiber coarseness; Light-scattering coefficient.