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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]

Reconstituted parchment is, besides Japanese paper and parchment, a feasible and widely used material for filling in losses in parchment. This study investigates changes in haptic and visual qualities of the material caused by modifications with different ingredients like paper and parchment fibres. Additionally, selected procedures processing parchment to parchment powder were examined. As a brief introduction, the paper gives an overview over the existing types of reconstituted parchment that are used traditionally in parchment conservation. In addition it attempts to clarify the terminology for this material. Parchment powder was produced with simple and readily available equipment, by different methods: sanding, grating, grinding, shredding, milling and ice-crushing. The different types of home-made powder were compared to a pre-fabricated parchment powder obtained from a parchment maker. The test series showed that the type of preparation of parchment powder influences the fibre texture which in turn affects the material's properties visually and haptically. While all methods are clearly more time-consuming than buying ready-touse material, some preparations, e.g. grating, shredding and ice-crushing, showed superior properties. [ABSTRACT FROM AUTHOR]

Mixtures of stickies-containing and stickies-free pulps were investigated for their deposition potential in an attempt to better understand the interactions of dissolved and colloidal material (DCM) when mixing two different pulps. The filtered pulp mixtures were tested in a deposition apparatus which measures both the dynamic fluid as well as impact deposition by an established optical scanning method. A pulp filtrate of model stickies led to deposition according to the proportion of stickies-containing pulp in the mixture. Other mixtures of pulps, however, led to deposition that differed from the predicted value. It is theorised that pulp fibres present in the mixture could adsorb the polysaccharides that would otherwise keep the colloidal system electrostatically stable. This destabilisation was most prominent at lower proportions of the stickies-free pulp suspensions used for mixing. These results show that care must be taken when mixing different pulps for paper and board production, as even a small amount of replacement pulp can lead to destabilisation of DCM and formation of deposits. Furthermore, special care must be taken when mixtures of pulps are used to validate stickies measurements. [ABSTRACT FROM AUTHOR]

The activation parameter developed is based on the fiber wall thickness distribution, fiber curl distribution, and water retention value of the unrefined fibers. The mechanical properties of paper that contain chemical pulp depend, among other things, on the free fiber segment activation between fiber-fiber crossings that is created during drying. Experimental data revealed that the degree of fiber swelling is responsible together with the fiber shape factor (curl) and fiber wall thickness for the extent of fiber network activation. The amount of bonding between fibers also affects fiber segment activation. Based on the experimental data, it was deduced that interfiber bonding ability of fibers, characterized as the water retention value, was mainly responsible for the development of handsheet density. Tensile index development was more affected by the morphology of fibers, which was the main determinant for high activation potential of fibers. Factor analysis was used to identify the main causes of variation for a refining data set of 20 Eucalyptus grandis samples. Three independent descriptors were found to be responsible for the majority of the variation: the bonding and activation factor, the factor of microcompressions, and the factor of fiber wall thickness and fiber curl. The activation parameter developed in this study can be used to determine the effect of fiber segment activation and inter-fiber bonding on the inplane mechanical properties of paper. [ABSTRACT FROM AUTHOR]

AbstractThe aim of the present study was to determine the effect of a variety of abnormal fibres on the mechanical properties of paper made from Norway spruce, Picea abies(L.) Karst. Fibres representing abnormality were obtained from trees treated by irrigation and fertilisation. Moreover, fibres from compression wood and its accompanying opposite wood were isolated. The effect of dislocations on paper quality was studied on four mixtures (20, 40, 60 and 80% fibres with induced dislocations) of untreated/compressed fibres. Two more groups consisting of control untreated samples and samples with 100%-induced dislocations were also included in the test. The mechanical properties of the paper were tested and the results were compared to those of control samples. Abnormal fibres reduced the desired mechanical properties of the final paper concerning tensile strength, modulus of elasticity and tear-tensile index. Irrespective of the type of treatment, all morphological changes introduced in fibre cell walls appear to directly affect changes in the mechanical properties of the paper. Control samples had a tear index of 25 compared to 10 mN m2g-1of samples containing 100% dislocations. It is obvious that 20% of dislocations, an amount that is expected to be induced in pulp under mechanical processing and transport, will contribute to a decrease in tear index with an average of 3 mN m2g-1, i.e., 10% of the total value. [ABSTRACT FROM AUTHOR]

This article presents the author's views on the optimization of leafcasting technique. Leafcasting is used for the production of various conservation paper samples of different fibre types and additives, as well as optimising the technique for conservation. Many research concentrated on the influence bleached and unbleached cellulose fibre had on the quality and on the permanence and stability of the resulting paper. Leafcasting technique is advantageous in comparison to manual methods. Leafcasting is faster and provides superior aesthetic quality and homogeneity between the old paper and the new fill.

Two terms, permanence and durability are often used to express the ageing behavior of paper. Permanence relates to the retention of a paper's mechanical properties over prolonged periods, while durability expresses the degree to which a paper retains its original qualifies under continuous usage. Usually, strength and optical properties are important in most papers in which permanence is to be studied. Paper strength depends upon fiber strength and the strength of intermediate bonds, the latter being the more critical, but the significance of fiber strength in the resulting paper strength cannot be neglected.