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In textile production, the yarn is being withdrawn from cross-wound packages in warping and weft insertion. During unwinding, there appear forces in the yarn which are approximately proportional to the square of the unwinding velocity. The production process requires as large warping and weaving speeds as possible, therefore it is necessary to improve our understanding of the cross-wound package unwinding and to find the necessary modifications of the yarn unwinding process. In addition to empirical tests, it has proved useful to study yarn unwinding by mathematical modelling and computer simulations. We state the eguations of motion that describe the unwinding yarn and develop a mathematical model which permits to simulate the process of unwinding. [ABSTRACT FROM AUTHOR]

The study compares conventional and recycled office paper, based on experimental work. To confront the market needs, we have to find alternatives in respond to enormous necessity and application of office paper. Therefore, one way in dealing with the problem is to replace or just decrease the use of paper made entirely from primary components, mainly wood fibres (deciduous and conifer). We analysed mechanical, optical, structural and microscopic properties of conventional and recycled office papers. Experiments were performed on three conventional and three recycled office papers attainable on the market. The results obtained from measurements confirm the presumption that the mechanical and surface properties of recycled office paper can be collated and they discern from conventional office paper. [ABSTRACT FROM AUTHOR]

Eco-design has become very important in last few years. According to the environmental suggestions not to waste materials, energy etc., and use of recycle materials we were study paper recycling process in relation to used printed typefaces, their sizes and used different leading. For prints conventional and model offset inks with greater environmental benefits were used for printing. Characteristics of the recycled fibers followed by image analysis and some spectrophotometric methods are discussed. The results of these studies except for the scientific contribution should serve as a reference in design, especially for environmentally friendly graphic products. [ABSTRACT FROM AUTHOR]