Browsing by Author "Nosek, Stanislav"
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- ItemDynamics and stability of beat-up at high weaving rates(1995) Nosek, StanislavIn this paper the equilibrium between the determining quantity for a given weft density, the impulses of beat-up force and the delivered action impulses provided by the loom mechanisms is discussed from various points of view. Theoretically for each weft density the loom will always reach a standard state due to its inner autocontrol abilities. Nevertheless weaving resistance, being a property of the given system warp-fabric, increases with the beat-up frequency independently from the used loom and the weaveability of higher weft densities becomes more difficult. The main laws which rule these effects are discussed.
- ItemPeculiar behaviour of the loom's back-rest roller(1997) Nosek, StanislavThis paper presents an analysis of the dynamic model of the back-rest roller motion. On modern high-speed looms with growing weaving resistance, the normal beat-up pulse delivered by the conventional reed is not able to produce the desired fabric style. It is necessary to deliver an additional beat-up pulse. In order to determine if the motion of the back-rest roller generates a secondary beat-up, the behaviour of the back-rest roller during weaving is analyzed influencedby loads which are the result of warp tension, weft beat-up and opening the shed. The backward and forward rotation of the back-rest roller are pointed out and the conditions for backing (backward rotating) are determined. It is also shown that the permanent sliding practically eliminates the influence of abrasion of warp by the roller on warp tension. Thus it is impossible to transfer the inertia forces of the back-rest into the secondary beat-up.
- ItemA study on the occurrence of stop marks and periodic bars in fabric(1996) Nosek, StanislavThis study has been carried out in response to the request of Zbrojovka A.S. Vsetin, a producer of weaving looms. The firm, being aware of the difficulties connected with developing new looms with higher performance while maintaining their weaveability on the necessary level, decided, in collaboration with the Department of Weaving Technology of the Technical University in Liberec, to start a research programme studying the effect of dynamics of the high speed weaving process on the quality of produced fabric and on the stability of fabric formation. This paper deals with a particular problem of this programme - with the possibilities and causes of the occurrence of weft bariness in fabric on weaving machines at high weaving speeds.