Doubling of sliver has ceased to be the fundamental operation for reducing the weight irregularity of spinning halfproducts, which are decisive for the quality of yarn. Its role has now been taken over by the general use of autolevellers. After leaving the regulation zone, card sliver, whose weight irregularity is reduced by a short-termautoleveller, undergoes a process of relaxation. This phenomenon takes place only in the case of regulated sliver. Unregulated slivers passing through a leveller operating with constant draft show few relaxing properties. One reason why autolevelled card sliver has such relaxing properties may be the variation of the drafting force caused by the continually changing draft. The performance of the short-term card autoleveller cannot be unequivocally evaluated. The main difficulty lies in the time span between levelling and measurement, during which the sliver undergoes relaxation. How quickly the autolevelled card sliver is fed to the next machine in the yarn manufacturing process is therefore important, because in the intervening time the initial irregularity of the product may undergo uncontrolled changes.
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This paper presents the results of an observation and investigation into the wear of the rotors of an open end spinning machine mating with wool yarn in industrial conditions. The rotors were made of alloys EN AW-2024 (AlCu4Mg1) and EN AW-6082 (AlSi1MgMn) after a process of hard anodic oxidation in industrial conditions. Analysis of the wear process together with the decrease in the oxide layer thickness before and after the operation certifies that such a layer assures at least a two and a half fold increase in wear resistance. The surface topography and microstructure of the surface layer before and after the period of operation were assessed, which allowed us to establish that the wear of the inner surfaces of the rotor in the collecting groove caused by the friction of impurities and yarn on their surfaces is mainly determined by the abrasive wear.
PL
W pracy zamieszczono wyniki obserwacji i pomiarów zużycia, w warunkach przemysłowych, rotorów przędzarek bezwrzecionowych do wełny i włókien wełnopodobnych wykonanych ze stopu EN AW-2024 (AlCu4Mg1) oraz ze stopu EN AW-6082 (AlSi1MgMn) przed i po procesie utleniania elektrolitycznego twardego. Analiza przebiegu zużywania się oraz grubości warstwy tlenkowej, przed i po okresie eksploatacji, potwierdza, że warstwa tlenkowa zapewnia co najmniej dwuipółkrotny wzrost odporności na zużycie. Ocena topografii i mikrofotografii powierzchni oraz mikrostruktury warstwy wierzchniej, przed i po okresie eksploatacji, pozwala na stwierdzenie, że na zużywanie się powierzchni wewnętrznych rotora w rowku zbiorczym, podczas tarcia zanieczyszczeń i przędzy o te powierzchnie, decydujące znaczenie ma zużycie ścierne.
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Reliability prediction of spinning machines can result in a time-saving and cost-saving development process with high reliability. Based on an analysis of failure times among systems and subsystems, a simulation method for reliability prediction of spinning machines is proposed by using the Monte Carlo simulation model. Firstly, factor weights are determined according to the fuzzy scoring and analytic hierarchy process. According to the status of reliability growth, growth coefficients are proposed based on reliability influencing factor weights and fuzzy scoring. To achieve the prediction of reliability distribution law, reliability index, and fault frequency, the reliability prediction model is constituted by combining the reliability growth coefficient and the Monte Carlo simulation model. Simulation results for spinning machines are obtained via the model thus built, which are confirmed with a practical example.
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Friction (DREF II) spinning system is one of the promising spinning methods to produce yarns for technical textile applications. The core positioned exactly center and the spinning tension will be very less compare to ring and rotor spinning systems. In an experimental study to produce 6's Ne core spun yarns in DREF II spinning machine, the polyester /viscose (70/30%) sliver was used as sheath component and drawn polyester filaments (150 denier/36) were used as core component. Yarns were produced with the different core/sheath components (0/100%, 16/84%, 30/70%, 50/50% and 70/30% respectively).Friction ratio was kept at 3.33 and the feed rate was changed to produce above 6's Ne core spun yarns. Core spun yarns found that more even and high modulus than the parent friction spun yarn. The filament-core in the yarn appeared to have twisted configuration. The direction and level of twist was difficult to ascertain in these yarns. High core component yarns were found less hairy. S3 values of the yarn found minimum with increment in the core proportion in the yarn. Sheath strength contribution was analyzed with respect to the core filaments and found that the less core proportion yarns have high contribution to the tenacity.
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Coir fibre is a non-conventional fibre extracted from the husk of coconut fruit and is abundantly available in tropical countries. Coir yarn is produced in the decentralised cottage industry. Increase in the demand for the coir fibre yarns for value-added applications has forced the coir yarn manufacturers to improve the existing coir spinning machine in different ways. In this study, the working principle of the existing coir spinning machine has been studied from the perspective of further improvements in production rate, yarn quality and spinning performance. Modifications have been made in the existing coir spinning machine in fibre feeding, opening and cleaning. There is improvement in the production rate of up to 20% with significant improvements in the yarn quality and spinning performance.
W artykule opisano rozwój technologii kształtowania obrotowego blach w Instytucie Obróbki Plastycznej na przestrzeni ponad 40 lat. Scharakteryzowano najczęściej stosowane metody wyoblania i zgniatania obrotowego. Opisano urządzenia i maszyny zaprojektowane i wykonane w Instytucie oraz niektóre technologie nad którymi prowadzono badania. W dalszej części opisano badania rozwojowe głównie na potrzeby przemysłu krajowego. Wyniki tych badań wykorzystano przy wdrożeniu nowych technologii i specjalistycznych maszyn. W końcowej części przedstawiono przyszłościowe kierunki rozwoju technologii kształtowania obrotowego.
EN
The paper presents the development of sheet metal flow forming technology in the Metal Forming Institute during the period of over 40 years. The most often used methods of spinning and flow forming have been described. Devices and machines designed and executed in the Metal Forming Institute have also been described, as well as some technologies which had been investigated. Further part of the article describes development research, mainly for the needs of domestic industry. The results of the investigation have been used when implementing new technologies and specific machines. In the final part, future directions of the development of flow forming have been presented.
W artykule opisano przebieg i wyniki badań technologii kształtowania obrotowego tarcz przepustnic centrycznych. Badania obejmowały kształtowanie tarcz dolnych i górnych dla przepustnic DN-600 i DN-500. W pierwszym etapie badania prowadzono na tarczach ze stali tłocznej, a następnie ze stali nierdzewnej OH18N9 (14301) i OOH17N14M2 (14404). Pierwszą operację wyoblania realizowano na wzorniku jednolitym, a drugą operację wyoblania obciskającego na wzorniku składanym. Między tymi operacjami stosowano obróbkę cieplną (przesycanie) dla stali nierdzewnej. Przepustnice centryczne DN-600 i DN-500 z obudową składającą się z dwóch wykonanych tarcz otrzymały Złoty Medal EURO DYSC na Międzynarodowych Targach POL-EKO 2007.
EN
The article describes the procedures and results of investigation of the technology of flow forming disks of centric chokes. The investigation comprised forming of the lower and upper disks for the DN-600 and DN-500 chokes. In the first stage, the tests were performed on disks made of stamping steel and then on one of stainless OH18N9 (14301) and OOH17N14M2 (14404) steels. The first spinning operation was performed on a solid templet and the second operation of necking spinning on a built-up templet. Between the two operations, heat treatment (hyperquenching) was applied for stainless steel. The centric chokes DN-600 and DN-500 with casing consisting of two disks made by us have been awarded a EURO DYSC gold Metal in the international POL-EKO 2007 Fair.
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