94 research outputs found
Winding Core Spun Elastic Yarn on Cone Bobbin to be Dyed
No full textAbstract Spiral yarn composed with an elastomeric filament DOW XLA, from Dow Chemical, and wool fibres outwardly wound around the elastic core presents a complex behaviour when wound on bobbins to be dyed. This article presents a basic mathematical model with the aim of evaluating radial pressure and transversal stress on bobbins at different angles of winding, different yarn tensions and yarn cross-section areas. Considering the additional complexities of the real problem, an experimental comparison of bobbin alterations under different conditions was carried out with the realisation of two experimental sets. The first experimental test bench allows the variation of winding tension, angle of winding and stroke, then experimental tests were carried out on a winding machine SAVIO varying the yarn tension value and adding a mechanical constrain to the device with the aim of reducing yarn-sliding phenomena, in particular during the thermal cycle. The fundamental parameters have been determined as the angle of wind and the yarn tension during the winding operation. Higher values of wind angle help keeping the bobbin shape. Higher values of yarn tension during winding operation allow the preservation of bobbin shape after the dyeing cycle. On the other hand, the upper limit is represented by yarn tensile strength. Moreover, it is not useful to apply a varying wind tension during the winding proces
New method for raising high-quality fabrics
No full textThis article describes the development of an innovative method for raising the surface of high-quality fabrics. The method consists of replacing the natural teasels, currently used, with experimental metal teeth, which do not damage the fabric and reproduce the same effect as natural cards. Literature on the subject contains several examples of artificial metal teeth, which have the advantage of a longer life than the natural ones, however, some can mark the fabric along the warp, if not properly sized. The study in question was based on both experiment and theory, by simulating a flexural load on the barb wire and evaluating its rigidity. Excellent results have been obtained from various tests, and have led to the construction of a new industrial fabric-raising machin
Resistenze batteriche in una rianimazione mista aperta da un anno in un nuovo policlinico universitario
No full text
Surface degradation of linen textiles induced by laser treatment: comparison with electron beam and heat source
No full textHigh-performance device for air interlacing of a yarn and corresponding method
No full textAbstract
A device for air interlacing of a yarn , comprising an interlacing chamber , a first entrance channel for receiving the yarn at the device entrance and feeding it to the interlacing chamber , and a second exit channel for receiving the yarn from the interlacing chamber and releasing it at the device exit, in which the interlacing chamber is delimited by a first emitting wall bearing a nozzle for the emission of a continuous jet of compressed air , and a second deflecting wall , opposite the first wall , suitable for receiving and deflecting the jet of compressed air emitted by the nozzle and intersecting the yarn to be interlaced, and in which the second deflecting wall is concave in shape both on a transversal plane and on a longitudinal plane with respect to the feeding path of the yarn through the device
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