The conventional rotor spinning unit generates flow vortices in the transfer channel upstream region which affect the fiber configuration and consequently yarn properties. Geometry and spinning parameters such as transfer channel length, inlet width, rotor outlet pressure, opening roller speed, and diameter were found to be key parameters influencing airflow characteristics. To reduce the flow vortices in the upper stream region, modifications of the transfer channel were proposed, and their airflow fields were analyzed using computational fluid dynamics. Three designs were studied: a round transfer channel inlet, a bypass channel for extra air supply, and one with both the bypass and the round inlet. Analysis of airflow revealed that the design with both round transfer channel inlet and a bypass proved to be very effective in properly directing the flow and minimizing vortices. The design was also characterized by smoother velocity streamlines and maximum mass flow across the transfer channel. A conventional rotor spinning unit was modified in which a round transfer channel inlet corner and a bypass channel were utilized to conduct the experimental tests. Three sets of yarn samples were produced using the conventional and modified rotor spinning units under different rotor speed conditions. Yarn properties were tested. Properties such as tenacity, CVm%, and thin and thick places of the spun yarns produced by the new design improved compared to that of the conventional yarn.
The increasingly widespread use of non-ionic surfactants as main ingredients in domestic detergent formulations requires an understanding of their performance during washing, not only as separate products but also as binary mixtures with anionic surfactants. In order to attain acceptable levels of biodegradability and toxicity, alkyl polyglucosides (APGs) have appeared on the market. These non-ionic surfactants, obtained from natural substances (saccharides), are 100% biodegradable and have very attractive features for application to washing. They are highly soluble, only slightly sensitive to the presence of electrolytes and rarely affected by water hardness. The aim of our work was to analyze behavior in the staining of undyed cotton fabric with the dye desorbed in the washing of cotton fabric previously dyed and finished with resin and softened, by means of the use of the surfactant APGs with sodium dodecyl benzene sulfonate, separately and in mixtures in different proportions. Likewise, the staining of undyed diacetate, polyamide, polyester, acrylic, cotton and wool fabrics was obtained. The cotton was previously dyed with red, orange and blue direct dyes. The behavior of the discoloration of dyed and finished and unfinished cotton fabric and the staining of undyed fabrics in washing were related to the zeta potentials of the fabrics obtained by the streaming potential method in the presence of the surfactants and their mixtures used After washing, the undyed fabric with the anionic surfactant showed a greater difference in color than non-ionic surfactant and when the concentration of the non-ionic surfactant in the mixture was increased the color difference decreased. The zeta potentials (absolute values) of undyed and dyed and finished cotton fabric in the presence of these surfactants gave the same order values, which increased with the surfactant concentration
Manich, A.M.; Lopes, R.; Dos Santos, M.; Lucas, J.; Martí, M.; Cayuela, D. Textile research journal Vol. 84, num. 18, p. 1961-1975 DOI: 10.1177/0040517514530034 Data de publicació: 2014-11-01 Article en revista
Polyester fibers (PET) are greatly used in textiles but depend on fossil fuel resources. Poly-(lactic acid) (PLA) is an aliphatic polyester that can be derived from 100% renewable resources. The load-extension plot of a polylactide fiber seems to be especially compatible with that of wool. Consequently polyester/wool 55/45 and polylactide/wool 55/45 yarns were spun using the Sirospun process and plain and twill woven fabrics were industrially produced. Washed and heat set fabrics were subjected to a conventional process of dyeing and decatizing. Fabrics were gradually worn by abrasion using a Martindale wear and abrasion tester.; Using the bursting strength test, the viscoelastic behavior of the fabrics when multidirectional extended was simulated and modeled using a modified non-linear Maxwell model. The three steps of fiber decrimping and orientation, fiber stretching and maximum yield and breaking were analyzed. PET/wool fabrics show a more linear behavior than PLA/wool ones and the influence of weave, finishing and wearing on the viscoelastic behavior of PLA/wool fabrics were highly relevant when compared with that on PET/wool ones. It seems that when blended with PET, wool develops its felting effect during finishing and wearing, while when blended with PLA, the felting effect of wool is hardly developed due to the lower resistance of PLA to hydrolysis and its lower thermal stability. PLA fiber properties need to be improved probably through the development of new L-D lactide (PLDLA) copolymers of different ratios between components and molecular weights to reach the optimal desirable properties for the fiber.
Cayuela, D.; Montero, L.; Riva, A.; Prieto, R.; Martí, M.; Manich, A.M. Textile research journal Vol. 83, num. 10, p. 1065-1074 DOI: 10.1177/0040517512474361 Data de publicació: 2013-06 Article en revista
Polylactide fibers (PLA), textured by false twist at different temperatures (135, 150 and 165º C) and draw ratios (1.30, 1.35 and 1.40) were stabilized by the application of a continuous thermal treatment at 100º C and 50 m/min. The effect of thermal stabilization on the microstructure was determined by physicochemical tests such as iodine sorption or differential solubility. Iodine sorption and differential solubility are closely related to the crystallinity of the samples. Stabilization enhances crystallinity and orientation with the result that differences between the samples are diminished. Color value differences, albeit reduced, in some cases exceed the accepted limits. Color absorption is mainly dependent on the orientation and accessibility of the amorphous phase
Cayuela, D.; Montero, L.; Riba, M.; Prieto, R.; Cano, F.; Manich, A.M. Textile research journal Vol. 83, num. 10, p. 1055-1064 DOI: 10.1177/0040517512474360 Data de publicació: 2013-06 Article en revista
Polylactide fibers (PLA), false-twist textured at different temperatures (135, 150 and 165º C) and draw ratios (1.30, 1.35 and 1.40) were stabilized by a continuous setting treatment at 50 m/min and 100º C using a specially designed chamber. The crystallinity and the orientation of the original textured filaments and those of the stabilized ones were measured. The effect of post setting on the dimensional stability, mechanical properties and thermomechanical behavior in accordance with the texturing conditions was studied. The relationships between crystallinity and the dimensional stability and between the orientation and both the relaxation shrinkage and the endset temperature of shrinkage were considered
The characterization of the microstructure of synthetic fibres is necessary to identify changes in properties produced by
differences in the production variables. To this end, two physico-chemical tests (iodine sorption and differential solubility),
which are easy and rapid to implement were employed to study the differences in the microstructure of polylactide
false-twist textured multifilaments. The results enabled us to identify variations in microstructure induced by texturing
conditions and were related to processing variables. These tests were compared with more expensive and complicated
techniques to quantify crystallinity and orientation of filaments. Both tests enabled us to identify microstructure
variations between substrates
The characterization of the microstructure of synthetic fibres is necessary to identify changes in properties produced by differences in the production variables. To this end, two physico-chemical tests (iodine sorption and differential solubility), which are easy and rapid to implement were employed to study the differences in the microstructure of polylactide false-twist textured multifilaments. The results enabled us to identify variations in microstructure induced by texturing conditions and were related to processing variables. These tests were compared with more expensive and complicated techniques to quantify crystallinity and orientation of filaments. Both tests enabled us to identify microstructure variations between substrates
Riera, M.; Gutierrez-Bouzán, C.; Valldeperas, J.; Lis, M.; Crespi, M. Textile research journal Vol. 81, num. 18, p. 1926-1939 DOI: 10.1177/0040517511413316 Data de publicació: 2011-11 Article en revista
In this study, the influence of an electrochemical pre-treatment was evaluated in dyeing wastewater reuse for five reactive dyes for cotton fabrics. The most proper dyeing method was established and the influence of alkali was also studied. Wastewater was treated in an electrochemical cell at 20 Lh_1 and 40 mA/cm2 for between 3 and 15 minutes before being reused. During the electrochemical treatment the evolution of the dye degradation was evaluated by COD measurements. From the results, it can be concluded that 70% of the wastewater can be satisfactorily reused by direct bath reuse with most of the reactive dyes obtaining DE (CMC (2:1)) values below 1 with respect to the reference. Differences of DE (CMC (2:1) can be improved up to 75% by applying an electrochemical pre-treatment. In DE (CMC (2:1)) values, DL* was found to be the most influential parameter. Finally, the influence of the level of dye degradation in the wastewater was observed as non-relevant in the direct reuse of the bath for most of the studied dyes
Manich, A.M.; Lopes, R.; Lucas, J.; Franco, F.; Baena, B.; Carilla, J.; Montero, L.; Cayuela, D. Textile research journal Vol. 81, num. 17, p. 1788-1795 DOI: 10.1177/0040517511411972 Data de publicació: 2011-10 Article en revista
Paul, R.; Bautista, L.; de la Varga, M.; Botet, J.; Casals, E.; Puntes, V.; Marsal, F. Textile research journal Vol. 80, num. 5, p. 454-462 DOI: 10.1177/0040517509342316 Data de publicació: 2010-03 Article en revista
Rubio, L.; Alonso, C.; Coderch, L.; Parra, J.; Martí, M.; Cebrian, J.; Navarro, J.; Lis, M.; Valldeperas, J. Textile research journal Vol. 80 (12), p. 1214-1221 Data de publicació: 2010-01-28 Article en revista
Biofunctional textiles are materials with new properties and added value. In this work, emphasis was placed on the release capacity of the active principle (caffeine) from the formulation or from the biofunctional textile. In addition, a new in vitro methodology of percutaneous absorption was designed to demonstrate the delivery of encapsulated caffeine from the biofunctional textile to the different skin layers. In the first step, permeation studies through a nylon membrane were performed and the release capacity of caffeine present in the samples was quantified. In the second step, it was possible to detect the presence of caffeine in the different layers of the skin, while maintaining a close contact between the biofunctional textile and the skin by using pressure during the percutaneous absorption test. The new system is satisfactory for measuring the pass of the active principle from the biofunctional textile to the different skin layers.
Carrillo, F.; Colom, X.; Valldeperas, J.; Evans, D.; Huson, M.; Church, J. Textile research journal Vol. 73, num. 11, p. 1024-1030 DOI: 10.1177/004051750307301114 Data de publicació: 2003-11 Article en revista