Band 9, Heft 1

This work presents the contribution of optimisation analysis of the performance of wet pneumatic spliced cotton yarns using two different methods: the superimposed contours method and the function of desirability. Cotton yarn linear density (Yc), length of splice (SL), duration of water joining (Dwj) and duration of air joining (Daj) were optimised in the experimental field of interest. In this study regression equations expressing multi-component splice mechanical performances were elaborated by using the response surface method. In order to validate the results, a desirability function, multi-objective technique was used to select optimal parameter zones which give high splice behaviour. The results show that there are zones of compromise where wet pneumatic splice behaves better before weaving. In this work, the spliced yarn performance was optimised.

In the present study, an attempt has been made to impart antimicrobial finishing on cotton woven fabric using nano silver solution, at various concentrations: 5 gpl, 10 gpl, 15 gpl, 20 gpl, and 25 gpl in the presence of PVOH (5 gpl, 7.5 gpl and 10 gpl) and an eco-friendly cross linking agent, namely 100gpl glyoxal/65 gpl Appretan N 92111 (binder) applied by the pad-dry-cure technique. Curing conditions were varied, keeping curing temperatures at 140 oC, 150 oC, and 160 oC and curing times to 1 min., 2 mins., and 3 mins. To assess the quality of the finished fabric, various properties like tensile strength, bending length, crease recovery angle, and zone of inhibition were studied. The zones of inhibition have been studied using Staphylococcus aureus and Escherichia coli bacteria to determine antimicrobial activity. To observe the polymer formation in the finished fabric, the surface characteristics of these fabrics have been studied using Scanning Electron Microscopy (SEM). In the case of commercial Product A (Sanitized® T 27-22 Silver) treated cotton fabric, the zones of inhibition are a minimum of 24 mm and maximum of 29 mm for Gram-positive bacteria and a minimum of 14 mm and a maximum of 18 mm for Gram-negative bacteria. In the case of commercial Product-B (Sanitized® T 25-25 Silver) treated cotton fabric, the zones of inhibition are a minimum of 24 mm and a maximum of 29.5 mm for Gram-positive bacteria and a minimum 14 mm and a maximum of 18.6 mm for Gram-negative bacteria. SEM study of antimicrobial finished fabric reveals that a continuous polymer film has been formed on the fabric. The concentration of PVOH controls the bending length and crease recovery angle. The higher the concentration of PVOH, the higher will be the bending length and crease recovery angle. Curing temperature and time have a profound impact on tensile strength. The higher the curing temperature and time, the lower the tensile strength.

The manufacture of core yarn from polyester-cotton is one of the most important developments in the textile industry. The use of core yarns is mainly aimed at improving the strength, comfort, durability, aesthetics, and other functional properties of the final yarn. This article reports the results of investigation of core spun yarns made from polyester filament as core and cotton as sheath material manufactured using both ring and air-jet spinning systems. Polyester filaments with different proportions were chosen for the core component and cotton was used as the sheath. A total of twelve different core yarns were made on different spinning systems (i.e. six on air-jet and six on ring frame systems) and the yarn properties were compared with those of 100% cotton ringspun yarn. It was observed that core yarns had improved physical properties compared to 100% cotton ringspun yarn in many respects such as yarn strength, elongation, energy to break, and yarn imperfections. Only airjet core yarn showed lower yarn strength than 100% cotton yarn but the same yarn excelled in other properties compared to 100% cotton yarn.

The shock behaviour of crop straw reinforced composites with unsaturated polyester epoxy was studied. In this research an attempt has been made to design and manufacture protective composite vests for soldiers. The low velocity impact loading was generated by a drop weight impact machine with drop heights varying from 100 to 200 mm. The drop mass used in these experiments was 15 kg. The shock-absorbing capacity of the vests was found to be strongly affected by straw type, straw weight percentage per unit volume of composite panel (the permanent composite volume of the panel is equal to 434.2 cm3), and broken short rounded straight steel wire to straw weight ratio. This research concerns the evaluation of all the low velocity drop weight test parameters such as peak dynamic force, duration time, and impulse due to free falling of drop mass at different impact energies: 1.5, 2.25, and 3 J. In addition, indentation parameters such as contact force and absorbed energy could be evaluated. Mathematical models describing these parameters are presented in a form that can be easily predicted. The predicted shock-absorbing capacity shows good agreement with the experimental results. In addition, the optimum tailoring variables affecting the shock-absorbing performance of the composite vest system could be determined.

Cotton fabrics were dyed with natural colouring matter extracted from Crocus sativus (saffron) using a traditional heating method and a power ultrasonic method. Factors affecting the dyeing properties such as pH values, salt concentration, temperature, duration of dyeing bath, and ultrasonic power were studied. Environmentally friendly mordants were used in pre-mordanting, post-mordanting, and simultaneous-mordanting methods. The fastness properties including light, washing, and perspiration of dyed and mordanted fabrics were assessed. Colour strength (K/S) was measured for dyed and dyed mordanted cotton fabrics.

The aim of the experiment was to bring closer the possibilities of using corona discharge photography (CDP), with special emphasis on the impact of textiles on corona discharge photography of human fingertips in contact with those textiles. The article describes an investigation concerning a short period of contact with textiles and their influence on human parameters such as blood pressure (BP) and heart beat (HB) as well as images of corona discharges (ICD). The authors were searching for a new method of demonstrating the influence of textiles on human subjects. As the research involved contact of textiles with human skin, certain static and friction issues were raised. Textile materials were chosen for the experiments on the basis of their tribological features. The ICDs used here were created as a result of placing body parts, e.g. fingers, in the area of a strong electrical field of high voltage (10 KV) and high frequency (1024 Hz). A digital camera placed within the area of discharge recorded this phenomenon. The temperature, air humidity, and air pressure in the examination room as well as gender, age, HR, BP and in the case of female volunteers, their menstrual cycles, exerted an effect on ICD in the study group. ICD of human beings seems to be a kind of marker of tribological features of textile materials.