PHOTOELECTRIC METHODS FOR AUTOMATIC LINEAR DENSITY CONTROL COTTON TAPES

The current problem of automatic control and stabilization of the weight of cotton belts at the spinning mill is highlighted. Structural diagrams are given and the principle of operation of an optoelectronic device for automatic control and stabilization of the weight of cotton bands is described. The principle of the optoelectronic method for monitoring the linear density of cotton tapes is stated.

Determination of Optimum Twist Equation for the Long Staple Combed Cotton Ring-Spun Yarn

The aim of this research was to determine the optimum twist equation for ring-spun yarns. The yarn twist can be calculated by different equations. With the research, we tried to find the appropriate equation to determine the yarn twist, which is determined by the values of yarn strength and hairiness. In the research, yarns from long staple combed cotton rovings and of different fineness (10 tex, 11.8 tex, 20 tex and 29.4 tex) were analyzed. The yarn twist was calculated using the equations of Koechlin and Laetsch. The analyzed yarns were produced in the spinning mill on the laboratory ring spinning machine Spinntester. In the second part of the investigation, yarn strength and hairiness were analyzed as a function of yarn twist. The results showed that Laetsch’s equation is suitable for determining the twist for yarns with a fineness of 10 tex, 11.8 tex, 20 tex and 29.4 tex, since, in this case, the calculated number of yarn threads is higher and thus the strength and elongation at break are also higher. The yarn hairiness is higher in analyzed samples for yarns with the twist calculated according to the Koechlin’s equation.

Image Analysis as a Method of the Assessment of Yarn for Making Flat Textile Fabrics

During the technological processing of staple fibers into yarn drafting, waves are formed which increase the irregularity of yarn linear density and consequently affect the yarn quality. Even a correctly performed technological process does not allow one to completely eliminate yarn faults (thin and thick places, neps) and yarn irregularity. All the yarn imperfections distinctly become apparent in flat textiles made of such a yarn. The quality of the yarn produced should be assessed already in spinning mill, using the results obtained to conclude on the quality of woven or knitted fabrics. Modern metrological laboratories in spinning mills possess Uster Tester 5 (UT5) apparatuses that not only assess the yarn quality with respect to the irregularity of linear density, faults (thin and thick places, neps), or hairiness, but also using the test results obtained make it possible to create a digital image of the predicted appearance of a flat fabric made of the yarn tested. This article presents a computer-aided method of the analysis of the woven and knitted fabric images obtained from UT5 that allows one to assess the significance of particular yarn parameters in the predicted appearance of flat fabrics.

Design and Optimization of Process in Spinning Mill to Improve Quality and Productivity of Yarn

Food, shelter and clothing are very basic needs of human beings. Cloths are used by the human beings to protect themselves from light, wind and rain and other environmental factors. Cloths are manufactured from the cotton. In spinning mill industry raw cotton is processed to produce yarn. At present condition quality and productivity of yarn is very important factor and lot of mills failing to achieve the quality as per standards due to this the spinning mills are in financial crisis. In India many spinning mills have stopped their production. So it has direct impact on economical condition of farmers, mill workers and the people who are connected directly or indirectly to spinning mill industry. As it’s affecting the life of many people it is very important to do research work in this field but still now this topic is not touched by researchers in large context. This is the reason why this research work initiated. Various continuous improvements processes are used in industries. Instead of applying single method at one time if we use two methods in integrated approach which compliments each other that will give benefits of both methods in single attempt. To achieve the fine quality of yarn the continuous improvement processes can be used like Six Sigma and Theory of Constraints. If we combine six sigma and theory of constraints and apply over a system as an integrated method that would give us benefits of both methodologies in single attempt with saving of time, money and man power and in results we can achieve fine quality of yarn with increased plant productivity and efficiency which will leads to profitability of mill. In this research by applying the integrated model bottleneck processes were found out and optimum solution is provided by doing improvements in processes. The process capability analysis was done before and after improvements done so we can measure the performance of system. Yarn properties such as unevenness, imperfection index, count variation, hairiness, strength, short fiber content are considered as parameters to measure effectiveness of system. In current system before improvements done there was lot of variation in values of this parameters and by reducing this variations integrated approach leads towards the profitability of spinning mill.

Development of a Method to Compute the Overall Key Performance Index for a Spinning Mill to Aid Supply Chain Management

This paper aims to provide a convenient measure of evaluating the performance of spinning mills using the overall Key Performance Index. Although many authors have advocated the concept of the key performance index, their studies were confined to departments other than spinning. The methodology followed in this paper is based on providing weightages to machine utilisation, spindle production, end breaks, HOK (number of operative hours required to produce 100 kg of yarn), roving production, yarn realisation, CSP (count strength product), units/kg of Yarn and to compute the overall Key Performance Index in a logical manner. It has come to light that some mills have achieved an overall Key Performance Index (OKPI) of more than 100 and less than 100 in certain other mills. Also the important factors which are significant for supply chain management have been highlighted. A very useful source of information and advice for various spinning mills to develop their own supply chain strategies is provided. Especially with the introduction of technical textiles, supply chain management has become a critical area.

Analysis of the Strength Parameters of Worsted and Component Spun Yarns after the Rewinding Process

The notion of yarn is understood as a continuous textile product of theoretically endless length and circle-like cross-section, made of staple or continuous fibres. A yarn leaves the spinning mill in a raw state and is used to produce some fabrics, but mostly it is subjected to the process of finishing. The yarn undergoes preparatory processes, such as winding, doubling, twisting, paraffin treatment, singeing and dyeing, depending of the final fabric type. Yarns are rewound on winding frames, and computers control operation of the rewinding frames and systematically monitor the yarn parameters. An electronic cleaner removes yarn defects, whose size has been saved in the computer memory. The purification of yarn improves its quality, resulting in a decrease in the number of breaks in further technological processes. A lower number of yarn breaks contribute to an increase in machine efficiency (weaving and knitting machines). The experimental section of the study is divided into two parts. The first includes tests of yarn strength parameters before and after the rewinding process. It was established in the process of cleaning that the yarn during rewinding affects the strength of wool and blended yarns. In the second part, the strength parameters of yarn doubling points after the rewinding process for various variants of the splicer setting were tested. The blowing time in the doubling chamber was changed and the importance of using the thermosplicer for the yarn joint strength was established.