International Journal of Engineering & Technology IJET-IJENS Vol: 11 No: 01 125 117801-6464 IJET-IJENS © February 2011 IJENS I J E N S Customization of Starfish Technology in the Production of Cotton-Knit Fabrics: A Practical Approach A.K.M. Mobarok Hossain 1 , Dr.A.B.M. Zohrul Kabir 2 1 Assistant Professor, Department of Textile Technology, Ahsanullah University of Science and Technology, Dhaka, Bangladesh 2 Professor,Islamic University of Technology,Gazipur,Bangladesh Abstract -- Demands for Cotton-knitted garments have been increasing steadily since 70s as consumers worldwide recognized their comfort and adaptability for all types of regular, leisure and sportswear. While processing order for the buyer, knit-garment makers generally specify their requirements in terms of grams per square meter (GSM), fabric width and shrinkage (both length and width),based on mostly buyer’s requireme nts and processing capability; for a finished knitted fabric of a particular shade. The fabric suppliers (particularly the knitters), on their part, have to choose knitting variables like machine gauge (defined by no. of loop-forming needles per unit circumference of the machine), yarn count (a measure of yarn fineness) & stitch length (length of yarn in a loop).The choice of these knitting variables is important in order to meet the quality specification of the buyers. Sometimes the combination of the requirements as demanded on the finished knitted fabric, is quite impossible to achieve. For this reason it is very common for knitted-fabric manufacturers to carry out a fairly large numbers of sample trials when they are required to develop a new product. These trials can consume considerable amount of time and raw materials, and cause considerable disruption to production schedules, before a satisfactory solution is found. Research works have been carried out worldwide for developing a practical system for reliably predicting the shrinkage and dimensional properties of finished Cotton–knitted fabrics. The most recognized effort may be that of IIC (Recent CTI) termed as STARFISH. It is a computer program, and a body of know-how which can demonstrate how to engineer cotton circular knits so that the quality and the performance can be right first and on time. To use STARFISH with the simplest option , the user has to give input variables of machine gauge, yarn count and stitch length mainly as well as specifying a target value of GSM and fabric width or shrinkage. In case of target GSM and fabric width, the STARFISH gives shrinkage as outputs and in case of target shrinkage; the software gives GSM and fabric width as outputs. But as STARFISH outputs represent the results developed from many industrial trials of different countries, the user just gets the standard average values of GSM, Width and Shrinkage of a particular fabric from S TARFIS H. S o to customize this software in a particular factory, the results given by S TARFIS H has to be calibrated according to the factory results. Though the software provides a self-calibration method which is more experimental, a quick calibration procedure will definitely be more users friendly and support the application of this software more practically in a real factory situation. In this work, first, the relationship between STARFISH inputs (yarn count and stitch length) and outputs (GSM/Width) has been established through a set of multiple linear regression models for each specific machine gauge. The models thus developed have a high degree of correlation ship. Consequently, the regression models can be used as a substitute of STARFISH to predict outputs with a high accuracy under similar environment. Secondly STARFISH predicted results have been compared with recorded results of Beximco Knitting Limited (A renowned knitting factory of Bangladesh) using standard statistical measures in order to customize STARFISH as a real factory case. It was observed that the mean absolute percentage error (MAPE) is less than 5% for all machine gauges. The findings thus clearly establish a quite advantageous approach for applying such technology for the selection of decision variables. Index Term-- Knitting, Gauge, Yarn Count, Stitch Length, GSM, Shrinkage 1. INTRODUCTION Knitting is a process of fabric manufacturing by interlocking series of loops of one or more yarns. Knitted fabrics are used to produce garments that cover every part of the human body, in a wide range of garment types from socks, caps, gloves and underwear to upper and lower body garments varying from T- shirts to formal jackets. The dramatic increase in the popularity of knit fabrics during the last three decades provides a vivid example of the interrelationships between lifestyle, technology and fashion. The high degree of stretch and comfort that knit cloth brings to close-fitting garments, coupled with excellent wrinkle resistance, makes them eminently suitable to the modern consumer s demands. Unlike weaving, knitting cannot commence with any type of yarn. Knitting requires a relatively fine, smooth , strong yarn with good elastic recovery properties. Cotton yarn is proven worldwide as particularly suitable for knit garments like underwear, outerwear, sportswear and socks. Though the development of synthetic fibers brought revolution to the clothing industry, cotton-knitted fabrics have always enjoyed great popularity among all kinds of knitted fabrics. Due to unprecedented competition in the global apparel industry customers are demanding better quality in terms of improved performance (e.g. lower shrinkage and better retention of shape and performance). The International Institute for Cotton