India’s Textile Industry is one of the leading textile industries in the world. Though it was predominantly an unorganized industry even a few years back, the scenario started changing after the liberalization of the Indian economy in 1991. The opening up of the economy gave the much-needed thrust to the Indian textile industry, which has now successfully become one of the largest in the world.The Indian textile industry largely depends upon the textile manufacturing and export. It also plays a major role in the economy of the country.
Today, the Indian textile industry contributes about 14 per cent to industrial production, 4 per cent to the country's gross domestic product (GDP) and 17 per cent to the country’s export earnings, according to the Annual Report 2009-10 of the Ministry of Textiles. The industry provides direct employment to over 35 million people and is the second largest provider of employment after agriculture.
In most sectors of textile manufacturing, automation is one major key to quality improvement and cost competitiveness. Early modernisation and technical developments in textiles concentrated on the automation of individual machines and their processes. Here, all process and machine variables were identified and placed under the surveillance of monitors or microprocessors. The machine and operating parameters of acceptable change were studied and programmed to control the quality and reproducibility of materials being produced.
Throughout the 1990s, Computer Integrated Manufacturing (CIM) and Flexible Manufacturing Systems (FMS) had been the dominant production philosophies of the textile and clothing industries, both in developing and in developed countries. The ultimate goal was however a fully automated textile mill. On the whole, the industry has moved from the era of computer applications in textile operations to the era of computer integrated textile manufacturing.
The main objectives of Computer Integrated Manufacturing (CIM) is, to first to provide accessible information for every sector of a plant for the efficient management of the various stages of production, second, to provide facilities for planning and control at strategic points, available for the directors, managers and supervisors to make decisions and third, to have compatible sophisticated high technology systems - particularly software - so that computers can talk to one another within the network, and modules can be linked with other modules, accepting additional work stations as the business grows.Some examples where automation becomes important in textile manufacturing are mentioned below.
The history of the man-made fibre industry has emphasised process control more than any other segment of the textile operation. Increasing emphasis on product uniformity and adherence to quality standards continues to require fibre diameter monitoring, temperature and tension control, and monitoring of the solution properties of the polymer. These requirements are especially critical in micro-denier fibre extrusion, a process that produces fibres and eventually fabrics of truly different properties.
Computer Integrated Manufacturing Systems are available that monitor and/or control practically all yarn production processes from opening and blending to spinning, winding and twisting. Online quality control in carding and drawing can perform spectral analysis and determine the cause of problems based on the frequency analysis of the defects. Weaving and knitting machine builders have been leading the way in utilising computer technology in textile manufacturing for many years with their use of CAD, bi-directional communication and artificial intelligence. With the availability of electronic dobby and jacquard heads, automatic pick finding, and needle selection, etc these machines are the most easily integrated into computer networks of any production machines. Bi-directional communication systems can be used to control many functions on a weaving machine. CAD system can be used to develop the fabric to be produced and the design can then be transmitted over the network to the production machines to produce the desired fabric. Now, the design instructions can even be sent by modem from one country to a weaving machine located anywhere else in the world. A weaving machine capable of receiving and responding to instructions in this way can therefore be operated in a developing country, while the designs it is weaving are originated and controlled, long-distance from a developed country.
In the 1990s, due to remarkable progress in computer technology, the application in sizing machines had increased to a greater extent such as multi-point thermo sensors for energy saving, automatic control of squeezing pressure, size pick-up detectors, multi-functional counters, etc. Sizing machine control systems provide a tool for management to insure that all warps are sized identically under standard operating conditions. These monitoring and control capabilities can be included in a computer network of a weaving mill
Online Quality Control
The importance of online monitoring and quality control cannot be over emphasised. With the high rates of production now achievable, any off standard condition can produce large quantities of second grade material. This can represent non-recoverable value added production costs as well as the loss of full priced, first grade products. Should the off-standard material remain in the production line, further deterioration in product quality such as, foreign-matter, broken filaments, slubs or unevenness can be expected in downstream processing. Additionally, machine stoppages can occur. It is essential to incorporate online quality detectors that can measure quality on a continuing basis, adjust machine settings within prescribed tolerances to maintain nominal quality parameters, or stop production if automatic corrections cannot be made.