COMPUTERS AND AUTOMATION IN WEAVING

School of Science & Engineering, Department of Textile Engineering

Southeast University

COMPUTERS AND AUTOMATION IN WEAVING

Md. Fazley ElahiAssistant Professor


Dept. of Textile Engineering



Computers and AutomationIntegrated artificial intelligence is incorporated in most of the modern weaving machines. Modern electronics with microprocessors, integrated in the machine, monitor, control, regulate and

optimize all major weaving machine functions. The central microprocessor monitors and controls the weaving process. The touch screen terminal is used as the interface between the operator and the machine. The

terminal acts as the interface between personnel and the machine. Corresponding to the varying information requirements, the microprocessor control provides specific terminal functions for operators, supervisors and managers. Setting data may be transferred from one machine to another with a memory card. If no setting data is available for a style which had not been woven previously, the microprocessor can calculate standard parameters from the entered fabric specification and transfer them automatically to the electronically controlled function units. Two-way communications with production management systems or production data collection systems are possible with suitable interfaces.

Md. Fazley ELAHI 2Computer & Automation in Weaving



Today's modern weaving machines offer high operational reliability with centralized microprocessor control. These operations were included in the previous chapters for each particular machine. Some examples of automation and electronic control are:

Electronically controlled warp let off provides constant warp tension. Electronically controlled cloth take-up maintains the accurate cloth weight. Electronically controlled color selection allows picking of multifilling colors. Electronically controlled yarn brake reduces filling breaks and waste and provides constant filling tension. Menu guided operation at the terminal assists the Quick Style Change. Interfaces for two-way communication with modern systems for plant management and production data collection.




Programming and Archiving Systems

Weaving machine manufacturers developed user friendly programming and archiving systems for the weave room. With these systems, the pattern data and the machine settings can be programmed in the office with the aid of a PC from where they are transferred onto the machine. These systems offer the following advantages:

shortening the resetting and cycling times increasing efficiency improving reproducibility




Electronic Spare Parts Catalog

Today, weaving machine manufacturers provide spare part catalogs in electronic formats such as CD-ROM. A CD-ROM weighing 20 g and featuring a diameter of 12 cm can store information of a catalog comprising of some 13,000 pages of paper, weighing 50 kilograms. From an ecological point of view, this new development offers a big advantage.




Electronic Direct Ordering System (EDOS)

The just-in-time philosophy is becoming increasingly evident and manufacturers are reducing their spare part reserves to absolute minimum levels. With today's modern, capital intensive and highly productive weaving machines, the cost of lost production is much higher than that incurred for spares. Furthermore, the requirement which depends on the employed raw weaving materials and external influences can be very irregular. The consequences are shorter deadlines with greater responsibility, which can only be overcome by tightening up the flow of information and material between the customer and the supplier.




Electronic Direct Ordering System makes it easier for customers to order parts and supplementary parts. The electronic transfer of data servants’ transmission errors and offers the assurance that the customer will quickly receive the correct parts. The system accelerates and channels the flow of information and goods of an order on its way from the customer to the supplier and back again. For the electronic ordering of spare parts, the customer needs a commercial type PC, a modem, a printer and the necessary software.With the EDOS systems, the customer can receive complete, up-to-date and accurate information quickly. The high transmission quality is also beneficial. Ultimately, the customer receives his urgently required parts quicker: the order cycle is reduced. The electronic processing of the order data reduce the possibility of typographical and transmission errors. The customer does not have to enter and check the majority of the data with each other. The simplified book keeping and order monitoring leads to reduction in cost.




The customer selects the parts that he wishes to order from the standard set of data; he sees all the necessary data and complements them with the required amount and mode of delivery. The data are then transmitted by modem to the subsidiary and passed onto the head office. After a short time and along the same route, he receives the confirmation of order, with price and information concerning the readiness for dispatch. He knows already that he will receive the right parts and when he can expect them.




Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM)

Today's CAD/CAM technology allows transmission of fabric design from computer screen to the machine. CAD/CAM saves product development and manufacturing time, provides quicker response with good accuracy and quality. Pattern changes and modifications are done easier and quicker. There are various configurations and setups of CAD/CAM systems. As an example, in one configuration for woven terry fabrics, the artwork produced by a stylist is scanned into a workstation. Then, the design parameters are entered for a specific fabric style. Parameters for each fabric style are stored in a database. The scanned-in artwork is edited and a weave is selected from a database. Colors are displayed on the computer screen. The pattern file developed is digitized and stored in a diskette for subsequent downloading into the jacquard machine controller on the weaving machine. Through the workstation-printer interface, assimilation of the fabric can be printed out. Thus, the terry towel can be seen in virtual reality




In a more scientific approach, CAD of fiber, yarn and fabric simulations can be done based on mathematical and physical principles. Thin and thick places and other irregularities can be represented in the yarn depending on the simulated manufacturing model. Using the 3-D image of the yarn, the resulting woven fabric can be simulated. Visualizing the physical characteristics of yarn on the screen before the yarn is manufactured provides significant advantages in reducing R&D and prototype manufacturing time of fabrics. The manufacturer can determine the suitability of a yarn in a fabric a lot faster with less cost. Even the wash down effects on fabrics can be simulated with computers.




With the growing demands made on fabric quality and efficiency of the weaving machines, their functionality rests increasingly on electronics and information systems along with mechanics. Today, fabric design is developed on the computer and transferred to the weaving machine in a memory card.

The building blocks of such a CAD/CAM system are as follows:Weaving Data Archive:o managing and archiving all weaving data recordso creating new weaving datao Interface for importing new pattern data from various CAD programs.




Weaving Data Record:

Diagrammatic representation of harness frame and color control as well as special functions. Numeric representation of filling density and pile height developing and modifying pattern data as:

o pattern for card punching (also electronic)o color patterno special functionso electronically controlled cloth take-upo dynamic pile control




Parameters:o Programming of the electronically controlled functional units on the weaving

machine developing or modifying the electronic machine settings aso warp let-off functionso data for the electronically controlled filling yarn brakeo controlled fabric fell correction




Data Transfer:

Transferring the weaving data to the memory card (MC) or back with the aid of the data carrier, the weaving data are transferred to a memory card. After the memory card has been loaded with one or more sets of weaving data, the memory card is passed on to the weave room staff who transfer the data to the weaving machines by means of the data carrier. After fine optimizing of the weaving data on the machine terminal, the data can be archived in the PAS via the data carrier, thus ensuring the reproducibility of the fabric quality.




Computer Based Training

Today's fast and powerful computers enable multimedia-based training programs. These programs allow improvements of the quality standard, motivation of the staff members as well as reduction of training costs. Multimedia based training offers the possibility of passing on knowledge within the industrial sector with large quantities of visual material. The computer based training (CBT) system teaches operation and maintenance of the weaving machine by means of full-screen video, animation, audio, pictures, diagrams and text. It enables job targeted learning and the material taught can be immediately rested on the machine. It is also possible to repeat such exercises as often as necessary and each student is given the same explanation, irrespective of the environment.




Computer Based Training (continued)

Comprehensive training courses can thus be considerably shortened. Function, operation and maintenance of the weaving machines are presented in an effective way, since the students have normally no opportunity to watch these on the machine. The entire material is stored on CD-ROM disks and can be adapted individually and customer-specifically on training PCs. The interactive CBT can be used at anytime and anywhere, independent of the instructor, be it on the machine the office or at home. Service and sales engineers can take CBT with them in their hand luggage. The modular structure of the CBT system affords learning in appropriate steps. The students are able to call the individual learning steps and to repeat them as often as they wish, without specific PC experience. Concerning presentation, they can choose between video film, animation or still photography, each one accompanied by spoken text.




Computer Based Training (continued)The latter can be displayed and printed. A multitude of test and qualification possibilities enable detailed control of the learning success. The lecturer who is responsible for the training obtains an up-to-date and objective survey on the learning success of all participants of the course, who, in turn, have the possibility to watch the actions carried on the machine through laptop PC. Even though the preparation of CBT programs involves considerable expenditure, the overall costs for the entire learning package are far below those for training the customer personnel in the conventional way.




Computer Based Training (continued)For CBT training, a PC configuration is required on which CD-ROMs can be run. Several PCs can be networked with each other. A training manager supervises the learning progress of the trainees. An advantage of CBT is that it is always available when necessary and when there is time for learning. CBT constitutes a tool that enables internationally active enterprises to train their coworkers and customer employees, on a global basis, with always the same standard. This guarantees that each production location delivers the same product quality.




Technology Support Centers

Some weaving machine builders are offering technical support to their customers through feasibility studies, weaving trials, etc., in research weaving facilities. Service and customer weaving trials are conducted in these facilities.With the weaving trials, fiber and yarn manufacturers can determine whether or not, and at which weaving machine speeds, the desired styles can be optimally produced on the weaving machines. In these research centers, new fabrics can be developed and weaving problems can be solved.




The filling insertion trials reveal the expected frequency of filling stoppages as well as the suitability of the yarn for the corresponding type of weaving machine. The yarns and fabrics are inspected for possible defects as well.Machine manufacturers also help customers to meet the new demands with the existing machinery. They provide services and studies for retrofitting, conversion, customer oriented solutions for special equipment, special fabrics and accessory and auxiliary components. The following changes of machine specifications are demanded most frequently:

conversion from single pick to weft mixer increasing the number of harnesses conversion from dobby to jacquard machine equipment for heavy fabrics increasing the warp beam diameter


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COMPUTERS AND AUTOMATION IN WEAVING