The latest weaving machines are equipped with microprocessor or PLC units which ensure continuously the control, the drive and the monitoring of the various machine members and of the various functions.
A variety of electronic devices and sensors permits the collection and the processing in real time of the main production and quality parameters. These parameters can also be recorded and transferred through memory cards to other machines or stored for future use (fig. 1). The control unit can be connected with outer units (terminals, servers, company managing system) to transmit/receive data concerning both the technical and productive management and the economic-commercial management (fig. 2). All this facilitated considerably the weaver’s work in respect to machines of previous generation, and enabled to improve the production yield and the product quality.
Fig. 1 − Board computer equipped with memory card
Fig. 2 − Example of a modern monitoring and control network
The main operations which can be carried out by simply keying in the value of the desired parameter on the keyboard of the electronic control unit are:
• selection and modification of the weft density with running machine, as both the motor driving the take-up roller (sand roll) and the motor driving the warp beam are electronically controlled and synchronized one another. This permits also to combine a programmed automatic pick finding, obtained through correction programs based on the characteristics of the fabric in production, in order to prevent formation of starting marks (after machine stops); • electronic selection and control of warp tension through a load cell situated on the back rest roller, which last detects continuously the tension value. This permits the processor to control the movements of the warp beam and of the take-up roller, ensuring a constant tension throughout the weaving operation (fig. 3);
• programming of the electronic dobby and of the electronic weft colors selector;
• programming and managing of nozzle pressure and blowing time in air jet weaving machines;
• selection and variation of the working speed, as the machines are provided with a frequency converter (inverter) which permits to modify at will the speed of the driving synchronous motor;
• managing/programming of all machine functions.
Fig. 3 − Electronic detecting and control system on thread tension. Setting and modification of tension and weft density directly via board computer