Drive improves dye processing quality

A new control system, featuring an ABB variable speed drive, is said to efficiently manage tension control and the changing size of the fabric reel, as it traverses through the dyeing process.

“The VSD’s in-built PID loop allows the system to automatically match torque to the requirements of the running fabric based on the thickness and number of wraps,” says ABB. A more consistent distribution of dye in clothing and furnishing fabrics has resulted from replacing a hydraulic control system with the VSD, while also helping reduce the process’ annual energy bill by £1,900.

The dyeing machine – known as a jigger –is operated by DP Dyers of Huddersfield. It comprises a winder that feeds the fabric into the dye and a rewinder that gathers the finished product. The winder and rewinder were both controlled by an ageing hydraulic system, the motors of which suffered regular breakdowns. The hydraulics lacked the speed and accuracy of control needed by the winder/rewinder, resulting in uneven dye distribution, according to DP Dyers.

Constant tension

A 5.5 kW ABB industrial drive was recommended by Halcyon Drives, one of the ABB Value Provider network. The VSD ensures a uniform dyeing or bleaching process by maintaining a constant tension in the wound fabric as the diameter of the reel changes.

The VSD uses its in-built PID loop to calculate the torque needed to manage the tension of the fabric running between the winder and rewinder. Meanwhile, the VSD determines the required speed of winding, based on the material thickness and the number of turns of fabric, or wraps, on the lead roller.

The system drives the fabric onto a roller and counts the number of wraps. The operator measures from the outside wrap to the core and inputs this to the VSD. The VSD then calculates the fabric thickness based on the outside diameter divided by the number of wraps.

More consistency

Robert Clay, site engineer for DP Dyers, comments: “We are getting a much more consistent product, with more even dyeing. This is due to the VSD, which constantly adjusts the web speed and torque to maintain the correct tension. The control system is now much more user friendly, with the software giving the alarm history of jobs. Now we have much more data, showing a history of temperatures and times of operation.”

Prior to installing the VSD, the machine’s weekly energy consumption was typically 597 kWhr, costing around £50. Following installation, this reduced to 169 kWhr and £14 respectively, a reduction of around 70%.