The circular Loom used in woven sack industry has 4–8 shuttle bobbins which provides the weft tapes to circular fabric. If this tape breaks, the fabric is wasted as it contains lots of missing tapes. Our Weft Break sensor has been used widely to detect these types of breaks and avoiding the wastage of fabric.However there has been great demand for detection of near empty condition of shuttle bobbin, so that bobbin can be changed before it is completely empty. This results in zero defect fabric. Usually to achieve this all the shuttle bobbins are replaced at once, even if they are not empty. This results in lot of tape wastage on 'Not so empty bobbins'. Our bobbin sensor is designed to detect the near empty condition of bobbin. When the sensor detects the near empty condition of bobbin, the sensor stops the loom, so that only that particular bobbin can be changed. This not only results in Zero defects Fabric, but also Zero wastage on bobbins also.

The bobbin sensor is a highly sophisticated and state of the art sensor to detect when shuttle bobbin nears empty condition. The sensor is based on Infra Red to detect the presence of tape on bobbin, and a powerful, fast microprocessor which calculates various timing and detects the near empty bobbin and sends the trip signal to relay PCB. The relay PCB stops the loom by opening the NC contact which is in series with Loom Stop button. As the sensing mechanism is based on infra red principal, color of shuttle bobbin tape and base color of empty bobbin may affect the performance of sensor, however sensor will work faithfully on Light color tape and all mild steel bobbins.

The installation of bobbin sensor is straight forward. The distance between sensor and shuttle bobbin(with about 1 mm of tape on it) should be around 140-160. The LED on the top of of sensor provides useful information. The functions are as under.

1. White LED - This LED lights up when a bobbin is under the sensor and it is sensed. (When bobbin comes under sensor, this LED lights up). During normal operation when loom is running , this LED will be ON continuously indicating that all the shuttles are sensed and no shuttle is near empty. If the white LED flashes while loom is running, it indicates that one of the bobbin is not sensed or it is near empty or completely empty. In this condition a stop signal will be generated by bobbin sensor and the loom will be stopped. If this is not the case please refer to troubleshooting section.
2. Red LED - During normal loom running condition, when white LED is ON, and if any of the bobbins is near empty condition ,this LED will be ON briefly for approximately 2 seconds and will stop the loom by giving signal to relay PCB. The loom should stop immediately after the stop signal is generated. If loom do not stop please refer to troubleshooting section.