Beta Computronics Private Limited

It Park, Nagpur, Maharashtra

Weft Break Sensor (Magnetic Sensor) : for detecting tape Breakages

The Magnetic Loom Sensor is an highly sophisticated and reliable device to sense the weft breakage, empty bobbin, and uneven weft tension in Circular Loom. The sensor is heavy-duty type and suits for environmental conditions of Plastic Woven sacks Industry. The sensor works on the principle of magnetism, there by eliminating the problems like dust, ambient light, reflection of fabric which are prominent in light based sensors. The sensor is totally sealed and hence, virtually no maintenance is required in day-to day operations. The design of sensor is such that, installation is very simple and requires fitting of boom reflector assemblies (with magnets fitted in place of diamond) on boom pipe, mounting of sensor on the loom and fitting of relay card in panel. The magnets are arranged in such a way that North and South poles of the magnets comes under sensor alternately avoiding magnetization of sensor.

The 3-core wire from sensor connects to relay PCB. When shuttle bobbin runs out of the tape or if the shuttle tape breaks, then magnet rotates and comes under magnetic sensor, this magnetic field is sensed by sensor, and relay is energized. The contact of the relay stops the loom and cramming is started. The sensor can be used on other types of loom also with modification in Magnet Holder. We have already developed the magnet holder for different make of loom. We can also design the magnet holder assembly for any other type of Loom.

Who is it for

• For Circular Loom of Woven Sack Industry.
• A reliable and dependable option for Photo Cell.
• Zero wastage due to tape breakage in shuttle bobbin
• Works on magnetic principle
• Full Utilization of shuttle bobbin
• Single operator can handle multiple loom
• Increases loom efficiency
• Increases Quality of fabric
• Fast pay back
• Non Polarized type

The Advantages of Sensors

• The shuttle bobbin can be completely utilized hence it is not necessary to put it on creel stand for further use.
• As smaller bobbins removed from shuttle are not loaded on creel, the creel stand can be loaded with large size bobbin and frequent stoppage to change creel bobbin is avoided.
• One operator can handle multiple loom as he does not have to monitor the shuttle bobbin constantly.
• The wastage due to tape breakage in shuttle bobbin is totally avoided, as loom stops (with cramming if enabled), immediately if tape breaks.
• As the Sensor is based on magnetic principle, the effect of dust and calcium carbonate is nil. The Sensor does not requires any maintenance.
• The efficiency of loom increases and quality of fabric is also improved as loom stops even if the shuttle tape isslightly loose.
• The pay back of the system is fast due to more production, improved quality, less down time of the loom and reduced wastage.

The circular Loom used in woven sack industry has 48 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.

The Weft sensor is a highly sophisticated and reliable device to sense the weft breakages, empty bobbin, and uneven weft tension of shuttle in Circular Loom. The design of sensor is heavy - duty type and suitable for environmental conditions of Plastic Woven Sacks Industry. The sensor works on principle of magnetism, thereby eliminating the malfunction due to dust, ambient light, reflection of fabric, which are prominent in light based sensors. The sensor is totally sealed and hence virtually no maintenance is required in day-to-day operations, if setting is not disturbed. The installation is very simple and requires fitting of boom reflector assemblies (with magnets fitted in place of diamond) on boom pipe, mounting of sensor on the loom and fitting of relay card in panel. The magnets are arranged in such a way that north and south poles of the magnets come under sensor alternately, avoiding magnetization of sensor. The 3 - core wire from sensor connects to Relay PCB. When shuttle bobbin runs out of the tape or if the shuttle tape breaks, then the magnet rotates and comes under weft sensor. This magnetic field is sensed by sensor, and Relay is energized. The contact of the Relay is wired to stop the loom and missing tape is compensated by cramming the fabric. Cramming device avoids gap due to missing tape.