The solutions to common problems of needle detectors (needle detectors in English are called needledetectors), each brand has its own manual with its own characteristics, but it boils down to the following common instructions. The testing instrument is a high-precision testing instrument, so the user must follow the following items: Needle detector, which is a ferromagnetic metal induction instrument, is a detection instrument used in the textile industry under the classification of metal detectors. It is mainly used for the detection of ferromagnetic metal foreign objects in textiles. Therefore, the purpose of the development of metal detection equipment is to detect broken needles in textiles. When the needle detector breaks down during use, most of the problems can be solved by itself. Usually there are the following “faults”, please refer to the following common reasons Just deal with it.
First, the dirt on the conveyor belt of the needle detector leads to instrument failure:
Performance: the indicator light on the power-on probe flickers erratically or the conveyor belt runs to a specific part, it will alarm and reverse, and if you put a piece of clothing without any metal, you will find that sometimes it passes through, and sometimes it cannot pass through the needle detector channel. .
Reason: The conveyor belt should be cleaned thoroughly every week. Because the surface of the conveyor belt is often placed on the product and there is a lot of dust from the factory, it is relatively easy to get dirty and must be cleaned regularly. Especially the back of the conveyor belt must be cleaned. Usually, many people only know how to clean the surface of the conveyor belt, but ignore the cleaning of the back. During daily use, dirt containing trace amounts of iron may adhere. If this kind of dirt accumulates, even if the needle is not broken during the detection process, it will react to the dirt on the conveyor belt and cause the instrument to malfunction.
Treatment method: Use a clean towel dampened with water to wring out the surface of the conveyor belt and wear it to the back side for wiping. Until the probe indicator light will no longer flash after starting up and running.
Why does the needle detector react to the iron content in the dirt on the conveyor belt, but the conveyor belt does not stop when it is running without products?
Answer: The needle detector is equipped with a sensor to detect whether there is a broken needle and a photoelectric sensor to detect whether there is a product. When the needle detection sensor is in normal operation, the operation of the conveyor belt is controlled by the photoelectric sensor. That is to say, when the photoelectric sensor does not sense the product (no product is placed on the conveyor belt), even if the needle detection sensor reacts, the conveyor belt will not stop.
The photoelectric sensors are set on both sides of the conveyor belt, with a height of about 5 mm. If the thickness of the product to be detected is very small (for example, less than 4 mm), the product will pass under the sensor beam, and it is impossible to confirm whether there is a product, so the conveyor belt will not stop even if the needle detector responds.
In fact, no matter how thin the product is, the thickness is generally about 7mm. It can be said that the photoelectric sensor can sense all the detected products. However, even if there is iron powder on the conveyor belt, the conveyor belt will not stop due to the above reasons (the instrument is set to finished product In mode C, the thickness of the product should be more than 1.5 cm, otherwise it may cause sensor leakage, which is the so-called light leakage phenomenon).
When it is detected that the conveyor belt is stained with dirt, one of the needle position detection indicators on the mechanical operation panel will light up. When the conveyor belt rotates, the iron powder stained on the conveyor belt will fixedly light up on the same part of the conveyor belt to indicate that foreign objects are detected. At this time, only cleaning the conveyor belt can eliminate the fault.
Malfunction caused by external noise:
Put the inspected product on the conveyor belt of the needle detector, if the noise disturbs the magnetic field of the needle detector from the outside when the product moves near the needle detector sensor, the machine will stop conveying the inspected product and sound the display.
The external noise has the following situations.
Electromagnetic clutch motors in the workshop, sewing machines, cutting machines, packaging machines, large transformer decontamination spray guns, ironing table motors, elevators, large fans, large moving objects such as railways outside the workshop, transformers, welding machines, high-voltage lines, etc., and used by operators When using the needle detector, do not carry mobile phones, keys, watches and other metal objects. These equipment and objects may cause false alarms of the needle detector. In addition, when the needle detector is working, avoid carrying metal hangers passing by.
When there is a large fan on the upper part of the needle detection machine, the power must be turned off when the needle detection machine is working. When the source of the noise in the workshop cannot be determined, for example, when the power of the needle detector is turned on and the operation switch is turned off, if the display lights up in red, it can be judged that it is affected by external noise. At night or when all the power in the workshop is turned off, only the needle detector power is turned on. If there is no noise impact, it can be judged that there are other problems in the production of the workshop. Then, in the same state, start the mechanical equipment that may be affected one by one to find out the cause.
Third, malfunction caused by internal noise The internal noise of the needle detector comes from the noise or vibration generated by the needle detector itself. First, please fix the anchor bolts at the bottom of the machine so that the rollers are off the ground. If the ground bearing capacity is weak, the machine will vibrate and cause malfunctions. Please lay a 20cm square plate under the bottom bolts to reduce the vibration of the machine body.
It is necessary to confirm whether the fixing screws of each part of the needle detector are screwed on properly. Loose component screws will cause vibration to be transmitted to the needle detection sensor, which will also cause mechanical malfunction. Magnetization of bearings used in machinery can also cause malfunctions. The magnetism on the bearing must be eliminated with a demagnetizer.
The fourth malfunction caused by defective products:
In the products of the operation, sometimes the needle detector will react due to the different types of dyes. For example, in the case of a certain color, it can almost pass through the needle detector, but in other colors, the phenomenon that it cannot pass is because some dyes contain iron oxides. Replace it, and the needle detector can be used normally. Also, the rubber used for the bottom of footwear often contains a lot of metal powder. In this case, there are no metal fragments such as broken needles in the inspected product, but because it contains a lot of tiny iron, the conveyor needle detector will also respond to the overall metal content. At this time, the abnormality of the product may not always be detected with a portable needle detector. Because the portable needle detector is pressed against the product to be inspected for detection, it can detect smaller foreign objects than the conveying needle detector. However, in the above case, although the portable needle detector has a relatively high sensing intensity, the needle detection area is very small, and the reaction area of the sensor is even smaller, so the phenomenon that the portable needle detector cannot detect foreign objects often occurs.
In addition, if garments and other sewn products use metal accessories, first ensure that the accessories (metal zippers, metal buttons, metal bead chains, etc.) do not contain the three magnetic metal components of iron, cobalt, and nickel. If the content of accessories reaches a certain level, it will not pass the inspection of the needle detector, and it will also cause the “failure” phenomenon that the sewn products with these accessories cannot pass the needle detector.
Fifth, the magnetic force of the magnetic steel is weakened:
The needle detection sensor of the needle detection machine uses permanent magnetic steel, but after many years of use, the magnetic force of the device will gradually decrease. If it is found that the use year has reached more than six years (some small manufacturers use inferior magnetic steel needle detectors with a shorter service life), after eliminating all faults, if the sensitivity of the needle detector still cannot be adjusted back to the original sensitivity, it is necessary to ask the manufacturer to carry out Repair and replace magnets.
Jiangsu Suzhou Rehow Machinery Co., Ltd. specializes in the production of textile machinery and equipment, which integrates research, design, production, marketing and service. It has a strong technical force, and constantly introduces domestic and foreign technologies, with reliable product quality and stable system. The company uses imported raw materials and component supporting products. The product range of REHOW textile machinery covers almost all types of fabrics, including but not limited to needle detectors, hank machines, looms, looms, warping cars, cloth cutting machines, electric Warping car, warping warehouse, slitting and slitting machine, coiling machine, ultrasonic slitting machine, opening width machine, cloth inspection machine. REHOW Textile Machinery continues to lead the textile industry with its innovative approach and rich experience. We welcome offers and partnership opportunities with open arms!
Post time: May-30-2023
