With the continuous improvement of the material and cultural living standards, the safety of food and medicine has attracted enough attention. The safety of this kind of products is mainly reflected in many factors affecting the quality of products and the health of people, such as drug residues, microorganisms, toxins, metals, heavy metals, preservatives, solid insolubles, etc. in the production process of food and medicine. Therefore, strict control is required for the entire process from raw material collection to product circulation to the market, so as not to cause irreparable damage. In the production process, the damage caused by metal impurities is serious, and it is also an important factor affecting product quality. The wide application of metal detectors not only helps food and pharmaceutical companies to effectively solve this problem, but also becomes an indispensable step in process control.
Hand Held Metal Detector Classification and function of metal detectors There are many types of metal detectors. Commonly used in the market are tunnel metal detectors, free-fall gold detectors, pipeline metal detectors, magnetic induction metal detectors, and walk-through metal detectors. , handheld metal detectors. (The main working principle is shown below)
Walk Through Metal Detector Most metal detectors are composed of two parts, namely the detection head (including the sensor) and the automatic rejection device. The detection head is the core part, which has three coils inside, one central transmitting coil and two equals. The receiving coil fixes the three sets of coils in the detecting head, generates an alternating current alternating magnetic field through an oscillator connected by the intermediate radiating coil, and connects the receiving coils on both sides to make the induced voltage before the magnetic field is undisturbed. Cancel each other out. Once the metal impurities enter the magnetic field: the signals output by the two input coils cannot be cancelled, the
Metal Detector can detect the presence of the metal, and the uncollected induced voltage passes through the sensor, is processed by the control system, and produces a culling signal. Transfer to the automatic reject device to remove metal impurities from the production line.
Door Frame Metal Detector Today's generation of metal detectors proves that innovation in the metal detection industry provides a guarantee for the protection of the company's products from pollution. But there is still a gap between physics and process requirements, even if the zui sensitive metal detector does not guarantee the detection of every metal particle passing through it.
In the pharmaceutical industry, in recent years, due to the continuous improvement of the product quality awareness of end-user enterprises, the GMP certification of the pharmaceutical industry has made corresponding provisions for the online testing equipment of production enterprises. In the process of production and processing of drugs, metal foreign materials such as metal powder, particles, and needle-shaped amorphous materials are often mixed into the product due to wear and tear of equipment, such as negligence, etc., which will affect the safety of the drug, thereby giving the drug manufacturer a reputation. Caused great losses. Therefore, we often use metal detectors to test the product to prevent the presence of metal foreign objects in the product.
Treasure Hunting Metal Detector In the pharmaceutical production process, the more common metal detector application forms are after the capsule filling process, the granule inner packaging, the powder inner packaging and the like. According to the national pharmaceutical industry standards and the relevant provisions of the Chinese Pharmacopoeia: the drug testing project includes the determination of metal limits. Therefore, metal detection is not only a key control point in the production process of food enterprises, but also an indispensable step in the quality of pharmaceutical products in the pharmaceutical industry.
Factors influencing the test results Next, tests were carried out using metal detectors on different processes in the production process. In order to make the results obvious, the test used a Japanese model (1) tunnel metal detector to compare the packaging forms of powder, tablet, bottled products and bagged products of a certain product. The sensitivity of the metal detector is verified by an iron ball of 0.5 to 0.9 Φmm and a stainless steel ball of 1.0 to 1.5 Φmm:
It can be seen from the table (Tables 1 to 4) that the sensitivity of the metal detector is affected by its position in the production line and the packaging form of the product.
The degree of influence of packaging In order to clarify the degree of influence of several kinds of packaging, the centralized packaging of aluminum foil, paper box, PVC, glass bottle, etc. is tested:
It can be clearly seen from Table 5 that aluminum foil has a great influence on the sensitivity of metal detectors, and other materials have almost no effect. In the production process, I can consider changing the packaging form of the product or the position of the metal detector to meet the standard requirements.
Advantages and Disadvantages of Different Detection Locations For the location of metal detectors, consider the rationality of the entire process and the cost of the equipment. Take the tablet as an example to find out the advantages and disadvantages of different locations for production reference (Table 6):
Therefore, in actual production, the proper selection of the type of metal detector and the detection position according to the process requirements are essential for metal inspection work.
The influence of different models From the metal detector itself, the sensitivity of the equipment will affect the results of the test. The following table shows the sensitivity test of several types of metal detectors in Japan and China (in the case of tablet box packaging):
It can be seen from Table 7 that the sensitivity of different metal detectors is different, and the influence on the metal detection effect is also large.
From the above comparison, various factors affecting the sensitivity of the metal detector, the nature of the metal, the nature of the material, and the detection method can be seen. In the actual production process, the metal detector should be properly selected in consideration of the influencing factors (the position of the metal detector, the inspection requirements, the packaging form of the object to be inspected, the sensitivity of the equipment, etc.). After preliminary examinations of domestic and foreign metal detector manufacturers, it was found that metal detection can basically meet different requirements.
The inadequacy and the inadequacy of the improved metal detector is that the instrument will be interfered by different materials during use, so that the error of the result will result in the product being judged to be qualified on the re-production line. For example, some metal detectors are sensitive to aluminum foil, and the result of the error is caused by the material of the package during the inspection.
Due to the insufficiency of metal detectors, it has brought inconvenience to pharmaceutical and food manufacturers to some extent, so it is imperative to make technical improvements. Many manufacturers at home and abroad have developed specific types of metal detectors for different packaging characteristics, and have been widely used.
With the acceleration of the global economic integration process, the gradual improvement of the food and pharmaceutical industry standards, and the increasing precision of electronics and machinery, the requirements for metal detection will increase accordingly. The application of metal detectors has not been limited to the food and drug industry, and has gradually penetrated into all aspects of civil and military industries. Therefore, in order to develop the food and pharmaceutical industries in China, the machinery and equipment manufacturing industry must seize the opportunity to meet the challenges. We will continue to pay attention to the development of metal detectors and their applications in the food and pharmaceutical industries, and contribute to the complete resolution of food and drug safety issues.
March 11, 2019
