On the development of pneumatic technology in food packaging machinery

After nearly 20 years of development, China's food packaging machinery has formed a certain scale and has become an important part of the machinery industry. At present, most of the packaging work in domestic food processing, especially the more complicated packaging process is basically manual operation, which is likely to cause pollution to the packaged products. This situation needs to be changed. At present, the country is stepping up efforts to implement the food quality and safety market access system, and food packaging equipment is also gradually being incorporated into the food quality and safety access system. This is a good opportunity for the food packaging machinery industry to achieve industrial upgrading. Modern food packaging machinery is a collection of advanced technologies in many disciplines, with high efficiency, high precision, high automation and high flexibility, and is developing in the direction of intelligence and integration. One of the basic components is pneumatic technology .

Pneumatic technology is one of the effective means of production process automation and mechanization. It has the advantages of high speed, high efficiency, clean safety, low cost, and easy maintenance. It is widely used in the field of light industrial machinery, and is also being used in food packaging and production processes. More and more important role. It has a large number of applications in various types of packaging machinery, which can shorten the processing auxiliary time, reduce the labor intensity of workers, and give full play to the efficient performance of the equipment.

However, because food packaging machinery must meet the relevant requirements and regulations of food machinery safety, and the work site environment is generally more complicated and harsh, if inappropriate pneumatic components are used, abnormal phenomena often occur. The modern food packaging machinery usually integrates mechanical, electrical, hydraulic and pneumatic technologies, and there is an inseparable connection between each part. Any part of the failure will affect the normal operation of the equipment. Therefore, in the design and application of the pneumatic part of food packaging machinery, we must choose reliable and practical products.

In food production, the hygiene requirements of different production areas are different. The European EN1672-2 standard defines the environment of food processing machinery as 3 working areas, namely food area, splash area and non-food area. According to the hygienic requirements of different regions, the pneumatic technology and products required are also different.

Food and splash areas require safety and hygiene

In the food area and splash area, pneumatic technology is mainly used in dispensing, bottling, forming, filling, dispensing and sealing devices. Because the pneumatic components need to be directly or indirectly in contact with the main production materials, in order to avoid pollution of the final product , The material should be non-toxic, non-absorbent and corrosion-resistant stainless steel original. If aluminum alloy materials are used, they should have certain corrosion resistance, no toxicity, and no absorption. The rubber products used inside the components, such as seals, should meet the corresponding hygienic requirements, should have the characteristics of heat resistance, acid and alkali resistance, and oil resistance, and can be cleaned and disinfected normally. Affect the smell of the product. The working air filter device should ensure that no dust above 5μM is allowed to pass through, and the structure and surface should be smooth, durable, easy to clean and can achieve a good cleaning effect. Although the design of the splash zone needs to be similar to the food area, the material requirements can be reduced as appropriate, and it must be ensured that the design has no negative impact on food products.

Typical pneumatic products used in these two environments are stainless steel cylinders, clean cylinders, easy-to-clean valve islands, stainless steel filters, and pressure relief valves. The most representative of these are clean cylinders, such as PVA from NORGREN in the United Kingdom. Series of clean cylinders. The clean design of this cylinder eliminates the cavities, gaps and sharp edges that food particles may adhere to. It has a self-draining function, so the liquid can flow directly. The cylinder is made of anodized aluminum, the piston rod is made of hard-coated stainless steel, and the seals used are made of polyurethane. The cylinder as a whole conforms to the requirements of IP67, which is not only resistant to corrosion, but also can be repeatedly cleaned. In addition, the cylinder is a standardized product conforming to ISO6431, which is replaceable. Even the installation parts are also standard parts, which are extremely convenient for installation and maintenance.

Non-food zone components have increasingly strict size requirements

In non-food areas, pneumatic technology is mainly used in devices such as bag sealing, packaging, labeling, testing and capping. Although the pneumatic components in this area do not need to contact the production materials, they usually still need to be standardized, easy to clean, intelligent and environmentally friendly. And compact structure. Since the current food packaging equipment requires more functions in a limited space, the size requirements for pneumatic components are becoming more and more strict. Typical products include the British NORGREN easy-to-clean valve island VM series as shown in Figure 2. The valve body with a width of only 10MM can provide a flow of 430L / MIN, can be integrated from 2 to 20 positions, and meets IP65 and complex control in food packaging the trend of. In addition, advanced food packaging equipment generally uses a non-lubricating pneumatic system composed of filters, pressure relief valves and non-lubricated valves and cylinders. This system is pre-sealed with grease at the point where components need lubrication, no oil is required The atomizer can work for a long time without replenishing grease, can reduce fuel consumption and cost, improve the environment, easy maintenance and stable performance.

Intelligent pneumatic device

With the increasing improvement of food processing technology, the automation level of food packaging is also constantly improving. At present, the research and development of food packaging machinery is developing in the direction of high speed, multi-function and intelligent control. Industrial robots, microelectronics, computers, intelligent And image sensing technology will be more and more widely used, and the intelligent and networked pneumatic technology used in food packaging machinery will become inevitable.

The intelligent cylinder is the master of intelligent cylinder. Take the intelligent cylinder of NORGREN as an example. This cylinder has built-in solenoid valve and quick control valve. The cylinder provides FIELDBUS and ASI interfaces, which can realize remote centralized control of the bus. It has IP66 protection grade and is easy to wash; it also conforms to ISO / VDMA standards and can be interchanged with ordinary standard cylinders. Using this cylinder can replace the entire traditional pneumatic circuit.

The intelligent pneumatic triplet makes self-diagnosis of the air handling system possible. Most pneumatic system failures are caused by the air handling system. The intelligent triplet effectively solves this problem. It can continuously monitor the pneumatic system and display related data through the FIELDBUS and ASI connection at any time to inform when it is necessary to replace the filter element or lubricant, whether the pressure status is normal, and record the use time, so as to minimize the failure rate and reduce maintenance. Cost, improve uptime and production capacity.

The development and application of intelligent and networked pneumatic technology will make food packaging machinery more intelligent and realize self-diagnosis of equipment, thereby improving the automation level of domestic food packaging machinery.