Pneumatic technology is one of the effective means to realize automation and mechanization of production process. It has the advantages of high speed, high efficiency, clean and safe, low cost and easy maintenance. It is widely used in the field of light industrial machinery and is also playing a role in food packaging and production. More and more important role.

Typical pneumatic products used in food and splash zones

Figure 1. Typical pneumatic products used in food and splash zones: stainless steel cylinders, clean cylinders, easy-to-clean valve islands, stainless steel filters, pressure reducing valves, etc.

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 very likely to cause pollution to the packaged products, and this situation needs to be changed. At present, the state has stepped up efforts to implement the food quality and safety market access system, and food packaging equipment is 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 a variety of disciplines, featuring 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 automation and mechanization of production process. It has the advantages of high speed, high efficiency, clean and safe, low cost and easy maintenance. It is widely used in the field of light industrial machinery, and is also playing a role in food packaging and production. The more important the 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 high efficiency of equipment.

However, since food packaging machinery must comply with the relevant requirements and regulations for food machinery safety, and the work site environment is generally more complicated and demanding, if improper pneumatic components are used, abnormalities often occur. Modern food packaging machinery usually integrates mechanical, electrical, hydraulic and pneumatic technologies, and each part has an inseparable connection. Any part of the failure will affect the normal operation of the equipment. Therefore, in the design and application of the pneumatic part of the food packaging machinery, it is necessary to select a reliable product that meets the actual needs.

UK Norgren easy to clean VM series valve island

In food production, the hygiene requirements vary from one production area to another. The European EN1672-2 standard defines the environment for food processing machinery as three work areas, namely food, splash and non-food areas. According to the hygiene requirements of different regions, the pneumatic technology and products required are also different.

Food and splash areas require safety and hygiene

In the food and splash zones, pneumatic technology is mainly used in distribution, bottling, forming, filling, dispensing and sealing devices. Since pneumatic components need to be in direct or indirect contact with the main production materials, to avoid contamination of the final product. The material shall be non-toxic, non-absorbent and corrosion-resistant stainless steel originals. If aluminum alloy material is used, it should have certain corrosion resistance, no toxicity and no absorption. The rubber products used inside the components, such as seals, shall comply with the corresponding sanitary requirements. They shall have the characteristics of heat resistance, acid and alkali resistance and oil resistance. They are acceptable for normal cleaning and disinfection, insoluble, non-toxic and non-absorbent. Affect the odor of the product. The working air filter device should ensure that dust above 5μm is prohibited, and the structure and surface should be smooth, durable, easy to clean and achieve good cleaning effect. Although the design of the splash zone needs to be similar to that of the food zone, the material requirements may be reduced as appropriate, and the design must be guaranteed to have no negative impact on the food product.

Typical pneumatic products used in these two environments are stainless steel cylinders, clean cylinders, easy-to-clean valve islands, stainless steel filters and pressure reducing valves (Fig. 1), and the most representative of these are clean cylinders, such as Porg series clean cylinders from Norgren, UK. The clean design of this cylinder eliminates cavities, gaps and sharp corners where food particles may adhere, and has a self-draining function so that the liquid can flow directly away. The cylinder material is made of anodized aluminum, the piston rod is made of hard-coated stainless steel, the seal used is polyurethane material, and the whole cylinder meets the requirements of IP67, which is not only corrosion-resistant, but also can be repeatedly cleaned. In addition, the cylinder is a standardized product conforming to ISO6431, and it is replaceable. Even the mounting parts are standard parts, and the installation and maintenance are extremely convenient.

Norgren's intelligent pneumatic triplex

Non-food area components are increasingly demanding in size

In non-food areas, pneumatic technology is mainly used in packaging, packaging, labeling, testing and capping. Although the pneumatic components in this area do not need to be in contact with the production materials, they still need to be standardized, easy to clean, smart and environmentally friendly. And compact structure and so on. As today's food packaging equipment requires more functionality in a limited space, the size requirements for pneumatic components are becoming more stringent. Typical products include the UK Norgren easy-to-clean valve island VM series as shown in Figure 2. The valve body with a width of only 10 mm provides 430 L/min flow, 2 to 20-position integration, and IP65 and complex control in food packaging. the trend of. In addition, advanced food packaging equipment generally uses a non-oil-lubricated pneumatic system consisting of a filter, a pressure reducing valve and a non-oil-lubricated valve and cylinder. The system is pre-sealed with grease in the parts where lubrication is required, no oil is required. The mister can work for a long time without replenishing grease, which can reduce fuel consumption and cost, improve the environment, and is easy to maintain and stable.

Intelligent pneumatic device

With the increasing 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, and intelligent types. And image sensing technology will be more and more widely used, and the intelligent and networked pneumatic technology applied to food packaging machinery will become inevitable.

Intelligent cylinders are the masters of intelligent cylinders. Take Norgren's intelligent cylinders as an example. These cylinders have built-in solenoid valves and speed control valves. The cylinders provide Fieldbus and ASI interfaces for remote centralized control of the bus. It is IP66 rated and easy to flush; it is also ISO/VDMA compliant and interchangeable with standard cylinders. This cylinder can be used to replace the traditional entire pneumatic circuit.

The intelligent pneumatic triplex (Fig. 3) makes self-diagnosis of the air handling system possible. The failure of most pneumatic systems is due to the air handling system, and the intelligent triplex effectively solves this problem. It can continuously monitor the pneumatic system and display relevant data through Fieldbus and ASI connection at any time to inform when it is necessary to replace the filter element or lubricating oil, whether the pressure state is normal, and record the usage time, so as to minimize the failure rate and reduce maintenance. Cost, increase uptime and productivity.

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