The use of pneumatic tubes in food processing automation and robotics presents significant challenges in hygiene, durability, performance and maintenance. The antimicrobial and hydrolyzed pneumatic tubing also features kink resistance, which simplifies and accelerates the installation of automation and robots and improves long-term reliability.
Other desirable features of pneumatic tubing in food processing applications include exceptional flexibility, suitability for use in the energy chain, ease of installation and removal for reconfiguration and maintenance with quick connectors, and a variety of color options, including transparent tubing for monitoring system status.
The airway material must be resistant to chemical disinfectants and high pressure high temperature flushing used in food processing and must comply with all FDA requirements.
This paper details how Festo's PUN-H pneumatic tube meets the large demands of automation equipment and robots in the food processing industry.
Manufactured from modified polyurethane, PUN-H pneumatic tubes are versatile and support small bend radii, making them ideal for compact installations. Polyurethane is inherently resistant to hydrolysis and FDA certified for use in food production processes.
The flexibility of PUN-H makes it suitable for general pneumatic applications in mobile parts (e.g. energy chains), biotechnology, pharmaceutical and cosmetics industries, as well as standard applications in the automotive, electronic and chemical industries.
PUN-H air pipes are available in a variety of colors and transparent versions (Figure 1). Standard colors include blue, blue/black, yellow, green, natural, red, silver, and black. It is also available in translucent versions, including blue, yellow, green and black.
FESTO PUN-H PNEUMATIC TUBE IMAGE 1: FESTO PUN-H PNEUMATIC TUBE is available in a variety of colors and transparencies. Picture Source: Femto)
The black PUN-H air pipe is UV resistant and suitable for outdoor applications. The transparent air pipe allows the machine operator to immediately know the quality of the compressed air. Pollutants such as particulates, water or oil are readily detectable. For example, the presence of condensate indicates moisture in the system. Moisture is not acceptable in most food processing safety standards. It also shortens the life of the pneumatic components.
The PUN-H gas pipe is designed for conveying compressed air, vacuum and water. The ambient operating temperature range is - 40 ° C to+60 ° C. The operating pressure range varies with temperature. Max. rated pressure 1.0 MPa (10 bar/145 psi) for temperature range - 35 ° C to+30 ° C. The maximum pressure specification drops to 0.6 MPa (6 bar/87 psi) in the high temperature range of+30 ° C to+60 ° C.
It is available in nine sizes, with outside diameter (OD) ranging from 2 mm to 16 mm, and the length of the coil varies depending on the outside diameter of the gas tube. For example, PUN-H-3X0, 5-BL-500 models have an outside diameter of 3 mm and a standard length of 500 m. The outer diameter of PUN-H-12X2-SW-200 is 12 mm and the standard length is 200 m. DigiKey can custom cut short lengths of tubing.
The use of a modified polyurethane material is the reason for the high flexibility and flexibility of the PUN-H gas pipe. They are more flexible than other materials and do not wrinkle or permanently distort.
The inherent flexibility of PUN-H makes it easy to install in confined spaces, thus reducing the machine and mounting dimensions. This material is resistant to hydrolysis and cracking, ensuring durability and reliability. FDA approved food grade modified polyurethane is resistant to microbes and is highly resistant to cleaning agents, making it ideal for food processing and packaging systems that are often in contact with water.
Precautions for installation
The rule of thumb for pneumatic pipe installation is that the pipe length should be as short as necessary to avoid tight piping. In addition, an excessively large or small diameter of the gas tube and a too small bend radius can result in a reduced flow rate.
The flow rate and bend radius are different for different sizes of support. To ensure proper operation of the system, the proper gas pipe size must be selected according to the specific application and installation requirements.
When bending a PUN-H gas pipe, two key factors should be considered: flow-related bend radius (Rd) and minimum bend radius (Rmin). This difference is very important when designing machines using PUN-H gas pipes. Rmin is related to the structural integrity of the airway, while Rd corresponds to the flow rate supported by the airway.