In food-related fields, the choice of seals is crucial. The correct seal can not only ensure the normal operation of the equipment, but also ensure the health and safety of the food. Because food processing involves high temperatures, pressures, chemicals and frequent cleaning, seals need to have special performance and material requirements. This article will discuss how to choose seals suitable for food-related fields, from material selection, design requirements to certification standards and other aspects of detail.
First, understand the special requirements of food related fields
In food processing and handling equipment, seals need to meet the following special requirements:
Health and safety:
Food contact safety: Seals must meet food safety standards to avoid contamination of food. The materials must meet certification standards such as FDA (US Food and Drug Administration) or EU (European Union).
Non-toxic: The selected sealing material should be non-toxic and harmless to avoid the release of chemicals harmful to food.
High and low temperature resistance:
High temperature tolerance: Food processing often involves high temperature treatment, such as baking, cooking, etc. Seals need to have good high temperature resistance, usually need to be able to withstand high temperatures above 100°C.
Low temperature tolerance: For frozen food processing and storage equipment, seals need to be able to maintain stable performance at low temperatures, usually requiring a low temperature resistance of -30°C or lower.
Corrosion resistance and chemical stability:
Cleaning resistance: Food processing equipment needs to be cleaned and disinfected frequently, and seals need to withstand corrosion from common cleaning agents and disinfectants.
Food additive resistance: seals also need to withstand the erosion of various food additives, seasonings and other chemicals.
Wear resistance and long-term use:
Wear resistance: The long-term operation and high-frequency operation of the equipment will lead to the wear of the seals, so it is necessary to choose a wear resistant sealing material.
Long-term stability: Seals should be able to maintain their sealing performance during long-term use and are not easy to age or fail.
Second, choose the appropriate sealing material
Fluororubber (FKM) :
Advantages: Excellent resistance to high temperatures (typically 150°C to 200°C), corrosion and chemical resistance. Suitable for high temperature and chemical medium environment.
Application: It is often used in food processing equipment that requires high temperature and chemical resistance, such as baking equipment and steam heating systems.
Silicone rubber (SI) :
Advantages: Excellent low temperature resistance (-60°C to +200°C), high temperature stability and food contact safety. Often used in low temperature applications.
Application: Suitable for refrigeration equipment, steam cleaning system and other low-temperature environment sealing requirements.
Nitrile butadiene rubber (NBR)
Advantages: oil resistance and wear resistance is strong, but the high temperature resistance is relatively poor. Suitable for applications requiring oil and wear resistance.
Application: Suitable for food processing in contact with oil or other oily substances equipment.
Polytetrafluoroethylene (PTFE) :
Advantages: Excellent chemical stability, high temperature resistance (typically -200°C to +260°C) and excellent non-adhesion. Suitable for all kinds of chemical environment.
Application: Often used in food processing equipment involving a variety of chemicals and high temperatures, such as chemical additive handling systems.
Polyurethane (PU) :
Advantages: With good wear resistance and elasticity, suitable for applications requiring high elasticity and wear resistance.
Application: Suitable for sealing of frequently moving parts, such as conveyor belts and pump systems in food processing.
3. Select the design requirements of seals
Design size:
Accurate matching: Ensure that the size of the seal is precisely matched to the contact surface of the device to avoid leakage or poor sealing. Especially in high-precision equipment, size matching is particularly important.
Sealing form:
O-ring: Widely used in a variety of static and dynamic sealing scenarios, suitable for most food processing equipment.
V-ring: Suitable for sealing under axial pressure.
U-ring: Suitable for sealing under high pressure and complex environments.
Installation method:
Easy installation: Select seals that are easy to install and remove for easy maintenance and replacement of equipment.
Tightness test: Tightness test is performed after installation to ensure that there are no leaks.
4. Certification standards and supplier selection
Certification standards:
Food contact certification: Select seals that meet FDA, EU or other international food safety standards to ensure their safety.
Quality management certification: Select suppliers with quality management system certification such as ISO9001 to ensure the quality and consistency of seals.
Supplier selection:
Reputation and experience: Choose suppliers with good reputation and rich experience to ensure the provision of high quality seals and excellent after-sales service.
Technical support: Suppliers should be able to provide technical support and advice to help select the most suitable seals.
V. Summary
When selecting seals suitable for food-related fields, it is necessary to consider the food contact safety, high and low temperature resistance, corrosion resistance and long-term stability of the material. Correct material selection and design matching can ensure the sealing performance of the equipment, prevent contamination and leakage, and ensure the health and safety of food processing. By selecting seals that meet certified standards and reliable suppliers, you can effectively improve the operational reliability and production efficiency of your equipment.