Gaskets and seals used in food production processes and equipment have to meet strict requirements for purity. In addition, food-grade gaskets and seals must service challenging process conditions, while resisting attack and degradation from chemicals and other substances with which they may come into contact. Due to the nature of food applications, a key challenge is selecting the right sealing material for the job.
Gaskets and Seals for Food Applications: Key Challenges
In selecting an appropriate for sealing material for a food application, the following considerations are key:
Consumer health and safety. To ensure consumer health and safety, sealing materials will have to comply with strict regulations and standards. Materials which have been tested and proven to comply with specific regulations and standards will be certified as compliant. For example, sealing materials designed to support potable (drinking) water applications, are certified as compliant to the NSF/ANSI 61 standard.
Neutrality and stability. Gaskets and seals used in food applications should not introduce any unwanted odours or taste into ingredients or products with which they might come into contact. In addition, such gaskets and seals should be stable and not release any unwanted contaminants or parts which could find their way into the product stream.
Process conditions. Gaskets and seals for food applications must service challenging process conditions. These include wide temperature and pressure service ranges, aggressive media, high mechanical loads, and cleanability. Cleanability is often overlooked as a key material challenge: sealing materials used in food applications are often installed on equipment which must be cleaned frequently with chemical disinfectants and superheated steam. The sealing material chosen should be capable of supporting the required cleaning regimen.
Gaskets and Seals for Food Applications: Material Guide
Selecting gaskets and seals for food applications can involve examining a wide range of materials. The following list highlights materials that CRG often uses to produce gaskets and seals for food applications. For guidance on selecting a material suitable for your specific application, please contact CRG directly.
Perfluoroelastomer (Kalrez®). Kalrez® is a DuPont perfluoroelastomer (FFKM). Gaskets and seals from Kalrez® resist over 1,800 different chemicals, while offering the high temperature service (327°C) and stability of PTFE. Kalrez® gaskets and seals provide low outgassing in vacuum-sealing applications. FDA-compliant seals are also available for food applications.
Fluorosilicone gaskets are often used in food applications. CRG supplies gaskets cut from fluorosilicone-formulated kSil™ and NeutraSil™ sheet. kSil™ silicone sheet is FDA approved and food manufacturers can be confident that gaskets fabricated from kSil™ are safe should they come into contact with the product stream during processing. In addition to kSil™ sheet, CRG also fabricate silicone gaskets from neutraSil™ sheet. NeutraSil™ is an antimicrobial silicone rubber that has been independently proven to prevent the growth of E-Coli, MRSA and Salmonella bacteria. The antimicrobial qualities of neutraSil™ make it highly suited to end-use applications in food and beverage production.
PTFE. PTFE gaskets and seals are often used in food mixers, pumps, valves, and flanged joints in piping and transfer equipment. These gaskets combine excellent dielectric properties with a very low coefficient of friction and an ability to service a wide range of operating temperatures, from -240°C (-400°F) to 260°C (500°F). A key advantage of PTFE gasket material is that is among the most chemically resistant materials known. The ability to resist chemical attack makes PTFE sheet a material of choice for many sealing applications in the food industry.
EPDM and Nitrile (NBR). CRG uses these materials to produce gaskets which service many standard food-grade applications.
NSF/ANSI 61 EPDM. CRG supplies gaskets and seals made from EPDM material certified as compliant to the NSF/ANSI 61 standard. These gaskets support food and beverage applications where the use of gaskets compliant to the NSF/ANSI 61 standard is required.
Food-grade pump packing. CRG supplies Teadit style 2005 pump packing which meets the requirements of FDA and USDA requirements under Title 21 Food and Drugs: Part 177.1500 – Perflourocarbon Resins; and Part 178.3570 – Lubricants with Incidental Food Contact. Manufactured using an advanced method of braiding and construction, Teadit style 2005 is a premium food-grade pump packing that offers excellent performance in service. It is especially well-suited for food applications involving sugar and alcohol. Style 2005 provides an FDA-compliant PTFE compression packing seal that protects rotating pumps and valves from fluid leaks – a vital consideration in food processing applications.
CRG can produce gaskets and seals for food applications from the above materials, as well as others that we have in our material portfolio. Our sales specialists will be pleased to review your application and provide guidance on selecting the most appropriate material. All gaskets and seals CRG produces are custom fabricated using the latest CNC production equipment in our ISO 9001-certified facility.
To find out more about CRG gaskets and seals for food applications, please contact our sales team at crg@canadarubbergroup.com.