PTFE Diaphragms for Food Grade Pumps
The food industry is continually challenged by a variety of issues in the processing of organic raw materials, with hygiene being at the top of the list. Pumping delicate slurries and media containing large solids are common problems. These must be faced at various stages of the food processing cycle. The possibility of the media shearing or splitting, and its potential to adhere to the internal surfaces will always be considerations.
The Importance of Diaphragms in Pumps for Food Processing
For companies using air operated diaphragm pumps or metering/dosing pumps, it is essential the diaphragms are compatible with all relevant industry standards. Any break-up of the diaphragm surface has the potential for cross-contamination of the pumped media. The pump diaphragms therefore need to be ultra-smooth to ensure a smooth flow, crevice-free to avoid any solids becoming trapped and not prone to cracking. For food and beverage industry pumps, it is also crucial that they are suitable for liquids used.
Strict adherence to cleaning-in-place (CIP) and sterilization-in-place (SIP) standards is essential in food processing. Saint-Gobain's food grade pumps offer high thermal and chemical resistance to acidic and alkaline CIP cleaning media. Diaphragm systems can be disinfected and cleaned without disassembly decreasing downtime and maintenance.
Use of Food Grade Plastic Valves and Diaphragms
A solution to these challenges can be met by diaphragms engineered from the highest quality Polytetrafluoroethylene (PTFE) resins. PTFE diaphragms made of Saint-Gobain’s CHEMFILM® products have almost universal chemical resistance and extremely low moisture absorption characteristics (<0.01%).
Due to its thermal resistance, this type of plastic valves and diaphragms work in continuous use temperatures of 260°C (500°F), making them a perfect choice for pumps for high temperature food applications. This means processing up to as many as 20,000 service hours with little to no mechanical function loss at elevated temperatures.
Used either on its own, or as part rubber backed diaphragms, CHEMFILM® Flex Barriers from Saint-Gobain provide exceptional barrier properties for diaphragms, enabling them to withstand a million to ten million of flex cycles.
Hygiene Requirements for Pump Diaphragms
Contamination attributable to a diaphragm’s rough surface has been eliminated by the smooth inert surface of the barrier. And for deep drawing manufacturing issues, where the problem’s root cause is stiff and heterogeneous material, the high quality and flexibility of these barrier films removes causes for concern. This ensures best hygiene and lowers the cost of maintenance.
Specifically, for pumps for food processing, it is crucial that materials coming in contact with food comply with industry regulations. Purest PTFE resins, used for Saint-Gobain Flex Barrier materials used in diaphragms and valves, comply with the following regulations:
• FDA 21 CFR 177.1550
• (EC) No 1935/2004
• (EU) No 10/2011
• (EC) No 23/2006 (GMP)
• USP Class VI
• 3-A Sanitary Standard
Material Selection Guide for Food Grade PTFE Diaphragms
|Material||Product Code||Thickness, mm||Key Features||Optional Features|
|PTFE Skived Film Premium||0100||0.025 - 3.0||Universal -- great bending fatigue strength||Customization available|
|PTFE Skived Film Modified||0200||0.025 - 3.0||Excellent elongation at break||Customization available|
|PTFE Skived PTFE Film Flex Barrier||LP01
0.4 - 1.0
|Developed to provide outstanding flex life in pump applications||Customization available|
For all our materials, we offer customization options tailored to suit your needs. Please Contact Us to discuss your requirements or to request a call back from one of our pump diaphragms technical experts.