In 1931, a pair of German scientists invented a nitrile rubber compound that combined natural rubber with man-made additives. This material would come to be known as Buna-N. Over time, Buna-N became a popular choice in industrial sealing applications. Later, air-operated double-diaphragm (AODD) pump manufacturers found great success using Buna-N for the pump’s diaphragms because it offered better abrasion, tear, water and oil resistance, and decent flex compared to other materials. However, in 1954, an improved compound called thermoplastic elastomer (TPE) was introduced to the industrial market.
Thermoplastic elastomers – a physical mix of polymers that consist of materials with both thermoplastic and elastomeric properties – provide a more durable and adaptable material option for pump diaphragms. One of the more resilient materials composed of TPE is Saniflex™(Hytrel®), which is much stronger than synthetic rubber and withstands greater temperature ranges than Buna–N (Figure 1).
Saniflex combines the flexibility of rubber and the strength of thermoplastics, which gives it abrasion, heat and chemical resistance, along with greater durability and improved flex life. Given these operational benefits, Saniflex is an ideal option for sanitary applications. However, the strength and versatility of Saniflex is also suited for a wide range of other industrial applications, especially when paired with the Wilden Chem-Fuse Integral Piston Diaphragm design.
Ending The Diaphragm Dilemma
Wilden Chem-Fuse Integral Piston Diaphragms, which are manufactured with the more advanced TPE compound in the form of Saniflex (Hytrel), are becoming the new standard for AODD pump diaphragms because it outperforms Buna-N in industrial applications in terms of abrasion resistance, leak prevention and overall durability.
The resistance power of Saniflex is only complemented by the Integral Piston Diaphragm (IPD) design of Chem-Fuse diaphragm that encases the shaft connection within the diaphragm material. This design eliminates the well-known wear and product-trap areas that are inherent in traditional diaphragms. The design of Chem-Fuse diaphragm also eliminates abrasive wear on the outer piston during operation. The combination of the Chem-Fuse design, along with the durability and resistance capabilities of Saniflex, creates a safe and leak-free diaphragm, which is a critical need for applications that handle a range of dangerous or hazardous non-food-grade oils, abrasives and solvents.
Chem-Fuse Integral Piston Diaphragms manufactured with Saniflex – currently available for use on Wilden 25 mm (1”), 38 mm (1.5”), 51 mm (2”) and 76 mm (3”) Pro-Flo® SHIFT and Pro-Flo® metal and plastic pump models – provide the highest level of durability, reliability and safety, even when used in the most challenging industrial pumping conditions.
To learn more about how Wilden Chem-Fuse Integral Piston Diaphragms in Saniflex (Hytrel) outperform Buna, read the white paper: Saniflex™ (Hytrel®) Diaphragms in place of Buna in Industrial Applications.