Polysulfone is a rigid, high-strength, transparent amber thermoplastic. It maintains its properties over a wide range or temperatures — from -100°F to 300°F, including short temperature bursts to 350°F.
POLYSULFONE AT A GLANCE
- Most costly
- Best for hot water applications
- Good chemical resistance
- Repeat steam sterilization tolerated
- Most difficult to bond
- Continuous service temperature to 275°F
- Light amber color typically
Often used in hot water applications, polysulfone has a high continuous service temperature of 300°F. It is resistant to water absorption and can tolerate steam sterilization up to 285°F. Bio-compatible grades are available in colors.
For manifold design considerations, double-sided full round or single-sided D-channels are possible. Full round channels give the best flow and the least opportunity for unswept volume — however, machining two sides does increase the cost. Typical minimal channel size is .020 (.5 mm) for polysulfone, with channel spacing a preferred 1x apart. Tighter spacing is possible in low-pressure applications.
Unlimited layers are theoretically possible with polysulfone, but costs rise exponentially with layer count. In practice, multiple two-layer manifolds are a smarter choice than a single large, highly complex three-or-more-layer one. Note that, while general performance is higher with polysulfone than with acrylic and polycarbonate, it is more expensive from a raw material perspective. Bond line threads are acceptable. Staked-in threaded inserts are recommended over helicoils when using polysulfone, so as to avoid stress-cracking concerns.
More about Polysulfone
Polished polysulfone parts are light amber in color. Vapor polishing and optical machining are effective methods for clarity. Polished polysulfone components can achieve surface finishes of under 1 micro inch with optical machining. Polysulfone parts are particularly resistant to radiation sterilization, and a common application for clear polished polysulfone is sterilization trays. This material’s clarity allows for easy top-down inspection. Clear polysulfone components can be used in FDA-compliant devices.
Polysulfone's General Engineering Characteristics
- Tensile strength at yield: 10,200 psi
- Modulus of elasticity: 360,000 psi (tensile), 390,000 psi (flexural)
- Dielectric strength: 425 v/mil
- Continuous service temperature in air: 300oF, with bursts to 340°F
- Low creep under continuous load at elevated temperatures
- Chemical resistance to mineral acids, alkali, salt solutions, detergents, and hydrocarbon oils
- Resistant to hydrolysis
- Can be repeatedly steam and dry-heat sterilized
Note: When building polysulfone products, use threaded inserts only when frequent assembly/disassembly is expected. Directly threaded polysulfone fluidic manifolds will perform acceptably for single-assembly applications (if torque limits are not exceeded at time of install).