Fluidics, the science of controlling and manipulating fluid flow, relies on precision-engineered components to perform efficiently. Plastic materials play a critical role among these components due to their versatility, manufacturability, and performance characteristics. Selecting the right plastic for fluidics applications involves more than just understanding its mechanical properties; it requires a deep dive into its chemical compatibility, durability, and machinability or moldability. Engineers must evaluate environmental and material compatibility to ensure seamless operation.
Material Requirements for Fluidics Applications
Fluidics systems often handle a variety of substances—from water to corrosive chemicals and even biological fluids. This diverse range of fluids means the materials used must exhibit key characteristics to ensure the reliability and longevity of the plastic components. Depending on the application, the material must offer chemical resistance, dimensional stability, tolerance to extreme temperatures, low coefficient of friction, and, in cases where fluid monitoring may be necessary, transparency or optical clarity.
Finding the right material requires an understanding of the application and what it may encounter environmentally or as part of its functionality. Using a plastic that reacts with the fluid can compromise both the component and the fluid. A poorly chosen material may swell, crack, or degrade over time. However, selecting materials involves more than fluid compatibility.
A material unable to withstand operating temperatures may deform or lose its mechanical integrity, leading to leaks or component failure. In dynamic systems, materials with inadequate wear resistance can lead to premature failure, requiring costly replacements or repairs. Additionally, external environments, such as exposure to UV rays, seawater, or extreme weather conditions, can degrade certain plastics. Finally, compatibility with adjacent materials is crucial; some plastics might react negatively when in prolonged contact with other materials in the system, leading to corrosion, stress cracking, or chemical leaching.
Commonly Used Plastics in Fluidics
As previously stated, making an appropriate material choice requires matching the application needs with the material properties. Below are some plastics that are used in fluidic system components.
Polycarbonate (PC) is a versatile plastic that provides transparency, impact resistance, and moderate chemical resistance, making it a go-to material for fluid monitoring systems. Different grades of polycarbonate have varying chemical resistance levels, so choosing the right grade is crucial based on the specific fluids the part will encounter.
Polyphenylene Sulfide (PPS) is an engineered thermoplastic with high-temperature resistance—long-term resistance up to 200°C (392°F) and short-term resistance up to 260°C (500°F). It also offers chemical resistance, flowability, and dimensional stability—even in many harsh chemical environments. Its dimensional stability allows for the molding of complex parts with tight tolerances. However, the specific fluid compatibility must be carefully considered based on the chosen PPS grade and the specific fluid involved.
Polyvinylidene Fluoride (PVDF) can withstand exposure to a wide range of aggressive liquids and solvents without degradation. Its smooth surface minimizes fluid adhesion, promoting efficient flow within the fluidic system. PVDF maintains its shape even when exposed to varying temperatures and pressures, ensuring consistent performance in fluidic systems.
Acrylonitrile butadiene styrene (ABS) combines the hardness and heat resistance of acrylonitrile with the impact toughness of butadiene and the processability of styrene, making it suitable for a wide range of fluidic applications where both strength and flexibility are needed. While ABS is generally considered chemically resistant, it’s important to check compatibility with specific fluids as certain chemicals can degrade the material. Additionally, ABS has a moderate temperature range, so it’s important to consider the operating temperature of the fluidic system.
Polypropylene (PP) is a relatively inexpensive plastic, making it a cost-efficient option for many fluidic applications. It is commonly used for general-purpose applications. PP exhibits good resistance to most acids, bases, alcohols, and organic solvents and can withstand moderate temperatures.
Plastic materials are the backbone of modern fluidic systems, offering the versatility and performance required for diverse industries. By understanding the characteristics and limitations of various plastics, engineers can design components that meet stringent performance criteria while avoiding costly failures. Whether injection-molded or machined, the right material selection ensures that fluidic systems operate efficiently and reliably, even in the most demanding environments.
Ensinger is Your Strategic Partner for Fluidic Components
Do you have fluidic components with complex geometries and critical tolerances? Through injection molding and/ or CNC machining, we can produce precision parts for fluidic systems in any industry. We have the skills and experience to meet your most demanding challenges head-on while helping you overcome cost concerns, design issues, and long lead times. Through a design for manufacturability (DFM) review, we will evaluate the part’s materials and design for cost-effectiveness while ensuring it can withstand the rigors of use. We are well-positioned to take on your challenges and deliver what you need when you need it. Contact us to get started on your next project.