HNBR is a highly saturated elastomer produced by special hydrogenation of nitrile butadiene rubber (NBR). Since its creation in the 1930’s, the petroleum-based synthetic rubber, NBR has long been the standard for general purpose, low cost and low heat applications while FKM (fluorcarbon)has been the choice for higher heat.
In the 1980’s, HNBR was introduced as an alternative between NBR and FKM (fluorcarbon). While NBR is inexpensive, it only has a temp range of -30°F to +250°F. FKM has a higher temp range,15°F to +400°F, but it can be cost prohibitive. HNBR offers a compromise between the two with a temp range of -20°F to +302°F. It also offers a higher tensile strength, higher operating temperatures, and excellent resistance to chemicals and ozone. Since its development, HNBR has been polymer of choice in air conditioning systems and many other sealing applications.
Before choosing which compound may work best for your application, don’t forget the role that the fluid, operating temperature,and pressure play in a healthy operating environment. We’ve made a list of the pro’s and con’s of HNBR below.
HNBR Advantages
Wide Temperature range
Abrasion resistance
Resistance to weather, ozone, fuels, oils, sour gas, steam, fats, automotive fluids, and extended service life
Typically green in color or easy identification
Available in both o-rings or various hydraulic cylinder packings
HNBR Disadvantages
Higher Cost
Limited resistance to aromatic oils and polar organic solvents
Poor electrical properities and poor flame resistance
Custom machined seals are a great sealing option when product isn’t available, cylinders have been modified, or when prototypes are needed, (without the expense and leadtime of tooling). There hundreds of profiles and materials available, made on demand with some lead times as quick as the next day.
Our sales staff will work with you to determine the profiles and materials best suited for your application. We will also work with our partners to engineer new sealing solutions. We’ve added a quick custom seal form to help you with your specialty seal selection. Just remember, when dealing with custom seals, S.T.A.M.P.S.S.
S-Size of current housing, groove dimensions
T-Temperature (operating) of system
A-Application where the system is to be used
M-Media/fluid to be sealed
P-Pressure
S-Speed system cycles
S-Surface finish of rod and/or bore
Rubber seals play a crucial role in various industries, providing effective sealing solutions for applications ranging from automotive and aerospace to construction and manufacturing. As sealing technologies continue to advance, the future of rubber seals holds several exciting trends and advancements and Pneu-Draulics will be there every step of the way.
Below are some key areas:
The rise of the Internet of Things (IoT) and smart manufacturing has opened doors for intelligent rubber seals. These seals can incorporate sensors and actuators to monitor and control parameters like pressure, temperature, and wear. Smart seals enable real-time monitoring, predictive maintenance, and improved efficiency by providing data-driven insights into seal performance and potential failures.
Self-healing materials are gaining attention in the field of rubber seals. Researchers are exploring the integration of microcapsules or reversible bonds within the seal material to enable automatic repair of small cracks or damages. Self-healing seals have the potential to significantly increase the lifespan and reliability of seals in demanding environments.
Sustainability is a growing concern, and the future of rubber seals includes a focus on eco-friendly alternatives. Manufacturers are exploring bio-based rubber seal materials derived from renewable sources. Additionally, recycling and waste reduction efforts are being implemented to minimize the environmental impact of seal production and disposal.
The adoption of additive manufacturing, particularly 3D printing, is revolutionizing the production of rubber seals. This technology allows for complex geometries and customization, reducing lead times and costs. 3D printing enables the creation of seals with optimized designs, tailored to specific applications, resulting in improved sealing performance.
Computer-aided design (CAD) and simulation tools are becoming increasingly sophisticated, enabling engineers to optimize seal designs for better performance. Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) simulations help predict seal behavior, improve sealing efficiency, and reduce leakage. Virtual prototyping and testing reduce the need for physical iterations, saving time and resources.
Surface treatments and coatings are being developed to enhance the performance of rubber seals. These technologies aim to improve properties such as friction, wear resistance, and chemical resistance. Nano-coatings and low-friction surface modifications are being explored to minimize seal friction and extend service life.
Industries such as oil and gas, aerospace, and high-performance automotive applications require seals that can withstand extreme conditions. Future advancements will focus on developing seals capable of withstanding high temperatures, high pressures, corrosive environments, and harsh chemicals, ensuring optimal performance and safety in demanding applications.
The future of rubber seals holds great potential for advancements that will enhance their performance, durability, and sustainability. These innovations will contribute to increased efficiency, reduced maintenance costs, and improved reliability in various industries, supporting technological progress and addressing evolving challenges.
O-rings are essential components used for sealing applications in various industries. Understanding key terminology related to durometer and Shore hardness is crucial when selecting the correct O-ring material. In this article, we will delve into the meaning of these terms and their significance in relation to FKM (fluorocarbon rubber), urethane, and NBR (nitrile butadiene rubber) materials.
Durometer is a measure of the hardness of an elastomer material, such as rubber. Shore hardness is the most commonly used durometer scale, developed by Albert F. Shore. It quantifies the hardness by measuring the resistance to indentation. The Shore hardness scale consists of different scales, including Shore A, Shore B, and Shore D.
Shore A durometer measures the hardness of relatively soft elastomers, particularly rubber materials. It has a scale ranging from 0 to 100, where higher values indicate a harder material. O-rings made from materials like NBR are typically measured using Shore A durometer. For instance, a Shore A durometer reading of 70 indicates a relatively hard material.
Shore B durometer is used to measure the hardness of elastomers that are slightly harder than those measured with Shore A durometer. It also has a scale from 0 to 100, with higher values representing increased hardness. However, Shore B durometer is less commonly used for O-rings, as materials like FKM and NBR generally fall within the Shore A measurement range.
Shore D durometer measures the hardness of rigid materials, including hard rubbers, plastics, and thermoplastic elastomers. It has a scale ranging from 0 to 100, where higher values indicate greater hardness. Although Shore D durometer is not typically used for O-rings, it can be relevant when evaluating materials like urethane, which can have higher hardness compared to traditional elastomers.
Understanding durometer and Shore hardness scales is crucial when selecting the right O-ring material for specific applications. Shore A durometer is commonly used for measuring the hardness of FKM and NBR O-rings, while Shore B and Shore D durometers are more relevant for harder materials like urethane. By considering the appropriate hardness for each material, businesses can ensure the selection of O-rings that offer optimal sealing performance, durability, and resistance to specific operating conditions.
Per- and polyfluoroalkyl substances (PFAs) are an ever-present part of our lives, from our cookware to our clothing and, notably, the sealing industry. However, these man-made chemicals have been the focus of increasing scrutiny. What is the future of PFAs and how will it shape the sealing industry?
PFAs are synthetic chemicals known for their ability to resist heat, water, and oil. This has made them incredibly useful in various industries, including the manufacture of gaskets, seals, and O-rings.
However, PFAs have been labeled “forever chemicals” due to their persistence in the environment and in our bodies, leading to potential health risks. As more research uncovers these impacts, the future of PFAs looks increasingly uncertain.
In the past, the sealing industry has been a significant user of PFAs due to their unique properties. PFAs provide exceptional performance in high-temperature applications and in environments exposed to aggressive chemicals. But with potential regulatory changes on the horizon, the industry is faced with an impending challenge. How do we maintain high-performance sealing solutions without relying on PFAs?
A possible alternative is the use of perfluoroelastomers (FFKMs), which maintain many of the desirable properties of PFAs but have a different chemical structure that may pose less environmental and health risk.
The development of greener manufacturing processes and materials also holds promise for creating PFAs-free seals and gaskets. These new materials must meet the rigorous demands of the industries served, a challenge that the sealing industry is determined to meet.
The future of PFAs presents a complex challenge for the sealing industry. However, as regulatory pressures mount, the industry is showing it’s ready to innovate, seeking out alternatives that deliver the same high performance without the environmental and health impact. This is an exciting time in the industry, a time of change and innovation. The sealing industry may soon unveil new materials that revolutionize the way we think about high-performance seals.
Sources:
Per- and Polyfluoroalkyl Substances and Your Health
Sealing Technology, “The Impact of PFAs on Sealing”
Revolutionizing High-Temperature Stability and Chemical Resistance
In today’s fast-paced and demanding industrial landscape, engineers and manufacturers are constantly seeking advanced materials that can withstand extreme conditions while delivering reliable performance. Parker Hannifin has introduced their newest FFKM compound FF156, which offers exceptional high-temperature stability and broad chemical resistance. The remarkable features and applications of Parker’s FF156 compound shows its value and why it will become the preferred choice of engineers in critical environment industries.
One of the standout features of compound FF156 is its extraordinary high-temperature stability. Capable of withstanding temperatures of up to 527°F/275°C, FF156 ensures reliable sealing even in the most demanding applications. This exceptional heat resistance makes it suitable for use in environments such as high-temperature reactors, downhole drilling systems, exhaust and turbo systems, and steam applications. Engineers can have peace of mind knowing that their equipment can operate efficiently at elevated temperatures without compromising on sealing integrity.
In addition to its impressive high-temperature capabilities, FF156 also boasts broad chemical resistance. It exhibits exceptional resistance to aggressive media, including acids, amines, hot water, ketones, aldehydes, esters, ethers, aromatics, and many more. This versatility enables FF156 to thrive in chemically demanding environments, making it ideal for applications in the chemical processing, oil and gas, and pharmaceutical industries. Furthermore, FF156 has received USP Class VI approval, ensuring its compliance with the strict regulatory standards required in medical and pharmaceutical applications.
FF156 FFKM is available in a range of geometries, including O-rings, molded shapes, extruded profiles, and spliced configurations. This versatility allows engineers to choose the most suitable form for their specific application requirements. Whether it’s mechanical seals, pumps, valves, instrumentation equipment, high purity filters, or any other critical component, FF156 delivers outstanding sealing performance across various industries.
Parker Hannifin’s O-Ring and Engineered Seals Division has gained the reputation of being the preferred choice of engineers in critical environment industries. Aerospace, oil and gas, and chemical processing are just a few of the sectors that rely on Parker’s expertise and products to ensure the safe and reliable operation of their equipment.
You can trust Pneu-Draulics with our extensive experience, commitment to innovation, and exceptional customer support, to guide you every step of the way when determining the best material and profile for your application.
When it comes to rubber and urethane seals, understanding their shelf life is essential to ensure optimal performance and reliability. Seals are commonly used in various industries, including automotive, manufacturing, and engineering. Knowing how long these seals can be stored before their properties begin to degrade is crucial for maintaining their effectiveness.
Understanding Rubber Seals
Rubber seals, commonly made from materials such as neoprene, nitrile, or silicone, are widely used for their flexibility, resistance to temperature extremes, and durability. However, rubber seals are not invincible and can deteriorate over time when not stored or used correctly.
The shelf life of rubber seals can vary depending on several factors.
Rubber seals should be stored in a cool, dry environment away from direct sunlight, chemicals, ozone, and extreme temperatures. Exposure to these elements can accelerate the aging process and lead to premature deterioration.
Different types of rubber have varying resistance to environmental factors. It’s important to consult the manufacturer’s guidelines to determine the expected shelf life of a specific rubber seal material.
The quality and formulation of the rubber material used in the seals can impact their overall shelf life. Higher-quality seals are often designed to last longer and maintain their properties for an extended period.
Understanding Urethane Seals
Urethane seals, also known as polyurethane seals, are valued for their excellent wear resistance, high load-bearing capabilities, and resistance to oil and solvents. They are commonly used in hydraulic systems, pneumatic applications, and heavy machinery.
The shelf life of urethane seals can also be influenced by various factors:
Similar to rubber seals, urethane seals should be stored in a controlled environment with low humidity and moderate temperatures. Exposure to excessive moisture and heat can degrade their properties.
The formulation of the urethane material, including additives and fillers, can affect its resistance to environmental factors and determine its expected shelf life.
It is crucial to follow the manufacturer’s guidelines for the storage and handling of urethane seals. They may provide specific instructions or recommendations for prolonging the shelf life of their products.
Inspecting and Replacing Seals
Regardless of the type of seal, it’s important to regularly inspect them for signs of deterioration or damage, even if they are within their expected shelf life. Common indicators of seal degradation include cracks, hardening, swelling, or a loss of elasticity. If any of these signs are present, it is advisable to replace the seals to prevent potential failures and maintain system integrity.
The shelf life of rubber and urethane seals can vary depending on storage conditions, seal type, and material quality. Proper storage in controlled environments and adherence to manufacturer’s recommendations are essential for prolonging the lifespan of these seals. Regular inspections and proactive replacement when signs of degradation are detected will help ensure the optimal performance and reliability of the seals in various industrial applications.
The evolution of hydraulic and pneumatic seals is a testament to human ingenuity and our relentless pursuit of efficiency and power. From the remarkable aqueducts of the Roman Empire to the cutting-edge technology of the modern era, the development of sealing systems has significantly shaped our ability to harness fluid power. The ingenuity of the Romans laid the foundation for hydraulic engineering, demonstrating the importance of seals in maintaining fluid integrity. The seals used in the aqueducts to prevent leaks and maintain water pressure were often made of clay, plaster, and sometimes animal fat.
As Europe entered the Middle Ages, windmills became a crucial source of power for milling grain and pumping water. The seals used in these early machines were often leather or simple fabric, designed to reduce friction and prevent fluid leakage. This period marked a transition from hydraulics to pneumatics, as windmills harnessed the power of moving air. While elementary compared to modern standards, these seals represented a significant advancement in sealing technology.
The 18th and 19th centuries ushered in the Industrial Revolution, transforming manufacturing and transportation. Steam engines emerged as a dominant force, and with them, the need for improved sealing solutions. During this era, the discovery and widespread use of rubber marked a milestone in sealing technology. Natural rubber seals found their way into steam engines, enabling them to operate efficiently and safely. This innovation not only revolutionized industry but also paved the way for further advancements in sealing materials. The early 20th century witnessed the development of synthetic rubber compounds, such as neoprene and nitrile, which offered superior resistance to temperature extremes, chemicals, and wear. These materials became the foundation for modern hydraulic and pneumatic seals.
Standardization also gained prominence during this era, which led to interchangeable seal sizes and specifications, simplifying maintenance and repair processes across industries. Today hydraulic and pneumatic seals have reached unprecedented levels of precision and performance. Engineers have access to a wide array of materials enabling them to design seals with exceptional sealing capabilities and extended service life.
Computer-aided design (CAD) and finite element analysis (FEA) have revolutionized seal design, allowing engineers to optimize seal geometry for specific applications. This precision engineering has led to increased efficiency, reliability, and durability.
As we look ahead, the quest for enhanced performance, sustainability, and efficiency continues to drive innovation in sealing technology. Advanced materials, digital design tools, and an unwavering commitment to progress ensure that hydraulic and pneumatic seals will remain at the forefront of engineering advancements, enabling us to harness the power of fluids for generations to come.
Sources:
Hodge, A. Trevor. “Roman Aqueducts and Water Supply.” Bristol Classical Press, 2002.
Adamson, John. “Windmills.” Oxford University Press, 1981.
Croft, Terrell. “Steam Engine Principles and Practice.” McGraw-Hill, 1929.
Wilkes, James A. “The Properties of Rubber.” Clarendon Press, 1966.
O’Brien, Robert J. “Handbook of Pneumatic Conveying Engineering.” CRC Press, 2003
