Elastomers
- October 09, 2019
Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Website and was written by Fred Fisher, technical sales engineer of the Engineered Materials Group.
You just spent 6 months testing, stretching, aging and exposing your new seal design to 12 different chemicals. Finally, you are done. So what does a good technical drawing for a seal include? For most companies, the drawing is simple. For an O-ring,
- October 01, 2019
Jay Berwanger, Heisman Winner.
To football aficionados, Jay Berwanger is well-known as the winner of the first Heisman Trophy and the first player chosen during the National Football League’s first draft. Less well-known is that he achieved his athletic successes at the University of Chicago, a school now more closely associated with Nobel prizes than big-time football. Berwanger, a halfback, played for the University of Chicago Maroons at a time when Chicago was a member of the Big Ten Conference–before Robert Hutchins, the University’s president, famously abolished varsity football in 1939.
Even in an era before football teams were divided up into offensive and defensive squads, Berwanger was renowned for his versatility.
In 23 varsity games in three seasons
- September 05, 2019
Tensile Strength | Ultimate Elongation | Modulus of Elasticity
Rubber Compound Data sheets usually display a number of physical properties as recorded from standard test methods. Among the most common are three measured on the Tensometer:
- Tensile Strength (at break)
- Ultimate Elongation
- Modulus of Elasticity
The Test
The Tensometer stretches a specimen, or dumbbell, cut from a sheet of rubber, until it breaks. During the test, the force required and length of the gauged section are measured continuously. These measurements are used to calculate the various results, which considers the actual dimensions of the test specimen.
While Tensile Strength and Ultimate
- August 13, 2019
Seals do their jobs tirelessly, usually behind the scenes. Until now, machines mostly had to be dismantled to check the condition of these parts. That’s expected to change: At Freudenberg Sealing Technologies, a cross-disciplinary team is testing seals that identify and communicate their level of wear. They are based on a novel material that functions as a sensor.
It’s time for maintenance at a beverage bottling facility. Different components of the equipment are opened up, and the seals on tubes, pumps and valves are checked. If they are worn out, they have to be replaced. But if they are still intact, the check itself – a common yet expensive process – is superfluous. What would happen if the seals themselves could autonomously measure and transmit information about the level of their wear? And determine the exact point – no sooner and no later – when little of the seal lip is left and the seal has to be replaced? The future of seals may lie
- August 06, 2019
Rubber seals are used in numerous industries to prevent the unwanted leakage of liquids and gases in various components such as pumps, valves, pipe fittings, and vacuum seals, to name only a few. However, all seals are not created equally. Rubber seal design consists of several elements to ensure that the seal delivers optimal performance in the given environment.
One of the most common types of industrial rubber seals, the O-ring, relies on mechanical compressive deformation to act as a barrier between mating surfaces, thus restricting the flow of fluid in predetermined areas. Several factors must, therefore, be taken into account in O-ring seal design to sustain the compressive force and maintain an effective seal.
Key Design Considerations
Rubber seals are available in a large number of material compositions, each with its own set of advantages and limitations. The selection of the appropriate material involves the consideration of specific factors including:
- July 23, 2019
Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Website and was written by members of the O-Ring & Engineered Seals Division. Jacob Ballard - research and development engineer, Jason Fairbanks - market manager, and Nathaniel Sowder - business development engineer.
- June 13, 2019
Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Website and was written by Dorothy Kern, applications engineering manager for the Parker O-Ring & Engineered Seals Division.
Perhaps you know Parker’s newest EPDM material is EM163-80. Featuring breakthrough low temperature functionality, resistance to all commercially available phosphate ester fluids, and the ability to be made into custom shapes, extrusions, and spliced geometries, EM163-80 represents the best-in-class material for applications needing to seal
- May 14, 2019
Seals are one of the most important components in many medical devices. While small in cost, seals for medical devices have a profound affect on the function of said device and the outcome of a medical procedure.
Engineered sealing solutions have advanced to meet the new medical device designs due both to new materials and to new processes for producing these seals. An understanding of the fundamentals of seal design, the tools available to assist in the manufacturing process and pitfalls to avoid will help in achieving a successful seal and medical device outcome.
Classifying the three basic seal designs
When approaching a new seal design, It is important to classify the seal based on its intended function. All seals fall into one of three distinct groups. While certain applications may combine more than one group, there is always one that is dominant. The three basic seal designs are:
Static -- seal applications where there is no movement.
Reciprocating -- seal applications where there is linear motion.
Rotary -- seal applications where there is rotation.
Static seal applications are the most common and include those that prevent fluids and drugs from escaping into or out of a medical device. The seal design can range from basic O-rings to complex shapes. Static seals can be found in the broadest range of medical devices from pumps and blood separators to oxygen concentrators.A reciprocating seal application with linear motion would include endoscopes that require trocar seals. These trocar seals are complex in design and allow the surgeon to insert and manipulate instruments to accomplish the medical procedure. These procedures range from relatively simple hernia repairs to the most difficult cardiac procedures. All of these minimally invasive surgeries employ endoscopes with seals that rely on seal stretch, durability and ability to retain shape during lengthy and arduous procedures. This particular seal application combines both reciprocating and rotary motion with the main function being linear motion.
A rotary seal application most commonly includes O-rings used to seal rotating shafts with the turning shaft passing through the inside dimension of the O-ring. Systems utilizing motors such as various types of scanning systems require rotary seals but there are many other non-motorized applications that also require rotary seals. The most important consideration in designing a rotary seal is the frictional heat buildup, with stretch, squeeze and application temperature limits also important.
Function of a particular seal design
What is the function of the seal? It is important to identify specifically if the design must seal a fluid and be impermeable to a particular fluid. Or will the seal transmit a fluid or gas, transmit energy, absorb energy and/or provide structural support of other components in device assembly. All of these factors and combinations need to be thoroughly examined and understood to arrive at successful seal design.
A seal's operating environment
In what environment will a seal operate? Water, chemicals and solvents can cause shrinkage and deformation of a seal. It is important therefore to identify the short and long term effects of all environmental factors including oxygen, ozone, sunlight and alternating effects of wet/dry situations. Equally important are the effects of constant pressure or changing pressure cycle and dynamic stress causing potential seal deformation.
There are temperature limits in which a seal will function properly. Depending on the seal material and design, a rotary shaft seal generally would be limited to an operating temperature range between -30° F and +225°F. To further generalize, the ideal operating temperature for most seals is at room temperature.
Expected seal life - How long must the seal perform correctly?
- April 18, 2019
The popularity of multi-flavor drink dispensers, those touch screen wonders that offer dozens of beverage and flavor options to consumers, has grown during the past decade. Manufacturers are installing these complex machines in venues and locations throughout the world.
Elastomers and flavor transfer
But what’s great for an individual customer – a cherry-ginger-lime cream soda, for example – can play havoc with the elastomer seals inside the machine. Add in hygienic cleaning requirements and proper food contact certifications and equipment manufacturers can find themselves spending months chasing challenges like flavor transfer, leaks and material compliance approvals.
Freudenberg-NOK Sealing Technologies, a leading specialist in advanced sealing applications, has a portfolio of solutions to resolve these issues. The company, which runs the business operations for Freudenberg
- February 12, 2019
Replacing Aging Water Infrastructure With NSF Compliant Materials
There are over 155,000 public water systems in the United States and more than 286 million Americans who rely on community water systems daily. Since most of the infrastructure was built between the early 1900's and 1960 using outdated technology/products and capabilities, nearly everything is approaching the natural end of it's lifespan.
Some estimates put the repairs and replacement of the infrastructure between $250B and $500B over the next 20-30 years. Several applications will need to be updated or fully replaced for the safety of consumers and quality of delivery, including:
- Joining and sealing materials
- Mechanical devices
- Pipes or related products