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Clik here to view.The O-Ring & Engineered Seals Division is now offering a rapid prototype program for solid and hollow spliced O-rings that will reduce lead times on small orders to improve sample and trial testing on enclosure projects. The program provides spliced rings available in a variety of cross sections and can be purchased in either solid or hollow profiles.

In the event that enclosure tolerances are large or the available compressive force is low, Parker engineers can design a custom hollow seal to help absorb large tolerances while providing very low compressive force compared to solid cord. Spliced rings with large inside diameters up to 95” are available in silicone and nitrile materials. Rings with inside diameters up to 57” are available in fluorocarbon. Cross sections of .070”, .103”, .139”, .210” .250” are regularly stocked and available to splice to the ring ID needed. The chart below outlines the current compounds, cross sections, and diameters available under the program. 

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A short, two-week delivery time provides accelerated design validation prior to production launch. On large projects where customers require confirmation that the ring ID will properly fit the application and provide the needed compression force, the Rapid Prototype Program can reduce the overall lead time – increasing the chance of success. To learn more about this new program, contact your local Parker distributor. 

Parker utilizes a hot vulcanizing bonding process to splice our rings. Our bonding material is the same base polymer as the extrusion, giving it equal chemical resistance and physical properties of the seal. 

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Precision extruded and spliced products offer cost effective sealing solutions for many applications. These include low closure force seals, large diameter seals that cannot be molded, or requirements for hollow O-rings, non-standard O-rings and other extruded profiles with an inside diameter larger than 2.500 inches.

Spliced and fabricated seals offer the designer a tremendous amount of flexibility for challenging applications. Products can be vulcanized from a variety of solid and hollow cross-sections. Due to the low tooling cost and flexibility of the extrusion process, customer profiles can easily be designed to specific application needs.

Extruded and spliced products are available in the following material types: silicone, nitrile (Buna-N), EPDM/EPR, HNBR, fluorosilicone, fluorocarbon, and FFKM. Specialty approved materials are also available that are certified to UL (UL 94 V-0 and UL 157), USP Class VI and FDA white listed materials. 

• Precision extrusion tolerances

• Exclusive use of quality sealing grade materials

• Superior hot vulcanization capability (High bond integrity)

• Low closure force sealing solutions

• Ease of adjusting closure force by adjustment of cross section design, cross section I.D., or durometer

• Hollow cross sections are excellent replacements for foam or sponge gaskets, offering superior compression set resistance.

• Interference -fit designs available for ease of installation without use of adhesive

• Pressure Sensitive Adhesive (PSA) backed extrusions available for flat panel sealing applications.

• Low cost option for static face or radial seal O-rings over 2.500" I.D.

• Can be used in standard or non-standard grooves

For more information on the benefits of hollow and solid spliced seals, visit Parker's website and chat with an engineer today!

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This article was contributed by Wesley Burcham, market manager, Parker O-Ring & Engineered Seals Division.

Additional Resources

Sealing Groove-less Applications with Flat Panel Gaskets

Sealing Fundamentals | How to Properly Install a Parker Hollow O-ring

Sealing for Harsh Environmental Conditions in Telecommunications Applications 

Environmental Seal Enclosure 101

Categories

• Sealing & Shielding
• Seals & O-rings

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Clik here to view.Parker Chomerics THERM-A-GAP TC50 is the latest in the family of soft thermal conductive silicone elastomers developed to conduct heat between a hot component and a heatsink or enclosure. The heavy paste-like consistency of this one component putty can be easily dispensed in a controlled manner to produce different thicknesses in line with customer specific application requirements. 

TC50 provides a low thermal impedance at multiple gaps to permit the deployment of commonly used spreaders. In addition, it only requires low compressive force to deform under assembly pressure. As a result, any stress on components, solder joints and leads is minimised.

This one component, RoHS compliant material is formulated to accommodate today’s high-performance electronics and is particularly suitable for volume markets due to ease-of-dispensing using robotics or automation, therefore reducing cycle times and costs considerably.

THERM-A-GAP TC50 is aimed at automotive ECUs (electronic control units), consumer electronics, power supplies and semiconductors, as well as microprocessors, memory and power modules. It can be packaged in syringes or cartridges, or bulk packaged in pails.

Delivering thermal conductivity of 5.5 W/m-K and heat capacity of 1 J/g-K, TC50 is typically suitable for all bond lines over 0.15 mm (0.006 in) thick.

THERM-A-GAP TC50 benefits include.

• High thermal conductivity

• Easy to handle / dispense

• Ideal for high volume applications, such as those in the automotive industry

• Pre-cured

• Can accommodate a variety of bond line applications

• Reworkable

Watch our video of THERM-A-GAP TC50 thermal putty being dispensed below.

Learn more about Chomerics thermal interface materials for electronics cooling. 

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This blog was contributed by Melanie French, marketing communications manager, Parker Chomerics Division Europe. 

Related content: 

New Thermal Gel Benefits Consumer and Automotive Applications

The Benefits of Thermally Conductive, Fully Cured Dispensable Gel

EMI Shielding Caulk Delivers Superior Performance in Military Radar Systems

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Two things are equally important for the reliable performance of an O-Ring seal: the right size and the right material. Parker’s new O-Ring Selector is an engineering tool that enables users to make the right material and size selections easily, quickly and reliably – in a single application. The accuracy of the results ensures the desired performance of the O-Ring in the subsequent application. This is primarily based on the fact that both functionalities – the material selection and the O-Ring size calculation – are closely interlinked. This achieves a new quality in calculating the total sealing system.   

The Parker O-Ring Selector is divided into three main sections:

• Service Conditions & Material Selector
• Size Selector
• Notes

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The Service Conditions & Material Selector section is focused on mapping the material-related application conditions. Entering the operating temperature range, the desired polymer family and/or material hardness will take the user to the suitable material selection. The Advanced Material Selector enables experienced users to specify the operating conditions in even greater detail. Here the medium to be sealed can be selected from a database containing 2,500 media. In addition, a search for required approvals and conformities can be run.

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After the dimensions of the system hardware have been entered, the Size Selector will calculate the dimensions and tolerances of the O-Ring based on international standards. Due to the great flexibility of possible entries, the sealing system will be “modeled” realistically. Factors such as thermal expansion or chemical swelling of the sealing element which are necessary for a precise calculation are taken into account.

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Clik here to view.The Notes section makes it possible for users to add their own comments and remarks to the calculation. Following the O-Ring selection process, the data obtained can be converted into a PDF document and exported.

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>>> Start imperial version
>>> Start metric version

Additional information:
www.parker.com/o-ring-selector

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Posted by:  
Dr. Heinz-Christian Rost
Technology & Innovation Manager
Engineered Materials Group Europe, Prädifa Technology Division

Continuous Molding Enables Production of Large-Size Elastomer Seals in Precision Quality

A Guide to Selecting the Proper Sealing Material for Food Applications

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Clik here to view.A common challenge in the automotive industry is to seal a wide variety of fluids that are being utilized in a host of unique applications. Whether it be due to dynamic motion, component geometry, or a combination of the two, there are many times when an O-ring is not ideal for a part’s sealing needs. When millions of people trust automotive manufacturers with their lives each day, “non-ideal” simply won’t do. Fortunately, Parker has utilized our precision cut and extruded product line to efficiently manufacture solutions to common problems that arise in the automotive industry.

In a transmission, it is the clutch’s job to repeatedly engage and disengage drive shafts from one another to help turn the transmission’s output shaft. This often requires sealing while the clutch is in motion. Parker is able to manufacture D-rings and double chamfer seals that utilize their unique cross-sectional geometry to provide an inherent advantage over O-rings in dynamic situations such as these. The flat base of each of these profiles allows for smooth reciprocating and rotary motion without the potential of bunching, rolling, and/or spiral failure. These products are readily available in AEM or FKM materials, which are often used in transmission applications.

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Clik here to view.A quick look under the hood is all it takes to notice that there are many caps, nozzles, and covers that contain a wide variety of fluids. Antifreeze, coolant, and oil are the traditional fluids found in an engine, but even on the modern-day hybrid or electric vehicle, there are still many components that are covered and need sealing. Parker’s extrusion and splicing manufacturing process allows us to design seals for a wide range of challenges. Our hollow profiles allow for friction fit groove designs which retain themselves in the groove and can be utilized for low closure force on oil pans, hybrid electric battery covers, and under-the-hood sensor covers. Additionally, Parker can extrude and precision cut rectangular cross-section parts or press-in-place seals for an alternative sealing solution to any of the applications previously described. Spliced or precision cut parts can be manufactured in EPDM, Silicone, FKM, NBR, or HNBR materials.

Due to the high degree of customizability with the precision cut and extruded product line, the possibilities of applications are endless. Parker can manufacture flat rubber washers as bumpers or vibration dampers, tubes of material as fluid transfer seals, and other custom or more exotic profiles can be extruded and precision cut into solid grommets for sealing plug holes and other openings.

Vehicles today are made up of thousands of complex components and the technology is continuing to be pushed further each year. As companies continue to innovate, so will the sealing needs and challenges. With virtually endless possibilities for our precision cut and extruded product line, Parker continues to meet and exceed the sealing needs of the automotive industry.

Visit our Seal Solutions eGuide to find the best sealing solution for your application or speak with one of our engineers by using our Live Chat tool.

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This article was contributed by Tyler Karnes, applications engineer, Parker O-Ring & Engineered Seals Division.

Related content:

Seals and the Quest for MPG

O-Rings and Seals for Automotive Transmission Fluid

Rapid Prototype Program Reduces Seal Project Lead Time

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Clik here to view.We receive many requests from customers asking for recommendations on how to retain seals in an application. One of the most popular "quick fixes" is to apply liberal amounts of adhesive to a standard O-ring type product without respect to groove shape or sealing function. However, Parker OES provides a wide array of sealing technologies, offering innovative solutions to accommodate the challenging and vast sealing needs of our customers.

A customer had been using a standard O-ring product on an outdoor electronic device. This part was sealing the external edge of the enclosure and meant to keep out water and dust. The enclosure was plastic injection molded so this extreme edge had irregular geometry to accommodate the molding process. The original proposal was to shove O-ring cord in place and adhere it down with RTV (Room Temperature Vulcanization) so that it did not fall out during assembly. This left a rust colored stripe exposed on a consumer device due to fitment issues. Parker’s proposal was to replace the O-ring cord with a custom hollow extrusion that fit the available space and allowed complete closure, thus not exposing the seal to be visible. The RTV process was replaced with PSA (Pressure Sensitive Adhesive) that was preassembled to the seal and allowed for quick and clean placement during assembly and retention for any maintenance needed.

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A different customer had been using a similar product solution for an industrial cartridge filter. A sheet metal cap had a groove stamped into it and then an O-ring was adhered in place with a cyanoacrylate adhesive (power glue). This was a time consuming, messy step with a relatively costly consumable being used. Parker was able to offer a custom hollow shape that self-retained in the groove due to interference based friction rather than adhesive attachment. It was bonded into a finished ring using Parker’s proprietary splicing technology to give a complete seal around the whole perimeter of the cartridge opening

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The discussion of how to keep a seal located in the right place is one that happens on every application. Sometimes, the answer is as simple as “gravity will hold it.” Other times, a more purposeful solution needs to be pursued. Standard product can be combined with adhesives to achieve the goal. However, Parker has other solutions that do not require that additional time and the expense of another consumable item.  

For more information on custom sealing solutions, visit the Parker O-Ring & Engineered Seals Division website and chat with an engineer today!

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This article was contributed by James Upshur, product engineer, Parker O-Ring & Engineered Seals Division.

Related content:

Sealing Fundamentals | How to Properly Install a Parker Hollow O-ring

Rapid Prototype Program Reduces Seal Project Lead Time

Press-in-Place Seals for Axial Sealing Applications

Advanced compounds extend downhole drilling time. Hydrogenated acrylonitrile butadiene (HNBR) compounds have been developed specifically for downhole mud motor boots. These compounds offer improved mechanical properties, toughness, and fluid resistance leading to extended drill time. See the physical properties listed in the graph below for the HNBR compounds KA261-60, KA271-70, KA281-80, and KB282-80 that Parker has to offer.

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Mud motor boots must perform in harsh environments of drilling fluids and high temperatures without failure, in order to protect the drill string. Boots must operate in a vast array of water and oil based muds specifically formulated to enhance drilling productivity, often at the expense of rubber articles. Specific compounding is required to overcome these obstacles. Downhole temperatures during mud circulation can exceed 300˚F, placing additional stress on the boot. Debris contained in the mud is circulated at high flow rates which can abrade the boot surface, leading to premature failure of the rubber. Operation of the drill string places the boots under severe mechanical loads causing flex and torsional fatigue. Customer feedback has shown that competitive mud motor boots experience field issues, which has driven Parker to the development of new compounds for the market.

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Parker benchmarked industry standard boots using downhole muds and high temperature mechanical properties to validate its newly developed HNBR compounds. The compounds have been evaluated at 350˚F and show performance enhancements over competitive boot compounds. While testing in drilling mud procured from the drilling site, it was determined that the current rubber boots were undergoing chemical degradation leading to premature failure. Parker’s expertise in material compounding overcame the fluid resistance barrier to produce a material that extends the drilling time available. Field testing of the new boots reduced the failure rate to zero.

Take a look at the latest Mud Motor Boot bulletin to learn how Parker partners with its customers in the oil and gas industry to maximize safety, efficiency and profitability.

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This article was contributed by Ericka Norris,  Market Manager, Parker O-Ring & Engineered Seals Division.

Related content:

Advanced Material Development for High-Pressure/High-Temperature Oil & Gas Extraction

Do Your Seals Meet the Demands of the Oil and Gas Industry?

Mud Logging Gas Analysis: Using Hydrogen to Determine Total Organic Content of Samples

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Clik here to view.Precision timepieces operate much like the inner workings for automotive machines. Underneath the back cover lies a series of gears and springs designed to measure the passage of time. We are told how these inner workings are created with such precision that they are able to measure the time accurately over whatever time period that the name brand manufacturer wants to advertise.  

Think about these “precision components” within the watch necessary to create this “machine” whose fastest rotational output is one rotation per minute, compared to an automatic transmission that has components that rotate more than seven thousand RPM!

35 years ago, the world of automotive transmissions moved from three speed boxes to four speed transmissions. In the late 90’s, six speed transmissions were introduced into the market offering improvements in fuel economy and shift quality. In the past five years, many automotive OEM’s launched several eight speed designs. Today, nearly every OEM is either launching or developing nine and ten speed transmissions, with patents being applied for eleven speeds.

The drivers for this progression in development of automotive transmissions is: 

1. fuel economy 

2. drivability, or shift quality

The goal is to make sure the vehicle is in the most optimum gear ratio for whatever speed and acceleration combination the vehicle may be in from zero to whatever the legal speed limit may be in your area. This provides the best fuel economy. The more gear ratios you have available to you; the better chance you have of being in an optimal condition which improves overall efficiency.

From a shift quality point of view, think of it like a staircase. A typical staircase has 11-13 steps in order for a person to comfortably climb. Imagine if you reduced that to six or four steps, each step would be a struggle to walk up making the climb slow and cumbersome. Perhaps you have heard concerns regarding the vehicle “constantly shifting” or driven some of these vehicles with the higher number of speeds. The experience is actually positive in that the shifts are so smooth; you don’t actually feel them.

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Clik here to view.It is important to note that the vehicles are not becoming any smaller. If anything, the trend is for smaller vehicles for better fuel economy. Obviously, a ten speed transmission had many more components than that of a four or six speed, but all of these parts need to fit within the same size transmission case. 

All of the different component groups are therefore fighting for real estate. A typical rear wheel drive transmission is roughly a meter long. In design meetings an entire room full of people may be negotiating over a tenth of a millimeter. This is the average diameter of a human hair. Many of the component tolerances are in the range of a hundredth of a millimeter. We are not only talking about splitting hairs, but we are talking about splitting hairs into ten layers! 

It is inspiring to me to think about these new transmissions and what it takes to put together these precision components and rotate them at more than seven thousand times per minute with enough balance that it doesn’t vibrate the driver out of the vehicle. These machines are just as much a piece of art as the “Precision Timepieces” and Parker is proud to be part of this process.

For more information from the Engineered Materials Group, please visit the Parker Engineered Materials Group Landing page. 

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This blog was contributed by Scott Van Luvender, applications engineering manager, Automotive.

Related content: 

Custom Seals Provide Trusted Results for Automotive Industry Challenges

Seals and the Quest for MPG

O-Rings and Seals for Automotive Transmission Fluid

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Clik here to view.Two things are equally important for reliable performance of an O-ring seal: the right size and the right material. Parker’s new O-Ring Selector is an engineering design tool that enables users to make the right material and size selections easily, quickly and reliably – in a single application. This post explains how to select a material using the “Service Conditions & Material Selector.”

See also Blog Post:
“O-Ring Selection Made Easy with the Parker O-Ring Selector”

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Clik here to view.Selecting the right material for a specific application is a central step in assuring the functionality of an O-ring in the system to be sealed. The “Service Conditions & Material Selector” is focused on mapping the material-related application conditions.

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The “Service Conditions & Material Selector” is used to define the application conditions. The operating temperature range is the minimum input required before the subsequent calculations of the installation conditions and O-ring dimensions can be performed in the “Size Selector.” If already known, the desired polymer group and hardness of the material can be entered here as well.

When an entry is made into a data field the suitable sealing materials will automatically be displayed under “Product Matches. The desired material can be chosen by clicking "Select"

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This is where users can describe the application in even greater detail. In the “Filter by Fluid Compatibility” search field, a wide range of media can be selected and combined as appropriate. The O-Ring Selector has access to a database with more than 2,500 different media for this purpose.

Required approvals and conformities can be selected by means of an appropriate filter as well. The search can either be sorted by groups or a specific certificate can be selected under “Individual Certifications” ranging from AM, DBL, FDA, ISO, MIL through to WL certificates.

To meet specific requirements – such as the recognition of installed O-rings on assembly lines – available materials can also be filtered according to their colors.

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>>> Start imperial version
>>> Start metric version

More information:

Blog: O-Ring Selection Made Easy with the Parker O-Ring Selector

www.parker.com/o-ring-selector

Posted by

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Dr. Heinz-Christian Rost
Technology & Innovation Manager
Prädifa Technology Division

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Dorothy Kern
Applications Engineering Team Leader
O-Ring & Engineered Seals Division

O-Ring Selection Made Easy with the Parker O-Ring Selector

Continuous Molding Enables Production of Large-Size Elastomer Seals in Precision Quality

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Clik here to view.Our applications engineering team takes more than a few calls each month where the O-ring is leaking, either immediately or after just a short time in service. Once we drill down to the details, we learn the failure mode is an improperly sized groove and O-ring. It isn’t all that uncommon for a groove to be cut in a flange and a novice designer learns the hard way that standard O-rings cannot fit in just any groove geometry. For hardware that has already been machined, frustration ensues as the caller learns the O-ring solution requires tooling. Tooling can have a lead time of at least a month to cut and can cost thousands of dollars. Parker offers a TetraSeal® solution, which often does not require tooling and can be made of many of the same materials used for O-rings.

The TetraSeal is a circular precision-cut seal with a square cross-section. Unlike O-rings which require a unique mold for each material family and size, TetraSeals are extruded, cured and machine cut to the target thickness. Our manufacturing facilities in both Spartanburg, South Carolina and Goshen, Indiana are tooled in a variety of interchangeable extrusion dies, making this type of seal an easily sourced seal solution without the lead time and cost of a custom molded O-ring.

The manufacturing process for TetraSeals includes two dimensions on the cross section:Image may be NSFW.
Clik here to view. a cut and a width. However this methodology is used to achieve other seal profiles as well. The flexibility on sizing of precision cut seals allow us to change the square to a rectangle, or other configuration, as an alternate seal solution if it better suits the preexisting groove. This customization can be a great alternative for unconventional groove profiles where an O-ring simply will not work. One common example of an unsuitable groove geometry is having the width too narrow for the depth. Using a seal with a round or  square cross section means choosing proper seal compression at the risk of overfilling the groove or, selecting a smaller cross section for proper volume fill but sacrificing with too low compression. Both of these options can result in leaking or shortened seal life.

Additional benefits to TetraSeals, and other precision cut geometries, are the absence of typical molding surface anomalies (such as parting line flash, non-fills, and dirty mold.) TetraSeals have a smooth, homogenous, radial sealing surface resulting from the extrusion process. Parting line disruptions can be problematic in sensitive radial sealing applications, making the TetraSeal an appealing solution.

TetraSeals can be made with an inner diameter ranging between 0.188 up to 18.000” (4.78 to 457.20 mm) and a thickness of 0.066” up to 0.265” (1.68 to 6.73 mm). In addition, the seals can be made as a direct replacement for many AS568 sized O-rings. Common materials include:

Polyacrylate& Ethylene Acrylate

EPDM

Nitrile and HNBR

Silicone

Fluorocarbon

For more information on TetraSeals or other custom sealing solutions, visit Parker O-Ring & Engineered Seals Division and chat with an engineer today!

*TetraSeal is a registered trademark of Parker Hannifin Corporation. 

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This article was contributed by Dorothy Kern, applications engineering manager, Parker O-Ring & Engineered Seals Division.

Related content:

Environmental Seal Enclosure 101

Innovative Solutions Improving Seal Retention

3 Advantages of a Double Chamfer Radial Seal

Press-in-Place Seals for Axial Sealing Applications

Custom Seals Provide Trusted Results for Automotive Industry Challenges

Image may be NSFW.
Clik here to view.Our applications engineering team takes more than a few calls each month where the O-ring is leaking, either immediately or after just a short time in service. Once we drill down to the details, we learn the failure mode is an improperly sized groove and O-ring. It isn’t all that uncommon for a groove to be cut in a flange and a novice designer learns the hard way that standard O-rings cannot fit in just any groove geometry. For hardware that has already been machined, frustration ensues as the caller learns the O-ring solution requires tooling. Tooling can have a lead time of at least a month to cut and can cost thousands of dollars. Parker offers a TetraSeal® solution, which often does not require tooling and can be made of many of the same materials used for O-rings.

The TetraSeal is a circular precision-cut seal with a square cross-section. Unlike O-rings which require a unique mold for each material family and size, TetraSeals are extruded, cured and machine cut to the target thickness. Our manufacturing facilities in both Spartanburg, South Carolina and Goshen, Indiana are tooled in a variety of interchangeable extrusion dies, making this type of seal an easily sourced seal solution without the lead time and cost of a custom molded O-ring.

The manufacturing process for TetraSeals includes two dimensions on the cross section:Image may be NSFW.
Clik here to view. a cut and a width. However, this methodology is used to achieve other seal profiles as well. The flexibility on the sizing of precision cut seals allows us to change the square to a rectangle, or other configuration, as an alternate seal solution if it better suits the preexisting groove. This customization can be a great alternative for unconventional groove profiles where an O-ring simply will not work. One common example of an unsuitable groove geometry is having the width too narrow for the depth. Using a seal with a round or square cross-section means choosing proper seal compression at the risk of overfilling the groove or, selecting a smaller cross-section for proper volume fill but sacrificing with too low compression. Both of these options can result in leaking or shortened seal life.

Additional benefits to TetraSeals, and other precision cut geometries are the absence of typical molding surface anomalies (such as parting line flash, non-fills, and dirty mold.) TetraSeals have a smooth, homogenous, radial sealing surface resulting from the extrusion process. Parting line disruptions can be problematic in sensitive radial sealing applications, making the TetraSeal an appealing solution.

TetraSeals can be made with an inner diameter ranging from 0.188 up to 18.000” (4.78 to 457.20 mm) and a thickness of 0.066” up to 0.265” (1.68 to 6.73 mm). In addition, the seals can be made as a direct replacement for many AS568 sized O-rings. Common materials include:

Polyacrylate& Ethylene Acrylate

EPDM

Nitrile and HNBR

Silicone

Fluorocarbon

For more information on TetraSeals or other custom sealing solutions, visit Parker O-Ring & Engineered Seals Division and chat with an engineer today!

*TetraSeal is a registered trademark of Parker Hannifin Corporation. 

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This article was contributed by Dorothy Kern, applications engineering manager, Parker O-Ring & Engineered Seals Division.

Related content:

Environmental Seal Enclosure 101

Innovative Solutions Improving Seal Retention

3 Advantages of a Double Chamfer Radial Seal

Press-in-Place Seals for Axial Sealing Applications

Custom Seals Provide Trusted Results for Automotive Industry Challenges

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Clik here to view.Customers often call with various sealing challenges. But sometimes their dilemmas can be solved with more robust solutions instead of direct replacements. For example, when a customer is having issues with a PSA-backed hollow seal that keeps peeling away from the bottom surface. 

If you need to seal a box with a lid, you may need a 4-corner gasket to seal the contents from dirt and moisture. If you use a solid gasket, the compression force may be too great to effectively close the lid. Using a hollow seal reduces the compression force by orders of magnitude, but it comes with its own set of challenges.

A hollow seal for a box will most often seal between two flat surfaces. The bottom surface will be flat for adhesion to the box, while the top surface is curved to engage the lid as it is seated on top of the seal. However, the disadvantage of this design is the tendency of the flat portion to lift off the bottom surface. Figure 1 illustrates this phenomenon with standard Parfab profile D015.

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Figure 1.  Hollow-D profile D015 with 25 percent compression.

In the analysis shown in Figure 1, the bowing is 0.030 inch at its highest point. Due to this tendency to bow upward, it is necessary to use Pressure Sensitive Adhesive (PSA) backing to keep the bottom surface in place during compression. However, due to the bowing of this surface, this stresses the PSA backing every time the seal is compressed. This can cause the PSA backing to eventually peel away. When this happens, the seal can also leak due to lack of seal contact on the bottom surface.

To address this issue, Parker offers the Omega seal profile, which has a hump in the middle of the flat portion to reduce bowing as the seal is compressed.Image may be NSFW.
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Figure 2 shows Omega seal profile W034. Like the D015 profile, it is also 0.500 inch high, and is compressed 25 percent.

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Figure 2.  Omega seal profile W034 with 25 percent compression.

As shown in Figure 2, the bowing of the bottom surface has been reduced from 0.030 inch to 0.004 inch, which greatly reduces peeling stress when PSA backing is used.

Figure 3 illustrates the standard profiles that we offer for the Omega seal profile.

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Figure 3.  Standard Omega seal profiles.

They are also available in a variety of different materials. They can be extruded as cord stock, or supplied as spliced four-corner gaskets for your particular lid or door sealing application.

For more information, visit Parker O-Ring & Engineered Seals Division online and chat with our experienced applications engineers.

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This article was contributed by David Mahlbacher, Parker O-Ring & Engineered Seals Division, product design engineer for general industrial/consumer/on-shore oil & gas. 

Related content:

Rapid Prototype Program Reduces Seal Project Lead Time

Environmental Seal Enclosure 101

Press-in-Place Seals for Axial Sealing Applications

Sealing Groove-less Applications with Flat Panel Gaskets

Image may be NSFW.
Clik here to view.Two things are equally important for reliable performance of an O-ring seal: the right size and the right material. Parker’s new O-Ring Selector is an engineering design tool that enables users to make the right material and size selections easily, quickly and reliably – in a single application. This post explains how to design the sealing system using the “Size Selector.”

See also blog post:

• O-Ring Selection Made Easy with the Parker O-Ring Selector
• How to Select the Right O-Ring Material with the Parker O-Ring Selector

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The “Size Selector” calculates the installation conditions and the suitable O-ring. It is divided into three segments: “Hardware Configuration,” “Sizing Selection” and “Results” (of the calculation).

The “Hardware Configuration” segment is used for a detailed description of the sealing system. The user can choose between two radial (Piston und Rod Seal) and two axial (Internal and External Pressure) sealing systems. Subsequently, these choices can be specified in greater detail by selecting liquid systems or gas/vacuum systems. The selection of the various options is intuitive due to the clear, graphic presentation of the individual sealing systems. 

“Hardware Configuration” also includes a look at the diverse thermal expansion coefficients of the hardware components. Representative values, e.g. for steel or aluminum, are available here. Of course, if known precisely, these values may also be entered manually to parameterize the sealing system with maximum accuracy. Chemical swelling of the seal itself may be included in the calculation as well.

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The “Sizing Selection” segment is focused on the comprehensive calculation of the system to be sealed. If known, all values such as O-ring diameter, piston diameter, etc. can be entered manually. Alternatively – if complete information is not available – an automatic parameterization of the sealing system can be performed via the selection of the O-ring diameter and (for instance) the targeted piston diameter. All the individual values calculated this way can be adjusted manually in a second step and their effects on the functionality of the sealing system reviewed. The toleration of the hardware components can be adjusted to the user’s application as well to satisfy the various quality requirements in the manufacturing process.

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The “Results” segment displays the calculated results in a structured manner. For the key results parameters, the recommendations are shown according to ISO/Parker specifications. In addition, minimum and maximum tolerations for the results parameters are indicated. A simple visual check if the calculated sealing system corresponds to ISO/Parker recommendations is made using color codes: green stands for “Recommended,” yellow for “Warning” and red for “Critical.”  

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Clik here to view.Users can enter their own comments on the calculations made in “Notes.” After the review of the sealing system has been completed, the data obtained can be converted into a PDF.

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>>> Start imperial version
>>> Start metric version

Additional information:

• O-Ring Selection Made Easy with the Parker O-Ring Selector
• How to Select the Right O-Ring Material with the Parker O-Ring Selector
• www.parker.com/o-ring-selector

Posted by:  

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Dr. Heinz-Christian Rost
Technology & Innovation Manager
Engineered Materials Group Europe, Prädifa Technology Division

O-Ring Selection Made Easy with the Parker O-Ring Selector

How to Select the Right O-Ring Material with the Parker O-Ring Selector

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Clik here to view.Präzisions-O-Ringe werden durch Vulkanisation in einem geschlossenen Werkzeug im Kompressions- oder Spritzverfahren hergestellt. Auf diese Weise lassen sich O-Ringe in relativ engen Fertigungstoleranzen und mit guter Oberflächenbeschaffenheit gemäß ISO 3601-1 und ISO 3601-3, herstellen. Aufgrund festgelegter Vulkanisationsparameter weisen Präzisions-O-Ringe gleichbleibend hohe mechanische Eigenschaften über den gesamten Umfang auf. Nur durch dieses hohe Qualitätsniveau können später in der Anwendung gleichbleibend gute Dichtungseigenschaften über einen langen Zeitraum hinweg erreicht werden.

Bisher galt allerdings in der Dichtungsbranche, dass mit diesem Verfahren O-Ringe in sehr großen Abmessungen nicht wirtschaftlich hergestellt werden können. Der Grund liegt im enormen Aufwand und den damit verbundenen hohen Kosten zur Erstellung eines Werkzeugs. Hinzu kommt, dass das äußerst schwierige Handling derartig großer Werkzeuge von vielen Dichtungsherstellern nicht bewältigt werden kann.

Die bei Parker Prädifa eingesetzte innovative Fertigungstechnologie der Endlosvulkanisierung, die ohne störanfällige Stoßstellen auskommt, ermöglicht die wirtschaftliche Herstellung von O-Ringen in Präzisionsqualität mit hoher mechanischer Belastbarkeit in nahezu beliebigen Durchmessern. Die endlosvulkanisierten O-Ringe weisen technisch vergleichbare Eigenschaften auf wie O-Ringe, die im konventionellen Pressverfahren hergestellt werden. Durch das formgebundene Verfahren zeichnen sich diese XXL-O-Ringe als Qualitätsprodukt für anspruchsvolle Anwendungen aus.

Die Oberflächenbeschaffenheiten und Toleranzen entsprechen der ISO 3601:2012. Diese Norm deckt allerdings nur Schnurstärken bis 8,4 mm ab. Um unseren Kunden trotzdem eine zuverlassige und gleichbleibend hohe Qualität der O-Ringe bei Schnurstärken >8,4 mm gewährleisten zu können, hat Parker Prädifa eine eigene Hausnorm auf Basis der ISO 3601:2012 entwickelt.

Neben XXL-O-Ringen in Präzisionsqualität bietet Parker Prädifa auch die Entwicklung und Fertigung kundenspezifischer Geometrien in großen Durchmessern an. Je nach Anwendungs-Erfordernissen steht eine umfangreiche Palette an Werkstoffen zur Verfügung.

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Clik here to view.Die Aufgabe >> Bei der großindustriellen Herstellung halbsynthetischer Antibiotika werden bis zu 500.000 Liter Antibiotika pro Fertigungslos produziert. Damit dies wirtschaftlich möglich ist, werden Anlagen entsprechender Größe benötigt. Neben großen Fermentern mit mehreren Metern Durchmesser, in denen biotechnologisch Antibiotika gezüchtet werden, kommen auch Zentrifugen mit vergleichbaren Abmessungen zum Einsatz, um das Antiobiotikum von den Prozesshilfsstoffen zu trennen. Hierbei darf es sowohl aus Sicherheits- als auch aus wirtschaftlichen Gründen auf keinen Fall zu Leckage kommen. Eine Leckage an den Zentrifugen könnte zu einer Kontamination der Antibiotika, verbunden mit einem entsprechenden hohen wirtschaftlichen Schaden, oder schlimmer, Kontamination der Umgebung mit der damit verbundenenen Gefahr für Mensch und Umwelt führen.

Die Lösung >> Um eine zuverlässige Dichtungslösung zu erarbeiten, wurde Parker Prädifa schon frühzeitig in die Entwicklung mit einbezogen. Durch Einsatz von endlosvulkanisierten, also stoßstellenfreien, Präzisions-O-Ringen ist die zuverlässige Dichtfunktion sichergestellt. Neben dem Dichtungsdesign spielen die Werkstoffeigenschaften, vor allem in puncto Temperatur- und Medienbeständigkeit, bei der Entwicklung eine weitere wichtige Rolle. Neben Dauertemperaturen von 250 °C muss die Dichtung auch den bei der Antibiotikaproduktion eingesetzten aggressiven Medien widerstehen. Zum Einsatz kam der Parofluor® (FFKM)- Werkstoff V8920.

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Clik here to view.Die Aufgabe >> Bei der Neuentwicklung einer Lithografieanlage für die Halbleiterfertigung bestand die Aufgabe in der Abdichtung zweier Gehäusehälften. Aufgrund der Toleranzsituation bei der Fertigung der jeweiligen Gehäusehälften konnte bei montiertem Gehäuse ein Spalt von bis zu 0,5 mm zwischen den beiden Gehäusenhälften auftreten.

Die Lösung >> In der Dichtungstechnik liegen in der Regel zu überbrückende Spaltmaße von 0,05 mm bis 0,25 mm vor. Da größere Spaltmaße bei dem in der Anwendung für die Abdichtung zur Verfügung stehenden Einbauraum mit einer Massivdichtung, wie z.B. einem O-Ring, nicht zuverlässig bzw. nur mit einem erhöhten Leckagerisiko abgedichtet werden können, wurde hierfür keine klassiche O-Ring-Dichtung gewählt, sondern eine Profildichtung im Lippendesign. Die Dichtung wurde unter Einsatz der Finite Elemente Analyse entwickelt, um die zuverlässige Abdichtung großer Spalte und Toleranzschwankungen im Einbauraum der Dichtung zwischen den beiden Gehäusehälften zu gewährleisten. Die Formgebung verhindert darüber hinaus ein Verdrillen der Dichtung bei der Montage und reduziert die erforderlichen Montagekräfte.

Bei der Auswahl des Dichtungswerkstoffes waren hohe Reinheitsanforderungen zu berücksichtigen. Durch entsprechende Nachbehandlungsprozesse erzielt der ausgasarme FKM-Werkstoff V0747 hervorragende Ergebnisse.

Weitere Informationen:

EMG Report 07/2017, Seite 22
Broschüre: Dichtungen und Formteile im XXL-Format

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Clik here to view.Ein Beitrag von
Stefan Reichle, Market Unit Manager Industry
Engineered Materials Group Europe, Prädifa Technology Division

Neuer Dichtungswerkstoff HiFluor FB für hygienisch sensible Anwendungen

Optimale Dichtwirkung, auch bei k(l)einen Drücken mit der HL Stangendichtung

Neuer Werkstoff nobrox erhöht konstruktive Freiheit für Dichtungen und technische Bauteile

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Clik here to view.Zwei Dinge sind für die zuverlässige Funktion einer O-Ring-Dichtung gleichermaßen wichtig: die richtige Größe und der richtige Werkstoff. Der neue O-Ring Selector von Parker ist ein Konstruktions-Tool, das es dem Anwender ermöglicht, einfach, schnell und zuverlässig die geeignete Material- und Größenauswahl zu treffen – in einer einzigen Anwendung. Die Genauigkeit der Ergebnisse stellt die Funktion des O-Rings in der späteren Anwendung sicher. Dies beruht vor allem darauf, dass beide Funktionalitäten – die Materialauswahl und die O-Ring-Größenberechnung – eng miteinander verknüpft sind. Damit wird eine neue Qualität in der Kalkulation des Gesamtsystems „Dichtung“ erreicht.

Der Parker O-Ring Selector ist in drei Hauptbereiche aufgeteilt:

• Service Conditions & Material Selector
• Size Selector
• Notes

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Der Bereich Service Conditions & Material Selector ist auf die Kartierung der materialbezogenen Anwendungsbedingungen ausgerichtet. Durch Eingabe des Einsatztemperaturbereiches, der gewünschten Polymerfamilie und/oder Werkstoffhärte wird der Anwender zur geeigneten Materialauswahl geführt. Der Advanced Material Selector ermöglicht dem erfahrenen Anwender eine noch detailliertere Spezifikation der Betriebsbedingungen. Hier kann das abzudichtende Medium aus einer Datenbank von 2.500 Medien ausgewählt und nach erforderlichen Freigaben und Konformitäten gesucht werden.

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Der Size Selector berechnet nach Eingabe der Abmessungen der Systemhardware die Maße und Toleranzen des O-Rings auf Basis internationaler Standards. Die Eingabemöglichkeiten sind dabei sehr flexibel gestaltet, so dass eine der Realität entsprechende „Abbildung“ des Dichtungssystems ermöglicht wird. Dabei werden die für eine präzise Kalkulation notwendigen Faktoren wie die thermische Ausdehnung oder die chemische Quellung des Dichtelements berücksichtigt.

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Clik here to view.Der Bereich Notes ermöglicht es dem Anwender, die Berechnung um eigene Kommentare und Anmerkungen zu ergänzen. Die ermittelten Daten können nach Abschluss des O-Ring-Auswahlprozesses in ein PDF-Dokument konvertiert und exportiert werden.

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>>> Metrische Version starten
>>> Zöllige Version starten

Weitere Informationen:
www.parker.com/o-ring-selector
 

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Ein Beitrag von
Dr. Heinz-Christian Rost
Technology & Innovation Manager
Engineered Materials Group Europe, Prädifa Technology Division

Endlosvulkanisierung ermöglicht Herstellung von Elastomerdichtungen mit großen Durchmessern in Präzisionsqualität

Leitfaden zur Auswahl des Dichtungswerkstoffes für Lebensmittel-Anwendungen

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Clik here to view.Zwei Dinge sind für die zuverlässige Funktion einer O-Ring-Dichtung gleichermaßen wichtig: die richtige Größe und der richtige Werkstoff. Der neue O-Ring Selector von Parker ist ein Konstruktions-Tool, das es dem Anwender ermöglicht, einfach, schnell und zuverlässig die geeignete Material- und Größenauswahl zu treffen – in einer einzigen Anwendung. In diesem Beitrag wird die Materialauswahl mit Hilfe des „Service Conditions & Material Selector“ erläutert.

Siehe auch Blog Post:
„O-Ring-Auswahl leicht gemacht mit dem Parker O-Ring-Selector“,

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Clik here to view.Die Auswahl des richtigen Materials für eine bestimmte Anwendung ist ein zentraler Schritt zur Sicherstellung der Funktionsfähigkeit des O-Rings im abzudichtenden System. Der „Service Conditions & Material Selector“ ist auf auf die Kartierung der materialbezogenen Anwendungsbedingungen ausgerichtet

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Im Bereich „Service Conditions & Material Selector“ erfolgt die Definition der Anwendungsbedingungen. Um die nachfolgenden Berechnungen der Einbausituation und der O-Ring-Abmessungen im Bereich „Size Selector“ durchführen zu können, ist die Angabe der Anwendungs-Temperaturbereiches als Minimum erforderlich. Auch können, wenn bereits bekannt, die gewünschte Polymergruppe („Polymer Group“) und die Härte des Materials ausgewählt werden.

Erfolgt eine Eingabe in ein Datenfeld, werden automatisch die passenden Dichtungswerkstoffe unter „Product Matches“ angezeigt. Über einen Klick („Select“) lässt sich das gewünschte Material auswählen.

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Hier kann ein noch feineres Bild der Anwendung gezeichnet werden. Im Suchfeld Medienkompatibilität („Filter by Fluid Compatibility“) lassen sich eine Vielzahl unterschiedlichster Medien auswählen und gegebenenfalls miteinander kombinieren. Dabei greift der O-Ring Selector auf eine Datenbank mit über 2.500 unterschiedlichen Medien zu.

Auch erforderliche Freigaben und Konformitäten der Werkstoffe können durch einen entsprechenden Filter festgelegt werden: Die Suche kann entweder nach Gruppen sortiert erfolgen oder es kann unter „Individual Certifications“ ein bestimmtes Zertifikat ausgewählt werden. Die Spannweite reicht von AM-, DBL-, FDA-, ISO-, MIL- bis hin zu WL-Zertifikaten.

Um spezifische Anforderungen – beispielsweise die Erkennung verbauter O-Ringe an Montagelinien – zu erfüllen, können die verfügbaren Materialien auch nach Farbgebung gefiltert werden.

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>>> Metrische Version starten
>>> Zöllige Version starten

Weitere Informationen:

Blog: O-Ring Auswahl leicht gemacht mit dem Parker O-Ring Selector

www.parker.com/o-ring-selector

Ein Beitrag von

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Dr. Heinz-Christian Rost
Technology & Innovation Manager
Prädifa Technology Division

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Dorothy Kern
Applications Engineering Team Leader
O-Ring & Engineered Seals Division

O-Ring Auswahl leicht gemacht mit dem Parker O-Ring Selector

Endlosvulkanisierung ermöglicht Herstellung von Elastomerdichtungen mit großen Durchmessern in Präzisionsqualität

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Clik here to view.Zwei Dinge sind für die zuverlässige Funktion einer O-Ring-Dichtung gleichermaßen wichtig: die richtige Größe und der richtige Werkstoff. Der neue O-Ring-Selector von Parker ist ein Konstruktions-Tool, das es dem Anwender ermöglicht, einfach, schnell und zuverlässig die geeignete Material- und Größenauswahl zu treffen – in einer einzigen Anwendung. In diesem Beitrag wird die Auslegung des Dichtsystems mit Hilfe des „Size Selectors“ erläutert.

Siehe auch Blog Posts

• O-Ring Auswahl leicht gemacht mit dem Parker O-Ring Selector
• O-Ring-Werkstoffauswahl mit dem Parker O-Ring Selector 

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Im Bereich „Size Selector“ (Größenauswahl) erfolgt die Berechnung der Einbausituation und des geeigneten O-Rings. Dabei unterteilt sich der „Size Selector“ in drei Segmente. Die „Hardware Configuration“, die „Sizing Selection“ und die Ergebnisse der Berechnung („Results“):

Im Segment „Hardware Configuration“ erfolgt eine detaillierte Beschreibung des Dichtungssystems. Dabei kann zwischen zwei radial abdichtenden (Piston und Rod Seal) und zwei axial abdichtenden (Internal und External Pressure) Dichtungssystemen gewählt werden. Diese lassen sich dann jeweils weiter durch die Auswahl von Flüssigsystemen oder Gas-/Vakuumsystemen spezifizieren. Die Auswahl der verschiedenen Optionen ist aufgrund der klaren graphischen Darstellung der einzelnen Dichtungssysteme intuitiv.

Die „Hardware Configuration“ schließt auch die Betrachtung der unterschiedlichen thermischen Expansionskoeffizienten der Hardware-Komponenten mit ein. Hier kann auf repräsentative Werte beispielsweise für Stahl oder Aluminium zurückgegriffen werden. Bei genauer Kenntnis können die Werte aber natürlich auch manuell eingetragen werden, um eine möglichst genaue Parametrisierung des Dichtungssystems zu erreichen. Auch kann die chemische Quellung der Dichtung selbst in der Kalkulation berücksichtigt werden.

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Das Segment „Sizing Selection“ konzentriert sich auf die umfassende Berechnung des abzudichtenden Systems. Wenn bekannt, können alle Werte wie O-Ring-Durchmesser, Kolbendurchmesser etc. manuell eingetragen werden. Es kann jedoch auch – bei  nicht vollumfänglicher Informationslage – über die Auswahl des O-Ring- Durchmessers und beispielsweise des angestrebten Kolbendurchmessers eine automatische Parametrisierung des Dichtungssystems durchgeführt werden. Alle so berechneten Einzelwerte können in einem zweiten Schritt manuell angepasst und die Auswirkung auf die Funktionsfähigkeit des Dichtungssystems betrachtet werden. Die Tolerierung der Hardware-Komponenten kann ebenso dem realen Fall angepasst und somit den unterschiedlichen Qualitätsanforderungen im Herstellungsprozess Rechnung getragen werden.

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Im Segment „Results“ werden die kalkulierten Ergebnisse strukturiert dargestellt. Für die wichtigsten Ergebnisparameter werden Empfehlungen (Recommendation) gemäß ISO-/Parker-Spezifikationen dargestellt. Weiterhin werden Minimal- und Maximal-Tolerierungen für die Ergebnisparameter angezeigt. Eine einfache visuelle Überprüfung, ob das kalkulierte Dichtungssystem den ISO- / Parker- Empfehlungen entspricht, erfolgt über eine entsprechende farbige Kennzeichnung: grün steht für „Empfehlung“ („Recommended“), gelb für „Warnung“ („Warning“), rot für „kritisch“ („Critical).

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Eigene Kommentare zu den durchgeführten Kalkulationen können im Bereich „Notes“ erfasst werden. Ist die Betrachtung des Dichtungssystems abgeschlossen, können die ermittelten Daten in ein PDF konvertiert werden.

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>>> Metrische Version starten
>>> Zöllige Version starten

Weitere Informationen:

Blig: O-Ring Auswahl leicht gemacht mit dem Parker O-Ring Selector

Blog: O-Ring-Werkstoffauswahl mit dem Parker O-Ring Selector 

www.parker.com/o-ring-selector

Ein Beitrag von

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Dr. Heinz-Christian Rost
Technology & Innovation Manager
Prädifa Technology Division

O-Ring Auswahl leicht gemacht mit dem Parker O-Ring Selector

O-Ring-Werkstoffauswahl mit dem Parker O-Ring Selector

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Clik here to view.Frequently, our team in Applications Engineering receives a question along these lines: “Is your compound E0740 peroxide cured?” Usually, these questions are asked because an end customer specifies cure system as a requirement on the drawing for the part. Parker considers the ingredients used in our manufacturing process as a trade secret and are not at liberty to directly disclose what cure system is used for any given compound. However, there is a valid and scientific basis behind why customers are concerned with the cure systems of the O-ring material, but is it as critical as it seems?

When uncured rubber is subjected to high temperature and pressure, the polymer chains that make up the rubber material are being locked into place due to cross-linking. Cross-linking is when chemical bonds are formed between individual polymer chains and is what allows rubber to go from a sticky, soft playdough-like material to a solid, sturdy seal. To facilitate this reaction, cure agents are added into the raw compound. These substances form the cross-links while the parts are being molded. The key result of curing the rubber is that curing drastically affects the material properties for a given compound. Two compounds could theoretically be the same up until the point of curing, but once the rubber is cured, these two compounds would have very different material properties.

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Clik here to view.Depending on the base polymer, there are different options for what cure system can be used during manufacturing. In general, each polymer family has at least two options for cure, each providing a different set of finished material properties. In addition to final material properties, cure systems can also differ in cost, with the costlier cure system typically resulting in a more desirable set of final properties for seal applications. Often when customers are specifying a cure system, their intended end-result is to obtain a material with a particular set of properties. A common example of this was laid out above, when a customer may ask whether “E0740 is peroxide cured.” In practicality, what they likely want to know is “Does E0740 have a high resistance to compression set, high tensile strength, and better-than-average high temperature resistance?” These are the properties that result from an EPDM material being peroxide cured. If, in some crazy advancement of science, we discovered that barbecue sauce provided EPDMs with material properties superior to that of peroxide while being less expensive, specifying a “peroxide cure” would no longer be beneficial, as the finished material properties of a peroxide-cured-compound would be inferior and more expensive than those obtained through barbecue-sauce-curing. While that is certainly a silly example, one day in the future, a new technology will be developed and rubber materials will be cured with different substances than what is currently considered to be “mainstream” technology.

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Clik here to view.When someone asks about the cure systems of a compound, our protocol is to understand more about the customer’s application. Each option for cure system of a rubber family has its advantages and disadvantages. Understanding each customer’s specific application tells us what properties are going to be critical in the material selected for their application. For nitrile compounds, many customers prefer peroxide curing, which typically provides increased compression set resistance, higher temperature performance, higher ultimate tensile strength, and increased chemical resistance. However, there are other customers who, maybe in the case of dynamic sealing, would prefer sulfur cure, which would provide better wear resistance, is more cost effective, provides higher ultimate elongation, and improves the ability to withstand repetitive bending. When it comes to sealing, it’s not always about how you got there, but whether or not you get the right material that gets the job done! 

For more information or to speak with an engineer about your specific application, use our Live Chat tool or give us a call. 

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This article was contributed by Tyler Karnes, applications engineer, Parker O-Ring & Engineered Seals Division.

Related content:

Chemical Compatibility: A Critical Component in Seal Design

Perfluoroelastomer Materials Tailored for Your Needs

New CPI FFKM Extends Seal Life, Solving Long Time Industry Challenge  

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Clik here to view.The utilization of suitable materials based on specialized engineering and manufacturing know-how makes it possible to integrate several parts and/or functions in a single assembly component. In many cases, this can shorten the process chain and reduce logistics and assembly requirements. In the case of hygienically sensitive applications such as those in the food industry, a reduction of the number of components enhances hygiene and ease of use, as the number of interfaces and joints decreases as well. As a result, the need for long and costly cleaning cycles is eliminated and the frequently necessary partial dismantling of equipment for maintenance and cleaning can be accomplished with much greater ease and in less time.

The brew unit is the centerpiece of any fully automatic coffee machine. This is where the key parameters of the coffee’s quality are determined, such as the compaction level of the grounds, water pressure and filtering of the coffee product.

The brewing chamber, the metallic micro-strainer and, last but not least, the brewing piston with the associated sealing and wiping system are the key components of the brew unit. 

Conventional brewing piston systems in professional fully automatic coffee machines frequently consist of complex, metallic brewing pistons with sophisticated geometries and failure-prone sealing systems with an average expected lifetime of approximately 50,000 brewing cycles. Afterwards, the brewing piston and the related sealing system have to be exchanged in a time-consuming and costly process.  

The sealing system not only has to withstand a pressure of up to 20 bar at temperatures of 95 °C, but also resist the highly abrasive coffee powder and the acidic coffee extract.

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• The newly developed brewing piston system features two major components: the brewing piston and the portafilter with integrated sealing, wiping and filtering function. Easy connection of the components can optionally be achieved by a threaded connection or snap fitting for ease of assembly and servicing.

• The fully integrated design of the nobrox® brewing piston reduces the geometric complexity and number of single components while increasing ease of assembly and servicing.

• The piston attachment combines various functions, which helps reduce the complexity and component diversity of the brew unit. This where the non-reinforced nobrox® material can display its advantages. Its high wear resistance makes it possible to combine the sealing and wiping function in a dynamic sealing system. The sealing/wiping lip is preloaded by a TPU O-Ring and ensures consistently good sealing performance between the brewing piston and the brewing chamber across the entire lifetime.

• Service life extended on average by 50 to 100 % or to an average expected life of > 100,000 brewing cycles.

• Lower heat loss compared with metallic pistons saves heating elements.

• Manufacturing cost benefits due to injection molding technology compared with machining of metallic brew pistons.

• Unlike solution concepts that enclose the seals in a groove on the outer piston diameter the fully integrated system permits absolutely no dead space. This avoids coffee deposits that impair functionality or flavor. Due to the outstanding tribological properties of the nobrox® material, there is no need for additional lubrication. 

• EMG Report 04/2015 Page 7, Universal nobrox Material in Professional Coffee Machines
• EMG Report 06/2017 Page 10, Universal Material nobrox for Food Applications
• Brochure "Materials for the Chemical Process and Food Industries"
• www.nobrox.com - Food Applications

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Article contributed by

Stefan Reichle, market unit manager industry
Engineered Materials Group Europe, Prädifa Technology Division

Universal Material nobrox® for Food Applications: Compound Versatility Beats Compound Variety

A Guide to Selecting the Proper Sealing Material for Food Applications

New Sealing Material HiFluor FB for Hygienically Sensitive Applications

New Material nobrox Increases Design Freedom for Seals and Engineered Components

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Clik here to view.Electric vehicles are developing fast in line with growing demand. However, only by selecting proven, reliable, high-quality products for the effective thermal management and EMI shielding of batteries, is it possible to maximize performance.

Although electric vehicles represent a greener and cleaner future, they come with a number of technology challenges, including within the battery pack. When large batteries need to provide as much power as possible to supply energy to the car, they generate a considerable amount of heat that must be dissipated. Left unchecked, excessive heat can cause faster battery wear, reduced performance and reduced charge efficiency, not to mention the obvious safety hazards associated with thermal runaway of the battery packs.

Effective thermal management is therefore critical to optimize battery performance and longevity with improved safety and reliability, allowing vehicles to travel greater distances and increasing the achievable run-time on a single charge. 

1. High volume thermal dispensable gels, such as the THERM-A-GAP GEL family, can be dispensed between the coils and the aluminum chassis of the battery to deliver long-term thermal stability and performance. These gels are particularly suitable in volume markets such as automotive due to the ease of dispensing using robotics or automation, thus reducing cycle times and costs considerably. 
2. Thermally conductive gap filler pads are an alternate solution depending on the design of the battery packs. Products such as the THERM-A-GAP gap filler pad family are perfect for assemblies that might require some additional support and higher electrical isolation. 

In addition to effective thermal management, another technology challenge presented by the growing demand for electric vehicles is the need to shield against electromagnetic interference (EMI). The cables that travel between the battery and engine, as well as the battery and charger, see high current produced at low frequency. This produces a large magnetic field that can negatively affect other electronics within the vehicle. High shielding attenuation is also required to protect the battery and its circuits from any incoming EMI.

3. Conductive elastomers can be used to overcome these issues. These elastomers, such as the CHO-SEAL family of elastomer gaskets, are filled with conductive particles and connect interfacing components to reduce the air gap and create a Faraday Cage that blocks EMI fields. Oftentimes, batteries also need to be sealed against environmental dust/fluids. Here, it is possible to deploy combined solutions to support EMI and environmental shielding/sealing. 

4. Form-in-place (FIP) conductive gaskets can be used for battery applications which require shielding of the electric traction elements. FIP can be robotically dispensed directly onto castings making it a low cost option. 

5. Electrically conductive plastic, which can replace the metal housing of the battery ECU, can eliminate 35% of the housing weight, and provide cost reductions of up to 65% by eliminating secondary operations. PREMIER PBT-225 is a single pellet electrically conductive polybutylene terephthalate that offers many comparable properties to those of aluminum, along with weight reduction which helps improve the performance of electric vehicles. 

Learn more about Parker Chomerics' EMI shielding and thermal management technologies for electric and hybrid vehicles. 

This article was contributed by:

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Tiberius Recean - sales manager, automotive

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David Beresford, marketing and technology manager, Chomerics Division Europe.

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Precision O-rings are manufactured by vulcanization in a closed mold using compression or injection molding. This makes it possible to produce O-rings in relatively small manufacturing tolerances and with good surface quality according to ISO 3601-1 and ISO 3601-3. Due to defined vulcanization parameters, precision O-rings exhibit consistently high mechanical properties across the entire circumference. This high quality level is an indispensable prerequisite for achieving consistently good sealing effects over a long period of time.

However, up to now, this production technology has been regarded in the sealing industry as not being economically feasible for O-rings in very large dimensions due to the enormous work and related costs involved in making extra-large molds. In addition, such large molds are extremely difficult to handle and therefore cannot be accomplished by many seal manufacturers.

The innovative manufacturing technology of continuous vulcanization used by Parker Prädifa, which does not involve failure-prone joints, enables the cost-efficient production of precision-quality O-rings with high mechanical load resistance in nearly any desired diameter. The technical properties of continuously vulcanized O-rings are comparable with those of O-rings produced by conventional compression molding. As a result of being molded, these XXL O-rings are quality products for challenging applications.

The surface qualities and tolerances correspond to those in ISO 3601:2012. However, this standard only covers cord thicknesses of up to 8.4 mm. To ensure that customers receive reliable and consistently high-quality O-rings where cord thickness is >8.4 mm, Parker Prädifa has developed an in-house standard based on ISO 3601:2012.

In addition to precision-quality XXL O-rings, Parker Prädifa offers the development and production of customer-specific geometries in large diameters. A wide range of materials is available according to the application requirements.

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The challenge >> In the large-scale industrial production of semi-synthetic antibiotics, up to 500,000 liters of antibiotics are produced per batch. For such large-scale production to be economically feasible equipment of corresponding dimensions is required. In addition to large fermenters with diameters of several meters in which the biotech antibiotic is bred, centrifuges of similar dimensions are utilized to separate the antibiotic from process agents. Leakage must be prevented at all cost for safety and economic reasons. A leaking centrifuge might contaminate the antibiotics, resulting in high financial losses or, worse yet, in health and environmental hazards.

The solution >> Parker Prädifa was involved in the project at an early stage to develop a reliable sealing solution. The utilization of continuously vulcanized, i.e. jointless precision O-rings ensures the requisite reliability. Besides the seal design, the compound properties, particularly temperature and media resistance, play a key role. In addition to permanent temperatures of 250 °C, the seal has to withstand the aggressive media used in antibiotics production. The Parofluor® (FFKM) compound V8920 was selected as the suitable material for this application.

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The challenge >> The development of a new lithography system for semiconductor manufacturing posed the challenge of sealing two halves of a housing. Due to the tolerance situation in producing the respective housing halves, there was a risk of a gap of up to 0.5 mm occurring between the two halves in the assembled housing.

The solution >> In sealing technology, the gap dimensions to be bridged are typically between 0.05 mm and 0.25 mm. As larger gap dimensions available for sealing in the groove in this application could not be reliably sealed, or only by entailing a higher risk of leakage, with a solid seal such as an O-ring, a conventional O-ring sealing solution was not selected here, but a profile seal featuring a lip design. This seal was developed using Finite Element Analysis (FEA) to ensure reliable sealing of large gaps and tolerance variations in the seal groove between the two halves of the housing. In addition, the shape of the seal prevents twisting during installation and reduces the required assembly forces.
In the selection of the seal compound, high purity requirements had to be considered. Due to specific post-curing processes, the FKM compound V0747 with low outgassing properties achieves outstanding results.

More information

EMG Report 07/2017, Page 22
Brochure: XXL Size Seals and Molded Parts

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Stefan Reichle, Market Unit Manager Industry
Engineered Materials Group Europe, Prädifa Technology Division

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