Tag Archives: DuPont

Kalrez PV8070 Parts in Reactors

High Performance Seals for Polycrystalline Silicon Process Equipment

The Challenge

To meet growing demand in solar cells, the Siemens* process is used to produce highly purified polycrystalline silicon by thermally decomposing tri-chloro-silane (TCS). The reactors employed require three kinds of high-performance seals in the following locations: A) bell jar seals; B) electrode seals between the electrode and ceramic inlet; and C) a gasket for the view port seal (see schematic).

pv8070 seals in Polycrystalline Silicon Process Equipment

Application Details

The process involves a very hot, dry environment with temperatures up to 1200°C (2100°F). Sealing components see up to 300°C (572°F). Process media include TCS and aggressive by-products of its decomposition, such as HCl gas. Superior compression set performance is needed for effective sealing and extended seal life. Very low outgassing is a key requirement for preventing contamination of the process environment.

The presence of harsh chemicals in high temperature conditions often require an upgrade from standard sealing materials to PTFE or fluoroelastomers (FKM) to improve thermal stability and chemical resistance. However, PTFE can deform and creep “hot flow” in the bell jar seal increasing the risk of product loss. FKM, with its high temperature rating of 200°C (392°F), also has deficiencies in this 300°C (572°F) environment.

The Solution and Key Advantages of Kalrez PV8070

Kalrez PV8070 perfluoroelastomer parts installed as washers and gaskets in reactors for the Siemens CVD process have demonstrated outstanding performance in this demanding application. Kalrez® PV8070 parts are effective seals that provide: Continue reading Kalrez PV8070 Parts in Reactors

What Makes Kalrez® Different?

Oil and gas production and chemical manufacturing industries present sealing technologies with some of the harshest and most demanding operating environments.

Harsh and Demanding Operating Environments Require Chemically Resistant and Thermally Stable Seals

“We screen Kalrez against some of the most aggressive corrosive fluids,” says Dr Christopher Bish, Technical Fellow. “And in addition to the fluid testing, we did some compression set testing and stress relaxation testing at high temperatures. We now have one of the most chemically resistant and thermally stable compounds possible.”

We screen Kalrez against some of the most aggressive corrosive fluids

What really makes Kalrez sealing technology superior and more durable than competitors?

One of the things that sets Dupont Kalrez apart is their quality control system, which gives them the ability to track materials as they flow through the plant. Scanning the barcode on the part bag can pull up the entire production history of that part, including raw materials and process conditions.

Is Every Kalrez Seal Inspected?

Elastomer Seal: Perfluoroelastomer Parts

Dupont performs a 100% visual inspection. It’s one way to ensure the quality rate is high and the return rate is virtually non-existent.

Despite the foreseen images of clean rooms, manufacturing in the semiconductor industry can be a harsh environment and cost of o-ring and seal replacement is significant.

“Kalrez parts are used as sealing materials in semiconductor wafer processing equipment, where high temperatures, aggressive chemicals, and plasmas are used. The most important thing for Kalrez sealing prodcuts is that the materials are resisting those aggressive conditions and not degrading  or contaminating the chambers,” says  Dr. Shuhong Wang, Technical Fellow.

Chemical and Science That Makes Kalrez Better

The polymer chains are fully fluoronated, forming one of the most inert polymer structures possible. Other elastomers have weak points along the chain structure, which are vulnerable to chemical attack and thermal instability. This, in combination with the unique cross-link technologies, many of which are patented, provides optimum durability and protection.

Check out a tour of one of the Kalrez manufacturing plants and learn what makes it the best choice for your demanding applications.


The original video can be seen on the Dupont website.

For more information, or to find which compound is best for you, contact Gallagher Seals. We are an exclusive distributor of Kalrez® seals.

Switching from PTFE to Kalrez® O-Rings Increase Life by 6,000%

The Seal Challenge

The filling line at Dow AgroSciences plant in Drusenheim, France – a global leader in pest management and biotechnology products – processes aggressive solvents, surfactants and concentrated herbicides at temperatures ranging from 10 to 45 °C, and pressures from 1.5 to 3.5 bars Eff. Filling machine valves on the line were fitted with dynamic PTFE O-rings, while the machine hoses were equipped with static O-rings, also of PTFE.

Each time the mechanical maintenance team performed a clean-in-place procedure at 80 °C, or made a product change on the filler, the PTFE seals became mechanically damaged. This meant they had to change the PTFE O-rings on a daily basis, since seal lifetime never extended beyond 24 hours before replacement.

In a different application at the same plant, seals of FEP/FKM, fitted to the piston rod of a Type SRC Alfa Laval valve, failed regularly after only 8 hours operation.

The cost to Dow AgroSciences in extra performance time and maintenance had become unacceptable, and the company sought a much more resilient sealing material that would better withstand frequent cleaning and product changes.

picture of kalrez as ptfe replacement

The Kalrez® Spectrum™ 6375 Solution

Dow Agro Sciences S.A. installed Kalrez 6375 perfluoroelastomer O-rings to replace the PTFE seals, with dramatic and immediate improvement.

They managed to extend the lifetime of dynamic and static seals fitted to their product filling line from one day to an average of two months, an improvement of some 6000%.

Also the seals of FEP/FKM, fitted to the piston rod of a Type SRC Alfa Laval valve, were replaced by Kalrez perfluoroelastomer parts. Operating lifetime has increased from 8 hours to between 8–12 months!

Kalrez 6375 parts are designed specifically for the chemical process industry. They provide outstanding performance in an extremely wide range of chemicals including acids, bases, amines and steam. The innovative patented curing system allows for continuous upper service temperatures of up to 275 °C in applications such as mechanical seals, valves, flanges and pumps where elastomeric sealing is critical.

In addition, Kalrez is a thermoset perfluoroelastomer part and offers excellent elastic properties and resistance to mechanical damage, unlike PTFE which is a thermoplastic and appears to lack the necessary resilience to withstand mechanical shock in a process application such as this.

Key Advantages of Kalrez 6375

Since switching to custom Kalrez 6375 O-rings Dow AgroSciences S.A. reports an average seal lifetime of two months. That’s an increase of approximately 6,000% over the previously fitted PTFE seals.

The operating lifetime of the seals fitted to the piston rod of a Type SRC Alfa Laval valve increased from 8 hours to between 8–12 months.

Switching to Kalrez® Spectrum™ 6375 parts allowed Dow AgroSciences to increase the operating uptime of their filling machines and to improve overall reliability of their packing line. They have also significantly reduced the time spent in O-ring replacement. The Mechanical Maintenance Manager also reported cost savings as a result of major improvements in safety and reliability, and in reduced maintenance.


Gallagher Fluid Seals is a preferred distributor of Dupont Kalrez® products. For more information or to speak with an engineer, visit Gallagher Fluid Seals or call 1-800-822-4063.

Kalrez® Parts Extend Service Life for Process Instrument

The Challenge

By switching from gasket seals of PTFE to custom gaskets of DuPont™ Kalrez® perfluoroelastomer parts in the sensor head of a process instrument refractometer used by the food, pulp and paper and chemical industries, process instrument manufacturer K-Patents Oy, Vantaa, Finland, was able to dramatically extend instrument service life, increase reliability and safety, and reduce costs for the company and its customers.

Instrument - Refractometer
Delicate digital detector circuits and fibre optics in the sensor head of K-Patents’“PR-01-S” process refractometer are sealed from attack by aggressive process media, temperatures from –20 ° to +220 °C, and pressures from –0,7 to +25 bar, by two DuPont™ Kalrez® gaskets situated either side of the vital Spinel prism

The Solution

Aggressive environment
Through permanent in-line fluids immersion, K-Patents’ “PR-01-S” refractometer is exposed to temperatures      from –20 ° to +220 °C, pressures from –0,7 to +25 bar, and some 500 process fluids and chemicals, many of which are extremely aggressive. Delicate digital detector circuits and fiber optics in the sensor head are sealed by two gaskets from attack by aggressive fluids. Because of inherent inelasticity, the original PTFE gaskets could not withstand the dynamic temperature fluctuations of many food, pulp and paper and chemical manufacturing processes, creating a leak path allowing process media to enter and damage the device. As a result, costly replacement of the PTFE seal became necessary approximately every 6–12 months.

Continue reading Kalrez® Parts Extend Service Life for Process Instrument

Kalrez® Seals for Semiconductor Processing

Purity is critical to high wafer yield, and Kalrez® seals are designed with properties that help reduce contamination from particulates, outgassing and extractables.

Semiconductor Processing Seals

Kalrez® Seals - Semiconductor ProcessingKalrez® seals for semiconductor processing are field-proven in the manufacture of semiconductor chips.

They can help extend planned maintenance intervals, and thereby lower long-term cost of ownership, in a wide range of semiconductor processes. In a number of fabrication customer evaluations, Kalrez®seals exhibited improved mechanical strength, lower particle generation and longer seal life versus competitive perfluoroelastomers, in both static and dynamic sealing applications.

Operational Improvements

Kalrez® seals can help improve semiconductor manufacturing in a range of wafer-fabricating operations, including:

  • Deposition
  • Etch
  • Ash/strip
  • Thermal
  • Wet

Continue reading Kalrez® Seals for Semiconductor Processing

Selection Requirements for Elastomeric Seals

Selection Requirements for Elastomeric SealsGallagher Fluid Seals is a proud of its longtime partnership with DuPont®, having specified thousands of perfluoroelastomer parts over the past few decades.

DuPont is at the forefront of perfluoroelastomer development, creating elastomers with properties that can help meet highly specific application requirements.

But how do you know which elastomer is right for your application? DuPont provides this helpful guide.

Continue reading Selection Requirements for Elastomeric Seals