Momentive Performance Materials and Effbe/Woco Produce Heat Shield Gasket for Ariane 5 Boosters Using Liquid Silicone Rubber (LSR) – Ready for the Guinness Book of World Records

LEVERKUSEN, GERMANY, 24TH OCTOBER 2007

From November 2003 through the spring of 2004, Effbe, a member firm of Woco Group, collaborated with the Woco expert center for Liquid Silicone Rubber (LSR) to develop a production-ready model of a heat shield gasket for the two nozzles on the European Ariane 5 boosters made entirely of liquid silicone rubber from Momentive Performance Materials formerly known as GE Bayer Silicones.

As the European Ariane 5 booster rocket first lifted off on February 12, 2005 from Kourou in French Guyana, everyone involved in the project was in a state of exhilaration. Particularly thrilled were those in charge of the project at Effbe and Momentive Performance Materials, both of which had played a major role in this success with their work on this unusual effort to produce heat shield sleeves for the two nozzles of the Ariane 5 boosters. It was a project that was not only completed in an incredibly short time frame, but also produced a solution that was no less record-breaking on its own.

Gasket production using injection molding

As part of the Industrial Polymer Systems (Woco IPS) division at Woco Group, Effbe primarily specializes in the field of industrial applications for seafaring, air and spaceflight, systems engineering, and general transportation. Effbe was given the contract for the project in 2003 by Snecma, a developer and manufacturer of engines and motors for air and spaceflight and a subsidiary of the Safran Group. Prior to this Snecma had produced the heat shield gaskets for the two nozzles on the boosters individually by hand at great expense. Effbe suggested replacing this process with gasket production using injection molding techniques – a simpler and less expensive solution for producing these parts while maintaining the previous high quality standards, but a process that was extraordinary nonetheless.

An absolute first

“The use of LSR from Momentive in this project is unique,” explains Alexander Widmayr, Woco’s Project Manager for Precision and LSR Parts, “as liquid silicone rubber is normally only used for manufacturing small parts.”

In contrast, the heat shield gasket is a component with unusually large dimensions: with an external diameter of 1.75 meters and a weight of almost 60 kilograms, it would be an easy candidate for the Guinness Book of World Records. To this extent, the project was not entirely without risks because it was entering new territory.

“The risk in this case was especially high due to the fact that producing such a large injection-molded part was an absolute first,” said Xavier Nast, Development Manager for Effbe France. “But everyone approached the project with a high sense of responsibility, and all the partners involved in the project did an excellent job.”

Sealing systems made of liquid silicone

One of the exceptional properties of liquid silicone is its high heat stability. This made it an excellent candidate for this application considering what the heat shield gaskets have to withstand on the two vernier rockets on the Ariane 5. The two vernier rockets attached to the sides, thus also known as “strap-on boosters,” support the two-stage carrier rocket at the start. Each of these reusable strap-on boosters is more than 31 meters tall and has a diameter of three meters; each develops thrust at launch of 536 tons. After a burn phase lasting almost two minutes, they detach and descend to earth on parachutes, where they are then recovered from the Atlantic. In this context, the heat shield gaskets serve to protect the elastic rubber joints on the pipe conduits of the Ariane 5 rocket engines against the extreme heat that develops. The gaskets can withstand temperatures of up to 3000ºC and heights of up to 40000meters for a period of two minutes. The main function of these sleeves is to maintain their extreme sealing properties under enormous stress and strain.

Production-ready in just six months

To include the comprehensive material and tool-making know-how at Woco Group, the Woco expert center for LSR in Boxberg was integrated into the project. This center is closely networked with the materials specialists at Momentive. This allowed the experience that Woco has earned in developing and manufacturing seals and gaskets for household appliances to be harnessed for the project. Initial tests were conducted with a tool used for washing machine collar gaskets. From this point, the team developed two injection molds of different sizes to be used for production of the enormous gaskets in a complex procedure. Even manufacturing the tools was a very unique challenge. The heat shield gaskets were ready for series production in just six months, and they have been in production at Effbe in Habsheim ever since.

Woco Group – Business Overview

The globally active Woco Group, with its headquarters located in Bad Soden-Salmünster, is a family-run company that achieved a turnover of 670 million euros with 4,800 employees in 2006. In automotive engineering, Woco offers comprehensive solutions in the sector of vibration and noise reduction as well as actuators and seals. With its products, Woco improves comfort and security for the automobile, on a perceptible and audible level, and makes a contribution to protecting the environment by decreasing noise and increasing fuel economy. The group sells high-quality products and functional solutions for various applications in the industry such as household appliances, measuring and control systems and pipeline systems. For more information, please visit www.wocogroup.com .

Momentive Performance Materials – Business Overview

Momentive Performance Materials was created from the sale of GE Advanced Materials and its former Joint Ventures GE Bayer Silicones and GE Toshiba Silicones to Apollo Management, L.P. in December 2006. Momentive is the world’s second-largest producer of silicones and silicone derivatives and a global leader in the development and manufacture of products derived from quartz and advanced ceramics. Silicones are a multi-functional family of materials used in thousands of products and serve as a critical ingredient in many construction, transportation, personal care, electronic, consumer and agricultural uses. Silicones are generally used as an additive to a wide variety of end-use products in order to provide or enhance certain of their attributes, such as resistance (heat, ultraviolet light and chemical), lubrication, adhesion or viscosity. Some of the most well-known end-use product applications include bath and shower caulk, pressure sensitive adhesive labels, foam products, cosmetics and tires. Our Quartz division manufactures quartz, specialty ceramics and crystal products for use in a number of high-technology industries, which typically require products made to precise specifications.

These materials solutions are used as springboards for innovation in hundreds of consumer and industrial applications ranging from car engines to biomedical devices to integrated circuits. Industries served include aerospace, agriculture, appliances, automotive, construction, electronics, furniture and furnishings, healthcare, home care, industrial, lighting, packaging, personal care, plastics, semiconductor, telecommunications, tire, transportation, and water purification.

World Headquarters: Wilton, Connecticut

President & CEO: Jonathan Rich

Number of Employees: Approximately 5,000

Revenue in 2006: $2.5 Billion

Website information available under: www.momentive.com

Reader enquiries

Momentive Performance Materials
Chempark Leverkusen
51368 Leverkusen
Germany
Central European Customer Service: cs-eur.silicones@momentive.com
Toll free telephone: 0080043211000

+31 (0) 164 225 350

www.momentive.com