SOURCE: Trelleborg Sealing Solutions

November 19, 2007 08:00 ET

Keeping Up With the Grind: Trelleborg Sealing Solutions Supplies Seals for World Leading Manufacturer WMF Professional Coffee Machines

Specially Modified Stepseal® in Turcon® MF Creates a Piston Seal That Stands Up to Brewing Over 100,000 Cups of Coffee

FORT WAYNE, IN--(Marketwire - November 19, 2007) - You cannot compare the professional coffee machines manufactured by WMF to those found in the average home. Their machines are engineered to brew up to 300 cups of coffee per hour. That means each component must be of the highest quality and durability. In WMF coffee machines, the standard non-abrasive plastic internal parts of domestic models are replaced with metal, and the demands on seals within these are high.

In the WMF bistro range of machines, coffee is freshly ground. A piston presses these grounds into a cylinder, at the bottom of which is a metal sieve. To make the coffee, boiling water is jetted through the cylinder, where the seal is located, with a 2.7 inch/70 mm stroke of the piston at a pressure of 232 psi/16 bar. The sieve then swings down and the piston pushes the used coffee grounds out of the cylinder into a collecting tray. This process is repeated for every single cup of coffee, up to 300 times per hour.

Seals in these coffee machines need to have excellent friction characteristics for movement against the equipment's hard metal counter surfaces, along with exceptional wear resistance to withstand abrasion from ground coffee beans. They must be compatible with process media including acids in coffee, fats in milk and the aggressive chemicals in cleaning regimes. In addition, pressures are high as the boiling water is forced through the coffee grounds.

The sealing solution proposed to WMF by Trelleborg Sealing Solutions was a modified Stepseal® design, its unique geometry engineered to endure the specific requirements of this intensely dynamic environment. Turcon® MF, a proprietary PTFE-based material was chosen for the seal, a compound specifically formulated for food, beverage and pharmaceutical processing.

Based on ultra-clean technology, Turcon® MF compounds are manufactured from high-purity PTFE grades and additives. Their smooth finish, with high gloss and low porosity, avoids the risk of contamination buildup and reduces particle shedding. Capable of operating in the high temperatures and process media of the brewing environment, its excellent friction characteristics further enhance the seal's capabilities in this dynamic situation. It is also compliant to FDA 21 CFR177.1550, 3-A and USP Class VI.

The modified Stepseal® manufactured in Turcon® MF is proving to provide extended life in this harsh processing environment, meeting WMF's target of a product that will stand up to brewing at least 100,000 cups of coffee.

Turcon® MF features and benefits:

--  Temperature resistance from -423°F to 500°F/-253°C to +260°C
--  Almost universal chemical compatibility
--  Outstanding low long-term compression set characteristics
--  High-wear resistance
--  Minimal creep and permeation
--  Surface finish minimizes contamination risk
--  Materials perform well in a broad range of chemical media including
    organic and inorganic oxides, acids, alkalis, amines, esters and steam
--  Materials compliant to FDA 21 CFR177.1550, 3-A, USP Class VI and
    sanitary standards

Trelleborg Sealing Solutions, formerly known as Busak+Shamban, is one of the world's leading developers, manufacturers and suppliers of precision seals. They support their aerospace, industrial and automotive customers through 30 production facilities and more than 40 marketing companies globally. Within their portfolio are some of the longest established sealing brands, including Chase Walton, Dowty, Forsheda, Palmer Chenard, Shamban, Skeg, and Stefa along with a large number of proprietary products and materials such as Turcon®, Zurcon®, Orkot®, Isolast®, Stepseal®, and Wills Rings®.

Trelleborg is a global industrial group whose leading positions are based on advanced polymer technology and in-depth applications know-how. Trelleborg develops high-performance solutions that seal, damp and protect in demanding industrial environments. The Trelleborg Group has annual sales of approximately $4 billion, with about 23,000 employees in 40 countries. The Group is comprised of four business areas: Trelleborg Engineered Systems, Trelleborg Automotive, Trelleborg Sealing Solutions and Trelleborg Wheel Systems.

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