Articles

RSS

At Interphex 2006, DuPont Performance Elastomers will showcase FDA compliant Viton® GF-600S and Viton® Extreme™ ETP-600S — the latest specialty types of Viton® fluoroelastomers (FKM) for critical pharmaceutical, food and beverage process sealing — providing steam resistance superior to silicone, better caustic cleaning fluid resistance vs EPDM and bisphenol-cured FKM, and low total organic carbon and metal extractables similar to PTFE. The latest Viton® types are made with Advanced Polymer Architecture (APA), a proprietary development by the company that improves the performance of specialty fluoroelastomers.

Viton® GF-600S is a high-fluorine, peroxide-cure type of fluoroelastomer that exhibits superior resistance to steam and to a much wider variety of cleaning fluids than older bisphenol-cured FKM, and also offers excellent physical properties, including resistance to compression set. FDA repeat use food contact compliance with limitations/specifications for Vitonâ GF-600S is outlined in Food Contact Notification (FCN) 510*.

Viton® Extreme™ ETP-600S is a unique fluoroelastomer that exhibits excellent resistance to steam and to attack by an exceptionally broad variety of chemicals and fluids, including aliphatic and aromatic hydrocarbons, acids, bases, all types of alcohols and even low molecular weight ketones, esters, and aldehydes. FDA repeat use food contact compliance with limitations/specifications for Vitonâ Extreme™ ETP-600S is outlined in Food Contact Notification (FCN) 539*.

Comparative laboratory test results have shown Viton® GF-600S and Viton® Extreme™ ETP-600S provide:

• Improved resistance to steam and caustic cleaning fluids vs bisphenol-cured FKM.
  
• Superior steam resistance compared to silicone.
  
• Better resistance to caustic cleaning fluids than EPDM.
  
• Significantly lower total organic carbon and metal extractables compared to EPDM and silicone.
  
• Sealing capability up to 200°C in continuous service, and at higher temperatures for short-term excursions.

The new level of sealing performance claimed for Viton® GF-600S and Viton® Extreme™ ETP-600S is based on comparative laboratory tests by DuPont Performance Elastomers on seals made with EPDM, platinum-cured silicone, bisphenol-cured FKM, and PTFE, obtained from a commercial supplier of seals used in the food and pharmaceutical industry (see Figure 1. Relative Performance of Elastomer Sealing Materials).

Sterilization processes used by pharmaceutical, food and beverage manufacturers frequently use steam or caustic chemicals or a combination of both. These aggressive conditions put special demands on commonly used sealing materials such as EPDM, silicone, PTFE and bisphenol-cured FKM. EPDM is capable of providing excellent steam resistance, but exhibits relatively poor resistance to some commonly used cleaning fluids. Seals made with silicone may provide good resistance to a wide variety of cleaning fluids, but have relatively poor steam resistance. PTFE seals offer excellent resistance to steam and chemical attack, but, because of their plastic nature, can creep under stress. Bisphenol-cured FKM has good steam resistance but is less resistant to some caustic sterilization processes.

SOURCE: DuPont Performance Elastomers