Tests prove that matching seal material to an application can extend seal life

Specifying the right seal material when CIP and SIP is used is not a simple matter and standards do not really help. They only offer general information and refer just to groups of elastomeric materials and their compliance with standards. This is why Trelleborg Sealing Solutions has undertaken their own tests to support customers in recommending the optimum sealing material for specific applications.

Material Compatibility tests in CIP and SIP media

Comprehensive studies undertaken by Trelleborg Sealing Solutions have evaluated the performance of materials in a wide range of commercially available and commonly used CIP fluids and solvents. As the CIP process is now usually followed by sterilization in superheated steam up to 150°C / 302°F, tests were also carried out in these conditions.

The most important properties, such as:

• Volume Change
• Weight Change
• Change of Elongation at break
• Change of Tensile Strength
• Hardness Change

Recommendations based on results

As expected, the intensive CIP fluids and high temperatures brought some elastomers tested to their performance limits. Importantly though, results from different materials, even within the same family of basic polymers, were vastly different. This has allowed Trelleborg Sealing Solutions to engineer materials that give maximized performance in CIP and SIP regimes.

Overall conclusions:

• EPDM
  EPDM materials E7502, E7518 and E8502 displayed excellent results in most CIP fluids and superheated steam. Tests proved that these grades can be used with aggressive polar solvents such as Acetone and Methyl-Ethyl-Ketone (MEK). Due to the unpolar nature of EPDM, they are not recommended for extremely fatty foods and some food grade lubricants.
  Find out more about EPDM
• FKM
  The standard V8605 shows good performance in acidic fluids with active oxygen and unpolar solvents, however, its exposure time to steam should be limited. The premium FKM V8T41 can be exposed to steam up to 170°C/338°F and is also more resistant to all types of cleaning fluids. Seals of this material provide longer life than standard FKM seals. Both are high polar compounds and can be used in fatty foods, cosmetics, oils and lubricants.
  Find out more about FKM
• Resifluor™ 500
  Its unique polymer architecture means Resifluor™ 500 can be used with both polar and unpolar fluids, all CIP media and in superheated steam. It also displayed excellent properties in solvents such as MEK, Toluene and Acetone. The fact that Resifluor™ 500 has the combined characteristics of an EPDM and high fluorinated FKM makes it ideal for mixed process streams.
  Find out more about Resifluor™ 500
• Isolast®
  Isolast® FFKM gave the best performance in all test situations. In addition, it has been proved in steam at temperatures up to 240°C/464°F. This means that Isolast® should be selected for the most critical applications where line stops cannot be tolerated.
  Find out more about Isolast®
• Turcon®
  Turcon® PTFE based sealing materials have almost universal chemical compatibility and are capable of operating at high temperatures and in steam. This makes them ideal for use in CIP and SIP regimes. The Turcon® MF range of materials has been specially developed for aseptic applications, with compliance to most major standards.
  Find out more about Turcon®

CIP and SIP test results

The table below provides an easy overview of the performance of the Trelleborg Sealing Solutions material portfolio in test conditions.

To obtain the best recommendation for a specific application, please contact your local Trelleborg Sealing Solutions marketing company. Go to contact list

Choosing the right material to extend life

Although standard immersion tests provide detailed information about the suitability of materials in certain fluids, they are not very helpful in predicting length of life of sealing materials. This is why Trelleborg Sealing Solutions has extended our testing over a wider range of temperatures, high concentrations of chemicals and longer immersion times.

In the first test, a variety of FKM materials were tested at two different temperatures. At the lower one, all compounds showed good results. However, it was not until the test was repeated at a higher temperature that the differences between the material characteristics became clear. In the second test, the concentration of CIP medias was changed from 1% to 2%. Again, the differences only became apparent in the more demanding conditions.

By undertaking these more extensive tests, Trelleborg Sealing Solutions can recommend seals that:

• Provide extended life
• Minimize maintenance cost
• Reduce life time cycle costs