º£½ÇÖ±²¥ Results

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
  Selected EPDM materials 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.
• FKM
  The standard FKM material shows good performance in acidic fluids with active oxygen and unpolar solvents, however, its exposure time to steam should be limited. A premium FKM compound 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.
• ±õ²õ´Ç±ô²¹²õ³Ù®
  ±õ²õ´Ç±ô²¹²õ³Ù® 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 ±õ²õ´Ç±ô²¹²õ³Ù® should be selected for the most critical applications where line stops cannot be tolerated.
• °Õ³Ü°ù³¦´Ç²Ô®
  °Õ³Ü°ù³¦´Ç²Ô® 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 °Õ³Ü°ù³¦´Ç²Ô® MF range of materials has been specially developed for aseptic applications, with compliance to most major standards.

Find out more about FoodPro^® materials

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

Linear Hydraulic Seals

A leader in fluid sealing.

At the forefront of product design for fluid sealing situations, Trelleborg Sealing Solutions provides an unrivalled range of proprietary seals for dynamic linear applications. Our range of products is one of the broadest on the market, satisfying specific needs.

°Õ³Ü°ù³¦´Ç²Ô® Glyd Ring® with improved leakage control
 and  give excellent leakage control in piston and rod applications along with resistance to extrusion.

These double acting O-Ring energized seals are primarily for dynamic applications where they give high wear resistance. Their low friction characteristics give long life and prevent sticking even after extended periods of rest. Typical applications are high performance piston fillers and metering pumps for very viscous fluids.

°Õ³Ü°ù³¦´Ç²Ô® Stepseal® enhances performance in cylinder applications

Achieving new levels in piston and rod sealing, the  enhances efficiency in these applications.

With excellent extrusion resistance, it gives superior leakage control. It also has uniform, low friction characteristics throughout an extended life, and sticking is prevented, even after long periods of rest. With very good abrasion resistance, this seal is a good choice for sticky fluids such as syrups and in glues.

°Õ³Ü°ù³¦´Ç²Ô® Variseal® for optimum aseptic sealing

 is an extremely important product within bioprocessing, food, beverage and pharmaceutical production. Commonly installed in filling plants, where demands are high on cleanability, sterilization and hygienic design, it is field proven in such operating conditions. Designed to fit in existing O-Ring grooves, it can provide a very high level of integrity, even in aggressive system media and within cleaning regimes.

For static and dynamic applications, these seals demonstrate low-friction characteristics, leading to extended service life.

In addition to these seals, the fluid sealing range also includes the products , , , , T,  and 

Rotary Seals

Specialized high performance rotary sealing products

When it comes to successfully sealing in rotary applications, specialized products are required. Trelleborg Sealing Solutions offers a range of unique options, both standard and custom, that give exceptional performance characteristics in demanding rotary situations.

• , with its V shaped ring, has a flanged heel which prevents the seal from rotating in the groove.
•  is double acting and suitable for rotating, oscillating and helically moving pistons, rods and shafts.

rotary shaft seals are constructed from one or multiple °Õ³Ü°ù³¦´Ç²Ô® PTFE based sealing elements which are mechanically retained in a precision machined metal body. The °Õ³Ü°ù³¦´Ç²Ô® sealing element provides positive dynamic sealing on the shaft, while the metal body gives a robust static seal against the housing, performing effectively at high rotary speeds. Characterized by low friction and stick-slip-free running, the seal reduces temperature generation, permits higher peripheral speeds and lowers power consumption. This results in a long-service life, with maximized mean time between planned maintenance and greater productivity.

Coating Technology 

Surface treatment to improve friction characteristics

Elastomers have a high coefficient of friction. This means they tend to stick, either to each other during automated assembly, or to mating surfaces when inserted into a housing. Coating technology improves the friction characteristics of elastomer seals, enhances wear resistance, lowers insertion forces and, thereby, supports sealing in some dynamic applications.

Ideal for automated assembly

The coating is suited for all kinds of elastomer seals, depending on their shape and size, and does not affect the seal’s natural elasticity. Its reduced friction makes it ideal in automated assembly processes. Suited for both static and low-level dynamic applications, with infrequent movement and short stroke rate, it retains its properties in repeated insertion and dismantling processes.

Applications:

• Plug-in couplings or quick-release couplings
• Seals inside valves
• Any kind of automated or manual assembly

Seal-Glide® Medical modification for minimized friction in food and beverage processing

Trelleborg Sealing Solutions Seal-Glide® Medical coating technology is suitable for use in food contact applications. Seal-Glide® characteristics are:

• Reduces assembly forces
• Prevents parts from sticking together 
• Improves automatic supply
• Extends the use in dynamic applications
• Extends service life due to better wear properties and increased assembly safety
• Highly chemical resistant
• Products can be sterilized (SIP/CIP)
• Compliant with FDA 175.300 and Reg (EC) 1935/2004

FlexCoat FF coating for food contact applications
Trelleborg Sealing Solutions FF coating is the ideal surface treatment for food and beverage processing. Its characteristics are:

• Compliant with FDA 178.3570 (Lubricants with incidental food contact) and Reg (EC) 1935/2004
• Water based, solvent-free and transparent
• Operating temperature of -40ºC / -40ºF to 150ºC / 302ºF

Silicone and Liquid Silicone Rubber

Silicone inherently inert to growth of bacteria, mold and fungi

Silicone materials are ideal for use in food and beverage production due to their inherent inertness to growth of bacteria, mold and fungi.

Advantages of silicone:

• Excellent heat resistance, cold flexibility and dielectric properties
• Preferred choice in applications exposed to ozone and oxygen 
• Operating temperature from -60°C to +200°C / -76°F to +392°F
• Exceptionally low surface energy, seals will not adhere to counterparts.
• Low long-term compression set
• Suitable for use with hot water, fat and oil, some lubricants and glycerin.

A possible limitation of silicone is that chemical degradation can occur in contact with acids, alkalis, ketones, esters and steam above 100°C / 212°F.