Seals

Dipl.-Ing. Thorsten Sattler-Lägel
29.09.2023

Seals - Customized
according to your ideas.

Seals, these at first glance inconspicuous components, are our focus. Because without a perfect seal, the most elegant component and the most careful installation are of no use.

Thus, a supposedly insignificant component quickly becomes a decisive product to which we pay the utmost attention.

Whether in mechanical engineering or vehicle construction, in plant engineering or sanitary installation - the areas of application for seals are so varied that great importance must be attached to form and material selection.

That's why we support you in your project with custom-made seals made of materials that are optimally suited to your project.

What are seals for?

Seals are workpieces that connect the various components of a structure in such a way that it is sealed against gases or liquids.

If, for example, a faucet drips in the bathroom or the footwell in the car is damp, the cause is usually to be found in a defective seal.

Here, seals can reliably seal static elements and elements that move against each other under the most difficult conditions.

The sealing material is therefore as diverse as the application of seals. We match this material optimally to the respective customer requirement and guarantee the highest possible quality for the material and manufacturing processes of our products.

What are gaskets made of?

We supply customized seals made of high-tech materials according to customer requirements. High-quality elastomers are used, which are specially selected and optimized for the respective application. These include polymers such as:

  • EPDM ( ethylene propylene diene rubber)

  • NBR, HNBR (nitrile butadiene rubber or hydrogenated nitrile rubber)

  • MVQ, VMQ (silicone rubber)

  • Natural rubber

EPDM ( ethylene propylene diene rubber) is obtained by refining natural rubber and is characterized by great weather and ozone resistance and high elasticity. EPDM is very suitable for seals that come into contact with hot steam and water.

The polymer is less resistant to mineral oils and fuels. EPDM is suitable for the production of O-rings in mechanical seals or also flat seals.

NBR, HNBR (nitrile butadiene rubber or hydrogenated nitrile rubber) is a polymer with high resistance to oils, greases and hydrocarbons. The material is characterized by low aging behavior as well as abrasion. By varying the acrylonitrile content during synthesis, NBR and HNBR can be influenced in terms of swelling resistance, elasticity, low-temperature flexibility and gas permeability. NBR is physiologically harmless and is therefore also used in the food industry.

MVQ, VMQ (silicone rubber) is non-toxic highly elastic plastic based on silicon, which can be used to produce much more than the well-known sealant for sanitary installations. Silicone rubber is highly resistant to temperature and is also food safe.

Natural rubber is an inexpensive and very durable product. It can be varied in hardness through different chemical treatments. However, natural rubber can dissolve when exposed to UV light or intense contact with grease. Natural rubber can be provided with various additives and is also available in food-grade quality.

What are the types of gaskets?

According to their different application purposes, gaskets can be divided into different types. According to the type of sealing effects, contact seals and non-contact seals can be distinguished from each other.

Contact seals consist of an elastic material that connects two static or dynamic components in a gas- and liquid-tight manner. Non-contact seals are generally used on dynamic components. Examples of non-contact seals are pressure and throttle seals, mass-force seals or viscous seals.

Based on the relative movement of the components to be sealed, a distinction is also made between static and dynamic seals.

Static seals

Static seals are usually designed as contact seals and do not perform any movements themselves. Rather, they serve to reliably compensate for the relative movements of the adjacent workpieces in such a way that no gas or liquid exchange with the environment can be observed.

The following basic forms are used as static gaskets:

  • Flat gaskets are made from a variety of materials and are used primarily in pipeline and apparatus construction.
  • Profile gaskets owe their name to their distinctive cross-sectional profile and are becoming increasingly important in thermal insulation.
  • Socket gaskets facilitate the transition between different pipe diameters.
  • Rolled gaskets are made from a variety of heavy-duty materials.

Dynamic seals

A dynamic seal also connects two elements, but carries out movements itself. These movements can be of a translational nature, i.e. force-transmitting along an axis, or of a rotational nature, around a central axis.

Dynamic seals are used for a wide variety of purposes. This type of seal includes such products as bellows or brush seals.

  • A stuffing box seals a rotating shaft against the leakage of lubricant and against the effects of dirt and water vapor.
  • Piston rings are important sealing elements in the combustion chamber of an engine that have to withstand the highest loads.
  • Many customers are familiar with bellows from buses and trains. We supply bellows in almost all dimensions from large to small. A bellows protects moving machine parts from dirt and moisture.
  • A brush seal consists of a bundle of thousands of fibers that lie tightly against the surface to be sealed. Brush seals are increasingly used in engines and turbines, where they have replaced the labyrinth seals that were frequently used until then. Brush seals have a very low leakage rate.
  • Hydraulic seals are used in hydraulic cylinders, where they prevent leakage of the hydraulic fluid and at the same time allow smooth translatory stroke movement of the piston.
  • A similar task is performed by the pneumatic seal, which effectively prevents the loss of compressed air in pneumatic systems while allowing proper clearance of the pneumatic piston.
  • A carbon lamella, also known as a carbon separator, separates the rotor from the housing chamber in pumps and compressors. Carbon has proven itself here as a low-wear material with an excellent coefficient of friction.

Non-contact seals

Non-contact seals are mainly used as dynamic seals when it is necessary that a small gap cross-sintt remains between the seal and the machine part. The sealing effect of a non-contact seal is therefore never perfect due to its design.

Small quantities of lubricants and operating fluids can always escape through the gap between the seal and the component. A non-contact seal must therefore be designed in such a way that it enables the greatest possible sealing effect with the smallest possible obstruction to movement.

A distinction is made between the following types of seals:

  • Pressure and throttle seals - such as labyrinth and chamber seals
  • Mass-force seals - such as flinger discs and splash rings
  • Viscous seals - in this case mainly shaft seals

Which material is suitable for which seal?

The materials from which gaskets are made are as varied as their types and areas of application.

In addition to low wear and a favorable coefficient of friction, factors such as operating temperature and contact with operating materials also play a major role in selecting the optimum production material.

For the production of a perfect seal, it is therefore important that you inform us of the intended use. This enables us to select the right gasket material for your optimally designed product. For this purpose, we have a large selection of high-quality polymers with a wide range of physical, chemical and mechanical properties.

What are the areas of application for gaskets?

The areas of application for our products are as varied as the sealing materials. For example, you will find seals in the construction industry for doors and windows as well as in the sanitary sector, in automotive and mechanical engineering as well as in the chemical and food industry.

Seals in the sanitary area

What would taps, siphons, showers and bathtubs be without seals? If you don't want to experience any nasty surprises due to water damage, you should rely on high-quality seals in the sanitary area.

Seals for windows & doors

No house or apartment is rented without an energy certificate. Improperly sealed windows and doors are the biggest cold bridge. Perfect window seals save money and enhance the energy efficiency of any property.

Seals in the automotive sector

From door seals to piston rings, every vehicle needs gaskets in large numbers and different designs. Due to contact with lubricants and fuels, they place high demands on materials and are also exposed to wind and weather.

Seals in mechanical engineering

Both static and dynamic seals are used in mechanical engineering. In addition to pipeline construction, hydraulics and pneumatics are inconceivable without high-quality seals.

Seals in industry

Seals used in industrial applications have to meet the most stringent requirements in terms of wear resistance. Since large forces act on them over a long period of time, the dimensional stability and abrasion resistance of the sealants used are of primary importance in addition to the sealing effect.

Seals in the chemical and food industries

Seals for the chemical and food industries have special requirements in terms of the sealing materials that can be used. Depending on the processes used, sealants with high chemical resistance are required in the chemical industry.

For example, seals that are not resistant to mineral oil are not used in the petrochemical industry.

In the food processing industry, only seals made of non-toxic and food-safe sealing materials may be used. As a rule, these are various silicones.

How to get your gasket

Price, quality, delivery reliability, and cost-effectiveness are also essential factors for the supply of sealing elements. When it comes to the exact manufacture and delivery of components according to your drawings, samples or plans, there is another indispensable factor: expertise.

With many years of experience in processing elastomers and high-performance plastics, as well as numerous customers in almost every industry, it is easy for us to keep track of the entire process for which you need your seals.

Therefore, solutions often come up during the planning of your product, where we could help our customers with specific improvements in details.

Approach us with a drawing or your own prototypes. Together, we will make the selection for the perfect gasket material and create for you the exact gasket that fits your application.

Literature Sources:

Streit, Gerhard et al: Elastomer sealing systems - materials, applications, designs, standards. Expert-Verlag 2010, ISBN 9783816928959
Tietze, Wolfgang: Handbook of Sealing Practice. Vulkan-Verlag GmbH 2003, ISBN 9783802733017

Dipl.-Ing. Thorsten Sattler-Lägel

As Managing Director of Sattler GmbH, it is a constant concern of mine to meet our customers not only as a trading partner, but also as a competent procurement service provider for applications in the plastics and rubber sector. I am an engineer by heart and most passionate when I can solve detailed technical issues to create sophisticated, customized solutions.

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