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Great Climate

Sealing Solutions for Building Engineering

Our product range for use in heating, ventilation and air-conditioning technology – the technical term is HVAC – is designed for high energy efficiency and longevity. The distinguishing features of our seals, diaphragms, O-rings and our customer-specific molded parts are their high temperature resistance and their resistance to a wide range of chemicals and refrigerants.

For example, spring-loaded PTFE seals for compressors, PTFE and solenoid piston seals for HVAC valves and silicone diaphragms for pressure and changeover valves in heating systems are very popular among our customers in the HVAC segment.

Dispersed Fiber Speaker Surrounds: Enhancing Your Speaker Experience

How a Speaker Works: A Quick Overview

A speaker functions by transforming electrical energy into mechanical energy, which compresses air and converts the motion into sound energy or sound pressure level. Most speakers are comprised of permanent magnets, voice coils, bobbins, spiders or suspensions, cones or diaphragms, dust caps, speaker baskets, surrounds, speaker terminals, and braided wires that all work together to produce sound.

Why Speaker Surrounds Matter

The speaker surround is a critical component in the quality and consistency of the listener's enjoyment. Typically, they are composed of flexible materials like foam, rubber, or synthetic polymer, designed to absorb and dissipate vibrations generated by the speaker cone's movement. When the speaker cone moves back and forth, it creates pressure waves that travel through the air and into our ears, but this movement also generates vibrations that can cause unwanted resonances and distortions.

The speaker surround functions as a suspension component, flexing and deforming as the speaker cone moves back and forth, absorbing some of the energy of the vibrations. The damping effect of the surround is intended to reduce unwanted resonances and distortions, resulting in a cleaner and more accurate sound regardless of environment.

Different materials and designs can be utilized for speaker surrounds, each with its own unique properties and characteristics. The choice of surround material and design will depend on factors such as the intended use of the speaker and desired sound quality.

The Impact of Freudenberg Speaker Surrounds on the Listening Experience

Freudenberg uses a combination of material technology expertise, dynamic mechanical analysis, and precision manufacturing to develop the optimal damping material and mold the speaker surround to exacting tolerances to enhance the listening experience.

Freudenberg's speaker surrounds incorporate Dispersed Fiber Technology (DFT), which provides reinforcement for rubber speaker surrounds during high-volume moments, reducing localized strain on the surround and contributing to less perceived noise distortion. Thanks to DFT, Freudenberg speaker surrounds offer exceptional damping effects that do not compromise quality whether the listener is indoors or outdoors.

All in Flow

Whether it’s fresh water, waste water, heating water or gas – flow and pressure must be precisely controlled in buildings. This requires seals made of materials that are not only water and gas resistant, but also have very good compression and permeation properties: in fittings, control and safety valves, pipes and thermostats.

Fabric or Dispersed Fiber Technology (DFT) reinforced membranes from Freudenberg are the first choice for gas regulators and meters. Here too, the basis is formed by material mixtures that allow for customer-specific and legal requirements to be met.

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Arrive Faster

Sealing solutions from Freudenberg Sealing Technologies help people and goods reach their destination safely, not only in cars, trucks, buses, trains, aircraft and ships.

Customized sealing technology from Freudenberg also ensures fast and convenient progress inside buildings: in elevators in high-rise buildings, on escalators in shopping centers, on moving walkways in airports.

In the Kitchen and Bathroom at Home

The kitchen is a get-together place; the bathroom is the place for relaxed body care and hygiene. Fittings serve as functional style elements in both places. Right in the middle: Seals and components from Freudenberg Sealing Technologies – in shower heads, fittings for washbasins, sinks and bathtubs, including their cartridges, in thermostats, toilet flushes and much more.

Their advantages in a nutshell: excellent temperature resistance to cold and hot water; application-specific surface properties for a long service life; resource-saving design for economical water consumption.

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Material Know-How - The Right Mix

In drinking water and gas applications, materials are subject to diverse norms and regulations. We have made it our business to develop materials in accordance with the latest requirements, e.g. the new version of the KTW-certification for elastomers used in drinking water applications or regionally distinct legislative directives covering elastomers in gas applications.

Working with all key associations and having a unique know-how in elastomer-related production processes and material sciences, FST is able to provide friction- and weight-optimized solutions to its customers, helping them to meet the current and future energy saving requirements for their applications, e.g. for solar thermal collectors, heat pumps or air conditioners.

Modern air conditioner are driven by compressors boosting a high-pressure gas from low-pressure gas. This power conversion requires unique material expertise. Material compatibility and long lasting seal designs will ensure energy efficiency and longer service life. Choosing the right material is of great essence to the success of your HVAC application. Freudenberg-Sealing Technologies is the right partner with dedicated advance engineered plastics and elastomers for your application. We have developed a range of materials including, NBR, CR, EPDM, ECO, FKM, FFKM, FVMQ, HNBR, SBR and flame retardant rubbers to fulfill specific requirements for products within the building engineering applications.

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Many people know Polytetrafluoroethylene (PTFE) as a non-stick coating for pots and pans in households. The plastic is also highly interesting as a sealing material in building technology because it proves to be resistant to chemical attacks. Beyond this media resistance, the physiologically harmless PTFE can be used in a wide temperature range and convinces with its low friction.

Freudenberg Sealing Technologies has developed PTFE seals in individual designs for building technology especially for refrigeration solenoid valves and compressors.

A light blue and dark blue membrane on white background


Freudenberg Sealing Technologies has the technical expertise and materials know-how to supply the optimal diaphragm for every application: in pumps, actuators, hydraulic accumulators, valves and controllers; both in standardized and customer-specific sizes and designs.

Silicone diaphragms are used in gas valves for hot water preparation and gas dryers, but also in air pressure switches for heating stoves. Fabric or Dispersed Fiber Technology (DFT) reinforced diaphragms are the products of choice for gas regulators and meters.


The recipe for success of the O-ring is its wide range of applications. Accordingly, Freudenberg Sealing Technologies offers a uniquely wide range of standard parts with fast delivery in all common international dimensions and standards. In addition, there are individually developed special solutions based on several hundred material mixtures.

This also applies to drinking water applications with their particularly strict regulations for environmental and health protection. With our certified compounds, you are on the safe side and comply with NSF61, WRAS, ACS, EG, FDA and other regulations.


Materials: Diversity Through Competence

Our premium materials, developed and produced in-house, are perfectly suited for demanding applications in building technology. Compatible with current and future refrigerants, suitable for drinking water, resistant to high and low temperatures – we have the right material mix for every application.

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