Gaskets in NBR: types and applications

Elastomer gaskets offer an essential solution in many industrial applications, due to the interesting characteristics of elastomers. They stand out for their resistance to chemical stress, but also for their ability to deform under stress and then regain their original shape once the source of stress is removed, offering superior elasticity and resistance.

It is not hard to imagine how these properties render them ideal for guaranteeing durability, flexibility and excellent performance, even under complex operating conditions. NBR, in particular, is a synthetic material that has revolutionised the gasket sector: with its excellent compatibility with substances such as oils, hydrocarbons and hydraulic fluids, it now plays an essential role in numerous sectors.

What exactly is NBR? Why and when should it be chosen for your gaskets?

NBR material: what is it and what are its properties?

NBR (Nitrile Butadiene Rubber), or nitrile rubber, is a synthetic elastomer popular for its mechanical properties and for its resistance to deformation. It is chemically compatible with oily substances (animal, mineral and vegetable), fuels, hydrocarbons and sea water. It also offers good compatibility with a range of hydraulic fluids, as well as Freon, concentrated alkaline solutions and alcohols, and also performs well in contact with diluted acid solutions and diester-based lubricants.

This rubber offers a combination of flexibility, resistance to abrasion and durability, rendering it ideal for a wide range of industrial purposes. With its operating temperature range, it is versatile in environments characterised by changes in temperature: it is resistant at a minimum of -15/-30°C (-40°C with custom formulations) and up to a maximum of +100/+110°C (+130°C with dedicated formulations).

However, standard NBR is less resistant to strong mineral acids or to hot diluted alkaline solutions, as well as to ketones, esters, benzene, phenol, certain brake fluids and some hydraulic fluids. Furthermore, it offers poor resistance to atmospheric agents, such as ozone and UV radiation, requiring special treatment or alternatives for specific applications.

Main applications for gaskets in NBR

Seals made with NBR are widely used in critical sectors, thanks to their capacity to maintain a seal even under stress and in the presence of chemical substances typically used in these sectors.

In the automotive industry they are used in engines, transmissions and braking systems, guaranteeing a secure and lasting seal.
In the mechanical industry they are used to seal machinery subject to mechanical and chemical stress.
In hydraulic systems they play an essential role in resisting pressurised fluids and preventing leaks in hydraulic circuits.
In pneumatic applications they are ideal for guaranteeing a reliable seal in the presence of gas or compressed air mixtures.

NBR and the food processing sector: a change in legislation

In the past, NBR was also used in a range of food-processing applications thanks to its chemical resistance and versatility. However, recent European and international legislation has introduced more stringent criteria regarding materials in contact with food, imposing the absence of potential migratables, i.e., chemical substances that may transfer from material to food, contaminating the latter.

Standard NBR material may contain certain chemical components, such as plasticisers or additives, which are no longer compliant with these new directives. This is why the use of NBR in the food-processing sector has been gradually reduced.

However, there are certain variants of NBR that are specifically formulated and certified, and which can be used in determined food-processing applications. Nevertheless, these variants are less common than other safer and currently widespread alternatives, such as food-grade EPDM, silicone and FKM, which are designed to guarantee high levels of safety and performance, and are accompanied by specific certification guaranteeing their suitability for contact with food.

Customisation: the made-to-measure services of GB Group

Our experience means that we are able to recommend the best solution for you for every application. Furthermore, one of the strengths of GB Group is its ability to produce custom gaskets and other items, taking advantage of a production process that can be fully modulated to suit your specific demands. How do we operate?

Technical analysis: we assess the specifics of the application in order to choose the most suitable material and design.
Design: we use advanced software and the expertise of our technicians to create custom solutions.
In-house production: we monitor every single phase of production, from prototyping to final manufacturing.
Certification: we can guarantee that the final product respects the legislation applicable to your sector.

Our gaskets in NBR represent a combination of quality and reliability, thanks to the use of high-standard materials and stringent monitoring of all phases of production. Furthermore, the specialised skills of our collaborators allows us to offer suitable alternatives for any requirement, including those of the most sensitive sectors, such as food processing.

If you need custom gaskets, or want to explore the properties of NBR for your application, the team at GB Group is on hand to offer you technical support and professional consultancy.