Rubber Density

Density is defined as the ratio of the mass of a given substance to the volume of a given product. In this case, we refer to rubber products, most commonly manufactured from rubber compounds.

Density formula

Density is denoted as ro or rho.

The Greek alphabet letter is: ρ

The density formula is calculated as: ρ = m / V

where m denotes the mass of a given object, and V denotes the volume of that object.

Density unit

Like any physical quantity, density also has several units. The basic density units are:

• kg/m³
• kg/l
• g/cm³

Most commonly, for rubber compounds and especially products made from them, kg/m³ and g/cm³ are used.

Density – Unit conversion

If we need to convert units from kg/m³ to g/cm³, the given value should be divided by 1000. Let us check:

Conversion from kg/m³ to g/cm³

To convert units from kg/m³ to g/cm³, you should:

• Write down the given rho value in kg/m³
• Divide this value by 1000
• Add the unit g/cm³

The standard density of rubber is: 1300 kg/m³.

We divide by 1000 and obtain: 1.3

We add the unit: g/cm³

Simple, isn’t it?

Conversion from g/cm³ to kg/m³

To convert units from g/cm³ to kg/m³, you should:

Write down the given rho value in g/cm³
Multiply this value by 1000
Add the unit kg/m³

The standard density of rubber is: 1.3 g/cm³.

We multiply by 1000 and obtain: 1300

We add the correct unit: kg/m³

Rubber density

Rubber, i.e. natural rubber with the symbol NR, originating from trees found in tropical climates. It occurs as a base component of other rubber compounds:

• NBR – Acrylonitrile-butadiene rubber NBR Density: 1.4 to 1.5 g/cm³
• FKM – Fluoroelastomer FKM Density: 1.9 g/cm³
• FPM – Fluoroelastomer FPM Density: 1.9 g/cm³
• Viton® – Fluoroelastomer Viton® Density: 1.9–2.03 g/cm³
• SBR – Styrene-butadiene rubber SBR Density: 1.1 to 1.6 g/cm³
• NR – Natural rubber NR Density: 1.1 to 1.25 g/cm³
• BR – Butadiene rubber BR Density: 0.95 g/cm³
• IIR – Butyl rubber IIR Density: 1.27 g/cm³
• CIIR – Chlorobutyl rubber CIIR Density: 1.3 g/cm³
• CR – Chloroprene rubber – Neoprene CR Density: 1.1 to 1.37 g/cm³
• Hypalon – Chlorosulfonated polyethylene rubber Hypalon Density: 1.36 g/cm³
• EPDM – Ethylene-propylene-diene rubber EPDM Density: 1.4 to 1.5 g/cm³
• EPM – Ethylene-propylene rubber EPM Density: 0.9 g/cm³
• FVMQ – Fluorosilicone rubber FVMQ Density: 1.45 g/cm³
• HNBR – Hydrogenated nitrile rubber HNBR Density: 1.11 g/cm³
• FFKM – Perfluoroelastomer FFKM Density: 1.9 g/cm³
• FFPM – Perfluoroelastomer FFPM Density: 1.9 g/cm³
• Kalrez® – Perfluoroelastomer FFPM Kalrez® Density: 1.9 g/cm³
• VMQ – Silicone rubber MVQ VMQ Density: 1.16 g/cm³

Rubber granulate Density of products made from rubber granulate may range from 0.2 g/cm³ to 1.15 g/cm³
or other rubber compounds produced on special request.

The density value depends on the type of rubber. We can distinguish three types of rubber in terms of hardness differentiation:

Solid rubber products
Sponge rubber
Rubber products made of granulate

As can be seen, the type of product matters.

Density of rubber and rubber compounds

The density of rubber is 1.2 g/cm³.

Density of rubber products made of rubber granulate

It is worth adding that the density of rubber products made from granulate is variable and depends on:

• Grain size (fraction)
• Intended use
• Type of adhesive used
• Compression time

The density of rubber articles made of rubber granulate is: 460 kg/m³.

Rubber Shore hardness

Another factor that also affects rubber density is its hardness. Depending on the application, the following rule applies:

The greater the hardness, the greater the density of rubber products.

Standard hardness of solid rubber in Shore A:

• 90 ShA
• 88 ShA
• 82 ShA
• 80 ShA
• 75 ShA
• 70 ShA
• 65 ShA
• 60 ShA
• 50 ShA
• 40 ShA

Sponge rubber hardness in Shore A:

• 30 ShA
• 25 ShA
• 20 ShA
• 18 ShA
• 15 ShA
• 10 ShA
• 5 ShA

Rubber products available at POWER Rubber

The POWER Rubber rubber products store offers the following assortment:

• Rubber O-rings
• Seals
• Oil seals
• Sealing rings
• Rubber granulate mats
• Rubber sheets and plates
• Gym mats
• Micro rubber
• Solid and sponge rubber cords
• Vibration isolators
• Rubber bumpers

For professional advice, please contact us by phone at +48 22 292 40 24 or +48 505 16 03 03, by email (Power@PowerRubber.com), or via our contact form.