Find the right sheet rubber

Let’s face it sheet rubber properties are confusing. There are many rubber variations and polymer types to choose from. If not an experienced user, how do you select between Neoprene, SBR, EPDM or Nitrile sheet rubber?

This reinforces the importance of being well informed on the sheet rubber properties you are evaluating. A critical factor to consider is the operating environment your material will be subject to. Will the rubber be exposed to ozone or UV rays? Does it operate in continuous high-temperature conditions or semi-submerged in fluids? All end-use environments present different challenges. Fortunately, there is almost always a sheet rubber material designed to best perform for the conditions.

Outlined below are the most commonly evaluated rubber characteristics and their importance to application performance:

Durometer/Hardness

What it Measures: A material’s resistance to permanent indentation.

Common Measurement Scale: Shore A Durometer Scale

Test Method: ASTM D2240

Why is this Important: Durometer lets us know how easily the sheet rubber material is compressed under applied force. Therefore rubber with a low durometer rating will feel softer to the touch versus higher durometer materials.

Tensile Strength

What it Measures: The maximum amount of tension or stress a material can take before failure. Normalized by the cross sectional area.

Common Measurement Scale: Pounds per Square Inch (PSI) or Megapascal (MPa)

Test Method: ASTM D412

Why is this Important: Often is an important indicator regarding quality. The tensile strength of a rubber compound provides a measurement of the strength. 

Ultimate Elongation

What it Measures: The maximum amount of strain a material can take before failure (length at break divided by original length).

Common Measurement Scale: Percentage of Original Length.

Test Method: ASTM D412

Why is this Important: You may require a material which can be repeatedly stretched, bent or reshaped then return to original form. As a general rule rubber can extend by a large amount before failure.

Heat Resistance

What it Measures: The influence of elevated temperature on the physical properties of sheet rubber.

Common Measurement Scale: Percentage Change and Actual Change.

Test Method: ASTM D573

Why is this Important: Heat aging is a convenient way to preview how a material will perform in the application or after years of service.

Compression Set

What it Measures: The residual deformation of the rubber after it has been exposed to compression stresses at elevated temperatures for a set period of time.

Common Measurement Scale: Percentage Remaining of the Original Deformation.

Test Method: ASTM D395

Why is this Important: In applications where gaskets may need to be reused, or when dynamic forces or temperatures are present. The ability of the rubber to return to its original shape is especially important.

Tear Strength

What it Measures: How well a material can withstand the effects of tearing.

Common Measurement Scale: Pounds per Linear Inch (PLI) or kilonewtons per meter (kN/m)

Test Method: ASTM D624

Why is this Important: How well your chosen polymer will resist the growth of any cuts/nicks under tension is critical for highly abrasive environments.

Low Working Temperature

What it Measures: The lowest rated temperature environment the material should be used in.

Common Measurement Scale: Celsius (°C) or Fahrenheit (°F)

Why is this Important: Important for applications where prolonged exposure to low temperature conditions exists.

High Working Temperature

What it Measures: The highest rated temperature environment the material should be used in.

Common Measurement Scale: Celsius (°C) or Fahrenheit (°F)

Why is this Important: Important for applications where prolonged exposure to elevated temperatures may result in premature material degradation.