The raw materials used have a great deal of influence on the material’s properties.
Material type
sponsrubber
A material is a naturally or artificially produced substance that is to be further processed into semi-finished or finished products. The right material can be chosen based on the properties needed for your application. Important properties include hardness, elasticity, durability and cost.
Color
black
Most of our product range comes in black, grey or white. We can also supply materials in other colours, such as red, yellow, green or blue. Please bear in mind that there is always some tolerance with respect to colour. The degree of tolerance varies between materials and is greater in some than in others.
Cell structure
closed cell
The cell structure indicates whether a material is open, semi-closed or closed. In materials with a closed cell structure, all cells are closed and the air cannot escape the cells. Materials with a closed cell structure can generally only be compressed by a certain percentage before the cells burst and the material disintegrates. By contrast, the air in materials with an open cell structure can enter and leave the cells. For this reason, open-celled materials can usually be completely compressed. Semi-closed materials fall between these two types. If the material is not compressed, air can circulate through it to a limited extent. But once the material is compressed by a certain percentage, the cells close and the material becomes closed in structure.
Hardness (Shore A)
15 shore A
The Shore A hardness scale is used to indicate the hardness of rubber and sponge rubber. Shore A hardness concerns measuring the depth of impressions made in a material under a certain force, using a Shore A meter. Measuring the Shore A hardness of harder materials such as rubber should be done correctly, but there will always be some tolerance with respect to the measurement result. This is because there is tolerance on the material itself, which can sometimes be a little harder or softer. This difference can occur between different production batches, as well as within the same production batch. Of course, we select our raw material suppliers on the basis of consistent quality and hardness, but there will always be some degree of tolerance with respect to hardness.
Density
600 kg/m³
A material’s compactness or density expresses the mass of that material present in a given volume. For most of our products, this is expressed in kg/m³. The manufacture of any given material always allows for tolerance on density. This cannot be avoided, unfortunately, but it is accurately tracked in quality controls. We measure the density or specific gravity of materials in accordance with international standards. This enables materials to be more effectively and accurately compared.
Density range and norm
500 to 700 kg/m³ (DIN EN ISO 845)
Possibilities Material
Self adhesive possibilities
without adhesive
The self-adhesive options depend on the properties, shape and intended application of the material. We can supply most materials unglued (without a self-adhesive side), with one self-adhesive side, and with two self-adhesive sides. However, some materials cannot have glue applied to them, and there are some profiles that we can only supply with one self-adhesive side.
Most sold thicknesses
2, 3, 4, 5 mm
While the most commonly sold thicknesses provide an initial indication of the standard options available, there are many more possibilities. If the thickness you are looking for is not listed, please contact us. We can often can easily customise the thickness, and there may also be an alternative material that comes in the desired thickness.
Minimum thickness
2 mm
The minimum thickness gives an indication of our technical capabilities, and is often a standard thickness. Should you need thinner material, however, please contact us. Sometimes we can provide this, and other times we can supply alternative materials in the desired thickness.
Maximum thickness
10 mm
The maximum thickness gives an indication of our technical capabilities. Should you need thicker material, however, please contact us. For some materials, we can glue several layers together to achieve the desired thickness, while for other materials we can use larger blocks. The possible solutions usually depend on the other desired dimensions and shape.
UV resistance
very good
Ozone resistance
very good
Application with oil
bad
Contact with copper and silver
bad
Depending on the substances used during the vulcanisation process, the foam rubber, sponge rubber or rubber either reacts (corrosively) or does not react (non-corrosively) with silver and copper. If contact with silver and copper is expected, for example in an application involving contact with jewellery, then a non-corrosive material should be used.
Sealing for which joint types
level/parallel
flat = smooth surface like metal/uneven = irregular surface like masonry/parallel = a joint that is very constant/gradient = a joint that varies a lot in thickness. Smooth and flat joints are not a problem, but irregular and gradient joints can be challenging. When it comes to masonry, for example, any unevenness should be properly accommodated but still provide a good seal. For gradient joints, the material should be very compressible, but still provide an effective seal in the areas where the tape is much less compressed.
Technical Properties Material
Temperature range
-35 °C to +120 °C
FMVSS302
compliant
The Federal Motor Vehicle Safety Standard (FMVSS) 302 is an international test that measures the flammability of a material. This standard specifies the burning behaviour exhibited by a material. If a material is compliant, this means that a certain minimum level of safety is guaranteed.
Linear shrinkage 22h, 70 °C
< 5%
Water absorption
< 3% (ASTM D1056-14)
Compression deflection 25%
50 kPa (35 - 65 kPa, ASTM D1056)
The amount of force needed to compress the material by 25%, expressed in kPa. For compression by 25%, we generally work with the following standard ranges: 0-15, 15-35, 20-50, 35-65, 65-90, 90-120 and 120-175. The ranges are fairly broad, but do give a good idea when comparing materials of different hardnesses.
Compression set: 50%, 24h, 23 °C
15% (< 25%, ASTM D 1056-07)
The compression set measures how well a material expands back to its original thickness. During the test, a material is compressed by a specific percentage for a specific amount of time at a specific temperature. The loss is expressed as a percentage. The lower the percentage, the better.
Tensile strength MPa
1 MPa (> 0,75 MPa, ISO 37)
How much force must be applied before a material breaks? Tensile strength is a measure for classifying a material’s mechanical properties. The tensile strength limit value indicates the minimum amount of force or stress a material can withstand before it breaks.
Elongation
300% (> 250%, DIN EN ISO 1798)
The elongation is a measure of the material’s elasticity, and relates to its tensile strength. It indicates the percentage by which the material is elongated when the specified force of tensile strength is used. The elongation is expressed as a percentage of the original length: 120% means that the material can be stretched by 20% of its original size before it breaks.
Maximum % of compression
0.5
This indicates the maximum percentage by which a material can be compressed without breaking the material. For example, if closed-cell foam is compressed by more than 50%, the cells burst. The maximum compression percentage for harder materials is much lower. Very soft materials with an open cell structure can often be almost completely compressed.
Applications, Standards
REACH
compliant
REACH is a European regulation that deals with which chemical substances should not be included in materials. The main idea behind it is the improved protection of human and environmental health from the risks of chemicals. This list of substances is regularly modified and expanded, and EKI monitors this on an ongoing basis.
RoHS
compliant
The RoHS (Restriction of Hazardous Substances) directive is concerned with limiting the use of hazardous substances in electrical and electronic equipment. This standard is therefore mainly used in the electrical industry and is regularly updated. EKI monitors this on an ongoing basis.
Recyclable
compliant
We are already recycling residual waste from our production process as much as possible. In most cases, this means grinding the rubber or foam into small pellets that are then reused as the basis for new products. If customers return residual waste, EKI includes it in this recycling process.
CFC and HCFC free
compliant
In short, the material is ozone-friendly. We get this question regularly at EKI, especially from sealant companies. Although the question is more applicable to some materials than to others, we have extended this notion throughout our entire range.
Shelf life
2 years
The amount of time a material may remain in stock after it has come in, before being used. This is based on an assumption of normal indoor conditions, and that the material is still in its original packaging. Our guideline is a temperature of 20°C and relative humidity of 40% to 50%.
HS code
40081900
HS (Harmonized System) code is an international standard for categorising goods, and is mainly used for export purposes.
General Description
Raw material
EPDM
The raw materials used have a great deal of influence on the material’s properties.
Material type
sponsrubber
A material is a naturally or artificially produced substance that is to be further processed into semi-finished or finished products. The right material can be chosen based on the properties needed for your application. Important properties include hardness, elasticity, durability and cost.
Color
black
Most of our product range comes in black, grey or white. We can also supply materials in other colours, such as red, yellow, green or blue. Please bear in mind that there is always some tolerance with respect to colour. The degree of tolerance varies between materials and is greater in some than in others.
Cell structure
closed cell
The cell structure indicates whether a material is open, semi-closed or closed. In materials with a closed cell structure, all cells are closed and the air cannot escape the cells. Materials with a closed cell structure can generally only be compressed by a certain percentage before the cells burst and the material disintegrates. By contrast, the air in materials with an open cell structure can enter and leave the cells. For this reason, open-celled materials can usually be completely compressed. Semi-closed materials fall between these two types. If the material is not compressed, air can circulate through it to a limited extent. But once the material is compressed by a certain percentage, the cells close and the material becomes closed in structure.
Hardness (Shore A)
15 shore A
The Shore A hardness scale is used to indicate the hardness of rubber and sponge rubber. Shore A hardness concerns measuring the depth of impressions made in a material under a certain force, using a Shore A meter. Measuring the Shore A hardness of harder materials such as rubber should be done correctly, but there will always be some tolerance with respect to the measurement result. This is because there is tolerance on the material itself, which can sometimes be a little harder or softer. This difference can occur between different production batches, as well as within the same production batch. Of course, we select our raw material suppliers on the basis of consistent quality and hardness, but there will always be some degree of tolerance with respect to hardness.
Density
600 kg/m³
A material’s compactness or density expresses the mass of that material present in a given volume. For most of our products, this is expressed in kg/m³. The manufacture of any given material always allows for tolerance on density. This cannot be avoided, unfortunately, but it is accurately tracked in quality controls. We measure the density or specific gravity of materials in accordance with international standards. This enables materials to be more effectively and accurately compared.
Density range and norm
500 to 700 kg/m³ (DIN EN ISO 845)
Possibilities Material
Self adhesive possibilities
without adhesive
The self-adhesive options depend on the properties, shape and intended application of the material. We can supply most materials unglued (without a self-adhesive side), with one self-adhesive side, and with two self-adhesive sides. However, some materials cannot have glue applied to them, and there are some profiles that we can only supply with one self-adhesive side.
Most sold thicknesses
2, 3, 4, 5 mm
While the most commonly sold thicknesses provide an initial indication of the standard options available, there are many more possibilities. If the thickness you are looking for is not listed, please contact us. We can often can easily customise the thickness, and there may also be an alternative material that comes in the desired thickness.
Minimum thickness
2 mm
The minimum thickness gives an indication of our technical capabilities, and is often a standard thickness. Should you need thinner material, however, please contact us. Sometimes we can provide this, and other times we can supply alternative materials in the desired thickness.
Maximum thickness
10 mm
The maximum thickness gives an indication of our technical capabilities. Should you need thicker material, however, please contact us. For some materials, we can glue several layers together to achieve the desired thickness, while for other materials we can use larger blocks. The possible solutions usually depend on the other desired dimensions and shape.
UV resistance
very good
Ozone resistance
very good
Application with oil
bad
Contact with copper and silver
bad
Depending on the substances used during the vulcanisation process, the foam rubber, sponge rubber or rubber either reacts (corrosively) or does not react (non-corrosively) with silver and copper. If contact with silver and copper is expected, for example in an application involving contact with jewellery, then a non-corrosive material should be used.
Sealing for which joint types
level/parallel
flat = smooth surface like metal/uneven = irregular surface like masonry/parallel = a joint that is very constant/gradient = a joint that varies a lot in thickness. Smooth and flat joints are not a problem, but irregular and gradient joints can be challenging. When it comes to masonry, for example, any unevenness should be properly accommodated but still provide a good seal. For gradient joints, the material should be very compressible, but still provide an effective seal in the areas where the tape is much less compressed.
Technical Properties Material
Temperature range
-35 °C to +120 °C
FMVSS302
compliant
The Federal Motor Vehicle Safety Standard (FMVSS) 302 is an international test that measures the flammability of a material. This standard specifies the burning behaviour exhibited by a material. If a material is compliant, this means that a certain minimum level of safety is guaranteed.
Linear shrinkage 22h, 70 °C
< 5%
Water absorption
< 3% (ASTM D1056-14)
Compression deflection 25%
50 kPa (35 - 65 kPa, ASTM D1056)
The amount of force needed to compress the material by 25%, expressed in kPa. For compression by 25%, we generally work with the following standard ranges: 0-15, 15-35, 20-50, 35-65, 65-90, 90-120 and 120-175. The ranges are fairly broad, but do give a good idea when comparing materials of different hardnesses.
Compression set: 50%, 24h, 23 °C
15% (< 25%, ASTM D 1056-07)
The compression set measures how well a material expands back to its original thickness. During the test, a material is compressed by a specific percentage for a specific amount of time at a specific temperature. The loss is expressed as a percentage. The lower the percentage, the better.
Tensile strength MPa
1 MPa (> 0,75 MPa, ISO 37)
How much force must be applied before a material breaks? Tensile strength is a measure for classifying a material’s mechanical properties. The tensile strength limit value indicates the minimum amount of force or stress a material can withstand before it breaks.
Elongation
300% (> 250%, DIN EN ISO 1798)
The elongation is a measure of the material’s elasticity, and relates to its tensile strength. It indicates the percentage by which the material is elongated when the specified force of tensile strength is used. The elongation is expressed as a percentage of the original length: 120% means that the material can be stretched by 20% of its original size before it breaks.
Maximum % of compression
0.5
This indicates the maximum percentage by which a material can be compressed without breaking the material. For example, if closed-cell foam is compressed by more than 50%, the cells burst. The maximum compression percentage for harder materials is much lower. Very soft materials with an open cell structure can often be almost completely compressed.
Applications, Standards
REACH
compliant
REACH is a European regulation that deals with which chemical substances should not be included in materials. The main idea behind it is the improved protection of human and environmental health from the risks of chemicals. This list of substances is regularly modified and expanded, and EKI monitors this on an ongoing basis.
RoHS
compliant
The RoHS (Restriction of Hazardous Substances) directive is concerned with limiting the use of hazardous substances in electrical and electronic equipment. This standard is therefore mainly used in the electrical industry and is regularly updated. EKI monitors this on an ongoing basis.
Recyclable
compliant
We are already recycling residual waste from our production process as much as possible. In most cases, this means grinding the rubber or foam into small pellets that are then reused as the basis for new products. If customers return residual waste, EKI includes it in this recycling process.
CFC and HCFC free
compliant
In short, the material is ozone-friendly. We get this question regularly at EKI, especially from sealant companies. Although the question is more applicable to some materials than to others, we have extended this notion throughout our entire range.
Shelf life
2 years
The amount of time a material may remain in stock after it has come in, before being used. This is based on an assumption of normal indoor conditions, and that the material is still in its original packaging. Our guideline is a temperature of 20°C and relative humidity of 40% to 50%.
HS code
40081900
HS (Harmonized System) code is an international standard for categorising goods, and is mainly used for export purposes.
Disclaimers
The published technical data is based on research data and serves as a guide for the various applications. Due to the great diversity of products and application possibilities, the buyer must test himself whether the intended material meets the requirements. All information is subject to typing errors, mistakes and market developments and no rights can be derived from this.
