Questions

1. Won’t Cork absorb water like a “sponge” if it gets wet?

2. Isn’t “Cork just Cork” and aren’t all Cork Underlayment products the same?

3. At what temperatures will CorkRubber operate?

4. Will Cork Underlayment compress and crumble under heavy loads and traffic?

5. Will Cork Underalyment “swell” with exposure to moisture and cause finish floor coverings to fail?

6. Will Cork support the growth of mold and mildew if used on in a moist environment?

7. Will Cork Underlayment material fall apart if it gets wet after it has been installed?

8. Will CorkRubber gaskets provide the same residual bolt torque over the life of the part?

9. When I replace my fiber gasket with a CorkRubber gasket, what is the thickness I should use?

Answers

1. Won’t Cork absorb water like a “sponge” if it gets wet?
Not true. Think of the most common use for cork, wine stoppers. Cork has been used as wine stoppers for hundreds of years primarily because it does not absorb water or liquids. Cork has also been used for years in buoys, lifejackets and other floatation devices, again because it does not absorb water and can remain buoyant for years. A cubic inch of solid cork immersed in water for 48 hours will gain less than 3% in weight due to water absorption. A cubic inch of solid wood or unglazed ceramic tile would gain more than 10 times that percentage in weight if immersed in water for 48 hours.

2. Isn’t “Cork just Cork” and aren’t all Cork Underlayment products the same?
Incorrect. Properties such as density, particle size and consistency of particle size are very important and vary widely from one manufacturer to another. Density affects the structural stability of the product and the sound attenuation quality. A product that lacks density will be too delicate to use as an underlayment and a product that is too dense will have poor sound attenuation characteristics. A product that has too large of particle size or a wide range of particle sizes in the mix will lack the structural integrity to be effectively used as an underlayment.

3. At what temperatures will CorkRubber operate?
The operating temperatures of CorkRubber material vary with the type of polymer used. However, in low temperature operations, the cork in the CorkRubber compound improves material elasticity properties. This is because the Tg of cork is zero at -60C. At the high end of the temperature scale, the cork provides improved insulation properties to allow operations above the temperature of the polymer in short durations.

4. Will Cork Underlayment compress and crumble under heavy loads and traffic?
No, just the opposite is true. Unlike open or even close- celled synthetic foam materials, cork consists of an interlocking structure of 14- sided polygons called tetracadecahedrons. These totally sealed gas filled cells have a very tough outer surface that is almost impossible to break. Because of this unique natural attribute, cork has a compression/recovery rating of close to 100%. Unlike foam and fiber based products, it will not collapse over time with traffic. The binders used to adhere the granules of AcoustiCork™ products together are designed to create a permanent structural bond between the particles.

5. Will Cork Underalyment “swell” with exposure to moisture and cause finish floor coverings to fail?
No. Because cork absorbs so little water it is very dimensionally stable. When exposed to 100% Relative Humidity conditions for 30 days the dimensional change in the grade of materials used to manufacture AcoustiCork products is less than 3%. In a 6mm” thick piece of material this would represent an increase in thickness of less than 1/120 of an inch.

6. Will Cork support the growth of mold and mildew if used on in a moist environment?
No. Going back to the traditional use of Cork in wine stoppers, Cork is used for sealing fine vintage wines precisely because it does not support the growth of molds and other biological agents that can cause spoiling of the wine.

7. Will Cork Underlayment material fall apart if it gets wet after it has been installed?
No. That may have been the case over 20 years ago when animal protein binders were used, but not anymore. Since the early 80’s non-water-soluble polyurethane binders have been used to adhere the granules together to make Amorim composition cork products. AcoustiCork™ products can be totally immersed in water for 30 days or more and show no signs of structural deterioration. The polyurethane binders are non-polluting producing no post installation off gassing and they do not leech into ground water supplies.

8. Will CorkRubber gaskets provide the same residual bolt torque over the life of the part?
The ideal flange system would have the same loading in all areas of the flange. When fiber materials are compressed, the majority of the load is retained under the head of the bolt relying on the density of the material to seal the distortion of the flange in between bolt spans. When corkrubber is compressed, the cork reacts with the rubber to provide more even transfer of the bolt load to the areas between bolt spans because of the lateral flow of the rubber. Because the area of sealing is improved and the distribution of load is more balanced, the torque retention is decreased. In reality, the corkrubber creates an improved sealing system.

9. When I replace my fiber gasket with a CorkRubber gasket, what is the thickness I should use?
Depending on the location of the cover, the same thickness should be used. However, if the cover is part of a system that has a critical alignment, then the compressed thickness of the fiber gasket should be matched with the compressed thickness of CorkRubber gasket.