Dense rubber is a good choice for industrial applications where abrasion and wear resistance are most needed. Applications that will experience strong forces and need maximum impact absorption are good uses for a dense rubber profile. In the case of a seal between two surfaces, a dense rubber with a mechanical fastening device will provide maximum sealing capabilities to ensure no moisture or dust enters the area.
Dense compounds are also good choices for profiles that need to maintain a rigid shape, when compression is not required, as when a profile needs to slide onto an aluminum extrusion channel.
Most sponge rubber profiles are softer than dense rubber because of the air inside the profile. These profiles will typically compress easier than dense rubber and will bounce back to their original shape without getting indented. Because of the lower compression force required they are used regularly in compartment and door seals where there is no mechanical fastening involved. The uses for sponge rubber profiles are too many to mention, but they can be commonly found in applications involving weather-stripping, insulation, and vibration dampening.
Sponge rubber has two main classifications of cellular structure: closed-cell and open-cell. We almost exclusively use a closed-cell structure sponge rubber at Uni-Grip because of its resistance to being permeated by liquids and gases. A closed-cell structure has individual pockets of air which are separated from each other inside the lattice structure. This structure makes it more difficult for air, fluids and gases to permeate into the air pockets. This reduces the time it takes for the profile to recover after being compressed and protects the profile from waterlog when exposed to rain.
An open-cell structure is just the opposite of a closed-cell structure. The cell structure in the rubber is not a group of separate walled off pockets, but rather a group of interconnected structures that allow air to flow throughout the structure freely. This allows for a quick recovery of the profile when compressed, but also allows for liquid and gas to enter the structure and saturate it quickly. Not a great characteristic for keeping these elements out of your house, truck, toolbox or anything else.
Rubber is a very versatile material with a lot of characteristics such as hardness, tensile strength, elongation, specific gravity and more. Each of these characteristics can be modified by the compounder and made to be a perfect fit for the application. Uni-Grip also makes dual-durometer profiles which have a dense rubber carrier and a sponge rubber bulb, combining the gripping power and strength of dense rubber along with the compression and sealing characteristics of sponge. Don’t worry if you aren’t sure exactly what you need, just give us a call and we can help you find the seal and compound that’s right for you.