They are of particular value in connection with applications such as:
• Edge protection profiles, sealing profiles with and without metal carrier
• Sponge rubber profiles with and without bonding (self-adhesive foam)
• Rubber glazing and filler profiles
• Dual-hardness rubber profiles
• Door sealing profiles
• Custom-made products, frames, rings, lengths, butyl, mastic, flock coating,
notching, gluing, slip coating, etc.
Extrusion is used to manufacture products in continuous lengths with a uniform cross-section. This section can be quite simple, i.e. circular, annular, rectangular profiles, or very complex (window profile, rubber car seal). Some common materials used in rubber extrusion include EPDM, SBR, neoprene (CR), silicone, nitrile (NBR), and natural rubber (NR).
We
are used to finding them on electrical/electronic cabinets, automotive doors, windows/construction, oil and gas control panels, and general industrial generic products. These installations are predominately concerned with the exclusion of air, dust, gas and/or water as either partial or complete seals to lids, doors or panels, and will often include standard profiles – possibly in a
custom solution.
For optimum effectiveness, the compression of a typical edge protection sealing profile should be a maximum of 50 percent as, otherwise, the compression and recovery can be adversely affected. It is recommended the profile should be compressed 30-40 percent. Why is the compression set such an important parameter? When a flange gasket is compressed to
a specified thickness (for example, in a door seal), it exerts pressure on the surface of the flange but, after a while, this pressure will reduce because the rubber deforms and takes a set. If the deformation value (DVR) is too high, the elastic performance and the sealing effect will decrease and the seal may cease to function properly.
Read the full article in DPA's October issue