SPONGE abrasives consist of three components: foam, usually made from EVA (ethylene vinyl acetate), PU (polyurethane) or recycled PU waste, a binder resin and abrasive grit made of aluminum oxide, white aluminum oxide, silicon carbide, semi-friable aluminum oxide and so on.
The Advantages of foam abrasives
When sanding with foam abrasives, the focus is not only on removing as much material as possible. It is vital to achieving an absolutely smooth and even result when preparing surfaces for subsequent painting or varnishing. If the goal is to achieve a perfect workpiece surface finish with low scratch depth, applying pressure in two dimensions when sanding (such as using conventional sandpaper) is not enough, for example when using paper-backed abrasives. Instead, pressure needs to be applied in three dimensions. Force can be applied in three dimensions by using the foam as the carrier material in connection with a flexible binder resin. This allows the grit to dissipate the contact pressure average. Advantage: the abrasive grit does not cut into the material as deeply and breaks off less. As such, less material is removed and no sanding through of the material occurs at the edges. Instead, we achieve a homogeneous surface.
Due to their conformability, foam abrasives are the ideal choice for areas that are difficult to access and have profiled surfaces. Hard-to-reach areas, such as door handle depressions, bumpers and radiator grilles, are ideal fields of application for the foam abrasives. Unlike conventional sandpaper, foam abrasives can be folded without creating permanent creases, which allows a consistent sanding pattern due to improved grain consistency without swirl marks.
A combination of soft carrier material and flexible grit bonding reduces clogging of the foam abrasives. Sanding dust is continuously removed from the spaces between the granules. Using more flexible binder resin and optimised distribution with improved abrasive grit, it has been possible to further improve the clogging characteristics. The sponge block sanding pad can therefore be used multiple times.
The foam allows the abrasive to shape itself to the product. With no folds or buckling, the material provides an even pattern free of scratching. A flexible abrasive surface lasts much longer than conventional surfaces, on which the abrasive grains crack apart and break off. With its soft backing material, the foam abrasive does not create pressure spots from fingers. It distributes the force of the sanding across the abrasive surface evenly.
Having a soft and flexible backing makes the foam abrasive continually release abrasive dust. Heat does not build up on the adhesive coating of the foam abrasive as you work. With less heat, there is less load up, and the product lifetime increases. Not only do foam abrasives work wet or dry, you can even wash and reuse them.
