Nonwoven abrasive articles generally include abrasive particles bonded to a nonwoven fiber web by a binder composition. In one common type of nonwoven abrasive article, the nonwoven fiber web includes a lofty open (i.e., not compact or tightly entangled) fiber web made by a process other than weaving or knitting. Examples of known techniques for forming nonwoven fiber webs include card and cross-lap, and air laid techniques using staple fiber. Typically, the fibers are held together mechanically (e.g., by needletacking) and/or by use of a prebond resin that is applied before the binder composition abrasive particles, although this is not always done. Nonwoven abrasive articles are widely used for many polishing, grinding, and machining purposes.
Nonwoven abrasives articles are used to abrade a wide variety of substrates or workpieces made from, for example, wood, plastic, fiberglass, or soft metal alloys, or having a layer of enamel or paint. Typically, there is some degree of space between these abrasive particles. During the abrading process, material abraded from the substrate or workpiece, also known as swarf, tends to fill the spaces between abrasive particles. The filling of spaces between abrasive particles and/or fibers with swarf and the subsequent build-up of swarf is known as loading. Loading presents a concern because the life of the abrasive article is reduced and the cut rate of the abrasive article decreases (thus, more force may be required to abrade). In addition, loading is an exponential problem; once swarf begins to fill in the spaces between abrasive particles, the initial swarf acts as a “seed” or “nucleus” for additional loading.
To address the problem of loading, antiloading compositions have been applied to non-woven abrasive articles. These compositions often contain antiloading agents such as, e.g., metal stearates, in a binder resin. There remains a need for improved antiloading compositions for nonwoven abrasive articles that includes a lofty open fiber web.
USPTO Backgrounds
USPTO Backgrounds