Page 32 - MetalForming April 2017

Finishing
via Non-Woven
Abrasives
Durable and conformable to workpieces, these products serve well across a variety of applications.
Apart isn’t finished until it’s fin- ished. Post-process deburring, cleaning and other finishing tasks deliver a final part with ideal sur- face quality. Abrasive products, such as bonded and coated abrasives, often get the call to remove part stock during production. But for final surface fin- ishing, non-woven abrasives are ideal.
Non-woven abrasives, using abra- sive-grain-embedded nylon fibers bonded together, offer durability and the ability to conform to a workpiece. This helps make the finishing process easier and less time-consuming. With these products, the nylon web features uniformly dispersed abrasive grain, so as wearing occurs, the grain is con- stantly replenished. Another plus: Non- woven abrasives are waterproof and can be washed. They will not rust, and with open-mesh construction, they will bounce back to shape easily and repeatedly, bringing long life.
These types of abrasives have ful- filled an important role in grinding applications, bringing capabilities unmatched by other grinding products, chiefly due to the relatively gentle nature of the nylon fibers and their
abrasive grains. Non-woven abrasives work on a range of metals, including aluminum, brass, copper, nickel, chrome plate, stainless steel and tita- nium, and nonmetals.
Types of Non-Woven Products
These products can come in many forms. Non-woven grinding wheels can be classified as follows:
• Flap wheels consist of sheets of non-woven material mounted around a center hub, ideal when conformabil- ity to a surface or a long-line brushed finish is required.
• Convolute wheels are made by wrapping non-woven material around a center core and bonding together the layers. These wheels can easily be shaped to match preformed parts.
• Unified wheels are formed by com- pressing multiple layers of non-woven web material and bonding them together to form a wheel. They find use for general-purpose cleaning and deburring.
Non-woven abrasives exist in other forms besides wheels. Fabricators use arbor-hole non-woven discs with high- speed grinders, with extra-coarse grit
often used to remove surface rust and residue, corrosion, light weld splatter and other surface contaminants. Spac- ers allow multiple discs to form a wide grinding wheel to provide sharp edge radiusing or deburring of decorative- finished parts. Portable grinders employ right-angle non-woven discs for various applications including cleaning, deburring, blending and fin- ishing, as well as for removal of oxida- tion and coatings.
Non-woven hand pads often are specified in wet applications as a replacement for steel wool due to rust issues. Also, non-wovens come in rolls of various widths, then cut for hand sanding or other sanding applications. Non-woven belts, alternatives to coated abrasive belts, can be used for cleaning, buffing and polishing. The belts con- form readily to workpieces, thus min- imizing gouging and producing a more consistent finish.
Meaning Behind the Specs.
Grit refers to the size of abrasive grains in the nylon web. Non-woven abrasives feature various grit sizes, from coarse—50 to 80 grit, often used for gen-
30 MetalForming/April 2017
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