What are Coated Abrasives

November 11, 2020

What are Coated Abrasives?

What are Coated Abrasives

The surface-treatment tasks involve deburring, blending, grinding, polishing, finishing, dimensioning, patterning, or shaping a metal workpiece. There's a coated-abrasive product available to urge the work done. The products include belts, rolls, sheets, pads and flap discs, and wheels.

What is Coated Abrasive?

The coated-abrasive name derives from one layer of abrasive grains being coated or deposited onto a versatile or semi rigid backing material using an adhesive, like resin bond the grains to the backing material. This text examines the coating process, various sorts of grains, man-made minerals, and backing materials for coated-abrasive products for several metalworking applications.

A coated abrasive may be a product that consists of a skinny layer of abrasive grain attached to a substrate like paper, cloth, etc. Coated abrasives are available through forms like sheets, discs, rolls, specialties, or belts.

What are the Components of Coated Abrasives?

Following are the components of coated abrasives:

  • Abrasive Grains

Coated abrasives are developed using abrasive grains. The foremost common abrasive grains are alumina, zirconium, ceramic, carbide, and garnet. 

The grains are crushed and separated into sizes that are grit sizes, using calibrated screens. Grit size ranges from 12 (very coarse) to 1200 (very fine). Once the grains are separated into sizes, they're attached to a backing material using various bond techniques. 

Below are descriptions of the foremost common abrasive grains:

  • Ceramic

It is a high performance, man-made abrasive, which is a very uniform, high-density grain structure. Ceramic is extremely durable and self-sharpening for extended life and a more relaxed cut. Excels on tough to grind materials.

  • Aluminum Oxide

It is a challenging, blocky shaped, man-made grain used for top speed grinding and finishing metals, wood, and other high-lasting materials without excessive fracturing or shedding. The power to resist fracturing is that the primary consideration, alumina, will outperform all other coated abrasive grains.

  • Zirconium

Zirconium is an excellent, dense, man-made crystalline grain used for aggressive stock removal. Zirconium may be a very thick material with a singular self-sharpening characteristic, which provides its long life on massive stock removal operations.

  • Silicon Carbide

It is a rigid, very sharp, man-made abrasive fitted to non-ferrous materials and non-metallic materials like concrete, marble, and glass. A friable grain, carbide cuts faster under light pressure than the other grain utilized in coated abrasives.

  • Garnet

Garnet is formed of natural alumina, which may be a relatively strong but fragile bonding structure. Very inconsistent in comparison to synthetics. It's used primarily in woodworking as garnet dulls too quickly to be utilized in metalworking.

Types of Backing Materials

Below are the four significant sorts of backing materials:

  • Paper

Specialized technical papers are used as substrates for coated abrasives. They're identified by letters which represent weight and flexibility:

"A" and "B" weights are lightweight and highly flexible.

"C," "D," "E," "F" weights are medium to heavyweight for more strength and less flexibility.

  • Cloth

Cloth backings are more durable than paper backings. There are several types of cloth backings: cotton (i.e., Egyptian), polyester, and polyester-cotton blends. 

Cloth backings are also recognized by weight and flexibility: 

"F" weight (J-Flex) is light and highly flexible. This lighter weight is suitable for cleaning, finishing, and polishing. 

"J" weight (Jeans) is very flexible and suitable for cleaning, finishing, and polishing contour surfaces. 

"X" weight (Drills) is medium to heavyweight for more strength and sturdiness. It's low flexibility suitable for grinding, deburring and finishing. "H" (Heavy Duty) may be a heavier weight than "X" weight. It's low flexibility and is suitable for heavy-duty grinding and deburring applications.

  • Fiber

Fiber backing is a rigid vulcanized material made up of rag stock. This backing is typically used for abrasive fiber discs.

  • Combination Backing

Combination backing is both laminated paper and cloth and is extremely sturdy and shock-resistant. Combination backings typically are used for a good range of grits and mounting techniques.

  • Other Backing Materials

There is also a spread of other substrates like nylon fiber or screens, coated for special applications. Non-woven nylon impregnated with the abrasive grain is another substrate used for cleaning, polishing, or blending.

Essential Considerations for Coated Abrasive

  • Improper storage of coated abrasives will significantly affect performance. All kinds of backings are vulnerable to variations in temperature and humidity during storage.
  • Maintain the stockroom at constant levels of humidity (35-50%) and temperature (60-80° F)
  • Keep cartons faraway from damp or cold walls and floors where they'll absorb moisture.
  • Store coated abrasives far away from any heat source.
  • Keep products in original packages for straightforward handling and stacking.
  • Fiber discs far away from the first packaging should be stored during a suitable disc holder and kept struggling. 
  • Precondition the coated abrasive products during humidity and temperature controlled environment before use for max efficiency