Zibo Sankyo Rikagaku Co., Ltd.
Zibo Sankyo Rikagaku Co., Ltd.


Q What are the three basic raw materials used in the manufacture of coated abrasives?

Grain – synthetic or natural abrasive particles.

Bond – adhesive that permanently bonds the backing to the abrasive.

Backing – the backing which the abrasive is bonded to.

Q What are the different types of abrasive grain?

The grains are crushed and separated into 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:

Aluminum Oxide

Aluminum oxide is the most common sandpaper or coated abrasive on the market. The grain consists of the durable furnace-produced mineral that does not break down easy, instead the mineral is designed to gradually wear until it becomes too dull to cut. These belts will provide a fast cut and long life for grinding and polishing.

Silicon Carbide

Silicon Carbide is a Sharper and Harder mineral than the traditional aluminum oxide. The grain consists of extremely sharp pointed grains that work great at cutting glass and plastics along with much more. Due to the design of the material, silicon carbide waterproof paper can be both used in wet or dry application.

Zirconia Oxide

Zirconia Oxide has an extremely tough grain the does well under heat and high pressure making it ideal for steel fabrication and in grinding applications.


Ceramic is extremely sharp, hard and wear slowly. Making this material ideal for removing a bunch of material fast. The grains are designed so it breaks down in a controlled manner allowing for a very consistent clean cut. Ceramic sanding disc in general performs best when moderate pressure is applied.

Q What are the different types of backings used in coated abrasives?

Paper backing

Coated abrasives are applied to specialized technical papers that serve as substrates. The letters used to identify them stand for weight and flexibility: "A" and "B" weights are light and extremely flexible.

Medium to heavyweights "C," "D," "E," and "F" are designed for more strength and less flexibility.

Cloth backing

Paper backings are not as strong as cloth backings. Fabric backings come in a variety of materials, including cotton (such as Egyptian cotton), polyester, and polyester-cotton mixes.

Other characteristics of cloth backings include weight and flexibility:

The "F" weight is quite malleable. For polishing, finishing, and cleaning, use this lower weight.

When it comes to flexibility and suitability for polishing, finishing, and cleaning contour surfaces, "J" weight excels.

Medium to heavyweight is "X" weight for added strength and durability. Low elasticity makes it ideal for finishing, deburring, and grinding.

In comparison to "X" weight, "Y" weight is heavier. It is excellent for heavy-duty grinding and deburring tasks and has minimal flexibility.


Most people agree that the film used for coated abrasives offers the best balance of toughness and flexibility for sanding discs. It offers a very smooth surface for the grains, is tear-resistant, and can be bent to fit contours. These characteristics make it suitable for both leveling/shaping and finishing tasks including orbital and manual sanding. On orbital sanders, film products (and paper as well) can be coupled with interface pads to help with contour sanding, eliminate swirls, and access difficult-to-reach areas.


White wood can be polished with coated abrasives on foam sponges, however they are often used for finishing tasks like sanding in between coats of finish. Typically, two types of foam are used: softer, more flexible foam and harder, less resilient foam. Uneeda offers two different types of sponges: ones with hook and loop backing for orbital sander use and those without, designed just for hand sanding.

Fibre Backings

Fibre is a strong, long-lasting material with excellent mechanical properties. The production of resin fiber discs uses it.

Q What is the difference between open and closed coated sandpaper?

Open coated refers to a coating in which 50% to 75% of the backing is covered by abrasive grain. There are voids between particles of grain which helps reduce the effect of clogging causes by sawdust or metal particles. Suitable for woods or plastic.

Closed coated refers to coating in which the entire surface of the backing is covered with abrasive grain, with no void between particles. This is by far the most general coating in use and permits the greatest degree of stock removal and the longest product life. Suitable for metal and woods.

Q What is sanding sequence?

When you sand in sequence, you start with the coarsest grit of abrasive paper that is suitable for the sort of material you are dealing with and work your way up to the finest grit. Sanding should be done in the following order: 80, 100, 120, 150, 180, 220, and 320...

Q How much longer will zirconia oxide or ceramic last compared to aluminum oxide?

Both ceramic and zirconia oxide are regarded as high performance grains. Both are going to endure a lot longer than aluminum oxide (3-5 times longer is quite common, or even more). Ceramic materials endure longer than zirconia oxide because of their micro grain structure, which enables smaller bits to break away during the grinding process.

On the other hand, as aluminum oxide fades, the grains become duller and the rate of stock removal decreases significantly. More pressure is needed to keep removing material as they get dull, which results in increased heat and operator fatigue.

Q What is the best way to store my abrasives?

The performance of coat abrasives is significantly influenced by temperature and humidity. The coated abrasive will have a shorter useful life if it is improperly stored. Because to their sensitivity to environmental fluctuations, backing and adhesives will absorb or release moisture depending on the relative humidity of their surroundings. The adhesive bond may be permanently harmed by changing weather conditions.

Certain types of adhesive bonds may become softer due to excessive humidity, which could result in the product filling up quickly and clogging or losing its grain while being used. Brittleness, diminished flexibility, and shape distortion are all potential effects of excessive dryness. Temperature and humidity should be kept at constant levels. Temperatures in stockrooms should range between 15 and 25 degrees Celsius, with a relative humidity between 35% and 50%. The walls and floors that are damp or cold, where cartons may absorb moisture, should be avoided. After being taken out of their packaging, belts should be rolled up and placed on an uncluttered shelf on their edges.

Q What is your delivery time?

Our delivery time is 60 days after getting the prepayment.

Q Do you accept OEM for customer's brand and what's the MOQ?

Sure, we'll need the brand registration certificate and bellowing is our MOQ policy.

Jumbo roll: 500m per grit and total grit quantity 3000m for the same product and charge USD300 printing cost. When it reaches 10000m, we will return the USD300.

Sheet: 10000pcs per grit and total grit quantity 100000pcs for the same product and charge USD300 printing cost. When it reaches 200000 sheets, we will return the USD300.

Q How do you guarantee the quality of your products?

We specialize in manufacturing coated abrasives for 20+ years and we are one of the top quality coated abrasive suppliers in China. The newest equipment and technology, well selected raw material and refining production process guarantee our high quality.

Q How is your after-sales services?

We provide both high quality products and professional services. If you encounter any quality problems with our products, please no hesitate to contact with us. we will analyze the kept sample and resolve for you as soon as possible. Once the proof is checked and confirmed, we will give you reasonable compensation for your lost.