Home / News & Blog / Abrasive Blog / Coated Abrasives Substrates: Steel Paper, Mesh Cloth, Polyester Film, and Sponge
Coated abrasives are essential tools in various industries, enabling efficient material removal, surface finishing, and precision polishing. The foundation of any coated abrasive lies in its substrate, the base material that supports the abrasive grains and determines the tool’s performance and durability. From heavy-duty steel paper and clog-resistant mesh cloth to precision-focused polyester film and flexible sponge, each substrate type offers unique benefits tailored to specific applications. We delve into the properties, advantages, and industrial uses of different coated abrasive substrates, guiding manufacturers and users in selecting the ideal abrasive tool to optimize efficiency, productivity, and quality across diverse operations.
1. Steel Paper: also known as vulcanized fiber: It is a mixture of hardened paper and cotton cloth. It is usually used to make sanding discs, and the thickness is usually 0.6mm, 0.8mm, and 1.0 mm.
Thicker fiber backing is used to make straight sanding discs, which are called “steel paper sanding discs” in the market. They are usually disc-shaped, with abrasives adhered to their surface. Sometimes they have perforated designs to facilitate chip removal ventilation and heat dissipation. They can be directly installed on grinders or angle grinders for use. They can quickly grind materials and are suitable for large-area grinding and fast grinding. Wire paper sanding discs are widely used in metal processing, such as deburring, weld grinding, and surface treatment of steel, stainless steel, aluminum alloy, etc. They are also suitable for rough grinding and flat grinding of wood or for grinding treatment of stone and concrete surfaces.
In addition to flat grinding, some steel paper sandpaper discs are designed in the shape of blades and can be used for grinding curved surfaces, edges, and corners.
The thinner backing is used to make sand discs with better elasticity, which are usually called “steel paper grinding discs” in the market. They have high tensile strength, low elongation, smooth surface, good heat resistance, and can withstand particularly high mechanical loads. They are widely used in metal processing, such as removing oxide layers, welding seam grinding, surface cleaning, etc. They are also suitable for grinding materials such as stone and wood.
Both have similar particle size ranges, typically P24 – P120, to suit different processing needs.
Commonly used coarse grits: P24 and P36 are used for rapid material removal and surface cleaning, and larger grits are suitable for rougher surfaces.
Finer Grits: P80-P120, for surface leveling and smoothing.
2. Mesh Cloth
Made up of many mesh openings, the mesh specifications are usually 18 × 18 and 21 × 21. It is woven from polyester fibers and bonded with abrasive grains. Unlike traditional paper-based or cloth-based coated abrasives, the open structure of the mesh fabric allows debris and dust generated during grinding to pass through the mesh openings. This prevents clogging, thereby improving efficiency and extending the lifespan, making it an ideal tool for surface treatment of metals, wood, plastics, and more.
Grid cloth abrasives come in a wide range of grits, from coarse to fine, common grits include:
Coarse Grit: P40-P80, for removing larger areas of material or for heavy sanding.
Medium Grit: P100-P150, used for medium sanding needs, such as surface smoothing.
Fine Grit: P180-P320, suitable for fine sanding, can provide a smoother effect on the surface.
Ultra-Fine Grit: P400-P800 and above, used for ultra-fine polishing and surface treatment.
3. Polyester Film
This backing is made of smooth, high-strength, tear-resistant polyester film (PET), and after abrasives are coated on its surface, it is made into polyester film abrasives. This backing can provide consistent processing accuracy and low roughness value, high tensile strength, low elongation, dimensional stability, strong toughness, high impact strength, good heat resistance, low wear resistance and moisture absorption, high flatness, and can achieve precise grinding and polishing. Compared with traditional paper-based or cloth-based abrasives, polyester film abrasives have excellent performance in precision and durability due to the characteristics of the base material. They are mainly used in the following industries:
Used for precision grinding and polishing of metal parts, especially high-hardness metals such as stainless steel, titanium alloy, etc. Suitable for removing tiny burrs and oxide layers on various metal surfaces, as well as polishing welds.
Due to its high precision and smooth properties, polyester film abrasives are widely used for grinding and polishing optical glass, mobile phone screens and other electronic components, and can achieve a very fine surface finish.
It is suitable for sanding wood products and fine polishing of paint and coatings. It can effectively remove surface defects without damaging the paint surface.
In the automotive and aviation industries, it is used for polishing the surface of the car body and precision grinding of parts to achieve a high finish.
Polyester film abrasives have a wide range of grits, from coarse grinding to fine polishing, and various grit grades are suitable for different processing needs:
CoarseGrit: P80-P120, for rapid machining of rough grinding and material removal.
Medium Grit: P180-P32, suitable for medium-precision grinding and surface smoothing.
Fine Grit: P180-P320, for fine grinding and surface treatment with high requirements for smoothness.
Ultra-fine Grit: P1000-P2000, even finer for ultra-fine polishing to ensure a highly smooth surface.
4. Sponge
Sponge sand can be made by directly planting abrasives on a sponge, or planting sand on paper and then sticking it on a sponge. Thin sponge sand is called “sponge sandpaper”, and thicker blocks are called “sponge sand blocks”. “Beauty sandpaper” and “sponge nail files” belong to this category and are also classified as coated abrasives.
Sponge sandpaper uses a soft sponge as the base material, with abrasives adhered to the surface. It is typically sheet-shaped and used for manual or machine sanding. It combines the characteristics of sandpaper and sponge, offering flexibility and bendability, making it suitable for sanding curved surfaces, edges, and irregular surfaces. It also has a certain level of absorbency, effectively reducing clogging during sanding. It can be used for both dry and wet sanding and is suitable for surface treatment of various materials such as wood, metal, plastic, and paint. Common grits range from P60 to P800 and finer.
Sponge sanding blocks are abrasive tools in the form of cubes or blocks, with a soft sponge interior and an abrasive-coated outer layer. Compared to sponge sandpaper, sponge sanding blocks are thicker, offer greater support, and are easier to hold, making them especially suitable for tasks that require higher pressure during sanding. Additionally, sponge sanding blocks typically have a cubic structure, allowing for multi-surface use, and making them ideal for flat, concave, convex, and other complex surface treatments. Finally, their thicker structure makes sponge sanding blocks more durable than sponge sandpaper, making them better suited for long-term, high-intensity sanding tasks. Common grits range from P60-P400 and finer.
As an abrasive manufacturer, we need to pay special attention to the substrate of the coated abrasive manufacturer. The substrate limits the type and particle size of the abrasives used. The substrate must have sufficient strength and wear resistance to support the abrasive particles without falling off during grinding. For example, light paper, polyester film, non-woven fabrics, and sponge substrates rarely use coarse particles; heavy-duty sanding belts and heavy paper-based sanding belts mostly use high-toughness, coarse-grained abrasives for heavy-duty grinding. The substrate’s durability and toughness directly affect the abrasive’s service life, not just the abrasive.
Non-woven abrasive tools have transformed surface finishing processes, providing industries with efficient, reliable, and adaptable solutions. Their superior elasticity, self-sharpening properties, and wide range of particle sizes make them indispensable for tasks ranging from heavy-duty rust removal to precision polishing. Whether you’re involved in metal processing, automotive manufacturing, or aerospace engineering, leveraging the right non-woven abrasive tool can significantly enhance your productivity and product quality.
In conclusion, the choice of substrate in coated abrasives plays a pivotal role in determining their performance, durability, and versatility across various industries. Whether it’s steel paper for heavy-duty metal grinding, mesh cloth for efficient dust-free sanding, polyester film for precision applications, or sponge for flexible surface finishing, each material offers distinct advantages tailored to specific tasks. By understanding the unique characteristics and applications of these substrates, manufacturers, and end-users can optimize their abrasive tools for enhanced efficiency, longer service life, and superior results. Ultimately, selecting the right substrate not only improves productivity but also ensures a higher quality finish, meeting the diverse demands of industries such as metalworking, woodworking, automotive, aerospace, and electronics.
