Specific applications of white fused alumina in optical fiber polishing paper,polising pads and polishing belts

Specific applications of white fused alumina in optical fiber polishing paper,polising pads and polishing belts

I. Core Advantages of White Fused Alumina for Fiber Optic Grinding (AO aluminum oxide is also called white corundum, white fused aluminum oxide).

Fiber optic polishing targets ceramic ferrules, quartz fiber end faces, LC/SC/FC/MPO connectors, and glass capillaries, requiring low scratches, low subsurface damage, compliant end face 3D parameters, and no metal contamination. White fused alumina micropowder is the main abrasive used in the intermediate/fine polishing process.

1. Balance between hardness and toughness 

White fused alumina has a high-purity α-Al2O3 main crystal phase, a Mohs hardness of 9.0, and a microhardness of 2200~2400 kg/mm2. Its toughness is much higher than that of silicon carbide. During grinding, the particles are micro-fractured and self-sharpened, and will not break off in whole and scratch the optical fiber. It has stable cutting and uniform end face roughness, and is suitable for soft and hard composite grinding of quartz glass and zirconia ceramic ferrules.

2. Ultra-high purity, zero pollution

White fused alumina with Al2O3​≥99.4%, Fe2O3≤0.06%, extremely low heavy metal impurities; ground iron-free elements are embedded into the ferrule/optical fiber, which will not cause black spots on the end face and increase optical loss, and meet the clean production standards of optical communications.

3. Low thermal damage, not easily ablated end face

White fused alumina has good thermal stability and low heat generation during grinding, avoiding high-temperature crystallization of quartz optical fibers and thermal deformation of ceramic ferrules, thus ensuring the stability of 3D indicators such as radius of curvature and vertex offset.

4. Strong chemical inertness

White fused alumina is resistant to acids and alkalis, and is suitable for water-based polishing fluids and neutral polishing oils. It does not react chemically with glass or ceramics, and is easy to clean without residue after polishing.

5.Concentrated Particle Size Distribution

White fused alumina uses the most traditional water-washing overflow grading process, which can stably produce a full range of ultrafine powders from #240mesh to #30000mesh, without any large coarse particles, eliminating deep scratches; it can be used to make coated abrasive paper/belts, resin-bonded abrasive discs and other products.

II. Division of Labor and Application Scenarios of White Fused Alumina in Three Types of Optical Fiber grinding Paper, grinding Disc and grinding Belts.

Optical fiber polishing paper

Fiber optic polishing paper is a type of coated precision abrasive. White fused alumina is a special abrasive for intermediate and fine grinding processes. Coarse grinding often uses silicon carbide, and final polishing uses cerium oxide. White fused alumina undertakes the intermediate key scratch removal process.

1. Medium grinding removes deep scratches from coarse grinding: White fused alumina 600mesh 800mesh 1000mesh 1200mesh 1500mesh are used to quickly cut the ceramic ferrule allowance and smooth out the coarse marks left by SiC;

2. Fine grinding and pre-polishing: White fused alumina 2000mesh 2500mesh 3000mesh 4000mesh, which greatly reduces surface roughness and paves the way for final polishing with cerium oxide;

3. Ultra-fine pre-polishing: White fused alumina 6000mesh 8000mesh 10000mesh 30000mesh, used for high-precision connectors such as MPO multi-channel arrays and FA fiber arrays, to control the subsurface damage depth.

Fiber optic polishing pads

Fiber optic grinding wafer are divided into bonded hard polishing pads(for machine tool mounting discs) and adhesive-backed flexible polishing pads, with white fused alumina as the core filler.

1. Flexible Adhesive-Backed Polishing Pads: Multi-purpose white fused alumina (600mesh 800mesh 1000mesh 1200mesh 1500mesh 2000mesh 2500mesh 3000mesh 4000mesh 6000mesh) + flexible resin + non-woven fabric substrate, suitable for batch manual/semi-automatic fiber optic grinding.

2. Hard resin bonded polishing pads: High-filler white fused alumina micropowder+ phenolic/epoxy resin high-pressure molding.

Fiber optic polishing belts

Widely used in automated production line continuous grinding (MPO ferrule array, mass plastic/metal ferrule degumming and grinding): Polyester cloth base + white fuse alumina micropowder (#500-#3000mesh) coating, roll-type continuous consumable;

III. Key Technical Requirements for White Fused Alumina Micropowder Based on Fiber Optic polishing paper,polishing pads  and polishing Belts

1. Purity: Al2O3≥99.3%, Fe2O3≤0.03%, Na2O≤0.1% (Sodium impurities will reduce the resin bonding strength and cause abrasive detachment);

2. Particle size distribution: Concentrated particle size, with no free coarse particles.

3. Particle morphology: Multi-faceted and angular, with equal volume, avoiding needle-like or flaky particles (flaky particles are prone to collapsing and have poor cutting force)

4. Dispersibility: No agglomeration, no clumping during slurry preparation and sand application, ensuring uniform grinding film coating;

5. Impurity control: Free of free carbon and silicon impurities to prevent increased scattering loss at the optical end face.

IV. Industry Development Trends

With the development of the semiconductor industry, optical modules are driving increased demand for MPO and FA fiber arrays, leading to a continuous rise in demand for ultrafine white fused alumina powder (W1, W0.5). Simultaneously, the widespread adoption of automated grinding production lines is resulting in a year-on-year increase in the market demand for continuous white fused alumina grinding belts and large-size precision grinding films.

Zhengzhou Haixu Abrasives Co., Ltd., established in 1999, has been engaged in the production of white fused alumina powder. Utilizing the most traditional acid washing, water washing, and overflow grading process, the company achieves stable quality and highly concentrated particle size control.

The sizes of white fused alumina micropowder we produce are as follows: