The core reason why ultrafine white alumina oxide powder(electrofused α-Al₂O₃) is added to melamine paper:
Ultrafine white alumina oxide powder is commonly known as wear-resistant alumina sand in the industry. It is mainly added to the surface layer of wear-resistant impregnated paper and high wear-resistant decorative adhesive layer. The core purpose is to greatly improve the surface wear resistance and scratch resistance, while taking into account transparency, hot pressing stability, and chemical resistance. The following points are explained in detail:
1. Core function: Extremely improve wear-resistance and anti-scratch speed
Extremely hard, bears wear during friction White corundum has a Mohs hardness of 9, second only to diamond and silicon carbide, and much higher than melamine resin (Mohs 2 to 3), dust, sand and gravel on shoe soles, metal keys, furniture legs and other daily friction objects.
When the floor and door panels rub for a long time, the external force will only wear away the hard white corundum particles, and will not quickly wear through the resin to expose the wood grain paper underneath, which directly determines the wear resistance level of the floor (≥6000 rpm for home use, 12000 rpm or more for commercial use).
Self-sharpening and anti-scratch
The particles have fine edges and corners, and new sharp edges will continue to be exposed after slight wear, resisting permanent scratches caused by keys, tables, chairs, and sand, and solving the pain points of pure melamine resin being soft and prone to scratches.
2. Transparency does not cover the texture and does not damage the decorative effect.
Ordinary calcined alumina and calcium carbonate fillers will turn white and foggy, covering the wood/stone grain;
High-purity white corundum (Al₂O₃≥99.5%) has extremely low impurities and rounded particles. It is dispersed in transparent melamine resin and has good light transmittance. It is almost invisible after hot pressing and curing. The wood grain is clear and transparent, not whitening or graying, and does not affect the appearance of the finish.
3. Suitable for melamine hot pressing process, stable at high temperatures
High temperature resistance, no decomposition
The melting point of white corundum exceeds 2000℃, and the melamine hot pressing temperature is completely unchanged at 130~180℃, and will not yellow, soften or shrink;
Low oil absorption, easy to disperse
After water washing and surface activation treatment, the glue absorption amount is low, and it will not absorb a large amount of melamine glue, causing the paper to become brittle and the impregnation cost to rise; with a small amount of coupling agent, it can be evenly dispersed in the resin without agglomeration and white spots;
Non-stick steel plate, reduce indentation
The shaped and rounded particles will not scratch the mirror steel plate of the hot press during hot pressing, making demoulding smoother and the plate surface smoother.
4. Resistant to acid, alkali and corrosion, extending the life of the plate
White corundum is extremely chemically inert and resistant to corrosion by vinegar, detergents, disinfectants, sweat, and oil;
Ordinary calcium carbonate and talcum powder fillers will dissolve and turn white when exposed to weak acids. White corundum will not be eroded by daily cleaning chemicals and will not turn black or lose its luster after long-term use.
5. Reinforce surface hardness, impact resistance, and sand prevention
Evenly distributed rigid particles form a skeleton inside the resin, improving the overall surface hardness and making it less likely to peel off or chip away from slight bumps;
The densely packed structure reduces resin gaps and is waterproof and anti-penetration, making it difficult for stains to penetrate into the board.
Additional distinction: When to use white corundum and when not to use it?
White corundum must be added: laminate floor wear-resistant paper, office desks, commercial cabinets, elevator decorative panels, laboratory countertops and other high wear-resistant impregnated papers;
No white corundum is added: ordinary decorative wood grain paper, low wear-resistant backing board, only calcium carbonate/talcum powder is used for ordinary filling to reduce costs.
Summary of simple principles
Pure melamine resin has a soft texture and will become scratchy when polished. After adding white corundum particles with high hardness, high transparency and chemical stability, it is equivalent to burying countless micro-wear-resistant particles on the surface of the board. All friction losses are borne by corundum. At the same time, it does not block the pattern and is resistant to high temperatures and cleaning agents. It is the core filler for melamine facing to achieve high wear resistance.
