Applications and Production of Varieties Aluminum Hydroxide 1

Today I would like to talk about the applications?of different grades?of aluminum hydroxide.?Besides being used as flame retardant, there are also many usages of aluminum hydroxide, such as a filler for carpet backing latex foam and adhesives, filler for artificial marble and artificial agate, paper making..., if you are interested, please keep reading.

1.The Classification of Varieties?Aluminum Hydroxide

According to the crystal structure, particle sizes, whiteness, this article divided varieties Aluminum Hydroxide into the below categories.

2.?The application of Varieties Aluminum Hydroxide

2.1?Flame retardant

Aluminum hydroxide is an ideal flame retardant filler for plastics and organic polymers. Because aluminum hydroxide is a white powder, its physical and chemical properties are stable, it does not absorb moisture, and its particle size can be processed and produced as needed. It has filling, flame retardant, and smoke suppression functions.

When a plastic or polymer burns in contact with an external heat source, it can be divided into the following stages: (1) heating (2) decomposition, (3) fire (4) combustion (5) spreading.

The?mechanism?of all flame retardants is to achieve the purpose of flame retardant by inhibiting one or more of the above-mentioned combustion stages. Aluminum hydroxide mainly works in the two stages of heating and decomposition. When the heating temperature exceeds 200 °C, the aluminum hydroxide begins to endothermic decomposition and releases three crystal waters. The reaction is a strong endothermic reaction, and the endotherm per gram of AI(OH) reaches 878J during decomposition, and the decomposition rate reaches the highest between 300 °C~380 °C, and this temperature is the decomposition temperature for most polymers. It is precisely based on a large amount of heat absorption when aluminum hydroxide decomposes, when the polymer containing aluminum hydroxide is heated, aluminum hydroxide absorbs heat due to decomposition, thereby inhibiting the rise of the polymer temperature and reducing its decomposition rate; Aluminum hydroxide emits water vapor when it is thermally decomposed, and does not produce toxic, flammable or corrosive gases, and at the same time dilutes various flammable gases produced by polymer decomposition, making it more difficult to spread.

The flame retardant performance of synthetic materials has a great relationship with the particle size of?aluminum hydroxide. As the particle size becomes finer, the oxygen limit?index?increases. Second, the refinement of fillers also contributes to the improvement of the smoothness and mechanical properties of synthetic materials. The content of alkali and iron oxide can improve the insulation performance of the material, which is particularly important in cable sheathing and low-voltage electrical switch products.

The polymer series of synthetic materials using aluminum hydroxide as filler include polyester, epoxy, phenolic, polypropylene, polyethylene, polyvinyl chloride, butyral rubber, neoprene rubber, silicone rubber, etc.

2.2?Used as a filler for carpet backing latex foam and adhesives

The application of aluminum hydroxide in the carpet industry is mainly to use the flame retardant filling properties of aluminum hydroxide. All latex in the carpet industry comes in two varieties, a binder and a foam.

A carboxylated latex coating is a binder used to bond and hold the carpet fibers bound to the mesh backing; latex foam is applied to the carpet surface to the desired thickness. The curing is done in an oven of 120~150?° C.

Usually, the proportion of the binder is 100phr?of latex to 75~250 phr aluminum hydroxide, while the ingredients in the foam are 100 phr latex with?20~150 phr aluminum hydroxide. In general, the aluminum hydroxide used in carpets is fine-grained aluminum hydroxide?D50≤20μm.

2.3?Used as a filler for artificial marble and artificial agate

We can use aluminum hydroxide and unsaturated polyester resin or methacrylic resin to produce artificial agate or artificial marble. Aluminum hydroxide and polyester resin have a similar refractive index, which can fabricate the artificial product with translucency, with different colors and decorative patterns. Compared with a natural product, the artificial product has many advantages, low cost, lightweight, not easy to crack, could be made to product with different colors, specifications. Therefore, artificial marble is widely used in high-end sanitary ware, kitchen decoration, conference tabletop, board, decorative board, etc.

In general, aluminum hydroxide used for artificial has high whiteness (＞95%), good crystal shape, and medium particle size(d50=50μm, 70μm).

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Feel free to contact Elena( [email protected]) for any inquiries, thank you.?