Wax emulsion is a stable mixture of one or more waxes in water by high pressure homogenization. Since wax is solid at room temperature, a wax emulsion should definitely be called a wax dispersion. However, since the preparation takes place above the melting point of the wax, the actual process is called emulsification. In practice, wax dispersion is used for solvent-based systems.
Wax emulsions can be used in: inks and finishes, leather and textiles, paper, wood, metal, lacquer, glass fiber sizing, glass bottle protection, as well as are widely used in various technical applications. The most important properties that can be improved by the addition of wax emulsions provide matting and gloss, hydrophobicity, soft touch, wear and friction resistance, scratch resistance, release, corrosion protection. Emulsions based on natural waxes are used for coating fruit and confectionery and protecting the crop. Synthetic wax-based emulsions are often used in food packaging.
Carnauba wax emulsion is a very rich concentrate for dilution with water and is therefore extremely economical. The carnauba wax emulsion is self-gloss and does not require polishing. If necessary, further increase in brightness can be achieved by polishing. Carnauba wax is derived from the leaves of a Brazilian palm tree.
Generally Wax and water can be mixed at high temperature. The effects of homogenization: The water is heated until it reach the melting point of the wax. Molten Wax is slowly added to the water phase with good agitation. The agitation should be sufficient to disperse the molten Wax efficiently, but the vortex should be minimized to avoid entraining large amounts of air.
After a good premix is produced, the hot Wax/water mixture is homogenized. The rang of the pressure is around 200-350 bar depending on the desired particle size range.
The effects of homogenization: After homogenization, the emulsion is rapidly cooled to “set” the Wax particles. After homogenization, the wax emulsion is rapidly cooled. For good stability and mechanical properties, wax particles should be below 2 or 3 micrometers.
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