Factors to Consider When Preparing Wax Emulsion

    Wax emulsion technology is now mature and widely used in various water-based formulations. These ready-to-use wax emulsions can be easily incorporated into formulations through simple mixing.

    The wax properties that most affect formulation performance include:

    Solid wax melting point: When curing is required, it is important that the wax's melting point is lower than the curing temperature. Therefore, the wax can:

    Coating Thickness Layer: To maximize the effectiveness of the wax, it is important to achieve the highest dry wax density on the surface of the dried film. Therefore, the particle size of the wax emulsion should be as close as possible to the coating thickness. Sometimes, wax emulsions with smaller particle sizes can perform equally well as long as the concentration is properly adjusted.

    pH Value of Wax Emulsion: The pH value of the wax emulsion should be within approximately one unit of the system into which it is added. If necessary, the pH value of the emulsion can usually be adjusted using ammonia water or acetic acid.

    The type of surfactant also affects compatibility with other components and the stability of the overall formulation. Matching the emulsion charge with the coating charge can enhance stability.

    Order of Component Addition: In water-based formulations, the order of component addition can be a key factor in maintaining stability. Adding the wax emulsion last prevents agglomeration and maximizes overall stability. Further dilution of the emulsion with soft or demineralized water before incorporation can also reduce impact.

    Regulatory Aspects of Wax: If the emulsion is intended for food contact applications (in coatings or packaging), the wax and other incorporated additives (emulsifiers, defoamers, biocides, etc.) must comply with applicable regulations (FDA, BfR, national food safety certifications, etc.).

    Determination of Wax Content in Formulations.