Wax Emulsion Used as Anti-blocking Agent

    Wax emulsions and wax dispersions are additives made of stable fine wax particles homogeneously distributed in water. They are liquid and can be easily incorporated into coating and ink formulations through simple mixing.

    The particle size of wax emulsions is usually <1μm, thus having minimal impact on coating gloss;
    The particle size of wax dispersions (water-based or solvent-based) is typically >1-2μm, and their extremely fine particle size ensures thorough and uniform integration with other components in the formulation, thereby maximizing the desired effects.

    Wax emulsions can be stabilized by non-ionic emulsifiers (steric mechanism) or ionic emulsifiers (most commonly anionic) (electrostatic mechanism). A combination of anionic and non-ionic emulsifiers provides optimal stability for the emulsion, as wax particles are protected by both stabilization mechanisms.

    In addition, each stabilization mechanism not only has its own advantages and limitations but also significantly affects the overall formulation, increasing formulation flexibility.

    Wax Emulsion as Anti-Blocking Agent

    Anti-blocking is a term used to define the non-sticky state between two surfaces or the adhesion between two surfaces under the influence of temperature, relative humidity, or pressure.

    A well-known example of blocking is when a freshly painted window frame is closed too early; sometimes, it can be very difficult to open the window again. Factors affecting blocking include:

    Wax emulsions are also widely used as anti-blocking agents for items that are coated, dried, and immediately stacked or rolled up for storage or transportation.