Anti-slip and Abrasion Resistance of Wax Emulsion

Impact of Solid Wax on Slip and Flow Properties

    Slip properties (or lubricity) refer to the ability of two surfaces to slide against each other without causing mechanical damage. Good slip requires additives to concentrate on the surface during application, curing, and immediately after curing.

    Generally, the harder the wax, the better the slip properties. Solid wax crystals are the main contributors to slip characteristics. Softer waxes tend to liquefy more easily, resulting in a lower proportion of solid crystals. Harder waxes resist liquefaction and retain a relatively high proportion of solid crystals to provide lubricity.

    Anti-slip properties are achieved by increasing the friction coefficient of the cured coating to control surface energy, which can be realized by adding wax surface modifiers. Due to this property, waxes are widely used in applications such as inks, OPVs and primers, paper, film and foil coatings, and metal coatings. In particular, polypropylene waxes or wax emulsions:

• Control slip without adversely affecting scratch and mar resistance;
• Exhibit good migration properties to increase wax density on the coating surface.

    When formulating with polypropylene wax emulsions, it is critical to match the emulsion particle size to the coating to maximize the wax’s effect on the surface. Wax emulsions can also be used as anti-slip agents in floor polishes.

Impact of Wax on Abrasion Resistance

    Abrasion resistance results from a combination of fundamental properties such as elasticity, hardness, strength, toughness, and in some cases, thickness. Similar to slip additives, a trend has been identified between wax hardness and resistance to frictional damage: harder waxes offer better abrasion resistance than softer waxes.

    Owing to their anti-scuff, scratch-resistant, and rub-resistant properties, wax emulsions are widely used in applications including architectural coatings and floor polishes, paper, film and foil coatings, inks, OPVs and primers, and metal coatings.