Wax is anything that feels waxy. Whether they are natural (example: Carnauba wax), artificial (example: paraffin wax), or semi-synthetic (example: amide wax), this waxy feel is attributed to its lubricating properties.
A more modern definition of micronized wax goes like this: wax powder with granular particle size (10 mm on an average). It is single-chained paraffin formed by polymerizing ethylene or by reacting carbon monoxide with hydrogen in the Fischer-Tropsch process. The branched variants have higher molecular mass and offer increased hardness for a specific solubility.
Surface Properties of Micronized Wax
To pick the best kind of wax for a definite purpose, you need a sound understanding of its properties. Below are some salient features of micronized wax.
1. Coefficient of friction (CoF)
Coefficient of friction is the value determining the force required for two surfaces to slide past each other. A wax coated surface has considerably low CoF than one without wax.
2. Abrasion and Scratch Resistance
Sharp objects produce scratches while in abrasion the surface wears off due to frequent rubbing over a larger area with blunt or rough objects. A wax coated surface is scratch/rub resistant as the wax particles on the coating film acting as spacers forestall damages.
3. Anti-blocking Effects
The particles in the coating film stick together when pressed. This tendency is known as blocking, and it can considerably impair surfaces on separation.
Hydrophobic means water-repellent. Waxes offer excellent hydrophobicity by lowering the surface tension.
5. Matting Effects
The roughness of a surface causes light to scatter, thereby producing a matting effect. Several micronized wax variants (example polypropylene wax) have matting properties and help to attain desired surface texture.
Sprayed v/s Milled Micronized Wax
In micronization, waxes are manufactured by spray chilling and air jet milling. While sprayed wax has smooth and spherical particles, milled wax is made up of rough and irregular units. In the former, the melting step before micronization creates homogenous wax blends that offer better surface protection and low dust accumulation. In milled wax, differently structured particles stand side by side. Consequently, it allows for more viscosity and reinforced matting potential.
Micronized waxes have a wide range of applications, some of which are:
Before the advent of Shamrock’s micronization technique, for printing ink, coarse powders were milled. Today, micronized wax has remarkably boosted print speeds and durability in most thermal ink systems like transfer ribbons and toners.
Additives in Food
Food grade waxes are used as additives in chewing gums, chocolates, tablets, gelatin capsules, and others. The purpose is to form a film, act as a moisture barrier, add slip, make it glossy, or improve shelf life.
Micronization of wax helps it to enhance texture, increase stability, and regulate melting point in cosmetics and beauty care products.
Due to high linearity, improved crystalline behavior, low polydispersity, and optimum melting properties, this wax is best suited for mold release in PU applications and as EPS (expanded polystyrene) nucleating agents.
Additionally, this wax is also used in ceramics, coatings, and hot melt adhesives. To decide which variant will be best suited for your applications, you can take advice from experts in the chemical industry.