ALL YOU NEED TO KNOW ABOUT PEARLESCENT PIGMENTS
Pearlescent pigment give a sheen and color to products that cannot be achieved by dyes and pigments. Made by depositing titanium dioxide and iron / metal oxide onto synthetic or natural mica in various sizes, shapes, and thickness, pearlescent pigments are translucent and have a smooth surface that easily reflects light. The size, coarseness and the thickness of the pieces determine how shiny the finish will be, with bigger pieces having more glitter and sparkle.
CHARACTERISTICS OF PEARLESCENT PIGMENTS
The lustre of a coating of pearlescent pigment is influenced by a number of elements.
- Size of the Platelets – The mica particle size has a big impact on the lustre, coverage and appearance of the coatings. How fine or coarse the particles also play a role in the power spectral density (PSD) curve of the pigment.
- Concentration of the Pigments – How much pigment is added to the base determines the quality of the sheen it emits. Specified quantities of the pigment are required for the color effect and for adequate coverage and concealment. Too much or too little of concentration can cause the overall appearance to be damaged.
- Orientation of the Platelets – The direction in which the mica is facing determines the reflection and color that the coating will emit. Film shrinkage and coating levelling when the coating dries helps to ensure consistent orientation of the platelets.
- Film Transparency – The optics of pearlescent pigments requires light to pass through the film without any obstruction. Additives that are added to the pigments should also be such that it does not add opacity to the film or reduce the transmission of light.
HOW DO PEARLESCENT PIGMENTS WORK?
The high level of transparency in mica platelets allows white light to pass through it. The titanium dioxide coating on top of the mica platelets have a higher refraction index than mica and light gets refracted and reflected in various angles at contact. This difference in refraction creates a pearlescent effect. In order to derive unique and distinctive artificial colors, manufacturers manipulate the thickness of the metal oxides being used in the pearlescent pigments to achieve refractions of specific wavelengths of light.
WHERE ARE PEARLESCENT PIGMENTS USED?
The shine and smoothness of pearlescent pigments make them popular in various industries.
- Cosmetics Industry – Shimmery, sparkly cosmetics have been in vogue for some time now and the trend does not look like it will go away any time soon, especially on the party circuit. Due to its purity, synthetic mica is regularly used in the cosmetic industry to create bold and intense colors with a distinct lustre and sheen while being kind on the skin.
- Plastics Manufacturing – Pearlescent pigments have strength and stability during processing and can be used in almost any resin including PS, PP, PE, PVC, acrylic, styrene block copolymers, and silicone. Manufacturers of cosmetics prefer to use pearlescent pigments in the plastic packaging of their products to match with the colors of the products in order to make it easier for consumers to recognize the cosmetics from their packaging.
