Mascara tubes, lipstick, caps, closures, perfumes, jars, bottles: when it comes to cosmetic packaging, the metallization is a powerful and convenient technique. It greatly enhances the aesthetics of the product and makes a lasting impression on customers, adding a touch of luxury and sophistication and obtaining uniform surfaces with metallic appearance. In this article, we will explore how cosmetic packaging metallization works.
Phase 1: Part loading and cleaning
During the whole process, the parts are loaded on a tooling fixture (usually a bar) which should guarantee maximum efficiency in number of pieces per bar and should be in good cleaning condition. The parts must be very well cleaned and prepared to receive the coating; for this reason, depending on substrate material and quality, brushing, deionization and flaming (if substrate is glass or PP or other specific material) are usually requested.
Phase 2: Basecoat application
Primer and/or basecoat are applied to promote adhesion and provide a smooth surface for the metallizing and paint finish. There are several methods of application as well as lacquers suitable for metallizing process and different possibilities of curing. In the cosmetic industry, lacquering is usually solidified by UV rays which increase mechanical and chemical resistance and give the possibility to use quite all kinds of plastic material such as PP, PC, PE, PS, PETG, PCTS, ABS.
Phase 3: Vacuum metallization
Metallization is the process of applying thin layers of metal, typically aluminum, onto the surface of non-metallic packaging materials such as plastic or glass. This is achieved through several vacuum techniques, including thermal evaporation or magnetron sputtering, all of which involve depositing the metal onto the packaging surface to create a brilliant, mirror-like finish, with a reflectivity starting from 85%. The thickness of the layer of aluminum is very thin, usually from 70 to 100 nanometers or even less. The choice of technique depends on geometry of pieces, requested productivity, budget, metal to be deposited and, most important, necessity of automatic loading and unloading of the bars.
Phase 4: Topcoat application
Topcoat is applied to enhance resistance to moisture, abrasion, scratching and chemicals and has a functional and decorative function. It can be clear or tinted: every color can be obtained with UV lacquering thanks to the unlimited color range of pigments and lacquer types. Also, the textures can be gloss, matt or satin and special effects, such as glass effect, old-looking texture and gradation effect, can be achieved thanks to special varnish. Additional process as in example pad printing, screen printing, hot stamping or laser can follow. Last but not least, recyclable lacquers make the products environmentally friendly!
