VESTOSINT® stands for high-performance powders manufactured by a special physical process and features a nearly round geometry. Therefore, they are eminently suited particularly for coatings.
Evonik manufactures laurolactam, the monomer of polyamide 12 (PA 12), derived from butadiene. Polyamide 12 has the lowest amide group concentration of all commercially available polyamides, allowing for lower moisture absorption and maintenance of mechanical stability while under conditions of changing humidity.
Properties of VESTOSINT® Polyamide 12 Powders
The coating powder manufactured from the base polymers with technically challenging processes affords other physical, chemical and electrical properties that make it perfect for a broad spectrum of applications:
- high mechanical strength, elasticity and surface hardness
- low water absorption and water vapor permeability
- high resistance even in warm and detergent-containing water
- low thermal conductivity
- good electrical insulation and dielectric strength
- easy to clean
- no surface fouling
VESTOSINT® maintains these properties even at extreme sub-freezing temperatures. VESTOSINT® coated objects are not only protected from abrasion, scratching and impact abuse but also, from chemicals and corrosion. The protective action increases pro- portionally to the layer thickness, up to 500 microns.
Fluidized Bed Coating Process
When metals are coated with polyamides, the positive properties of the two materials are combined. Fluidized bed coating technology is the most cost-effective method for coating preheated, preferably metallic objects with plastics. It consists of a combination of fluidized bed and immersion processes.
With an economical equipment investment, layer thicknesses of 250 - 500 microns are achieved; even coatings of 1 - 2 millimeters are possible. A fluidized bed coating pan consists of the powder container and the air receiver, separated by a porous fluidizing bottom. Oil- and dust-free air flows into the air receiver and passes through the fluidizing bottom in the form of fine bubbles. It transforms the sintering powder to the fluidized state resembling boiling liquid.
The fluidized bed coating powder has a particle size distribution ranging from 30 to 250 microns and is adjusted so as not to produce dust. Metal substrates of any geometry constructed of steel, metal alloys or aluminum can be coated. To do this, dip the pieces in fluidized VESTOSINT® powder. The powder sinters to the surface of the substrate and fuses into a smooth surface thanks to its residual heat. Depending on the desired coating thickness, the pieces are heated to 230 - 450 °C and dipped for 2 - 10 seconds. The process operates without solvent. Materials that change their shape, lose their properties or generate gases during the above described procedure cannot be coated.
Further Processing Methods for VESTOSINT® Powders
The main fields of application of minicoating includes the coating of clips for the undergarment industry and component coating for the electric and automobile industries. The principle of minicoating is similar to that of fluidized bed coating. Hot (small) parts drop into a fluidized VESTOSINT® powder pan. As they fall, the powder sinters to the metallic surface. Subsequently, the objects are conveyed out of the VESTOSINT® container in a vibrating trough and the surface is further smoothed, no matter the shape of the articles being coated.
The warm‑spraying process enables the application of VESTOSINT® powders onto components that require lower thermal impact or more controlled coating conditions. In this method, the powder is gently heated and propelled onto the substrate, where it melts and bonds to the surface. This allows the creation of uniform, high‑quality coatings even on temperature‑sensitive materials. After deposition, the coated parts can be further conditioned to achieve the desired surface finish and mechanical properties.
Product Story
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"Our global team of experts is ready to assist you with all your inquiries about VESTOSINT® polyamide 12 nylon powders and their diverse applications. Contact us to find the perfect solution for your coating needs!"
Peter Altenbuchner
Market Manager Consumer Powders | High Performance Polymers
