Powder coatings are solvent-free enamels that are processed in a 3-step process into a fine coating powder. The powder coating is applied to the part or component by electrostatic spraying equipment or in a tribostatic process. In a subsequent curing process, the powder coating is melted and chemically cross-linked at substrate temperatures of 150°C to 200°C.
The success story of powder coating begins with industrial surface finishes in the 1960s and continues to develop as the technology has many advantages:
- No solvents
- Virtually 100% material utilization
- Easy to process and clean
- Applicable on many substrates
- Protection and decoration
- TIGER Coatings offers the most comprehensive standard range of colors and effects.
TIGER Drylac® powder coatings are solvent-free coating materials consisting of different synthetic resin systems, pigments and special additives for high-quality surface finishing. The basic materials for powder coatings are processed into a fine coating powder in a 3-step production process: premixing, extrusion and milling. Depending on subsequent use, the powder is set to a predefined particle distribution.
In contrast to wet paints, powder coatings do not contain solvents. (Powder Coating Production) The powder coatings are applied to parts by electrostatic spraying equipment or in a tribostatic process. In a subsequent curing process, they are melted and chemically cross-linked at substrate temperatures of 160°C to 200°C.
The history of powder coating begins in the late 40s and early 50s of the past century, at a time when organic polymers in powder form are being flame-sprayed onto metal substrates. Dr. Erwin Gemmer, a German scientist developed the fluidized bed coating process for processing thermoset powder coatings and patented his invention in May 1953. Between 1958 and 1965 literally all powder coatings, mostly only functional applications with thicknesses between 150 µm to 500 µm, were processed using Gemmer's method. The focus was on electrical insulation, corrosion and abrasion resistance. The coating materials used at the time consisted of nylon 11, CAB, polyethylene, plasticized PVC, polyester and chlorinated polyether. At the same time, thermoset epoxy became available, e.g. for dishwashers (PVC), thermal insulation (epoxy), for ship accessories (nylon) and metal furniture (PVC, CAB). Bosch, in searching for a material to use for electrical insulation, developed the prototype for epoxy resin powder.
For the many applications with layers too thick for processing and with the emergence of electrostatic processing of powder coatings a short time later between 1962 an 1964 in the US and Europe, the fluidized bed coating process fell out of use. With electrostatic spray guns from Sames, which briefly gave its name to the process, the next step to electrostatic applications was accomplished. Between 1966 and 1973 the four basic types of thermosets still used today were developed and sold commercially: epoxy, epoxy-polyester hybrid, polyurethane and polyester. The number of powder coating facilities in Germany increased from four in 1966 to 51 in 1970. Since the early 1970s, powder coatings have gradually conquered the world, even initially with nominal growth of the powder coating market until 1980. The facilities were expensive, the layer thicknesses to high for a profitable application, problems changing colors and high enamel temperatures considerably limited the range of colors, effects and substrates.
Since the early 1980s, the powder coating industry around the world experienced continual growth, driven by constant innovation, available commodities, improved formulation know-how and advances in application technology and the development of new applications (e.g. MDF and coil coating); and lastly given the more restrictive environmental protection provisions, these trends are likely to continue in the coming decades.
Association of the Austrian Chemical Industry, ‘Unser Lack und seine Zukunft’ (Our Coating and Its Future).Principles of Powder Coating ‘Grundlagen der Pulverbeschichtung’, Edition, March 1991; updated 2 C. Herrmann, April 1999, internal training documents, TIGER Coatings GmbH & Co. KG.The Powder Coating Institute, ‘Powder Coating. The Complete Finisher's Handbook’, Second Edition, 1999.Industrial Powder Coating, ‘Industrielle Pulverbeschichtung’, J. Pietschmann, JOT reference, October 2002, p. 1Industrial Powder Coating, ‘Industrielle Pulverbeschichtung’, J. Pietschmann, JOT reference, October 2002, p. 1, updated.Industrial Powder Coating, ‘Industrielle Pulverbeschichtung’, J. Pietschmann, JOT reference, October 2002, p. 2.BASF Coatings Technology Manual ‘BASF Handbuch Lackiertechnik’, A. Goldschmidt/H. J. Streitberger, BASF Coatings AG, Münster, Vincentz Verlag, p. 596, 2002; partially updated.