- December 10, 2022
- Posted by: admin
- Category: News & Atricles
Epoxy – Resin Free Powder Coating: Pros and Cons, and the Indian Market
Surface coating either for decoration or for protection are composed of primarily two basic ingredients, the binder the film forming material and solid powder dispersed in the media known as pigments. These two partners are acting like body and soul with out which the life is dead in paint.
Epoxy-Resin Free Powder Coating in simpler terms means, the removal of epoxy and then doing powder coating on the surface. Before the implementation of the process, it is vital that one must know about the pros and cons of epoxy and a comparative study of epoxy with polyester and with materials like polyurethane, polyester and other are a must! It is important to have a study of powder which consists of the characteristics like: Types of Powder, Properties / Characteristics of powder and powder defects, and after all the study and intellect one must decide whether removal of epoxy is the need of the hour or not. Powder coating is a type of coating that is applied as a free- flowing, dry powder. The coating is typically applied electrostatically and is then cured under heat to allow it to flow and form a “skin”. Powder coating is mainly used for coating on metals and metal surfaces. The main difference between a conventional liquid paint and a powder coating is that the powder coating does not require a solvent to keep the binder and filler parts in a liquid suspension form. The solvent mentioned, is the solvent grade and usage of solvent is to suspend the pigments and resins and the additives together, there must be no settlement.
The main powder types;
Epoxy: Hardener 91:9, Sp194:6, 94:3.5:2.5 MB68, dicyandiamide: GT7004, YD 903, KD 213 attains the properties of chemical resistance corrosion resistance, surface hardness, mechanical properties, low curing temperature 180°C, but poor UV resistance and when exposed to heat color may change, even 5°-10° caused changes.
Epoxy/polyester: 70:30, 60:40, 50:50 has the properties of flow, great application properties, mechanical properties, low color variation when over cured 180°C, flexibility in formulation and very limited UV resistance.
Polyester +TGIC: 93:7 5501:TGIC and Super Durable Polyester: 88:12-88:15 GH5501:TGIC (warranty 5-10 years) has the properties of outdoor durability, mechanical properties, color stability when over cured 200°C, limited Chemical and solvent resistance and TGIC toxic.
Polyester (Primid Type) +HAA b-hydroxyalkylamide RB301/WH125 96:4, 95:5 owns the properties of being Non toxic in nature, with outdoor durability moderate, mechanical properties are comparatively fine, color stability when over cured, 900d > 180°C, low temp curing, better storage performance.
Polyurethane 70:30,93:7,88:12 : EP 6101,3130J/1530, the properties are outdoor durability excellent Mechanical properties and as well as chemical properties flow and smoothness, and curing temperature is 200°C.
Sublimation Powder EP 6101,3130J/1530; properties being, it is a safe outdoor durability product, good mechanical properties and chemical properties, flow and smoothness and curing temperature is 200°C.
Powder coatings emit zero or near zero volatile organic compounds, powder coatings can produce much thicker coatings than conventional liquid coatings without running or sagging. The overspray can be recycled and thus it is possible to achieve nearly 95%-100% use of the coating. Powder coating production lines produce less hazardous waste than conventional liquid coatings. Capital equipment and operating costs for a powder line are generally higher than conventional liquid lines. These powder coatings comparatively are easy to use, and have advantages just above being profitable in market. The powder coating are not toxic, safe as VOC free for environmental and something that future generations, the upcoming entrepreneurs, suppliers and retailers would happily invest in! Also a wide range of specialty effects is easily accomplished which would be impossible to achieve with other coating processes. While it is relatively easy to apply thick coatings which have smooth, texture-free surfaces, it is not as easy to apply smooth thin films.
Solvent Free Paint means that is VOC Free owns a electro static spray system, where the oven is must and required to reach 220 degrees. It has a very good quality air compressor with no filtering and air drying system required, also thinner is not required. But it is difficult to over coat, pre- heat and do over coating, and striping is difficult and costs more. Though the specialty of Epoxy is that when polyester coating done properly, i.e. 90-100 micron it will pass 1000 hours, and for pure polyester: 70-90 micron and will pass around 750 hours.
Despite having advantages like thinner is not being required, no settling issue of powder , no phase separation observe in powder and controlled Bold structure for control panel industries on direct application with out pin hole still a defect occurs which is know as Faraday cage effect, where the 0owder will concentrate on the edges due to electrostatic lines of force will tend to concentrate on edges and not penetrating to Inside corners or recesses. But this can be resolved by reducing the voltage, electrical field weaken and by increasing the air pressure powder break the electrical field and which will make it enter corners and recesses.
The powder coating market in India, the industry is expected to grow at a CAGR compound annual growth of around 10% during 2021-22 to 2024-25 in value terms. The Indian Paint Industry is today worth over INR 62,000 crores (USD 8 billion), and is the fastest-growing major paint economy the world over, with a consistent double-digit growth over the last 2 decades. It has over 3,000- paint manufacturers, with nearly all global majors present in the country. Small unorganized paint manufacturers primarily catering to the lower end of the price points still maintain a sizeable 30-35% share in the overall paint industry. In the Indian paint industry, the architectural paint out of total 64% share, 36.4% is solvent base paint where as the industrial paint 26% is solvent soluble paint, rest 5% powder. Total paint together the VOC contributing paint quantity is 63.4% and VOC free product is 36.4% Indian paint marker is approximately Rs. 85 billion, out of this 65 % share goes to organized sectors, and 35% share is from SME sector.