Over the years people have invented various ways of reducing labour and increasing productivity and accuracy of doing any particular job. Powder coating an alternate method of painting that has certain advantages and disadvantages over the conventional way. Powder coating solutionsare one of the best inventions as of now because it removes most of the problems that was being faced by the painters originally. Many solutions and elements go into the preparation of powder coating, each serving different purposes.
What is Powder Coating?
Powder coating is like painting, but the dry powder is sprayed onto the surface and then cured at a specific temperature for the powder to set in on the surface. It is more brutal and durable than conventional paint. Powder coating is mainly used on metals like automobile parts, particular hardware, household appliances, etc. Some recent advanced technologies in powder coating help us to powder coat other materials like plastics, carbon fibre, etc.
Powder coating has various advantages over conventional painting that needs a solvent. Powder coating is classified into two types: thermosets and thermoplastics.
- The main difference between the two is that thermoplastics are reversible and reusable as there is no chemical bonding.
- In contrast, thermoset powder forms strong chemical bonding and is not recyclable.
- Thermosets are cheaper than thermoplastics so whichever one works for budget is selected.
Ingredients is the key
Daniel Gustin invented the powder coating process in 1945. When it comes to powder coating, solutions are a bit complex. There are various ingredients in powder coating solutions. Resin, curing agents, post additives, tint pigments, extenders, etc., are the main components used in powder coating. Powder coating will always contain epoxy or polyester, the most common resins.
- Curing agents like Dicyandiamide and primid are used to increase the durability of the coating. Curing agents also help to solidify the powder coating. Another important one among powder coating solutions is the additives. There are different kinds of additives used for various purposes.
- The most commonly used additive is Benzoin which is mixed with epoxy resin. Benzoin helps in reducing the surface tension of the powder. It also minimizes melt viscosity. BYK 356, CERAFLOUR 920, DISPERBYK – 2200, GARAMITE – 7305, etc., are other commonly used additives. Additives have other uses too.
- Getting a hardened finish or producing a Matt-like effect are some of them. Post additives are also an integral part of powder coating. They are also added along with the other powder coating solutions to prevent them from becoming too thick. It helps get the power form.
- Tint pigments are also added, which provides the colour to the coating. Organic and inorganic pigments determine whether colours are dull or vibrant. Extenders are added along with other powder coating solutions, which help to increase durability and also reduce the glossiness of the powder coating. They are also known as fillers.
- All the powder mentioned above in coating solutions is mixed. They are then melted at high temperatures and then cooled. The obtained substance is then grounded into a powder. The heating helps achieve a good finish, and a hard coating is achieved due to the cooling process.
- A variety of ingredients goes into the making of powder coating. Pigments, additives, levelling agents, flow modifiers, curative, several other minors, and significant additives and agents combined with polymer resin are all part of the Powder coating solutions.
- These ingredients play a role in the smooth functioning, durability, and toughness of powder coating and provide a smooth finish to the surface it’s being sprayed.
These powder coating techniques are indeed the best choice when it comes to painting metal. Due to the complexity of the powder coating solutions, there may also be slight disadvantages in powder coating, like it’s hard to control the thickness of a layer or not to get the exact colours that are needed. But we can overcome that by carefully managing and using the powder coating. Apart from these slight disadvantages, they are the best for getting the job done.