The PPA 571 coating protect metal fencing from corrosion for 15 years

Comparing Powder Coating and Paint

Posted on: February 3rd, 2017 by byersbushblog

Two of the most common choices for coatings and restoration are powder coating and paint.  Each has its own benefits and people have their own reasons why they prefer one over the other.  However, is one really better than the other?  You decide after this general comparison.

Overview

The value of coating especially in the medical, construction, automotive, aerospace and electronics industries is priceless.    Aside from improving the overall appearance, coatings help increase the strength and durability of the metals.

The dominant choice before was to use paint as coating, but just a few years ago, powder coating began to rise as the more popular option.  In fact, over 15% of the total industrial finishing market relies on powder coating because it presents improvements over liquid paint coatings in terms of resistance to:

  • Moisture;
  • Chemicals;
  • Impact;
  • Ultraviolet light; and
  • Extreme weather conditions.

Powder Coating Application

Normally there are two ways that powder coating is applied.  The process can either be with thermoplastics or thermoset polymers that are applied as free-flowing dry powder.  What is the difference between the two?

With thermoplastic, the powder melts and flows as heat is applied to the material.  It retains its chemical composition even as the powder cools and solidifies.  On the other hand, thermosetting chemically cross-links with the other reactive components resulting in the changing of the chemical structure of the cured coating.  The thermoset powder coating will also melt as it is exposed to heat.

Unlike thermoplastic, thermosetting remains stable in heat and will not revert to its liquid state when reheated.  Thermoset can also be sprayed on to create thinner films that give off a better appearance compared to thermoplastic coating.

Powder Advantage

Did you know that powder coatings are suitable replacement for paint coatings even on metal household appliances as well as tools, office furniture, and all types of vehicles including its parts?  Is there any difference between the conventional liquid paint and powder coating?  Basically, the main difference lies in the fact that powder coating does not require solvent to hold the binder and filler while in liquid suspension form.

With powder coating, electrostatic spray deposition (ESD) is normally used together with curing by heat.  This presents several advantages compared to conventional liquid paint coating, like:

  • Unlike paint coating, powder has little to no volatile organic compound (VOC) emission;
  • Powder coat finish is more durable compared to conventional paint;
  • Thicker coatings can be achieved with powder coating and does not have running or sagging problems;
  • 100% powder coat usage is possible because overspray can be recycled;
  • Finished surface appearance is more uniform with powder coat; and
  • Specialty effects can be done easier with powder coat compared to liquid paint or other coating process for that matter.

Manufacturing

The particle sizes for powder coating range from 30 to 50μm with glass transition temperature of 200 degrees.  This means that the manufactured particle sizes of powder coating can deliver more efficient coating results.

Depending on the particular application that you choose, the film buildup can be more than 50μm if you want to have a smoother coat.  Some manufacturers prefer to have a slight orange peel effect because it helps to hide some defects on the metal material that may have been caused during the manufacturing process.

As for the surface texture, differences may happen due to the difference in curing kinetics or the visco-elastic properties, which will result in creaking noises as the coated surfaces begin to experience some strain.  The solid and fluid characteristics of powder coatings must be determined prior, during, and after the material has been subjected to curing.  This helps to understand how different formulations can work to achieve a specific result from the process including the needed application for the finished coat.

To get the most benefits from powder coating, you need a provider that has extensive experience in the industry like Byers Bush Powder Coating. Contact us to know the benefits of powder coating in protecting your important equipment against rust than paint does.

Comments are closed.