Control coating brilliance and smoothness with an orange peel and DOI meter
Two key aspects of coating appearance are smoothness and brilliance. Consumers look for a glossy finish from a top quality product, and deviations from this are associated with poor quality or workmanship. DOI (Distinctness Of Image) and orange peel are vital elements of the brilliance and smoothness of a coating. DOI is the measure of the clarity of reflected images on a glossy surface, while orange peel is a description of texture – literally, a finish develops a texture like that of orange peel. An orange peel and DOI meter is a vital tool for optimizing and controlling a coating finish.
In this article we look at the orange peel and DOI meter, how it works, and the companies and products available in the US.
Orange peel and DOI measurement – how it works
Traditionally orange peel was tested uses a series of panels with varying degrees of orange peel as a comparison. Clearly this method is time consuming and not highly accurate. Distinctness Of Image is a measurement parameter developed in order to be able to express orange peel degrees numerically. By measuring the clarity of reflected images you can measure the smoothness of a surface. The higher the degree of orange peel, the less clear the reflections.
When we focus on the reflected image, we evaluate the image forming quality (DOI). When we focus on the surface itself, we see the structural form of the coating (orange peel). Orange peel appears as a wavy pattern on a high gloss surface, and can be made of smaller or larger structures. The visibility of these structures depends on the viewing distance as the human eye cannot detect structures below 0.1mm. However, the effect on the image forming quality of the surface can be seen, which is where DOI comes in.
An orange peel and DOI meter works by simulating visual perception, scanning the surface with incident light at a 60° angle and measuring the reflected light’s intensity. The bands of waviness represent as lighter and darker, and so the machine can measure the size of the orange peel structures. Structures smaller than 0.1mm are registered as “dullness”.
With an orange peel and DOI meter, you can test each layer of coating for surface issues and fix problems before it is too late.
Where to find an orange peel and DOI meter in the US
There are many causes for orange peel – incorrect coating techniques, the wrong viscosity, a mistake in spray painting equipment, too much paint or coating – but with an orange peel and DOI meter you can test for and ensure the quality of your coated surfaces. There are several companies that sell orange peel and DOI meters on the US market, including BYK-Gardner, Ecometer, and Rhopoint. Below we have a list of a selection of the available tools.
If you need an orange peel and DOI meter for your business or project, get in touch! Use the “Request a Quote” button beneath this article and complete the contact form so we know exactly what you need. We will collaborate with our coating partners to find the best instrument for the job.
|Company Name||Orange Peel and DOI Meter||Description|
|BYK-Gardner||Wave-scan dual||For flat and curved areas, the BYK wave-scan dual is the meter of choice in the automotive industry.|
|Elcometer||Elcometer 408 Triple Angle Gloss & DOI Meter||An all-in-one gloss, haze, and DOI measurement tool.|
|Rhopoint||Rhopoint IQ-S||A goniophotometer with DOI and Reflected Image Quality measures.|