Surface Texture

Question:

I am the Engineering Manager at our plant. We purchase parts and assemblies from many outside sources. Differences in color and texture of outsourced painted parts had always been a problem until our Quality Assurance Department issued paint chip color standards to the suppliers. Our suppliers generally adhere to them very well. However Q. A. is not happy with the differences in the paint textures we receive and we are looking for acceptable levels of variance from our standard. Are there machines or instruments available for measuring paint texture? Can we establish a texture standard like our color standard? S. J.

Answer:

There are mechanical and optical instruments for measuring paint texture. Some of these devices measure DOI (distinctness of image), which is a measure of paint surface texture. There was a time when DOI became a buzz word in the painting and manufacturing industries. DOI became so popular they made a movie. Just kidding, the movie was DOA and it starred Edmond O’Brien. Since DOI, on painted surfaces, has become so important to the automotive and appliance industries, all kinds of measuring instruments have been developed. Use of these instruments will not only enable you to establish a standard, but will also allow your Q. A. Dept. to test incoming shipments of parts and assemblies. Suppliers of these instruments are listed in the 2005 Products Finishing Directory and Technology Guide, and are also available online (www.pfonline.com/suppliers.html).