Powder Coating Properties

When an automotive OEM looks for coatings with high-value perceived surfaces, many different test methods are used to describe the visibility of a scratch. A short overview to summarize different scratch effects follows: Scratch− a type of friction-induced damage in which a sharp object cuts the surface of a polymeric material. Abrasion− a phenomenon caused by the mechanical action of rubbing, scraping or erosion. Mar− friction-induced damage in which the material surface is compressed, causing a marking that changes theRead More …

Durability is a term applied to the various changes in appearance and functional value of exposed pigmented powder coatings. It includes all aspects of exterior serviceability, such as retention of color, retention of gloss, chalking, adhesion and film integrity. The initial effects are usually caused by degradation of the organic binder on exposure to sunlight, moisture, temperature change and environmental pollutants. Chalking occurs as increased amounts of organic binder are removed from the surface of the film, leaving behind exposedRead More …

The selection of coating for erosive wear is dependant on the severity and type of erosion. For solid impingement erosion at a shallow angle of attack where the wear is similar to that of abrasion, high hardness coatings are required. For solid impingement angles near 90 coating toughness becomes more important. For cavitation and liquid impingement generally, a coating with good surface fatigue resistance is needed. The following coatings are commonly used: Cermet coatings like tungsten carbide/cobalt Chromium carbide/nickel chromiumRead More …

Thermal spray powder coatings have and are used in a very broad range of wear resisting surfaces and for the repair of wear resisting surfaces. The main advantage being that thermal spray coating can provide the surface properties and the component substrate material can be chosen from the bulk requirements be it strength, weight or cost without the need to consider it’s inherent wear resistance or other surface properties. Selection of the best coating for an application is not oftenRead More …

Strength Powder Coatings generally have poor strength, ductility and impact properties. These properties tend to be dictated by the “weakest link in the chain” which in coatings tends to be the particle or grain boundaries and coating/substrate interface. Coatings are limited to the load they can carry, and thus require a substrate for support, even then, coatings are poor when point loaded. Internal tensile coating stresses generally adversely effect properties. Effective bond strength is reduced and can be destroyed byRead More …

Poor adhesion is usually related to poor pretreatment or under cure. Undercure -Run an electronic temperature recording device with a probe on the part to ensure that the metal temperature reaches the prescribed cure index (Time at temperature). Pretreatment – Perform regular titration and quality checks to avoid a pretreatment problem.Surface preparation is probably the cause of the poor adhesion of the powder coating powder. Not all stainless steels accept phosphate pretreatments to the same extent; some being more reactiveRead More …

For many reasons including environmental speaking,excellent performance ,high productivity and economics application,powder coatings have been used more and more since the 1970’s. It is clean,almost zero VOC. Additionally powder coatings provide easy clean up without harmful solvents and harmful waste. Over-sprayed powder can be recycled and reclaimed for greater economic savings than liquids paint.It reduce the cost of labor to coat products as much of application is automated.Powder coatings can not be modified at the clients site,thus eliminating inconsistency of products.Read More …

FINE PARTICLES Lower film builds Can blind cartridges and filters Migrate from part into exhaust Reduced fluidization properties Smoother films Absorb moisture more readily COARSER PARTICLES Higher film builds Increased Faraday penetration Increased fluidizaion properties

1.Poor Mechanical Properties and Chemical Resistance Cause: Too high or Too low curing temperature or time Solution: Confirm and check with powder coating supplier Cause:Oil,grease,extrusion oils,dust on the surface Solution:Optimize pretreatment Cause:Differing materials and material colors Solution:Insufficient pretreatment Cause:Incompatible pretreatment and powder coating Solution:Adjust pretreatment method,consult powder supplier 2.Greasy Surface(Haze like film on the surface which can be wiped off) Cause: Blooming effect-white film on the powder surface,which can be wiped off Solution:Change powder coating formula,increase curing temperature Cause: Insufficient airRead More …