How to Assess the Physical Properties of Paints and Coatings

How to Assess the Physical Properties of Paints and Coatings

The physical properties of paint widely depend on the composition of its pigments. Pigments are further processed to initiate properties like quick drying in humidity, fight against UV light, fluorescence etc. It’s a multi component mixture of binders, surfactants, pigments and solvent or water (also called water borne paints). The properties depend largely on its components. Water-borne paints dry quickly in low humidity, binders gives a smooth finish to the surface. And nowadays, many fancy terms are being used, like cross linking polymers, for getting a waterproof surface. In this post we will read more about cupping machine.

When it comes to automotive industry, paints and coatings are utmost important. It not only gives aesthetics to the vehicle but also protects the outer body from rust. Opacity, scratch resistance, smooth finish, glossy effect are some characteristics that matter a lot. Apart from all these, assessment of elongation of paint after drying is important. A cupping machine can be used for this job.


Why is elongation important?

Dent is a very common sight on a vehicle irrespective of its class. Due to an external force, a depression appears in the body of the vehicle. Be it a crater or elevation, in both the conditions, the paint of the vehicle tends to damage. If the elasticity of the paint is less, it would crack or chip off. This is why it is essential that paint should elongate a bit in case of a dent. If it chips off, it exposes the metal beneath the atmospheric conditions leading to corrosion. And corrosion has the tendency to eat out the material.

How to check elongation of paint?

To simulate the real condition, a cupping machine creates a depression on the sample material using a punch. A rotatory handle moves the punch in the forward direction and keeps on doing so until the paint cracks. One side of metal is painted and one side is non-painted, the punch will apply force on the non-painted side and allows the paint to elongate. The more a paint resist the chipping, the more flexible it is.

It is a table top machine and has become a very important part of the automotive industry as well. Automotive industry cannot take chance with the aesthetics of the products. They have to have quality check department that assures a long-lasting coating of the vehicle. Especially, in the case of commercial vehicles that carry toxic and reactive substances for industrial use are more prone to corrosion of body if paint chips off.