What is the Difference Between Curing and Drying

The key difference between curing and drying is that in the curing process, heat is applied or generated to evaporate the water of the solvents in ink, which leaves the pigments behind on the substrate to provide color, whereas, in the drying process, ink is solidified from liquid to solid.

Curing and drying are important processes that occur after coating a surface with a thin layer of a particular paint.

1. Overview and Key Difference
2. What is Curing
3. What is Drying
4. Curing vs Drying in Tabular Form
5. Summary – Curing vs Drying

What is Curing?

Curing is the process of water or solvents being evaporated from your coating. This process is completely separate from the drying process. Whenever we apply paint on a solid material, the paint goes through a chemical process of binding to the surface. It is not ready to use for everyday use until the paint has fully bonded and hardened, which means the paint is not yet cured.

For example, when a vehicle that had just received a paint job is not suitable to be used in the open and travelling from place to place. This is because the paint is not ready yet. During the process of curing, it is important to be gentle with the surface of the object. Until this complete bonding occurs, the surface is easily subject to scratches or chips and peeling off. During this process, the water in the paint tends to evaporate, and the other chemicals tend to react, causing the paint to bind with the surface. When it is completely cured, the material is then more durable and resistant. Therefore, we can now use the object for everyday use.

There can be several reasons for the requirement of a curing process. For example, in the automotive industry, this often includes paint jobs and coating applications in repairing or improving the appearance of the vehicle. Besides, ceramic coating is an increasingly popular choice that makes car maintenance easier.

What is Drying?

Drying can be described as the application or generation of heat to evaporate the water of the solvents in ink, which leaves the pigments behind on the substrate to provide color. This process is known as evaporation and coalescence. All water-based paints usually undergo drying.

In the first phase, evaporation occurs. During this phase, the volatile liquids evaporate from the paint film in the presence of atmospheric conditions. Usually, water tends to evaporate quickly. But the slower evaporating liquids might be used as well, and these are known as co-solvents. These co-solvents are designed to remain in the paint film for a long time and provide most of the properties that are required prior, during, and after the application process.

The second phase is the coalescence phase. It occurs after the evaporation step. After the majority of the volatile liquids have evaporated, a coherent paint film is formed from discrete particles of a polymer binder that is dispersed in the liquids.

There are ingredients in paints that are necessary for minimizing or eliminating undesirable film defects that become visible when the paint is dry. The additives of a typical paint include dispersing agents, anti-setting agents, and emulsion stabilizers, which are also included in the formulation to aid the manufacture and stability of the paint can.

What is the Difference Between Curing and Drying?

The key difference between curing and drying is that in the curing process, heat is applied or generated to evaporate the water of the solvents in ink, which leaves the pigments behind on the substrate to provide color, whereas the drying process involves the solidification of the ink from liquid to solid. Moreover, curing happens when the paint coating has reached a maximum hardness and 100% dryness, whereas drying happens when the solvent evaporates from the paint coating, leaving the paint dry to touch, but it might not be 100% dry.

Below is a summary of the difference between curing and drying in tabular form for side-by-side comparison.

Summary – Curing vs Drying

Paints are any pigmented liquids, liquefiable, or solid mastic compositions that can convert into a solid film after the application to a substrate in a thin layer. The key difference between curing and drying is that in curing, heat is applied or generated to evaporate the water of the solvents in ink, which leaves the pigments behind on the substrate to provide color, whereas drying involves the solidification of the ink from liquid to solid.

Reference:

1. “Drying Process of Paints.” Dulux.com.au.

Image Courtesy:

1. “Multicolored tempera paints” By Joyful spherical creature – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Painting Wall” (CC0) via Public Domain Pictures.net