Experts pay attention, here is the mechanism analysis of the coating film forming method!

01 preface

Generally, paint is composed of three components, which are film-forming material, pigment and solvent
.
Sometimes it is necessary to add some functional additives to improve its special functions
.
For details, please refer to the article: Introduction to the basic composition of coatings Online coatingol.
com
.
The coating will form a thin film on the surface of the substrate
.
In addition to the certain mechanical properties of this kind of film, some special functions such as decorative properties are also increasingly sought after by people
.
For example: Glow, color, heat, and other special touch
.
Generally speaking, the coating is a kind of flowing liquid at the beginning, and it forms a solidified film after the coating is completed.
The film-forming methods are mainly as follows:

02 Solvent volatilization and hot melt film forming method

Generally, polymers only show better physical properties at higher molecular weights, but they have high molecular weights and high glass transition temperatures.
In order for them to be coated, sufficient solvents must be used to lower the glass transition temperature of the system to make The value of T-Tg is large enough to allow the solution to flow and coat

Powder coatings are also heat-melted into a film: plastic polymers such as polyethylene, polyvinyl chloride, polyacrylate, etc.
can be crushed into powder, and then attached to the surface of the substrate by electrostatic or thermal methods, and heated to Above the melting temperature, the molten polymer viscous fluid is leveled and cooled to obtain a solid paint film
.
The main powder coatings are thermosetting pulverized powder coatings, which are also accompanied by cross-linking reactions in the process of heating and melting to form films
.
The content of powder coatings will be discussed later .

03 Chemical film forming method

After the molecular weight polymer is coated on the surface of the substrate, under heating or other conditions, intermolecular reactions occur to further increase the molecular weight or cross-link to form a tough film
.