User:MatthewUCSB/sandbox/Anti-Scratch Coating(Draft)

Anti-Scratch Coating is a type of protective coating that when applied to a substrate (surface) provides resistance against scratches. Scratches are the marks left in a object following scratching. Anti-Scratch Coatings share similar mechanical and chemical properties such as high elasticity, hardness, and low friction. However, in spite of shared properties, Anti-Scratch Coatings can differ greatly in material composition. Ranging from carbon base to metal based. Like coatings in general, Anti-scratch Coatings are made up of thin film ranging from nanometer to micrometer. Creating this thin film requires a solvent (dissolves substances), chemical additives/pigments and a resin polymer structure. Adhesion of Anti-Scratch Coating to a substrate is done through methods such as deposition, Spraying and roll to roll. Commercially, Anti-Scratch Coatings are most commonly used in the automotive, optical, plastics, and technology sectors.

Overview of Scratches
Scratches are small permanent cuts to a surface of a object that occur as a result of scratching. Scratching occurs when a hard and more pointed object comes into contact with a softer object. Scratching is a form of Abrasion, which is the wear of a object due to stress from mechanical (physical) forces. The change in structure as a result of scratching and other forms of Abrasion is called Deformations.

On the atomic level, Scratching causes two atomic planes to slide pass each other resulting in dislocation, the movement of atoms planes into new weaker positions. In the case of Scratching, the weaken atomic planes causes the object to be more prone to wear and the potential that future cuts can reach the internal structure of an object, which will decrease the lifespan of a product.

An objects resistance to scratching can be shown using the strain rate equation (measures how much stress a object can tolerate before damage) and the Archard wear equations.(which shows that a rougher surface in more prone to scratches due to Friction)

Note that these equations can not be applied with particles at the nano-level, due to an very different physical environment at this level, which is a reason certain anti-scratch coats contain nano-sized particles.

Testing a object resistance to scratching is done with a scratch specific versions of the strain test.

Properties of Anti-Scratch Coating
Anti-Scratch Coating must (1) contain properties known to provide Scratch resistance and (2) allows for the adhesion of a coating to a substrate, and meet necessary decorative requirements.

Hardness
A Hard object dose not break easily. Anti-Scratch coatings are hard.

Elasticity
Elasticity is the ability of a object to return to its original form after being impacted by a object. Elasticity is similar to flexiblity. Anti-Scratch coatings contain high Elasticity.

Friction
Friction is a type of force that slows an object down. Anti-Scratch coatings contain low Friction. Low Friction objects can be characterized as smooth

Adhesion
Adhesion is the ability of a object to bond on something.

Common Components of Anti-Scratch coating
(metals, Alloy,refractory components oxides, nitrides,carbides), intermetalic compounds, polymers

surface coatings

Blinders (resin)
The name of a coating often refers to the special type of Blinder used. Blinders hold the material in a cohesive manner.

Blinders are largely organic polymers. (https://pdhonline.com/courses/m223/EM%201110-2-3400_Chapter4.pdf)

mposite materials consisting of pigment particles and other additives dispersed in a continuous matrix of polymer

=== (Extender) pigments === Anti-starch coating contains functional pigments called Extenders pigments. Extender pigments when dispersed in the matrix (structure) of the resin enhances the functional properties of a resin. Anti-starch coating extender pigments specially contain anti-starch properties.

metals, Alloy,refractory components oxides, nitrides,carbides

Additives (Defoamers)
Additives are tiny particles that often make less than 1 percent of the coats volume, that are added in a solvent during the coat formation process for maximum coat performance.

Coating formation Process
Coats can be applied with brushes, spraying, and by various industrial techniques. The type of process that can be used depends on substrate and the coating materials. Coats are formed when a liquid or gas is added to a solid substrate. Many processes use deposition, which turns gas particles into a solid coating.

Solvents are used during the coating formation to dissolve additives and blinders. Solvents evaporate after curing.


 * Vapor deposition: A film coating of gas particles are added to a substrate


 * Chemical vapor deposition(CVD) (Chemical vapor deposition - Wikipedia)


 * Physical vapor deposition(PVD)(Physical vapor deposition - Wikipedia)


 * Nanoparticle deposition(Nanoparticle deposition - Wikipedia) The process of creating a coating by adding nanoparticles to a substrates


 * Plasma deposition


 * Chemical and electrochemical techniques


 * Spraying


 * Roll to roll coating processes


 * Physical coating processes.