7/25/2019 Dip 7i

1/1

Dip coatingis an industrial coatingprocess which is used, for example, tomanufacture coated fabricsand condoms. The earliest dip-coated products may havebeen candles. For flexible laminar substrates such as fabrics, dip coating may beperformed as a continuous roll-to-roll process. For coating a 3D object, it may simply be

inserted and removed from the bath of coating. For condom-maing, a former is dippedinto the coating. For some products, such as early methods of maing candles, theprocess is repeated many times, allowing a series of thin films to bul up to a relativelythic final object.

The final product may incorporate the substrate and the coating, or the coating may bepeeled off to form an object which consists solely of the dried or solidified coating, as inthe case of a condom.

!s a popular alternative to "pin coating, dip-coating methods are fre#uently employedto produce thin filmsfrom sol-gelprecursors for researchpurposes, where it is generally

used for applying films onto flat or cylindrical substrates.

Process

The dip coating process can be separated into five stages$

%mmersion$ The substrate is immersed in the solutionof the coating material at a

constant speed &preferably jitter-free'.

"tart-up$ The substrate has remained inside the solution for a while and is

starting to be pulled up.

Deposition$ The thin layer deposits itself on the substrate while it is pulled up.

The withdrawing is carried out at a constant speed to avoid any jitters. The speeddetermines the thicness of the coating &faster withdrawal gives thicer coatingmaterial'.

Drainage$ (xcess li#uid will drain from the surface.

(vaporation$ The solvent evaporatesfrom the li#uid, forming the thin layer. For

volatilesolvents, such as alcohols, evaporation starts already during the

deposition ) drainage steps.

%n the continuous process, the steps are carried out directly after each other.

https://en.wikipedia.org/wiki/Coatinghttps://en.wikipedia.org/wiki/Condomhttps://en.wikipedia.org/wiki/Spin_coatinghttps://en.wikipedia.org/wiki/Thin_filmhttps://en.wikipedia.org/wiki/Sol-gelhttps://en.wikipedia.org/wiki/Researchhttps://en.wikipedia.org/wiki/Substrate_(materials_science)https://en.wikipedia.org/wiki/Solutionhttps://en.wikipedia.org/wiki/Evaporationhttps://en.wikipedia.org/wiki/Volatility_(chemistry)https://en.wikipedia.org/wiki/Solventhttps://en.wikipedia.org/wiki/Alcoholhttps://en.wikipedia.org/wiki/Condomhttps://en.wikipedia.org/wiki/Spin_coatinghttps://en.wikipedia.org/wiki/Thin_filmhttps://en.wikipedia.org/wiki/Sol-gelhttps://en.wikipedia.org/wiki/Researchhttps://en.wikipedia.org/wiki/Substrate_(materials_science)https://en.wikipedia.org/wiki/Solutionhttps://en.wikipedia.org/wiki/Evaporationhttps://en.wikipedia.org/wiki/Volatility_(chemistry)https://en.wikipedia.org/wiki/Solventhttps://en.wikipedia.org/wiki/Alcoholhttps://en.wikipedia.org/wiki/Coating