“Hydrophilic” literally means water-attracting, as such a hydrophilic coating results in water molecules being attracted to the surface. Hydrophilic coatings and treatments are typically utilized to enhance surface lubricity, minimize surface friction, or for applications where having a surface that fully wets out when exposed to moisture is desirable. Most hydrophilic coatings are hygroscopic and will readily absorb moisture when exposed to it. These saturated coatings have significantly reduced friction while wet resulting in drastically reduced pull forces and coefficient of friction.
What applications benefit from a hydrophilic coating?
There are numerous applications in a wide variety of industries that can benefit from hydrophilic coatings. Examples include optical applications, medical applications, & industrial & consumer applications. Medical devices such as catheters and guidewires benefit from having a more lubricious surface. Optical components used outdoors to benefit from having a surface that allows water to evenly wet out allowing for distortion-free optical performance. Numerous consumer applications benefit from having a surface that is more lubricious or prevents the formation of fog on mirrors & glass. In addition, a hydrophilic surface can be utilized for improved fingerprint aesthetic behavior. You may benefit from a hydrophilic coating if any of the following apply to your application:
- Functional issue due to liquid behavior on the surface
- Surface contamination (fingerprints) degrades products aesthetic behavior
- Water droplets/contamination impede optical performance
- The surface is not lubricious enough
- Wettability of the surface is not ideal
- Desire to prevent bubble formation underwater
How are hydrophilic Coatings Applied?
There is a wide range of options for the application of Hydrophilic coatings. Examples include:
Dip Applied Hydrophilic Coating
Dip coating can be utilized to treat large batches of parts which require complete treatment of all surfaces. In some cases masking may be needed to prevent treatment of certain areas. Dip coating can be done manually or via automated process which controls insertion and extraction rates. Upside to dip coating is it is a simple process and allows for large volumes of quickly treated parts. Downside to dip coating is the need to properly maintain the bath concentration, mitigate evaporation & dragout losses, in addition to replacement of contaminated bath materials.
Selective Deposition Hydrophilic Coating
For applications requiring hydrophilic functionalization of only certain areas manual or automated selective spray/deposition can be utilized. A wide variety of applications and nozzle options can support nearly any application and hydrophilic fluid regardless of viscosity.
Spray Applied Hydrophilic Coatings
Spray application is an effective and easy to implement coating process for application of hydrophilic coatings to large surfaces or for high volumes of parts. Spray application is flexible as well as parts can be done in line or in a batch process. In addition, spray processes can be done manually or automated. Downsides to the application by spray are high usage rates due to overspray and also the necessity for masking in some scenarios
Vacuum Deposited Hydrophilic Coatings
Certain hydrophilic treatments are applied via vacuum deposition processes. These are good options for small batches of parts requiring complete treatment. Parts requiring selective treatment can be masked prior to application. The upside to the vacuum deposition process for hydrophilic coatings is repeatability, uniformity of coating thickness, and tight control over coating thickness. The downside to vacuum deposition options is extreme high cost of capital equipment and low throughput due to small batch sizes.
How do you solve your hydrophilic surface issue?
The first step to solving your hydrophilic surface-related issue is to reach out to a proven supplier of hydrophilic coatings. Aculon is a leading B2B manufacturer of easy to apply liquid phase hydrophilic coatings. Rather than providing generic off the shelf solutions, Aculon only works on new programs on a case by case basis optimizing a solution for your application that is truly a perfect fit. Together we can help you make winning hydrophilic products.