How automotive and industrial glass coatings work

Glass coatings protect surfaces from water, road debris, heat and scratches. In automotive applications, the right coating improves visibility and reduces maintenance. In industrial settings, it extends the service life of glass components and controls which wavelengths pass through. This article explains the main types of glass coatings, how they work and where they are used.

What is a glass coating?

A glass coating is a thin layer applied to a glass surface to change how it behaves. Depending on the coating type, it can repel water, resist scratches, block heat or filter specific wavelengths of light. The coating chemically bonds to the glass surface or is deposited using a vacuum process.

Most automotive and industrial glass coatings are applied as one of three types: hydrophobic coatings, hard coatings or functional coatings that combine optical and protective properties. The right choice depends on what the glass needs to do and the environment it operates in.

Hydrophobic glass coatings

A hydrophobic glass coating repels water by creating a hydrophobic barrier on the glass surface. Water droplets bead up and roll off rather than spreading across the surface. This improves visibility in rain and reduces the need for windshield wipers at higher speeds.

The effect is measured by the contact angle between a water droplet and the glass surface. A high contact angle, typically above 100 degrees, indicates a strongly hydrophobic surface. Research published in Scientific Reports confirms that super-hydrophobic coatings on automotive glass can achieve contact angles above 135 degrees while keeping visible transmittance above 97%.

Most hydrophobic coatings for automotive glass use fluorinated silane compounds that chemically bond to the glass surface. Once bonded, they form a durable water repellent layer that also resists rain, dirt, road grime and snow and ice. This makes them easier to clean, as rain dirt and contaminants do not stick as easily to the treated surface.

Ceramic glass coatings are a premium type of hydrophobic coating. They use silicon dioxide or titanium dioxide as the active ingredient, which bonds to the glass at a molecular level. Ceramic coatings last longer than standard hydrophobic coatings and offer additional scratch resistance alongside the water repellent properties.

Scratch resistant glass coatings

Glass surfaces in automotive and industrial applications are exposed to road debris, cleaning equipment and mechanical contact. Without protection, this leads to micro-scratches that reduce clarity over time. Scratch resistant glass coatings apply a hard layer to the glass surface that absorbs mechanical stress without scratching. In automotive applications, this is particularly relevant for side windows and rear glass that are cleaned frequently.

In industrial applications, scratch resistant coatings are used on optical lenses, sensor covers and machine vision glass where surface clarity affects measurement accuracy. Hard coatings for these applications are typically applied using PVD glass coating processes, where a thin, dense layer is deposited in a vacuum chamber.

Heat resistant glass coatings

In industrial environments, glass components are often exposed to high temperatures. Heat resistant glass coatings protect the glass surface from thermal stress and reduce heat transfer through the glass. In automotive applications, heat resistant coatings work alongside solar control coatings to reduce the amount of infrared radiation that enters the vehicle cabin. This keeps the interior cooler without darkening the windows.

Infrared absorbing nanoparticles, such as lanthanum hexaboride (LaB₆), are used in functional glass coatings that block near-infrared radiation at very low coating thicknesses. LaB₆ nanoparticles absorb strongly in the 800 – 1400 nm range at doses between 10 and 100 mg per square metre, which keeps the coating thin and visually transparent. For more on how LaB₆ works as an infrared absorbing material, visit our LaB₆ nanoparticles page.

How are glass coatings applied?

Glass coatings are applied using several different methods depending on the coating type and the scale of production.

Liquid application

Hydrophobic coatings and ceramic coatings are typically applied as a liquid that chemically bonds to the glass surface during curing. This method works at low temperatures and is used both in production and as an aftermarket treatment.

CVD and PVD

Hard coatings and optical coatings for industrial glass are often applied using chemical vapour deposition (CVD) or physical vapour deposition (PVD). These processes deposit a thin, dense layer in a vacuum chamber at high temperatures. They produce highly uniform coatings but require expensive equipment and are limited to heat-resistant substrates.

Ink-based coating

A newer approach uses nanoparticle inks that can be applied by spray coating, dip coating or inkjet printing at temperatures below 90°C. This makes it possible to coat glass and other substrates that cannot handle the high temperatures of CVD or PVD. The patented LaB₆ ink platform uses this approach to apply infrared absorbing and wear-resistant coatings directly onto glass surfaces. For more on how ink-based coating compares to CVD and PVD, read our article on CVD, PVD and ink-based coating: what is the difference?

Automotive glass coating applications

Windshield coatings

A windshield coating improves visibility in heavy rain by causing water to bead and roll off the glass. Combined with a scratch resistant layer, it reduces the wear caused by windshield wipers over time. Hydrophobic windshield coatings also make it easier to remove road grime, insects and ice from the glass surface.

Side and rear glass

Side windows and rear glass benefit from hydrophobic coatings for easier cleaning and from solar control coatings to reduce heat build-up inside the cabin.

Automotive glazing

Full automotive glazing packages combine solar control, UV blocking, hydrophobic and scratch resistant properties in a single glass unit. This is standard in premium vehicles and increasingly common across the broader automotive market.

Industrial glass coating applications

Sensor and optical glass

In machine vision, sensors and optical instruments, glass surfaces need to stay clean and scratch-free. Hydrophobic and scratch resistant coatings extend service intervals and maintain measurement accuracy.

Industrial windows and facades

Large industrial windows and glass facades benefit from solar control and heat-resistant coatings to manage internal temperatures and reduce energy costs.

Functional coatings for production

Ink-based functional coatings allow infrared absorbing, conductive or hard layers to be applied directly to glass during or after production, without the need for vacuum equipment or high-temperature processing.

Frequently asked questions

Summary

Automotive and industrial glass coatings protect glass surfaces from water, road debris, scratches and heat. Hydrophobic coatings repel water and improve visibility. Scratch resistant coatings protect against mechanical damage. Heat resistant and infrared absorbing coatings control thermal performance. Coatings are applied by liquid application, CVD, PVD or ink-based processes depending on the application. Ink-based nanoparticle coatings offer a low-temperature alternative to CVD and PVD for substrates that cannot handle conventional processing conditions.