What is CVD?

Chemical Vapor Deposition - the facts
Squaring off - MSVD vs. CVD
References & Technical Papers

Chemical Vapor Deposition - the facts. Chemical Vapor Deposition (CVD) is an on-line coating technology integrated directly into the float glass manufacturing process. Certincoat^® CVD technology is specifically designed to produce energy efficient pyrolytic coated glass products.

Simplified schematic of pyrolytic coating process.

In the CVD process, reactive precursors are vaporized into a carrier gas stream. The resulting vapor feed is directed to the hot glass surface (generally 600°C) where it reacts to form a ceramic coating. Reaction by-products are exhausted from the coating zone and sent to waste processing.

The advantages of CVD include a high deposition rate and high degree of control. Tuning the process is simply a matter of manipulating the vapor flows in the coating zone. And, because the coating is covalently bonded to the glass surface, the result is a glass coating with unparalleled durability.

At Arkema we have extensive experience with the CVD of pyrolytic coatings on glass. The Certincoat^® CVD System offers the following benefits:

• Longer campaign durations
• Increased flexibility
• Low maintenance
• High yields
• High efficiency

Learn more about the advantages of Certincoat^® CVD technology.

Squaring off - MSVD vs. CVD. Not all Low E glass is the same and not all coating processes are created equal. But judge for yourself - we think the benefit of CVD is clear.

	MSVD [Sputtered]	CVD [Pyrolytic]
Coating	Multi-Layer Coating 1-2 layers metallic Ag 3+ layers dielectric oxide	Multi-Layer Coating Transparent ceramic semiconductor Bi-layer optical undercoat
Application	Off-Line Requires additional processing and time.	On-Line CVD is integrated into the float glass process
Pressure	Operated under vacuum	Atmospheric
Coating Process Energy Usage	High MSVD energy use is 3-9 times greater than CVD.	Low On-line application utilizes heat from the float glass process
Single-Pane Use?	No	Yes
Insulated Glass Units	Coating should be removed from sealant area near edges	Coating does not need to be removed from sealing surfaces
Cutting, Cleaning, & Handling	Easily scratched requires special training and equipment to reduce yield losses	Durable handle with gloves like clear glass
Tempering & Bending?	Difficult	Yes
Storage	Limited shelf life Coating will degrade in 3-4 weeks if exposed to humidity	Store like clear glass Coating will not degrade
Transportation	Easily scratched. Exposure to moisture will damage coating.	Transport like clear glass

References & Technical Papers
Check out these papers for more information on pyrolytic coating technology.

• "Successful implementation methods of atomospheric CVD on a glass manufacturing line." McCurdy, R. J. Thin Solid Films 351 (1999) pp. 66-72.
• "Chemical vapor deposition of coatings on glass." Gordon, R. Journal of Non-Crystalline Solids 218 (1997) 81-91.