How to produce high quality vacuum glass

Vacuum insulating glass,also named as vacuum glass,is new generation energy efficient glass.

In 2022,there’re 2 development trend for energy efficient glass:

For traditional insulated glass, glass manufacturers started to use new spacing materials to decrease glass edge thermal conductivity and ensure longer lifetime of insulated glass.4SG from Kommerling is selling more and more IGU lines specialized in producing TPS and 4SG spacer systems.

For new vacuum glass,factories are also developing new technology to increase its production efficiency,decrease production costs,make it larger and larger to suit more industry requirement,and get more acknowledge of architects and designers.

So,how to produce high quality vacuum glass?

As we all know that vacuum glass production,the key point is edge sealing ,and keep high vacuum degree.Let’s introduce how VIG is produced in China,in the most typical glass solder sealing and low temperature metal sealing.

Glass solder sealing VIG production.

The VIG production with glass solder sealing technology include:

Glass Cutting →Glass Edging → slot works for getters →Placing ceramic frit micro pillars → Tempering→ Glass solder placing →Drying process → VIG process→Getter activation → QC →Packing.

Vacuum Glass-Produced by Zhongteng with glass solder materials

This is typical production process of one-Step VIG production,of course the VIG process include more complex procedures ,such as heating, sealing,and temperature decrease.

Traditional VIG require glass to be sealed first and evacuate the air inside to make it high vacuum degree,while one-Step production seal glass in high vacuum degree environment so its production is much faster and easier.

Advantage of VIG with glass solder sealing process:

• Flexible production,it’s easy and suitable to produce small orders with mixed small sized glass.
• Thestripe shape getter can also continuous absorb the air inside and keep long lifetime.It can also be hidden into the window frame.
• Ceramic frit pillars are applied so the translucent pillars are hard to be noticed.

Disadvantages are also very obvious:

• Glass are always been anneal during sealing process for high temperature over 300℃.
• The glass stability and quality is inferior forglass solder sealing technology reason.

As the video shows the best manufacturer using this tech,other VIG manufacturers that contain vacuum port will have more problem,such as uneven U value,high failure ratio,and problem in transportation/installation.

How HaanGlas VIG is produced.

HaanGlas VIG is produced with low temperature metal edge sealing technology,compared with above mentioned,one more step is required:

Glass Cutting →Glass Edging → slot works for getters → Silk screen glass edge→ Tempering→ Glass sealing material placing → Placing steel micro pillars→VIG process→Getter activation → QC →Packing.

Compared with glass solder one,the difference is:

1. Silk screened sinteringsilver conductive paste which has similar thermal expansion modulus with the metal and help the permanent bonding between glass and the metal materials.

Silk screen process is required before tempering as the screened layer contain silver for bettering bonding between glass and metal-tempered vacuum insulating glass roduction

2. Micro pillars are steel one instead of ceramic frit one.Metal pillars has better elastic modulus and allow larger pillar spacing, 50*50mm,while ceramic one can only support max 40*40mm.

Micro pillars are placed after tempering process,the steel pillars allow larger spacing,HaanGlas VIG pillar distance is 50 by 50mm

3. Low temperature metal edge sealing.It won’t affect tempered glass strength and the unit panels has same strength as monolithic tempered glass.

HaanGlas vacuum glass are fully tempered,after breakage,glass fragments are even and glass has uniform strength

4. One-Step production.There’re other manufacturers also produce with metal edge tech,but HaanGlas is the only one with one step production that removed the vacuum port to keep high vacuum degree and flat glass.

One-step production enables high vacuum degree and no evacuation holes to facilitate installation and better visual appearance

Problems VIG manufacturers are facing

Of course even though VIG production is much better these years,but there’re still many problems every VIG manufacturers facing:

1. High edge thermal conductivity.

As the glass edge coating are removed so glass edge thermal property is similar to same thickness clear glass,which is almost 10 times that of center,so exposed installation will cause higher thermal breakage risks.

Customers have to use VIG+IGU to decrease thermal conductivity and also make glass edge black color as normal.

2. Lack of designing standard and rules.

Different from already mature laminated glass,insulated glass,there’re still no mature rules and standards that can be taken as reference when architects and facade designers want to apply in new buildings.

HaanGlas is our turnkey VIG manufacturer and supplier ,kindly contact us for your next great VIG building.