Ultra-short pulsed laser welded-and-cut glass support pillars for vacuum insulating glass.

Abstract

Vacuum insulating glass (VIG) has demonstrated competitive Ug-values (heat transfer coefficients) which show promise to further reduce energy consumption from buildings. Support pillars are an essential part of the design as they support the glass panes which would otherwise deform, and potentially collapse, under the pressure differential between the internal vacuum and the external atmosphere, however they act as small thermal bridges which contribute to heat transfer through the panes. The main cause for this is their high thermal conductivity as they are made out of metal. The use of glass support pillars would improve the Ug-value by 10-20% depending on the pillar size and pillar separation. Additionally, a directly bonded glass pillar, made from the same material as the glass panes, without the need for any adhesives, would improve recycling and visual appearance. We demonstrate a new technique for manufacturing glass support pillars using laser welding to bond, and laser cutting to shape the pillar to the substrate glass. We show that these pillars are able to withstand the expected atmospheric compressive force related to a pillar separation of 20 mm with promise for future research.