Fast and effective large-area cleaning and activation of float glass with improved micro-uniformity by atmospheric plasma surface processing
Ambient air atmospheric plasma generated by diffuse coplanar surface barrier discharge (DCSBD) was studied for in-line surface treatment of float glass. Extremely high DCSBD plasma power density and uniformity, even at a very short plasma exposure time 4 seconds (i.e., treatment speed 2 cm/s), resulted in effective surface cleaning and activation of a glass surface. The effect of plasma studied on both tin- and airside of float glass revealed effective cleaning of glass with significantly improved micro-uniformity of glass surface also in comparison with standard “wet” chemical cleaning protocol. As will be shown, a clean and uniform surface after ambient plasma treatment plays an important role in glass bonding. The improved micro-uniformity, together with increased adhesion properties, may eliminate local weak points that can initiate delamination and the subsequent formation of cracks in laminated glasses and thus lead to performance improvement of, e.g., laminated safety glass products. The capability of DCSBD plasma to activate the glass surface with a high surface density of surface hydroxyl species and apparently also the uniformity of their surface distribution was also demonstrated for the enhancement of the initial film formation during the deposition of thin and ultra-thin coatings on glass, e.g. by the atomic layer deposition technique. These results have huge application potential since the DCSBD plasma with unique scalability, safety and energy efficiency can be easily integrated into commercial flat glass processing lines.
Large area atmospheric plasma surface processing of PVB and Ionoplast interlayers for performance improvement of laminated glass
Polyvinyl butyral (PVB) is probably the most commonly and traditionally used elastomeric interlayer for laminated glass (LSG). For high-demanding applications, such as stairs, overhead glazing, and railings, the application of structural interlayers of high stiffness, e.g. SentryGlas Ionoplast, increases the safety of the laminated glass. However, Ionoplast interlayers require some special processing. For example, in the case of multi-ply laminations, a chemical treatment of glass by a primer is needed for proper adhesion to the air side of the glass. It is well verified that the adhesion between the PVB-based interlayer and the glass is mainly generated by the formation of hydrogen bonds between the hydroxyl groups of the two materials. Ambient air atmospheric plasma generated by diffuse coplanar surface barrier discharge (DCSBD) was studied for surface activation of PVB and SentryGlas Ionoplast interlayers and glass. The carried-out experiments show a very significant 60 % growth of average breaking force observed in the bending tests of LSG laminated using the plasma-activated glass and PVB film. In the case of SentryGlas Ionoplast interlayer, it was studied if plasma surface treatment can enhance the adhesion to the air side of the float glass. The results show the potential of DCSBD atmospheric plasma technology for the activation of interlayers considering that the DCSBD plasma sources can be easily integrated into commercial lamination lines.