Gerold’s HMA-system automatically applies liquid butyl (hot-melt) for edge-sealing of thin-film modules, replacing the need for butyl tape, which has limiting use factors in high-volume production applications. Gerold claims the HMA-system offers more economical packing drums, less waste, and improved product quality.
The overall objective is better encapsulation properties of the module. This brings about improved cell protection, with prevention of corrosion thanks to blocking of moisture vapor ingress. It may be stressed that butyl has a very low water vapor and gas permeability, significantly more favorable than with EVA or PVB. However, frameless thin-film modules edge-sealing is usually performed by means of butyl tape, which has certain pitfalls in regards to automation, cycle time, small lots, and material utilization.
The HMA-system automatically applies liquid butyl (hot-melt) for edge-sealing of thin-film modules. The advantages of liquid butyl application are use of more economical packing drums, less waste, and improved product quality. Furthermore, butyl bead acuity and repeat accuracy are more favorable. Another valuable feature is available when adding encapsulant sheeting and lay-up to bulk butyl dispense, both being incorporated in the HMA+-system. This is sequentially performed when upgrading the HMA-system accordingly. The encapsulant is fed from a roll and automatically placed onto a cutting table where it is sheeted with perpendicular and longitudinal cuts. Even punching for contact tab feed-through holes is performed, if applicable. A repeat-accurate pick-and-place device transfers the sheeted encapsulant onto a centered substrate and places it into the butyl frame. A third process step, dubbed the HMA++-system, can handle glass-glass-modules. Line takt time governs whether this is performed in the same station as encapsulant lay-up or in a third back-to-back station, provides greater versatility.
Liquid butyl (hot-melt) edge-sealing of thin-film modules.
Gerold's HMA-system features a drum un-loader with drum redundancy. Depending on system configuration one or two dispenser(s) are utilized. The dispenser bridge is a gantry mechanism with servo-controlled X- and Y-movement. The distance between dispenser and sometimes warped substrate surface is monitored by means of laser sensor. Butyl is applied in accordance with the settings for butyl geometry and positioning. For quality control laser sensors monitor the butyl bead.