ADCO Products has developed a new PV sealant and J-Box pottant that is claimed to offer a significant reduction in moisture permeability. The ‘HelioSeal’ PVS 800 is a newly developed, hot-melt pumpable, butyl material designed to seal a module’s back hole (a hole that is drilled through glass to let power wires and conducting tapes through to the J-Box) and to pot the J-Box all at the same time, avoiding corrosion and preventing moisture vapour from passing through to the wire connections.
Corrosion and moisture vapour transmission can greatly affect module reliability – methods for prevention of these factors can improve this reliability and thus return on investment.
Using HelioSeal PVS 800 for both the back hole and potting applications allows PV module manufacturers to maximize protection against moisture. When combined with HelioBond 200 or HelioBond 205 structural adhesive products, it is claimed to provide a single source for all J-Box attachment and sealing requirements. HelioSeal PVS 800 is applied using industry-available hot-melt equipment. Standard hot-melt bulk unloaders are recommended, as they use optimum length heated hoses and a heated platen ram to achieve proper melt rate to allow for required flow rates. HelioSeal PVS 800 does not require hydraulic-assisted ram plates to achieve higher volumes nor does it require vacuum de-gassing. Typical system heat requirements of the hot melt bulk unloader are 275°F – 325°F (135°C – 163°C). Rod displacement or metered gears are both acceptable dispensing technologies. The dispense nozzle temperature range can be 275°F – 325°F (135°C – 163°C). Typical flow rates for this product of 400cc/minute can be reached under these conditions.
HelioSeal PVS 800 is UL listed under QIHE2 having obtained all of the electrical property performance approvals needed for junction box potting. HelioBond PVA 205 is an easily applied, neutral curing, one-part silicone sealant that reacts with atmospheric moisture to form a durable and flexible seal. HelioBond PVA 205 has a high modulus and elasticity for the manufacture of dual seal insulating glass that can be exposed to direct UV as in flush glazed IG Units.