apdude
Dec 01, 2004, 11:11 PM
Need to make large envelope, have called around and most companies have large minimums. Urethane seems to be the best choice for my application. Was considering mylar (metalized nylon) material but too fragile for outdoor use, also thought of a nylon cover for it. This however raises the complexity and it seems urethane will stand up to more abuse like over inflation and rough handling. As for helium retention urethane I’m told is very close to mylar. I tried polyethylene and it was easy to heat seal but poor helium barrier. Does anybody know if urethane heat seals easily? Also was looking at Seattle fabrics site at polyurethane coated nylon which might work but the urethane coating from a sample I got was pretty thin. The blimps made commercially are of 3.5 mil stuff and sealing thousands of holes through the nylon/urethane fabric does not look promising. But maybe I could after sewing glue the seams together? Wow I really can’t seem to find an easy way to make an outdoor envelope. Maybe someone could help me?!?!?!?!?!