ポリエチレンフィルムの成形方向及び微小しわと破壊メカニズムの関連性評価

抄録

The use of super pressure balloon (SPB) is currently attracting attention as an inexpensive high-altitude observation technique. Through a flight test of a newly developed SPB, it was found that the balloon envelope made of polyethylene film is damaged at the time of balloon launch to yield hundreds of slits with creep bands around the edges. In this study, we investigated a possibility if the damage is caused by tiny deficits on the balloon envelope film. Static tensile tests of specimen with micro wrinkles or scratches were conducted. It was found that the specimen with microscopic wrinkles showed no difference, however, those with micro scratches showed 30% and 15 % smaller values in breaking strengths and breaking lengths, respectively. Since the creep of the broken specimen were not limited to their broken edges, we consider that the deficits on the balloon envelope are not directly related to the slits found in the flight test of the SPB.