Accession Number : AD0749880

Title :   An Evaluation of Fiber Reinforced Films used in High Altitude Balloons,

Corporate Author : STEVENS INST OF TECH HOBOKEN N J DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Alexander,Harold ; Agrawal,Purushottam

Report Date : FEB 1972

Pagination or Media Count : 79

Abstract : Dacron fiber reinforced mylar films of 2 basically different fiber geometries are analytically and experimentally investigated for use in high altitude balloons. These are the so called 'leno' film, produced by laminating a rectangular matrix of interwoven scrim fibers to the mylar film and the so called 'FTL film produced with longitudinal fibers criss-crossed by diagonal fibers at some angle to the longitudinal direction. Experimentally, the durability of the film-fiber bond when subjected to oscillation at low temperatures, the mechanical properties of the mylar film, the mechanical properties of the dacron fibers and the strength of seals at low temperatures are investigated. Analytically, the most suitable arrangement of the fibers and the optimal angle for the 'FTL' film diagonal fibers is determined and safe stress (failure) envelopes are constructed for 'leno' and 'FTL' films. From theoretical grounds, a 60 degress 'FTL film is the most desirable reinforced film for balloon use. However, the 'mechanical integrity' of the material seems to be an overriding factor in the ultimate strength. (Author, modified-PL)

Descriptors :   (*REINFORCED PLASTICS, MECHANICAL PROPERTIES), (*BALLOONS, REINFORCED PLASTICS), POLYESTER PLASTICS, DACRON, BALLOONS, REINFORCING MATERIALS, FAILURE(MECHANICS), COMPUTER PROGRAMS, FILMS

Subject Categories : Lighter-than-air Aircraft
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE