Accession Number : ADA304696

Title :   Investigation of Kevlar Fabric-Based Materials for Use with Inflatable Structures.

Descriptive Note : Contractor rept.,

Corporate Author : SHELDAHL INC NORTHFIELD MN

Personal Author(s) : Niccum, R. J. ; Munson, J. B. ; Rueter, L. L.

PDF Url : ADA304696

Report Date : APR 1977

Pagination or Media Count : 89

Abstract : Although tethered balloons have been in use for over a century, the past decade has produced the greatest increase in the sophistication and complexity of these vehicles and considerable related technology has evolved. Recently developed, high-strength materials for hulls, fins and rigging have made a major contribution to improved windward performance. The new DuPont organic fiber, Kevlar, offers further performance gains. Design, manufacture and testing of laminated and coated composite materials incorporating a structural matrix of Kevlar is reported in detail. The practicality of using Kevlar in aerostat materials is demonstrated and data are provided on practical weaves, lamination and coating particulars, rigidity, strength, weight, elastic coefficients, abrasion resistance, crease effects, peel strength, blocking tendencies, helium permeability, and fabrication techniques. Properties of the Kevlar-based materials are compared with conventional Dacron reinforced counterparts. A comprehensive test and qualification program is discussed and considerable quantitative biaxial tensile and shear test data are provided. The investigation shows that single-ply laminates of Kevlar and plastic films offer significant strength-to-weight improvements, are less permeable than two-ply coated materials, but have a lower flex life. Creasing causes a significant loss in strength for Kevlar laminates. Further research is proposed to reduce the inherent rigidity of the experimental laminate material. Multiaxial textile constructions of Kevlar such as triaxial weaves or parallel, nonwoven yarn arrays laminated to film gas barriers appear to be potential fabrication techniques of considerable merit. Laminated and coated composites Kevlar and aerostat materials Multiaxial textile construction Potential fabrication techniques. (MM)

Descriptors :   *LAMINATES, *POLYAMIDE PLASTICS, *INFLATABLE STRUCTURES, STRESS STRAIN RELATIONS, PERMEABILITY, COMPOSITE MATERIALS, ELASTIC PROPERTIES, FABRICATION, COATINGS, HIGH STRENGTH, TEXTILES, YARNS, BALLOONS, TETHERING, PEEL STRENGTH, DACRON.

Subject Categories : Laminates and Composite Materials
      Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE