Composite cryo tank development- ISRO initiatives

Composite tanks are light weight and cost effective. Attempts have been made elsewhere, to extend composites for cryogenic tank realization, without employing any additional liner. A technological paradigm shift is required to achieve linerless composite cryo tanks, which includes use of high elongation toughened epoxy system, Out-of-Autoclave curing prepreg system, skirt technology for leak venting, automated fiber placement process for laminated shell surface construction, thin-ply technology for leak tightness, in-situ and embedded health monitoring for continuous health tracking, in-situ NDE technique for inter-layer verification during processing etc. As an initial step, the team has attempted to understand and prove the need for a high elongation resin system, its efficacy at cryo temperatures and its processability to realize filament wound systems. The feasibility of progress in this route has been validated by means of studies conducted in specimen- level trials followed by sub-scale studies.