Numerical simulation of double-bag progressive compression method of resin delivery in liquid composite moulding.

An improved technique of resin delivery, called double-bag progressive compression method (DBPCM), has been developed to manufacture composite parts associated with the vacuum infusion (VI) process. During resin infusion, both bags are pulled upward by the vacuum and the flow resistance offered by the preform is reduced. After the completion of resin infusion, the vacuum on the segmented bags are progressively released to atmospheric pressure allowing the inflated bags to squeeze the surplus resin from the saturated preform. During progressive compression, the dry preform is kept loose and resin easily flows into the preform interstices. Heated air can be utilised at the appropriate compression segment. After the entire preform is wetted, the post-filling stage is carried out to obtain a uniform thickness of the component. This paper describes the numerical results of DBPCM complete filling process in finite difference analysis. The typical VI process is also modelled for comparison purpose. [ABSTRACT FROM AUTHOR]