Conclusion and future trends in VARTM

As discussed in this chapter, a VARTM prcx ess is affected by many fundamental factors such as resin viscosity, fiber preform compaction, fiber preform permeability, resin cure kinetics and temperature control. Flow modeling and curing process modehng can help one to avoid these potential problems during the resin infusion and the curing cycle. 

Due to the flexible vacuum bagging system used in VARTM, a composite part manufactured by VARTM could have a thickness non-uniformity issue. Generally, better thickness control (i.e., preform compaction relaxation) can be achieved during the post-mold filling process if one allows enough time for the excess resin to be completely vented out from the resin saturated fiber preform with all resin inflow gates closed. Under such a scenario, the whole fiber preform could be uniformly compacted to its compaction limit (or fiber volume fraction limit) under the pressure difference between the environmental pressure and the vacuum pressure. The preform compaction relaxation can either be measured from experiments or predicted by numerical simulation tools. 

The VARTM process has a great potential to be used in many new applications. It has been recognized as one of the compatible processes for manufacturing green FRP and nano-enhanced FRP. The versatile VARTM process has also been well accepted in many emerging applications that use FRP parts many new variations of VARTM have been developed for cost-effectively manufacturing larger and more sophisticated composite parts with improved success rate and quality. 

The advantages of the VARTM process including its flexibility, versatility, scalability and cost-effectiveness have been well aligned with the future trend of FRP composite structural applications in aerospace, marine, automotive, infrastructure, wind energy and defense industries. Many process 

---