Resin infusion under flexible tooling

This manufacturing technique implies high costs when used for large-dimension structures, due to the need for hard molds able to bear the resin injection pressure. The RIFT process, a different version of RTM, is performed by replacing one of the two parts of the hard mold with a flexible polymer bag, thus becoming more cost-effective and reducing the contact of operators with the liquid resin and all its 

With low volumes, alternative resins are usually used, such as epoxy or low styrene content polyester. This can show itself to be an effective solution in the short term, whereas in the long run, the process needs to be redesigned to be more cost-effective and to reduce safety risks. 

Impregnation will occur in two different ways according to the conveyor used and the type of fiber bed either in the flow direction perpendicular to the reinforcement disposition or a mixed impregnation with one normal flow and the other parallel to the attitude, very similar to that of RTM. 

The devices used for RIFT are similar to those used for the RTM cycle and for the productive cycle. The following steps should be distinguished  

Mold cleaning Seconding coating Gel-coat application Strengthening 

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RIFT Resin infusion under flexible tooling. 

Vacuum bag moulding for retrofitting is a semi-automatic resin infusion under flexible tooling (RIFT) technique, which allows production of quality composites. In the RIFT process, dry GF are pre-formed in a mould and are taken to the side and attached to the structure. A resin supply is then channelled to the prepreg, and both are enveloped in a vacuum bag. The flow of resin into dry GF (preform) develops the composite material and the adhesive bond between composite and structure as well. 

Vacuum infusion (resin infusion under flexible tooling, RIFT)... 

There are other variations of the RTM, VARTM and CRTM process which belong to the class of LCM processes such as RTM light in which a caul plate is introduced on top of the bag, resin infusion under flexible tooling (RIFT), resin film infusion (RFI) and vacuum injection preform relaxation (VIPR). In addition many of the same processes are known by different acronyms. It is useful to note that as the science base of RTM improved and led to better understanding of the variables and parameters that influence the flow and dry spot creation in RTM, it led to approaches and creative ideas to improve the process and cut down the cost. This learning continues today to evolve new modifications to the LCM family of processes. For example in VIPR one can now introduce flow control effectively to modify the flow front and create a part that is better than the SCRIMP process and is of consistent quality. ... 

Williams C, Summerscales J, Grove S. Resin infusion under flexible tooling (RIFT) A review. Composites Part A Applied Science and Manufacturing, 1996 27(7) 517-524. DOl http //dx.doi.org/10.1016/1359-835X(96)00008-5. 

Kessels JEA, Jonker AS, Akkerman R. Eully 2jD flow modeling of resin infusion under flexible tooling using unstructured meshes and wet and dry compaction properties. Composites Part A Applied Science and Manufacturing, 2007 38(1) 51-60. DOI http //dx.doi.Org/10.1016/j.compositesa.2006.01.025. 

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