Resin Film Infusion (RFI)

Dry fabrics are laid up interleaved with layers of semi-solid resin film supplied on a release paper. The lay-up is vacuum bagged to remove air through the dry fabrics, and then heated to allow the resin to first melt and flow into the air-free fabrics, and then after a certain time, to cure.

Resin Film Infusion Application Process
Layers
Basalt Fiber Tech Resin Film Infusion Application Process©2015 - Designed by Lucas Sant'Anna
  • 1Using a Mould, dry fabrics, release paper, resin film, and a plastic bag the product will be created using pressure and vacuum.
  • 2 Basfiber® Fabrics are laid up interleaved with layers of semi-solid resin film supplied on a release paper on the mould. The release paper is responsible to absorb the excess of resin during the process.
  • 3 The Plastic Bag will ensure that a pressure pump will remove all air from the mould resin and fabric.
  • 4 Applying pressure to the fabric and the resin in the mould to assure that no crimp will be created while the vacuum pressure is applied to the mould.
  • 5 Using an air pump while it heats the temperature enough to melt the resin film and impregnate in the fabric, the air is removed from the sealed mould until the pump stops, once is cured the product is removed from the plastic and the mould, all resin excess should stay in the release paper.
  • 6 The Final Product is resin impregnated reinforced fabric composite product that used tangible resources, enabling better costing in the resin and all materials usage.

Resin Film Infusion (RFI) has been used to fabricate composites with continuous unidirectional fabrics and epoxy with low weight fractions of carbon nano-tubes (CNTs) in matrix. An ultrasound-assisted dissolution-evaporation method with thermoplastics or block copolymers as dispersing agents for nano-particles enabled uniform dispersion of CNTs in the resin. Rheological characterization of CNT-filled epoxy revealed that viscosity, and hence processing of the resin remains unaffected as compared to pristine resin at elevated temperatures of subsequent composite manufacturing. Local flow of the modified resin through the sandwiched fabric plies in RFI process as against the global flow in traditional liquid composite moulding processes, made sure that uniform distribution of nano-particles is accomplished throughout the composite. Compressive properties of hybrid composites improved considerably with CNTs at loading fractions as low as 0.2 wt.%.

Materials Options:

  • Resins: Generally epoxy only.
  • Fibres: Any.
  • Cores: Most, although PVC foam needs special procedures due to the elevated temperatures involved in the process.

Main Advantages:

  • High fibre volumes can be accurately achieved with low void contents.
  • Good health and safety and a clean lay-up, like PrePreg.
  • High resin mechanical properties due to solid state of initial polymer material and elevated temperature cure.
  • Potentially lower cost than PrePreg, with most of the advantages.
  • Less likelihood of dry areas than SCRIMP process due to resin travelling through fabric thickness only.

Main Disadvantages:

  • Not widely proven outside the aerospace industry.
  • An oven and vacuum bagging system is required to cure the component as for PrePreg, although the autoclave systems used by the aerospace industry are not always required.
  • Tooling needs to be able to withstand the process temperatures of the resin film (which if using similar resin to those in low-temperature curing PrePregs, is typically 60-100°C).
  • Core materials need to be able to withstand the process temperatures and pressures.