Page 67 - Template Tesis UTM v2.0

VIP can be considered as one of the closed mould processes in composite

system in addition to resin transfer moulding (RTM), vacuum assists resin transfer
moulding (VARTM) and compression moulding. VIP is governed by the principles of

the Darcy’s law and use the differential of atmospheric pressure to infuse thermoset
resin into the mould cavity. VIP is highly affected by three variables, which are

permeability of the laminate, resin viscosity and pressure differential inside a cavity in
relation to atmospheric pressure. To perform this process, the materials required

include mould, bagging film, sealant tape, mould release, spiral tube, inlet and outlet

ports, peel ply and dry fibres. For this study, dry fibres involved are E-glass, basalt,
jute and flax.

VIP process was used in fabricating hemp fibre reinforced acrylated epoxidised
hemp oil-based bio resin for mechanical, dynamic mechanical and moisture properties

characterisation. Before infusing, the mixed resin was degassed, and vacuum level was

maintained at 90 KPa using glass mould. After complete impregnation, the wetted
preform was left for 2h for resin pressure distribution, then de-moulded after 24h at

room temperature cured. Finally, samples were continuing with post curing process at
temperature 80 °C (VE resin) and 120 °C (bio-resin) to gain the optimum properties.

[77].

Yenilmez et al. [73] investigated the consistency of the part thickness and
compaction pressure of the composite panels which were fabricated using a VIP

process. The study concluded that the final part thickness depends on the duration of
the initial vacuuming and gelation, resin pressure at specific location as well as resin

shrinkage factor. Petrucci et al. [80] also used VIP for characterising material
properties of basalt hybridisation with flax, hemp and glass fibres on tensile, three-

point flexural and interlaminar shear strength tests. Rodriguez et al. [74] used VIP to

investigate the mechanical properties of natural and glass fibres using unsaturated
polyester and acrylic matrices. In this study, the resin was injected through two

injection points located at the corners and flows to the centre of the mould with the
assist of a vacuum pump. The fibre volume fraction, Vf was kept at 30 %, the moulded

plaques were cured at 60 °C for 2 h, and post-cured at 110 °C for 3h.

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