Evaluation of vacuum resin infusion process on selected glass fibre preforms

Mateusz Kozioł, Henryk Rydarowski, Jerzy Myalski

Quarterly No. 4, 2012 pages 285-290

DOI:

keywords: laminate, preform, vacuum infusion, numerical simulation, rising fabric

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abstract The scope of the study is to evaluate the behaviour of exemplary glass fibre preforms during the vacuum infusion process. The reinforcing preforms were prepared from: plain weave crimp fabric, chopped strand mat (with two alternative binders - polyester-appropriate and universal), a unidirectional (UD) fabric and a 3 mm PARABEAMR® 3D rising fabric. ESTROMAL 14 polyester resin was used as the matrix. All the laminates showed a fibre volume fraction in the range of 49÷52%. The permeability analysis was conducted with the use of PAM-RTM software by the ESI GROUP. As the base for the analysis, measured experimental saturation times were used. It is probably the simplest method to determine the permeability of fibrous preforms. The plain weave fabric showed a satisfactory saturation time (less than 9 min for 250 mm preform section) and permeability (5.66・10^-10 m²). The infusion process proceeded in a stable way and the resin front ran uniformly along the whole width of the preform. The chopped strand mat showed a saturation time similar to the plain weave fabric. However, it showed a very long time of saturation (over 46 min for 250 mm preform section) and low permeability (1.06・10^-10 m²) for the universal binder applied to the fibres. The universal binder probably does not react efficiently with terephthalate resins (ESTROMAL 14). The UD fabric showed evident anisotropy in permeability. When saturated along the main fibre strands, the permeability was by half higher than in the case of the plain weave fabric (8.2・10^-10 m²). When saturated transverse to the main fibre strands, it showed a permeability lower by about 40% in comparison to the direction along the main strands (4.65・10^-10 m²). The application of a spreading mesh considerably shortens the saturation time of the UD fabric (less than 1.5 min for 250 mm preform section), but it results in a deficient saturation. The PARABEAMR® fabric showed a lack of the “rising” effect in the VIP process. However, further investigations may show some applications for this structure in pressureassisted technological processes. The study showed that PAM-RTM software may be successfully applied to determine the permeability of fibrous preforms and to analyse the saturation processes. The determined values and trends in the K1 and saturation time are the initial assessment of preforms applicability in the vacuum infusion process.