Quality Evaluation of Resin Transfer Molded Products

Abstract

The present study introduces a new procedure to evaluate the quality of composite products using the graph theoretic approach, and a composite screw rotors process is considered (manufactured by the Resin Transfer Molding (RTM)). The composite product coming from the manufacturing processes must have good surface finish and high quality without any defects. There are several factors which affect the quality during design and manufacture of the RTM products like screw rotors. These factors form a quality digraph based on the interactions existing between them. Hence, we considered the quality digraph by defining fuzzy crisp scores for the degree of interactions between the factors. A quality index derived from quality permanent function is helpful for quality inspectors on the shop floor to decide whether the product is within benchmark limits. The benchmark limits obtained for the composite product, manufactured by the RTM process by considering the strong and weak interactions existing between the factors defined for quality, are considered as upper and lower bounds in deriving the indices. Therefore the present work proposes a quality index, which is a useful numerical index for quality assurance groups to take proper decisions on the shop floor for the manufacturing process adapted to composites (composite molders).

Effect of process parameters on the surface quality of air cushion method

“…The quality evaluation of RTM parts was investigated. [1][2][3][4] Sreekumar et al 1 reported that the tensile and flexural behavior was a function of fiber length and fiber content for sisal fiber reinforced polyester composites. Palardy et al 2 investigated the effect of low profile additives, injection pressure, temperature gradient, filler content, styrene content, and gel time on the surface finish of glass fiber polyester composite panels.…”

“…Palardy et al 2 investigated the effect of low profile additives, injection pressure, temperature gradient, filler content, styrene content, and gel time on the surface finish of glass fiber polyester composite panels. Babu et al 3 proposed a new procedure to evaluate the quality of composite products using the graph theoretic approach. Kaynak et al 4 investigated the effects of preheated mold temperature, initial resin temperature, and vacuum assistance during resin injection by ultrasonic inspection, mechanical tests, and scanning electron microscopy.…”

“…The quality evaluation of RTM parts was investigated. 1–4 Sreekumar et al. 1 reported that the tensile and flexural behavior was a function of fiber length and fiber content for sisal fiber reinforced polyester composites.…”

Experimental RTM manufacturing analysis of carbon/epoxy composites for aerospace application

“…The effect of vacuum on vent gates had already been proven to enhance composite mechanical properties by removing all remained air from preform and assisting the resin flow front 6 . This is an important parameter to obtain high quality composites amongst more fifteen listed by Babu et al 7 . Moreover, the author mentioned the decision of the parameter, which is extremely dependent on the materials to be processed, as well as the mold features.…”

Variable cavity volume tooling for high-performance resin infusion moulding

“…Owing to the increased pressure gradient over long distances and the low permeability of dense fibre reinforcements [11,13], the infusion of large components is excessively slow, and can lead to components with high void contents [1], which can reduce the strength of the composite, and particularly the interlaminar shear strength [2]. The use of higher resin injection pressures and multiple inlet ports has been investigated to achieve higher infusion rates [11,14], although higher flowrates can result in movement of the fabric 'fabric wash' and deformation of the fabric structure [15]. A number of process modifications have attempted to mitigate this problem, including Seeman composite resin infusion moulding (SCRIMP) [16] and vacuum-assisted RTM (VARTM) [17,18], both of which employ a resin porous layer to encourage resin flow longitudinally over the component area.…”