Woven Fiber Reinforcement Research Articles

Transverse Strength Evaluation of Light Cured Resin Impregnated Fiber Glass Reinforced Complete Denture

Background: The transverse strength of heat-polymerized denture base resins considerably enhanced by including either metal wires or glass fibers. Moreover, the transverse strength of specimens reinforced with continuous unidirectional glass fibers was significantly higher than that of metal wire or woven fiber reinforcements. Materials and Methods: Acrylic resin specimens had divided into two groups according to the type of material tested (group I: conventional heat cured acrylic resin, group II: resin impregnated fiberglass reinforced complete denture base). Static load on the prepared specimen using universal testing machine. Three points bending apparatus used to position the specimens with 7.5 KN load on each specimen. The three-point bending apparatus consisted of two parallel stainless steel rods away from each other by 50 mm. While the 7.5 KN load was applied centrally by a 10 mm diameter cylindrical stainless steel rod with 5 mm/min speed. Results: The transverse strength values of resin impregnated fiberglass reinforced acrylic resin showed statistically significant higher values (as P < 0.05) than conventional heat cured acrylic resin. Conclusion: that Fibers critical length was a measure of minimum fiber length required for maximum stress transfer within polymer matrix. Working with bisGMA resin, the critical fiber length established for acrylics with increased values.

Viscoelastic Modeling of Responses in the Whole Compaction Process for Woven Fiber Reinforcements

Compaction and the corresponding viscoelastic behaviors of woven fiber reinforcements are essential to determine the mechanical properties of composite components. Current reported works separately studied the viscoelastic behaviors in partial stage of the compaction process. In contrast, here, we propose a uniform viscoelastic model that can describe the viscoelastic responses in all stages. Systematical experiments of carbon and glass woven fiber reinforcements demonstrate the effectiveness of this viscoelastic model. Moreover, the significances of the model parameters and their underlying relations are clearly revealed. The time constants are not equal in different stages due to different roles of fiber friction played. The relationship among time constants in different stages is found and is experimentally demonstrated. Stress constants strongly depend on the initial stress and types of fiber reinforcements. The relationships between stress constants in all stages are also obtained. The proposed theoretical model here provides a potential and promising approach to understand the viscoelastic responses of woven fiber reinforcements in compaction process.

Study to evaluate the Effect of Silane Treatment and Three Different Woven Fiber Reinforcement on Mechanical Properties of a Denture Base Resin

Study to evaluate the Effect of Silane Treatment and Three Different Woven Fiber Reinforcement on Mechanical Properties of a Denture Base Resin

Modeling of heat transfer and unsaturated flow in woven fiber reinforcements during direct injection-pultrusion process of thermoplastic composites

This paper provides a methodology for the modeling of heat transfer and polymer flow during direct thermoplastic injection pultrusion process. Pultrusion was initially developed with thermosets which have low viscosity. But the impregnation becomes a critical point with thermoplastics which exhibit higher viscosity. There are very few reported works on direct thermoplastic impregnation with injection within the die. In addition, the rare studies have not adequately addressed the issue of unsaturated flow in woven fiber reinforcements. The solution proposed here, models the polymer flow through dual-scale porous media. A heat transfer model is coupled to a flow model enriched with a sink term. Specific changes of variables are made so as to model the steady state solution of unsaturation along a continuous process. The sink term, added to the continuity equation, represents the absorption rate of polymer by the bundles. Data were measured on a pultrusion line and micrographs confirmed the modeling strategy with an unsaturated flow approach. The flow modeling coupled to heat transfer of the thermoplastic pultrusion process aims at determining the saturation evolution through the die so as to manufacture pultruded profiles with the lowest residual porosity.

Effect of five woven fiber reinforcements on the impact and transverse strength of a denture base resin

Statement of problem. Fracture strength of denture base resins is of great concern, and many approaches have been used to strengthen acrylic resin dentures. Purpose. This study measured the effect of 5 fiber strengtheners on the fracture resistance of denture base acrylic resin material. Impact strength, transverse strength, deflection, and elasticity modulus values of a heat-polymerized denture base resin (Trevalon), reinforced with glass, carbon, thin Kevlar, thick Kevlar, and polyethylene fibers in woven form were studied. Material and methods. One hundred acrylic resin test specimens reinforced with woven fibers were fabricated. The control group consisted of 20 specimens with no fiber reinforcement. For the impact strength test, a Charpy-type impact tester was used. Transverse strength was assessed with a 3-point bending test by using a screw-driven mechanical testing machine. Ten specimens were used for each test. Results. The highest impact test values were produced by polyethylene-reinforced group, and the lowest values were obtained from specimens containing no fibers. There were significant differences among the test groups, but no significant differences in transverse strength were found. The lowest transverse strength values were obtained for specimens strengthened with polyethylene fibers, which also insignificantly decreased transverse strength of the acrylic resin. Conclusion. The impact strength of denture base acrylic resins was increased with fibers in woven form. Tested fibers did not have a significant effect on the transverse strengths. (J Prosthet Dent 1999;81:616-20.)

Novel Techniques for Manufacturing Woven Fiber Reinforced Ceramic Matrix Composites. I. Perform Fabrication

Abstract Further research and development of the processing science and technology for ceramic matrix composites (CMCs) is essential for the full industrial exploitation of these materials. This paper describes and discusses a novel, cost-effective processing technique for manufacturing CMCs containing 2-dimensional woven fiber reinforcements. The technique relies on the colloidal processing of ceramic sol precursors and the use of electrophoretic deposition (EPD) to impregnate these sols into woven fiber preforms. The fabrication routes for a woven SiC fiber reinforced mullite matrix and a woven alumina fiber reinforced alumina matrix composite have been investigated. The parameters necessary for the formation of dense green body compacts using EPD are described for the two composite systems. Micro structural examination of these compacts highlights the importance of the infiltration and drying stages to the fabrication of crack-free composite bodies. The laboratory-scale results achieved to date indicat...