الفهرس 
Reaction injection molding(RIM)
Experimental WorkOnly 14 pages are availabe for public view
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Abstract
Sandwich materials is one of the most commonly used in all applications due to lightness, durability and reliability with proper strength, toughness and rigidity. However, in recent times their use has increased significantly because of their widespread in structural applications. Structural sandwich panels generally used in Egypt comprise polyurethane foam core and high strength flat steel faces bonded together using separate adhesives by reaction injection molding technique. Previously, polyurethane (PU) Foam core was sandwiched with same thin two faces material.
In this work, the Metallic-PU and Hybrid-PU sandwich composites were prepared by hand lay-up technique. Metallic-PU sandwich composites contained commercial purity Aluminum (Al) or Galvanized steel sheets (G.S) with different thicknesses (0.5,1&2 mm) as upper and lower facesheets with Commercial polyurethane (PU) foam (ρ = 45 Kg/m3) in core with different thicknesses (10,20&30 mm). Hybrid sandwich composites contained Aluminum/LDPE composite sheets (Al-c) or fiberglass/polyester (F.G) composite sheets (3 mm) as upper facesheet and galvanized steel sheets (0.5 mm) as lower facesheet with PU foam in core with different thicknesses. These modifications lead to enhancing the mechanical and physical properties of metallic and hybrid polyurethane sandwich composites with limited increase of sandwich composite weight.
There are three important parameters should to be investigated in this research. The effect of changing in polyurethane foam core thickness, facesheet thickness and upper facesheet material was studied on the mechanical and physical properties of metallic and hybrid polyurethane sandwich composites. The mechanical properties of metallic and hybrid polyurethane sandwich composites were studied through performing the Compression & 3-point bending tests on different sandwich composites. Specific bending flexural strength was calculated for different sandwich composites. Also, sound and thermal insulation test performed to characterize its physical properties.
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