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Expandable Epoxies A Versatile Material Pradip K. Dubey Aditya Birla Chemicals (Thailand ) Ltd – Epoxy Division (Formerly Thai Epoxy). Introduction For over 60 years foam cores have been utilized for sandwich construction.
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Expandable Epoxies A Versatile MaterialPradip K. DubeyAditya Birla Chemicals (Thailand ) Ltd – Epoxy Division(Formerly Thai Epoxy) TRFA Annual Meeting- Montreal, Canada
Introduction For over 60 years foam cores have been utilized for sandwich construction. PVC, PS, SAN, PUR, PIR, PMI, and PEI foams have been developed over the years All types of the foams are used in sandwich structure for Light weight High Stiffness and High strength TRFA Annual Meeting- Montreal, Canada
Sandwich Principle Sandwich structure provides high stiffness in bending (flexural rigidity) Foam core of sandwich do not allow increase in weight significantly. D = EI = ‘Ef’ bt3 + ‘Ef’btd2 + ‘Ec’bc3 6 2 12 Where: Ef = Elastic modulus of the skin Ec = Elastic modulus of the core b = Width of the beam d = Distance between skins t = Thickness of skin c = Core thickness TRFA Annual Meeting- Montreal, Canada
Sandwich principle If skins are relatively thin compared to core ( d/t >6) and core material is considerably weaker than the skins (‘Ef’/ ‘Ec’ . td2/c3 >17) the equation can be reduced to D = EI = ‘Ef’btd2 2 From the equation, it is distance between skins which contribute for flexural rigidity not the strength of the core material. TRFA Annual Meeting- Montreal, Canada
Sandwich Vs Single skin fiber glass structure Single skin -tSandwich-2tsandwich-4t Weight: 1 Weight: 1.06 Weight: 1.09 Strength: 1 Strength: 3.5 Strength: 9.25 Stiffness: 1 Stiffness: 7 Stiffness: 37 By increasing the cross sectional geometry Stiffness increase 37 times. Flexural strength increase 9 time. Marginal change in weight. TRFA Annual Meeting- Montreal, Canada
Two component liquid system Longer shelf life Flexible working time Easy processibility Adaptable to any shape and size Close cells, uniform, and homogeneous High strength and thermal stability Excellent electrical insulation property Excellent adhesion with most of the substrates Nonhazardous Variable density ( 150-400kg/m3) Salient features of the epoxy foam TRFA Annual Meeting- Montreal, Canada
Epotec Expandable Epoxy TRFA Annual Meeting- Montreal, Canada
Epotec Expandable Epoxy (Mechanical properties) TRFA Annual Meeting- Montreal, Canada
Epotec Expandable Epoxy(Electrical properties) TRFA Annual Meeting- Montreal, Canada
Epotec Expandable Epoxy New high strength grades containing milled glass fiber TRFA Annual Meeting- Montreal, Canada
Comparative Properties TRFA Annual Meeting- Montreal, Canada
Composite (core material)-Surf boards, Boats, Tabletops, Hockey sticks, Helmets, Wind mill blades Civil and construction- Crack filling, Pedestrian bridge/Light weight bridges, FRP doors and furniture, Manufacturing of molded panels Electrical and Electronics- Sensors, Capacitors, Encapsulation of electronic circuit Tooling- Prototype, Molds, Fixtures Adhesive- Light weight structures, In combination with other core material, Fixing tiles Applications of Epoxy Foam TRFA Annual Meeting- Montreal, Canada
Cross Section of Surf Board Top Epoxy Laminate Epoxy Foam Core Epoxy Foam Intermediate Epoxy Laminate Fins from Epoxy Laminate TRFA Annual Meeting- Montreal, Canada
Cross Section of Surf Board Epoxy Foam used as Core & Adhesives TRFA Annual Meeting- Montreal, Canada
Cross Section of Helmet Epoxy Foam Between SHELL & LINER TRFA Annual Meeting- Montreal, Canada
Composite Kayak Top Epoxy Laminates Epoxy Foam Inner Epoxy Laminates TRFA Annual Meeting- Montreal, Canada
Cross Section of Boat Osmosis Coating Epoxy Foam Cove & Bead Joint Balsa Wood Strip TRFA Annual Meeting- Montreal, Canada
Light Weight Floating Dock TRFA Annual Meeting- Montreal, Canada
Hockey Stick – Field & Ice Hockey Hockey Core From Epoxy Foam TRFA Annual Meeting- Montreal, Canada
Light Weight Table Tops Top Epoxy Laminate Epoxy Foam for Light Weight TRFA Annual Meeting- Montreal, Canada
Crack Filling by Epoxy Foam Crack on concrete floor Filled Crack After curing of crack filling Chemical there is shrinkage and hair line crack on both side joints TRFA Annual Meeting- Montreal, Canada
Epotec Expandable epoxies are easy to work and do not involve hazardous/toxic chemicals Unlike thermoplastics foams they can be molded in-situ on site in complex shapes and sizes and avoid transportation as well as further machining Simplify processing steps involving additional adhesives in some of the applications Conclusion TRFA Annual Meeting- Montreal, Canada
THANK YOU For further information please contact us at www.epotec.info or www.adityabirlachemicals.com TRFA Annual Meeting- Montreal, Canada