Bending Stiffness Evaluation Of Cardboard: Comparison Between Experimental And Analytically Results [rigidez Do Papelão Ondulado: Comparação Entre Resultados Experimentais E Os Obtidos Por Cálculo Analítico]

Cardboard packing for horticultural products has as main function to protect them. The design of a cardboard packing request the knowledge of the bending stiffens which is depending on the modulus of elasticity. The objective of this work was to calculate the cardboard modulus of elasticity from data obtained in laboratory using physical characterization test, with different methods, and comparing the results with the values obtained experimentally. Ten samples of each cardboard selected for this study were tested in the paper fabrication direction and in its transverse direction. The papers liner and medium resistance to the traction, used to calculate the bending stiffness, was determined in a universal machine test. To obtaining of the bending stiffens the four points test was accomplished. Expressive variations among the methods from which the modulus of elasticity is obtained were observed and that influence the bending stiffness of the structure. The stiffness values obtained experimentally were always greater than the values obtained from analytical method. This difference can be attributed to two factors, the production processes that assurance a larger rigidity than the components separately and the addition of the adhesive layer that is not taken in consideration in the analytic calculations.261190199Baum, G.A., Habeger, C.C., On-line measurement of paper mechanical properties (1980) Tappi Journal, 63 (7), pp. 63-66. , AtlantaCarlsson, L., Fellers, C., Jonsson, P., The bending stiffness of corrugated board under special consideration of asymmetrical and multi-ply construction (1985) Das Pappier, 39 (4), pp. 149-156. , DarmstadtChitarra, M.I.F., (1990) Pós-colheita de Frutos e Hortaliças: Fisiologia e Manuseio, 320p. , Lavras: ESAL/FAEPEMourad, A.L., Garcia, A.E., Bordin, M.R., Adito, E.F.G., (1999) Embalagens de Papel, Cartão e Papelão Ondulado, 282p. , Campinas: ITALPichler, E.F., (2000) Embalagem: Desenvolvimento, Especificação, Controle de Qualidade e Custos, 24p. , São Paulo: IPT/LEAPommier, J.C., Poustis, J., New approach for predicting box stacking strength (1989) Revue A.T.I.P., 43 (5), pp. 217-221. , ParisPommier, J.C., Poustis, J., Foucade, E., Morlier, P., Determination of the critical load of a corrugated box subjected to vertical compression by finite elements methods (1991) Proceedings..., pp. 437-447. , INTERNATIONAL PAPER PHYSICS CONFERENCE, 6., 1991, Kailua Kona. Kailua Kona: TAPP