Resumo

PESTANA, Miguel; LOUZADA, José  e  SARDINHA, Raúl. Classification of Cork Oaks for the Production of Cork, Appealing to an Objective Criterion. Part III - The Stoppers . Silva Lus. [online]. 2006, vol.14, n.1, pp.33-49. ISSN 0870-6352.

This paper reports the results of the continuation of the research line on the classification of cork quality and follows the articles entitled ""Classification of the corks for the cork production, using a objective criterion. Part I-The strips and Part II-The Samples" already published. It intends to be a contribution for a better knowledge of the quantitative qualification of the cork, consolidating the proposal of a criterion classification based on objective parameters capable to be reproducible, independent of the operator and so expedite as possible. Evaluation parameters used such as the specific gravity, rupture strength and the corresponding angle, were collected on cork samples prepared for that purpose. A comparison of the qualitative classification developed by CARVALHO (1993) (punctuation criterion), applied to the cork samples of 9 samples trees, with those generated by the criterion resulting from the data of the physical characteristics from stoppers, obtained from cork sample from the same sampled trees, was made. The results of this work showed that: ·  The objective classification based on physical and mechanical parameters, assures the reproducibility of the results, which does not happen with the punctuation criterion. ·  The stoppers allowed the verification of the relationship between the specific gravity and the rupture angle, i.m., actuating in an inverse way and the rupture strength is independent to this relationship. ·  The bad stoppers showed high values of specific gravity and low values of the rupture angle whilst we verified the opposite on the good ones. ·  The cork anisotropy is more evident when we moved to the smallest samples, which in our case, are the stoppers.

Palavras-chave : quality; mechanical tests; physical tests; multivariate analyses.

        · resumo em Português | Francês     · texto em Português     · Português ( pdf )