Influence of reinforcement phase form on bending strength of polymer composites
Marek Pijanowski, Bartosz Głowacki, Janusz Grabian
Quarterly No. 1, 2011 pages 80-83
DOI:
keywords: polymer composites, flexular strength
abstract Composites belong those materials that are systematically developed due to the rapid technological advancements observed in recent years. These materials are successfully used in various fields just because it is possible to obtain the desired properties through adequate selection of the reinforcement and matrix, the components of a new material. It is important, however, that the distribution of the reinforcement phase be as uniform as possible, particularly in laminates, where reinforcement layers undergo saturation. If this requirement is satisfied, the composite has good quality, especially when high material strength is the desired property. In this study, two kinds of laminate composites that differ in their reinforcement type are compared. In both cases, the reinforcement was composed of glass fiber (a mat, made of roving, cut into short pieces, chaotically placed in a plane; , and a woven fabric, made of long roving, produced by interweaving bundles of fiber glass at right angle in a the plane). The matrix was epoxy resin (Epidian 5 with Z1 hardener). A series of samples was prepared, that differed in the number of reinforcement layers (3, 6, 9, 12). They were tested for bending according to the PN-EN ISO 178 standard: ‘Synthetic materials: determination of properties in bending tests’, using a testing machine H10K-T. The test results lead to a conclusion that the best bending properties are obtained for laminates with reinforcement arranged in the form of a fabric, which is due to the advantageous distribution of stresses on the long fibres of the reinforcement. Bending strength also depends on the number of reinforcement layers. In this respect, both types of material (mat, fabric) with nine layers yield the best results. The calculated values will be utilized in further research for the creation of a mathematical model describing the strength of tested laminates depending on the number of layers and type of reinforcement phase.