Compuestos de fibra de hoja de piña fabricados mediante moldeo por compresión por capas

Abstract

Compression molding process was used to manufacture composites reinforced with pineapple-leaf fibers. During manufacturing, four plies of polypropylene with an average thickness of 0.76 mm were used and the fibers were equally distributed between plies to generate a stacked composite with the fibers in external layers transversally oriented to those in the inner layer. Two types of pineapple-leaf fibers were used as reinforcement: untreated fibers and fibers modified in an alkali solution (10% NaOH). Two different fiber contents were also evaluated in order to measure their effect on the mechanical properties of the composite. Ultimate tensile strength, strain at maximum load, Young's modulus, flexural strength and flexural modulus were measured. Tensile strength was increased 22% and Young's modulus increased 60%. Flexural strength and flexural modulus increased 19 % and 50% respectively, with fiber content. However, the alkali treatment did not improve those properties. Fractured surfaces of the composites were examined using electron microscopy and failure mechanisms such as fiber pullout and matrix deformation were observed.

Influence of fiber content on rheological and mechanical properties of pineapple leaf fibers‐polypropylene composites prepared by twin‐screw extrusion

“…The Young's modulus increases also linearly with increasing fiber content (Figure A). This is also in agreement with the literature data, even though the dispersion is more important for this parameter (Figure B). In addition to the reasons mentioned earlier (nature of PALF, mode of preparation of the composites), the way in which the modulus is measured (strain gauge, slope of the stress/strain curve) can also play a role.…”

“…As expected, the elongation at break decreased drastically (about two decades) with increasing fiber content (Figure A). Once again, these results are in good agreement with the literature in which values between 3% and 20% were reported for fiber contents greater than 20 wt% (Figure B).…”

“…The stress at break increases linearly with increasing fiber content (Figure A). Considering the various studies on the mechanical properties of PALF/PP composites from the literature, it can be seen in Figure B that this is a general rule: almost all the results show a proportionality between stress at break and fiber content. Our data are in agreement with the other values of the literature.…”

“…B, Elongation at break as function of fiber content. Comparison of data from the literature: (●) present work, (○), (■), (□), (▲), (♦)…”

Development of mortar for laying and coating with pineapple fibers

“…It is possible to confirm that both incorporations, natural and treated fibers, reduce the mass density in the hardened state of mortars when compared to the reference percentage (0%). This result had already been reported by other authors (Silva et al, 2014;Jaramillo et al, 2016) and is due to the lower density that the fibers have in comparison to the other materials used in the manufacture of mortars. The described fact is beneficial from the technological point of view since mortars with lower densities contribute less significantly to the weight loadings characteristic of buildings.…”