O. R. R. F. Silva

Caracterização química e estrutural de fibra de sisal da variedade Agave sisalana

In recent years, the interest in the use of natural fibers in polymeric composite materials has increased significantly. In this work were investigated the structural, thermal, chemical, and physical properties of Brazilian sisal fiber from Agave sisalana variety. Our aim was to evaluate the quality and the performance of this fiber for industrial applications. Mechanical properties, chemical composition, X ray diffraction, and scanning electron microscopy (SEM) have been investigated with fibers along their length. The Brazilian sisal fibers studied have exhibited mechanical and thermal properties within the range reported in the literature and were suitable for use in polymeric composites.

Bole rot of sisal caused by Aspergillus niger in Brazil

A ocorrencia da podridao do tronco do sisal, causada por Aspergillus niger, e relatada pela primeira vez no Brasil. A doenca foi observada em campos de producao nos Estados da Bahia, Paraiba e Rio Grande do Norte

Qualidade da semente e fibra de algodão na caracterização do descaroçador de 25 serras 1

A B S T R A C T The cotton is one of the most important crop in the fiber group due to its volume and valued production. This study was conducted with the aim to characterize a ginner regarding physical and physiological quality of seeds and some technological qualities of the cotton fiber. The ginner was made with the following components: cleaner, cylinder saws, cylinder brushes, condenser, and a three-phase electric motor of 3 CV to turn on the equipment. The experimental design was a completely randomized factorial (2 x 2 x 2 x 4), with two cotton cultivars (BRS 187 and BRS Safira 8H), two types of saws (11¾” and 12”), two cleaning process (with and without cleaner) and four rotations (500, 550, 600 and 650 rpm) and four replications. During the processing of seeds, types of saws and cleaning processes did not affect the physical and physiological quality of seeds. Meanwhile, in the technological characteristics of the cotton fiber, the ginner showed efficient performance with the rotation of 550 rpm, using the 12” saws and cleaning device turned activated (cleaner). Palavras-chave: beneficiamento qualidade de sementes qualidade de fibras

Desenvolvimento e avaliação de descaroçador para o beneficiamento do algodão

In this study a ginner of 20 saws was developed for processing cotton seeds. The constituent parts of the ginner of 20 saws essentially consist of the following devices: static frame (chassis), consisting of two iron plates of 6.35 mm thickness, for the support of other components of the machine; a box of cotton accumulator; chamber of a mass of cotton ginning; device for regulating the amount of linter; a cylinder composed of 20 saws, another of brushes; a capacitor; gear for shifting and activating the cylinder, ginner discs; a three-phase 5 HP electric motor, 320-220 V to drive the devices for processing, by means of pulleys and belts, and automatic switch. The evaluation of the 20 delinter saws was done in assessment with 50 and 90 saws machines widely used by the cotton benefiting factories in Northeast Brazil. The ginner developed responds satisfactorily to treatment of cotton seeds with performance similar to the machines of 50 and 90 saws for all technological fiber characteristics analyzed in HVI. The efficiency of the work of ginner was at 344 rpm, with the device to adjust the amount of linter in position A and the sample of 600 g.

Ginning impact on the number of neps and amount of cotton fiber contaminants.

Objetivou-se, neste trabalho, estudar o efeito do beneficiamento sobre o conteudo de impurezas, po e o numero de neps na pluma, em 12 algodoeiras do Estado de Mato Grosso. O experimento consistiu de uma combinacao fatorial de cinco etapas de beneficiamento do algodao em 12 algodoeiras em delineamento inteiramente casualizado com quatro repeticoes. Amostras de algodao foram coletadas nas seguintes etapas: a) no desmanche do fardao; b) antes do descarocamento; c) logo apos o descarocamento; d) na bica, sem o uso do limpador tipo serrilha; e) na bica, apos a limpeza da pluma, utilizando-se o limpador tipo serrilha. Em todas as etapas se retiraram quatro amostras padrao de pluma com massa de 350 g a fim de serem analisadas mediante o instrumento AFIS (Advanced Fiber Information System) para determinacao do conteudo de impurezas e poeira e o numero de neps da fibra. Os resultados indicam que os processos de prelimpeza do algodao em caroco e limpeza da pluma reduzem o conteudo de impurezas e da poeira do algodao enquanto, juntamente com o descarocamento, esses processos aumentaram o numero de neps da fibra do algodao. A utilizacao do limpador de pluma tipo serrilha com manta continua aumenta a eficiencia de limpeza da pluma, porem ocasiona incrementos significativos no numero de neps.