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Technologies like bunch covers have been shown to improve quality of date fruits. It is one of the approaches which are believed effective to protect the most sensitive stage of date fruit from autumnal rain and carob date. An experimental procedure is set up to allow farmers to predict, analyze, and optimize cover bunch performance after its use in protection applications and to select the ideal bag. The cover quality is designed based on a mathematical model and further optimized using MINITAB. From this analysis, the impact of each individual parameter on the desired response parameters has been studied. The results proved that the best cover could be found in optimal conditions. Using the influential parameters as tear strength, tensile strength, weight, air permeability and resistance to water penetration, the results indicate that the cover bunch remains influenced after harvesting period by the resistance to water penetration properties and tear strength as well. [ABSTRACT FROM AUTHOR]

According to literature survey, many works have dealt with studying the effect of some bags on biological, chemical and physical quality of date fruit. In this study, RSM (response surface methodology) modeling and desirability function methods were applied and compared to predict the overall quality of cover date bunch samples. Five nonwoven bagging product are selected to be examined that are used for the first time on date palm sector. The results proved that a high quality of bagging product could be obtained in optimal conditions. Using the influential parameters and optimized conditions as fabric weight, thickness, air permeability, resistance to water penetration, tear strength and tensile strength, the results indicate that the cover date bunch remains influenced especially by the air permeability properties and tensile strength as well. Desirability function has been proven to be effective to achieve ideal design performance. The results show that the highest desirability reached is 0.6.However, the efficient approaches to identify the relevant parameters and the relation between different quality features and parameters have not been completely studied. To overcome the gap, a combined method including desirability function and response surface methodology (RSM) was proposed. Referring to previous works, desirability function allows a high level of flexibility over classical mathematical methods in evaluating and defining global quality. According to the analytical results obtained, the desirability function method gives a more accurate prediction than the RSM one. [ABSTRACT FROM AUTHOR]

This paper presents the results of the first kenaf spinning attempt in Tunisia. Indeed, kenaf fibers are rigid and lack of cohesion that makes their spinning difficult and a challenge. So, this paper describes the possibility of spinning different blends of kenaf/cotton fibers using open end spinning machine. Five different blends of kenaf/cotton (M1:10/90, M2:20/80, M3:30/70, M4:40/60, and M5:50/50) were considered. The higher kenaf content in the blend make spinning process difficult and even impossible. The produced yarns were characterized to evaluate their mechanical properties and compare it to similar yarn performances. These blends gave different yarn counts varying from 41.86 to 69.16 tex, tenacity of 8.80 cN/tex to 10.07 cN/tex, while elongation at break of 7% to 8.93%. The results proves that kenaf/cotton 40/60 blend ratio presents the better mechanical properties and regularity with 8.80 cN/tex for tenacity and 7.68% for elongation with good regularity index Ireg = 1.25. [ABSTRACT FROM AUTHOR]

Recognizing the importance of using plant fibers in polymeric composites and the no availability of data on fine structure, physico-chemical, morphological and others properties of Typha Angustata stem fibers, a study was undertaken with the objective of determining some of these properties. In this work, untreated and treated Typha stem fibers by NaOH treatment have been extracted and characterized to evaluate and compare their surface condition as well as their chemical composition, their fine structure and their mechanical properties. Typha stem treated fibers (TSTFs) have presented best results with an alpha-cellulose content of 51.3%, a density of 1460 kg/m3, an average tensile strength equal to 9.42cN/tex and a diameter of 208.12 µm. Also, Crystallinity Index (CI) of TSTFs was 57.4%. Unsaturated polyester matrix was reinforced with TSTFs and mechanical properties were undergone. Results show that TSTFs could be used for sustainable fiber-reinforced polymer composites with an enhancement in flexural and tensile tests for 12.6% TSTFs ratio. [ABSTRACT FROM AUTHOR]

Water injury and fungus infection are the main causes of large economic deterioration and losses in the quality of date fruits during harvesting period. The nonwoven bagging product was used for the first time on date palm and has been shown to efficiently protect date fruit from heavy rain and sunburn that reduces the rate of transpiration and increases fungus spoilage. The aim of this study is to evaluate the potential applicability of COMSOL code in simulating the heat transfer behavior through nonwoven date cover. The study also intended to use finite element method and adaptive mesh refinement technique to increase the accuracy of the solution and create model for efficient simulation of heat exchange in nonwoven bag. The proposed model was validated by the uniformity between simulating and experimental results. A detailed numerical study was conducted to find the influence of air permeability on heat transfer through nonwoven textiles. Results demonstrated that the reduction of nonwoven permeability is beneficial to minimize the heat taken away by forced convection by decreasing the inner air transportation. [ABSTRACT FROM AUTHOR]

Effect of fiber treatment on the strain We can conclude from figures presented previously that all composite tensile properties are improved when increasing the fiber weight ratio and also after the chemical treatment of the fibers used for. Fiber weight ratio of composites HT