Effects of Moisture Content on the Mechanical Properties of Polyphenylene Sulfide Composite Materials

Author(s):  
SV Hoa ◽  
S Lin ◽  
JR Chen
2017 ◽  
Vol 380 ◽  
pp. 66-71 ◽  
Author(s):  
D. Gomes dos Santos ◽  
A.G. Barbosa de Lima ◽  
P. de Sousa Costa

Vegetable fibers have been used in most several applications, as raw material, for manufacturing of different products or directly as reinforcement in composite materials. Green fibers are wet, what requires its drying before their use.In this sense, the aim of this work is to study drying of the sisal fibers in oven. Drying experiments were carried out at different drying condition. It was evaluated the curves of moisture content, drying and heating rates and temperature, as well as the influence of the drying temperature on the mechanical properties of the fibers. It was found that the drying temperature (60 - 105°C) had no significant influence on the tensile mechanical properties, elongation at rupture and modulus of elasticity of the sisal fibers.


Author(s):  
Д.В. ЕВТЕХОВ ◽  
Р.В. БЕЗНОСЮК ◽  
С.Т. КОДИРОВ ◽  
Г.К. РЕМБАЛОВИЧ ◽  
Н.С. ЖБАНОВ

Проблема и цель. В процессе уборки картофеля меняются почвенно-климатические условия, урожайность, свойства убираемых клубней и поэтому уборочный комплекс должен гибко реагировать на эти изменения. Это предполагает не только своевременную настройку рабочих органов, но и более широкие возможности современных картофелеуборочных машин. Цель – совершенствование картофелеуборочных машин на основе применения полимерных и композиционных материалов. Методология. Появление в бункере комбайна клубней с повреждениями, ушибами (потемнение мякоти) свидетельствует о значительных динамических нагрузках рабочих органов. Предлагаемый сепарирующий элеватор имеет гибкие композиционные прутки, которые взаимодействуют с обрезиненными роликами-интенсификаторами и при движении образуют волнообразную, постоянно меняющуюся поверхность. При поступлении картофельного вороха гибкие композиционные прутки прогибаются, причем чем больше масса поступающего картофельного вороха, тем больше величина прогиба прутков. При изменении почвенно-климатических условий значительная нагрузка приходится на органы выносной сепарации, поэтому увеличение производительности и снижение повреждений клубней является важной задачей. Для повышения эффективности работы продольной прямоточной пальчиковой горки был предложен многокулачковый встряхиватель с регулируемой частотой и амплитудой воздействия. Благодаря колебательным воздействиям полотна пальчиковой горки картофель приобретает дополнительную подвижность, что позволяет более полно использовать различия физико-механических свойств клубней и примесей. Результаты. Применение сепарирующего элеватора с композиционными прутками увеличило сепарирующую способность картофелекопателя на суглинке нормальной влажности (22 %) и снизило повреждения клубней на 2,6 %. Сравнительные показатели качества работы комбайна Grimme DR-1500, оборудованного модернизированной горкой с многокулачковым всряхивателем и серийного комбайна Grimme DR-1500 соответственно составили: полнота уборки – 97,3 % и 95,8 %; полнота выделения примесей – 94,1% и 86,8 %; процент повреждений клубней –2,47 % и 3,15 %. Заключение. Увеличение интенсивности сепарации на рабочих органах из композиционных и полимерных материалов позволяет увеличить производительность картофелеуборочных машин. Problem and purpose. In the process of harvesting potatoes, the soil and climatic conditions change, the yield properties of the harvested tubers, and therefore the harvesting complex must respond fexibly to these changes. This presupposes not only the timely adjustment of the working bodies, but also the wider possibilities of modern potato harvesters. The goal is to improve potato harvesters based on the use of polymer and composite materials. Methodology. The appearance of tubers with injuries in the bunker of the combine with bruises (darkening of the pulp) indicates signifcant dynamic loads of the working organs. The proposed separating elevator has fexible composite rods, which interact with rubberized intensifer rollers and, when moving, form a wavy, constantly changing surface. When the potato heap arrives, the fexible composite rods bend, and the greater the mass of the heap, the greater the defection. With a change in soil and climatic conditions, a signifcant load falls on the external separation organs, therefore, increasing productivity and reducing damage to tubers is an important task. To increase the efciency of the longitudinal direct-fow hedgehog slide, a multi-cam shaker with an adjustable frequency and amplitude of action was proposed. Owing to the vibrational efects of the hedgehog slider, the potato acquires additional mobility, which allows more full use of the diferences in the physical and mechanical properties of tubers and impurities. Results. The use of a separating elevator with composite rods increased the separating capacity of a potato digger on loam of normal moisture content (22%) and reduced damage to tubers by 2.6%. Comparative performance indicators of the Grimme DR-1500 combine equipped with a modernized slide with a multi-cam shaker and the Grimme DR-1500 serial combine, respectively, were: completeness of cleaning –97.3% and 95.8%; completeness of separation of impurities – 94.1% and 86.8%; percentage of damage to tubers –2.47% and 3.15%. Conclusion. An increase in the intensity of separation on working bodies made of composite and polymer materials allows increasing the productivity of potato harvesters.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Asim Shahzad

This paper presents the results of the experiments undertaken to evaluate various physical and mechanical properties of hemp fibres. The study of these properties is vital for comparison with similar properties of synthetic fibres and for assessing hemp fibres’ suitability for use as reinforcement in composite materials. The properties of hemp fibres were found to be good enough to be used as reinforcement in composite materials. However, the issues of relatively high moisture content of fibres, variability in fibre properties, and relatively poor fibre/matrix interfacial strength were identified as factors that can reduce the efficiency with which these fibres can be utilised.


2020 ◽  
Vol 26 (3) ◽  
pp. 308-316
Author(s):  
Svetlana RISTESKA ◽  
Anka T. PETKOSKA ◽  
Samoil SAMAK ◽  
Marian DRIENOVSKY

In situ consolidation of thermoplastic composites by Automated Tape Placement (ATP) is challenging. High quality ATP grade pre-preg material and tape head equipped with an efficient heat sources like lasers offer an opportunity towards high deposition rates and improved mechanical properties of composite materials. In this study uni-directional carbon fiber/ polyphenylene sulfide (UD tape prepreg CF/PPS), carbon fiber/polyetheretherketone (UD tape prepreg CF/PEEK) as well as blend of carbon fiber/polyetheretherketone/polyphenylene sulfide (UD tapes prepregs CF/PEEK/PPS) laminates are compared in terms of their properties after beeing processed by ATP technology. CF/PPS, CF/PEEK and blend CF/PPS/PEEK laminate specimens were processed using in-situ laser-assisted ATP (LATP) process. LATP processing parameters used in this study were chosen based on a preliminary trials; the results provide a basis for refinement of these parameters and prepreg material with an optimal and balanced set of final mechanical properties. This study showed an attempt how to manage the processing parameters for LATP process and to obtain composite materials with tailored properties. The process for production of thermoplastic plates with LATP head in general is a process that is governed by many parameters such as: laser power, angle of incidence, roller pressure and temperature, placement speed, tool temperature, then types of the roller material and the tool material. These parameters are not subject of discussing in this paper; they are kept constant, and the goal of the paper is to manage the crystallinity level within the composite thermoplastic material during annealing step at different temperatures after LATP process. Also, the void content during the production process could be controlled. More particularly, the authors showed that composites based on PPS matrix manufactured with LATP process possess higher flexural strength, with less void content compared to samples based on PEEK matrix. These samples showed also higher crystallinity after annealing step.


2012 ◽  
Vol 504-506 ◽  
pp. 243-248 ◽  
Author(s):  
Peng Wang ◽  
Nahiene Hamila ◽  
Philippe Boisse

The Continuous Fibre Reinforcements and Thermoplastic resin (CFRTP) are widely employed in the prepreg processes. Currently, the most used thermoplastic resins in aeronautics are PPS (polyphenylene sulfide) and PEEK (Polyetheretherketone). They present many advantages on their mechanical properties. However, these mechanical properties depend strongly upon the thermoforming conditions, especially the intraply shearing. In order to improve and complete the understanding about the in-plane shear behavior of thermoplastic composite materials in their forming processes, the thermo-mechanical analysis of PPS/carbon and PEEK/carbon commingled fabrics at different forming temperatures are performed by using the bias-extension tests. The experimental data leads to significant difference on the in-plane shear behavior under different temperature, as well as the wrinkles can be noted in certain thermoforming conditions. Therefore, in order to predict the feasible forming conditions and optimize the important forming parameters of the thermoplastic composites, the in-plan shear behaviors in function of temperature will be integrated into our numerical model to carry out the numerical simulations of thermoforming processes.


A study review of aging polymer composite materials (PCM) under different heat-moisture conditions or water exposure with the sequential or parallel influence of static or cyclic loads in laboratory conditions is presented. The influence of tension and bending loads is compared. Conditions of the different load influence on parameters of carbon-reinforced plastics and glass-reinforced plastics are discussed. Equipment and units for climatic tests of PCM under loading are described. Simulation examples of indices of mechanical properties of PCM under the influence of environment and loads are shown.


A study review of aging polymer composite materials (PCM) under different heat-moisture conditions or water exposure with the sequential or parallel influence of static or cyclic loads in laboratory conditions is presented. The influence of tension and bending loads is compared. Conditions of the different load influence on parameters of carbon-reinforced plastics and glass-reinforced plastics are discussed. Equipment and units for climatic tests of PCM under loading are described. Simulation examples of indices of mechanical properties of PCM under the influence of environment and loads are shown.


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