Study on plant fiber/plastic composites as the substrate of floorboard

Three kinds of composites （fiber/Polypropylene, fiber/Polyethelene, and fiber/Polystyrene） were made by using hot pressing process for substrate of floorboard and the properties of each kind of composites were tested. MORs of PP/wood fiber, PS/fiber, and PE/fiber composites with coupling agent added were raised by 18.4%, 37.1%, and 42%. respectively, compared to those without coupling agent. Among the three kinds of fiber/plastic composites, fiber/PP composite has best mechanical properties, and it can meet quality standard of eligible grade product and come up to the excellent grade products of China when the coupling agent is added. The performance of composite made of PE/fiber or PS/fiber can exceed qualified product grade only with coupling agent added.

Impact Responses of the Carbon Fiber Fabric Reinforced Composites

To study the response characteristics of the carbon fiber fabric reinforced composites under impact loading, one dimensional strain impact test, multi gauge technique and Lagrange analysis method are used. The decaying rule of the stress σ , strain ε , strain rate ε · and density ρ with time and space is obtained. By the theory of dynamics, the impact response characteristics of the material is analyzed and discussed.

Prediction of Fiber Composition and Silicificationfor Rice Straw with Near Infrared ReflectanceSpectroscopy (NIRS) Technique

The silicification of rice straw is a factor that affects the grain production and straw nutritive quality. The procedure of chemical analysis for silicon in straw is, however, time and labor consuming, and slightly poor in accuracy. The study has attempted to apply near infrared reflectance spectroscopy (NIRS) technique as an advanced alternative to predict the fiber composition and silicification in rice straw. Ninety-two samples from different seasons and varieties were collected over the Fujian Province. Their chemical analyses were carried on the aspects of hemicellulose, cellulose, lignin, extractable and non-extractable silicon, and the results were used as a database for NIRS analyses. The prediction model was developed through modified partial least square regression (MPLS) for a calibration program. The factors that may affect the calibration, cross-validation and the prediction for the application of NIRS on rice straw were also discussed.

Carbon Fiber Breakage Mechanism in Aluminum(Al)/Carbon Fibers(CFs) Composite Sheet during Accumulative Roll Bonding(ARB) Process

We put forward a method of fabricating Aluminum(Al)/carbon fibers(CFs) composite sheets by the accumulative roll bonding(ARB) method. The finished Al/CFs composite sheet has CFs and pure Al sheets as sandwich and surface layers. After cross-section observation of the Al/CFs composite sheet, we found that the CFs discretely distributed within the sandwich layer. Besides, the tensile test showed that the contribution of the sandwich CFs layer to tensile strength was less than 11% compared with annealed pure Al sheet. With ex-situ observation of the CFs breakage evolution with-16%,-32%, and-45% rolling reduction during the ARB process, the plastic instability of the Al layer was found to bring shear damages to the CFs. At last, the bridging strengthening mechanism introduced by CFs was sacrificed. We provide new insight into and instruction on Al/CFs composite sheet preparation method and processing parameters.

The properties of flax fiber reinforced wood flour/high density polyethylene composites

Flax fiber(FF) was used to reinforce wood flour/high density polyethylene composites(WF/PE).WF/PE particles were uniformly mixed with FF via high-speed mixing and then extruded with a single screw extruder to prepare FF reinforced WF/PE composites(FF/WF/PE).Mechanical testing,dynamic mechanical analysis,scanning electron microscopy(SEM),creep measurement and Torque rheology were used to characterize the resulting composites.The results indicate that the mechanical performance of the composites could be remarkably improved by adding a limited amount of FF.The flexural strength and modulus increased by 14.6 and 51.4%,respectively(FF content of 9 wt%),while the unnotched impact strength could be increased by 26.5%(FF content of12 wt%).The creep resistance and toughness of thecomposite was markedly improved without changing the plastic content of the composite material.

The Accelerated Thermo-Oxidative Aging Characteristics of Wood Fiber/Polycaprolactone Composite:Effect of Temperature,Humidity and Time

This study investigated the characteristics of wood fiber/polycaprolactone composite after an artificial accelerated thermo-oxidative aging treatment.The effect of time,temperature and humidity during the treatment on their mechanical,chemical and morphology properties were evaluated.The composite was prepared from melted wood fibers and modified polycaprolactone by a molding process.A temperature and humidity controllable test chamber was used for the thermo-oxidative aging of the composite.The thermo-oxidative aging caused surface of the composite to be much more rougher and even a few cracks and holes appeared on it.According to the spectra of Fourier Transform Infrared(FTIR)and Gel Permeation Chromatography(GPC),C=O in the molecular chain of polycaprolactone was hydrolyzed and C–O was broken after the aging treatment,which resulted in a reduction in average molecular weight of the composite.Moreover,results showed that the mechanical strength decreased a lot with the increase in time,temperature and humidity,and the effect of temperature and humidity was more significant compared with that of time.Controlling the temperature and humidity during thermo-oxidative aging treatment could accelerate the aging of composite,which provided a quick and effective method for evaluating the aging resistance of the composite.

Reinforcement of Plastic Waste with Treated Natural Fibers

Plastic wastes are a major environmental concern that needs to be dealt with to minimize the amount of municipal solid waste and depletion of natural resources thus enhancing the sustainability concept for future generations. The objective of this study is to enhance the properties of plastic products using plastic wastes reinforced with treated natural fibers such as rice straw as well as carbonized rice straw, using a simple and efficient technology.

DELAMINATION FORMATION AND DELAMINATION PROPAGATION OF COMPOSITE LAMINATES UNDER COMPRESSIVE FATIGUE LOADING

Fatigue tests of the smooth composite laminates and the notched composite laminates under compressive cyclic loading have been carried out. The damage mechanism is discussed and analyzed. Damage evolution is monitored using stiffness decay. From these tests, it is found that the initial delamination occurs at the free boundary of smooth specimens, or the notch boundary of notched specimens, subjected to the compression-compression cyclic load. A point of view in relation to two-phases of compression fatigue delamination of composites is proposed, namely, compression-compression delamination consists of the delamination formation phase and the delamination propagation, and there is a 'damage transition point' to separate this two-phases. Furthermore, an empirical modulus degradation formula and its parameters fitting method are presented. According to the test data handling results, it is shown that this formula is univocal and can fit the test data conveniently. In addition, two kinds of new anti-buckling devices are designed for these tests. At last, the E-N curves, the D-N curves and the S-N curve of the smooth carbon fiber reinforced composite laminates of T300/648C are determined to predict the fatigue life of the notched composite laminate. And the E-N curve of the notched specimens at the given load ratio R = 10 and minimum load Pmin = -0.45 kN is also measured to verify the estimated result of fatigue life.

Experimental Investigation of Natural Fiber Reinforced Polymers

The potential usage of virgin Low density polyethelyne (LDPE) reinforced with different concentrations (2%, 5% and 6% by weight) of treated rice straw with different lengths (2 mm, 4 mm and 6 mm) is investigated to produce high value products that have technical and environmental demand. The two treatment methods used for rice straw are alkali and acidic treatments of rice straw. The removal of impurities and waxy substances from fiber surface avoid creation of rougher topography after treatment and improves the quality of fiber, also content of hemi cellulose and lignin decrease so increase effectiveness of fiber due to dispersing of fiber in matrix. The reinforcing material is embedded in the matrix material to enhance tensile and flexural behaviors of the synthesized composite. The result of investigating these two mechanical properties, using statistical analysis & design of experiments, showed an enhancement in the mechaniccal properties of the virgin polymer composite compared to the virgin polymer. The flexural stress of the composite increased three times the virgin flexural stress, while the tensile stress increased eight times the original tensile stress.

Mechanical properties of straw basalt fiber reinforced concrete composites

One of the biggest problems responsible of the nonrenewable resources depletion and environmental issues is the construction industries,which generates large amounts of mineral waste and harmful emitted gases.Therefore,these problems generated the necessity to search for alternative natural building materials based on renewable resources.To study the mechanical characteristics and microstructural behavior of the concrete reinforced by raw wheat straw basalt fiber composite(RWSBFc),and treated rice straw basalt fiber composite(TRSBFc),a number of experimental tests were carried out with different composites ratios.Concrete compressive strength,splitting tensile strength,and flexural strength tests were considered as main parameters.The results showed that the RWSBFC has a positive effect on concrete flexural strength by increasing of 12.58%,compared with control samples.Also,it showed good enhancement in concrete flexibility and ductility.In contrast,both RWSBFc and TRSBFc showed uneven deterioration in concrete compressive strength and splitting tensile strength.To avoid the deterioration in compressive strengths of the various composites types,some improvement methods such as processors for the used straw,and adding some additives were recommended.

Detection of stacking orientation error of CFRP composite laminates using ultrasound waves

A jig was developed for generating a shear wave. A pyramid with an isosceles triangle with two 45o was made of aluminum to generate shear waves using two longitudinal transducers based on ultrasonic-polarized mechanism. Also, the signal splitter was connected to the pulser jack on the pulser/receiver and to the longitudinal transducers. Therefore, an experimental way was performed in order to make shear wave on the bottom of aluminum alloyed pyramid. Also, a jig was manufactured and developed for generating a shear wave based on the computer numerical simulation. It is found that the experimentally shear wave variation of newly-designed jig is consistent with computer numerical simulation results and shear wave ultrasonic application can be very useful to detect the defects in CFRP composites.

竹质纤维形态对聚乳酸基竹塑复合材料性能的影响

为高值化利用竹材加工剩余物资源,以聚乳酸(PLA)为基体,竹粉纤维(BF)、竹屑纤维(BS)、竹原纤维(BN)与竹浆纤维(BP)为填料,采用密炼-注塑工艺制备了四种竹塑复合材料,研究了竹质纤维种类对其结构与性能的影响。研究结果显示,BP与BN纤维长径比更大,BS中颗粒形态较多,BF与BS质地较刚硬。BF、BN与PLA共混熔体的混炼扭矩更大,PLA/BP复合材料吸水率最大。BF,BS,BN与PLA的界面相容性较好,其添加改善了复合材料的力学性能,而BP添加降低了复合材料的力学性能。与PLA相比,在纤维质量分数为30%时,PLA/BF,PLA/BS与PLA/BN复合材料拉伸强度分别提高了17.85%,13.6%,11.89%,冲击强度分别提高24.33%,18.70%,35.57%,弯曲强度分别提高19.45%,21.45%,4.99%。PLA/BF复合材料的综合力学性能最优,其次为PLA/BS复合材料,PLA/BP复合材料最差。研究可为竹塑复合材料的开发与应用提供有益参考。

纤维复合材料在调水工程长输管道中的应用

调水工程长距离输水管道的材料选择,对工程成本和输水线路的安全有着重要影响。纤维复合材料具有轻质高强、内壁光滑、耐腐蚀性好等特点,正逐步应用在输水管道中。文章分析了影响长距离输水管道材料选择的主要因素,介绍了钢管、球墨铸铁管、混凝土管等传统输水管道的材料特性,阐述了纤维复合材料在输水管道中的应用,重点分析了玻璃钢夹砂管的发展和特点,最后对纤维复合材料输水管道在产品升级、施工技术、安全防护和质量管理四个方面的发展进行了展望。

纤维预处理对木塑复合材料力学性能影响的研究进展

本文综述了近年来国内外关于纤维增强木塑复合材料的研究进展,重点探讨了物理、化学和生物预处理方法对复合材料力学性能的影响。旨在通过总结不同预处理方法的特点及其对木塑复合材料性能的影响,为优化复合材料生产工艺提供理论依据和技术指导。

聚合物基复合材料用预处理秸秆纤维的研究进展

近年来,秸秆纤维在生物基复合材料的研发中备受关注。秸秆纤维具有丰富的物产资源和广阔的应用前景,但纤维表面含有大量羟基,与非极性聚合物基体的复合界面相容性较弱,导致其复合材料整体性能不佳。该文详细综述了秸秆纤维预处理的方法,包括物理法、化学法、生物法、物理化学联合法和其他预处理法,讨论了秸秆预处理方法对聚合物基复合材料性能的影响,比较了不同秸秆预处理技术的优缺点及应用前景,在此基础上对秸秆纤维预处理研究进行了展望,以期为新型复合材料的设计和开发提供参考。

刀具类型及工艺方法对纤维增强复合材料制孔加工质量影响的研究进展

概括总结了刀具类型及工艺方法对纤维增强复合材料(FRC)制孔加工质量影响的最新研究进展。首先介绍了FRC的分类、特性及其在航空航天领域中的应用,以及传统麻花钻制孔刀具及工艺存在的加工缺陷及问题;其次,概述了FRC制孔的分层缺陷形成及评价;再次,从制孔刀具类型及工艺方法两方面,分别概述了FRC制孔加工质量的研究进展,并总结了改善制孔加工质量的新刀具、新工艺和新方法;最后,分析总结了刀具类型及工艺方法对FRC制孔加工质量效果的影响,同时对未来发展趋势和未来工作研究可能方向进行了展望。

熔融沉积法3D打印天然植物纤维/可降解塑料复合材料的进展

近年来,3D打印技术在国内外得到了广泛关注。熔融沉积成型(FDM)为目前3D打印技术中最常用的一种工艺方法,可降解塑料为FDM使用较多的原材料。但是,单一的可降解塑料材料的成本较高,存在性能缺陷,限制了其在3D打印技术领域中的进一步发展。利用天然植物纤维与可降解塑料进行复合,用于FDM 3D打印,不仅能降低材料的成本,还可以改善材料的部分性能,因此,该类复合材料越来越多地被应用于FDM 3D打印领域,可以替代单纯的可降解塑料。对该领域的最新研究进展进行了综述,重点阐述了各类植物纤维与聚乳酸等可降解塑料复合后,在FDM 3D打印工艺中的研究及应用。

竹塑复合材料性能改良研究进展

竹塑复合材料是将竹纤维和聚合物基体合理复合制备的一种满足功能需求的生物质复合材料,具有广阔的应用前景。但竹纤维与聚合物之间的界面相容性差,导致其在应用中出现性能缺陷,解决该问题的关键在于改善二者之间的界面相容性。本文总结了四类可行的改善界面结合的措施以提高复合材料性能,包括竹粉改性处理、聚合物改性处理、中间相桥接和填充引入四方面,并阐述了不同的改性方法对复合材料性能的影响。

复合混凝土材料及不同蜂窝夹芯结构的力学性能综述

为全面开展复合混凝土材料制备蜂窝夹芯板的研究,综述了国内外关于稻草秸秆纤维与纳米二氧化硅复合混凝土材料及蜂窝夹芯结构的研究,分析了各种检测方法,概述了稻草秸秆纤维与纳米二氧化硅复合混凝土材料及不同蜂窝夹芯结构的力学性能,对复合混凝土材料蜂窝夹芯板研究及应用趋势进行总结。

一种麦秸纤维替代木粉制备的景观用复材特性研究

为提高园林景观建筑材料的环保性、强度和耐水性等,试验以麦秸纤维代替传统木粉,并加入剑麻纤维,制备了一种木塑复合材料(WPC),并对其性能进行研究。试验结果表明,麦秸纤维可以代替木粉制备WPC,制备出的WPC力学性能相差不大;剑麻纤维的掺入,可以提升WPC的力学性能和耐水性;当掺20 phr麦秸纤维、5 phr长度5 mm的剑麻纤维时,试验制备的WPC材料弯曲、拉伸强度分别达到53.6、16.8 MPa,弯曲弹性模量为4200 MPa,吸水率低于7%,材料具备较好的强度性能,韧性和耐水性良好。试验制备的木塑复合材料综合性能良好,可以作为园林景观建筑材料实际应用。