Measurement of Fibre Tuft Weight in an Air Duct using Optical Methods

The feasibility of using a Charge-Coupled Device (CCD) linescan camera to evaluate the weight of fibre tufts moving in an air duct is reported. A theoretical study of the measurement of the light transmission of fibre tufts is presented and the theoretical models are verified by experimental results. The accuracy of the results is improved by a modification of the air duct shape. The fibre tuft speed and the optical uniformity are also discussed.     

关于桑蚕丝茸毛的研究

对桑蚕丝茸毛成因从原料至缫丝条件等进行多项试验,并对正常茧丝和茸毛纤维作离子刻蚀,观察、验证了茸毛纤维不易上色的机理,并提出茧丝良好组合和保护丝胶、提高茸毛分级度的见解。     

Some Textile Applications of Finite-element Analysis Part I: Finite Elements for Aligned Fibre Assemblies

A new approach to the application of finite elements to aligned-fibre-assembly problems is introduced. This more rigorous application of finite-element analysis will allow the solution of a range of problems that have been impossible to solve by using previous approaches. Difficulties with non-linear material properties and large-scale deformations are overcome by defining the element stiffness matrix in a co-ordinate system based on the energy modes of the element deformation. It is shown how algorithms can be used to supply non-linear relationships for various types of deformation, simplifying the task of using complex material properties. The transformation of the element properties back to a conventional co-ordinate system to allow assembly of all of the elements in the structure is presented.

A two-dimensional element is developed to model aligned fibre assemblies. To maintain fibre continuity between finite elements, twelve degrees of freedom are required for each element. The deformation modes of this element are derived in terms of the conventional co-ordinate system. The results from the finite-element analysis are compared favourably with measurements taken from a deformed array of springs.

This paper is the first part of a series of two papers. Part II will investigate the application of finite elements to yarn mechanics.     

钢筋钢纤维增强部分砼梁裂缝宽度的试验研究

钢纤维砼应用于钢筋砼构件 ,能显著提高构件的抗弯、抗剪及延伸性能 .选取 8根试验梁进行了正截面受弯性能试验 ,通过钢纤维对平均裂缝间距、钢筋应变不均匀系数和钢筋应力的影响分析 ,提出了正常使用条件下与普通钢筋砼梁最大裂缝宽度的计算方法相衔接的钢筋钢纤维增强部分砼梁裂缝宽度的计算方法 .结果表明 ,部分地加入钢纤维的砼梁构件能达到全截面增强的效果 .实际应用中能显著减少钢纤维的用量 ,具有较好的经济效益 .     

Effects of fibre parameters on the ultraviolet protection of fibre assemblies

Ultraviolet (UV) radiation protection is becoming increasingly necessary for human health, and textiles play an important role. The interaction between UV light and textiles is a complex one, involving fibre, yarn and fabric parameters. In this study, an optical model is presented for examining the influences of fibre parameters on the UV protection offered by a bundle of fibres with a given mass. The effects of mean fibre diameter and fibre type on UV absorption were examined. The model was verified with results of UV–visible diffuse reflectance measurements on natural and synthetic fibres. When the mass of fibres was kept constant, within the measurement range in this study, a bundle of fibres with coarser fibres had a lower UV reflectance than that with finer ones. The model accurately predicted factors influencing UV protection, including fibre diameter, fibre transmittance, porosity and refractive index.     

Bioactive compounds from hazelnut skin (Corylus avellana L.): Effects on Lactobacillus plantarum P17630 and Lactobacillus crispatus P17631

Hazelnut skins are a good example of agro-food by-products, potentially source of natural antioxidants and functional food ingredients, rich in polyphenols and dietary fibre. The chemical characterization performed in our study confirmed that fibre is the main component of hazelnut skin. Moreover, four different polyphenols-rich extracts and two fibre fractions were obtained by the processing of the skins. The functional activity of these extracts was verified using them as ingredients in media employed for the growth of two probiotic strains (Lactobacillus plantarum P17630 and Lactobacillus crispatus P17631). Starting from 0.01% (w/v), both soluble (SDF) and insoluble dietary fibre (IDF) significantly improved the bacterial growth during fermentation toward control. Both SDF and IDF showed a considerable increase in cryoprotection during lyophilisation, showing a similar effect to the inulin at the same concentration. Finally, we suggest this matrix as source of new functional fibres both for foods and nutraceutical products containing probiotic bacteria.     

Modelling local bending stiffness based on fibre orientation in sawn timber

Strength of structural timber depends to a high degree on the occurrence of knots and on the local fibre deviation around such defects. Knowledge of local fibre orientation, obtained by laser scanning, has been utilized in a previously developed machine strength grading method, but rather crude assumptions regarding the fibre orientation in the interior of boards and a mechanical model that does not capture the full compliance of knotty sections were adopted. The purpose of the present study was to suggest and verify a model with which local bending stiffness can be predicted with high accuracy. This study included development of a model of fibre orientation in the interior of boards, and application of a three-dimensional finite element model that is able to capture the compliance of the board. Verification included bending of boards in the laboratory and application of digital image correlation to obtain strain fields comparable to those obtained by finite element simulation. Results presented comprise strain fields of boards subjected to bending and calculated bending stiffness profiles along boards. Comparisons of results indicated that the model suggested here was sufficient to capture the variation of local bending stiffness along boards with very high accuracy.     

抗性淀粉对馒头的感官评价及物性的影响

抗性淀粉的特性与膳食纤维基本相似,但它又不同于膳食纤维。抗性淀粉添加到食品中后,它不会像膳食纤维那样影响食品的感官和质构。但当较高含量的抗性淀粉添加于小麦粉中,在一定程度上恶化了小麦粉的加工性能。实验证明：将中筋粉中添加5%左右的抗性淀粉制作馒头,既可保证馒头的保健品质又不失其食用品质及感官品质。     

优化纤维素酶水解桃渣制备可溶性膳食纤维工艺条件的研究

以工业化生产桃汁的废弃榨渣为原料,通过纤维素酶酶解制备可溶性膳食纤维,以获得高得率的可溶性膳食纤维的。先通过单因素实验初步确定了制备工艺条件,再根据Box-Benhnken的中心组合实验设计原则,在单因素实验的基础上采用3因素3水平的响应面分析法,建立了可溶性膳食纤维得率与各影响因子的回归方程,并确定了加酶量1.25%、温度45℃、pH4.5的工艺条件,在此条件下可溶性膳食纤维的理论得率达20.68%,验证实验结果为20.56%。     

A Study of Various Mechanisms of Attrition of Fibres as a Result of Abrasion

This paper presents an account of an experimental study of the pure-bending and recovery properties of both continuous-filament and spun yarns. The bending behaviour of yarns is approximately represented by a simple two-element rheological model of an elastic element and a single frictional element acting in parallel. The use of this model allows the bending deformation to be separated into an elastic and a frictional component, measured by the flexural rigidity and the frictional (or coercive) bending moment, respectively. An expression for the frictional couple in yarn-bending is derived from consideration of the lateral forces acting within the yarn and the degree of set of fibres in a twisted yarn. Bending experiments were made with nylon model plied yarns, conventional multifilament yarns, and staple-fibre yarns; it is shown that the level of residual fibre tension within both unset and set yarns can be estimated from the experimental values of the frictional bending moment by semi-empirical means. The mechanisms of bending for conventional polyester-fibre multifilament and worsted-spun yarns are investigated and the effects of yarn linear density, twist, and yarn-setting treatment studied. The bending behaviour of a series of wool-nylon blended-fibre yarns is also discussed in terms of the simple two-element rheological model of yarn-bending behaviour. It is shown that both the flexural rigidity and the frictional bending moment for the blended-fibre yarns can be calculated by assuming independent behaviour of the fibre during bending.     

Understanding the influence of fibre,yarn and fabric parameters on UV protection of wool-knitted fabrics

This work investigated the influence of fibre, yarn and fabric parameters on the UV protection of fabrics. It proposed a model for UV interaction based on a theoretical hypothesis, targeted experimentation and statistical analysis. Undyed and untreated wool-knitted fabrics with varying mean fibre diameter, yarn linear density, yarn twist, fabric cover factor and fabric structure were examined. A statistical model was presented to report the relationship between fibre/yarn/fabric parameters and fabric UPF values. An optical model on the interaction between the UV light and a single jersey fabric was constructed to understand the penetration of UV light. The models were verified by the UV transmittance results of knitted wool fabrics. The results obtained from the statistical and optical models were used to propose a set of optimized parameters for lightweight summer/spring UV-protective knitted fabrics. Testing confirmed that these fabric parameters provided both high UV protection and good tactile comfort.     

Variabilität der Faserneigung im Holz der Esche (Fraxinus excelsior L.) und Douglasie (Pseudotsuga menziesii (Mirb.) FRANCO)

The central aim of this project was the quantification and the analysis of the components of variation of the fibre angle in wood of Ash-as example for ringporous broadleaved species-and of Douglas fir—as example for coniferous species-as well as the review of the accuracy and representativity of a oftenly used method on log discs, which consists in the determination of the average of two diametral opposite values of fibre angle within one growth ring. The annual fibre angle was determined on 32 radii of six disc samples of Ash and Douglas fir with a specially designed protractor constructed at the Department of Forest Utilization of the University in Göttingen. The obtained results show a significant tangential variation of the fibre angle within one annual growth ring, which is at least as pronounced as the radial interannual variation, which is already well known from other investigations. In addition, small but significant differences were observed between the fibre angle values of earlywood and latewood of the same annual growth ring. It follows from these three observed variation components that this investigated method can be only used in limited cases for douglas fir and Ash. The observed overlapping of these variations is an important element of uncertainty for the data analysis, which makes more difficult the interpretation of causal relations between growth conditions, age etc. and fibre orientation in wood.     

纤维悬浮液的数值模拟研究

本文回顾了纤维悬浮液模拟的方法，并对模拟的方法进行了简单的探讨，主要包括Ewald求和模拟技术，使用摩擦力考虑了短范围的作用力和微小体近似来考虑长范围作用力，还有BCF和适合粘性分离应力（AVSS）的有限元公式的结合。数字模拟的结果被平均来评价悬浮液的宏观流变特性。     

Tencel织物的染整工艺研究

Ｔｅｎｃｅｌ纤维被誉为二十一世纪的绿色纤维,它是一种再生纤维素纤维,但其染整加工特性与传统的纤维素纤维又有所不同,控制纤维的原纤化可以使织物获得独特的风格。     

Needleless electrospinning: influences of fibre generator geometry

The fibre generator shape and dimension are key factors affecting the needleless electrospinning process and fibre fineness. In this work, cylinder with rounded rim, disc and ball were used as spinnerets to electrospin polyvinyl alcohol and polyacrylonitrile solutions. A finite element method was used to analyse how the spinneret geometry affected the electric field generated during electrospinning and the associated changes in fibre diameter and productivity. For cylinder spinnerets, increasing the rim radius reduced the discrepancy of electric field intensity between the cylinder end and middle area, which affected the fibre productivity. The electrospinning failed to operate when the rim radius was over 20?mm. With decreasing cylinder diameter, the electric field intensity in the middle area increased, improving the fibre productivity. Thinner disc spinnerets increased the electric field intensity, resulting in finer nanofibres and higher productivities. Ball spinnerets produced evenly distributed electric field, but failed to electrospin fibres when the diameters were below 60?mm. It has been found that strong and narrowly distributed electric field in the fibre-generating area can significantly facilitate the mass production of quality nanofibres.     

成纱毛羽的影响因素及控制措施

探讨影响环锭纺纱毛羽的因素及控制措施.通过分析纤维长度和细度,清棉、梳棉、精梳落棉,粗纱捻度.细纱锭子速度、钳口大小、钢领、钢丝圈,络筒工艺参数对成纱毛羽的影响,指出:环锭纺纱毛羽的产生与纺纱原料、工艺配置、纺纱专件使用状况等诸多因素有关,其重点在细纱和络筒.减少毛羽首先要合理配棉,控制好原料细度和短绒;合理配置前纺工艺及落棉,控制半成品短绒含量;正确选配粗纱捻系数、细纱速度、钳口等工艺参数;合理选配和使用钢领、钢丝圈;选用金属槽筒并合理配置络筒速度和张力,可使成纱毛羽得到有效的控制.     

Dietary fibre in human nutrition

Is vegetable fibre a necessary constituent of the diet? Certain diseases, largely colonic are more prevalent in western countries. Epidemiological studies suggest that this is a consequence of the low fibre content of the diet. The main action of fibre is in the colon. An approach to fibre studies is by defining physical characteristics in fibre which could alter colonic function. It is only when the chemistry of fibre is better defined that meaningful relationships between fibre constituents and disease can be made.     

涤纶织物接枝改性的研究

研究了DMF处理时间、电晕处理时间、接枝共聚时间、温度和单体浓度等各种条件对接枝率的影响;通过ESCA（化学分析用电子光谱学）技术分析了织物表面元素和官能团的变化,采用SEM（扫描式电子显微镜）观察织物表面形态。结果表明,接枝反应仅发生在纤维表面,织物改性后的回潮率随着接枝率的增大而增加。     

醋酸乙烯丙烯共聚浆料的新进展

在醋酸乙烯丙烯共聚浆料基础上研制开发了由醋酸乙烯、丙烯酸酯、丙烯酰胺、丙烯酸和丙烯腈五元共聚合成的AE01浆料。介绍了制备AE01浆料的原理、方法，用红外光谱分析法验证了五种单体的特征峰，对AE01浆液与浆膜性能进行了测试，并在涤棉混纺品种与原醋酸乙烯丙烯共聚浆料进行了上浆及织造效果对比。认为AE01浆料的成膜性及耐磨性优于醋酸乙烯丙烯共聚浆料，适宜于对疏水性纤维纱进行上浆。     

Processing of waste carbon and polyamide fibres for high-performance thermoplastic composites: influence of carding parameters on fibre orientation,fibre length and sliver cohesion force

Abstract

The processing of waste carbon fibre on carding machine for the developments of nonwovens, tapes and hybrid yarn structures is an emerging trend. These structures are widely used to enhance the performance efficiency of recycled carbon fibre reinforced thermoplastic composites. The aim of the research presented in this study is to process waste carbon fibre on a carding machine and to investigate the influence of different carding parameters on waste carbon fibre. For this purpose, card slivers composed of waste carbon and polyamide fibres were developed on a double cylinder card machine by varying technical parameters. Then, effect of these parameters on card sliver quality was assessed in terms of fibre orientation, fibre length and sliver cohesion force. Results revealed that fibre orientation and fibre length is significantly affected by technological parameters carding zones, whereas the sliver cohesion force is significantly affected by the speed of feed roller and doffer.