Contactless optical extensometer for textile materials

In this paper we present a contactless extensometer. For some flexible materials, with great displacements and deformations, contact during measurement is not acceptable. In fact, contact measurement can modify the tensile behavior, as is the case for fibrous materials. Contactless extensometers usually have to print or glue some marks on the sample, which may cause problems during measurement. These extensometers typically use digital image processingto obtain deformation data. The principle used in this study uses the natural periodicity or surface patterns inherent in most textile materials without any image processing. During deformation the distance between two periods or pattern elements changes, allowing this method to measure the real-time modification of this in-plane distance. The extensometer consists of two parts: an optical device and a signal processing unit performing a Fourier analysis. Some results obtained during a tensile test on woven fabrics and non-wovens are presented here.     

两步辐射接枝法制备抗熔滴涤纶织物

以涤纶(PET)为基材,利用两步γ辐射接枝法在PET织物表面依次引发甲基丙烯酸缩水甘油酯(GMA)/二乙烯苯(DVB)和乙烯基磷酸二甲酯(DMVP)接枝共聚,制备了新型抗熔滴PET织物.接枝率随吸收剂量和单体浓度的增加而增加,随剂量率增加而下降.傅里叶红外(FTIR)、X射线光电子能谱(XPS)和热重分析(TGA)的分析结果表明在PET织物上成功引入目标接枝聚合物.相比PET织物,辐射改性PET织物的拉伸强度以及断裂伸长率均有所提高.通过引入交联网状结构以及促进成炭的含磷接枝聚合物,PET织物的抗熔滴特性得到了明显改善,燃烧过程中平均产生一滴熔滴的时间:PET为3.0 s/n,PET接枝PGMA/DVB后延长为17.0 s/n,而进一步接枝PDMVP后在整个燃烧过程中均不产生熔滴.这种新型的方法有望用于PET织物防护服抗熔滴性能的改善.     

Fixation of Some Direct Dyes on γ-Irradiated Nylon-6 Fabrics Through Treatment with Cyanuric Chloride

Cyanuric chloride was utilized as a crosslinking agent in forming a chemical linkage between some direct dyes and the available sites in the macromolecular structure of nylon-6. This chemical treatment was carried out on nylon-6 fabrics before and after being γ-irradiated in air with different radiation doses. The so-called dye fixation of three direct dyes, which contain at least one amino group in their chemical structure, was assessed in terms of extraction in 50% aqueous solution of N, N-dimethylformide. It was found that the dye fixation of the direct dyes under investigation depends essentially on the cyanuric chloride concentration. However, low concentrations of 1% were found to be sufficient to produce good dye fixation. Moreover, nylon-6 fabrics when irradiated prior to dyeing and treatment acquire additional dye fixation. The pH of the dyeing bath and the added solvents were found to play a specific role in the dye fixation process. © 1997 John Wiley & Sons, Ltd.     

Mechanical behavior of non-crimp fabric PEEK/C thermoplastic composites

The thermoplastic resin Poly-Ether-Ether-Ketone (PEEK) was used to develop four new NCF composite materials. They refer to two different principal concepts, while each concept was investigated for two different material modifications. The tensile and compression behavior of the newly developed NCF materials was experimentally investigated. For comparison, same tests were also performed on APC-2/AS4 reference material. Prior to the mechanical tests, the quality of the produced laminates was evaluated by means of non destructive investigation (C-Scan tests) and optical microscopy analyses to obtain defects such as delaminations, porosities, micro-cracks etc. The results of the mechanical tests were exploited to obtain the “optimal” NCF fabrication process; the mechanical properties of the material solution considered to be “optimal” compare well to the respective properties of the reference material thus providing evidence for improved cost efficiency by the production of thermoplastic composite components.     

A comparative study of different cellulase preparations in the enzymatic treatment of cotton fabrics

Twenty-nine cellulase preparations from different sources were compared interms of their abrasive activities (the ability to remove Indigo from denim) and their ability tosaccharify cellulose. Nodirectrelationship could be found between these two abilities. The preparations were divided into three groups: (1) with a high yield of reducing sugars after 24 h hydrolysis of Avicel cellulose but low abrasive activity; (2) universal cellulases that could both effectively hydrolyze cellulose and remove Indigo from denim; and (3) cellulase samples with high abrasive activity but low saccharification ability. Cellobiohydrolase (CBH) and xylanase were purified from different fungi by chromatofocusing on a Mono P column and subjected to limited proteolysis with papain yielding cellulose-binding and core (catalytic) domains. The adsorption ability and backstaining index of both CBH and xylanase core proteins were notably lower than the respective parameters for the in itial nondigested enzymes indicating that protein adsorption on the surface of cotton fibers is a crucial factor causing Indigo backstaining during the enzymatic denim washing procedure.     

Influence of surface activation by plasma and nanoparticle adsorption on the morphology, thermal stability and combustion behavior of PET fabrics

Plasma surface activation at different process parameters (namely, power and etching time) has been combined with nanoparticle adsorption (i.e., a natural montmorillonite) in order to improve the thermal stability and flame retardancy of PET fabrics. Scanning electron microscopy coupled to elemental analysis has put in evidence a direct relationship between the distribution of nanoparticles on fibers and process parameters. The presence of the above nanoparticles affects the thermal stability of fabrics in air, as assessed by thermogravimetric analysis: a delay of the mass loss process has been observed for the treated samples.Combustion behavior has been investigated by cone calorimetry: plasma activated fabrics have shown a remarkable improvement in terms of time to ignition (up to 104%) and a slight reduction of the heat release rate (ca. 10%) as compared to neat PET.     

Jute fiber-reinforced chemically functionalized high density polyethylene (JF/CF-HDPE) composites with in situ fiber/matrix interfacial adhesion by Palsule Process

Jute fiber-reinforced chemically functionalized polyethylene high density (JF/CF-HDPE) composites have been processed, by Palsule process without using any compatibilizer and without any fiber modification, by using chemically functionalized maleic anhydride grafted polyethylene (MAPE) as matrix, in place of polyethylene. Fiber/matrix interfacial adhesion generated in situ, due to interactions between jute fiber and the maleic anhydride of the CF-HDPE matrix, has been established by Fourier transform infrared spectroscopy and scanning electron microscope micrographs. Mechanical properties of the JF/CF-HDPE composites developed with in situ fiber/matrix interfacial adhesion in this study have been found to be higher than those of the CF-HDPE matrix and increase with increasing amounts of jute fibers in the JF/CF-HDPE composites, and are better than properties of literature reported and laboratory processed jute fiber/polyethylene composites with and without MAPE compatibilizer. Measured tensile modulus of JF/CF-HDPE composites compares well with values predicted by rule of mixtures, inverse rule of mixture, Hrisch Model, Halpin-Tsai equations, Nielsen equations, and with Palsule equation. The feasibility of developing natural fiber/maleic anhydride grafted polyolefin composites by Palsule process without using any compatibilizer and without any fiber treatment is demonstrated.     

Novel Synthetic Pathways for Bis(acyl)phosphine Oxide Photoinitiators

Photoactive: A cheap, safe, and widely functional-group-tolerant synthetic protocol to an important class of photoinitiators, bis(acyl)phosphine oxides (BAPOs), has been disclosed, together with examples of application to stain-proof fabrics and photoactive polymeric films.     

废旧涤/棉混纺织物近红外定量分析模型的建立及预测

将中红外光谱筛选出的598个纯涤、纯棉及涤/棉混纺样本采用GB/T 2910.11-2009法测定其涤、棉准确含量,其中校正集样本252个,验证集样本346个。使用便携式近红外光谱仪获取样本的原始近红外光谱(NIRS)。校正集样本依据回归系数的分布趋势和范围选取最佳建模谱区,并采用差分一阶导、S-G平滑和均值中心化相结合的方法对原始光谱进行预处理,利用偏最小二乘法(PLS)建立涤/棉混纺织物中涤含量的近红外(NIR)定量分析模型。同时分析了样本颜色对NIRS的影响,探讨了斜线光谱样本、奇异样本和不同组织结构织物对模型预测效果的影响。结果表明:利用PLS法建立的涤/棉混纺织物定量分析模型最优组合包含1个光谱区间和9个主成分因子,校正集相关系数(RC)为0.998,标准偏差(SEC)为0.908。为验证所建模型的有效性和实用性,对346个未参与建模的涤棉样本进行了预测,并将预测结果与国标法测定值进行方差分析,两种方法结果无显著差异,预测正确率达97%以上。模型的建立为废旧涤/棉混纺织物快速、无损分拣提供了基础数据库。     

LC-GC analysis of the aromatics in a mineral oil fraction: Batching oil for jute bags

Aromatics of a C₁₅? C₃₀ mineral oil fraction, the “batching oil” used for producing jute fabrics, were analyzed for estimating the toxicity of oil transferred from jute bags to foods. Group-type pre-separation according to ring systems occurred on a LC NH₂ column with pentane and small additions of methanol as eluent. LC fractions were characterized by LC-GC-MS and quantitated by LC-GC-FID. The oil contained 23% aromatics and 1% “polars”; some 99.5% of the aromatics were alkylated.