摩擦纺荨麻包芯纱的纺制及工艺研究

荨麻纤维是一种野生的天然纤维,属于麻类纤维的一种,目前国内外对荨麻纤维的开发和利用还处于起步阶段.分析了荨麻纤维的可纺性,开发出了以荨麻纤维和亚麻短纤维为包覆纤维、涤纶短纤维为芯纱的摩擦纺包芯纱,并利用正交试验,研究了纺纱速度、摩擦辊转速以及芯纱比例对纱线性能的影响,优选出荨麻纤维摩擦包芯纱的纺纱工艺范围.     

涤纶短纤维包芯纱粗纱的生产

包芯纱是以长丝为纱芯、外包短纤维的复合纱,一般是在细纱机上完成两种纤维的包覆.某纺织企业采用日本尤尼吉可公司、德国SKF联合研制的FL -6改进型粗纱机,在粗纱机上完成以涤纶短纤维为纱芯、外包棉纤维的包芯纱纺制,填补了纺制包芯纱的一个技术空白,提供了一种新的开发高档面料的纺纱形式.     

包芯纱捻系数的作用

绪言为了使产品适应多种用途的需要,促使纺纱新技术的发展,包芯纱即是其中之一。包芯纱用短纤维作纱芯是不常见的,最普遍的是用长丝作纱芯,用粘胶、天然棉等短纤维包覆制成。纺制包芯纱的主要目的在于使成纱兼有纱芯、皮层两种成分的优点。     

亚麻短纤维在纺织工业中的合理利用

在高档品种的细纱和织物中使用亚麻短纤维是一项非常重要而现实的任务。根据我们的研究,用亚麻短纤维可以纺得高质量的包芯纱,包芯纱中,亚麻短纤维处于外层缠绕在坚牢的化纤芯纱上(卡普隆,拉夫桑,强力粘胶丝等等),通过拈合的方法使其紧固起来。这种细纱可以做为经、纬纱用在一系列重要工业用的亚麻     

两种包芯纱的工艺优选及质量对比

探讨传统环锭纺包芯纱与赛络纺包芯纱的细纱工艺参数优化及芯纱包覆效果、成纱质量对比。细纱工序选择钳口隔距、后区牵伸倍数和捻系数进行三因子三水平正交试验,对条干CV、强力、毛羽等成纱质量指标进行测试,得出条干CV值的优化工艺为:钳口隔距3.5mm,后区牵伸1.39倍,捻系数402。对传统环锭纺包芯纱与赛络纺包芯纱的芯纱包覆效果与成纱质量指标进行对比分析,结果表明:传统环锭纺包芯纱的包覆效果、成纱质量均优于赛络纺包芯纱。认为:无论是纺制传统环锭纺包芯纱还是赛络纺包芯纱,都应控制好芯纱的喂入位置,从而保证良好的芯纱包覆效果。     

亚麻短纤维摩擦包芯竹节纱的开发

在DREF-Ⅲ型摩擦纺纱机上,以亚麻短纤维为外包纤维、涤纶短纤维为芯纱、棉纤维为竹节纤维,开发亚麻短纤维摩擦包芯竹节纱产品,探索该类产品的纺纱工艺及规律。     

UHMWPE复合纱的纺制及性能测试

UHMWPE纤维具有较高的比强度和比模量,但纤维吸湿性差。文章以黏胶短纤维为外包纤维,UHMWPE短纤纱(14.75 tex)及长丝(16.67 tex)为芯丝分别纺制34 tex包芯纱。以黏胶短纤维为中间纤维,UHMWPE短纤纱(14.75 tex)及长丝(16.67 tex)为包缠纤维分别纺制34 tex赛络菲尔纱。通过改变UHMWPE短纤纱或长丝与须条的间距优化赛络菲尔纱的性能,并对成纱性能进行测试和对比分析。结果表明:相同线密度纱线,以UHMWPE长丝为芯丝或包缠纤维所纺的包芯纱和赛络菲尔纱除断裂伸长率外,在强度、条干及毛羽方面均优于以UHMWPE短纤纱为芯丝或包缠纤维所纺的包芯纱和赛络菲尔纱。在纺制赛络菲尔纱时,UHMWPE短纤纱与须条的间距以8 mm为较优,UHMWPE长丝与须条的间距以6 mm为较优。     

亚麻/粘胶摩擦纱织物性能的研究

试验研究了亚麻 粘胶摩擦纱和摩擦包芯纱的平纹织物的性能 ,并将它们与亚麻 粘胶环锭纱织物以及纯棉环锭纱平纹织物的性能进行了比较和分析。结果表明 ,以涤纶长丝为芯丝的亚麻 粘胶摩擦包芯纱织物具有良好的服用性能。     

苎麻芳纶摩擦纺包芯纱工艺与性能浅析

为了探讨苎麻纤维、苎麻纱碱处理对苎麻芳纶摩擦纺包芯纱和复合纱性能的影响，采用室温碱法对苎麻纤维、苎麻纱进行处理；并介绍了高强高模的连续芳纶纤维作为芯纱，苎麻芳纶摩擦纺包芯纱的工艺。对比分析了碱处理后包芯纱和混和纱性能的变化。经测试认为碱处理降低了复合纱的性能，而增加了苎麻芳纶摩擦纺包芯纱性能。     

包芯纱的纺制

文章介绍了包芯纱的前景;论述了包芯纱可以充分发挥短纤维和长丝的长处,弥补各自的缺点;分析了包芯纱分类方法;描述了两种包芯纱装置的特性及有关安装、传动、张力控制、芯纱定位等注意事项;重点阐明了包芯纱的纺制关键、纱疵防治及产品开发。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.