浅析棉纤维成熟度对染色工艺的影响

通过对棉纤维成熟度差异与染色结果的分析,说明未成熟纤维含量是影响纤维染色性能的关键因素.     

原棉未成熟纤维含量与成纱质量

棉纤维的成熟度、原棉的未成熟纤维含量是影响原棉短绒率、疵点的关键,棉纤维的成熟度、原棉未成熟纤维含量主要因素是由棉花的栽培条件决定.分析了原棉未成熟纤维含量与清梳工序半制品质量和精梳工序质量的关系,原棉中的未成熟纤维必须在配棉、清梳和精梳工序进行控制,才能控制梳棉条、精梳条和成纱质量.原棉未成熟纤维含量不仅影响梳棉条、精梳条的短绒率、棉结、带纤维籽屑等疵点,而且严重影响成纱的各类主要疵点.     

AFIS成熟度测定在棉纱加工中的应用

棉纤维的成熟度和细度一直被看作讨论问题的基础，因为这两项指标在很大程度上决定了织物的染色性。一、AFIS长度及成熟度模块测定纤维成熟度及细度的传统气流式测定仪只测定棉花样品的平均值，且样品的敞露及污染对测定值还有显著影响。而AFIS长度及成熟度模块的应用，第一次提供了不仅测定单纤维长度，而且测定成熟度及其变差的可能。与此同时，还可测定出未成熟纤维含量（IFC）及纤维细度，及其变差。未成熟纤维含量是一种新定义的参数，它标明样品中未成熟纤维含量百分率（IFC）。充实度低于25％的纤维被定义为未成熟纤维．未成熟…     

棉纤维成熟度及其重要性研究

棉纤维的成熟度影响原棉的质量和轧棉、清梳加工中产生的棉结数量 ,是最终影响漂染后织物外观的关键要素。成熟度较好的棉纤维一般具有较高的强力和较好的回弹性。未成熟的棉纤维强力较弱 ,在轧棉和纺纱过程中容易断裂 ,因而降低了纤维的平均长度 ,增加了短纤维含量。由于未成熟棉纤维刚度较差 ,原棉中含有的未成熟棉纤维是形成棉结的原因之一 ,从而使纱线外观毛茸和条干不均匀。同时加工未成熟棉纤维时 ,废棉增多 ,纱疵增多 ,纱线强力降低 ,织造效率下降 ,因而影响最终织物的外观和质量。( 1 )成熟度影响染整加工棉纤维成熟度影响丝光、染…     

原棉混配与织物外观质量的关系

通过棉纤维成熟度，纤维细度对纤维在水中膨化作用和毛细吸收效应影响的分析，提出：纺织生产的用棉混配中原棉的不同品种，产地，未成熟纤维的含量和马克隆值的差异是导致纺纱织布染色后出现染色不匀和横档疵点的关键因素，进一步提出，严格控制混配棉条件是减少染色不匀和横档疵点的前提。     

未成熟纤维去除的研究

用Uster AFIS单纤维测试系统分别对3种梳针刺辊和1种锯齿刺辊在2档道夫转速和4档刺辊转速条件下两次试验所加工的生条未成熟纤维含量进行了测试，结果显示，在清花过程中，未成熟纤维含量是增加的，而在梳棉过程中，未成熟纤维含量有升有降，刺辊种类与未成熟棉纤维去除有一定的关系。     

影响成纱毛羽的原棉物理指标分析探讨

通过对影响棉纱毛羽的设备、纺织器材的阐述，分析了影响棉纱毛羽的关键是棉纤维的短绒率、细度、长度、整齐度、成熟度、未成熟纤维百分率、疵点、含糖量等，打破了传统观念认为毛羽产生的主要原因来自纺纱设备和纺织器材的观念，找到了解决纱线毛羽的途径主要是解决棉纤维物理特性。     

刺辊转速对生条中未成熟纤维去除的影响

为探讨刺辊转速对生条中未成熟纤维去除的影响,采用USTER AFIS单纤维测试仪对10档刺辊转速条件下所加工的生条进行了未成熟纤维含量的检测,结果显示:与棉卷相比,生条中未成熟纤维含量减少,纤维细度变粗,成熟度比变大;刺辊转速为800 r/min时,最有利于未成熟纤维的去除,刺辊转速为1 500 r/min时,最不利于未成熟纤维的去除;刺辊转速为1 300 r/min时,生条中纤维的细度最粗,刺辊转速为800 r/min时,生条中纤维的成熟度最大。     

中腔胞壁对比法测棉纤维成熟度的拓展

０　引言棉纤维在生长过程中，先是长度增加，然后胞壁加厚。在胞壁加厚的过程期间，长度一般不再增加，而是纤维素沿胞壁沉淀加厚。所谓棉纤维成熟度实际上是指纤维胞壁加厚的程度，胞壁愈厚，成熟度愈好。棉纤维成熟度与棉花品种、生长条件有关，特别受生长条件的影响。除长度以外，棉纤维的各项性能几乎都与成熟度有着密切的联系。正常成熟的棉纤维，截面粗，强度高，弹性好，有丝光，并有较多的天然卷曲。棉纤维成熟度的高低还与纺纱工艺、成品质量关系十分密切，如：成熟度高的棉纤维在加工过程中飞花和落棉少，成品制成率高；成熟度高…     

对棉纤维成熟度问题的讨论

棉纤维的成熟度对纺纱质量的影响极大，特别不成熟纤维含量越多会使纱线上的棉结增多，从而使纱线和织物的外观粗糙而不均匀，成纱强力也因为不成熟纤维的增多及所造成的短绒增加而降低，使得织造效率降低。此外，还由于不成熟纤维分布不均匀，会造成织物的横挡疵点，影响成品织物的外观，因此，棉纤维的成熟度应做为纺纱混配棉的重要控制指标。同时也要应用先进的检测仪器进行逐包检验，并控制与掌握不成熟纤维含量及分布，以稳定与提高产品质量。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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.     

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.     

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.