细纱机前区加装压力棒纺制特细号纱的实践

探讨细纱前区加装压力棒的纺纱效果及工艺配置问题.在FA503型细纱机上对配置压力棒隔距块纺制CJ 7.4 tex特细号纱的质量情况进行了试验,结果表明:使用压力棒隔距块有利于提高成纱质量,压力棒隔距块钳口大小直接影响纺纱效果,适当增加细纱后区牵伸倍数和减小粗纱捻系数对成纱质量影响不大.指出使用压力棒隔距块时钳口应比普通隔距块加大0.25 mm～0.5 mm,为保证正常牵伸,可适当增大细纱后区牵伸倍数或减小粗纱捻系数.     

牛奶蛋白纤维氨纶包芯纱的生产

为了顺利生产牛奶蛋白纤维氨纶包芯纱,对各工序纺纱工艺参数进行了优选.生产前对牛奶蛋白纤维进行预处理,清梳工序采用低速度、大隔距、多梳少打、均匀混和、快转移、小张力的工艺原则,并条采用顺牵伸,粗纱适当加大捻度、减少后区牵伸倍数,细纱采用重加压、大后区隔距、小后区牵伸、小钳口隔距等技术措施.措施实施后,成纱质量好,条干均匀.     

提高R 9.8 tex成纱质量的生产实践

为了提高R9.8 tex成纱质量,通过原料选配并对其进行纺前预处理以提高原料可纺性,优选各工序主要工艺参数配置,如棉卷定量、打手速度、梳理隔距、针布型号、并条牵伸工艺、粗纱捻系数、细纱罗拉隔距、纺纱胶辊、钳口隔距、后区牵伸等措施,最终使R 9.8 tex纱的成纱质量得到明显改善.     

提高CJ 11.7tex纱条干均匀度的工艺配置

在生产CJ11.7tex纱的基础上全面分析了细纱工艺与成纱条干均匀度的关系,并对影响成纱条干均匀度的关键工艺前区工艺参数、后区牵伸工艺进行了优化配置。实验结果证明:采用较小的粗纱定量、细纱捻系数、前中罗拉隔距、较小的钳口隔距、较小的后区牵伸倍数以及较大的前胶辊压力,采用较大前胶辊直径,适当增加粗纱捻系数等措施,可以提高成纱条干CV。     

基于超早熟短季棉的细纱牵伸工艺研究

通过改变粗纱捻系数、细纱后区罗拉隔距、后区牵伸倍数等工艺参数,研究了适于超早熟短季棉的细纱后区工艺.探讨了不同工艺参数对成纱断裂强度、纱线条干不匀率以及毛羽的影响.结果表明,粗纱捻系数、后区罗拉隔距、后区牵伸倍数对纱线断裂强度影响显著,后区牵伸倍数对纱线条干不匀率影响显著,后区罗拉隔距对纱线毛羽影响显著.研究得出了适于超早熟短季棉的最佳细纱后区工艺为:粗纱捻系数115,后区罗拉隔距30 mm,后区牵伸倍数1.29.     

细纱牵伸器材及工艺配置对成纱细节的影响

简要分析了成纱细节产生的原因,就细纱上销、胶圈、胶辊与集合器等关键牵伸器材以及加压牵伸形式、粗纱捻系数与细纱后区牵伸倍数等工艺配置对成纱细节的影响进行了试验分析.结果表明,将宽面钳口尼龙上销与新型下销进行配置、采用适当的胶圈张力、较小的钳口隔距、使用集合器、加大粗纱捻系数、减小细纱后区牵伸倍数并采用适宜的胶辊表面粗糙度,对控制成纱细节有利.     

提高CJ 11.7 tex纱条干均匀度的工艺配置

为了提高细纱条干均匀度,以生产CJ 11.7tex纱为基础全面分析了细纱工艺与成纱条干均匀度的关系,并对影响成纱条干均匀度的前区工艺参数、后区牵伸工艺进行了工艺配置试验。结果证明:采用较小的粗纱定量、细纱捻系数、较大的粗纱捻系数、较小的前中罗拉隔距、钳口隔距、后区牵伸倍数以及较大的前胶辊压力、前胶辊直径,适当增加粗纱捻系数等措施,可以改善成纱条干CV值。     

提高CJ11.7tex纱条干均匀度的工艺配置

在生产CJ11.7tex纱的基础上分析了纱线条干均匀度的影响因素。为了提高细纱条干均匀度,对影响成纱条干均匀度的前区工艺参数、后区牵伸工艺进行了工艺配置。实验结果证明,采用较小的粗纱定量、细纱捻系数、前中罗拉隔距、较小的钳口隔距、较小的后区牵伸倍数,以及较大的前胶辊压力,采用较大前胶辊直径,适当增加粗纱捻系数等措施,可以提高成纱条干CV值。     

改善过成熟原棉成纱条干的实践

为了改善过成熟原棉的成纱条干水平,减少成纱棉结,针对过成熟原棉细度粗、纤维整齐度差的特点,进行了纺纱工艺试验.开清棉工序要精细抓棉,减少打击点,各机打手速度偏小掌握;梳棉工序降低刺辊速度,增加盖板速度;并条工序合理配置牵伸倍数,提高纤维平行伸直度;粗纱工序采用较小牵伸倍数,较大粗纱捻系数;细纱工序减小后区牵伸倍数,采用附带压力棒的隔距块.通过调整工艺,选用新型专件器材,加强车间温湿度管理,使过成熟原棉成纱条干和棉结得到有效改善.     

后区纱条的控制对成纱质量的影响

从牵伸设计角度而言,目前细纱后区牵伸对纱条的控制仍存在弱点,针对这一现状,对比分析了牵伸型式、粗纱捻系数、罗拉隔距、后区牵伸倍数及新型上销对控制后区纱条的影响,说明后牵伸区采用V型牵伸比直线型牵伸的效果好;粗纱捻系数、后区罗拉隔距、牵伸倍数、采用新型上销等对后区纱条的控制都产生较大的影响,应根据不同工艺采用新型专件来提高成纱质量;肯定了后区工艺在纺纱中的重要作用.     

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.     

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.