天然彩色棉纺纱工艺实践

为了提高天然彩棉的成纱质量,针对天然彩棉纤维细度较细,马克隆值偏低,含杂略高的特点.在纺纱过程中,通过对各工序工艺进行优化调整,并采取了相应的技术措施.总结出在纺天然彩棉时,清棉工序应"勤抓少抓,多梳少打,充分混和",梳棉工序采用低刀小角度、适当降低刺辊速度,精梳工序加大落棉隔距,并条工序在总牵伸不变的情况下适当减小后区牵伸倍数,粗纱工序和细纱工序缩小主牵伸区罗拉隔距、适当减小细纱后区牵伸的工艺原则.从而提高彩棉成纱的质量水平.     

竹浆纤维混纺涡流纱的纺制

探讨竹浆纤维棉混纺涡流纱的生产工艺.针对竹浆纤维特点进行原料加湿预处理,较好地解决了生产中的静电现象.采用条混工艺以保证准确的混纺比.开清棉采用“短流程、多松少打、多梳少落”的工艺原则;梳棉采用“轻定量、低速度、紧隔距”的工艺原则,减少棉结和短绒;并条工序合理配置牵伸工艺;涡流纺工序对牵伸倍数、喷嘴压力、喷嘴与前罗拉隔距等工艺参数进行优选,最终顺利纺制出了竹浆纤维/棉70/3014.7 tex混纺涡流纱,质量达到了较好的水平.     

赛络纺森氧吧纤维混纺毛巾纱的生产

探讨了赛络纺森氧吧纤维混纺毛巾纱的生产要点。根据森氧吧纤维的特点,制定了各纺纱工序的工艺参数及主要技术措施。其中,清花采用多松少打工艺;梳棉生产时按"轻定量、低速度、小张力,大隔距"的工艺原则;并条宜采用较小的喇叭口;粗纱捻系数尽量偏大控制,以细纱不出硬头为准;细纱工序以减少毛羽为目标。结果表明:森氧吧纤维混纺毛巾在纺纱时宜采用低速度、重加压和适当加大捻度的方法。     

精梳棉桑皮纤维11.7tex混纺集聚纱的纺制

探讨纺制精梳棉/桑皮纤维60/40 11.7tex混纺集聚纱的工艺配置与技术要点。采取棉精梳条与桑皮纤维预并条进行三道混并的方法;对桑皮纤维适量添加油剂,防止静电的产生;开清棉适度打击、梳理、混和,保证成卷质量稳定;梳棉低速度、轻定量、紧隔距,清除桑皮纤维较多的杂质;细纱工序对DTM129型细纱机进行四罗拉集聚纺改造,并在细纱牵伸区中加装了压力棒隔距块,顺利纺制出精梳棉/桑皮纤维11.7tex混纺集聚纱。认为:采用集聚纺纱方法和压力棒式隔距块可使所纺制出的精梳棉桑皮纤维混纺纱条干均匀度较好、成纱毛羽较少。     

精梳棉Formotex纤维混纺竹节纱的开发

为纺制精梳棉Formotex纤维混纺竹节纱,根据Formotex纤维性能特点,合理选择工艺流程,清梳工序多松少打、多梳少落,优选速度、隔距等工艺参数,减少纤维损伤、提高棉网清晰度;并粗工序优选后区牵伸、罗拉隔距和粗纱捻系数,注重改善纱条均匀度;细纱工序合理选用胶辊、钢丝圈和集合器,控制毛羽和减少纱疵,最终使纺纱质量指标满足了使用要求.     

精梳纯彩棉纱的纺制

探讨精梳纯彩棉9.7 tex纱的纺制工艺。测试了棕色彩棉的纤维性能。介绍了精梳纯彩棉纱的纺纱工艺流程及各工序工艺技术措施。顺利纺制出精梳纯彩棉9.7 tex纱,质量指标达到较好水平。认为:通过合理选择工艺流程、配置工艺参数,可解决纯彩棉可纺性差的缺点,纺出品质优良的纯彩棉纱。     

精梳长绒棉超细腈纶eks赛络纺针织纱的生产

探讨精梳长绒棉/超细腈纶/eks 40/35/25 14.6 tex赛络纺针织纱的生产方法。介绍了长绒棉、超细腈纶和eks纤维的性能特点。根据三种纤维的性能特点和成纱质量要求,采用将超细腈纶与eks纤维原料混合纺制成预并条,再与精梳棉条进行三道混并条的混和方法,有效控制混纺比例;清棉工艺上,对细超腈纶和eks纤维纺纱采取"多松少打,多梳少落,低速度,大隔距"及防黏卷措施;梳棉工艺采取抬高给棉板,使用密封式小漏底,适当降低各部速度和放大锡林与盖板隔距等措施;并优化配置并条、粗纱、细纱和络筒等工序工艺参数;控制好各工序温湿度;顺利生产出精梳长绒棉/超细腈纶/eks纤维40/35/25 14.6 tex赛络纺针织用纱。认为:采取相应的技术和管理措施,可完成此产品的开发及满足质量要求。     

莫代尔甲壳素纤维喷气涡流纱的开发

探讨了莫代尔甲壳素纤维喷气涡流纱的生产工艺。测试对比了莫代尔、甲壳素纤维、粘胶三种纤维的性能特点,分析了纤维断裂强度和动、静摩擦因数等因素在纺纱过程中所起的作用。根据莫代尔、甲壳素纤维的性能特点,设计采用了"短流程,低速度,多松少打,充分混和,大隔距,轻定量,奇数准则,适当的喷嘴气压和稍低的出纱速度"的技术措施。最终成功开发出了具有抗菌抑菌、柔软舒适的莫代尔/甲壳素纤维70/3018.4 tex MVS混纺纱,且成纱质量较好。认为:采用与莫代尔混纺的方式,可以提高甲壳素纤维在喷气涡流纺设备上的适纺性。     

精梳亚麻棉混纺喷气涡流纱的工艺优选

探讨精梳亚麻棉混纺喷气涡流纱的生产工艺。围绕原料选配、前纺及涡流纺工艺配置进行了试验与优化,成功纺制出精梳亚麻/棉55/45 19.6 tex喷气涡流纱。认为:抓好亚麻原料预处理,正确设定原料投料比,合理配置前纺各工序的工艺参数,喷气涡流纺采用引纱速度200 m/min,喷嘴气压0.5 MPa的工艺配置,可以纺制出质量满足要求的精梳亚麻棉混纺喷气涡流纱。     

A100TS天丝赛络纺针织纱的纺纱实践

为提高A100TS天丝赛络纺针织纱的成纱质量,针对原料性能特点,在纺纱各工序进行了工艺参数的优化配置.开清工序适当降低各打手速度,合理配置各部隔距,加强开松和转移,减少纤维损伤;梳棉工序采用轻定量、低速度,加强纤维梳理和转移;并条工序采用重加压、轻定量、低速度、大隔距、合适并合,以利于条子牵伸;粗纱工序采用大隔距、小后区牵伸、小捻度工艺原则,改善粗纱条干均匀度;赛络纺工序采用较小的后区牵伸倍数,较小的钳口隔距,保证了纱线的条干均匀度;络筒工序采用低速度、小张力,优化清纱工艺参数.实践表明,优化配置纺纱各工序工艺,严格控制半成品质量,并从设备、工艺、操作及管理等各方面采取措施,成纱质量不匀、条干不匀及强力不匀等质量指标达到规定要求.     

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.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.