假捻集聚纺纱线的特征分析

探讨假捻集聚纺纱线的性能特点.测试了不同捻系数假捻集聚纱线的各项主要性能,并与同捻度的传统环锭纱线进行了对比试验分析.结果表明:捻系数为280的假捻集聚纱线.其条干CV值均比同捻系数的传统环锭纱差,而纱线的毛羽指数、断裂强度和断裂伸长率也只有在假捻器转速比适当的条伴下才好于传统环锭纱.而当捻系数为360时,假捻集聚纱线的条干CV值和断裂强度只有在假捻器转速比较低时才好于传统环锭纱,而毛羽指数和断裂伸长率则可在较大的假捻器转速比范围内优于环锭纱.     

低捻纱的纺制及成纱性能研究

为了增加对低捻纱工艺和性能的认识,明确不同纺纱方式低捻纱性能的区别及假捻器对不同纺纱方式低捻纱性能的影响,通过纺制不同纺纱方式低捻纱,并对条干均匀度、断裂强力和3 mm毛羽数等性能进行测试并分析。结果表明:4种纺纱方式低捻纱中,集聚纺低捻纱条干均匀度最好;赛络集聚纺低捻纱断裂强力最高,3 mm毛羽数最少;假捻器可明显提高集聚纺低捻纱的强力,降低普通环锭纺和集聚纺低捻纱的毛羽;JC 11.66 tex赛络集聚纺低捻纱的最低捻系数可达137。认为:纺纱方式和假捻器对低捻纱性能有较明显的影响。     

假捻集聚纺纱外观及结构分析

探讨假捻集聚纺纱工艺及其成纱结构特点。使用显微镜观察并分析了假捻集聚纱和传统环锭纱的外观形态结构,并使用填充密度来表征纤维在成纱横截面内的分布情况。试验结果表明:假捻集聚纱的外观均匀度和表面毛羽状况要好于具有相同捻系数的传统环锭纱。纤维在纱横截面内的填充密度分布规律可以用一个三次方程拟合。与同捻度的传统环锭纱相比,假捻集聚纱在靠近纱芯的内层填充密度较大,外层填充密度略小。     

网格圈负压式集聚纺集聚区须条半自由端加捻机制

网格圈负压式集聚纺纱实践表明,在相同工艺条件下,纺制相同线密度的纱线,集聚纱捻度比环锭纱捻度高5％左右.为揭示此现象的形成机制,采用高速摄影技术,对直线形集聚斜槽集聚区须条的集聚情况进行拍摄,发现存在类似卷捻的现象.通过纺纱实验,对采用相同工艺纺制的相同线密度的集聚纱和环锭纱捻度进行对比,结果表明集聚区须条的附加捻度是...     

假捻器在环锭纺上的应用

为了解决传统环锭单纱残余扭矩的问题,提出在现有环锭细纱机导纱钩与前罗拉之间加装新型假捻器的设想,设计的假捻纺纱技术既能提高环锭纺的产能,又能减少断头;改进后的环锭纺纱机可纺出低捻、高强、残余扭矩小、手感独特(柔、顺)、织物歪斜小等特性的新型纱线;说明该假捻纺纱技术改变了传统的纺纱成纱形式,在技术改造、纱线成纱指标、后期...     

太空耐温纱纺纱工艺

采用环锭包芯纺纱技术纺制芳纶1313与涤纶耐温包芯纱,对其工艺参数进行了优化。结果表明在相同原料条件下,用环锭包芯纺纺制48tex耐温纱时,捻系数、长丝张力等工艺参数对包芯耐温纱成纱质量有较大影响;最优工艺参数为捻系数420,长丝张力14.7cN。     

旋流器对环锭纺纱线性能的影响

在传统环锭细纱机的前罗拉与导纱钩之间安装旋流器进行纺纱,能够较好地改善环锭纺纱线的性能。通过正交试验的方法,考察了气压、锭速、捻系数和旋流器到前钳口的距离对纱线质量的影响,得出优化的参数组合。结果表明：气压为0.25 MPa、旋流器到前钳口的距离为6.5 cm、捻系数为330、锭速为9000 r/min时,所纺纱线质量最好;与传统环锭纺纱线相比,这种纺纱方法所纺得的纱线毛羽减少量达到97％,断裂强度提高了9%,条干不匀降低6%,为研究提高纺纱性能的新型纺纱方法提供参考。     

不同纺纱方法的成纱机理及纱线耐磨性能研究

探讨传统环锭纺、集聚纺、赛络纺、集聚赛络纺、喷气涡流纺的成纱机理以及纱线耐磨性能。用这5种方法纺100%新疆长绒棉精梳11.6tex纱。对比测试了纱线的条干、毛羽、强力和耐磨性。结果表明:集聚赛络纱的各项质量指标和耐磨性均优于其他纺纱。虽然喷气涡流纱的强力和条干不如传统环锭纱,但是耐磨性和毛羽比传统环锭纱好。认为:在集聚纺、赛络纺、集聚赛络纺这样一些环锭纺纱新技术的纺纱过程中,集聚和并合作用都能提高纱线的耐磨性,集聚程度对纱线的耐磨性影响较大,并合作用相对较小。两种同时采用时,改善耐磨性的效果最好。同原料同号棉纱,其耐磨性与条干、强力、毛羽等性能呈现一定的相关关系,条干好、强力高、毛羽少的纱线耐磨性较好。     

环锭精纺回转钢领加速问题的研究

一、引言环锭精纺仍然是纺制短纤维纱的一种主要方法。新的纺纱技术,诸如气流纺、雷普科自捻纺、特维洛粘结纺、搓捻纺或喷气纺,虽然具有高产和高度自动化的优点,但这些方法所纺纱的用途,与环锭纱相比,或多或少受到限制。环锭纱的结构和性质依然经常作为评价     

假捻装置作用于不同纱支及纺纱方式的效果分析

由于假捻纺纱技术作用在普通环锭细纱机上可生产低捻高强纱,为了了解假捻装置应用于不同纱支及纺纱方式的效果,文章采用一种自主研发的假捻装置对纯棉纱进行试纺。通过环锭和赛络两种纺纱方式对不同细度(16S、21S、40S)纱线的不同捻度分别进行有无假捻装置情况下的纺纱,并对强伸性及毛羽性能进行测试,旨在得到假捻装置作用效果明显的纱支、捻度和纺纱方式。实验结果表明:假捻装置对低捻纱的作用效果高于高捻纱;对环锭纺纱的作用效果优于赛络纺;对高支纱效果优于低支纱。     

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.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.