高速织机综框的动态特性分析与设计

综框是开口机构的主要工作部件,其动态性能的好坏会直接影响织机的正常工作。针对不同筘幅的综框,在SolidWorks软件中建立有限元模型,并计算求出综框的各阶模态振型,分析了其动态特性对织机的影响。提出了综框设计时改进其动态特性的措施和方法。     

剑杆织机综框的动态设计与分析

为了解决织机高车速时综框振动加剧,经纱断头率增加,影响织造效率的问题,对铝合金、碳铝复合和碳纤维复合材料综框的动态设计进行具体分析。根据最新国家标准,通过在Pro/E中建立综框系列模型,然后利用有限元分析软件ANSYS Workbench 14.5进行模态分析,获取了相应的固有频率和模态振型。分析、比较3种材料和结构型式综框的动态特性,为综框的固有频率避开工作频率提供了参考,为综框结构的动态设计提供了理论依据;指出:碳铝复合材料的应用是增强铝合金综框刚度的有效方法;碳纤维复合材料综框比铝合金综框具有更好的动态特性;随着织机幅宽的增大,同种材料的综框固有频率在减小,为了适应织机高速应改进综框结构,如增加横梁高度、增加中间支撑、在铝合金综框上填充碳纤维复合材料。     

三维正交织机双向开口机构的设计

为了织出三维正交完全交织的织物,在三维正交织机的开口机构中采用了双向开口即双向综框。介绍双向综框的工作原理,根据传统综框在Pro/E中建立模型,利用ANSYS/Workbench14.5进行模态分析,并选取碳纤维复合材料和铝合金作为综框的材料,得到相应的固有频率和振型。通过分析比较两种材料综框的动态特性,为双向综框的设计提供理论依据。     

基于APDL的综框结构优化设计

为了减小综框在织造过程中的振动和噪声,采用APDL语言建立了综框的参数化有限元模型。通过模态分析计算出了综框的低阶自振频率及振型,在此基础上定义优化执行文件,选用多个结构尺寸作为设计变量,采用零阶方法对其结构进行优化设计,从而有效减轻了综框自重,降低了设计成本。论文确定了一组具有良好动态特性的结构参数,使综框的一阶自振频率增大了10.79 Hz,有效增强了综框的抗振性,以适应更高的织机车速。     

超宽幅织机综框结构设计及振动特性分析

为了解决综框横梁变形、断裂等问题,改进超宽幅织机综框的结构设计,利用Ansys软件中Beam 188梁单元对1000cm幅宽的综框横梁与侧档的连接方式、中间支撑结构、横梁与侧档的截面形状及各构件用材料进行设计与动态分析研究,并分别计算出铝合金无支撑、铝合金有支撑、碳纤维有支撑三种结构的综框在无约束状态下的自由振动与xoy,zoy,zox平面内的自由振动的固有频率值。结果表明:综框增加中间支撑结构后有助于使其具有较好的动态特性;在低阶频率下,综框的主要振型是横梁上下同步或异步振动,横梁的前后同步或异步振动,为宽幅织机在各种工况下稳定运行提供依据;提高综框刚度可减小综框的横向振动,建议综框上、下横梁采用碳纤维复合材料。     

浅谈喷气织机用综和综框的配置

为了合理选用无梭织机用综和综框,并发挥其性能,在分析喷气织机特点的基础上,详细论述了与其配用的综和综框的技术特征及其选用原则,重点阐述了特殊综眼综和碳铝复合综框的适用情况,指出应根据织机型号选择综框生产商,根据幅宽选择综框型号规格,特宽幅选碳铝复合型综框,细号高密织物选特殊综眼综.     

基于材料特性的综框专用件动态设计

综框是重要的纺织机械专用基础件。以230 cm幅宽综框为依据,利用APDL语言设计开发了传统材质综框和复合材料形态综框的建模程序。在此基础上,计算、分析和比较了木质、铁质、铝合金综框与碳纤维复合材料综框的固有频率及振动模式,并通过谐振响应分析获得了X、Y、Z方向的幅频响应曲线,确定了对综框危害较大的谐振频率及响应方向。结果表明:碳纤维复合材料综框的连续安全频率区间(0～87 Hz)明显高于传统综框,具有更优的动力学特性。验证了新型复合材料综框在动力学层面的先进性,为综框专用件的实践选型和织机系统的减振降噪提供了重要参考。     

碳纤维综框

碳纤维具有的高硬度和低重量特性是给予现代综框经受高速织机能力的两个关键因素。超时、加压能导致综框疲劳破损。每分种800次或更高的投纬速度,使综框承受很大的冲击力,即使是轻微的偏移也能导致综片的磨损和破坏。无论是头端开口式钢片还是具有综丝夹钢丝综的设计,为了适应高速织造,钢丝综均向碳纤维综框方向发展,以用于喷气和喷水织机。与常规综框相比,碳纤维综框总重不到其25％,这不仅节约能源,而且也减少织机传动装置和织机其它部件的磨损。例如,一个     

Grob公司的无夹头综框和配有OPTIFIL的综丝

Grob’sRiderfessHealdFrameandHealdswithOPTIFIL新型无夹头综框——easynxeasyfix把无夹头综框的所有优点和夹头系统的处理方法结合起来。easyfix的优良特性如下：——缩短了织机了机时的停车时间，便于提高织机性能；——消除了综丝夹头造成的综丝障碍，可生产出高质量织物，不产生条痕；——减少了次等织物的数量；——一可用于最大抢幅为230cm的任何织机上；．坚固的结构保证了织机在最高运转速度时的可靠性；——省去了夹头综框的高维修成本。配有OPTIFIL综眼的扁钢综丝OPTIFIL为纱线提供了穿过综眼的最佳路径。由于OPTI…     

GA710-230型织机综框损坏问题解决方法的探讨

为了解决GA710-230型织机综框损坏多的问题,分析了综框损坏的原因,采取相应的解决措施并进行了效果对比。指出,车速高低、织物紧度大小、综框材质、回综簧数量多少、穿筘幅宽与织机公称筘幅的差异等是综框损坏的主要原因;通过合理工艺车速、优选综框材质、减少回综簧数量等措施,可大幅减少综框损坏,提高织机效率,减少机配件费用,降低工人劳动强度。     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press