技术问答

问:双绉“糙纬”是怎样产生的?如何克服? 答:在双绉的成品检验中,经常因为绸面“糙纬”(俗称“蚱蜢纡”)造成质量扣分,甚至降等。由于其分布缺乏规律,加之绉线加工均为高速卷、退过程,生产中往往难于把握“糙纬”产生瞬间的部位和原因。但经仔细分析和拆绸发现,双绉“糙纬”主要是绉线扭缩后织入绸面所致。又因扭缩程度不同呈0.5～1cm大小不等的形态。产生的原因不外乎有以下几种:     

影响12107双绉缩水率的原因分析

降低真丝双绉的缩水率,无论是对消费者的服用要求,还是对在国际市场上提高竞销能力,都是十分必要的。1981年7月,江苏省丝绸公司对全省生产12107双绉的十家丝织厂、四家印染厂的产品进行抽验,12107双绉的练整平均缩率为5.64%,平均经向缩水率为10.58%,纬向缩水率为3.49%。各厂由于生产条件不同,其产品的缩水率也不本文以12107双绉为例,从生丝应力应变特性出发,通过对织造、染整的十道主要     

提高染色双绉质量技术要点

1981年以来,由于对外贸易的需要,复制品由我省自行染色,通过学习上海、江苏等地先进经验,进行了多次全省性的双绉染色技术经验交流会以及实物评比,加强了织、染厂之间的密切协作,使我省染色双绉质量不断提高。1981年1～8月全省双绉染色成品一等品率达到93.80%,比去年同期提高了3.45%。为了进一步稳定和提高染色双绉的质量,在最近召开的全省实物评比经验交流会上,经过各印染厂讨论,初步制订了我省双绉染色的技术要点,由于各厂的设备不一,条件不一,无法完全统一。今提出以下各点供参考。一、选坯织厂对生坯先行挑选,根据档     

真丝双绉织档与练整缩率的关系

通过对12102真丝双绉的织档分析及不同练整缩率对织档影响的对比试验,探索真丝双绉的织档与练整缩率的关系,确定合理的练整缩率,指出克服织档须从织造过程找原因。     

粘胶人丝双绉织物绉效应的探讨

对不同规格的粘胶人丝双绉类织物的坯绸和成品进行了定量测试，比较不同织物的绉效应和风格，并分析了经密、纬密、捻度等对绉效应的影响，探讨了产品生产中的合理技术参数和织造工艺。     

真丝绉缎织物的设计与开发

通过对真丝绉缎类品种157个规格的密度、线密度、紧度及缩率等参数的分析,利用线性回归以方程、图表等研究织物规格的取值范围、相互关系,探索该类织物设计的一般规律,对绉缎织物的设计具有一定的指导价值。     

提高真丝练白双绉的实物质量

双绉练白质量好坏,直接影响产品最终质量。为此,提高真丝绸质量,使之畅销国际市场,减少真丝绸织造疵点,提高精练后的白度、光泽、手感、渗透等效果,是十分重要的。     

双绉类织物舒适性能影响因素的分析

运用多元线性回归分析方法，分析了织物规格对双绉类织物舒适性能的影响，并讨论了各性能的影响因素，为真丝双绉、涤纶双绉及粘胶双绉的合理设计，提供了科学的参考依据。     

真丝染色双绉灰伤病疵的防止方法

为了满足外贸需要,我厂染色双绉的出口量也日俱增多。由于染包双绉易产生“灰伤”,曾影响了产品质量和外贸履约率的完成。针对“灰伤”病疵,我们进行了各种工艺试验与分析,探讨了“灰伤”产生的原因,提出了防止方法。从而使染色双绉的正品率由70％提高到94％左右,得到了客户的好评。     

论涤纶仿真丝绉类织物的绉效应

涤纶仿真丝绉类织物要获得良好的绉效应,应在织物设计和工艺设定中,注意选用较细的、抗扭牲好的原料,提高捻度,定形不可过足,合理选择经纬密度、幅缩率和织造张力,再配以合理的后处理工艺,从而使仿真丝绉类织物的绉效应接近同类真丝织物。     

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