慈竹溶解浆预水解助剂的应用

通过单因素实验方法,研究预水解助剂在慈竹溶解浆中的应用以及溶解浆制备的适宜工艺条件。结果表明,预水解段优化工艺条件为：预水解助剂用量0.5%（对绝干竹片）,保温时间60 min;预水解结束后进行碱液中和,再进行硫酸盐法蒸煮,蒸煮优化工艺条件为：用碱量18%（Na₂O计）,保温时间90 min;在此工艺条件下得到本色竹材溶解浆性能指标为：白度37.3%,黏度992 mL/g,得率29.5%,卡伯值8.0,碱溶解度S182.03%、S103.38%、S10-S181.35%;对本色竹材溶解浆进行D0ED1A四段漂白,与未加预水解助剂相比,预水解助剂用量0.5%时可制得α-纤维素含量96.2%、白度86.3%、低聚类分子数量、灰分及铁含量均低于未加预水解助剂时制得的浆料,且聚合度达1097,可满足多种溶解浆产品的生产要求。     

楠竹溶解浆的制备

本文对楠竹制溶解浆的工艺进行了优化,优化工艺是:在170℃下预水解120min;然后采用硫酸盐法蒸煮,蒸煮条件为:用碱量14%(Na2O计),硫化度20.5%,保温温度165℃,保温时间90min;接着采用ECF漂白,制得了α-纤维素含量为98.74%、聚合度为1062、粘度为18.11mPa*s、白度为88.96%ISO、灰分含量为0.06%、尘埃度为3mm2/500g的高质量溶解浆.     

溶解浆粕制备过程中降低聚戊糖含量的方法

在溶解浆粕的制备过程中,能否大量去除纸浆中的半纤维素从而提高其α-纤维素的比例是关键。研究了由木材原料通过蒸煮制备溶解浆粕过程以及由竹浆直接制备溶解浆过程中降低其半纤维素含量的方法。在由木片为原料通过蒸煮制备溶解浆的实验方案中,主要研究了预水解硫酸盐法中预水解工艺对纸浆中半纤维素含量的影响,认为预水解保温2h能较为有效地降低蒸煮所得纸浆的半纤维素含量;在由竹浆原料直接制备溶解浆的实验方案中,重点研究了酸处理工艺以及碱处理工艺对去除竹浆中的半纤维素以及降解纤维素聚合度方面的影响,并得出酸处理与碱处理相结合的方法能够最大限度地去除半纤维素同时保护纤维素聚合度。     

醋化级芦苇溶解浆的制备及其性能

为探索使用可再生的芦苇资源制备醋化级溶解浆的可行性,以湖南洞庭湖区的南荻为原料,采用水预水解-硫酸盐法蒸煮-D₀E_pD₁(ClO₂漂白脱木素段-H₂O₂漂白段-ClO₂漂白增加白度段)3段漂白工艺制备了南荻浆粕,并对其甲种纤维素含量、白度、聚合度、多戊糖含量、灰分含量和铁含量,以及表观形貌、化学结构和晶体结构等进行测试与分析。结果表明：蒸煮后南荻的粗浆得率为46.31%,3段漂白工艺使南荻浆粕的主要性能指标得到明显改善,其甲种纤维素含量提高了1.24%达到97.70%,白度提高1倍达到91.42%,特性黏度降低38.01%,使南荻浆粕的平均聚合度达到1 413;制浆过程中高温、NaOH、Na₂S、ClO₂和H₂O₂的共同作用使南荻中的木质素、半纤维素和灰分得到有效去除。本文工艺制备的南荻浆粕的性能达到了醋化级溶解浆的基本要求,为下一步制备醋酯纤维素...     

混合竹材制备溶解浆的工艺试验

以混合竹片(慈竹、黄竹、西凤竹=1:1:1)为原料,对其化学成分进行分析,并采用预水解硫酸盐法蒸煮、OD0EPD1多段漂白工艺制备混合竹片溶解浆。试验发现:混合竹片的综纤维素74.52%、木素25.08%、戊糖20.67%、灰分2.25%,适用于溶解浆的制备原料;采用预水解硫酸盐法蒸煮、OD0EPD1工艺漂白能够生产出质量合格的竹纤维溶解浆。     

不同树龄竹柳特性分析及其溶解浆纺丝工艺探究

通过对不同树龄竹柳进行化学组分和纤维质量的分析,确定用于制浆的竹柳树龄。采用预水解、硫酸盐法蒸煮、ECF漂白等处理,研究了不同蒸煮条件对竹柳成浆性能的影响。通过对竹柳溶解浆成丝品质的检测,评价了竹柳溶解浆的纺丝性能。结果表明,3年生竹柳的应用价值较高,以其制备的溶解浆,预水解后多戊糖脱除率达56.31%,与桉木相当。经过总用碱量（Na₂O计）19%、硫化度18%的硫酸盐蒸煮后,竹柳成浆特性黏度605 mL/g,聚合度861。经D₀E_pD₁P四段ECF漂白后,竹柳溶解浆关键性能指标均满足行业标准中优等品的要求。竹柳溶解浆与常规商品阔叶木溶解浆无明显差异,纺丝后的黏胶过滤性能较好,丝束性能指标满足国家标准中合格品要求。     

Lyocell纤维纺丝用溶解浆的制备及性能表征

本研究以针叶木浆为原料,通过冷碱抽提、过氧化氢降聚、乙酸酸化等工艺制备可达到Lyocell纤维纺丝用标准的溶解浆.结果 表明,采用针叶木浆制备的溶解浆达到Lyocell纤维纺丝用标准;溶解浆中α-纤维素含量达到96.12％,纤维素聚合度降至653,灰分含量0.07％,铁离子含量小于4 mg/kg;溶解浆在N-甲基吗啉-...     

竹子生产溶解浆

评价了以商品竹片为原料生产溶解浆的可行性。首先将竹片进行自水解(AH),烧碱/蒽醌法蒸煮,并用O-CCE-D-(EP)-D-P流程进行高白度漂白(CCE为冷碱抽提段)。虽然竹片的化学组成(木素22.4%,聚木糖19.5%,纤维素49.3%,总抽提物16.8%,灰分1.5%)看似不利于生产,但采用上述工艺还是生产出了高质量的溶解浆。生产的溶解浆具有较高的白度(92.4%)和-纤维素含量(94.9%)。竹浆的半纤维素、抽出物和灰分含量对于生产黏胶人造丝用溶解浆均在可接受范围内。因此,竹子作为溶解浆生产的原材料是可行的。     

优化ECF漂白工艺制备竹子溶解浆

采用D_0ED_1ED_2工艺对未漂竹浆进行漂白。优化二氧化氯漂白pH、时间、温度、用量等因素,确定D_0ED_1ED_2最佳工艺条件,从而制备溶解浆。实验结果表明:采用优化后的D_0ED_1ED_2漂白工艺可以制得α-纤维素含量97.37%、白度87.26%ISO、聚合度1457、灰分含量0.06%的溶解浆。     

木聚糖酶处理对麦草溶解浆制备性能的影响

对自制乙醇法漂白麦草浆用木聚糖酶处理,对处理后浆粕的α-纤维素含量、聚戊糖含量、灰分、平均聚合度及白度进行测定,结果表明,经过木聚糖酶（1.0IU/g）处理后浆粕的α-纤维素含量能够满足短纤溶解级浆粕的要求,其灰分含量没有明显变化,平均聚合度、白度等指标有所提高。NaOH（质量分数5%）协同处理,浆料中的灰分含量下降明显。实验表明,采用自制乙醇法漂白麦草浆的酶处理和碱处理工艺,可生产出合格的溶解浆粕。     

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