三种阔叶木速生材原料硫酸盐法制浆特性的比较

对生产实际中用于混合蒸煮的三种阔叶木原料木片分别进行了硫酸盐法蒸煮实验,研究了不同原料对用碱量的需要,比较了两种H因子蒸煮后浆料的得率、卡伯值和黑液残碱。实验结果表明了三种原料在制浆特性上的差别,其中两种桉木原料对用碱量的需求有明显的不同,浆料得率存在较大的差异。当用碱量和浆料卡伯值相同时,相思木与桉木相比有较高的浆料得率。     

桉木RDH硫酸盐法制浆性能的研究

研究了桉木RDH（快速置换加热）硫酸盐浆的制浆性能，对桉木RDH硫酸盐法制浆时，用碱量、H－因子、白液的硫化度以及在温黑液预处理段温黑液的活性碱浓度和硫化度等蒸煮条件，对最终制浆结果的影响进行了研究。结果表明：与常规硫酸盐法制浆相比，RDH硫酸盐法制浆时的用碱量相对较高（常规KP法和RDH法的用碱量分别为14％和15％，Na2O计），但RDH纸浆的硬度较低（分别为17．0和11．7）；在纸浆达到相似或较低硬度的情况下，RDH法制浆可以缩短蒸煮时间，或在相同的H－因子下，降低纸浆的卡伯值；在一定的范围内提高白液蒸煮段白液的硫化度，可以降低RDH纸浆的卡伯值或提高纸浆的得率，在温黑液预处理段，温黑液的活性碱浓度和硫化度会对RDH纸浆的最终结果产生较大的影响，对纸浆物理性能的分析结果表明，RDH纸浆在低卡伯值条件下也具有较高的强度性能，但与常规硫酸盐浆相比，RDH纸浆的撕裂强度相对较高耐抗张强度相对较低。     

高卡伯值尾叶桉硫酸盐浆的蒸煮及其性能研究

本文研究了不同条件下尾叶桉硫酸盐法蒸煮的纸浆卡伯值和H因子,纸浆得率、HexA含量和黏度及基于总固形物的残碱含量与卡伯值的关系.结果表明,尾叶桉高卡伯值硫酸盐法蒸煮的特征卡伯值为40,其对应的H因子和较优的活性碱用量分别约为297和19%～20%,此时的细浆得率为52%.当纸浆卡伯值随蒸煮条件的加剧低于该特征值而又大于16时,继续蒸煮不但会导致纸浆得率和黏度的下降以及有效碱消耗的增加,同时纸浆中HexA含量也逐渐增大.     

楸树枝桠材硫酸盐法制浆的研究

对楸树3个无性系的两类径级枝桠材的硫酸盐化学法制浆及造纸性能进行了研究.研究结果表明:粗、细枝桠材硫酸盐法蒸煮最佳用碱量分别为21%和22%(以Na2O计).在此条件下蒸煮,可获得卡伯值为2l、纸浆得率分别为41%和34%的未漂化学浆.在相同的蒸煮工艺条件下,两类径级的楸树枝桠材硫酸盐法制浆性能表现出明显的差异.楸树3个无性系枝桠材硫酸盐法制浆性能差别不十分明显,在相同蒸煮条件下所得纸浆的卡伯值、纸浆得率和筛渣率相近.8401枝桠材硫酸盐浆相对较难漂白,8402和金丝楸硫酸盐浆的可漂性相对较好.     

采用坐标综合评定法优化相思木硫酸盐法制浆工艺

在正交实验的基础上,结合抄纸实验,运用坐标综合评定法确定了相思木硫酸盐法制浆的最佳蒸煮条件。实验结果表明,在用碱量15%(以Na₂O计)、硫化度30%、液比1∶4、蒸煮最高温度165℃、升温时间60 min、保温时间120 min的条件下进行硫酸盐法蒸煮,所得纸浆得率52.25%,卡伯值17.9,黏度987.3 mL/g,裂断长9.32 km,抗张指数93.6 N·m/g,撕裂指数10.0 mN·m2/g,耐破指数5.34 kPa·m²/g。     

红麻全秆硫酸盐法制浆工艺的优化

介绍红麻全秆硫酸盐法间歇蒸煮的实验室研究及中试生产试验。结果表明,优化的红麻全秆硫酸盐法制浆工艺条件为:用碱量18%(Na2O计),硫化度25%,温度165℃,保温时间2h。生产试验结果与实验室结果相吻合,红麻全秆可以在常规的草类制浆线上正常生产。生产纸浆的粗浆得率为45%,卡伯值为22。此外,蒸煮黑液的碱回收是可行的。     

最新国外文献资料馆藏题录

一碱法制浆—蒸煮器的操作和控制 1.米德·金斯普特(The Mead Kingsport)苏打-蒽醌制浆厂的蒸煮器运行条件和纸浆质量 2.硫酸盐制浆工艺的一种新的控制方法 3.热纯化技术减少卡米尔蒸煮器腐蚀速率 4.间歇式蒸煮过程中合适的卡伯值控制 5.在硫酸盐间歇蒸煮过程中在线分析蒸煮液测定纸浆得率和卡伯值     

以RDH法制备桦木硫酸盐浆蒸煮的研究

研究了桦木以RDH硫酸盐法蒸煮,结果表明：可在较低用碱量及低H－因子的条件下,制备低卡伯值,高撕裂度的桦木硫酸盐浆,但纸浆得率偏低,其它强度性能也稍低。     

制浆工艺对高得率KP浆羧基含量的影响

绿液预处理和硫酸盐蒸煮工艺参数影响纸浆的羧基含量.随着绿液用量的增大、预处理温度的升高、时间的延长,羧基含量开始增加,而后减少;当预处理绿液用量为30%、120℃、处理时间30～40min时,羧基含量达到最大值.用碱量是对羧基含量影响最大的参数,羧基含量随KP蒸煮段用碱量的增大明显下降;H-因子为1200时,羧基含量较高.随着卡伯值和得率的降低,羧基含量减少.制浆方法也会影响羧基含量,不同制浆方法所得的纸浆在得率或卡伯值相同的情况下,羧基含量有所不同.     

硫酸盐法蒸煮白液中加甲醇的好处

不少研究成果已表明，甲醇加入普通硫酸盐法中可以加速脱木素作用和保护碳水化合物在蒸煮过程中不受或少受降解。试验研究所用原料为白桦木片，厚度2一6mm，液比4:1，蒸煮后木片在5％浓度分离纤维和纸浆用热水洗后，用标准方法测定机械强度。蒸煮用活性碱Na_2O17.5％，蒸煮温度165℃。测得的纸浆卡伯值、得率和粘度列于表1。从表1所列结果，计算了三个参数的回归方程式：卡伯值：在规定H一因子=800时，当硫化度和甲醇浓度增加时，由图1可见纸浆卡伯值降低，而较低的卡伯值表示在有甲醇时木素易于溶出。H一因子=800活性碱=17.5%得率：得率=…     

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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.