高温法二醋片可纺性表征方法初探

本文利用毛细管流变仪研究了几种二醋片（ＣＡ）丙酮纺丝原液的流变性。分析了粘流活化能（ΔＥη）与可纺性的关系．认为ΔＥη可作ＣＡ－丙酮纺丝原液可纺性的表征参数．ΔＥη越小，可纺性越好．ΔＥη大于８０ＫＪ．ｍｏｌ－１时，可纺性差．     

高温法二醋片丙酮溶液的流变性及可纺性探讨

本文用旋转粘度计法和干法纺丝研究了高温法二醋酸纤维素酯（简称二醋片）丙酮溶液在不同温度、浓度下的流变性，并考察了其可纺性。研究结果表明：高温法二醋片丙酮溶液为切力变稀流体，其粘弹性较低；过滤性和可纺性能良好，纺制烟用二醋纤维主要物理指标为纤度３．１～５．０ｄｔｅｘ，断裂强度０．７４～０．９７ｃＮ／ｄｔｅｘ，伸长率１８～２８×１０－２，基本符合嘴纤半制品要求。     

多检测GPC测试二醋片的分子量及其分布和特性粘度

采用凝胶渗透色谱(GPC)/示差(RI)/小角激光光散射(LALLS)/四毛细管示差粘度(DV)三检测器联用技术对二醋酸纤维素片(二醋片)的重均分子量(Mω)、数均分子量(Mn)、分子量分布(Mω/Mn)和特性粘度(Ⅳ)进行了测试.结果表明:①采用GPC/RI/LALLS/DV技术可以准确地测试二醋片的Mω、Mn、Mω/Mn<和Ⅳ;②以软木浆和短棉绒为原料生产的二醋片的Mω、Mn较高、Mω/Mn较宽;③热解后二醋片的Mω/Mn变宽,Ⅳ降低,并有裂解分子的聚合现象.     

二醋酯纤维和三醋酯纤维性能差异与分析

醋酯纤维是纤维素纤维经乙酰化以后,采用干法纺丝工艺纺制而成的一种化学纤维,根据乙酰化程度可分为二醋酯纤维和三醋酯纤维。文章主要借助傅立叶变换红外光谱仪、X射线衍射仪（XRD）、八篮恒温箱、4种有机溶剂、单纤维强力机、差示扫描量热/热重同步热分析仪,研究二醋酯纤维和三醋酯纤维化学结构、结晶结构、回潮率、耐溶剂稳定性、力学性能以及热稳定性的差异。结果表明,二醋酯纤维的回潮率优于三醋酯纤维,两者耐溶剂稳定性有所差异,化学结构无明显差异,三醋酯纤维的结晶度高于二醋酯纤维,二醋酯纤维的卷曲度高于三醋酯纤维,强度低于三醋酯纤维,两者的热稳定性较为相似。     

静电纺二醋片/UV531防紫外线纳米纤维的性能

为了开发防紫外线纳米纤维纺织品并扩大纳米纤维在纺织材料领域的应用,利用二醋片(CA)和紫外线吸收剂UV531,采用静电纺丝方法制备纯CA纳米纤维和混合的CA/UV531纳米纤维,并利用扫描电镜、紫外分光光度计和紫外线透反射分析仪测试纳米纤维的微观形态、紫外线吸收性能和紫外线防护性能。结果显示:混合的CA/UV531纳米纤维较纯CA纳米纤维的直径略大,且更均匀,说明混合的CA/UV531溶液的可纺性更好;纳米纤维的红外光谱图显示UV531的加入没有影响CA的化学结构;混合CA/UV531纳米纤维的紫外吸收性能和紫外防护性能远远高于纯CA纳米纤维,且随着UV531质量分数的增加,紫外吸收值和紫外线防护系数(UPF)增加,而随着UVA和UVB的透射率降低,紫外防护性能增加。     

静电纺二醋片/三氯生纳米纤维的性能研究

为研究静电纺二醋片(CA)/三氯生纳米纤维的性能,利用静电纺丝方法制备了纯CA纳米纤维和混合CA/三氯生纳米纤维,并利用扫描电子显微镜(SEM)、傅里叶红外光谱仪和万能强力仪测试了纳米纤维的形貌特征、表面化学性能和机械性能。结果表明:三氯生的加入有效地减少了CA/三氯生混合纳米纤维表面的串珠纤维,且纤维直径分布更均匀;混合的CA/三氯生纳米纤维不仅表现出了CA的特征吸收峰,还在900~650 cm~(-1)范围内显示出了三氯生中苯环的弯曲振动峰;三氯生的加入有效增加了CA/三氯生纳米纤维膜的最大伸长,特别是当三氯生含量为1.5%和2.0%时,纳米纤维膜的最大强力和最大伸长都得到了显著增加。     

考陶尔公司拟出售醋酯纤维专利及设备

英国考陶尔公司于今年2月3日派出以公司中央贸易公司董事长卜端为首的高级代表团访华,改变了过去只售醋酯纤维不出售专利技术及设备的方针。现已和中国烟草部门讨论了转让制烟咀的二醋酯丝束的生产技术和设备;和南京化纤厂讨论了转让二醋酯及三醋酯长丝的专利技术及设备。 现将考陶尔公司醋酯长丝生产技术和应用情况简介如下:由于粘胶纤维的三废问题很难解决,而醋酯纤维生产技术近年来已有新的进展,且成本低,世界上已有不少国家开始发展。美国赛拉尼斯和英国考陶尔公司原来是由兄弟俩人分别创建的,目前已成为二个世界最大的醋纤生产厂。目前考陶尔公司每年可生产醋酸酯片能力在5万吨以上。考虑到经济合理性,每条醋酸酯片生产线规模至少为1万吨,而醋酯长丝抽丝生产线每条为5000吨。醋酸酯片除了供抽丝外还可供生产胶片及薄膜。目前,考陶尔公司实际产量约2万吨。生产品种为二醋酯长丝、二醋酯长丝、短纤维和烟咀丝束。其中二醋酯丝和三醋酯丝产量之比约为3∶1。目前考陶尔采用的纺丝机是立式的,干法纺丝,可以同时适用于二醋酯及三醋酯丝的抽丝。纺丝速度约700米/分左右,每台纺丝机生产能力随产品     

烟用二醋酸纤维工业进展

简述了二醋酸纤维的特性、发展历史以及我国烟用二醋酸纤维工业的进展情况;对醋片制造、醋酐制造、醋酸回收、纺丝、丙酮回收等最新制造二醋酸纤维的过程进行了介绍和分析,并对如何进一步发展我国烟用醋纤工业提出了建议。     

ICP-AES法测定二醋酸纤维素片总硫

为监控二醋酸纤维素片(二醋片)产品质量,建立了蒸汽热压加热、ICP-AES测试二醋片总硫的方法,并采用该方法测定了8个二醋片样品中的总硫含量。结果表明:①该方法的检出限为0.051mg/kg,加标回收率为97.2%～100.8%,相对标准偏差2.22%;②二醋片样品的总硫含量为3.2～110.2 mg/kg。     

杨木BCTMP配抄手抄片的性能

在实验室条件下考察了分别用高剪切纤维离解机处理前、后的杨木BCTMP按不同比例与部分阔叶木浆、针叶木浆配抄手抄片物理性能的变化。结果表明,配抄后的浆张松厚度提高,粗糙度降低、不透明度提高,尤其在配抄比例为30％时,配抄BCTMP离解二段纸浆后的浆张不透明度提高达81％;并对配抄前后总体效果进行比较。结果得出,配抄15％的BCTMP离解二段纸浆后,浆张松厚度与空白样相比提高3．4％,表面粗糙度降低3．8％,不透明度提高2．9％,抗张指数增加4.4％,耐破指数几乎不变,但撕裂指数有所下降,这表明高剪切纤维离解机处理后的杨木BCTMP有助于改善纸或纸板的质量。     

纸张三维结构的CLSM表征及纸张特性研究

为采用纤维复配的方法提高蔗渣浆纸张的物理性能,探究了棉浆、马尾松浆、竹浆、桉木浆以及蔗渣浆自身特性和纸张结构。首先检测不同浆种纤维的自身特性,然后提出了一种基于激光扫描共聚焦显微镜(CLSM)的纸张三维结构表征方法,计算纸张的孔隙率用于表征纤维间的相对结合面积,两者结合分析了棉浆、马尾松浆、竹浆、桉木浆与蔗渣浆配抄纸张物理性能的贡献因素。结果表明,CLSM所得到的纸张孔隙率计算值与实验检测值的相对误差小于8%;配抄后纸张物理性能的实验值均大于计算值,具有协同作用,配抄纤维对蔗渣浆纸张物理性能提升的贡献度从大到小依次为:纤维结合能力、纤维自身强度、纤维长度,其中配抄50%马尾松浆的蔗渣浆纸张物理性能提高最大,纸张的抗张指数、耐破指数、撕裂指数分别提高56. 8%、99. 3%、108. 1%。     

COMPARISON OF THE EFFECTS OF ACHROMOBACTER IOPHAGUS AND SPLENIC PULP ON COLLAGEN OF RESTRUCTURED BEEF

Bacterial cultures (BC) of Achromobacter iophagus and bovine splenic pulp (SP) were evaluated for their ability to degrade collagen in a restructured product high in connective tissue. Effects of the BC (6.0% v/w) and SP (3% w/w) on collagen solubility, amino acid composition, thermal stability, and sarcoplasmic and myofibrillar protein extractability were determined. Results yielded increased (P < 0.05) collagen solubility of A. iophagus and splenic pulp treated samples over that of the high collagen (HC) control product. As a result of both treatments, collagen decreased (P< 0.05) in denaturation temperature and enthalpies. Collagen from the BC samples exhibited decreased levels of hydroxyproline, glycine and proline which may be attributable to changes produced in collagen stability as determined by the collagen stability and denaturation temperature measurements.     

EFFECT OF PECTIN CONTENT ON FLOW PROPERTIES OF MANGO PULP CONCENTRATES

The effect of pectin on the flow properties of mango pulp concentrates was studied using a coaxial cylindrical viscometer in the temperature (T) range 303-343°K. The variables were soluble solid content(C) 16-30°Brix, pectin content (C_pec, range 0.0323-0.0349 dry wt fraction) for the shear rate (γ) range 9.0-250 s^-1. Mango pulp concentrates behaved as pseudoplastic fluids in the entire pectin content range with a flow behaviour index of 0.286. A model relating shear stress () with the above variables is presented:     

MINIMAL PROCESSING OF CUSTARD APPLE (ANNONA ATEMOYA) PULP

Fresh custard apple pulp treated with 0.1%– 0.5% ascorbic acid and stored in modified atmosphere generating packages at OC for 4 weeks. The desired creamy color of custard apple pulp was retained during storage and after exposure to ambient conditions for 3h, by the addition of 0.4%– 0.5% ascorbic acid and vacuum packaging in a 65 μm linear low density polyethylene (LLDPE)/nylon/LLDPE 5 layer co-extruded bag. Sensory and microbiological properties of the ascorbic acid-treated custard apple pulp were of acceptable quality throughout the storage period of 4 weeks.     

钛白在CA丙酮溶液中的分散

ＴｉＯ２在ＣＡ丙酮溶液中的分散效果．直接影响到原液的增白、过滤性和可纺性．本文在对比多种分散方式下，选用胶体磨配制ＴｉＯ２浆液，其分散性高，显微镜下观察其粒径较匀，电镜显示其粒径较小，均在５ｕｍ以内，符合烟用二醋纺丝要求．且制法简单，快速。     

EFFECT OF TOMATO DECAY PROPORTION ON ERGOSTEROL LEVEL AND SOME TOMATO PULP PROPERTIES

There is a need to develop a chemical method to determine the amount of decayed tomatoes used to produce tomato products. Tomato pulp samples produced from surface decayed tomatoes as sound, 30, 60 and 100% were tested for pH, brix, titrable acidity, Hunter L, a and b, Howard Mold Count (HMC) and ergosterol values. Tomato pomace for each decay portion was tested for HMC and ergosterol. Ergosterol analysis was carried out by high‐pressure liquid chromatography (HPLC). Decay proportion was linearly correlated with HMC (r = 0.97) and ergosterol (r = 0.96) in pulp samples but not to pH and acidity. Only ergosterol measurement was applicable in tomato pomace and correlated well (r = 0.95) with the decay proportions. In general, the color values of the samples produced from 100% decayed tomatoes were high compared with the others. The measurement of ergosterol has the potential to be used for the quality assessment of tomato products made from Red Top tomatoes.     

棉浆粕制备条件对粘胶生产适用性的影响

本文论述了过低的棉短绒成熟度会引致粘胶生产过程压榨困难和过滤障碍。描述了在蒸球内设置中通管、来用重蒸轻漂、稳定漂白聚合度、以及漂后的除杂疏解等先进的工艺制造棉浆粕，有助于反应性能的提高，改善粘胶的过滤性能。但打浆时过分切断使纤维长度过短，会影响碱纤维素的压榨。采用干毯抄浆、浆粕存放（一段时间）均有助于浆粕水份均匀性的提高。     

THE HEAT OF COMBUSTION OF DRIED CITRUS PULP

The heat of combustion of dried citrus pulp has been found to be 4150 ± 118 cal/g or 7470 ± 212 Btu/lb. Dried citrus pulp has been compared with Bunker “c” fuel as a source of energy and found to be more valuable as a livestock feed.     

竹浆纤维与几种浆粕纤维形态及结构的比较

竹浆可用于制备再生纤维素纤维,而竹浆粕的性质直接影响竹浆粘胶纤维的品质。采用光学显微镜、扫描电子显微镜、傅里叶红外光谱仪和广角X射线衍射仪对几种不同的浆粕原料和竹浆纤维进行分析比较。结果表明:化学脱胶处理后浆粕纤维细胞壁发生了一定的膨胀,且表面显露出原纤化结构,表面没有竹浆纤维光滑;浆粕纤维与竹浆纤维相比,由于去除了较多的非纤维素杂质,某些组分减少;制浆过程显著降低了纤维的结晶度,制浆过程中部分纤维素Ⅰ向纤维素Ⅱ转变。     

EFFECT OF BREAK TEMPERATURE AND HOLDING TIME ON PECTIN AND PECTIC ENZYMES IN TOMATO PULP

SUMMARY –The effect of break temperature and holding time on chemical and physical properties of canned tomato pulp and on the activity of polygalacturonase (PG) and pectin esterase (PE) was investigated. Samples preheated above 200°F were slightly higher in pH value and lower in titratable acidity than those preheated at 160°F and 140°F. The gross viscosity and serum viscosity of the canned tomato pulp increased as break temperature increased. A slight increase in serum viscosity was also observed when holding time was lengthened. The effect of break temperature on serum viscosity was much greater than that of holding time. The total pectin content of the tomato pulp as well as that of the serum increased as the break temperature increased. The same observation holds true for the effect of holding time on the total pectin content of the tomato pulp and tomato serum. This was explained by the inactivation of pectic enzymes at higher break temperature and longer holding periods. The level of PE and PG activity in the frozen tomato pulp decreased as break temperature and holding time increased. No PE activity was detected in samples preheated at 180°F for 15 sec. Samples preheated at 220°F for 15 sec showed no PG activity, while those preheated at 200°F for 15–87 sec still show some PG activity with a retention of about 3.54–5.68%. PG in tomatoes may be inactivated by giving the macerated fruits a hot break temperature higher than 200°F. The critical conditions for inactivation of PE (180°F for 15 sec) and of PG (220°F for 15 sec) found in the course of this investigation are supported by the data obtained on pectin analysis and serum viscosity.