聚丙烯纺粘/针刺型模板布成型工艺与性能

在聚丙烯针刺毡表面进行纺粘工艺,并进行热合层压处理,获得具有一定孔径和透排水性能的透水模板布。通过正交试验获取制备纺粘/针刺透水模板布的最佳工艺,讨论了热压温度和纺粘克重对透水模板布相关性能的影响。结果表明：热压温度为171℃,热压时间为4s,热压压强为1.5MPa时,聚丙烯纺粘/针刺型透水模板布的导水性能达到最优,在相同的热压时间与热压压强下,模板布内部纤维的密集程度及表层凝结性能随热压温度的变化影响其最终的使用效果。     

紫外线辐射对聚丙烯非对称固液分离膜结构与性能的影响

对聚丙烯非对称固液分离膜进行紫外线辐射处理,得到不同温度下分离膜的老化规律,通过对分离膜的形态结构、物理机械性能和浸润性能进行研究,结果表明：在45 ℃处理1 d后,聚丙烯分离膜表面出现C=O伸缩振动峰,说明膜表面开始被氧化;在45 ℃和60 ℃分别处理6 d和4 d后,分离膜的断裂强度保持率分别为2.28%和5.81%,已失去使用价值,且膜表面的亲水性消失,导水性明显下降。     

聚丙烯膜裂纤维生产设备及工艺的改进

介绍了对某纤维厂聚丙烯编织袋扁丝生产线的技术改造情况;探讨了生产条件对扁丝性能的影响;指出熔膜挤出后的冷却情况对扁丝的成丝条数、强度、拉伸性和均匀性有着非常重要的影响。     

用低熔点共聚酰胺非织造纤网作粘合剂的粘合工艺研究

主要介绍了采用低熔点共聚酰胺非织造纤网为热熔胶,通过压烫实验探索出合适的粘合工艺。用以指导该热熔胶粘合的生产实践。     

平板式固液分离设备的设计

本文设计一种新型的平板式固液分离设备,解决目前固液分离不干净、重量重和成本高的问题。同时在设计过程中,不断改善制造工艺,在保证性能的前提下,化繁为简,在制造加工时,节约人工成本和工时,为产品价格的核心竞争力提供有力的保证,缩短产品的加工周期。     

热轧工艺对针刺清洁抹布基布性能的影响

研究了热轧工艺对针刺清洁抹布基布性能的影响。经热轧定型后的针刺基布,其柔软度、透气性和吸水率均有一定程度的下降。结果表明:混合比为70:30的粘胶纤维/涤纶针刺基布在温度180益、时间30s和60s的条件下进行热轧处理,其性能指标能够达到清洁抹布的要求。     

无花果多糖分离纯化工艺及抗氧化性能研究

探讨无花果多糖分离纯化工艺及抗氧化性能,以无花果为试材,通过选用不同树脂去除无花果多糖中的色素,结果表明使用AB-8树脂效果最好;利用3％三氯乙酸法去除蛋白质,选用0.03 mg/mL的NaCl溶液洗脱纯化,使用AB-8柱层析色谱图在管数为10～20,30～40时出现脱峰,分离纯化完成.通过测定清除超氧阴离子自由基、羟...     

超细毛洗毛工艺的实践和探索

叙述了用低温碱性洗毛工艺洗涤12μm超细毛的工艺条件,该工艺也可推荐用于64支、66支、70支毛的洗涤。文章以五槽洗毛机为实例,介绍了工艺计算过程,确定了洗涤时间、温度、pH值和洗涤剂用量。     

生物质固体成型燃料的发展、工艺及性能分析

针对我国丰富的农作物秸秆和林业剩余物资源,采用挤压成型工艺将其制备成生物质固体成型燃料(简称木煤),并对成品燃料进行理化分析及燃烧性能分析,结果表明1t木煤可以替代1t二类烟煤.生物质固体成型燃料是一种优质的生物质燃料,清洁环保、可再生、燃烧性能好,有效的开发和利用对我国能源产业结构的转变有重要意义.     

热轧复合工艺对PTFE膜和PET纺粘非织造布复合材料性能的影响

介绍了采用正交实验分析法对PTFE膜/PET纺粘非织造布热轧复合材料的剥离强力的研究,选择热轧温度、热轧压强和热轧时间三个因素、三个水平进行相关实验,说明了影响PTFE膜/PET非织造布热轧复合材料剥离强力的主要因素.     

低熔点聚酰胺的制备与性能

为改善聚酰胺加工工艺,以十二碳二元酸、癸二胺、癸二酸、己二胺、己内酰胺为原料,通过直接熔融缩聚法制得不同二元胺配比的低熔点聚酰胺。用傅立叶变换红外光谱（FT-IR）、差示扫描量热（DSC）、热重分析（TGA）等对制得的样品进行了表征。FT-IR测试表明,低熔点聚酰胺的谱图呈现典型的聚酰胺特征峰;DSC测试表明,随着两种二元胺比例接近1:1,聚合物熔点和结晶能力明显下降;TGA测试表明,随二元胺中癸二胺比例的增加,低熔点聚酰胺的热稳定性提高;沸水萃取实验测试表明,合成的低熔点聚酰胺中单体及低聚物含量均小于0.63%,无需萃取,可以直接满足后加工的要求。     

提高结晶山梨醇熔点的工艺探讨

山梨醇是一种用途广泛的化工、食品、医药原料,结晶山梨醇应用更广,但必须掌握好其结晶的条件才能制备出熔点高的结晶山梨醇。本文对山梨醇结晶的工艺条件进行了深入研究,通过对结晶温度、结晶时间、晶种用量及晶种粒度进行了单因素对比试验,并用三因素三水平正交试验表安排了正交试验,优化结晶工艺条件。根据正交试验结果的极差分析及方差分析,对三因素的显著性作出了判断,确定了影响结晶山梨醇熔点的显著因素为结晶温度,也找出了原来产品熔点低的主要原因,对原装置上的结晶温度控制系统进行了改造,并对操作人员进行了培训,按优化的条件生产后,结晶山梨醇的熔点稳定达到101℃以上,达到进口样品的水平,其优化的条件为:结晶温度:70℃,结晶时间:40min,晶种用量:10%。     

Improvement of gel strength and melting point of fish gelatin by addition of coenhancers using response surface methodology

Abstract: Fish gelatin is a potential alternative to mammalian gelatin. However, poor gel strength and low melting point limit its applications. The study was aimed at improving these properties by adding coenhancers in the range obtained from response surface methodology (RSM) by using Box–Behnken design. Three different coenhancers, MgSO₄, sucrose, and transglutaminase were used as the independent variables for improving the gel strength and melting point of gelatin extracted from Tiger‐toothed croaker (Otolithes ruber). Addition of coenhancers at different combinations resulted gel strength and melting point in the range of 150.5 to 240.5 g and 19.5 to 22.5 °C, respectively. The optimal concentrations of coenhancers for predicted maximum gel strength (242.8 g) obtained by RSM were 0.23 M MgSO₄, 12.60% sucrose (w/v), and 5.92 mg/g transglutaminase and for predicted maximum melting point (22.57 °C), the values were 0.24M MgSO₄, 10.44% sucrose (w/v), and 5.72 mg/g transglutaminase. By addition of coenhancers at these optimal concentrations in verification experiments, the gel strength and melting point were improved from 170 to 240.89 g and 20.3 to 22.7 °C, respectively. These experimental values agreed well with the predicted values demonstrating the fitness of the models. Results from the present study clearly revealed that the addition of coenhancers at a particular combination can improve the gel strength and melting point of fish gelatin to enhance its range of applications. Practical Application: There is a growing interest in the use of fish gelatin as an alternative to mammalian gelatin. However, poor gel strength and low melting point of fish gelatin have limited its commercial applications. The gel strength and melting point of fish gelatin can be increased by incorporation of coenhancers such as magnesium sulphate, sucrose, and transglutaminase. Results of this work help to produce the fish gelatin suitable for wide range of applications in the food industry.     

Effects of chemical interesterification on solid fat content and slip melting point of fat/oil blends

Fat/oil blends, formulated by mixing fully hydrogenated palm oil stearin or palm oil stearin with vegetable oils (canola oil and cottonseed oil) in different ratios from 30:70 to 70:30 (w/w %), were subjected to chemical interesterification reactions on a laboratory scale. Fatty acid (FA) composition, iodine value, slip melting point (SMP) and solid fat content (SFC) of the starting blends were analysed and compared with those of the interesterified blends. SMPs of interesterified blends were decreased compared to starting blends because of extensive rearrangement of FAs among triacylglycerols. These changes in SMP were reflected in the SFCs of the blends after the interesterification. SFCs of the interesterified blends also decreased with respect to the starting blends, and the interesterified products were softer than starting blends. These interesterified blends can be used as an alternative to partial hydrogenation to produce a plastic fat phase that is suitable for the manufacture of margarines, shortenings and confectionary fats.     

可用于熔喷生产的低熔点共聚酰胺黏度与温度关系的研究

用自制的高温落球黏度计测试两种低熔点共聚酰胺的零切黏度,获得零切黏度与熔体温度的关系,为相应的理论研究打下了基础。从零切黏度的测试结果求出两种原料的黏流活化能。所测试的两种原料中原料2的黏流活化能较小,在同样温降范围内其黏度降也较小,即不容易发生热降解,因此更适合于熔喷生产。     

新型毛纱热熔浆料的开发

介绍了毛纱上浆对热熔浆料的基本要求,研制了一种适合毛纱上浆的热熔浆料,并对上浆毛纱的各项性能指标进行了测试和比较。     

油脂熔点对植脂鲜奶油质量性能的影响及其机理的研究

利用质构分析仪分析泡沫硬度和内部质构,油溶性色素法(油红-O)测定脂肪球部分聚结率,研究油脂种类对植脂鲜奶油质量性能的影响.结果表明,不同种类油脂制备的植脂鲜奶油的质量性能有较大差异,油脂种类对质量性能的影响与其熔点有关.随油脂熔点不同,在搅打过程中发生脂肪球部分聚结的程度也不同,从而影响最终的泡沫结构.搅打5 min后,熔点为47～53℃的部分氢化植物油HP-51的部分聚结率大于70%,天然奶油的部分聚结率小于10%,大豆油和极度氢化油不发生部分聚结,均不能形成稳定的泡沫结构.熔点为36～41℃的部分氢化植物油制备的植脂鲜奶油,部分聚结率为65%,膨胀率为4.0,获得稳定的泡沫结构.     

抗氧化剂与降凝剂对生物柴油性能的复合影响研究

以小桐子生物柴油为原料,研究了市场上常见的6种抗氧化剂和6种降凝剂复合作用对油样诱导期、凝点、运动黏度和热值的影响规律。结果表明:不同种类降凝剂对抗氧化剂的抗氧化效果影响较大,但影响规律与抗氧化剂种类无关,影响范围在5%以内;降凝剂与抗氧化剂对生物柴油凝点和运动黏度的复合影响较大,主要影响因素是抗氧化剂油溶性,油溶性好的抗氧化剂能够促进生物柴油凝点降低,但相应会增大运动黏度;降凝剂与抗氧化剂对生物柴油热值复合影响较小,影响因素主要是添加剂本身化学成分的热值高低;添加降凝剂可以提高生物柴油热值。     

Effect of crystal promoters on viscosity and melting characteristics of compound chocolate

The effects of the addition of crystal promoting additives to compound chocolate viscosity and melting characteristics were evaluated in this study. Three types of crystal promoters, namely CP1, CP2, and CP3, were added at varying concentrations (0.25, 0.5, 0.75, and 1.0%). The compound chocolate with no added crystal promoters served as a control. Increase in viscosity with increasing additive concentration was observed among all samples regardless of additive type. Addition of CP1 resulted in significant changes in dimensions and shape deformation after incubation at 40°C for 24 h except at 0.25% concentration. Samples with CP2 and CP3 were fairly stable at 40°C with only CP3 0.25% melting. Crystal promoter type influenced the melting properties of the samples, as determined through differential scanning calorimetry, particularly in terms of T_index and ΔH_M. The ΔH_M of all the samples decreased, while the addition of CP1 decreased T_index values, and adding CP2 and CP3 increased the T_index. Additive type had limited effects on T_peak, T_onset, and T_endset. Results suggest that crystal promoters added to compound chocolate affect their viscosity and thermal behavior.     

Diverse metabolism of cell wall components of melting and non‐melting peach genotypes during ripening after harvest or cold storage

The mode of change in a range of physiological, physicochemical and biochemical parameters during fruit ripening between distinct peach genotypes (Prunus persica L. Batsch) after cold storage for up to 4 weeks was determined. The nectarine cultivar ‘Caldesi 2000’ was selected as a genotype with melting flesh (MF) characteristic (fruits characterized by extensive flesh softening during ripening) and the cultivar ‘Andross’ as a genotype with non‐melting flesh (NMF) characteristic (fruits characterized by limited flesh softening during ripening). Flesh firmness, ethylene production, physicochemical and biochemical properties of the cell wall were determined and significant differences between the fruits of the two genotypes were recorded. Fruits of the NMF genotype were characterized by higher tissue retention and ethylene production during their ripening, higher content of uronic acids, as well as higher capacity for calcium binding in the water‐insoluble pectin fraction compared with fruits of the MF genotype. Additionally, the ripening of MF‐type fruits was characterized by higher losses of neutral sugars, especially those of arabinose and galactose than the NMF‐type fruits and these losses were more intense after extended cold storage periods. In fruits of the NMF genotype the decreased activity of pectin methyl esterase (PME) combined with higher levels of calcium in the water‐insoluble pectin fraction possibly provided less substrate for polygalacturonase (exo‐, endo‐PG) activity and less solubility of cell wall pectin compared with fruits of the MF genotype. Overall, the data indicate the existence of a wide range of diverse metabolic pathways during fruit ripening of fresh fruits with MF and NMF characteristics. Copyright © 2005 Society of Chemical Industry