无机粉体改性聚丙烯纺粘法非织造布研究

介绍了无机粉体改性聚丙烯纺粘法非织造布的经济性、功能性、环境友好性,以及无机粉体填充改性聚丙烯复合材料的改性方法和影响因素[1]。详细阐述了无机粉体改性聚丙烯纺粘法非织造布研究的相关内容。     

无机粉体改性聚丙烯纺粘非织造布的力学性能

 将无机粉体碳酸钙功能母料和聚丙烯(PP)切片按一定比例混合后,在1600mm窄幅式纺粘非织造实验机上制得PP纺粘非织造布。研究了无机粉体碳酸钙的含量和纤维直径、纤维结构以及改性PP纺粘非织造布物理机械性能之间的关系。研究表明：当无机粉体碳酸钙含量较小,PP纺粘非织造布的面密度较大时,断裂强力有增加的趋势,当面密度较小时,断裂强力随碳酸钙含量的增大呈下降的趋势。在小变形下,碳酸钙的加入使改性PP纺粘非织造布的初始模量有了小幅度的提高,纤维直径有增大的趋势,同时布面柔软性也会随无机粉体碳酸钙含量的增加而逐渐减小。     

用即弃聚丙烯纺粘法非织造布的可光降解研究

通过在聚丙烯中加入掺杂1%(质量分数)Cu2+的锐钛矿型纳米TiO2作为光敏剂,采用纺粘法设备制备TiO2光敏剂含量为0.0%~1.2%的聚丙烯纺粘法非织造布。将其置于70℃、340 nm紫外光下进行光降解试验,研究样品的力学性能、结晶度和表面形态的变化。结果表明:在聚丙烯中加入Cu2+掺杂的锐钛矿型纳米TiO2,可以催化聚丙烯纺粘法非织造布的光氧化降解和加快降解速度,且在实验范围内光敏剂的含量越大,其光催化降解作用越强。     

聚丙烯SMS非织造手术衣材料热处理温度研究

研究了聚丙烯纺粘-熔喷-纺粘复合(SMS)非织造手术衣材料在热处理过程中,材料结晶结构与结晶度的变化规律,以及热处理温度对力学性能的影响,结果表明:热处理温度的变化不会改变非织造布的内部晶型结构,非织造布的结晶度随热处理温度的升高而增大,晶粒尺寸随热处理温度升高先增大后减小.随热处理温度的升高,纵横向断裂强力和断裂伸长均呈现出先减小后增大的趋势,为获得更完善的晶型以及稳定的力学性能,合适的后整理温度为110～130℃.     

纺粘非织造布制备工艺与性能的关系

为研究纺粘非织造布生产工艺、结构及性能三者之间的关系,以聚丙烯为原料,采用多种工艺制备了纺粘非织造布,测试了纺粘非织造布的结构和透气性能,并对其孔隙率进行计算。通过对测试结果进行分析发现:当计量泵频率一定时,网帘频率增加,织物厚度、面密度减小,而孔隙率增大;当网帘频率一定时,计量泵频率增加,织物厚度和面密度呈变大的趋势,而孔隙率呈减小趋势;当计量泵频率增加到一定程度时,熔体输出量将不再对纤维直径变化产生明显影响;纺粘非织造布的透气率随试样孔隙率增大而提高,且二者呈幂函数关系。     

低面密度PE/PP双组分纺粘非织造布的制备及其性能

为获得具有优异柔软度和透气性的卫生用纺粘非织造布,通过改变聚合物原料和工艺参数控制纺粘非织造布的纤维类型、纤维细度和面密度,制备不同纤维细度和面密度的单/双组分纺粘非织造布,研究面密度对纺粘非织造布性能的影响。结果表明：纺粘非织造布的断裂强力、断裂伸长率、厚度随面密度的增加而增加,不匀率、透气性、柔软度随面密度的增大而减小;同一面密度下,聚乙烯/聚丙烯(PE/PP)双组分纺粘非织造布的厚度、断裂伸长率、柔软度和透气性均优于聚丙烯(PP)纺粘非织造布,而断裂强力相对略低。低面密度(15 g/m²)PE/PP双组分纺粘非织造布的纤维原料细度为21.6μm,织物弯曲长度为1.28 cm,透气量为6 995.1 mm/s,其柔软度、透气性有显著提高,可用作一次性卫生用品包覆材料。     

热轧工艺对纺粘热轧非织造布力学性能的影响

分析了聚丙烯纺粘热轧非织造布的热轧黏合机理,其结构可以用薄膜区一纤维区两相结构来描述.研究了热轧工艺对纺粘热轧非织造布力学性能的影响.在面密度一定的条件下,提高轧棍温度有利于增加薄型纺粘法非织造布的强力;在其他条件不变的情况下,提高轧棍压力有助于改善非织造布的力学性能,而提高轧棍线速度则会使非织造布强力下降;在生产高面...     

原料对聚丙烯纺粘法非织造布物理机械性能的影响

从聚丙烯切片、色母粒和分子量调节剂等聚丙烯非织造布生产原料着手．分析了对聚丙烯纺粘法非织造布物理机械性能的影响，说明了对纺粘法非织造布来说，原料的选择非常重要。     

热处理对聚丙烯熔喷非织造布性能的影响

聚丙烯非织造布的晶型和结晶度对温度变化敏感,材料的各项性能与其密切相关。在不同温度下对聚丙烯熔喷非织造布进行热处理,并进行电晕放电驻极,对热处理后聚丙烯熔喷非织造布的结晶结构和性能进行研究。结果表明:随着热处理温度的升高,聚丙烯熔喷非织造布的晶型由拟六方晶型逐渐向α晶型转变,结晶度和晶粒尺寸也随之增大;热处理温度对聚丙烯熔喷非织造布的强力及伸长率、透气性、表面静电势和过滤性能均有较大影响;110℃下热处理的聚丙烯熔喷非织造布的驻极性能和过滤效能最好。     

新投入生产的纺粘法非织造布

<正>位于俄罗斯联邦鞑靼共和国经济特区Алабуга的Полиматиз股份公司非织造布生产厂于2009年7月15日正式开工。该工厂计划生产纺粘法(S)和熔喷法(M)聚丙烯非织造布、纺粘—熔喷—纺粘(SMS)三层非织造布和纺粘—熔喷—熔喷—纺粘(SMMS)四层非织造布。纺粘法与熔     

纺粘法非织造布生产技术现状及发展趋势

纺粘非织造布是将化纤的纺丝和非织造布的成网、固化技术相结合的工艺技术。近几年，纺粘法非织造布的生产技术得到了长足的进步，一些新技术的应用也为纺粘法产品的发展开拓了新的空间。文章介绍了国内外纺粘法非织造技术的现状，分析了国内外的差距，并指出了纺粘技术的发展趋势。     

In vitro faecal fermentation outcomes and microbiota shifts of resistant starch spherulites

In the present study, we prepared A- and B-type polymorph-resistant starch spherulites (RSSs) with a wide range of crystallinity, and elucidated the relation between crystalline structure and faecal microbial fermentation outcomes. A- and B-type polymorphic RSSs displayed similar fermentation rate throughout entire process with final gas production of 11.8–13.2 mL, suggesting that the crystalline pattern and crystallinity cannot effectively control the fermentation rate of starches. The acetate and butyrate concentration of A-type RSS decreased with the increase of crystallinity respectively, and highly crystalline B-type RSS reduced the production of acetate (8.4 mM) and propionate (2.1 mM). RSSs with different crystalline types showed similar microbial community structure but distinct key bacteria species. A-type RSSs greatly promoted the abundance of butyrogenic bacteria (i.e., Roseburia faecis and Lachnospiraceae), whereas B-type RSSs tended to proliferate Prevotella copri associated with propionate production. Our findings shed new light on design and manufacture of starch-based functional ingredients with enhanced gut health.     

氯化钠结晶工艺优化设计

2011年我国国内医药用氯化钠产量已超10万t,产品基本采用多效真空蒸发结晶工艺,普通工艺生产的产品结晶在储存过程易出现板结,给流转、使用带来非常大的问题.通过对氯化钠生产过程中的成核、结晶理论进行分析,将套筒隔室武结晶技术和延时结晶技术相结合,使氯化钠产品晶体结构、粒度及品质有了很大的提高.通过研究表明,新工艺生产的氯化钠产品粒径达0.75 mm以上,晶体呈椭圆型（鱼籽状）,产品质量指标优于注射级氯化钠产品标准,是解决氯化钠结晶在储存过程板结、结晶生长致硬块化的很好途径.     

纺粘-熔喷复合材料的加工与应用

纺粘-熔喷复合材料可以采用在线复合和离线复合两种加工方法制得,产品既具有纺粘非织造布的高度和耐磨性,又兼有熔喷非织造布的良好的过滤性能、保温性能和导湿性能,其应用范围广泛.纺粘-熔喷复合材料将向更轻薄、更宽幅,提高生产速度、降低纤维纤度和使用新型聚合物原料的方向发展.     

纳米银PP抗菌纺粘布的开发

研究了纳米银抗菌添加剂改性的PP纺粘布的生产工艺过程,对其抗菌性、耐洗涤牢度、力学和光老化性能进行了测试,并与同规格的常规PP纺粘布做了比较。结果表明,纳米银抗菌添加剂在PP大分子中分散均匀,改性后的产品不但抗菌性能优良,而且对纺粘布的力学性能和色泽都不会产生很大影响。     

挤压膨化和焙烤工艺对代餐粉特性的影响

以糙米、紫米、红米、大米、玉米等谷物为原料,辅加山楂、薏苡仁、山药、莲子、赤小豆、黑豆等药食同源物质,分别采用烘焙、挤压膨化等工艺制备代餐粉。分析了不同加工方式对谷物代餐粉微观形貌、晶体特性和糊化特性的影响。结果显示: 加工后淀粉圆形的颗粒结构减少或消失,形成较大的不规则颗粒结构,结构疏松。挤压膨化代餐粉晶体结构从A型转变成V型,其脂肪含量、糊化焓变、回生值、峰值时间、晶体结晶度比烘烤代餐粉低,吸水性指数、水溶性指数、衰减值均高于烘烤代餐粉。因而,挤压膨化代餐粉蛋白质损失较少,脂肪含量显著降低,不易老化,具有较好的产业化价值。     

Ball Milling of Amaranth Starch-Enriched Fraction. Changes on Particle Size,Starch Crystallinity,and Functionality as a Function of Milling Energy

Starch-enriched fractions of amaranth grain were obtained from planetary ball milling and subsequently studied for particle size reduction, hydration properties, and crystallinity loss. Wide-angle X-ray scattering (WAXS) was used to evaluate the crystalline of starch-enriched fractions, using an iterative smoothing algorithm to estimate amorphous background scattering. This methodology was then used to determine initial crystallinity and monitor crystallinity loss during this process. The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) showed that ball-milling treatment significantly decreased (p?<?0.05) the intensity ratios of the bands at 1,039 and 1,014 cm^?1 corresponding to the crystalline/amorphous part of starch structure. Starch crystallinity degree decreased by ball milling due to starch amorphization during this process. An excellent correlation was found between crystallinity degree obtained by WAXS and ATR-FTIR data for the whole ball-milled-analyzed samples. The energy required for size reduction was satisfactorily explained using a generalized grinding equation. A decrease of span and median diameter (D ₅₀) indicated sample homogenization during ball milling. Water absorption index and water solubility increased with crystallinity loss during process. The flour produced at the higher milling energy (6.52 kJ/g), with a mean size of 68?±?1 μm, showed a low crystallinity degree (<5 %), and high water absorption and solubility indexes in comparison to the starch-enriched fraction sample. Particle activation provided by ball-milling process can offer chances for starch application such as sorbent agent in food or pharmaceutical industries.     

Comparative study of deteriorative changes in the ageing of milk powder

Skim milk powders produced by spray drying (mostly amorphous) are commonly used in downstream food industries and have to be stored for long times after production before final use. However, their physicochemical qualities and properties decline during long-term storage due to the hygroscopicity of amorphous lactose. Surface modification of particles by crystallisation of the outer layer, giving so called “egg-shell” particles, has shown significant improvements in the physical properties of the powder in their fresh state. In this study, the raw powder and processed powder (with modified surface) were stored at around 33% relative humidity and 25–30 °C for 30 weeks to investigate the effect of ageing on these two types of powders. Agglomeration, large lactose crystal formation on the surface, surface composition changes and protein modifications were studied. The changes between the raw powder and process powder were compared after ageing. The non-hygroscopic crystalline surface layer showed significant benefits in maintaining the physicochemical qualities of the powders over long storage times. The aged raw powder showed a 24% change in the crystallinity, a 3% change in the lactose/protein ratio on the surface and 6% protein denaturation compared with the aged processed powder with a 4% change in the crystallinity, a 1.5% change in the lactose/protein ratio on the surface and 2% protein denaturation, respectively, after 30 weeks storage.     

回用过程对二次纤维聚集态结构和成纸性能的影响

采用XRD、FT-IR以及NMR研究了桉木纤维经多次回用后聚集态结构的变化规律,进一步研究了聚集态结构改变对成纸性能的影响。结果表明:随着回用次数的增加,纤维素的结晶度增大,002面微晶尺寸随着回用次数的增加而增加,红外结晶指数增大并且和结晶度有很好的一致性;而NMR研究计算得到的结晶度明显小于XRD计算得到的结晶度,可能对于13CNMR,只有晶区内的部分才看做结晶区;回用后抗张指数和耐破指数减少,经过5次回用后抗张指数和耐破指数分别下降了61.61%、10.57%,撕裂指数先增大后减小,5次回用后,下降了33.07%。由于回用导致纤维聚集态结构中的晶区和非晶区的比例发生了变化,这种聚集态结构的变化最终导致了成纸性能的衰变。