【作者】 张业聪；

【导师】 付丽红；

【作者基本信息】 山东轻工业学院 ， 皮革化学与工程， 2008， 硕士

【摘要】 利用热台偏光显微镜,通过测定皮纤维的热收缩温度、热收缩率及其收缩曲线,通过测定脱铬液中水解胶原量和皮块铬含量的方法,研究了蓝湿皮脱铬过程中,浸水、浸灰、草酸、柠檬酸钠等不同工序对皮纤维的干热性能和湿热性能的影响;并对不同工序处理的皮块厚度上不同层次的皮片及其纤维的热性能进行了研究。结果表明:(1)不同脱铬材料对皮纤维的干热性能的影响不同。浸水使皮纤维间距增大,部分氢键、电价键结合被破坏,纤维收缩率曲线的爬行期长,转折点不明显;经石灰、草酸、柠檬酸钠处理后的纤维的收缩曲线变化趋势相似,纤维收缩曲线的转折点明显;不同工序处理后纤维收缩率和DTs由大到小的顺序为:草酸>浸水>蓝湿皮>柠檬酸钠>浸灰,蓝湿皮>柠檬酸钠>浸灰>浸水>草酸;石灰脱铬使皮纤维热性能增强,脱铬时间增加,皮纤维的热收缩率降低、DTs越高、收缩率曲线的转折点明显;草酸脱铬时间越长,皮纤维收缩率越高、收缩温度越低,处理时间不同,纤维的热收缩曲线变化趋势相似;柠檬酸钠脱铬过程使皮纤维热性能增强,脱铬时间增加,皮纤维的热收缩率降低,收缩温度高,收缩转折点明显。(2)脱铬过程中,皮块的铬含量下降,胶原结构的稳定性降低,胶原水解量增加,皮块的湿热稳定性(Ts)随脱铬材料的不同而不同。石灰和草酸脱铬伴随胶原水解,皮胶原的结构稳定性降低,皮块的湿热稳定性下降;柠檬酸钠具有脱铬和交联皮胶原的双重作用,随脱铬时间的增加,皮块的铬含量下降,胶原水解量增加,皮块的收缩温度上升。(3)皮片的热稳定性主要与纤维间的交联有关,而其纤维的热稳定性主要与纤维的无定形与结晶区有关。纤维间的交联越多,皮片的结构稳定性越好、DTs越高、收缩率越低。蓝湿皮及其浸灰后,皮片的热稳定性明显高于其纤维的热稳定性,粒面层和肉面层皮片及其纤维的热稳定性高于中层,而且肉面层的热稳定性高于粒面层;草酸处理后,粒面层纤维的热稳定性高于皮片的热稳定性,肉面层和中层纤维的热稳定性低于皮片的热稳定性,粒面层和肉面层的热稳定性高于中层,肉面层的热稳定性高于粒面层;柠檬酸钠使皮片的热稳定性高于纤维的热稳定性,中层皮片和纤维的热稳定性高于粒面和肉面层,肉面层的热稳定性高于粒面层。采用热台显微镜对山羊猾子皮在加工过程中,浸水、酶软化、鞣制、加脂对羊毛纤维的耐干热性能包括热收缩率和收缩温度进行了研究。结果表明,浸酸和加脂对提高毛纤维的耐干热性能有明显的作用,而鞣制能一定程度上降低毛纤维的耐干热收缩性能;加脂剂的种类和数量对毛纤维耐干热性能有较大的影响;酶处理使毛纤维的最终收缩率下降。利用正交实验设计并通过极差分析方法,对明胶提取过程中影响明胶冻力和下胶量的因素进行了研究,并对明胶喷雾干燥条件进行了优化。结果表明,各提胶因素对明胶冻力和下胶量的影响由大到小的顺序分别为:温度>时间>pH,温度>pH>时间,最适工艺参数为温度62℃、pH值5.28、时间4.0h;喷雾干燥各因素对明胶冻力和粘度的影响由大到小的顺序为:进料量>明胶液浓度>抽风量>进口温度,抽风量>进料量>明胶液浓度>进口温度,对明胶得率和水分的影响次序均为:明胶液浓度>进料量>抽风量>进口温度。最适工艺条件:明胶液浓度5%～6%、进料量18mL/min、进口温度170～175℃、抽风量35～37 m~3/h。更多还原

【Abstract】 The dry and wet heat properties of fibers on dechroming processes including soaking, liming, oxalic acid and sodium citrate are studied by determining the shrinkage temperature, shrinkage ratio and curve using thermal platform microscope and the collagen hydrolyzing in solution and content of chromium in leather, and moreover, the thermal properties of skin graft and fibers on different layers of skin after dechroming processes are analyzed. The results showed that:(1) It plays different effects on dry heat properties with different materials. The space between fibers becomes big by soaking, and a part of the hydrogen bond and electrovalent bond is destroyed, the shrinkage curve is crawling too long and the turning point is indistinct. The changing trends of shrinkage curves are similar after using lime, oxalic acid, sodium citrate, and the turning point is distinct. The sequence of shrinkage ratios and shrinkage temperatures after different processes from big to small is: oxalic acid>soaking>wet blue>sodium citrate>liming, wet blue>sodium citrate>liming>soaking>oxalic acid. The dry heat properties can be enhanced by liming and the shrinkage ratio is lower, shrinkage temperature is higher with the time of liming becoming long. The shrinkage ratio is higher and shrinkage temperature is lower with the time of oxalic acid dechroming becoming long. The changing trends of shrinkage curves are similar after dechroming different time. The dry heat properties can be enhanced using sodium citrate, and the shrinkage ratio is reduced, shrinkage temperature is increased with the time going on, and the turning point is distinct.(2) The content of chromium reduces on dechroming processes, the stability of collagen structure is decreased, and the collagen hydrolyzing is enhanced. The hydrothermal properties (Ts) of wet blue were different as dechroming materials. The quantity of dechroming and collagen hydrolyzing are enhanced with the oxalic acid and lime dechroming time going on, the stability of collagen structure is destroyed. The hydrothermal properties of wet blue are reduced. The sodium citrate plays effects on dechroming and cross-link among collagen fibers, so the content of chromium reduces, collagen hydrolyzing is enhanced, but shrinkage temperature rises with dechroming time becoming longer.(3) The thermal stability of skin graft relates to cross bonding, but the fibers relates to amorphism and crystal regions. The cross bonding is more, the thermal stability is higher, and the shrinkage temperature is higher, the shrinkage ratio is lower.The wet blue and being liming, the thermal stability of skin graft is higher than fibers, and, the thermal stability on both sides of the skins is higher than middle, the flesh layer is higher than grain layer. After dealing with oxalic acid, the thermal stability of fibers are higher than skin graft on grain layer, but lower on both flesh and middle layers, and, the thermal stability on both sides of the skins are higher than middle, the flesh layer is higher than grain layer. Sodium citrate can make the thermal stability of skin graft higher than fibers, and, the middle is higher than other sides, the flesh layer is higher than grain layer.The dry heat shrinkage behaviors of wool fibers are studied by the thermal platform microscope during the processing of sheepskin as well as the effects of different tanning agents, fatliquors, enzyme on the wool fibers. The results showed that both pickling and fatliquoring can improve the dry heat shrinkage behaviors of wool fibers, but the tanning can not. The kinds and numbers of fatliquors play important effects on the dry heat shrinkage behaviors. The enzyme can also reduce the final contraction percentage.The changing rules of effect factors of gel strength and quantity of gelatin are studied by orthogonal design and range analysis, and moreover, the spray-drier technology of jelly powder is optimized. The results showed that the effect sequence of every factor to gel strength and quantity is: temperature> time> pH, temperature> pH> time; the optimum conditions of cooking the pig raw material are: 4 hours at the temperature of 62℃and the pH=5.28; the effect sequence of every factor to gel strength and viscosity of jelly powder is: pump> solution concentration> aspirator> inlet temperature, aspirator> pump> solution concentration> inlet temperature, the yield and the moisture both are: solution concentration> pump> aspirator> inlet temperature; The optimum conditions of spray-drier preparation are: solution concentration 5%～6%, pump 18ml/min, inlet 170～175℃and the aspirator 35～37m3/h.更多还原