Application of Microbial Transglutaminase in Leather Processing
|Keywords||Leather Microbial transglutaminase Gelatin Casein Polyurethane Tanning Wet processing after tanning Finishing|
The tanning industry faces three major problems: (1) serious environmental pollution. Tannery waste water from the wet-processing unit is a major pollution. (2) low resource utilization, waste. (3) a large quantity of water. Due to the rising price of raw materials and chemical materials and environmental protection efforts have been enhanced, is a serious threat to the tanning business development. The leather industry is facing a new change in the situation, and this change in the situation of the core environmental issues. Therefore, the tanning industry is an urgent need for reform. Fundamental reform measures is the implementation of cleaner production and eco-manufacturing of the leather. As environmentally friendly biological materials enzyme specificity, efficiency, specificity, mild reaction conditions, pollution-free and biodegradable. Leather production, enzyme replacement of traditional chemical reagents to reduce environmental pollution. Microbial transglutaminase (MTG, EC188.8.131.52) are widely used in the food and textile industries, such as the preparation of a heat is used to improve food taste and nutritional value of the protein, and the anti-water film, enhanced wool anti-felting and dyeing and so on. This thesis MTG for leather processing in order to examine the MTG effect leather performance, compared with the original process, and to explore the MTG whether it can replace or partially replace some of the original processing environment contaminated material. Main results are as follows: (1) in the leather tanning process, the MTG processing leather, compared with the samples treated without enzyme, the shrinkage temperature (Ts) and softness was no significant improvement. However, compared to using only the chromium tanning agent Chromosal B processing leather, using MTG processing, then chrome tanned leather samples, its shrinkage temperature reduces 9 ° C. (2) in the wet processing step, after the tanning, the MTG-modified gelatin sodium caseinate as a filler treating leather capable of improving some of the organoleptic properties such as firmness of the grain, the grain surface smoothness and plumpness of the leather, and mechanical properties such as tensile strength, tear strength extending and unilateral no significant effect on the leather. The microscopic structure of the leather sample was observed by scanning electron microscopy and found that the collagen fibers of the treated sample distribution is more regular than the untreated samples and close. And results in different processes, staining or Fatliquoring treatment, the most obvious effect. (3) with a mixture of the MTG modified gelatin and casein, gelatin, casein ratio of 2:2,1:3, and 0:4, forming a film mechanical properties (tensile strength and elongation at break ratio) has been improved; to increase the concentration of enzyme, its elongation at break is significantly increased, and the enzyme concentration is 10% maximum, while the tensile strength little change; the modified gelatin - casein (GC) and polyurethane (PU) with different The mixing ratio, the mixed film (PU-GC) of the mechanical properties and water resistance are significantly enhanced with increasing PU content. The modified GC and PU-GC mixed system for leather finishing process, system application results vary in different proportions, considering the GC than mixing ratio of 2:2 when and PU (ie the ratio of 2: 2 PU-GC11) finishing leather best. MTG modified GC13 and GC11 for leather and chemically modified casein paint primer, a comprehensive comparison, the GC11 finishing dermoid closest to the chemical modification of casein the dermoid finishing performance.