Proteases in Leather Processing

2016 ◽  
pp. 209-238
Keyword(s):  
Leather Processing

STUDI OF FRUIT LEATHER PROCESSING OF MANGGO

2013 ◽  
Vol 3 (2) ◽  
pp. 124-132
Author(s):  
Yessy Rosalina ◽  
Laili Susanti ◽  
Tatik Sulasmi
Keyword(s):  
Thin Sheet ◽  
Physical Appearance ◽  
The Other ◽  
Drying Temperature ◽  
Fruit Flesh ◽  
Leather Processing ◽  
High Yielding Varieties ◽  
Processing Techniques

Mango varieties Bengkulu is one of high yielding varieties from Bengkulu Province. The plants grow well and produce fruits almost year-around in all regions in the province of Bengkulu. Mango varieties Bengkulu have very large fruit, thick fruit flesh and slightly sour flavors. It makes Mango varieties Bengkulu is very suitable to be consumed in the form of a processed. Fruit leather is one form of processed fruit. Fruit leather is a thin sheet of fruit in dried form. The results showed that the best processing techniques of fruit leather for mango varieties Bengkulu is the process with addition of sugar by 20% and drying temperature at 60 ?C. The treatment produce fruit leather with the best physical appearance and flavor compared with the other treatments.

scholarly journals Enzymes for Leather Processing: Effect on Pickling and Chroming

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1480
Author(s):  
Renata Biškauskaitė ◽  
Violeta Valeikienė ◽  
Virgilijus Valeika
Keyword(s):  
Mechanical Properties ◽  
Acidic Medium ◽  
Proteolytic Enzymes ◽  
Relative Elongation ◽  
The Other ◽  
Shrinkage Temperature ◽  
Processing Effect ◽  
Leather Processing ◽  
Production Processes ◽  
Pickling Process

Recently, increasing attention has been paid to the application of enzymes in a wide variety of leather production processes. The aim of the present study was to investigate the action of enzymatic pickling on derma’s collagen and the influence of this action on subsequent processes and properties of chromed and finished leather. The application of active in acidic medium proteolytic enzymes in the pickling process led to an additional impact on derma structure: collagen was more strongly affected and the porosity of the pelt dermis was reduced, but the hide became more thermally stable. The enzymatically pickled pelt bonded more chromium and reached higher shrinkage temperature while chroming; dyes penetrated deeper; such leather bonded more fatliquors. On the other hand, the action of enzymes worsened the physical–mechanical properties of the leather, as the experimental leather was weaker than the conventional one. The first was characterised by weaker grain layer and had significantly higher relative elongation. Therefore, as some properties improve and others worsen during such a process, the application of every enzyme should be carefully investigated and optimized to produce a leather with defined properties.

Synthesis of Formaldehyde Free Amino Resin to Produce Green Eco-Labelled Leather with Improved Retanning Properties

2020 ◽  
Vol 115 (4) ◽  
pp. 132-139
Author(s):  
Muhammad Naveed Ashraf ◽  
Shahzad Maqsood Khan ◽  
Shahid Munir ◽  
Rashid Saleem
Keyword(s):  
Thermal Stability ◽  
Water Solubility ◽  
Thermo Gravimetric Analysis ◽  
Sulfanilic Acid ◽  
Gravimetric Analysis ◽  
Melamine Resin ◽  
Organoleptic Properties ◽  
Formaldehyde Content ◽  
Leather Processing ◽  
Percentage Efficiency

Formaldehyde has many applications in the chemical industry including synthesis of amino resins which are used in leather processing. After application in leather, these resins are hydrolyzed under certain conditions to release free formaldehyde which has high environmental concerns due to its proven carcinogenic effects. The objective of this work is to develop a formaldehyde free melamine-based resin to produce green leather with improved retanning properties and thermal stability. The optimum melamine resin was synthesized by condensing melamine with glyoxal instead of formaldehyde. Further, the water solubility and improved thermal stability of synthesized melamine resins were achieved by introduction of sulfanilic acid in resin structure. Synthesized resin was used in leather retanning in comparison with commercially available melamine resin as a control. Both leathers were tested for mechanical properties, organoleptic properties, grain surface and fiber structure analysis. Comparative free formaldehyde content was measured in resultant leathers. Effluents of retanning baths were comparatively analyzed. Optimum resin was also characterized by thermo gravimetric analysis and FTIR. The results of this study showed that the experimental resin has imparted significant improvement in mechanical and organoleptic properties of leather as compared to the control resin. Analysis of free formaldehyde content confirmed the absence of free formaldehyde in leather treated with optimum resin while 141 mg/kg formaldehyde was detected in leather treated with control resin. Free formaldehyde was also absent in effluent of experimental resin while 305 mg/kg formaldehyde was detected in effluent of control resin. Moreover, percentage efficiency in COD, TDS and TSS load of effluent was observed as 9.62, 7.2 and 6.31 respectively.  Resultant leather was free from formaldehyde making it safe for human along with reduction in pollution load of tannery.  

Use and minimization of water in leather tanning processes

1999 ◽  
Vol 40 (1) ◽  
pp. 237-244 ◽  
Author(s):  
O. Tünay ◽  
I. Kabdaşlı ◽  
D. Orhon ◽  
G. Cansever
Keyword(s):  
Water Use ◽  
Water Conservation ◽  
Complex Structure ◽  
Extensive Study ◽  
Pollution Load ◽  
Leather Processing ◽  
Leather Tanning ◽  
High Pollution ◽  
The Subject ◽  
Tanning Industry

Minimization of water use and reuse applications within industry has recently gained importance within the context of water conservation efforts. The leather tanning industry is one of the subject industries due to large amount of water to be disposed of together with a high pollution load. The leather tanning industry has a complex structure in terms of materials, processes and manufacturing practices. Therefore a systematic approach is required to assess water use practice. In this study, bovine leather processing was taken as an example. An extensive study was conducted as on-site evaluations and questionnaires in the İstanbul Organized Leather Tanning District to assess water use practices, patterns and minimization trends. Results of the study were discussed and important aspects of water minimization practices have been pointed out.

scholarly journals Bio-agent de retanare utilizat in procesarea pieilor si procedeu de obtinere

2019 ◽  
Vol 70 (11) ◽  
pp. 3878-3880
Author(s):  
Rodica Roxana Constantinescu ◽  
Gabriel A. Zainescu ◽  
Marian Crudu ◽  
Gheorghe Bostaca
Keyword(s):  
Waste Treatment ◽  
Leather Industry ◽  
Complex Products ◽  
Leather Processing ◽  
Protein Waste ◽  
Starting Point ◽  
Filling Agent ◽  
Treatment And Disposal ◽  
Biochemical Degradation ◽  
Very High

Currently, the leather industry has to deal with very high costs for waste treatment and disposal. As a result, it is recommended to subject the organic protein waste from tanning to biochemical treatments for recycling in the industry. The degree of novelty lies primarily in the fact that the starting point of the promoted technologies is obtaining new complex products by processing organic waste and using it in tanneries. The lime fleshings resulting from the hide fleshing operation represents the highest amount of reusable leather material of approx. 25%. This paper presents an innovative process for the biochemical degradation of hide waste resulting from hide fleshing in order to obtain a retanning/filling agent used in leather processing.

A novel Synthesis, Chemical Characterization and Biological Activities of Metal-Leather Protein Hydrolysate Chelates

2021 ◽  
Author(s):  
Rania Jacob ◽  
Hazem Hassan ◽  
Adel Afify ◽  
Gamal Gabr
Keyword(s):  
Melting Point ◽  
Protein Hydrolysate ◽  
Biological Activities ◽  
Chemical Characterization ◽  
Antibacterial Activities ◽  
Biochemical Properties ◽  
Mineral Salts ◽  
Mineral Absorption ◽  
E Coli ◽  
Leather Processing

Abstract Leather industries covers a wide chain of production and indirectly contributes to the economic flow. The different stages used in leather processing led to produce huge solid waste volumes. Because of the great effectiveness of amino acids as naturally chelates for minerals, the present study was carried out to recycling leather waste into its protein hydrolysate by CaO hydrolysis. The Leather protein hydrolysates (LPHs) was used to prepare metal-leather protein hydrolysate chelates (Cu2+-, Zn2+-& Fe2+-LPHCs) and some of their physical properties (i.e. λ-max, FTIR spectra, color, melting point) and biochemical properties as its antibacterial activity, as well as using as micronutrient elements for plant were evaluated. Results showed that the Cu2+-LPHC gave the highest value of melting point and λ-max than other chelates. All chelates shifted the vibration bands toward a higher frequency than LPH/CaO. Metal-leather protein hydrolysate (M-LPHCs) had antibacterial activities against E. coli, B. cereus and Micrococcus spp. mostly with Zn-LPHC and Fe-LPHC. These complexes also increased the growth characteristics and mineral absorption of spinach plants in hydroponic nutrient solution than that of mineral salts (CuSO4, ZnSO4 and FeSO4). Finally, the study concluded that M-LPHCs can be used as antimicrobial agent, micronutrients for plant and support the minerals bioavailability in animals.

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