Characteristics Evaluation of Ostrich Skin That Process with Different Tanning Methods

Effect of age, body positions and different tanning methods on physical and chemical skin and leather traits of slaughter ostriches was consequently investigated. Fourteen skins representing slaughter ages ranging from six to 18 months were selected to represent means of the respective body region and tanning type with regard to age groups. Three chrome, vegetable and alum tanning type were used. The chemical tests contents total nitrogen and protein, matter soluble dichloromethane (fat), pH, water-soluble matter, water-soluble inorganic matter and water-soluble organic matter were determined. Also physical and mechanical tests, apparent density, thickness, tensile strength and percentage extension were studied. The data were analyzed by multivariate general linear model (GLM) using SAS software package. Total of main part (diagonal) and neck size were 6.78±1.1, 12.27±1.1 and 16.54±0.9 ft2 for 6, six to 12 and 12 to 18 month ages respectively. The rate of main part, neck and legs were content 81.47, 10.13 and 8.4 percent of total leather size. It was evident that leather size, breaking load and thickness increased with age (p0.05). A similar tendency was observed for tensile strength. The size of leather increased at a rate of 1.02, 0.78 and 0.9 ft2 per month in slaughter age from six to 12, 12 to 18 and overall six to 18 months respectively. There was 0.6 mm different of leather thickness between ostrich with six age and 1 years old. The tensile strength had an increasing rate for six month ostrich leather (74.77±18.11 kgf/cm2) with six to 12 month and 1 years old 97.86± 15.03 and 142.32± 12.64 kgf/cm2 respectively. There was significant difference (p0.05) for tensile strength of main part, neck and legs 109.97±9.88, 62.19±20.36 and 112.12±17.36 kgf/cm2 respectively. The chromic tanning leather had highest tensile strength and extension (127.01±12.17 kgf/cm2 and 56.83±17.36 percentage than alum tanning (97.91±10.66 kgf/cm2, 42.15±7.79 percentage) and vegetable tanning leathers (46.89±12.4 kgf/cm2 and 38.36±5.57 percentage) respectively. There was significant difference (p0.05) of tanning methods on soluble dichloromethane (fat), contents total nitrogen and protein. There was a positive correlation (p0.01) between tensile strength with percentage extension and nitrogen content. The correlation between apparent density and pH was -0.5. It was found six and four percent increases of fat matter in vegetable-tanned leather with chrome and alum-tanned leather and on the other hand fewer amounts of pH, protein and nitrogen content was found in the vegetable-tanned leather in comparison the chrome and alum-tanned leather. Probably this case was the result inverse physical performances in vegetable-tanned leather. Due to high variation were observed in physical and chemical characteristic of this study, suggestion to utilize the skin of different age and body region for special leather articles. It is necessary that practical experiments such this one do in a large scale with change in material and methods because the effects of vegetable tanning are improving.