Browsing by Subject "nahan parkitseminen"

Making leather includes multiple phases and there are several options when executing each phase. The selected tanning method affects most to the properties of finished leather. In literature there are lots of descriptions about the methodology of how to tan furs and skins in a traditional way, but there are only a little information about the properties of these naturally tanned fur skins. The aim of this study is to analyse different kinds of traditional and environmentally friendly tanning methods to be able to make durable leather of a good quality. The research problems of this study are to find the most practical method for tanning wild furs and to analyse if it is possible to make high-quality leather by using natural ways of tanning leather. A review of the literature inspired the idea of comparing single-component tannages against a combination of two conventional tannages. The most practical methods were chosen from the traditional and the easiest ways of tanning furs. Chosen methods were tanning with tealeaves, willow (salix), sour porridge, urine, Novaltan Al and Pretanix C. The data was collected from three red foxes, which were tanned in 11 different ways: six single-component tannages and five combinations of two tannages. Fur skin properties were investigated for tear strength, elongation, water vapour permeability, shrinkage temperature, hair fastness and surface structure. The data collected was mostly numeric and it was analyzed by Spearman's rank-correlation. Scanning electron microscopic photos were taken from the leather surface and the results were compared against numeric data. This study shows that thinner leathers had better tear strength and relative elongation. Water vapour permeability results analyzed with SEM-pictures revealed that aluminium-based Novaltan Al made the leather surface smoother allowing water vapour to pass through it. Meanwhile, other tannages made the surface more spongy, possibly soaking moisture into leather. Plant based tannages had higher shrinkage temperature than any other tannages. The results showed that using two conventional tannages made the leather properties better compared to single-component tannages. The best and probably most practical tanning method according to this study was combination tanning by using tealeaves and Novaltan Al. It's important to think of the desired properties for the leather, and then choose the tanning method that makes wanted properties possible.