ISO 5431-2013 pdf free download

ISO 5431-2013 pdf free download.Leather — Wet blue goat skins — Specification
Cuir — Peaux de caprins a l’état “bleu humide” — Specifications.
4.2 Tanning
After pretanning operations, the skins shall be tanned with basic chromium sulfate as the primary tanning agent. The cut cross-section shall be such that the skin is completely penetrated by the bluish colour of the chromium sulfate when examined visually. Tanning shall be carried out at a pH of 3,0 or above.
4.3 Fungicidal additives
Fungicides shall be used to inhibit mould growths in the wet blue goat skins.
NOTE 1 Fungicides used to inhibit mould growth and pigmentation in wet blue goat skins should be effective and should not cause a health hazard. The types of fungicide used and their dosage should preferably be agreed between the purchaser and the supplier
NOTE 2 Fungicides should preferably be applied in quantities appropriate to ensure storage for up to 4 months at the temperature and humidity prevailing during storage or transportation.
4.4 Presentation
Wet blue goat skins shall be well fleshed, and the grain side shall be free from hair, including short hair and fine hair. The size and grading shall be as agreed between the interested parties.
NOTE The skins should preferably have a tight grain and be free from creases, drum folds and stains caused by iron salts. At least 95 % of the number of pieces In a lot should be free from stains caused by chromium salts, and the aggregate of the stained area in any one piece should not exceed 10% of the total area of the piece.
4.5 Shrinkage temperature
The shrinkage temperature shall not be less than 95 °C, when determined using the method specified in ISO 3380.
4.6 Chemical requirements
Wet blue goat skins shall comply with the requirements given in Table 1.
NOTE A minimum shrinkage temperature of 95 °C would normally require minimum chromic oxide content of 3,0 % relative to the dry mass, as determined by the method given by ISO 5398-1. Once the chromic oxide content has been determined in this way, it can be used to estimate how much more chromic oxide has to be added to achieve the desired level (I.e. the extent of further rechroming)
5 Sampling
5.1 Sampling for routine testing
The number and location of laboratory samples taken for routine testing shall be as agreed between the interested parties.
5.2 Sampling in case of dispute
The number of samples shall be as given in Table 2 and the location shall be as specified in Iso 2418.ISO 5431-2013 pdf free download.