Production of leather under the influence of compressed carbon dioxide

The leather producing industry transformes untreated hides that may rot under wet conditions and are brittle under dry conditions into durable, imperishable leather by processes which incorporate tanning agents into the hides. Several steps can be enhanced by high pressure technology. For the tanning of skins compressed carbon dioxide can be used to shorten tanning times, to reduce water pollution and to save leather-finishing-fats. This presentation focuses on the time retrenchment of the tanning-step. Typically, about 30 h are used to tan skins with chrome. At increased pressures between 30 and 100 bar it could be shown that time can be saved by a factor of 6 to 5 h. The presentation will demonstrate the process principle, the acceleration of the tanning process and a quantitative analytical method for monitoring the tanning success via the ion content in the tanning liquid.