Gelatine solutions are pure protein solutions. They are very complex liquids and need special attention for filtration. Depending on the raw material used (hides, skins or bones) the quality differs widely. During the process there are usually a number of filtrations required, ranging from coarse to fine and finally to sterile filtration. Depending on the process, the gelatine concentration (50 - 200 bloom) and working temperature, the filtration rates vary widely and range from 80 - 120 - 200 l/m2/h.
The plants must be built to withstand prolonged high processing temperatures of 95°C - 98°C. During the process a sterilizing and/or bleaching chemical (hydrogen peroxide) may be used (pH 1 - 14) and for this reason all parts, which come into contact with the product, must be of a high quality stainless steel AISI 316L (1.4435) or better.