298 94 307/02 Untersuchungen zum Stand der Umsetzung des ...

H Concentration
See description under 1 Limed bone process.
I Sterilisation
See description under 1 Limed bone process.
J Drying
See description under 1 Limed bone process.
6.1.17.2 Hide gelatine
5 LIMED HIDE PROCESS
P Cutting
The hide splits are cut and then washed with water.
Q Lime treatment
G Ion exchange
See description under 1 Limed bone process.
Teil 3 Seite 6-22
Slaked lime (Ca(OH)2) is added until the relative density of the solution is 1.5 - 3° Bé.
The treatment takes 6 – 11 weeks. During the liming process, the lime solution is con-
trolled, the lime is refreshed and air is regularly blown through the solution, to maintain
this relative density and a pH of approximately 12.5.
R Washing and acid treatment
When the lime treatment is finished, the raw material is washed in water in order to
reach a pH of 9 - 10. Acid is then added until a pH of 1.9 – 2.0, is reached. During this
time the pH is kept at 2.4 for 2 – 3 hours. Depending on the recipe, some alternative pH
ranges or durations may be maintained, but the principle of washing and acid treatment is
always the same.
S Neutralisation
The excess of acid is removed by washing with water until a slightly acid to neutral pH of,
e.g., 5.5 – 6.5, is reached.
E Extraction
See description under 1 Limed bone process.
F Filtration
See description under 1 Limed bone process.
See description under 1 Limed bone process.
H Concentration
See description under 1 Limed bone process.
I Sterilisation