This helps liming chemicals to act evenly and is considered a useful Pre-fleshing step 30 H2O @20oC Drum liming –40% 0.1 non ionic grease and –0.15 (2rpm) scud Drum 5mins dispersant 1.5 sodium sulphhydrate. –2.0 NaHS (70%) Drum 20 –30mins Drum continuously for 20mins. 2% sodium sulphide conc (60%) Further drumming for 3-5mins/hr for 3% slaked lime 2.5hrs 270% H2O Drum for for 4-5hrs. Rest overnight (12-15hrs). Drain bath 300% soft H2O @30oC Rinsing Drum 5mins Fleshing 250% soft H2O@25oC Washing Drum 10-15mins. Drain 100% H2O@30oC Deliming Drum 20mins. Drain out half of 0.5% Ammonium sulphate the 0.2% Sodium bisuphite bath 2% Ammonium sulphate Drum 15mins 0.15 Formic or HCl (1:10) –0.3% 0.2% non ionic grease and scud dispersant Drum 30-40mins. float pH 8.2 –8.5 100% H2O@32oC Bating Drum 30mins. The pH is maintained between 8.2&8.5 by 0.3% enzymatic bate. adding formic acid if necessary. Drain bath 200% H2O@25oC Washing Drum 15mins. Drain 40% H2O Pickling 7% Salt to make 8oBe Drum 10mins 0.3% formic acid (1:10) Drum 15mins 0.8% sulphuric acid (1:10) Drum 1-1.5hrs. Float pH 2.6-2.8 Tanning 3-4% chrome crystals (33%
Pre-fleshing This helps liming chemicals to act evenly and is considered a useful step Drum liming 30 –40% H2O @20oC (2rpm) 0.1 –0.15 non ionic grease and scud Drum 5mins dispersant 1.5 –2.0 sodium sulphhydrate. NaHS (70%) Drum 20 –30mins 2% sodium sulphide conc (60%) Drum continuously for 20mins. Further drumming for 3-5mins/hr for 2.5hrs 3% slaked lime 270% H2O Drum for for 4-5hrs. Rest overnight (12-15hrs). Drain bath Rinsing 300% soft H2O @30oC Drum 5mins Fleshing Washing 250% soft H2O@25oC Drum 10-15mins. Drain Deliming 100% H2O@30oC 0.5% Ammonium sulphate Drum 20mins. Drain out half of the bath 0.2% Sodium bisuphite 2% Ammonium sulphate Drum 15mins 0.15 –0.3% Formic or HCl (1:10) 0.2% non ionic grease and scud dispersant Drum 30-40mins. float pH 8.2 –8.5 Bating 100% H2O@32oC Drum 30mins. The pH is 0.3% enzymatic bate. maintained between 8.2&8.5 by adding formic acid if necessary. Drain bath Washing 200% H2O@25oC Drum 15mins. Drain Pickling 40% H2O 7% Salt to make 8oBe Drum 10mins 0.3% formic acid (1:10) Drum 15mins 0.8% sulphuric acid (1:10) Drum 1-1.5hrs. Float pH 2.6-2.8 Tanning 3-4% chrome crystals (33%
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