Typical water proof sole leather Cow/Buffalo hide process

Raw wet salted buffalo hide

>  Selection Trimming, Weighing based on salted weight 

> washing:

500% - water at NT

0.15% - preservative 

30 min rest 60 min,  drain.

Soaking:

500% - Water

0.5% - wetting agent - 30 min

0.2% - preservative - 20 min

0.5% - sodium carbonate (1:20 sol) - 30 min

rest 1 hour, run 5 min/2 hrs, 8 hours O/N, run 10 min, drain

Liming:

300% - water

2.5% Na₂S (1:20 sol) - 30  min rest 30 min run

2.05% lime (1:40  sol) - 30  min rest 30 min run

2.5% Na₂S (1:20 sol) - 1 hrs rest 1 hrs run.

Run 5 min/2hrs for 3 hrs

Total duration 36 hrs, Drain, 

Washing > Scudding

> Re-liming:

400%  - water

6.0% - Lime

0.5% Na₂CO₃

1 hrs rest 1 hour, run 5 min/2 hrs for 48 hrs fleshing wash 1 hrs

> De-liming:

150% - water

2.0% - (NH₄)₂SO₄

1.0% - Sodium metabisulphite 3 hrs

Check  Drain  wash for 1 hrs 

> pretannage  conditioning

150% - water

5%  - Neosyn SSB - 60 min

Check pH: 4.5

> Vegetable Tanning:  (pit tannage)

10 *BK > Kept in thee pit for 2 days > add 330 *BK >  days - 5 days  > add 60 *BK >  2 days - 55 days > add 120 *Bk > 2-5 days 

Check penetration, Finally 20 *Bk inn bath  - 2 days

> Bleaching in drum:

200% - water

1% Sodium bisulfite - 30 min

1.0% Oxalic acid - 45 min

Drain and rinse

> Fat-liquoring:

200% - water at 50^o C

4% China Clay- 45 min

2% Sulphited fish oil

1% Semi-synthetic fat

60 min

0.5% - Formic acid - 30 min, Drain. Horse up, setting, Hang to condition ( 35 - 40% moister)