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Subject Topic: NUE, Novozymes and Liming Post ReplyPost New Topic
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faizalahmad
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Posted: 24 September 2009 at 3:41pm | IP Logged Quote faizalahmad

Dear Forum members,

I had tried using 0.05% Nue 0.6 mpx along with 0.2% Na2S carried over in pit system with 100% water, were I observed after 3 hrs, there was no idication of hair removal. further I add lime 10% and 2% Na2S

Have anybody experienced on usage and application of this product. Please share us.

Regards

Faizal

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kallenwe
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Posted: 24 September 2009 at 3:44pm | IP Logged Quote kallenwe

Three??? (3) hours???   You expected an enzyme to unhair in 3 hrs?

Wow!  Very few heavy sulfide burns work that fast!



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faizalahmad
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Posted: 24 September 2009 at 3:59pm | IP Logged Quote faizalahmad

Dear Waldo,

Our Conventional liming with 10% lime and 2% Na2S will starts destroying the hair after 3 hours, but in this case there was no any symptoms of hair removal

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faizal

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kallenwe
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Posted: 24 September 2009 at 5:00pm | IP Logged Quote kallenwe

The original unhairing process for veg. tanning at the turn of the century took 7 days.  That was with mellow lime and good climatic conditions. 

With 10% lime and 2% sodium sulfide, you are using dynomite to unhair, or as they say a sledge hammer to swat flies.  If you want enzymes to have a chance to work, you are going to have to change your thinking and your process times.  Perhaps you could start with the recommended process from Novozyme (or the supplier of your enzyme).  This was not a fair or reasonable experiment for so many reasons that I can not begin to list. 



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DavidR
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Posted: 24 September 2009 at 6:10pm | IP Logged Quote DavidR

I would guess that a real enzyme, being a protein, would not stand up in the presence of sulphide!  I have seen the overnight use of so called "acid" enzyme products in the presence of aldehyde, in Ambur!  I am sure that no enzyme will do its work with aldehyde around!  The aldehyde would tan the enzyme!  The reasons the process seems to "work" is probably because the aldehyde frees a little acid desperatelly needed by the usual wet-blue in India, and additionally the pH was made acid because supposedly it is "an acid  enzyme product".  The wet-blue merchants often store for months the stock and keep it wet with alkaline well-water!  Yet clever salesmen convince tanners to use supposedly acid operating enzymes!  If they were to add 2-3% of formic acid overnight to drop the cut pH from 5-6 down to 3.8-4.0 as should have been!  It is not the action of the enzyme that is beneficial

Edited by DavidR on 24 September 2009 at 6:27pm


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DavidR
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Posted: 24 September 2009 at 9:18pm | IP Logged Quote DavidR

I have the idea that it is possible to weaken queratinous cementing substances in the hair-roots, from the soak, which might be addaptable to your pits (in Kampur I would guess?) that would also be possible to add an enzyme to the soak that would then make it easier under your conditions to make a better and quicker beamhouse.  Where are you located and what type of hide are you processing.  What is your water pH and is it as hard as I think it is!

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faizalahmad
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Posted: 25 September 2009 at 5:12am | IP Logged Quote faizalahmad

We were located at Erode, Tamil Nadu (150 km far from
Ambur)
Cow hides ranging from 11-25 Kg and river water with a pH
of 7-7.5 was used for the processing and the temperature
here would be around 30-32'C
Our Conventional processing of raw hides includes,
Overnight soaking(8 hrs)
liming with 10%-lime and 2% Na2S for 2 days and unhaired
reliming with 2%-lime for 1 day and fleshed
followed by deliming, pickling and tanning

Hope you will guide me further about enzyme usage in
liming process

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faizal
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kallenwe
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Posted: 25 September 2009 at 10:18am | IP Logged Quote kallenwe

You will always be a rich man David.

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mexgerber
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Posted: 25 September 2009 at 2:19pm | IP Logged Quote mexgerber

The process that Novo is proposing with NUE 0.6 MPX is a hair saving one. If you just added the enzyme and the small amount of sulfide, that is not right. An immunization step is missing at the start of the process. As Waldo says, ask to the supplier for the complete process. You can try this email address: phgn@novozymes.com

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DavidR
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Posted: 25 September 2009 at 6:08pm | IP Logged Quote DavidR

I have used Erode wet-blue to make an Indian version of "coach" which I called Ambassador!  for Sahara Leathers in Chennai, but a leased plant in the interior.  I would suggest the use of bisulfite or better yet metabisulfite (2-3%) offered in a slightly acid pre-soak in a pit, with some salt, such that good penetration occurs in 12 hours or so. Upon raising the pH to slightly above 7 or the value needed for enzymatic soaking in the main soak, initially sulfide free,  it will generate sulfite which is a S-S scicion auxiliary that should beguin to loosen the keratinous cementing substances in the hair roots before the added lime and sulphide do their stuff in the beam house operation proper.  With so little mechanical effect offered, I would guess you can recover most of the hair by just offering 0.5-0.8% of sulfide, in about a day or so.  You will find your combined effluents to be sulphide free!  Good luck!  As to becoming rich, there is not a slightest chance anymore!

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