Beamhouse Technology

Innovative Technology for Leather

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BEAMHOUSE TECHNOLOGY

WG/02

SCHILL+SEILACHER AG
Boeblingen / Germany

Bacteria

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THE PROBLEM
u Immediately after slaughter, bacteria present in the hide start to multiply

INFLUENCING FACTORS
§ § § § § Water Substrate pH Temperature Time

The Putrefaction Process will depend on following factors: § § § § The bacterial flora presentThe degree of contamination The temperature of the hide Time

Innovative Technology for Leather by SCHILL+SEILACHER AG

Bacteria
Evidence of Bacteria action
§ § § § Bad smell Presence of a sweet liquid in the flesh side Hair slip Reddish colour in salted hides (halophilic bacteria )

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Types of Bacteria
§ Halophilic o Growth in presence of high salt concentration o Produce pigmentspink, red or violet on salted hides (“red heat”) Halotolerant o Growth without added salt as well as salt concentrations (>12%)

§

Over 100 genera of bacteria have been isolated from raw hides Only some of them produce collagenase, the enzyme that breaks down collagen

Effect of Bacteria attack on leather
§ § § §

Sueded grain Loss of hides substance (loose and empty) Low tensile strengthProminent veins

Innovative Technology for Leather by SCHILL+SEILACHER AG

Bactericide
HIDE PRESERVATION
As the bacteria starts attacking the hide substance straight after slaughter, action has to be taken as early as possible .

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§ Temperature (short term preservation)
o Cooling with cold water equipment or ice (addition of Bactericide) o Chilling

Temperatures around 2-4 oC willgive protection for 24-48 hours.Mostly used in combination with Bactericides. Hides can now be green fleshed, or transported to the tannery for processing.
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Bacteria Analysis
100 90 80 count cfu/gm 35dC 70 60 50 40 30 20 10 0 1 1.57 2 2.7 0.62 4 5 6 17.9 19.5 3.6 39 31 23.3 7.3 5 1.76 7 1.85 8 9 1.61 10 0.9 0 30 47 66 50 45 40 35 30 25 20 Treated,1%solution 15 10 Untreated

Bacteria counton hides after kill (with and without bactericide treatment)

Hours

§ Dehydration (long term preservation)
o Salting (Brine curing) o In race ways, mixers or drums o Dry salting

Hides can be kept from 6 months up to 12 months. This is the most commonly used of preservation, especially for raw hides export.

Innovative Technology for Leather by SCHILL+SEILACHER AG

Bactericide /Soaking
SOAKING
The use of Bactericides in the soaking is very important. The Bactericide has to be offered from the beginning of the soaking (re-wetting) process, as the bacteria growth rate will increased in a aqueous medium and reach levels when damage will appear. Bactericide from Schill & Seilacher

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VINKOL MK
8 7

Total Bacterial count

6

5

no Bactericde
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Effective level0,10% Vinkol MK

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2

1

0

1

2

3

4

5

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ü.N.

Soaking time in hours.

Bacteria count in the soak with and without Vinkol MK VINKOL MK is a combination of selected biocides. General recommendations for the use of VINKOL MK: SALTED RAW MATERIAL: 0,10 - 0,20 % VINKOL MK duration: Up to one day, depending on the raw material DRIED RAW MATERIAL: Dirt-soak: 0,1 - 0,2 %VINKOL MK duration: over night Main soak: 0,2 - 0,4 % VINKOL MK duration: 2-3 days

Innovative Technology for Leather by SCHILL+SEILACHER AG

Bacteria / Soaking
Bacteria can be made visible within 24 hours DIP SLIDE TEST

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Up to a total count of 104 bacteria per ml no visible grain damage occurs during soaking and liming, 104- 106 medium infection, 106 up heavy infection (grain damage!)SOAKING TRIALS

Bacterial Count Agar per ml Main Soak
start

Dirt soak
(4hrs)

Main Soak
end (20hrs)

No Bacericide

104

103

>107

With VINKOL MK 0.05% dirt soak 0.1% main soak 103 103 103

Innovative Technology for Leather by SCHILL+SEILACHER AG

Enzymes
Introduction: ENZYMES are complex protein structures. ENZYMES are biological catalysts, which accelerate the...