Proviera’s leather products deliver performance as good as the best of chemicals / enzymes even while offering flexibility in application (can be applied at wide pH and temperature range) and have long shelf life (exceeding 12 months from manufacturing date). Proviera  range of tannery products are fully biodegradable, REACH certified containing  a powerful consortium of biochemicals derived from probiotics.

basictanneryprocess

Influences on Application Rates of Proviera Tannery Products

Raw hides and skins vary in animal type (bovine, sheep, pig, etc) and across breeds, fat content (prefleshing-mechanical removal of fat from raw hide, different animal types have different levels of natural fat and other characteristics), origin (temperature is the largest indicator for fat content-the colder the more fat, diets vary, species) method of preservation (salted, sun dried, chemical preservatives, raw) as well as cleanliness (raw hides are covered in blood, dung, dirt, etc).  Raw hides vary by region.  A salted, bovine hide from North America has different characteristics than a South American salted, bovine hide.  Each of these raw hide characteristics influences the application rate of Proviera’s tannery products.

In addition to raw hide characteristics each tannery will follow a unique process to produce their desired leather.  This includes: brand of chemicals used in each stage, quantity of chemicals used in each stage, process time in each stage, machinery used (drums vs paddles), speed of drum rotations at each stage, water saving methods, mechanical actions, sophistication level of the tannery (fully automated or man power),  environmental regulations will vary in each country (sometimes within the same country),  hair saving methods or dissolved hair systems, type of tanning (chrome vs vegetable), presence of a wastewater treatment plant, climate, etc.  Each of these processing characteristics influences the application rate of Proviera’s tannery products.

Beamhouse and Tanyard

Biocides
Biocides prevent the growth of bacteria which can damage the hides or skins during the soaking process
Surfactants-Replaced with ProSoak/ProSpread
Surfactants are used to help with the wetting back of the hides or skins
Degreasers –Replaced with ProDegreaze
Degreasers help with the removal of natural fats and greases from the hides or skins
Swell regulating agents
Swell regulating agents help prevent uneven swelling of the hides or skins during liming
Lime
Lime is used to swell the hides or skins
Sodium Sulfide –Reduced by up to 30%
Sodium Sulfide chemically destroys the hair on hides or skins
Sodium Hydrosulfide –Reduced by up to 30%
Sodium Hydrosulfide chemically destroys the hair on hides or skins. It does not create as much swelling as Sodium Sulfide
Caustic Soda
Caustic Soda is used during the liming process to help swell the hides or skins
Soda Ash
Soda Ash is used during the soaking or liming processes to help raise the pH of the hides or skins
Ammonium Sulfate
Ammonium Sulfate is used during the deliming process and helps remove lime from the hides or skins
Ammonium Chloride
Ammonium Chloride is used during the deliming process and helps remove lime from the hides or skins
Sodium Metabisulfite
Sodium Metabisulfite is used during the deliming process and helps prevent the formation of toxic Hydrogen Sulfide gas during deliming. It also acts as a bleaching agent
Formic Acid
Formic Acid is used during the pickling process to lower the pH of the hides or skins
Sulfuric Acid
Sulfuric Acid is used during the pickling process to lower the pH of the hides or skins
Salt
Salt is used during the pickling process to prevent acid swelling of the hides or skins
Sodium Formate
Sodium Formate is used during the tanning process to assist with the penetration of chromium tanning salts into the hides or skins
Chromium Sulfate
Chromium Sulfate is the tanning agent used to make wet blue
Aldehyde Tanning Agents
Aldehydes are tanning agents used to make wet white
Magnesium Oxide
Magnesium Oxide is used during basification and raises the pH of the hide or skin to allow the Chromium or Aldehyde to chemically bind to the skin protein
Fungicide
Fungicides are chemicals that are used to prevent the growth of moulds or fungi on tanned hides or skins

Dyehouse

Surfactants / Wetting agents-replaced with ProSpread
Surfactants help in the wetting back of the wet blue in the dyehouse
Degreasers-replaced with ProDegreaze
Degreasers help remove grease or fats that may be present on the wet blue as a result of the wet blue coming into contact with machinery
Sodium Formate
Sodium Formate helps raise the pH during the neutralization process
Sodium Bicarbonate
Sodium Bicarbonate helps raise the pH during the neutralization process
Formic Acid
Formic Acid reduces the pH for the rechroming process or helps with chemically fixing dyehouse chemicals to the leather at the end of the dyehouse processes
Chrome Syntans
Chrome Syntans are used during rechroming to improve the softness of the final leather
Chromium Sulfate
Chromium Sulfate is used during rechroming to improve the softness of the final leather
Syntans
Syntans are used to give properties such as softness, fullness, roundness to the leather
Resins
Resins are used to give fullness and a tight grain to the leather
Polymers
Polymers are used to give fullness and a tight grain to the leather
Dyes
Dyes are used to give the leather a color desired by the customer
Dyeing auxiliaries-replaced with ProSpread
Dyeing auxiliaries help disperse the dyes evenly
Fatliquors
Fatliquors are oils that are added to leather to give softness to the final leather

Finishing –ProSafe used to emulsify finishing mixes

Acrylic Resins
Acrylic Resins give specific properties to the leather finish such as adhesion, water resistance
Butadiene Resins
Butadiene Resins give specific properties to the leather finish such as good coverage
Polyurethane Resins
Polyurethane Resins give specific properties to the leather finish such as good toughness and good lightfastness
Fillers
Fillers help fill small blemishes on the leather surface
Dullers
Dullers help reduce the gloss of the finish
Crosslinkers
Crosslinkers are used to toughen the leather finish and improve the water resistance properties of polyurethanes
Handle Modifiers
Handle Modifiers are used to give the leather surface a waxy or slippery feel
Nitrocellulose Lacquers
Nitrocellulose Lacquers are used in the top coat of a leather finish
Acrylic Lacquers
Acrylic Lacquers are used in the top coat of a leather finish
Polyurethane Lacquers
Polyurethane Lacquers are used in the top coat of a leather finish
Viscosity Modifiers
Viscosity Modifiers are used to increase the viscosity of a finish mixture
Pigments
Pigments are coloring agents that help hide defects on the leather surface
Dyes
Dyes are coloring agents that are used to slightly change the color of the leather finish or to give the leather finish a more natural look

The diagram below will show that many different toxic chemicals are used before the raw hide turns into the high quality leather. This process will add significantly on effluent load due to use of extensive range of chemicals.

rawhidefullprocess

 

Our formulations for leather industry are the first of its kind globally, substantially improve tannery operations - better than current chemicals used and have several compelling value adds:

Improve tannery operator profits
  • Improves yield due to remarkable opening of structure of leather, flatter leather (fewer wrinkles), uniform color
  • Eliminates need for surfactants
  • Reduces chemical costs
  • Reduces water usage : Reduced water consumption in both wetting back and degreasing operations as our products do not foam
  • Reduces processing time thus saves energy : Increased output as beamhouse processing time up to unhairing can be reduced by up to 50% without any compromise on quality
  • Pricing not driven by crude oil price – more stable pricing
Reduce Pollution

Lower effluent load allowing higher through put where restrictions on effluent discharge exist and eliminate the use of several polluting chemicals

  • Beamhouse:
    • Total COD 107.1 kg O2 per ton of raw hide
    • Total BOD 38.5 kg O2
  • Soaking:
    • COD 23.8 kg O2 per ton
    • BOD 6.7 kg O2
    • This effluent load will be completely eliminated when our products are used at Soaking
    • (Note: For wet salted hides a 75-80% reduction in BOD/COD expected at Soaking)
  • Liming:
    • COD 62.3 kg O2 per ton
    • BOD 24.6 kg O2
    • The COD/BOD here is contributed mainly by lime and sodium sulfide.  We can reduce sodium sulfide by 30%, so we can expect COD to be reduced by 10.0 and BOD by 4.0.
  • OVERALL REDUCTION:
    • COD is expected to be reduced by 32 kg O2 per ton (30% reduction with Proviera Products)
    • BOD is expected to be reduced by 10.0 kg O2 (25% reduction with Proviera Products)
  • About 55% of the pollution load comes from the liming and unhairing stage
    • Proviera has demonstrated a range of reduction in  the use of sodium sulfide (from 15% to 30%) in this step
    • Proviera also demonstrated a ‘hair save process’  on goat and calf skins(up to 100% reduction of sodium sulfide), where it is possible to collect the hair and eliminate dissolved hair going into the effluent
  • The second biggest source of pollution is the soaking step, which is about 15% (mainly because of the salt, but also due to the chemicals used at soaking including chemical bactericides)
  • By using Proviera products for soaking, liming and unhairing steps, we should be able to reduce significant pollution. The quantum of reduction will depend on the current practice in the tannery
Improve quality of leather

Improves leather grade with better surface cleaning; fewer growth and drawn marks; better fixing of chrome and other dyes; brilliant and uniform leather

Operates in broad pH range

Proviera Probiotic products operate in a broad pH range of 2-14, they can be used anywhere in the tanning process.

Other benefits that accrue
  • Effective across wide range of hides and skins
  • Our  products are 100% biodegradable
  • Broad temperature range (5°C to 60°C) and pH range (2-14)
  • Reduced odor levels inside and outside tannery
Application of our products during Tannery Process
Tannery Operation Our Tannery Product
Soaking of raw hide ProSoak + ProSpread
Degreasing (raw hide and wet-blue) ProDegreaze
Wetting and dispersion during tanning ProSpread
Dyeing ProBright
Finishing ProSafe