COMMERCIAL EXOTIC LEATHER MANUFACTURE FEATURES AND REQUIREMENTS OF A STATEOFTHEART ALLIGATOR TANNERY - PowerPoint PPT Presentation

Loading...

PPT – COMMERCIAL EXOTIC LEATHER MANUFACTURE FEATURES AND REQUIREMENTS OF A STATEOFTHEART ALLIGATOR TANNERY PowerPoint presentation | free to view - id: b31e-MDBlY



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

COMMERCIAL EXOTIC LEATHER MANUFACTURE FEATURES AND REQUIREMENTS OF A STATEOFTHEART ALLIGATOR TANNERY

Description:

... be rare), holes and scratches or scars that penetrate beyond the surface of ... of appropriate enzymes, and approved biodegradable biocides into the bath. ... – PowerPoint PPT presentation

Number of Views:1810
Avg rating:3.0/5.0
Slides: 76
Provided by: JerryC6
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: COMMERCIAL EXOTIC LEATHER MANUFACTURE FEATURES AND REQUIREMENTS OF A STATEOFTHEART ALLIGATOR TANNERY


1
COMMERCIAL EXOTIC LEATHER MANUFACTURE FEATURES
AND REQUIREMENTS OF A STATE-OF-THE-ART ALLIGATOR
TANNERY
  • David R. Small
  • Consultant and Master Tanner

2
  • INTRODUCTION
  • I suppose you could say that this speaker is an
    historic relic of another era in the United
    States leather industry! About seven years ago, I
    retired from a life-long career in the leather
    industry (with a few minor interruptions) where I
    had applied my Rensselaer Polytechnic Institute
    Chemical Engineering education. In following my
    career I roamed through ten states and Canada
    before being recruited to help start an exotic
    skin tannery in Baton Rouge, Louisiana. My career
    covered all aspects of goatskin, cattle hide,
    cattle whole hide, cattle split, pigskin and
    exotic leather manufacturing for shoe, bag,
    clothing, boot, belt and upholstery applications.
  • My career encompassed an entire era of the US
    tanning industry, and its customers, for that
    matter. I have known most of the leading leather
    scientists, technologists, suppliers and
    businessmen from that period. Unfortunately for
    them, but

3
  • fortunately for me, I have outlived far too many
    of them.And, sadly, I have watched while this
    once large, proud, strong and quite profitable
    small business industry has imploded on itself
    behind me. Major players in the industry have
    disappeared even very recently. None of the
    entities I previously worked for, some relatively
    quite large and prominent, are around today--no
    trace of them can still be found. Somehow weve
    managed to export all but a small scattering of,
    mostly giant, companies, including the bluing
    plants associated with your Texas big packing
    plants, from this once important industry.
  • The Exotic Leather Industry I Know
  • From the viewpoint of an experienced engineer,
    I will now attempt to present you with my
    personal, somewhat idealized, response to the
    question posed to me of whether or not I believed
    it would be feasible to develop and operate an

4
  • exotic tannery in Texas, possibly somewhere in
    this general vicinity.
  • Lets just get something straight at the
    outset. If someone is considering the feasibility
    of starting new exotic tanning facilities here or
    anywhere else, from experience I can tell you
    this is a big undertaking. The days of the small,
    family run bucket-shop reptile tanneries that
    used to be clustered around the New York City
    area are long gone. No longer is a
    practical-trained old tanner going around in his
    high boots with his secret formula book tucked in
    his back pocket, sleeping beside the paddle at
    night and making sure no one watches as he makes
    his secret chemical feeds. The perishable,
    straight vegetable-tanned, stiff-as-a-board,
    cracky alligator leather made back then is also
    only an old memory. This big undertaking isnt
    inexpensive either. It is truly capital

5
  • intensive. Make no mistake about it. Doable,
    yes, but not easy or cheap. It had better be done
    correctly from the beginning if it is to
    succeed--simply a matter of good practice
    combined with good sense. I will provide lots of
    reasons to back up the statement that a good
    exotic leather tannery is a costly project.
  • What follows are my personal opinions of what
    it would take to establish a long run
    sustainable, modern exotic leather tannery. I
    suppose it is possible to cut corners to reduce
    the initial capital requirements. People have
    created small-scale tanneries with minimum
    investment. But to really establish something
    capable of competing with the existing large
    foreign manufacturers, my philosophy is that
    making the larger initial investment and
    commitment is the only safe route to long-term
    success--high volume, high quality output,
    efficiency, optimal operating costs and long term

6
  • profitability. I will propose for you now,
    requirements for a facility whose owners could
    boast about and be confident of and proud to show
    off to their customers and community both the
    plant and the top quality products it produces.
    Exotic leather making today is more science and
    engineering than art and should be approached as
    big time or not attempted at all. Here is how I
    intend to approach the subject
  • Starting with some remarks about the project as a
    business
  • I will proceed to talk about the physical plant
    and what it needs to contain
  • A few words about staffing
  • The raw material
  • Some equipment comments
  • Discussion of the major special steps and
    critical components of actual exotic leather
    making

7
  • Finally, some remarks and opinions about
    marketing and business prospects
  • FEATURES AND REQUIREMENTS OF AN ALLIGATOR
  • LEATHER TANNERY
  • Business Plan
  • First of all it is a business. That means it
    requires the same thoughtful advance preparation
    that any business does. A detailed
    well-researched, all-inclusive and documented
    business plan has to be completed before anything
    else is done. The plan should cover all the bases
    including capital requirements, key employees,
    marketing plan, site selection, facilities
    design, operating cost and cash flow projections,
    etc. The plan has to be realistic and provide for
    worst case as well as best case scenarios. Only
    when a complete business plan has been written
    and analyzed and extensively challenged

8
  • and proven viable, should an entrepreneur or
    entrepreneurial group consider proceeding with
    such a project to the next step of raising
    adequate necessary capital.
  • The Physical Plant
  • The site should be both accessible for trucking
    traffic and isolated from other facilities.
    Structures should be sturdily built and easy to
    maintain. They should be planned with sufficient
    interior space and utilities to provide room not
    only for relatively small starting production,
    but plenty of room for future expansion needs. It
    is much easier to plan for eventual growth than
    to try to squeeze more production into an already
    filled area.
  • Ample, even abundant fresh water availability
    is a given, of course. In a hot climate location
    such as here in Texas, if the incoming supply
    water temperature is elevated during the

9
  • hot months, a water cooling arrangement is
    highly advisable. And of equal importance at the
    other end of the water flow circuit, is some kind
    of effluent-accepting and treating system to take
    the process waste stream that will be generated
    and prepare it for discharge to a (POTW) or the
    environment. The site itself should be large
    enough to accommodate whatever effluent storage,
    equalization and on-site pretreatment plant is
    called for.
  • At least primary or secondary effluent
    treatment systems will be necessary. Their design
    and operating cost has to be incorporated into
    the plan. Efficiency in process design and
    control (recycling and optimal flow rates etc.)
    will contribute to minimizing costs of the waste
    treating system design, installation and
    operation. The design will need permitting and
    approval by the district and state authorities.
    All this should be in the hands of a good
    consulting engineer

10
  • or engineering firm. Realistic estimates of
    these engineering costs must be part of the
    business plan.
  • Chemicals and equipment used in any tannery
    present plenty of hazards, so it is necessary to
    have a complete safety plan that complies with
    OSHA and local regulations from the outset. That
    includes piping and drains designed to segregate
    low and high pH streams to prevent toxic gas
    (I.E. H2S, SO2, Cl2, etc.) generation and
    emission. Much preferable to have the engineers
    do this in the planning stages than have to retro
    fit them into your facilities afterwards (or to
    experience terrible accidents as have happened in
    tanneries in the past where improper attention
    was given to these details!).
  • Exhaust systems of suitable capacity for
    ventilation, finishing spray booth vapors and
    possible toxic gas removal, are necessary. The
    exhaust system will itself need to comply

11
  • with VOC and EPA or DEQ toxic emission
    standards. This is just another reason why such
    plants need to be in isolated locations. What I
    have addressed so far applies to almost any
    tannery, not only exotic plants.
  • Exotics Plant Specifics
  • Now Id like to discuss some of the specific
    needs of an exotic, particularly alligator and
    ostrich skin, tanning facility.
  • Receiving Area
  • The first part of the plant has to have a
    suitable place where the salt-cured or green
    skins are received. It can be outdoors, but under
    sufficient strong cover to protect the area from
    the elements. Indoor space is preferable.
    Forklift access is necessary, here. Provision for
    counting, inspecting, examining, measuring and
    recording tag numbers for the arriving skins is
    important. The area needs good lighting and
    airflow.

12
  • Inspecting Area
  • A sturdy inspection table with a glass top back
    lighted from underneath and etched or painted
    with cross hatching by inches and centimeters can
    easily be built to be used for Checking incoming
    shipments and avoid disputes with shippers. Large
    quantities of curing salt accumulate at the
    receiving table. Since salt is such a difficult
    contaminant to remove from any effluent,
    provisions have to be made to collect as much of
    it as possible for separate disposal while still
    in the solid condition.
  • Hot Water Production
  • The plant will need a modern, maximum efficient,
    recirculating hot water heating system of which
    there are several excellent direct gas-heated
    models available. Piping throughout the plant is
    critical. Design pipe line installation

13
  • to protect against incoming water freezing in
    winter or heating in summer. It is also important
    to avoid any possibility of backup from hot water
    supply lines into any cold water lines. To insure
    this, design proper check values and double
    shutoff value systems into the piping.
  • Beamhouse Solids Collection/Processing
  • In the beamhouse area of an exotic tannery,
    considerable amounts of low-density solids are
    generated and deposited into the effluent stream.
    An efficient, mechanical filter system to
    separate and collect these solids and remove them
    from the effluent stream before it enters the
    waste treatment plant is another important
    component By reducing sludge entering the
    treatment system, this will both simplify
    disposal of the solids and allow the treatment
    system to operate at maximum efficiency. The
    outer protective keratin layer of exotics, of

14
  • course, is in the form of scales and quills, not
    hair, as in other leather making substrates.
  • Pitched Floors
  • Floors need to be pitched away from process
    vessels toward some form of drainage ditches
    which, in turn, need to slope toward a large sump
    collector outside the building, from which the
    effluent can be pumped to the treatment system.
    The ditches need to be adequately sized for
    maximum anticipated flow out of the processes and
    equipped with covers able to support forklift
    traffic. Floors need acid-and alkali-chemical
    resistant surfaces along with plenty of toughness
    for forklift and other wheeled equipment traffic.
    Installation of one of the many available modern
    flooring surface treatments with these properties
    during original construction will pay off in the
    long run built-in surface flushing lines to
    maintain sanitation and

15
  • cleanliness go into the starting construction.
  • Wet End Processing Areas
  • With the basics of the facility now in place, we
    can address some details of the separate
    operating areas that it should contain.
    Obviously, a wet department for the essential
    processing has to occupy a sizeable portion of
    the structure. First an area needs to be provided
    where workers can clip skins, count, record
    tags and weigh them into predetermined
    formulation batches for processing. It is
    desirable to arrange a segregated area for each
    of the wet departments the beamhouse, pickle and
    tan section, and retan and coloring area.
    Although it is possible to do pickling, tanning
    and coloring in the same vessel, it is much
    preferable for quality control as well as
    equipment scheduling and maintenance to have
    separate reactors dedicated to retanning and
    coloring. At

16
  • the start of a facility, a minimum of full sized
    processing vessels will suffice. However ample
    floor space should be designed for plenty of
    additional units when production demands
    eventually grow. This is much preferable to
    having to squeeze extra vessels in when they are
    needed.
  • In-Process Holding Area(s)
  • A generous space nearby the production
    processing vessels, using the same drains, needs
    to be set aside for a pilot plant with
    various-sized miniature vessels to do process and
    product development, color matching and small
    order processing. To attain and retain the high
    quality standards always required by the end
    users, and to develop interesting new products to
    retain market interest, it is important to have
    continuous product development work on a pilot
    scale.

17
  • Chrome Liquor Capture
  • Advance provision for capturing spent chrome
    liquors (yes, at least partial chrome tanning is
    pretty standard for producing quality exotics
    today), before they can mix with any other spent
    streams, will allow for chrome recycling or
    chrome recovery techniques. However, that would
    not preclude designing the tanning process itself
    for maximum chrome exhaust.
  • Mezzanine Level Access
  • A mezzanine above the process vessels,
    accessible to forklifts, is not mandatory, but it
    is a great help for preparing and batching,
    weighing and making formulation chemical feeds. A
    storage area where liquid and solid chemicals can
    stay dry, be received and kept separate is a
    must. Hazardous materials should be isolated from

18
  • non-hazardous, of course, in a separate section.
    Simple cleanup of that area should be built in.
  • Drainage
  • Generous drain-connected holding spaces for
    storage where goods in process can drain excess
    liquors while reaching equilibrium between
    operations are needed.
  • Process Analytical Lab
  • Convenient to the wet departments, at least a
    minimal lab for process controls (pH, Be/, etc.)
    is a must. In a separate part of that area,
    dyestuffs and samples of chemicals can be kept
    and precision weighed or measured. Somewhere
    close to the coloring vessels a very well lighted
    area, with modern daylight color-corrected lamps
    and a modern color-matching booth large enough
    for display of whole skins, is required. It
    should have a small dryer set up close by for

19
  • process sample checking for coloring, finishing
    and ready to ship color matching.
  • Moisture and Dust Control Measures
  • Mechanical operations such as fleshing, shaving
    and buffing require their own closed off space
    with ample air circulation and provisions for
    gathering and removing the solids generated by
    the operations. Effective shaving and buffing
    dust collection is extremely important. The dust
    must not be able to escape from the area where
    they are created. You cant have dust floating
    around finishing department of a quality
    producing exotic plant any more than in a
    conventional tannery. Dust particles are
    particularly destructive to glazing. Drying
    technique makes a major contributor to exotic
    leather quality. There are numerous approaches to
    accomplish good drying. Plenty of space

20
  • has to be allocated to drying space. There are
    likely to be at least three separate dryings
    during the course of exotic processing--crust,
    color, finishing.
  • During drying before finishing, the skins
    should always be in a stretched condition.
    Something as basic as manually tacking out the
    skins onto plywood (usually done today with heavy
    duty staple guns, using only stapes that will not
    react with and stain the wet skins), and leaving
    the boards stacked in a loft until drying is
    uniform and complete, works well. But it is very
    labor intensive. More recent automated toggling
    or vacuum drying devices can also be used. They
    cost a great deal more, but for eventual higher
    volume production capability they should be
    carefully considered with space allowed for them.
    Whatever is the method of choice for stretching
    the skins, the uniform circulation of low
    temperature (not much above ambient), low
    humidity,

21
  • turbulent air in the system is critical to the
    result. Low temperature, low humidity conditions
    are what produce the slow uniform drying
    necessary to prevent shrinking and produce
    desired soft leather out of the dryer. Drying is
    of key importance so each tanner should very
    carefully evaluate it during planning. A space
    requirement that might be overlooked is a nice
    clean area for conditioning crust skins after
    drying. A slightly raised platform to provide air
    circulation from all around the piled skins is
    ideal. Enclosing the crust area with a protective
    curtain sort of like a hospital bed arrangement
    would be a plus. Drying after finish coatings can
    be done without stretching. If some kind of spray
    machine is installed (any consistent high-volume
    quality producer ought to have at least one
    single-stage unit), its conveyor will be
    connected to a dryer of one type or

22
  • another. There again the drying should be slow
    and air circulation needs to be emphasized over
    higher temperatures. Finish coatings on exotics
    are very thin coatings that will dry relatively
    quickly if exposed to high volumes of only mildly
    warmed air. Keeping the humidity down is still
    very important. Good exhaust with proper
    filtration and scrubbing to prevent vapors going
    into the atmosphere will have to be demonstrated
    before a plant can get permitted. Water-washed
    booths are expensive, but, if well designed, can
    help prevent lost of exit air quality problems.
  • Finish Application and Final Drying
  • A hand booth can also be used for applying the
    finish coatings. The same exhaust requirements
    apply here. Hand spraying is difficult to control
    for complete uniformity and requires a skilled
    operator, is tiring and slow from a

23
  • production viewpoint, but it does contribute
    some of that hand-crafted look to the final
    product. Hand sprayed finished skins can be
    simply hung up between coats and left to dry with
    good air circulation. The dryer can be as
    elementary as a series of stretched close-lines.
    Obviously that is quite crude, and cheap but it
    works. It consumes considerable floor space. A
    much preferable arrangement employs some kind of
    a moving chain stick dryer arrangement where the
    conveyorized slow-moving sticks pass through an
    enclosed heated tunnel dryer before returning to
    the spray booth ready for the next spray coat.
  • One area that, for obvious reasons, has to have
    cleaner air and surroundings than any other place
    in the plant is the glazing room. Design should
    anticipate those conditions along with plenty of
    room for the piled skins ready for

24
  • glazing into so-called classic alligator
    leather.
  • Dry milling is used with exotics just as with
    conventional leathers, so a really dry space
    where the skins can easily be loaded into the
    unloaded from the mills is another requirement.
    Here again, a forklift accessible mezzanine from
    which the skins can be loaded into the dry mills
    is nice to have.
  • Mechanical/Maintenance Shop
  • Last, but by no means least, is the need for a
    maintenance shop where equipment for keeping the
    plant and its contents in good condition can be
    kept and used. It may not be practical because of
    low volume usage and high cost, but it would be
    great to have facilities for reblading the
    various cylinders used in the different machines.
    Special sized cylinders with different space
    between blades and different

25
  • blading angles are required for exotics and it
    can be a problem constantly having to send them
    to outside contractors for reblading and waiting
    for their return.
  • Shipping Area
  • All the work of the plant culminates in the
    shipping room. This requires a spacious, well lit
    (some natural light is preferable, the artificial
    lighting should be color corrected), clean, dry
    area. It will need provisions for final grading,
    color checking against standards, smooth-topped
    tables for alligator measurement, tag recording
    and packing equipment. For the larger skins of
    Ostrich, including space for a simple modern
    measuring machine on which skins can be fully
    extended, is not just a very good idea, it is a
    necessity.
  • Security and Worker Conveniences
  • It is important not to overlook provisions for a
    plant security

26
  • system that will protect against the various
    specific hazards that are inherent in exotic
    processing in addition to the usual problems from
    fire, theft, sprinkler failure, excess interior
    temperature either high or low, hazardous gas
    emissions, etc. Having motivated good employees
    is vital. Their needs should be built into the
    plant in the form of ample wash and rest rooms,
    dressing and showering areas and a well
    ventilated eating area. Provisions for both
    genders and the handicapped will pay off and
    round out a proper facility (and, most likely, be
    required for permitting).
  • That pretty much covers the physical plant. I
    have tried to include lots of very practical
    details that only experience makes one aware of.
    My pointing them out in advance to anyone
    contemplating this kind of venture will help save
    them from lots of later grief, if they heed my
    advice.

27
  • Staffing, Personnel and Job Responsibilities
  • Now let me say a little about staffing. What I
    have given you so far is a picture of a complex
    operation. It needs some good people to handle
    all the details. Responsibilities should be
    divided among several trained individuals.
  • Owner/Principal
  • The principal entrepreneur carries overall
    responsibility and authority, of course, but that
    person should not attempt to be expert in
    everything. He needs to hire some good key people
    and hold them responsible for performance in
    their assigned part of the operation. Although it
    is good for the entrepreneur to have at least
    some understanding of the various special
    details, micro managing does not work very well!
    Responsibility for managing completion of all
    the preliminaries of planning, financing,
    constructing and

28
  • equipping the facility belong to the
    entrepreneur. Also, normally, he or she will be
    responsible for
  • the negotiations for purchasing skins
  • establishing market connections
  • pricing of the products
  • setting compensation and benefits
  • banking
  • community relation
  • approving contracts
  • partners or Board of Directors and stockholder
    and investor relationships
  • overall financial arrangements including
    necessary borrowing for the business

29
  • Plant Manager/Tanner/Leather Engineer
  • Second in command is the plant manager/ tanner
    /leather engineer who is responsible for running
    day to day operations and production as well as
    making the product, while the operation is
    growing. When and if the operation grows to a
    size that warrants it, this function should be
    subdivided to production and process. (When and
    if the size of the operation warrants, a colorist
    and finisher can be added to work under the
    tanners supervision.) The position calls for
    someone with thorough knowledge, understanding
    and experience of tanning and tannery operations
    from raw material to finished product. Leather
    know-how is very important. In addition, the
    person selected needs a chemistry or chemical
    engineering education. If not in the US, people
    with all the

30
  • needed qualifications have been educated and
    should be available in other countries--Mexico,
    Canada, England, Italy, Spain, France, Germany
    and Japan are among the potential sources.
  • Ideally, the person would be experienced with
    exotics, but that specialization can be acquired
    by the right individual as long as there is a
    solid grounding in all aspects of tanning
    including everything from raw material to
    finished product. This position will be
    responsible for training of workers in the plant
    in the various process operation requirements. It
    would be very helpful if he or she has good
    mechanical skills. However, another individual
    will be responsible for the mechanical
    operations. (Notice all along that I try to avoid
    use of the male pronoun because there are women
    today with equal qualifications for all these
    positions.)

31
  • All processes, formulation writing, scheduling,
    record keeping, ingredient specification and
    purchasing, quality and process controls, problem
    solving, product development, color matching, lab
    work, standards, equipment selection etc. will
    originate at this desk. Because so much of the
    potential success or failure of the project will
    depend on this position, great care is needed in
    choosing the right person. Overall compensation
    package has to be competitive and sufficient to
    assure that the future of the operation will be
    in the hands of someone who can be trusted to do
    the job properly.
  • Plant Mechanical Engineer
  • The third key person handles the mechanical
    processes and the plant machinery. When the
    operation is small this person should be
    qualified to set up and run the various
    mechanical operations and also maintain the plant
    equipment. If it is

32
  • only possible to find someone with all-inclusive
    general maintenance know-how, that is the more
    important skill for the position. The best thing
    is for the mechanical person to be fully
    qualified to setup, wire and maintain the
    machines and operate them during the low
    production start-up period. Actual machine
    operation can be taught to good hands workers
    by outside consultants well enough so that the
    selected workers will develop production skill
    for running the machines. This key person will be
    on board early to help supervise the construction
    then place and install all the equipment. Once
    the plant is operational, this person will
    supervise machine production and operators,
    conduct preventative maintenance, and do whatever
    repairs are required over time (or arrange for
    outside assistance when necessary).

33
  • Administrative Assistant
  • As in any other operation, a versatile office
    person will be key to proper record keeping,
    computer functions, reception etc. The office
    person will perform the essential duties of
    comptroller plus record keeping, communications,
    billing and payroll. This position will be
    responsible for liaison with the obligatory
    outside CPA firm.
  • Little-known Ingredients for Success of the
    Exotic Leather
  • Tannery Raw Materials and Marketing
  • Raw Materials
  • Today, a significant sized exotic tannery will
    principally process raw material raised on farms
    or ranches. That is the only way to plan stable
    production, be able to supply orders in a
    dependable way, and be assured of controlled good
    quality input. All my discussions today are based
    on that

34
  • kind of raw material. Supplies are not always
    uniform throughout the year, but with good
    planning and sufficient capital available to take
    advantage of best markets, raw material can be
    stockpiled. This is a main reason why large
    well-designed cooler space is required.
  • Stock that is properly cured and PROPERLY
    stored can be held long enough to smooth out the
    seasonal ups and downs of supplies from the
    farms. Larger cooler space makes it easier to get
    at the oldest raw material so that production can
    be on a first in, first out basis to minimize
    storage time. Larger skins from annual wild
    hunting or nuisance animal kills can be worked
    into production schedules as fillers. They will
    not be the main production as a general rule.
  • There are specific characteristics of the
    exotics--

35
  • alligators, ostrich, lizards and snakes--that
    distinguish them from the more conventional
    bovine, sheep, goat and pig species. The outer
    keratin protein layer (which on other animals is
    in the form of hair) occurs as claws, quills and
    scales. That, plus their irregular shapes and the
    bony horn layers of alligators dictate the needs
    for special handling and equipment in exotic
    processing.
  • As far as shape goes, gators taper down to
    quite narrow width in the tail and the legs
    attach in a way that does not allow them to lie
    completely flat. This makes it tricky when it
    comes to fleshing and shaving. Some foreign
    processors cut the legs off completely making
    handling easier, but doing that removes some very
    attractive leather from the skin and every part
    eventually has to be fully utilized. Alligators
    require very narrow cylinders and cylinder
    blading. Much care is needed to avoid nicks and
    cuts and

36
  • make it possible for the operator to get into
    all the nooks and crannies. Multiple passes by a
    skilled operator using foot control against a
    narrow cylinder seem to be the only approach for
    handling this properly. With larger, thus
    thicker, skins from the controlled annual wild
    animal hunts, a somewhat wider cylinder can be
    used, but splitting is not practical for reducing
    the thickness to proper levels.Here there is a
    big difference from handling larger stock like
    cattle hide on large automatic shavers and
    splitters. Ostrich has to be handled so that the
    quill shaftways do not open into holes. Quill
    sites should end up raised and prominent to
    produce the characteristic ostrich look, but they
    cannot open up raised and prominent to produce
    the characteristic ostrich look, but they cannot
    open up into holes that light can pass through as
    with lace curtains.

37
  • But once the above differences are compensated
    for, the leather-making components consist of the
    same collagen protein that reacts to the basic
    tanning chemistry other leather making substrates
    do. Thus, in my opinion, the real secret of
    tanning good exotics lies in the application of
    good standard leather making chemistry. Incoming
    raw material, unlike cattle hide, has to be
    carefully checked in, measured, inspected and
    registered piece by piece. This is particularly
    so of alligators which are a carefully controlled
    wild species. Tag numbers have to be checked off
    against incoming manifests. The tags must remain
    on the skins and have to be accounted for all the
    way through to shipment. Any tags that break off
    during processing must be fully accounted for in
    the shipping room. That presents many challenges
    along the way as can readily be imagined.

38
  • All ostrich are raised on small family farms or
    very large ranches today. The bulk of commercial
    gators are farm-raised. Gators are harvested at a
    size range of between 3.5 and 6 to 7 feet tops
    (usually closer to 5 feet tops) in length. This
    is the economic point for harvesting, as the
    growth rate declines very sharply after this size
    has been reached. If I recall correctly, this
    corresponds to about 18 to 24 months in age. They
    are traded on the basis of price per foot in
    length, and sold by maximum width measurement in
    centimeters, so there is a premium on width to
    length ratio which varies by the husbandry
    methods of different farmers. That ratio often
    dictates which suppliers are preferred sources.
  • Marketing Strategies
  • This seems to be a good place for a marketing
    aside. Size and orientation of the hide are key
    to marketability of

39
  • the resulting leather. One must pay particular
    attention to these parameters when accepting and
    specifying raw stock.
  • Originally, before gator farming, when all
    skins came from the wild, there was no uniformity
    of size and most skins were much larger than from
    todays farm-raised animals. It took sometime for
    the buyers to accept the smaller range of skin
    size because patterns were based on much greater
    cutting area. However, first of all, the skins
    from the wild had lots of grain damage from their
    natural living conditions, fighting, scratching
    against objects etc. Farmed skins are normally
    almost free of those defects. Secondly, the tile
    size grows with the animal. So the wild skins
    have quite large tiles. In any given cut panel,
    there is much less tile pattern showing than for
    the same panel cut from smaller skins where the
    tiles are much smaller and much more numerous
    within the same area.

40
  • Sometimes in a completed belt made from large
    skins, for instance, all that is visible from the
    tile pattern is a few vertical lines. This little
    key fob that I carry is a good example to
    illustrate the point. It would be easy to cut a
    complete piece of this size from the center of a
    single tile of a large animal. No pattern at all
    would show. It would appear just like a piece of
    leather from an unidentifiable source. Once the
    cutters recognized that small skins resulted in a
    prettier and more interesting look where it was
    much easier to recognize the source in the
    finished product, the smaller, cleaner skins
    became the norm. Some skins may be received green
    (not cured) if a farm happens to be really close,
    but by and large they need to be fully cured with
    NaCl. Pretty much standardized today is shipment
    in boxes with raw gator skins rolled grain side
    out. Excess salt has to

41
  • be shaken off before inspection. That salt needs
    to be collected for disposal or reuse (if it is
    clean enough). Of great importance in both types
    of skins is the takeoff. Only an absolute minimum
    of flesh (adipose tissue) is acceptable in both
    cases. However, there is a fine line to be drawn
    here, because it is possible to damage inherent
    fiber strength if the takeoff goes too deep
    beyond cleaning the adipose tissue from the flesh
    side.
  • Well-presented stock has clean, almost pure
    white backs with little or no hanging yellowish
    pieces of flesh present, no knife cuts and little
    or no odor. The black or brown and white
    variegated coloration of the tiles actually looks
    quite attractive in the raw state when the boxes
    are opened. That coloration disappears during
    standard processing, although a completely
    different product still showing much of it is
    possible with

42
  • substantial changes. I will not attempt to
    elaborate on that here.
  • Ostrich should have few to no quills when
    delivered and no knife cut holes. Skins that come
    from the larger ranches are usually well handled
    today, but the smaller suppliers have been known
    to deliver skins heavy with very undesirable,
    sometimes already rancid, fat, even meat chunks
    and enough feathers to look like feather dusters!
    By now suppliers should be sophisticated and
    skilled enough to deliver properly flayed skins
    in both of these major exotic categories. It is
    up to the tannery to insist that they will only
    accept deliveries that are.
  • Only a very minimum , if any, of 3 grade
    alligator skins are acceptable in a quality
    shipment. Any shipment with higher quantities of
    3 grade should carry an agreed price way below
    market and be designated to be made for

43
  • reduced-price, specifically contracted orders.
    Inspection on the back lighted table described
    earlier for alligators will reveal some not easy
    to spot flaying knife cuts (experienced farmers
    or packers use air knifes almost exclusively
    today, so cuts should be rare), holes and
    scratches or scars that penetrate beyond the
    surface of the scales. Excesses of any of these
    defects will cause a skin to be downgraded to a
    3 grade. This is where the defects have to be
    caught. The tanner who is not sufficiently
    diligent in his receiving inspection will only
    have to pay for that mistake when he has to
    downgrade the skins in the shipping room. Buyers
    reject from their receiving inspection will only
    have to pay for that mistake when he has to
    downgrade the skins in the shipping room. Buyers
    reject from their receiving inspection any low
    grades not specified in their order contracts.

44
  • At this point it is well to note that there are
    two distinct presentations for alligator skins,
    back cut and belly cut. More conventional has
    long been the back cut, cut down the centerline
    of the back. This skin, lying flat, has a row of
    horns running along the length of each side with
    the belly whole and in the center. Those horns
    have in the past been trimmed off and used for
    special end products. In more recent years, a
    market for belly cut skins has become popular. In
    this case the cut is made down the length of the
    belly. This skin has the complete array of horns
    in the center with a belly strip along each side.
    The cut produces what is known as hornbacks. It
    does not lend itself easily to glazed classic
    finish, but can be made into very interesting
    mellow softee products that have shown
    considerable demand by some specific markets like
    many of the boot and belt makers.

45
  • Equipment
  • Id like to say a few things about the equipment
    in the plant I have been discussing. Weve talked
    about things like instantaneous hot water
    heaters, inspection tables, fleshing and shaving
    machines and dryers. I direct your attention to
    processing vessels, shaving machines, glazing
    equipment and dry cleaning, yes dry cleaning
    equipment.
  • Drums and Processing Vessels
  • Regarding the main vessels for processing, all
    I can say is that in this day and age there are
    lots of goodies available with all kinds of
    choices. Some good stuff is still manufactured in
    the states but a far greater variety of
    innovative vessels is made in Europe and
    elsewhere. Drums and paddles constructed of
    exotic woods, fiberglass and stainless steel are
    available. Some are belt, some gear driven with
    or without RPM and rotation

46
  • reversibility. Some require concrete
    foundations, others have wood and still others
    come with steel mounting framework. They can have
    interior Y compartments, shelves, stationary or
    moveable baskets inside or different sizes,
    numbers, shapes and composition of pegs
    distributed on the walls, and all kinds of access
    ports and door construction and location. Even
    variants on the so-called hide-processor design
    (cement-mixer configuration) are widely used.
    Many different mechanisms for wet and dry
    chemical feeding, filtration, re-circulation,
    interior mixing, float volume measurement as well
    as continuous pH and temperature monitoring are
    offered.
  • I have worked with a number of different styles
    and made satisfactory product using all of them.
    I suggest some time be spent investigating the
    different varieties, if possible, at one or more
    of the big international leather shows where many
    competing products are on view to be compared.
    Significant

47
  • considerations for this part of a new plant plan
    (other than the size of the original capital
    outlay) are
  • Simplicity and effectiveness of design
  • Ease of operation and maintenance
  • Chemical resistance
  • Predictable durability inside and out
  • Rugged ability to withstand tannery environment
  • Reliable access to spare parts
  • History of the manufacturers dependability in
    supporting his product
  • Gentle action on the delicate exotic skins during
    processing
  • Capacity
  • Personally, I prefer tilting paddles constructed
    of heavy-
  • duty fiberglass with built-in drainage and
    reversible paddle
  • wheels for the so-called beaming processes.
    Large

48
  • PVC piping to deliver high water volume quickly,
    needs to be provided. It is absolutely vital that
    such piping can be pulled out of the paddle when
    it is charged with skins so there is no way for
    possible hot water drips to enter the paddle
    during the long process. Equally important here
    are check valves and double shutoffs to guard
    against unintended hot water intrusion. Variable
    speed timer-controlled paddle wheel drive system
    is highly desirable. The paddle wheel is not only
    gentle, but it gives excellent mixing. Paddles
    permit continuous observation of the progress of
    the process as well as sampling for controls.
  • For pickling, tanning, retan and coloring I
    would select for my ideal a rugged heavy duty
    wood or even fiberglass
  • construction with all the fixings that could be
    expected to

49
  • hold up over the years
  • Solid construction with components that could
    withstand the highly acid conditions to which
    they will be exposed is mandatory. You dont want
    to be caught replacing one of these babies every
    couple of years, believe me.
  • Interior fixed or rotating Y-shaped baskets or
    similar devices
  • Door systems and wash ports that not only seal
    tightly, are easy to open and close, dont pose a
    major health problem for the backs of operations,
    and can readily be repaired after use, are
    important factors in the selection process.
  • Drives controlled by a dependable timer that can
    reverse rotation direction and set rotation at
    very low RPM are what I would recommend.
  • With all the innovations available today, I
    still have to
  • remind myself that good old solid wood drums have
    often
  • outlived the tanners who used them!

50
  • Shaving Machines
  • Used small cylinder shaving machines suitable
    for exotics may still be found around the US.
    However, for new machines, I think one has to
    turn to Germany or Italy for sources. This is
    another reason for attending tanning machinery
    shows during the planning stages of a new plant.
  • Glazing Equipment
  • Glazing jacks present another problem of
    availability from US sources. Small side glazing
    jacks re required for gators. Sources for the
    right size and composition of agates and cut
    straps for these machines are not easy to find.
    But they do exist. An ample supply should always
    be kept in stock to provide for time delay
    acquiring replacements. The same applies to
    suitable leather bed straps for these machines.
    These are little but quite important details to
    take care of.

51
  • Degreasing/Dry Cleaning
  • One expensive piece of equipment that belongs in
    the kind of tannery I have been talking about is
    an automatic dry cleaning machine. Not everyone
    will think of including this. Woolskin and sheep
    tanneries are probably the only other places
    where dry cleaning to remove excess fatty
    material is necessary and utilized. It can save a
    lot of grief in the processing of alligators and
    ostrich in particular. Let me add a word of
    caution on upkeep of this machine. It is likely
    to be the sole source of volatile solvents in the
    entire plant. To avoid problems with effluent,
    the dry cleaning machine has to be totally
    isolated from any possibility of spills into the
    waste water system. When it is cleaned, when the
    filters are flushed, all the time, anything
    liquid that comes out from the machine has to be
    totally captured and not allowed to contaminate
    any other waste. Spent solvent must be disposed
    of separately by

52
  • solvent recovery or as permitted hazardous waste
    by licensed haulers--no shortcuts in this area at
    all!!
  • At the start of my presentation I cautioned
    that a good, modern exotic tannery requires a
    good deal of capital to set up. It should not
    require any fancy computer spread sheets to come
    up with a quick estimate of the cost for what I
    have outlined so far amounting to some pretty big
    bucks--and thats without even considering
    processing or inventory costs!
  • Secrets of Exotic Leather Manufacture Critical
    Processing
  • Strategies
  • Now Ill discuss a few process key points that
    you have been patiently waiting for me to get
    around to. Please dont expect me to present you
    with a recipe for making alligator or ostrich
    leather, because that is not my intention. But I
    will

53
  • pass along a number of the critical things that
    contribute to making good exotic leathers. The
    process methods I will describe really are
    intended for alligators. That is where I believe
    the supplying industry has developed the most
    stable quality raw material sources as of now. A
    steady flow of good raw material, necessary for
    production planning, can be counted on from the
    alligator farms. Ostrich ranching here in the US
    is not far behind. Most of the basic chemistry
    for alligators will also work for ostrich, but
    ostrich pelts are not quite as delicate to
    handle.
  • Things that are different with alligator and
    ostrich processing than with cattle hides are,
    for example
  • batch size
  • time in process
  • precision of quality-control measurement.

54
  • When I first realized the number of exotic units
    considered a decent months production volume, I
    remember saying Wow, most of the other plants
    Ive worked in produced a much higher number of
    units than that before the morning coffee break
    on any given day. Each piece was much bigger,
    too!
  • This merely emphasizes the high value of each
    skin going through an exotic plant, and why that
    brings about a need for even greater caution and
    tighter quality controls in all the handling
    stages. At various points in a bovine plant,
    there are trimming operations where
    machine-caused hanging pieces and animal defects
    are cut off. When you are dealing in centimeters
    of width measurements, as you are with gators,
    great machine operator skills are vital to
    prevent ragged edges requiring trimming. And
    upgrading had better be accomplished in the
    receiving department by rejecting poor

55
  • quality skins at the back lighted sorting table!
    Scales on gators allow most defects to be seen,
    but the hair on raw cattle hides does not.
  • When a formulation calls for grams per liter
    and the liquor is supposed to have a designated
    specific gravity, the Baume/ as well as the
    temperature need to be precisely within the
    specified ranges. If only so many turns or
    minutes of paddling or drumming are specified in
    the formulation, that is what has to be followed,
    or else the delicate grain layer may be scratched
    or otherwise damaged. The value of the skins
    making up any given batch is too high for any
    casual execution of formulations. (Casual or
    careless attitudes have been known to almost
    result in some other kind of executions when an
    irate tanner became overly provoked!!) It is
    important to remember that during the early
    stages of the process, the temperature sensitive
    purified collagen protein

56
  • will degrade into gelatin just as in the gelatin
    and film making business where the starting
    product collagen is subjected intentionally to
    elevated temperatures. If hot water contacts the
    skins before they have been made thermally stable
    by tanning crosslinkages, they can gelatinize
    irreversibly! That is a real tannery disaster
    possibility needing means of prevention at any
    cost!!
  • Things move more slowly through an exotic
    tannery than through large bluing plants or upper
    leather tanneries. In the early stages of the
    process things cannot be rushed. Formulations
    have to have time flexibility built in to allow
    for close inspection of the progress of each
    operation to determine if the proper end point
    has been reached. If not, then whatever
    additional time is needed has to be added. It is
    not always possible to say this goes in today and
    comes out at a specified time tomorrow. Sometimes
    a batch may require

57
  • another day or even more so that is what it has
    to get. If the cake is not ready, leave it in the
    oven! This would defeat a modern production
    bovine plant, but it is just one of the things
    that will separate a successful exotic plant from
    that other mode.
  • Think of natural fat as the enemy. It must be
    eradicated as early and as completely as
    possible. Fats can block penetration of and even
    react with tanning and coloring ingredients. Fats
    will show up in the finished product in the form
    of color difference, stains or surface dullness.
    They raise all kinds of headaches on products to
    be glazed. For all these and other reasons,
    appropriate degreasing efforts have to begin with
    the very first soak and continue through the wet
    processes. And, later in the process, topping it
    all off, any residual natural fats still in the
    dried crust must be finally extracted in a dry
    cleaning apparatus and then the skins should

58
  • look absolutely clean, beautiful, stain free and
    ready for finishing into fine leathers.
  • That old tanners line that leather is made in
    the beamhouse is nowhere more true than with
    exotics, so I will now discuss some specific
    control points for modern exotic skin beaming
    procedures.
  • Soaking and Scouring
  • First of all, to achieve best possible fat
    removal, I suggest a presoak followed by a wash.
    Overnight main sock with brief intermittent
    paddling, fleshing to clean off any adipose
    tissue and create a very smooth back surface,
    then weighing to establish a new formulation
    basis for the subsequent wet operations follow.
    And after that I still suggest an additional
    2-day degreasing soak with occasional brief
    mixing. In each case, of course I suggest
    incorporation of good biodegradable surfactant
    detergents, LOW concentrations

59
  • of appropriate enzymes, and approved
    biodegradable biocides into the bath. The skins
    should be pulled after this soak so the descaling
    bath can be prepared. As you can see, there is a
    lot of extra handling involved here and that all
    contributes to the high cost of exotic
    processing. It also contributes to high cost by
    adding to the overall process time during which
    inventory capital has to be covered.
  • Descaling
  • The descaling bath has to be prepared before the
    skins are loaded because Sulfide
    (Na2S)/Hydrosulfide (NaSH) solubilizing produces
    an exothermic reaction. It has to be prepared in
    advance into a concentrated approximately 20 Be/
    solution that then is allowed to cool and then
    measured and added to the paddle liquor until the
    desired Baume/ and temperature is set. Some
    Calcium Chloride to control rate of

60
  • swelling and, once more, some surfactants
    should be mixed into this bath before the skins
    are returned to the paddle. After the first 24
    hours with periodic brief paddling, the
    de-scaling should be nearly complete, the skins
    now opaque and nicely plumped. On second day the
    paddle should be recharged with about a fifth of
    the first days sulfide charges.
  • Liming
  • Once the scales are completely off, a small
    quantity of powdered lime Ca(OH)2 is added to
    help with removal of the epidermal layer (amount
    is calculated as grams of powder per liter of the
    combined total volume of Sulfide solution
    previously used). A brief mixing, then
    intermittent, brief paddling overnight follows.
    Day three is critical to the final product
    quality. A very close inspection of the surface
    is needed now to determine whether or not the
    epidermal layer is completely removed. If there
    is even suspicion that some

61
  • might still be present, this is the place where
    it has to be taken care of. Any residual
    epidermis after the complete liming will show
    up as dull areas on the finished product. It is
    too late to try to get rid of it once the skins
    leave the liming bath. To clear any residue, day
    two Sulfide and lime feeds need to be repeated
    followed by another night of intermittent
    paddling. The results under close examination
    should then be pelts absolutely free of any
    evidence of epidermal tissue. The lime liquor is
    drained from the paddle and then several closed
    washes (drain, fresh float, paddle, drain, etc.)
    until pH between 10.5 and 10.7 is attained and
    the skins are quite clean. The skins are left in
    the final wash float overnight with intermittent
    brief paddling and pulled out and allowed to
    drain the next morning, while a deliming float is
    prepared in the paddle.

62
  • Deliming
  • Deliming is nicely done with Ammonium Chloride.
    The amount used is based on grams per liter of
    the float and again some detergent is included in
    the bath. After intermittent overnight paddling
    (i.e. 5 to 10 minutes every 2 to 3 hours),
    deliming should be complete. The spent deliming
    liquor is replaced with another closed wash at
    temperature slightly elevated to approximately
    85o F.
  • Clipping
  • Until deliming, the skins are able to slip over
    each other without knotting (assuming the floats
    are adequate and the paddle is not overloaded).
    The balance of the operations create drag and
    friction so, before they can be transferred to a
    drum for the other processes, another key
    caution, each skin must be clipped tail to near
    the front legs to prevent

63
  • tie-ups. Without this precaution, it is
    possible, if not likely, that a huge ball of
    skins will develop inside the drum. That will
    wreak havoc with the process and the skins.
    Available are heavy-duty versions of the
    needle-nosed guns like those used to clip tags
    on garments for retail sale. These do a
    reasonably good job, but some will break and need
    re-clipping as the process progresses. As far as
    I know, there is no shortcut machine to do this
    tedious individual skin clipping, but it cannot
    be avoided.
  • Bleaching and Pickling
  • Bleaching and pickling processes for gators are
    probably where the greatest differences from
    other raw materials are found. This is where any
    residual pigmentation is bleached out and the
    bony substructure under the horns and other areas
    of the skins is softened. It is the slowest part
    of the

64
  • process.
  • Precautions are
  • Handling of the ingredients, which are hazardous
  • Monitoring against temperature elevation
  • Adequate brine concentrations throughout
  • Close pH control
  • Stock must be salt brine saturated at pH 7.5 to
    8.0 before the
  • undiluted bleaching agent is applied. Sodium
    Chlorite
  • (NaCIO2) is a highly effective bleaching agent.
    This
  • and the acid feeds that follow it require careful
    training of
  • operators in safe handling techniques.
    Hydrochloric Acid
  • (HC1) diluted in salt brine is fed separately
    after Chlorite,
  • undiluted, is mixed into the skins by brief
    drumming. Using
  • HC1 as the acid further contributes to the
    bleaching itself.

65
  • The bleaching takes about a day and a half to
    complete with just 2-3 minutes of drumming each
    hour. Once complete skin bleaching is observed,
    dissolved Sodium Thiosulfate is used to kill any
    free chlorine in the liquor. The main pickling
    process cannot begin until starch/iodide test
    paper shows up colorless. All the intermittent
    paddling and drumming operations mentioned above
    will be simple to apply if variable speed
    controls described under equipment are connected
    to the different drives. Throughout these
    processes, operators must show extra respect for
    the potential of contact with dangerous chlorine
    fumes. High volume exhaust needs to be running
    during the entire process.
  • Main Pickling
  • This process involves slow feeding high
    percentages of HC1 (always carefully diluted in
    concentrated salt brine) spread

66
  • out over a matter of hours and then
    intermittently drummed briefly over a period of
    at least 3 to 5 days. Between bleaching and
    pickling, more than 20 per cent of acid can be
    consumed. Daily additions of acid are required to
    maintain extremely low pH--well below 1.0. This
    is continued until the horns are fully softened.
    Brine washes follow the completed pickling and
    the skins are ready for tanning.
  • Tanning
  • From this stage on, the chemical processes are
    where the tanner can use his or her own formula
    wrinkles and additives to arrive at well-tanned
    skins for which by now they have been well
    prepared and will be fully receptive. Tanners
    experience, his product development results, and
    advice from chemical supplier consultants are
    combined in the balance of the wet processes to
    build the specific distinguishing

67
  • character of each tannerys leather into the
    final product. Sufficient chrome to obtain a
    fully penetrated evenly distributed tannage along
    with whatever buffers and auxiliaries the
    individual tanners product development dictate.
    The many different fine chrome compounds being
    offered today can be formulated to produce very
    high exhaust liquors, finishing with a pH 4.0 to
    4.2, even chrome distribution, and high shrink
    temperature. At the completion of the tannage,
    some ecologically friendly antifungal product is
    required to prevent mold growth during storage.
    Typically the tanned stock needs to stand and
    drain for a week before shaving and then weighing
    for retannage.
  • Retannage
  • Retanning and fatliquoring are combined in a
    separate wet operation for gators. In retanning
    the tanner get another opportunity to exercise
    creative individual know-how and

68
  • experience. Combinations of vegetable extracts
    and synthetic tanning agents, straight vegetable
    extract or straight synthetic tanning agent
    retans combined with the appropriate softening
    agents can be worked out to give the different
    leather wanted by the tanner and his customers.
    The right combinations will yield supple, lightly
    colored or pure white stock ready for drying. The
    crust produced will emerge from careful drying
    systems such as described earlier, ready for dry
    cleaning or buffing, and in ideal condition for
    coloring. There are plenty of capable people out
    there in the specialty leather chemical supply
    business who are anxious to offer help in
    demonstrating their auxiliaries, oils and other
    additives for producing the premium products.
  • Coloring
  • There is little difference between coloring
    exotics that have

69
  • outlined and colorin
About PowerShow.com