Hides and skins
|Infobox on Hides and skins|
|Example of Hides and skins|
|Stowage factor (in m3/t)|
|Humidity / moisture||-|
|Ventilation||Adequate circulation of air|
|Risk factors||Heating, wetting, mechanical influence (contact with metal) decomposition due to bacterial action|
Hides and skins
A hide is an animal skin treated for human use. Hides include leather from cattle and other livestock animals, alligator skins, Snake Skins for shoes and fashion accessories and furs from wild cats, mink and bears. In some areas, leather is produced on a domestic or small industrial scale, but most leather making is done on a large scale. Various tannins are used for this purpose.
Animal hides are stretched, dried and tanned. It is more cost-effective today to raise animals in captivity and then kill them. Large farms exist to raise mink and rabbit for fur while much fox, lynx, wolf and other animals are trapped for fur.
Fur and hides find their main use today as clothing, particularly coats. They are valued for their warmth, and as a status symbol. Rabbit fur is a popular material to make hats, coats and glove linings. Ermine fur was historically popular in ceremonial clothes of European monarchs. The black-tipped tails were arranged around the edges of robes, producing the familiar pattern of black diamonds on a white field. Because of this use, "ermine" became a term in heraldry, to mean a white field strewn with small bell-shaped designs called ermine-spots.
Leather from processed hides has a variety of uses, including shoes, clothing, horse tack, horse harness, upholstery and even wall or other surface coverings.
Shipment / storage / usage
Hides and skins are shipped in bales, bundles, casks, barrels, bags, loose or palletised in freight containers.
Any animal hide or skin is of fibrous texture and from the moment of slaughter is liable to decomposition due to bacterial action. This decomposition is only completely stopped when the hide or skin is tanned, but can be halted temporarily by salting and/or drying.
Hides are shipped as Wet-Salted (Brine-Cured), Dry-Salted and Dry. These methods of preservation are effective for fairly long periods, provided that the curing or drying has been satisfactorily carried out, and conditions of storage and transit have not caused the curing or drying to become ineffective. Climatic conditions at the time of preparation may have some bearing upon the condition and appearance at destination, e.g. , skins which have been salted and dried in the heat of the summer may tend to become somewhat overdried and although not damaged are liable to be broken or torn if roughly handled, more particularly in the case of a poor type of skin. Surveys should be called before the skins have been put to work and thereby lost their identity. The surveyor has a better opportunity of examining skins in the original bales and thus of ascertaining the cause and extent of the damage.
Salted skins once having been wetted will readily absorb moisture from the atmosphere. This may give rise to a wrong impression as to the length of time which has elapsed since wetting.
Wet-salted hides are liable to decompose through heating if not adequately salted or if exposed to high temperatures in stowage or to a fairly high temperature for an extended period. Hides may be lightly cured to preserve them for short periods, or more thoroughly cured when they need to be transported over long distances. Hides stored under salt for a long period have a stale appearance and if deterioration has started to set in, the first indication will be looseness of the hair or ‘hair slip’. In advanced cases this is accompanied by a smell of ammonia and obvious signs of decomposition. Hides already stale when shipped will lack resistance to adverse conditions during transit, and may deteriorate when well-cured fresh hides would not be affected. ‘Hair slip’ may also arise in hides which have been subjected to heating, as the looseness of the hair is brought about by bacterial action. Red stains on the flesh side of the hides (‘red heat’) are also an indication of heating; in early stages this need not signify damage, but in more advanced stages will be accompanied by other signs of damage. When hides are seriously heated, the fibrous structure of the pelt will have been destroyed with serious results. ‘Red Heat’ may also be found in dry-salted hides and skins, but in this case the skins will usually have been wetted or have been damp at some time. It is the result of salt-loving bacteria which progressively break down the hide substance.
Hides and skins of all descriptions can be seriously damaged if wetted by fresh or salt water. The effects are more rapid on dry hides and skins than on salted, but the latter will become severely damaged if wetting has been sufficient to remove much of the salt. Wetting allows bacteria to thrive to the detriment of the pelt, and decomposition will be accentuated if the wetting is accompanied by heating, which is particularly liable to occur in press-packed bales. Salted hides and skins may absorb a certain amount of moisture from the humidity of the atmosphere, but this does not constitute damage, and normally does not affect the skins. Dry hides and skins may absorb moisture to a limited extent if the atmosphere is very humid; a slight mould will form on the surface of the skin. This may not be harmful, but much will depend on the degree of moistening and the length of time the skins have been in this condition. Wetting prior to shipment or from sweat during the voyage may produce similar effects. If skins have been packed damp, a mildewed condition may exist, but this will clearly be of an internal character inside bales, as distinct from the effects produced by external wetting. Dry and dry-salted hides and skins are not liable to sweat from inherent causes.
Inferior quality hides are liable to develop holes due to a skin defect, and care should be taken not to attribute this holing to the use of hooks or other fortuitous cause. The skins concerned are usually those with a rough surface, and careful examination of the holes will make it comparatively easy to determine whether this has arisen through the use of hooks or other fortuity, or whether it is a defect in the kin itself. When the hole is due to a defect, the surface immediately surrounding the hole is not usually as smooth as the remainder of the hide or skin. The skin may also suffer from blemishes which may eventually result in further holes. These holes and blemishes are usually accepted in the trade as being defects of the hide or skin itself.
Hides and Skins in Freight Containers
Hides and skins may be carried palletised in freight containers. Containers must be lined with plastic or other impervious material. Heating may occur if insufficient ventilation is provided. Loaded containers should not be exposed to direct sunlight or heat as this will lead to heating and heavy damage. Containers should be so stuffed as to allow adequate circulation of air.
Contact with metal - Contact with iron or copper can, if allied to moisture, lead to serious damage in a relatively short time.
Treatment - Where damage is not severe enough to warrant goods being classed as useless, damaged skins should be put into work immediately; discarded skins may be sold for glue manufacture. Unless water-damaged hides are dealt with promptly, damage will be considerably aggravated as the result of bales being left unopened or stored, decay in the skins advancing rapidly if air has no access to them.
Basils (Australian tanned Sheep and Lambskins) - Usually satisfactory cargo. Liable to damage from wetting. Damp packing very rare.
Dry Salted – Mostly IndianUsually well packed and prepared for shipment in press-packed bales. Most likely cause of damage is external wetting. May become mildewed internally if packed slightly damp under monsoon conditions.
Shade Dried – East and West African, etc. Usually well dried and prepared for shipment. Liable to heavy damage from wetting, slight wetting may cause considerable mildew. Mildew may also result from damp packing. Liable to worm damage.
Wet Salted – Mostly Indian – Packed in casks. Are liable to heavy damage from exposure to heat and heating. Similar troubles arise from improper salting before packing.
Susceptible to heating which ‘cooks’ skins. These tear easily, rendering them useless.
Lamb and Sheep – Mostly shipped in casks. Liable to deterioration and damage if exposed to heat and water. Will also deteriorate if pickled unsatisfactory.
Improper curing can cause mould damage which is easily mistaken for damage due to contact with water or sweating in transit.
These are shipped dry, dry-salted and wet-salted. The same conditions apply as above, except that wet-salted skins are usually shipped in casks.
Dry Salted - Usually carry well, but can be damaged by wetting . Sometimes absorb moisture during very humid weather, but this dampness may not result in damage.
Shade Dried – African, Ethiopian, Indian, etc. – Can deteriorate quickly after wetting by fresh or sea water. Damping by rain before shipment may result in heavy mildew on bales or hides, not to be confused with similar mildew which may result from insufficient drying before packing. Liable to attack by worm or weevil (Dermestes vulpinus) which may be inherent or contracted in transit.
Sun Dried – Similar to above, usually more common types. May suffer from incorrect drying in too great heat. Wet Salted – Australian, New Zealand and South American – Freezer works and abattoir hides are usually well prepared for shipment. Can be damaged by wetting due to loss of salt content. Chief danger is from heating usually resulting from exposure to heat, faulty stowage, inadequate ventilation, or delays in transit. Damage may result from insufficient salting, but this is most unlikely with freezer works and abattoir hides.
Raw Sheepskins and Lambskins
Australian, New Zealand, South African, South American – These are usually shade dried in abattoir conditions and shipped in press-packed bales. The chief cause of damage is wetting, but they can become heated and badly mildewed, or attacked by black mould, through damp packing. These skins are also subject to attack by worm or weevil which may be inherent or contracted during transit.
Dry Salted – Indian – Usually well packed and prepared for shipment in pres-packed bales. Most likely cause of damage is external wetting. May become mildewed internally if packed slightly damp under monsoon conditions.
Dry Salted – Red Sea Area – Most likely cause of damage is wetting from external causes.
Dry Salted – Australian, New Zealand, South African, etc. – Usually well prepared for shipment in bales. Chiefly subject to damage by water, but liable to absorb moisture during very humid conditions, which may be harmless but may give rise to red heat or black mould.
Dry Raw Hair – Arabian, Ethiopian, etc. – These are usually well prepared for shipment in bales with naphthalene and gammexane as protection against worm. They will deteriorate rapidly if wetted.
Shade Dried – East and West African, etc. – Usually well dried and prepared for shipment. Liable to heavy damage from wetting. Slight damage cause considerable mildew. Mildew may also result from damp packing. Liable to worm damage
Wet Salted – Indian – Packed in casks. Are liable to heavy damage from exposure to heat and heating. Similar troubles can arise from improper salting before packing.
Sheepskins and Goatskins, East India Tanned Hides
Usually most satisfactory cargo, but can be severely damaged by wetting and subsequent heating. May be packed damp during monsoon conditions, resulting in mildewed condition inside bales.
Sheepskins and Goatskins, Semi-Tanned
Baghdad, Syrian etc. – As above, but tend to deteriorate more rapidly after wetting. Contain salts used in manufacture which may attract moisture in very humid conditions.
More information on hides
Hides are normally only accepted in DRY containers - The hides are only acceptable if they are shrink wrapped and the container is fitted with one of the approved hide Liner Bags and then only with ample use of absorbent sawdust on the floor. It is important that the liner is not cut in the container doorway to facilitate door opening/loading as once cut, the liner looses any liquid retaining ability when the container is handled/tilted. Shrink-wrapping is not sufficient.
NOTE - SOME HIDES CAN BE SHIPPED IN OPERATING REEFERS BUT ONLY WITH THE PERMISSION OF CARRIERS
Hide liner specifications as follows: Hides liner: film weave of Polyethylene (PE) 850 denier woven at 10x10 mesh per square inch coated with PE to 30 microns thickness each side. Overall weight 110-120 grams. The liner must be firmly affixed inside the container
The following additional lining procedure is suggested:
- Container floor and 3 feet/1 meter up the walls lined with CCB minimum 1/4"/0.5cm thickness to prevent ripping/tearing liner on burrs/nails/protrusions on container walls and floors
- Container floor lined with Particle Board minimum thickness 3/16"/0.5cm to prevent tearing of liner by forklift wheels/pallets.
- Ample sawdust applied as usual.
The only exceptions to lining are for AIR DRIED hides, which are properly dried and devoid of any wetness or dripping, and have a maximum moisture content of 10-15%. These may be shrink-wrapped.
Hide containers must not be stowed in the bays next to the accommodation, preferably they should be stowed in the foremost bays in rows close to outboard side but not over walkways.
All hide containers must be stowed on deck and must never be stowed on top of any reefer containers (live, NOR or empty). Hides may be stowed beside or under a live FROZEN REEFER or live CHILLED REEFER only with VENTS SHUT, but may not be stowed beside or under a live CHILLED REEFER requiring ventilation.
Vessel masters must be presented with stow positions of on board hide containers at time of loading to enable pinpointing of leakage.
Leaking containers are not allowed to be loaded at all and should be returned to the shore at once.
It is frequently seen, that despite correct lining procedures, the stuffing method used will cause tearing of the liner and the purpose of retaining the run off is defeated, resulting in additional costs for cleaning up onboard ship and in terminals wherefore correct stuffing supervision and spot checking of hide shipper's stuffing operations should be performed regularly.
- Mechanical influence (contact with metal)
- Decomposition due to bacterial action