IC

See: Ion-exchange Chromatography.

Ice (v); icing

Process of chilling or preserving with ice.

Identification systems (traceability)

Various permanent marking methods that will enable  traceability from the live animal to the dry finished leather.

Irrespective of the technique of the system, identification must always be performed at the abattoir, as this is the only stage the animal’s identity, origin (farm) and slaughter code number can be linked with the flayed hide or skin.

See: Ear-tags; brand.

Immature keratin,  (soft)

Softer, less highly condensed and less chemically resistant form of keratin, composing the newly formed epidermal cells and the hair and wool roots.

Immediate Oxygen Demand (IOD)

Indicates the immediate oxygen demand that is required for a short term oxygen consumption without micro-organisms intervention.

Immersion dyeing

Dyeing process in which the skins, usually paired flesh to flesh, are repeatedly dipped into, and removed from, the dye liquor contained in a trough.

Immersion process

Process of dyeing in which leathers are immersed in a mordant, dye or other solution.

Impregnated bend

Sole leather bend which has been impregnated with wax, hard grease, rubbery polymers or other agents in order to make it more water-resistant and/or durable.

Impregnated leather

Sole leather bend which has been impregnated with wax, hard grease, rubbery polymers or other agents in order to make it more water-resistant and/or durable.

Impregnation

Introduction of a liquid substance into the spaces of a porous solid in order to change its properties.

Inactivate (v); inactivating

Change reactivity of a chemical group, from an active group into an inactive group.

Note: An –NH₂- group to an –OH- group by treatment with nitrous acid or a –COOH group to an ester group by means of dimethyl sulphate.

Incineration

Controlled high temperature oxidation of primary organic compounds. This oxidation generates gas, fumes and solid residues called ashes and scorias.

Incinerator

Equipment to incinerate solid or liquid waste.

Inert

Something without active chemical, physiological or other properties.

Infrared drying

Through-feed dryer using radiant heat which is absorbed instantly by the exposed wet leather surface, evaporating the water.

Infrared radiator

Device, usually heated by electricity or gas, for generating infrared radiation and specially used for drying aqueous finish coats.

Inorganic pigment

Homogenised, finely dispersed coloured inorganic substances which are insoluble in water and organic solvents. Used in finish preparations to give good covering properties.

Insole leather

Hide leather, including flexible splits, vegetable or combination tanned, in sides, bends, shoulders and bellies, suitable for the inner soles of footwear.

Integrated Pollution Prevention and Control (IPPC)

EU Directive that must be implemented in all Member States from the end of October 1999. It is being introduced across Europe to improve the standard of environmental protection. The purpose of the Directive is to achieve prevention and control of pollution arising from the range of activities listed in its Annex 1. It lays down regulations designed to prevent, or where that is not practicable, to reduce emissions to air, land and water from these activities, including regulations concerning waste. This is being done in order to achieve a high level of protection of the environment, taken as a whole.

Interface

Surface that forms the common boundary between two liquids.

Interfibrillary matter

General term for various chemical substances (proteins, glycosaminoglycans, etc.) and structural elements (for instance cells) existing between the collagen fibrils of connective tissue. This material is often referred to as “ground” or as “cementing substance”, perhaps because it coagulates on drying.     

See:  Hyaluronic Acid; glycosaminoglycans.  

Interlocking device (interlock)

Mechanical, electrical or other type of device, the purpose of which is to prevent the operation of machine elements under specified conditions (generally as long as the guard is not closed).

International contract

Agreement between the trades organisations ICT and ICHSLTA establishing the terms of trade for the sale/purchase of “Hides and Skins”, defined in the International Contract No 6, and “Finished Leather”, defined in the International Contract No 7.

International Organisation for Standardisation (ISO)

A non-governmental organisation established in 1947 whose mission is to promote the development of standardisation and related activities in the world, with a view to facilitating the international exchange of goods and services and to developing co-operation in the spheres of intellectual, scientific, technological and economic activity.

International Register of Potentially Toxic Chemicals (IRPTC)

UNEP scientific tool for recording and sharing data used to assess the hazards posed by chemicals to human health and the environment.

IOD

See: Immediate Oxygen Demand.

Ion-exchange Chromatography (IC)

Chromatographic procedure in which the stationary phase consists of ion-exchange resins which may be acidic or basic.

Ionise (v); ionising

Split, change, or become changed into ions.

IPPC

See: Integrated Pollution Prevention and Control.

Iron (v); ironing

Rotary heated metal surface used to achieve a smooth and/or glossy appearance to the grain surface of the leather. Also used on woolled sheepskins to straighten and give a gloss to the wool fibres.

Iron oxide determination

Determination of any of the hydrated, synthetic or  natural oxides of iron: Ferrous oxide, ferric oxide.

Iron stain

Contact with iron (rust) causes wet staining and eventual deterioration of leather.

Iron tannage

Tannage with trivalent iron salts and especially with certain complex anionic compounds.

Ironing plate

Polished and heated steel plate against which leather is pressed in the plating or ironing machine.

IRPTC

See: International Register of Potentially Toxic Chemicals.

Irradiation

Systematic exposure of hides coming from the flaying room, to ionising energy to effect chemical or biological reactions which induce a low temperature sterilisation.

Irregular dyeing

Dyeing not regular, uneven and imperfect. Not the same colour over all the surface.

Irritant

Product or preparation, which can produce irritation in a short, prolonged or repetitive contact with the skin or the respiratory tract. If it is in contact with the skin, eyes or mucous membranes, can give rise to reddening or inflammation.

ISO

See: International Organisation for Standardisation.

ISO 9000 - 9001 - 9002 - 9003

Set of quality standards for the implementation of Total Quality Systems.

Isocyanate

Compound containing two or more isocyanate groups, such as  hexamethylene di-isocyanate, OCN.(CH₂)₆.NCO; can be used as a tanning agent or for the cold lacquer process for patent leather  (polyurethane process).

Isoelectric point

Point or narrow range on a pH scale at which the concentration of the anionic part of an ampholyte equals that of the cationic part: the pH at which the ampholyte will not migrate in an electrical field (the isoelectric points of most proteins range from pH values of 4 to 7).

The isoelectric point (or region) of leather is different from that of the raw hide or pelt collagen (5-6); it is shifted by vegetable tannage to the acid side and to the alkaline side by the usual cationic one bath chrome tannage.