|
Ear tags
|
Small plastic labels attached
by one end to the ear of an animal indicating ownership, origin,
etc., and serving as an identifying mark that enables producers
to identify cattle individually without the hide damage caused
by fire (iron) and freeze branding. Bar code-carrying ear tags
when used as ‘tracers’ may allow the linkage of slaughter data
with those of the farm and promote hide improvement.
|
|
Easy-care finish
|
Type of finish which is particularly
resistant to oil, grease and soiling, wet and dry rubbing and
to solvents and detergents.
|
|
Eco label
|
Labels for a product which fulfils
a set of requirements regarding the protection of the environment.
|
|
Eco product
|
Product which is recognised as
respecting some requirements regarding the protection of the
environment
|
|
EDTA
|
See: Ethylene Diamine Tetra Acetic
Acid.
|
|
Effluent
|
Generic term denoting wastewater.
|
|
Effluent (untreated raw)
|
Wastewater as it is generated
from the process without any treatment (clean technology may
be included).
|
|
Effluent receiving sump
|
Small tank for the collection
of wastewater before treatment. It is equipped with pump to
feed the effluent treatment plant.
|
|
Effluent treatment plant
|
Plant in which wastewater is
subjected to a process in order to remove polluting substances.
|
|
Egg albumen
|
Commercial product in dried powder
form obtained from the white of chickens eggs and used in binder
preparations for glazed finishes.
|
|
Egg yolk
|
Yolk of hens eggs, used in tawing
and fatliquoring on account of its content of emulsifiers and
lubricating oils.
|
|
Elastic tissue
|
Connective tissue of the kind
that occurs in the dermis and the walls of arteries, chiefly
elastic fibres composed mainly of elastin, a protein similar
to collagen and occurring in networks or sheets in elastic tissue
to which it imparts elasticity.
See: Bate (v); bating.
|
|
Elasticity
|
Property whereby
a material changes its shape and size under the action of opposite
forces but recovers its original configuration when the forces
are removed.
|
|
Elasticity endurance
|
Ability of a finish to resist
stretching, extending or deforming of the leather without tearing,
cracking or peeling off. To test this ability, a lastometer
or a tensometers is used.
|
|
Elastin
|
Very extensible and chemically
resistant yellow, fibrous protein,
occurring in certain vertebrate connective tissue such as a
fine
network in the reticular dermis (corium) layer and round certain
arteries, and as a bundle in the nuchal ligament (the thick
elastic
ligament supporting the back of the skull).
|
|
Electrified fence
|
Barrier made of metal wire which
is insulated from, and fixed to, posts and through which a high
tension, low ampere intermittent current is induced.
Electric fencing has been promoted
as an alternative to barbed wire for many years. However, in
spite of the concrete measures proposed by the Confederation
of Tanners and Dressers of the European Community (cotance),
and the efforts of different national experts, barbed wire injures
continue to be among the most serious cattle skin defects in
the EC.
See: Scars; scar tissue
|
|
Electrocoagulation
|
pr Electrochemical process used on some wastewaters
resulting in flocculation according to the process of creating
an electrical field between electrodes which promotes the polarisation
of anions and cations in the effluent and the release of metallic
ions (Fe, Al) when the sacrificial anodes dissolve; these ions
generate hydroxides which enable floc to form.
|
|
Electroflotation
|
Flotation in which bubbles (H2
or O2) are produced by electrolysis of water using
appropriate electrodes.
|
|
Electron Capture Detector Gas Chromatography (GC-ECD)
|
Chromatography providing
for an extremely sensitive
gas chromatography detector (ECD = Electron Capture Detector)
at high specificity for chlorinated compounds.
|
|
Electronic nose
|
Electronic early detector of
the odours of putrefaction with multiple electronic sensors
in place of human olfactory receptors. The electronic nose mimics
the human sense but with greater selectivity, and detects some
of the initial breakdown products during putrefaction early
enough to prevent the decay and the high financial losses generated.
|
|
Electro-osmotic tanning
|
Process proposed for accelerating
the vegetable tanning process by suspending the hides in the
liquor between two electrodes, separated by permeable diaphragms.
|
|
Electrophoresis
|
Electrochemical process
in which colloidal particles, macromolecules or molecules (deposited
onto a solid support like paper or collodium) with a net electric
charge migrate in a solution under the influence of an electric
current. Also known as cataphoresis.
|
|
Electrostatic swelling
|
Uptake of water by, and the swelling
of, a protein, attributed to alteration of the electric charges
through combination with hydrogen or hydroxyl ions and consequently
repulsion of groups with similar charges.
|
|
Elongation
|
Amount of the increase
in a material’s length when submitted to a tension.
|
|
Elongation at break
|
Amount of the increase
in a material’s length when submitted to a tension until its
rupture.
|
|
Eluate
|
Solution resulting
from the extraction of a solid by a liquid or from a chromatographic
separation process.
|
|
EMAS
|
See: Environmental
Management Audit Scheme.
|
|
Emboss (v); embossing
|
Create a raised design upon a
leather by pressure from a heated engraved plate or roller.
|
|
Embossed leather
|
Leather embossed or printed with
a raised pattern either imitating or resembling the grain pattern
of some animal, or being quite unrelated to a natural grain
pattern.
|
|
Embossing plate
|
Heated engraved plate to emboss
leather
|
|
Emergency stop (function)
|
Function which is intended to:
· prevent or reduce existing hazards to persons,
damage to machinery or to work in progress;
· initiated by a single human action when the
normal stopping function is inadequate for this purpose.
|
|
Emery
|
Hard metallic substance used
for buffing leather.
See: Buff (v); buffing.
|
|
Emery wheel
|
A wheel dressed with, or made
of, emery or carborundum and used on the flesh side of leather
to cleanse it or give it a fine nap.
|
|
Emission
|
Emission of chemicals to the
atmosphere outside the plant or the workshop.
|
|
EMS
|
See: Environmental
Management System.
|
|
Emulsify (v); emulsifying
|
Form an emulsion, dispersing
one liquid throughout another liquid in the form of little drops.
|
|
Emulsifying agent
|
Substance which enables one liquid
to be emulsified in another.
|
|
Emulsifying power
|
Capability of a substance to
produce a stable emulsion of one liquid in another.
|
|
Emulsion
|
Dispersion of two or more immiscible
liquids in which one is dispersed in droplets throughout the
other.
|
|
Emulsion break
|
Separation, breaking of an emulsion
into its two phases.
|
|
EN
|
See: European
Norm.
|
|
EN 45000
|
European Norm for
the certification of laboratories for testing.
|
|
Enamel
|
Uppermost layer of a hide or
skin exposed by the removal of the hair or wool and epidermis.
The enamel appears as a translucent layer and gives the special
properties of smoothness and polish to the grain surface. Any
damage to this surface layer reveals the relatively coarse underlying
fibres.
|
|
Endurance
|
The ability of a leather to resist
surface damage, such as cracking,
when folded, grain outwards, in two directions at right angles
to give a sharp corner. Flexing endurance may be tested by a
machine such as the Bally flexometer.
|
|
Energy recovery
|
Recovery of energy from a process,
or from solid waste treatment.
|
|
Environmental impact
|
Any modification to the environment,
positive or negative, which can be a partial or total result
of activities, products or services of a body.
|
|
Environmental Management Audit Scheme
(EMAS)
|
Voluntary scheme
for environmental accreditation of participating enterprises
that is audited by a competent external verifier according to
the requirements of EC Regulation no. 1836/93.
|
|
Environmental Management System (EMS)
|
System to achieve
environmental targets which is adopted by enterprises and is
certified by an accreditation body. The system is based on the
voluntary compliance of the enterprises, according to the international
norm EN ISO 14000.
|
|
Enzyme
|
Natural catalyst, produced by,
and occurring in, living organisms and responsible for bringing
about certain chemical changes necessary for their life; used
in bating and depilation.
|
|
Enzyme unhairing
|
Loosening of the attachment of
the hair or wool of a hide or skin by treatment with an enzyme
preparation.
|
|
Enzyme-treated wool
|
Wool obtained by immersing woolled
skins, or pieces, in an enzyme solution to loosen it.
|
|
Epidermal
|
Appertaining to the epidermis.
|
|
Epidermis
|
Outer non-sensitive and non-vascular
layer of the skin of a vertebrate that overlies the dermis.
The epidermis is made up of superimposed layers, and whereas
the principal constituent of dermis is collagen, that of the
epidermis is keratin.
The two proteins are of very
different composition, and respond very differently to treatment
with unhairing solutions. When skin is limed the epidermis is
decomposed, thus enabling removal of the hair, whereas the underlying
collagen is not adversely affected.
|
|
Epithelial tissue (epithelium)
|
Tissue of the kind that covers
the surface of the body and lines some hollow structures in
humans and animals, consisting of sheets of cells bound closely
together without intervening connective tissue.
Epithelium may be protective
(for instance skin), absorptive or secretory (for instance glands).
It may produce special outgrowths (hairs, nails, horns etc.),
and for such purposes it may manufacture within itself
chemical material best suited for the purpose (for instance
keratin).
|
|
Equalisation
|
The mixing of effluents through
agitation or other means, in order to balance variations in
composition, pH, temperature and density prior to subsequent
treatment.
|
|
Equalise (v); equalising
|
See: Level (v); levelling.
|
|
Ester
|
Chemical compounds of alcohols
and acids used as solvents or diluents in finish formulations.
|
|
Ether alcohol
|
Chemical compounds of different
alcohols used as solvents in finishing formulations. Note: (ethyl
alcohol [ethanol]).
|
|
Ether alcohol ester
|
Chemical compounds of different
alcohols and acetic acid used as solvents in finishing formulations.
|
|
Ethylene Diamine Tetra Acetic Acid (EDTA)
|
Ethylene Diamine Tetra Acetic
Acid (EDTA), or its water soluble di- (Na2EDTA) or
tetrasodium (Na4EDTA) salts, are complexing agents
that can combine by co-ordinate bonding with a single metal
atom to form a cyclic structure called a chelation compound
or simply a chelate.
Chelating agents based on EDTA,
or its salts, provide a means of manipulation and controlling metal ions that have undesirable properties
by converting them to stable complexes which are not deleterious.
The suppression of certain properties of a metal without removing
it from the system or phase is called sequestration. EDTA is
a sequestrant, and the largest single use of sequestration is
the control of water hardness (water softening).
Application in the tannery: water
softener, metal stains removal, dung removal, stain prevention,
inhibition of incrustations, inhibition of proteolytic activity
causing grain ‘enamel’ damage in modern low-salt
preservation methods; avoidance of red-heat in storage.
|
|
Eugenics
|
Eugenics, the science dealing
with factors that influence the hereditary qualities of a race
such as growth rate, body size at mature age, composition
of cows milk and ways of improving these qualities.
Note: The formation and improvement
of utility breeds of
the larger mammals based on selection and planned matings.
|
|
European Norm (EN)
|
Norm or method set
up and approved by a European
Committee and accepted by the national Standards Bodies of the
EU countries.
|
|
Eutrophication
|
Enrichment of the water by nutritive
salts, particularly nitrogen and phosphorus compounds, favouring
algae growth.
|
|
Evenness
|
Attribute of a dyed material
showing a regular, level and equal colour all over its surface.
|
|
Excess salt
|
Conventional - pack - salt curing
is an effective but relatively inefficient process since more
than 50% of the salt offered remains as excess used salt.
|
|
Exhaust air
|
Gas or steam produced during
leather manufacturing. Mainly used to describe the exhausted
air from finish application systems.
|
|
Exhausted dye
|
Total removal, more or less,
of a dye from a bath to the leather being treated.
|
|
Exotic leather
|
Tanned and finished reptile or
batracian skin showing its original grain structure.
Note: Crocodile/alligator, snake,
etc.
|
|
Extensibility
|
Capability of a material
to be stretched or distorted without breaking.
Also the amount of
extension at the breaking point.
|
|
Extract
|
Liquid or solid obtained by leaching
a complex mixture with a solvent, such as water, in which certain
components are soluble and others insoluble, and evaporating
off the solvent.
Note: Concentrated aqueous extraction
products of the vegetable tanning materials.
|
|
Extract tanning
|
Tanning process based solely
upon the use of tanning extracts, in contrast to a process also
utilising ground vegetable tanning materials.
|
|
Extractable fatty matter
|
Fatty matter capable of extraction
(in Soxhlet apparatus) from leather, by certain organic solvents
such as dicholoromethane.
|
|
Extraction
|
Removal of polluted air by mechanical
or physical means. Local exhaust ventilation should be designed
to ensure that solvent fumes (VOC’s) are drawn away from the
point of origin and do not enter the breathing zone of the operator.
|
|
Extraction hood
|
Equipment under which the operator
works with toxic vapours. These vapours are extracted through
this equipment.
|
