|
Haematein
|
Red dyestuff, formed by the oxidation
of haematoxylin, which is contained as glucoside in logwood.
|
|
Hair
|
Keratinous fibres growing from
the skin of most animals, except certain types of sheep, characterised
by its stiffness, straightness and special surface pattern of
scales.
|
|
Hair bulb
|
Lowest part of the
hair inserted into the hide or skin.
See: Hair root.
|
|
Hair drying
|
Drying of hair recovered from
the unhairing.
|
|
Hair follicle depth
|
The depth of the rounded sack-like
structure which extends downwards into the thickness of the
dermal tissue. In this narrow- mouthed follicle the hair or
wool is developed and an attached sebaceous gland discharges.
The follicle depth is different in various body sites.
|
|
Hair immunisation
|
Reduction of the solubility of
hair in sulphides by means of an alkaline pre-treatment.
|
|
Hair looseness (slippiness)
|
Condition of the hair on a hide
or skin, brought about by bacterial action or a depilatory process,
such that it can be readily scraped away.
|
|
Hair loosening
|
Release of hair from the hide
or skin.
Note: During unhairing or because
of insufficient preservation.
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|
Hair pieces
|
Areas with hairs left on the
unhaired pelt.
|
|
Hair pore
|
More or less fine opening of
the hair follicle on the skin surface.
See: Grain pattern.
|
|
Hair recovery
|
Recovery of more or less whole
hairs during the unhairing process.
|
|
Hair root
|
Part of the hair below the grain
layer.
|
|
Hair save unhairing
|
Any method of unhairing in which
the hair is recovered more or less undamaged.
|
|
Hair screening
|
Elimination of whole hairs from
a liquid by the means of screening.
|
|
Hair shaft
|
Part of the hair above the grain
layer.
|
|
Hair sheep
|
Type of sheep having a coat of
straight, stiff, fibres instead of soft and curly, and occurring
in the higher, drier and more tropical regions, such as Africa,
India, Java, Brazil and the Middle East.
|
|
Hair slip
|
Hides
and skins which have undergone sufficient putrefaction to loosen
the hair or wool.
|
|
Hair washing
|
Washing of hair removed from
the unhairing.
|
|
Hair-on leather
|
Leather tanned without removing
the original hair in the beamhouse.
Note: Textile leather such as
picking band leather.
|
|
Halo
|
Halocarbon, halogenated
hydrocarbon, hydrocarbon containing one or more halogen atoms
(chlorine, fluorine) in the molecule. Note: CFC solvents.
|
|
Halotolerant bacteria
|
Class of bacteria that do not
require salt (NaCl) for growth but can tolerate salt and are
capable of growth in 20% salt environment. Halotolerant bacteria
are frequently equated with halophiles, a group of archaeobacteria
that require salt for growth.
|
|
Hammameli tannin
|
Crystalline degalloylhexose,
without tanning properties, isolated from the bark of Hammamelis
virginica.
|
|
Hammer (v); hammering
|
Process of striking repeatedly
with a hand or mechanically operated hammer, to consolidate
bottom leather, to flatten a welt after attachment or to shape
an upper to the last.
|
|
Hand boarded
|
See: Board (v); boarding.
|
|
Hand buffed
|
See: Buff (v); buffing.
|
|
Hand grained leather
|
See: Board (v); boarding.
|
|
Hand stuffing
|
Application of grease by means
of a pad or brush, to the surface of damp leather, spread upon
a table.
|
|
Handle
|
Sensation or feeling of certain
physical properties of leather, such as flexibility and smoothness,
which can be perceived by touch with fingers and hands.
|
|
Handle (v); handling
|
Removing hides or skins from a processing vessel or
liquor and replacing
them in the same or another vessel or liquor.
|
|
Hang (v); hanging
|
Suspend a hide from above by
means of one or more nails, hooks, strings, etc., through one
end or edge.
|
|
Hang drying
|
Drying method of leather, generally
under cover in a normal atmosphere with ventilation or with
the addition of warm air.
|
|
Hard grain goat
|
Goatskin leather with a characteristic
pinhead grain pattern, produced by hand boarding, after glazing,
in a damp condition in at least four directions. Vegetable tanned.
Note: Sometimes called Morocco.
In Germany also combination tanned and especially sumac tanned.
|
|
Hard resin
|
Synthetic resin which produces
a film, inflexible and not easily penetrated.
|
|
Hardened fat
|
Solid fat made by chemical reaction
(hydrogenation) from certain animal and vegetable oils.
|
|
Hardener
|
Agent in finish preparations
to assist film-forming or to improve the properties of a finish
by a hardening effect.
|
|
Hardness
|
Amount of calcium
carbonate dissolved in water, usually expressed as parts of
calcium carbonate per million parts of water.
|
|
Harness leather
|
Strong, flexible,
curried, cattle hide, grain leather with a plain finish, usually
having a thickness of 4 mm to 6 mm.
|
|
Hat leather
|
Sheep or calf leather, usually
vegetable tanned, specially prepared for the sweat bands of
hats or caps.
Note: Also termed "Hatband
leather".
|
|
Hat leather
|
Type of hydraulic leather moulded
in the shape of a hat.
|
|
Haul (v); hauling
|
Removing individually hides or
leather in process from a pit.
|
|
Hazardous wastes
|
Waste which can cause or significantly
contribute to an increase in serious irreversible incapacitating
illness or pose a substantial hazard to human health or the
environment because of its quantity, concentration or physical,
chemical or infectious characteristics.
|
|
Health and safety instruction
|
Instructions for a machine or
a process, intend to prevent injury to an operator.
|
|
Heat damage - (in paint)
|
Damage
to skins caused by temperatures rising which may be due to exothermic
reaction of the alkalis used, or if the paint solution is too
warm when applied.
|
|
Heat pump
|
Device for transferring heat
from a substance or space at one temperature to another substance
or space at a higher temperature. It consists of a compressor,
a condenser, an expansion valve, and evaporator. Is used in
raw sheepskins and leather drying.
|
|
Heating up - (in paint piles)
|
Elevation
of temperature in the middle of a pile of sheepskins that have
been painted with an
aqueous depilatory mixture.
|
|
Heavy metal
|
Metal whose specific
gravity is approximately 5.0 or higher (such as lead, copper,
chromium, nickel). The heavy metals content in wastewaters is
usually strictly limited by the environmental legislation as
well as in final goods asking for “ecolabel”.
Note: Lead, copper,
chromium, nickel.
|
|
Heel
|
Raised component
under the rear of the shoe consisting of any of a wide variety
of shapes, heights, styles and materials.
|
|
Helvetia leather
|
In Italy, Spain and the UK a
yellow, very tough, flexible, greasy, cattle hide leather, traditionally
salt and alum pre-tanned and then stuffed with a mixture of
fish and animal oils. The yellow colour is caused by oxidation.
|
|
Hereford hide
|
Hide of a breed of a hardy red
beef cattle with white faces and markings that originated in
Herefordshire, England, but are now extensively raised in the
Western USA and other grazing regions. The Hereford hide is
carrier of a genetic peculiarity associated with pure Hereford
breed; the fibres of the hide tissue are arranged in a parallel
manner nearly perpendicular to the grain surface.
See: Vertical fibre; cauliflower
effect.
|
|
Hide
|
The outer covering of a mature
or fully grown animal of the larger kind.
|
|
Hide powder
|
Powder from an untanned
or lightly chrome-tanned hide, used in the vegetable tannins
analysis.
|
|
Hide powder method
|
Method to evaluate
the tannins and non-tannins content in a liquid or a material
(in solution) by measuring the amount of matter bound by the
hide powder.
See: Filter bell.
|
|
Hide processor
|
More or less long and large diameter,
rotatable drum, inclined at an angle which may be fixed or variable,
with an open upper end for loading and unloading and with an
internal spiral blade system; used for treating hides or skins
with liquors.
|
|
Hide salt
|
Common salt of appropriate purity
and grain size for salting hides; sometimes denatured.
|
|
Hide substance
|
A way to express
the protein content in a leather.
|
|
Hide wringer
|
Machine for squeezing superfluous
liquor from prefleshed, brined hides by passing between rollers.
These hides are sufficiently ‘dry’ to be bundled immediately.
|
|
High frequency conditioner, dryer
|
Drying or conditioning unit,
mainly as through-feed process. It is possible to achieve accurate
moisture contents in the leather by means of electromagnetic
waves with very high oscillation frequencies.
|
|
High Performance Liquid Chromatography (HPLC)
|
Method used in chemical laboratory
to separate the chemical compounds of a chemical mixture. This
separation is carried out in a liquid phase at high pressure
in a column.
|
|
High Performance Liquid Chromatography – Diode Array Detector
(HPLC-DAD)
|
Same as High Performance Liquid
Chromatography, with a specific detector used to detect, for
example, such products as azo dyes.
|
|
High Volume Low Pressure (HVLP)
|
System used in spray finishing
of leather, based on a high volume of air at a low pressure
feeding the spray guns.
|
|
Hippy velour
|
Ragged-looking patchy or mottled
suede leather made from an unfleshed hide or skin, finished
on the unfleshed side.
Note: Also known as "Wild
suede".
|
|
HLB
|
See: Hydrophilic Lipophylic Balance.
|
|
Hogskin
|
Grain gloving leather made from
the skins of the peccary and carpincho and in Germany also the
domestic pig. This leather is sometimes buffed on the grain
and then is known as buffed hogskin.
|
|
Hold up
|
Poor hold
up refers to the appearance of the surface pigment finish. A
patchy appearance may
be caused by excessive penetration of the base coats.
|
|
Hole
|
Hole caused
by butchers when removing hides from the carcass. Also mechanical
damage holes. Note: Fleshing machine damage.
|
|
Hoof
|
Hard, horny casing of the foot
of certain animals such as
horses, cattle, deer, swine.
|
|
Horn
|
Permanent growth, often curved
and pointed and usually one of a pair, on the head of cattle,
sheep, goats and other mammals; it consists of a keratinous
sheath over a bony core.
|
|
Horn rake
|
Long narrow
surface lesion caused by the horns of cattle too closely herded
together.
|
|
Horse butt
|
Rear part of a horse hide obtained
by cutting from flank to flank at right angles to the backbone.
Note: A horse butt represents
about one-third of the whole hide.
|
|
Horse butt
|
Leather made from the rear part
of a horse hide.
|
|
Horse leather
|
Leather made from equine animals.
|
|
Hot pit (v); hotpitting
|
Used at the end of pit vegetable
tanning. A high strength liquor (17 °Bé to 18 °Bé ) with a raised
temperature of 40 °C to 43 °C which reduces
the particle size, allowing greater penetration and fixation.
|
|
Hot stuffing
|
Introduction of grease into leather
by treating in the dry or damp state with hot, molten grease
by surface application, drumming or dipping.
|
|
Hot water mark
|
Localised
area of hide or skin affected by hot water or steam pipe where
the collagen has partially or completely gelatinised.
|
|
Hot-air stuffing
|
Introduction of grease into leather
by milling it in a damp state in a drum heated by hot air.
|
|
HPLC
|
See : High Performance Liquid
Chromatography.
|
|
HPLC - DAD
|
See : High Performance Liquid
Chromatography – Diode Array Detector.
|
|
Humidity
|
Atmospheric water
vapour content expressed in any of several measures, such as
relative humidity.
|
|
Humidity controller
|
Device for controlling the moisture
content of the atmosphere in a system.
|
|
Hunting calf
|
Suede upper leather with the
suede on the flesh side, made from a larger calf skin or from
a veal.
Note: Somewhat coarser than suede
calf.
|
|
Hunting suede
|
Suede upper leather, finished
on the flesh side, made from calf skin, heavy goat or cattle
hide. See Hunting calf.
|
|
Husk
|
Dry, outer covering of certain
fruits or seeds, such as the seed pods of Teri.
Note: Caesalpinia digyna.
|
|
HVLP
|
See: High Volume Low Pressure.
|
|
Hyaline layer
|
Very thin, glass-like film, said
to exist between the Malpighian layer and the grain membrane.
|
|
Hyaluronic acid
|
Viscous mucopolysaccharide (glycosaminoglycans)
composed of acetylglycosamine and glycuronic acid units widely
found in animal tissues (for instance in synorial fluid, in
the ground substance of connective
tissue and in the vitreous tissue of the eye), as well as in
bacterial capsules.
|
|
Hydration
|
Incorporation of
molecular water into a complex molecule with the molecules or
units of another species; the complex may be held together by
relatively weak forces or may exist as a definite compound.
|
|
Hydraulic leather
|
Hide leather specially prepared
to be flexible enough for moulding to shape.
Note: Usually supplied in the
mellow rough tanned state but sometimes dressed or wax impregnated.
Also known in North America as
packing leather.
|
|
Hydraulic leather
|
Leather items made from hydraulic
leather, moulded to shape and impregnated with wax.
|
|
Hydraulic plating press
|
Obtain desired plating effect
and film formation of finished leather by high pressure from
a heated, polished steel plate.
|
|
Hydro-extractor
|
Centrifugal machine, with a perforated
inner cage, rotating at very high speed.
Note: Used to extract water from
skins.
|
|
Hydrogen Sulphide (H2S)
|
Colourless gas with characteristic
odour of rotten eggs, heavier than air and toxic when inhaled.
In the tanning industry, the liming liquor containing sulphide
is drained off and sent to the effluent treatment plant where
hydrogen sulphide gas may concentrate.
|
|
Hydrolysable tannin
|
Vegetable tannin of the class
which, in contrast to tannins of the condensed class, can be
split by enzymes (tannase), or dilute acid into simple units,
(glucose and phenolcarboxylic acids), such as gallic, digallic
and ellagic acids.
|
|
Hydrolysis
|
Decomposition or
alteration of a chemical substance by water.
In aqueous solutions
of electrolytes, the reactions of cations with water to produce
a weak base or of anions to produce a weak acid.
|
|
Hydrometer
|
Device for measuring some characteristics
of a liquid such as its density (weight per unit volume) or
specific gravity (weight per unit volume compared with water).
Hydrometers may be marked in any of
four scales: Specific gravity, Twaddle, Baumé, and Barkometer.
Specific tables show the relationship between BK, Tw, Bé, and
specific gravity and allow the conversion of the readings.
|
|
Hydrometer method
|
Method to evaluate
the concentration of, for example, vegetable tanning floats,
by measuring the density.
The density can be
expressed in different ways.
Note: g/v, Barkometer
degrees, Baumé degrees.
|
|
Hydrophilic group
|
Group which has affinity for
water.
|
|
Hydrophilic Lipophylic Balance (HLB)
|
Relative simultaneous attraction
of an emulsifier for two phases of an emulsion system. For example:
Water and oil.
|
|
Hydrophobic group
|
Group which has no affinity for
water, or repels water.
|
|
Hydrophobing
|
Rendering a material such as
shoe or garment leather, water repellent.
|
|
Hydroxyproline
|
C5 H9
O3 N. Amino acid that is essentially limited to structural
proteins of the collagen type.
|
|
Hygroscopic equilibrium
|
Equilibrium between the moisture
content of a material and the surrounding moist atmosphere.
|
