Paper Industry Glossary |
Absorbency |
The extent to which a paper
will take up and hold a liquid. |
Additive |
A mineral, chemical or dye
added to pulp and coatings to give it special qualities such as opacity. |
Binder |
The adhesive used to stick
the layer of coating together and to the paper or board surface; the most
frequently used binder is starch but synthetic binders are also used to give
improved performance. Synthetic binders are generally described as latex. |
Biodegradable |
A substance which will
decompose as the result of action by bacteria and other living organisms. |
Blotting
paper |
Highly absorbent paper which
is sometimes watermarked; the ball point pen has drastically reduced the
demand for this type of paper. |
Board |
The papermaker's name for
cardboard; it is thicker and heavier than paper and may be made of several
layers laminated together. |
Calendered |
Paper which has been
smoothed and polished between sets of rollers called a calender; this
process is usually done at the dry end of a papermaking machine. |
Carbonless copy paper |
This consists of two sheets
of paper; the underside of the top sheet is coated with colourless dye in
tiny gelatine capsules; the underneath sheet is coated with a reactive
chemical which turns blue or black when mixed with the colourless dye;
pressure from a pen or typewriter on the top sheet causes the gelatine
capsules to break, the dye and chemical mix and the blue or black copy
appears on the bottom sheet. |
Carbon
paper |
A thin tissue paper coated
on one side with colouring agent or carbon black which is transferred to a
sheet of paper underneath when pressure is applied. |
Carton |
A container usually made of
board but sometimes partially or totally of plastic; it is delivered by the
carton manufacturer to the user in either flat or collapsed form. |
Cartridge paper |
Tough, slightly rough
surfaced paper used for a variety of purposes such as envelopes; the name
comes from the original use for the paper which formed the tube section of a
shotgun shell. |
Cases,
corrugated |
Large boxes made of board
which are used as containers for packages; cases are mainly used for transit
and storage purposes. |
Coating |
A layer of minerals applied
to one or both sides of paper or board to improve brightness, gloss and
printability; the mineral most often used is china clay, hydrated aluminium
silicate, but calcium carbonate and titanium dioxide are also used; the
coating is held together and stuck to the paper by a binder. |
Container board |
Another name for corrugated
board used to make transit cases or corrugated cases. |
Contraries |
Unsuitable material found in
waste paper which must be removed from the pulp before making it into paper,
e.g. paperclips, string. |
Converter |
A firm that specialises in
converting reels and sheets of paper and board into packaging or finished
goods for sale to the public. |
Corrugated |
Board usually made up of a
number of paper layers laminated together; the middle layer is fluted during
the process and the outer layers, called liners, are glued to it to give a
sandwich-like finish. |
Cross
direction |
The direction, at right
angles to the machine direction across a sheet or web of paper; paper
expands about three times as much in the cross section as in the machine
direction. |
Dandy
roll |
The roll on the wet end of a
papermaking machine which is covered with a woven wire and carries a design
to form a watermark in wet pulp. |
Downcycling |
Each time cellulose fibres
are recycled they deteriorate slightly and become contaminated, so the new
product is of lower quality than the original product which went to form the
waste; the progressive deterioration of fibres means there is a limit to the
number of times they can be recycled, thus the term downcycling is used as a
more accurate description of recycling. |
Dry end |
The part of a papermaking
machine where the paper passes through steam-heated drying cylinders. |
Esparto
grass |
A grass naturally occurring
in North Africa which, when pulped, produces a bulky fibre for making good
quality paper; it was once a popular papermaking fibre. |
Filler |
A material such as china
clay or calcium carbonate which is added to make paper smoother and increase
opacity. |
Fourdrinier machine |
A papermaking machine that
forms the paper in a continuous sheet; it was named after the Fourdrinier
brothers who financed the first operational machine at the Frogmore Mill,
Hertfordshire, in 1803. |
Grammage |
The term used to denote the
weight of paper or board; the measurement used is the weight of a single
sheet of one square metre, expressed as gramme per square metre (g/mē). |
Greaseproof paper |
Paper which resists grease,
or prevents the fats found in some foods from soaking into it; the paper is
produced by prolonged beating in the pulp stage. |
Industrial Revolution |
The period after about 1760
during which the development of steam power and the invention of different
types of machinery made Britain the leading industrial country in the world. |
Integrated mill |
A mill which starts with
logs or wood chips and first produces wood pulp which it then processes to
make paper or board; there are only five integrated mills in Britain. |
Kraft
paper |
Paper made from a type of
chemical wood pulp; it may be bleached or unbleached and produces a strong
paper which is used for wrapping and packaging; the term comes from the
German word for strong. |
Laminate |
Overlay of sheets of paper
or board either with other paper or board or with other materials such as
plastic or metal foil to form a product with special qualities. |
Landfill
site |
An area set aside as a large
dump for rubbish; old quarries and marshland are often used for this
purpose. |
Lignin |
Non-cellulose material found
in wood and other cellulose plants; lignin in paper makes it weaker and more
inclined to discolour when exposed to light; in the chemical pulp-making
process most of the lignin is removed. |
Machine
direction |
The direction the wire mesh
on a papermaking machine is travelling; over 50% of the fibres position
themselves with their lengths parallel to this direction. |
Multi-ply board machine |
A machine in which a number
of plies of paper can be combined together in the wet state to produce thick
cardboard. |
Newsprint |
The relatively low grade
paper on which newspapers are printed; it is mainly produced from mechanical
pulp and recycled fibres. |
Opacity |
The property of a paper
which prevents light being seen through it, measured scientifically as the
amount of light reflected by the paper; in practice, in a paper with good
opacity the printing or writing on one side cannot normally be seen from the
other side. |
Packaging |
The paper and board used for
wrapping or packing goods. |
Papyrus |
An ancient writing material
made from the stem of the papyrus plant, an African reed. |
Plasterboard |
A type of board with a
centre layer of gypsum and outer layers of board, used in the building
industry. |
Pulp |
Chemical pulp - Pulp made
from wood chips by treating (cooking) with chemicals to separate out the
cellulose fibres and dissolve the lignin, etc. binding them together; it can
be bleached or unbleached. |
Ream |
A unit of measurement for
sheets of paper; normally 500. |
Reel |
A continuous length of paper
wound on a core. |
Reelup |
The final process in making
paper; after passing through the drying cylinders and, if appropriate, the
calender rollers, the newly made paper is wound on to a jumbo reel: this is
the reel up stage. |
Rice
paper |
Sometimes a material which
has the same appearance and purpose as paper, is called 'paper': rice paper
is an example; it is not paper, but the sliced and flattened pith of a plant
that grows in Formosa in Asia; rice paper is used by Chinese artists as a
surface for painting on. |
Secondary pulp |
Pulp made from waste paper
and not directly from wood. |
Security
paper |
Paper which includes
identification features such as metallic strips and watermarks to assist in
detecting fraud and to prevent counterfeiting. |
Service
industry |
That part of industry which
provides a service for others and does not manufacture goods, e.g.
transport, warehousing. |
Sizing |
This process can either be
applied on the surface of the sheet or in the sheet: in the first case
starch is applied to the surface to increase its strength and to resist the
penetration of oil-based inks (this process is carried out at the size
press, which is about two-thirds of the way down the dry end); in the second
case chemicals are added to the stock at the pulping stage before the sheet
is formed: this is called internal or engine sizing and its purpose is to
stop penetration of water-based inks into the sheet. |
Solid
cases |
Cases made of several layers
of board glued together; they have high puncture resistance and may be water
proof. |
Stampers |
The wooden hammers used in a
watermill to pulp rags in order to separate the fibres. |
Stock |
The wet pulp before it is
fed on to a papermaking machine, or during the papermaking processes before
it becomes a sheet of paper; contains around 99% water and 1% fibre. |
Tissue
paper |
Soft, lightweight paper used
for hygienic and household purposes. |
Urban
forest |
A description of towns and
cities which are the source of waste paper as one of the raw materials used
for papermaking. |
Watermark |
A deliberate design or
pattern in paper made by a dandy roll as the stock passes through the wet
end processes; a watermark can be seen by holding the paper up to the light. |
Wet end |
The first stages of a
papermaking machine before the drying process; at the wet end, stock is fed
in and much of the high percentage of water is eliminated by drainage,
suction and press rollers, leaving a web of paper which then passes to the
drying cylinders. |
Wood
free |
Paper made wholly from
chemical pulp and free from wood-based impurities, such as lignin, which are
present in mechanical pulp. |
Wove
paper |
Paper first made as early as
1754 by forming it on a mould with a cover made from woven wire cloth, hence
'wove paper'; the paper has no watermark and an even opacity; it is a type
of paper in common use today. |