Claire Fontaine - papeterie

PAPER VOCABULARY

Abrasion, resistance of paper to

Measures the loss of weight due to the friction of a grinding wheel on the surface of the paper. This test is an indication of the dusting which may occur when the paper is used. Clairefontaine papers' resistance to abrasion is four times lower than current standards.

Abrasiveness (Dennison wax)

Gives the abrasive character of the paper and thus the wear and tear on tools used during conversion or use of the paper. The test consists in evaluating the weight loss of a blade used to cut the paper. Clairefontaine papers are not abrasive, thanks to the very pure mineral filler used in their production.

Absolute humidity

It is the percentage of water contained in the paper. Usual values range from 4 to 7 %. It is calculated from the loss of weight after drying at 105°C.

Air permeability

It is the aptitude of paper to let air through.
The measurements are AFNOR, BENDTSEN and GURLEY.
AFNOR and BENDTSEN : the higher the measurement, the higher the permeability of the paper.
GURLEY : the higher the measurement, the lower the permeability of the paper.

AOX

"Absorbable organic halogens". X means halogen, usually chlorine. This term indicates the total quantity of organic chlorine in the pulp mill's effluent after production of the pulp used for the paper in question.

APUR

(Association of Producers and Users of recycled papers and boards) This association created a name which it manages and controls. It is a registered name with a charter of use: the logo on the product clearly indicates the proportion of recycled fibres used and the approval number corresponding to each range of paper or board, and which is a guarantee of the authenticity of the information given to the consumer.

Blue Angel

Label defined by the German federal environmental agency. The Blue Angel label is awarded to papers which do little damage to the environment. The paper is controlled in detail: its composition, its production process and its conversion. Only papers made from 100 % post consumer waste paper are certified.

Breaking length

It is a certain length of paper beyond with a strip of paper when hung up tears under its own weight.

Brightness (see also whiteness)

The colour measurement system usually used defines three values :

• L* Brightness
• a* green-red index
• b* blue-yellow index

The perception of the whiteness of a paper is affected by two parameters :

• shade : a bluish paper seems whiter
• brightness ; it is the sensation of lightness reflected by the paper

A bluish paper is often not very bright. The use of PCC (precipitated calcium carbonate) allows for a higher brightness with a bluish hue.

Bulk

This is the volume of the paper, or the opposite of density. It is the thickness in microns divided by the substance is gsm.

Burst strength

The Mullen burst ratio is the pressure needed for a membrane inflated against the surface of the paper to break the paper. It is a number of kilopascals (kPa) divided by the substance of the paper in gsm.
E.g. : Burst pressure: 250 kPa
      Substance: 75 gsm
      Ratio: 3.33 kPa.m2/g

Calcium Carbonate

This mineral filler is used in paper mills whose machines are run in a neutral medium. It is used under different forms :

• GCC : ground calcium carbonate, or quarry carbonate,
• PCC : precipitated calcium carbonate, made by adding carbon dioxide to lime
The latter has the advantage of having a higher whiteness, a higher opacity and a higher bulk.

Clairefontaine is the first paper mill in Europe to have installed its own PCC production plant in January 1992

Chain of custody (COC)

In order to have some signification, a forestry certification must be accompanied by a COC certificate which guarantees that the product sold contains a minimum quantity of pulp from certified forests.
Forestry developers have their forest management and their chain of custody certified. Firms doing secondary conversion (carpentry, pulp and paper production) have their chain of custody certified.

Chlorine

Is one of the halogens (along with fluorine, bromine and iodine). It is virtually no longer used under its elementary form (gaseous chlorine) for pulp bleaching). Chlorine dioxide, CIO2, which generates much less AOX, has replaced it in most pulp mills.

Coating

This operation can be done on or off the paper machine. A coating made up of mineral filler plus different bonding agents and additives is deposited on the surface of the paper. The weight deposited can be up to 25 gsm

Colour

The coloured perception obtained by an observer when a paper is observed under certain lighting conditions. Colour is quantified in different systems of three dimensional representation in space :
L, a, b – L, c, h – x, y, Y...
See also metamerism

Deinking

This operation removes the ink from printed paper in order for it to be recycled. The paper is generally treated with soap, and the inks which then float on the surface are recovered. Deinked fibres are often less white and less pure than virgin fibres.

ECF (see AOX and Chlorine)

Paper made from pulp which has been bleached using chlorine dioxide. Literally "elementary chlorine free" or chlorine gas free. From an ecological point of view, ECF pulp has a lower AOX rate than pulps bleached with chlorine gas.
It is nowadays considered that ECF and TCF pulp mills have the same impact on the environment.

Felt side / Wire side

Especially on flat bed paper machines, the paper can be asymmetrical because the water is drained through one side of the sheet. The wire side, which is the side where the water is drained is usually poorer in mineral filler and in fibres, and tend to be slightly less smooth.

Fillers

These are mineral product added to the paper to improve whiteness and opacity. These fillers are usually : talc, china clay or calcium carbonate. They are present either in the mass or on the surface (by coating or by pigmentation)

Flat bed (paper machine)

A traditional paper machine on which the sheet is formed by draining on an endless horizontal wire. This draining system is sometimes made more symmetrical by adding a former. A former is a second wire which removes the moisture from the top side of the sheet by suction.

Fluorescence (see optical brightener)

It is the property of a colouring agent which absorbs ultra violet rays (350 to 400 nanometres) and restores them as blue radiations from 420 to 500 nanometres. The average eye has a visible scope from 400 to 700 nanometres.

Forestry certification

This type of certification has been brought to the forefront because of demands of compatibility between forest exploitation and sustainable development. It can be awarded by independent bodies with very similar criteria. Two main schemes are recognized worldwide: PEFC and FSC.

Formation

This word indicates a good distribution of the fibres within the sheet. Good formation increases the opacity of the sheet, and its behaviour during printing.

FSC (Forest Stewardship Council) (see forestry certification and chain of custody)

Independent NGO having developed a certification system aiming for an adapted forest management, from an environmental social and economical point of view.

 

Global Compact

This policy aims to allow all people on our planet to benefit from the advantages of globalization and to anchor world markets to essential values and practices in order to satisfy socio-economical requirements.
This policy, instigated by Kofi Annan, general secretary of the UN, implies the adherence to 10 principles which should be put into practise in the company environment. The principles are in the areas of:

• Respect of human rights
• Respect of freedom of association and the right to collective bargaining
• Promotion of greater environmental responsibility
• Work against corruption in all its forms

Exacompta-Clairefontaine and Papeteries de Clairefontaine have individually adhered to the Global Compact.

Gloss

The aptitude of paper to reflect light in a certain direction. A ray of light is directed onto the surface of the paper at a precise angle (60 or 85 °) and the light which is reflected at the same angle is measured.
The higher the quantity of light reflected, the brighter the paper.

Hardwood pulp

Paper is made up of cellulose fibres, which are the main components of wood. Hardwood pulp, which comes from trees such as eucalyptus, birch, beech, aspen ..., contains short fibres. They are approximately 1 mm long, and improve the formation, the softness and the printability of the paper.

Lignin

Lignin is the main component of wood. It represents from 20 to 30 % of the carton of the whole plant biomass. After cellulose, it is the second organic component of the biosphere and is an abundant and renewable natural resource.
It helps plants remain upright despite gravity and the action of the wind. It also contributes to supplying them with water and mineral salts.
Lignin has the disadvantage of colouring under the action of light, and of contributing to the progressive acidification of paper.
It is however essential in giving mechanical qualities to timber.

Machine direction / Cross direction

The fibres are orientated in the same direction as the running direction of the paper machine.
This give non isotropic papers. A perfectly isotropic paper is square.

Metamerism

Is said of two colours which seem identical under one sort of lighting but which are in fact different. Analysis by spectrocolorimeter shows that these colours have different light reflectance curve lines which intersect in several places.

Mullen (see burst strength)

Opacity

The opposite of transparency. Opacity is defined by measuring the reflectance of a sheet of paper on a black background, then the reflectance of the same sheet on a certain thickness of paper when the fact of adding one extra sheet no longer changes the measurement.

Optical brightener

A colouring agent present in the paper, whose fluorescence increases the whiteness level of the paper and reduced the dominant yellow of the pulp, this giving a high impression of whiteness.

Paper pulp

This is the main constituent of paper, and comes from two main wood families :

• softwood pulp : long fibres giving solidity and mechanical characteristics to paper
• hardwood pulp : short fibres giving formation and softness to the paper

Pulp is made up in varying proportions of cellulose fibres and residual lignin (the skeleton of wood) :

• high yield thermo-mechanical or chemi-thermo-mechanical pulps, contain a high percentage of lignin and therefore have a bad level of light stability and yellow easily
• chemical pulps which are chemically cooked (kraft or bisulfite) which dissolves the lignin. The pulp is then bleached using chlorine, chlorine dioxide, hydrogen peroxide or ozone.

PCC (precipitated calcium carbonate)

This mineral filler, which is used in a neutral or alkaline medium, is not extracted from a quarry, but is produced by the reaction of carbon dioxide on lime.
Its advantages are very high opacity, bulk, and whiteness, with a lower abrasiveness than quarry calcium carbonate.
CLAIREFONTAINE was the first European mill to use this filler for the production of its writing and printing papers, as early as 1992.

PEFC (Program for Endorsement of Forest Certifications)

This independent NGO has developed a set of criteria to be satisfied in order to promote sustainable forest management. National forestry certifications which satisfy these criteria can in turn be PEFC certified.
This is the case for SFI, CERTFOR Chili and CERFLOR Brazil. PEFC criteria are similar to FSC criteria.
See FSC, forestry certification

Permanence

Papers made since the end of the 19th century in an acid medium deteriorated quickly and it was necessary to develop papers guaranteeing good conservation over a period of time. There is an international norm which applies to woodfree papers.
The ISO 9706 international norm defines the conditions for producing "permanent" papers.
A paper which fulfils these criteria can be stocked for many years under archival conditions (temperate medium and protected from light).
All Clairefontaine papers are in conformity with the ISO 9706 norm.
Furthermore there is also the German DIN 6738 norm which can be applied to all papers.
Under the DIN 6738 norm, longevity is classified under the following categories :

• CL 24-85 : these papers can be described as ageing-resistant,
• CL 12-80 : the lifespan of these papers is of several centuries,
• CL 6-70 : the lifespan of these papers is of at least 100 years,
• CL 6-40 : the lifespan of these papers is of at least 50 years.

However in the German introduction to the ISO 9706 norm, there is a clear restriction concerning the DIN 6738 norm : "The task of archives, libraries, museums and other collections is to conserve documents on a long lasting basis". That is why printers and editors should take care to respect the requirements of the ISO 9706 norm. DIN 6738 is valid for books which will predictably be destroyed after use.

pH (Hydrogen potential)

In chemistry, this value defines acidity. pH < 7 : acid medium,
pH = 7 : neutral medium (for example pure water),
pH > 7 : alkaline medium.
Neutral or alkaline papers have a longer lifespan. For more than 30 years, CLAIREFONTAINE has been producing neutral papers.

Pick (Dennison wax)

Measures the surface cohesion of the paper. Small sticks of wax of increasing adhesion are stuck onto the surface of the paper.
After cooling, they are removed, and the number of the strongest wax stick which does not pick the surface of the paper is noted.

Pigmentation

During paper production a light coating of mineral pigments is deposited on the surface of the paper by the size press. See size press

ppm (part per million)

This unit is used for low concentrations of a particular product.
A ppm of a tonne is a gram.

Recycled

It Is said of a paper containing recovered fibres as opposed to virgin fibres.
It is important to differentiate between pre-consumer and post-consumer recycled papers.
Pre-consumer recycling indicates paper which comes from intermediary scrap during the production process and which has never reached the final customers.

Relative humidity

This value is easier to obtain that absolute humidity. It is the percentage of water saturation of air which is in equilibrium with the paper.
For example it is said that paper with 6.5 % absolute humidity is in equilibrium with air at 23°C and 50 % relative humidity.

Roughness

See Smoothness

Size-press

A piece of equipment on the paper machine, just after the first drying section. The size-press deposits on the surface of the paper a coating of starch (surface refining) or a coating of mineral fillers plus a bonding agent (pigmentation).
The sizing of the paper is also improved by often adding at this point a hydrophobic agent.

Sizing

A product is added to the paper either in the mass or on the surface. This product eliminates the hydrophilic characteristic of the cellulose, and therefore permits writing and printing without ink penetration or loss of definition. Sizing is measured using two different methods :

• ink sizing : a series of lines are traced on the paper using increasingly aggressive inks (1 to 5). For each side of the paper the number of the ink which does not bleed or run is noted
• Cobb sizing : For each side of the paper the amount of water absorbed in noted after 1 minute of contact.

Smoothness

It defines the surface of a paper. It is the opposite of roughness .
It is determined by micro-analysis (surface profile, micro-contour test) of by macro-analysis (Bekk, Bendtsen, PPS or Sheffield, which measure the air flow between the surface of the paper and a metal or glass surface applied to it).
Bekk : measures the time necessary for the loss of a given volume
Bendtsen, PPS and Sheffield: measure the rate of loss under a constant pressure.

Softwood pulp

This come from trees such as pine, fir, spruce and contains long fibres. They are 2 to 4 mm long and give the paper its mechanical qualities such as tear, traction and burst resistance

Stiffness

It measures the resistance of paper to bending.
Two methods measure this characteristic in a different manner :
TABER, static method : measures the force necessary to bend a sample of paper from a give angle.
KODAK, dynamic method : measures the length of resonance of a paper samples. This depends on the stiffness and the substance of the paper.

Surface resistivity

This is an important characteristic for copier papers, resistivity is the opposite of conductivity. Resistivity is the resistance to an electric current when two different points on the surface of the paper are subjected to a tension difference (usually 100 volts).
If resistivity is too weak then there can be a loss of density of black printing.
If resistivity is too high then the build up of static electricity can cause paper jams.

Sustainable development

The concept of sustainable development was propagated in 1987 by the report "Our Common Future" of the United Nations' World Commission on Environment and Development (Brundtland report). This formulation, which aims to reconcile economic development and conservation of natural resources, sets out to be "a development which replies to the needs of the present without compromising the capacity of future generations to reply to their own needs".

TCF (totally chlorine free)

It is said of a pulp produced and bleached without using gas chlorine gas or chlorine derivatives.

Tear strength

The resistance of paper to tearing is given in millinewtons or in grams.
It is defined as being the average strength needing to be exerted in order to continue tearing the paper at the point where an initial cut has been made.

Twin wire (paper machine)

Paper production process where the paper is drained symmetrically between two wires.
This technique prevents the paper from becoming asymmetrical (the side of the paper through which the water is drained tends to contain fewer fine elements ( mineral filler, fine fibres).
See also flat bed, wire side, felt side Clairefontaine produces all its papers on twin wire machines.

Whiteness

The aptitude of paper to re-emit light received under the whole of the visible spectrum.
The most frequent measurements are ISO and CIE:

• ISO whiteness : measures the reflectance of the paper at 0.457 µm. This measurement depends mainly on the fluorescence of the paper (the quantity of optical brighteners) and very little on the shade of the paper
• CIE whiteness: measures the whole of the visible spectrum and is a better judge of the visual perception of the whiteness of the paper. It advantages bluish papers

Wood

Papers "with wood" are papers which contain significant quantities of high yield pulp, from which the ligneous part of the wood was not eliminated during pulp production.