Glossary

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SANDWICH CONSTRUCTIONS - Also known as PIGGYBACK

Panels composed of a lightweight core material to which two relatively thin, dense, high strength faces or skins are adhered. Also refers to sandwich of pressure sensitive materials - two liners and a facestock. Facestock has adhesive, laminated to liner that also has adhesive and is laminated to the base liner. The resulting label is three part and can be used twice, and with NCR added to the adhesive, becomes a self copying label after the first image is impressed onto the face stock. Refer LM.

SATURATION (IMPREGNATION)

The addition of various materials such as latex or rubber to a face material so as to improve its various physical properties.

SCAN

The electronic search for a symbol which is to be optically recognised. A search for marks to be recognised by the recognition unit of an optical scanner.

SCORE

To make an impression or a partial cut in a material for the purpose of bending, creasing, folding or tearing.

SCORE CUT - See SCORE

SCORING - See SCORE

SCRAP - See WASTE

SCREEN PRINTING

A method of printing in which the ink is forced (squeegeed) through a design on a taut screen (fine mesh) onto the object to be printed. Usually in flat format, but now screen printing units are available for rotary type presses.

SCUFF - See RUB TEST

The action of rubbing against a surface with applied pressure. Also the damage which has taken place through rubbing. Refer NS, LM & IM.

SEALER - See BARRIER COAT

A coating designed to prevent the passage of a substance through a substrate; barrier coat.

SECOND SURFACE PRINTING

Refers to printing on another surface in addition to the primary surface.

SECONDARY LABEL

Sometimes smaller than a primary label with information covering ingredients, nutrition, instructions for use, cautions and warnings, prices, promotional advertising, rebates, etc.

SELF-ADHESIVE LABEL - See PRESSURE SENSITIVE LABEL

SELF-ADHESIVE PRODUCTS - See PRESSURE SENSITIVE LABEL

SELF-CHECKING

A bar code or symbol using a checking algorithm which can be applied to each character to guard against undetected errors. Non self-checking codes may employ a check digit or other redundancy in addition to the data message.

SELF-EXTINGUISHING

A somewhat loosely used term describing the ability of a material to cease burning once the source of flame has been removed.

SELF-WOUND

A roll of material with a single liner, which is coated on both sides with a release coating and a carrier having a pressure sensitive adhesive on both sides. Also a material that has pressure sensitive adhesive applied to one side and then rolled up on itself (no liner).

SELVEDGE

That part of the roll of pressure sensitive along the web, that does not have adhesive. Refer LM.

SEMI-AUTOMATIC

A labelling machine in which only part of the operation is controlled by the direct action of a human. The automatic part of the operation is controlled by the machine.

SEMI-GLOSS PAPER

Coated one sided lithography (litho) paper.

SEPARATOR - See PATTERN COATED

SERIAL CODE

A bar code symbol typically used with a fixed beam scanner where the scanning action is caused by the motion of the symbol past the scanning head. The bits of the symbol are evaluated one at a time as the symbol passes.

SERVICE TEMPERATURE

The temperature range that a pressure sensitive label will withstand after 24-72 hours residence time on the labelled surface. The range is expressed in degrees Fahrenheit and/or Celsius. Refer NS & LM.

SET

The point during the bonding process when the adhesive has reached such structural proportions so as to prevent the movement of the substrates surface.

SET-OFF

Improperly dried or cured inks or coatings that transfer to the back of the liner material either in roll form or sheet form. Refer NS, LM & IM.

SETUPS - See MAKEREADY

SHARPEN

To decrease in colour strength, as when half-tone dots are made smaller.

SHEAR - See COHESIVE STRENGTH

The relative movement of adjacent layers in a liquid or plastic during flow.

SHEAR CUT

Term that describes a cut of a continuous web of stock using an action similar to the action of scissors.

SHEAR RATE

Time required for breakdown of the shear strength.

SHEAR STRENGTH

The relative resistance of an adhesive coated film or paper to a stress applied in such a manner that the adhering surfaces slide in a plane parallel to their plane of contact; the internal or cohesive strength of the adhesive. Refer NS & LM.

SHEAR STRESS

Where normal stress is perpendicular to the designed plane, shear stress is parallel to the plane.

SHEAR TEST

A method of separating adhesive bonded materials by forcing the interfaces to slide over each other. The force exerted is distributed over the entire bonded area at the same time. Strengths are recorded in kilos per square centimetre, or in minutes or hours to failure. Refer NS & LM.

SHEET FED

Designates a printing press to which paper is fed in sheets rather than in rolls.

SHEET FORM

Pressure sensitive labelstock packaged in sheets, designed for use on a sheet fed press. Refer NS & LM.

SHEETING

A method of converting rolls of labelstock into sheets (usually A4 size with die cut labels positioned) on a roll label press.

SHELF LIFE

The period of time during which a product can be stored under specified conditions and still remain suitable for use. Normally 6-9 months. Also called storage life. Refer NS & LM.

SHELL CUP

A device for measuring viscosity.

SHELLAC

An alcohol soluble natural resin widely used in flexography inks.

SHORE HARDNESS

A method of determining the hardness of a material using a scelroscope.

SHRINK WRAPPING

A method of packaging where labels are overwrapped with a heat sensitive polymer or cellophane shrink film and then passed through a heat tunnel to shrink the film tightly against the labels.

SHRINKAGE

Reduction in any dimension.

SIDE ROLL - See OFF-CUT

SILICONE

A polymer of organo-siloxane used as an ink additive to aid ink flow out. Also used for pressure sensitive adhesives capable of withstanding extreme temperatures. A polymeric material with exceptionally high repellency properties towards adhesives, and used extensively in the coating of release liners. Refer NS & LM.

SILICONE ADHESIVE

Adhesive compounds of this base have remarkable stability through a wide temperature range. Chief limitations for present use are their high temperature cure, and sensitivity to aliphatic and aromatic fuels; pressure sensitive adhesive which permits bonding to difficult surfaces; outstanding high temperature and low temperature performance; highly resistant to oxidation, ozone and corona radiation and has good dielectric properties. Refer LM.

SILICONE COATING

A unique polymer system which can be a very effective release coating.

SILICONE STAIN TEST

A water based stain used to test silicone coating coverage and continuity on the die cut paper release liners.

SINGLE FACED

Where adhesive is applied to one side of a carrier, as in self-wound laminating films and tapes.

SIZE - See PRIMER

SIZE PRESS

Section of paper machine where surface treatments, such as a starch solution, are applied to the paper to give it special qualities.

SKELETON - See MATRIX

SKID

Wooden or plastic platform on which most materials are now shipped. Not usually a full sized pallet, but undersized in height from the ground.

SKIPPING

Missing print, tints or coatings on a substrate due to dry-in of ink or coatings in the cells of the anilox roller.

SKIPS

Areas wherein the adhesive or the release coating are missing from the lamination.

SLIP ADDITIVE
Additive to inks or varnishes to effect improved slip or lubricating qualities.

SLIP SHEET OR INTERLINER

Interleave layer of material utilised to assist converting thin, unmanageable materials. This layer is later removed.

SLIT

To cut rolls of labelstock to specified widths. Either rotary (scissor action) or Stationery (razor or air) knives or blades are used with mechanical unwinding and rewinding devices that are controlled to ensure that correct tracking and tension of the roll from the master reel to the converted widths takes place. Most Labelstock converters purchase their stock - pre-slit by the Labelstock Manufacturers.

SLIT BACK - See SPLIT BACK

SLIT FACE - See SPLIT FACE

SLITTER

A machine to cut roll labelstock in the long direction and rewind onto useable core diameters. Three types are used: 1> Razor blade slitter. 2> Shear slitter 3> Score slitter

SLOT

A cut made in a material of a specific size and location. May have the face material removed when used to feed through imprinters.

SLUG

Old term - a strip of linotype or Ludlow (printers’ type letters in one piece - lead). New term - small piece of flexographic printing plate used to print variable information.

SMOOTHNESS TEST

The relative smoothness of paper is determined in a precision instrument which, under closely controlled circumstances, measures the length of time for a specified volume of air to pass the surfaces of the samples being tested. The result is expressed in seconds and fractions thereof.

SMUDGE RESISTANCE

Resistance of a printed paper surface to ink blurring or smearing and thus related to the absorption of the paper. Refer NS, LM & IM.

SOFT DOT

A dot is referred to as ‘soft’ when the halo surrounding it is excessive and almost equals the area of the dot itself.

SOLIDS CONTENT

The percentage weight of non-volatile components in an ink, coating or adhesive.

SOLVENT

A chemical substance capable of thinning or reducing the viscosity of ink, coating or adhesive. Specifically, a solvent is a liquid that dissolves another substance.

SOLVENT ADHESIVE

Adhesive components that are dissolved in a variety of organic solvents for coating. Rubber or acrylic based systems can be coated this way. Refer LM.

SOLVENT-FREE

The absence of any solvent in an ink, coating or adhesive.

SOLVENT RESISTANCE

The resistance of a pressure sensitive label to the action of specific organic liquids. May apply to either adhesive, printing or the labelstock. Refer LM & IM.

SOLVENT RETENTION

The solvent that remains in the adhesive or ink. If the adhesive is not thoroughly dried, solvent retention could reduce the efficiency of the adhesive. If all the solvent is not removed from the ink, the retentive portions will tend to keep the ink soft. Refer LM & IM.

SOLVENTLESS SILICONE

A silicone release coating applied without the use of any organic solvent or water. Also known as 100 percent solids silicone. Refer LM.

SPACE

The lighter element of a bar code formed by the background between bars.

SPECIFIC ADHESION

The force required to remove a pressure sensitive adhesive from a specific product under specified conditions. Also the relative tendency of adhesives to form bonds on specific surfaces. Some may be permanent on one surface and removable from another. Refer NS & LM.

SPECIFIC GRAVITY

The ratio of the weight of a specimen to the weight of an equal volume of water.

SPLICE

A method of joining webs to produce an operational continuous web. Refer NS & LM.

SPLIT BACK

Slits in the release liner to facilitate its removal by hand.

SPLIT FACE

Slits in face of pressure sensitive product usually for the purpose of facilitating removal from the release coated backing (liner).

SPLIT LINER - See SPLIT BACK

SPOT LABEL

Label that does not extend completely around can or bottle. Usually confined to less than half the circumference.

SPOT VARNISH - See PATTERN VARNISH

SPREAD

The enlargement of a printed image from a printing plate to the printed image. Also a photographic spread of artwork to achieve required ink bleeds or traps.

SPREADS AND CHOKES - See CHOKES and SPREADS

SPUNBOUND OLEFIN

Describes a synthetic plastic material formed by the random distribution of very fine continuous fibres which are selfbonded by heat and pressure.

SQUEEZE-OUT

The flow of excess adhesive or coating when pressure is applied. Can be caused by very tightly wound rolls of labelstock or converted labels. Refer NS & LM.

STABILISE

To increase the steadiness of a film, keep it from changing or fluctuating. Usually vinyl films are stabilised by laminating a polyester to one or both sides of the vinyl.

STABILISED KRAFT

Term used to describe paper that is treated to provide moisture resistance and dimensional stability. Refer NS & LM.

STABILISER

An ingredient used in formulation of some plastics, especially elastomers, to assist in maintaining the physical and chemical properties of the compounded materials at their initial values throughout the processing and service life of the material.

STACK PRESS

Flexographic press where the printing stations are placed one above the other, each with its own impression roller.

STACKER

Device on the tale-off end of a press that automatically stacks sheeted or single labels.

STAIN RESISTANCE

The ability of a label to be applied to a surface without discolouring that surface. Also the ability of a printed label to resist staining due to exposure to the product being labelled.

STAINING

A discolouration of a surface caused by adhesive residue.

STANDARD CONDITION

The condition reached by a specimen when it has attained equilibrium under a specified temperature and humidity; usually 73 F +/- 2 degrees and 50 +/- 3% RH.

START/STOP CHARACTER

A bar code character that provides the scanner with start or stop reading instructions as well as code orientation. The start character is normally at the left hand side end of a ‘picket fence’ oriented code. The stop character is normally at the right hand end.

STATIC

Electrical charges generated when handling materials which cause those materials to cling together. Static charges can jump (earth) to humans or equipment causing shock or fire if solvent is present. With reference to films, static causes them to cling to one another or to other insulating surfaces.

STATIC ELECTRICITY

A build-up electrical charge on the surface of a substrate or other surfaces, usually induced by friction and usually under low atmospheric humidity conditions.

STATIC ELIMINATOR

A device for neutralising static electricity.

STATIC NEUTRALISER

On printing presses, it is an attachment designed to remove static electricity from paper to avoid ink set-off and trouble with the feeding of the paper. On flexographic presses, static can cause problems when sheeting takes place at the delivery end of the machine.

STEEL-TO-STEEL LABEL - See ANVIL CUT or SHEETED LABELS

STEP AND REPEAT

The act of or equipment for the positioning and exposing multiple complete images onto film in preparation for plate making. ie. If a job is printed 16 up (2 across web x 8 down) and positioned to fit a die, then to prepare one image 16 times in registered position is called to ‘step and repeat’.

STEPPED ANVIL - See UNDERCUT ANVIL

STICK

To stick. Designating adhesion or stickiness (tack).

STICKYBACK

Double faced adhesive coated material used for mounting printing plates to the cylinder, or flat-bed cutting dies to the platen. Refer NS & LM.

STIFFNESS

The measure or degree of resistance to bending stress of a material.

STOCK

Paper or other material to be converted. Also called substrate.

STORAGE STABILITY

The ability of a material to be stored under normal conditions of temperature and humidity without change in its properties. Refer NS & LM.

STRETCH/SHRINK FACTORS

Calculations of dimensional change which occur in rubber plate moulding and mounting and photopolymer plate mounting when applied to the plate cylinder.

STOCHASTIC (Screening) - Also known as Crystal Raster and Diamond Screening.

Non conventional screening. No moire pattern and the dot is measured in microns. There is no set pattern or angle to the screen, and the plates are used to increase detail and give a sharper image to a screen image. Usually utilised with four (4) colour tone printing.

STRIATION

A fine streaky pattern of parallel lines, usually in the cross direction of the web travel.

STRIKE-THROUGH

The penetration of the adhesive or ink through the substrate.

STRINGINESS

A condition of the adhesive in which it feels very soft and mushy, and on close examination relatively ling ‘strings’ of adhesive can be pulled out of the adhesive.

STRIP COATED - See PATTERN COATED

STRIPPED

When separate pieces of film are taped together to create the complete printing image. Also refers to die cut labels from which the matrix has been removed.

STRIPPER PLATE - See PEELER PLATE

STRIPPING

The removal of the face material (usually with the adhesive) outside and around the die cut shape of the label, around a roller which assists the matrix on its way to be re-wound.

STUB ROLL

A short roll of face material or pressure sensitive label stock.

STYRENE - See POLYSTYRENE

A liquid unsaturated hydrocarbon (C8H8).

SUBSTRATE

The surface to which a label is applied, adherend. Converters also refer to the face stock being printed as the substrate. Refer NS & LM.

SUBSURFACE PRINTING

Printing the underside of a transparent film. Ultimately the ink will be sandwiched between the film that was printed and the film or surface to which it is applied.

SULFITE

Acid process of cooking pulp. Also the pulp cooked by this process.

SUNLIGHT RESISTANCE

The ability of a material to resist the deteriorating effects of sunlight especially those wavelengths in the ultraviolet and the Infrared ends of the spectrum. Refer IM.

SUNLIGHT RESISTANT ADHESIVE

An adhesive which contains an inhibitor to resist destruction by ultraviolet rays. Refer LM.

SUPER CALENDER (Paper)

A calender stack used to alter the surface properties and appearance of a paper. It is constructed on the same general principle as a calender, except that alternate chilled cast-iron and soft rollers are used in the super calender. The soft rollers are constructed of highly compressed cotton or paper. It is not part of the paper machine, whereas the regular calender stack is.

SURFACE COATED (Paper)

A term applied to any paper which has one or both sides coated with a pigment, clay or other suitable material. Refer LM.

SURFACE PREPARATION

The physical and chemical methods used to prepare a surface for further processing.

SURFACE RESISTIVITY

The electrical resistance of a material between the two opposite points of a unit of its surface.

SURFACE SIZED

Paper that has been treated with starch or other sizing material at the size press of the paper machine. This term is used interchangeably with the term ‘tub-sized’ although ‘tub-size’ more properly refers to surface sizing applied as a separate operation where the paper is immersed in a tub of sizing (starch or glue), after which it passes between squeeze rollers and is air dried.

SURFACE TENSION

The property, due to molecular forces, by which all liquids through contraction of the surface, tend to bring the contained volume into a form having the least area. If an ink is to be compatible with a substrate, the surface tension of the ink must approximate that of the substrate. Refer LM & IM.

SURFACE TREATING - See PRIMER, SIZING and CORONA DISCHARGE

SURFACTANTS

A coined word used in industry to include all surface active agents.

SYMBOL LENGTH

The length of a symbol measured from the beginning of the quiet area adjacent to the start character to the end of the quiet area adjacent to the stop character.

SYNTHETIC RESIN

Resins prepared by chemical means.

SYNTHETIC RUBBER

Elastomer manufactured by a chemical process as distinguished from natural rubber obtained from trees.

SYNTHETICS

Those materials developed and manufactured through chemistry, which tend to replace natural products.