Glossary

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DARK REACTION

Ultra Violet (UV) inks usually turn solid at the bottom of the can when the shelf of the material has expired. It is called this because it occurs in the absence of light, oxygen, and normal ink bodying agents. Refer IM.

DEBOSSED

An indent or cut in design or lettering of a surface.

DECKLE

The straps (deckle ruler) on the wet end of a paper machine which prevents the fibres from overflowing the sides and which determines the width of the web of paper which can be run on any given machine.

DECORATIVE SHEET

A laminated plastic sheet used for decorative purposes in which the colour and/or surface pattern is an integral part of the sheet.

DEFOAMER

A substance or mixture of substance which when added to foaming solutions causes small bubbles to collect into large bubbles which then rise to the surface and break (burst).

DELAMINATION

The separation of a material into layers in a direction approximately parallel to the surface. The partial or complete separation of the layers of a laminate. Refer NS.

DENSITOMETER

Instrument that measures reflected or transmitted light. A reflection densitometer is used as a control instrument to check uniformity and consistency of colour print. Refer NS for test procedure.

DEPTH OF FIELD

The range between the maximum and minimum distance from which a symbol can be read.

DESTATICISATION

Treating plastic materials to minimise their accumulation of static electricity.

DESTRUCTIBLE LABEL - See TAMPER-PROOF LABEL

DETACKIFICATION

The destroying of the tack or stickiness of a pressure sensitive adhesive.

DIAMOND SCREENING - See STOCHASTIC

DIE

Any of various tools or devices used for imparting or cutting a desired shape, form or finish to or from any material. A device in converting machinery used for cutting only the face material of a pressure sensitive laminate or for punching out shapes from the entire laminate or any other material.

DIE ADAPTOR

A device used to modify a die station of one type of press so that it will accommodate dies originally designed to be used on different presses.

DIE BLADES

Sharpened, thin steel blades used in flat or rotary dies. Also refers to blades on machine engraved or EDM (Electronic Discharge Machining) manufactured rotary dies.

DIE CUT

To cut labels with a die. The line of severance between a pressure sensitive label and its matrix or adjoining labels made by the cutting edge of a die. A term used to describe a label formed by die-cutting.

DIE CUT LABEL

Pressure sensitive labels mounted on a release liner from which the matrix has been die cut and removed. Refer NS & O.

DIE CUTTING

The process of using dies or sharp steel rules to cut any shape for labels. Refer NS & O.

DIE HOLD-DOWN ASSEMBLY

A steel block incorporating bearings which apply pressure to the bearer surface of a rotary die cutter through pressure screws. Can be calibrated.

DIE LIFE

Meterage expected from a new die or that expected following a re-sharpening of a die. Estimates of life of a die depend on machine, labelstock, adhesive and operator handling. Estimates of meterage vary significantly. Some companies charge re-sharpening or a new die whenever a repeat order is produced.

DIE LINES

A hand drawn or computer generated layout of the die cut shape or shapes on a clear or matt finish acetate or mylar. Used for layout.

DIE STAIN

Used to check die cutting accuracy. Usually done with diluted ink applied to the die cut surface of the backing or liner material. The ink seeps into any fractures of the silicone coated surface thereby exhibiting the problem areas. Refer NS.

DIELECTRIC

Dielectric values refer specifically to the insulating value of a material; a non-conductor of electric current.

DIELECTRIC PAPER

A dense, well formed, chemically pure paper used as an insulating material in electrical equipment to prevent the flow of electrical charges.

DIELECTRIC STRENGTH

The voltage which a material will withstand without allowing passage of the current through it.

DIFFERENTIAL RELEASE

A release liner with release coatings on both sides. One side has easy release while the opposite side is tighter such that the adhesive stays with the tighter side during winding and other subsequent converting.

DILUENT

A liquid used to thin ink. Refer IM.

DIMENSIONAL STABILITY

That property of a material which enables it to resist length, width, or thickness changes under varying conditions of heat, cold, moisture and other influences; ability to hold size, consistency of dimensions.

DIRECT THERMAL

Printing method utilising heat impinged upon a specially coated substrate so the heat turns the surface selectively black. A simple test to establish whether a substrate is direct thermal image or not, is to light a match and hold it near the substrate, close enough to discolour but not burn. A light bulb should produce the same effect.

DISCOLOURATION

Any change from the original colour, or an unintended inconsistence of colour.

DISCRETE CODE

A bar code or symbol where the spaces between characters (inter-character gap) are not part of the code.

DISHING - See TELESCOPING

DISPENSER

A device that feeds pressure sensitive labels, either manually or automatically, presenting them ready for application by hand or mechanical means. It can serve as a package for the labels as well (dispenser boxes).

DISPENSING EDGE

A relatively sharp edge around which the liner (backing material) is pulled in order to dispense a pressure sensitive label from that backing.

DISPERSION

A uniform distribution of solid particles in a vehicle.

DISTORTED

Intentionally compensating for shrinkage, stretch, etc. of a flexographic printing plate.

DISTORTION COPY

Copy which is intentionally distorted in preparation, in order to compensate for the effects of dimensional changes due to subsequent processing. Flexographic rubber plates require such allowances to compensate for shrinkage, etc.

DOCTOR BLADE

A thin flexible blade mounted parallel to and adjustable against the surface of an engraved anilox roller for the purpose of scraping off excess ink or coatings.

DOCTOR ROLL (ROLLER)

The fountain or metering roller in a flexographic press which doctors off the excess ink or coating from the engraved anilox roller.

DOT

The individual element of halftones. All the dots in a halftone plate have equal density and spacing, but to create the photographic reproduction effect (in colour or black on white) the dot count will vary in area.

DOT ETCHING

Chemically reducing halftone dots to control the amount of colour to be printed. Dot etching negatives increases colour; dot etching positives reduces colour.

DOT GAIN or SPREAD - Also See DOT GROWTH

A printing characteristic in which dots print larger on the paper than they are on the films, causing darker tones or colours.

DOT GROWTH

The increase in size of a dot from the film to the printed sheet. Dot gain consists of two (2) parts; physical dot gain and optical dot gain due to the physics of light absorption and reflection.

DOT MATRIX

A printing machine (Dot matrix printer) that is controlled by a computer or other such equipment, that produces an image by firing a series of pins or hammers (9 or 24 pin), against a ribbon and then onto paper usually backed by a hard rubber roller or similar hard surface.

DOUBLE COATED

A pressure sensitive product consisting of a carrier material with similar or dissimilar adhesives applied to the two (2) surfaces and wound with a silicone release paper (liner).

DOWNTIME

Any non-productive time caused by equipment malfunction, roll (paper) changes, plate or die problems, etc. Non-productive time. Maintenance time. Employee absence.

DRAW-DOWN - See MEYER ROD

A method of determining colour shade by drawing down a small amount of ink with a meyer rod.

DRIER

In ink making, it is any substance added to ink to hasten drying. Salts of certain metals that hasten the drying action of oils when added to coatings or sealers. The metallic salts most commonly used are those of lead, manganese and cobalt. Also part of the printing press through which the web travels in order to receive heat etc. to effectively dry (force) the ink or coating. Also spelled ‘dryer’. Does not include Ultra Violet Curing as this is a catalytic reaction. Refer IM.

DRIERS - As DRIER

DRIVING SIDE

That side of a flexographic press on which the main gear train(s) are located. Also gear side; opposite of operator side. Back of machine.

DROP-OUT

To knock out colour from behind another colour so that the first colour will not effect the appearance of the second colour.

DRY EDGE - See SELVEDGE

The edge of paper or film where there is no adhesive, This makes for easy removal of the release liner. Sometimes called Selvedge.

DRY LAP - See PATTERN COATED

DRYER - See DRIER

DRYERS - See DRIER

DRYING TUNNEL

A tunnel fitted with heaters (usually infra-red or hot air blowers) constructed to allow the printed web to pass through and speed up the drying process with water based, alcohol and oil based inks.

DRY SEAL ADHESIVE

One which is non-blocking except to itself. Two adherends may be pre-coated, dried, then bonded at any time using only nominal pressure.

DWELL

Refers to the length of time pressure is applied to a pressure sensitive label during production. The time that a hot-stamp, embossing head, or thermal die remains in contact with the surface of a pressure sensitive material. Also that time a pressure sensitive material remains on a surface before testing the adhesion or removability. Refer NS for test procedure.

DYES

Synthetic or natural organic chemicals that are soluble in most common solvents, characterised by good transparency, high tinctorial strength, and low specific gravity.

DYE TESTS - See DIE STAIN

DYNE LEVEL

Dyne is the measurement of surface tension or energy. The level is the actual reading of the critical surface tension. Low dyne levels indicate a low surface energy which can contribute to poor ink adhesion. Refer NS.