Glossary of Industry Terms
A means whereby the deterioration of a tape encountered in natural aging may be accelerated and reproduced in the laboratory.
Exposure in a chamber to ultraviolet light, heat, and water whereby the effect of outdoor exposure on a tape can be approximated.
A mechanical or chemically reactive bond between surfaces.
Adhesive Deposit or Residue
Adhesive that is pulled away from the tape upon removal and remains on the surface to which it has been applied.
The conveyance of adhesive from its normal position on the tape backing to a surface to which the tape was attached, either during unwind or removal.
The specific adhesion of a pressure-sensitive adhesive to a face material or an anchor coat.
A unit of length equal to 10-10meters.
Another name for the impression cylinder on a printing press.
A relatively thin flexible material to which the adhesive is applied. Theoretically, any material that is reasonably flat, thin, and flexible can be used as a tape backing.
An occlusive coating applied to the non-pressure sensitive side of a porous backing such as paper in order to provide a satisfactory surface that the pressure-sensitive adhesive side can contact when the tape is wound into a roll.
The designated fixed weight of 500 sheets, measured in pounds, in that paper’s basic sheet size. “Basic sheet size” is not the same for all types of paper.
In lithography, it is the rubber surfaced material which is fitted around the cylinder opposite the plate and transfers the inked image from the printing plate to the substrate.
The method used in the paper-making process to produce a bright white paper sheet. It produces dioxins.
In printing, this refers to printing the image beyond the edge that will be trimmed.
In ink making, this refers to the pigment that is washed or “bled” out of the vehicle system usually by the action of a solvent.
An undesired adhesion between layers of material placed in contact under pressure in storage.
Multi-layered paperboard used for fabricating boxes.
The thickness of paper when compared to its weight. A high bulk paper is thicker but less compact than a low-bulk paper of the same weight and size.
The ability of a tape to resist damage when a force is applied evenly and perpendicularly to the surface of a tape.
The thickness of a sheet of paper expressed in thousandths of an inch. Normally, paper caliper should not have more than a plus or minus 5% variance within a sheet. Generally, the relation between caliper and basis weight is the greater the caliper the greater the paper weight.
A webstock that holds pressure-sensitive adhesive especially used to refer to double-faced or double-coated tapes.
Any material which induces a chemical reaction.
Transparent protective coating.
The weight of a coating per unit area. In SI-unites expressed as grams per square meter (g/m2).
The ability of the adhesive to resist shear stress and splitting. Good cohesion is necessary for clean removal.
The tendency of a pressure sensitive adhesive to act as a heavy viscous liquid over long periods of time. Such phenomena as oozing and increase in adhesion with time are the result of this characteristic.
The ability of a tape to retain its original color, particularly when exposed to light.
The ability of an elastomeric adhesive, coating, or sealer acting as an insulator to withstand the effects of high voltage discharge. Indications of failure appear as surface cracks.
The slow movement of the adhesive or backing under shear stress.
Developing a three-dimensional molecular structure in an adhesive normally activated by heat or irradiation. An improvement in shear resistance, high temperature resistance, and oil or solvent resistance will normally result.
In U.V. systems, it refers to photopolymerization.
The tendency of paper by itself or in a laminate to bend or partly wrap around the axis of one of its dimensions.
A separation or splitting of the tape such as separation of the backing into two distinct layers, the separation between laminations of a tape consisting of more than one backing, the separation between filaments and backing of a filament reinforced tape, or separation of the adhesive from the backing.
Ability of materials to break down, by bacterial (biodegradable) or ultraviolet (photodegradable) action.
Shape in which material can be cut (Circle, Octagon, Oval, etc.).
The measure of the maximum voltage stress that a single layer of tape can withstand before dielectric failure occurs, the test being carried out under prescribed conditions.
That property of a material that relates to the constancy of its dimensions, particularly in relation to external influences such as moisture or temperature.
An adhesive application to both sides of a backing.
A method for estimating the skin or eye irritation due to contact with a chemical substance. Draize is expressed on a scale of 0 to 8.
The peeling back or lifting of the outer edge of an applied tape in a curved manner.
The tendency for the edge of an adhesive label to lift from a surface to which it has been adhered.
The extensive property of adhesive films or adhesive interfaces to contract and expand in such a manner as to overcome the differential contraction and expansion rates that the bonded adherends may exhibit.
A material which can be stretched at room temperature to at least twice its size and upon release of the stress, will return to approximately its original lenght. Elastomers are usually thermosets (requiring vulcanization) but may also be thermoplastic.
Electrolytic Corrosion Factor
A measure of the tape’s corrosive effect on an electrical conductor, particularly copper. This is particularly important in the selection of tapes for electrical insulation.
The entire range of radiant energy. Ultraviolet lies to the left of the visible region.
The distance a tape will stretch in the machine or cross direction before breaking under controlled conditions, expressed as a percentage of original length. Elongation is not necessarily an indication of conformability.
A condition which results from the excessive pick up of fountain solution into the ink resulting in the loss of ink film integrity and therebythe loss of print quality, i.e., too much “water” in the ink.
Any paper, film, fabric, laminate, or foil material suitable for converting into pressure sensitive material stock. In the finished construction this web is bonded to the adhesive layer and becomes the functional part of the tape construction.
When a tape pulls completely from the surface to which it is applied and drops off.
A weakness resulting from the stress created by repeated flexing or impact force upon the adhesive-adherend interface.
Thin, longitudinal yarns or threads of glass, polyester, nylon, or other high strength materials.
A condition sometimes occurring during removal of masking tape in which flakes or particles of paint flake away from under the tape backing.
The ability of a tape to withstand exposure to flame. Fireproof materials will not burn even when exposed to flame. Flame-resistant (fire-retardant, self-extinguishing) materials will burn when exposed to flame, but will not sustain burn after the flame is removed.
Most often, this printing process is simply referred to as “flexo.” it is letterpress printing that uses liquid inks rather than paste inks to achieve results.
Ink made with a pigment that absorbs light energy and re-emits it as a color.
Distortion of a roll of tape such that the layers no longer form a circle.
The distance from the lamp reflector to the focal point.
A U.V. lamp reflects and focuses the radiant energy into a point. When printing, the focal point should be at the substrate surface.
The roller(s) that comes in contact with the printing plate. In lithography this term also includes the roller(s) from the dampening system.
The ink or coating reservoir.
A molecule that is formed when a photoinitiator absorbs U.V. light.
Refers to the type of radical available for bonding. Mono- means one; di- refers to two; and, multi- refers to three or more.
Openings between layers of tape within the finished roll.
Grams per square meter.
A light reflection characteristic of tape backings, usually by such terms as glossy, low gloss, matte, etc.
This process is a form of intaglio printing that utilizes a cylinder into which the image is engraved. This engraved image area picks up liquid ink and transfers it directly onto the substrate.
An adhesive film intended to be reactivated by the application of physical or chemical changes caused by exposure to high temperatures.
Specks or dots in the printed copy that most commonly appear as voids that are caused by contamination such as dirt or dust.
A term referring to the process of unwinding or dispensing of tapes at a relatively high rate of speed, usually over 15 meters / minute.
The ability of a tape to resist static forces applied in the same plane as the backing. Usually expressed in a time required for a given weight and length of tape to shear free from a vertical panel.
A pressure sensitive adhesive, applied to the backing in hot liquid form, which then cools to form a conventional pressure sensitive adhesive.
The characteristics of color that causes people to describe it as yellow, blue, red, etc.
The moisture content of the air. Actual humidity is the number of grams of moisture in the air at any given time. Relative humidity is the percent of moisture relative to the maximum that air at any given temperature can retain without precipitation.
A tendency of some materials to readily absorb moisture from the atmosphere.
High Density Polyethylene – HDPE
A polyethylene thermoplastic made from petroleum that has a density of greater or equal to 0.941 g/cc. SPI resin identification Recycling No. 2.
The ability of tape to resist sudden impacts, pulls, or shocks as may sometimes be encountered by packages during transit.
In printing, refers to the amount of pressure between two surfaces such as the plate to substrate in letterpress; or, in lithography, between the plate and blanket or the blanket and substrate.
A substance added to an ink or coating to extend shelf life.
A non-uniform appearance of the ink in printed areas.
The property of a substrate which causes it to accept ink.
The ability of tape to prevent the flow of electrical current across its surface, usually measure on the backing.
Exposure to ultraviolet light or another high energy ray.
Kraft Paper – KFT
A paper produced by a modified sulfate process using only wood pulp. It is a relatively coarse paper and is known especially for its strength.
Pressure sensitive insulation. Materials furnished in roll or sheet form with liner, which can be later printed, frequently die cut, and intended for use as labels.
A joint made by lapping on material over another to provide a mated area that can be joined with an adhesive.
A stain in a surface to which tape has been applied, which does not become noticeable until some time after the tape is removed, usually after the surface has been exposed to sunlight or heat.
A printing process that uses a raised, reversed image plate to transfer the ink directly onto the substrate at which time it becomes readable. Letterpress was originally conceived with a flat plate, however, most modern presses are rotary i.e., they use print cylinders.
Another term for “dry offset printing.” A raised image plate is mounted on an offset press and transfers the image to the blanket without the need for fountain solution.
A situation where a section of tape has pulled away from the surface to which it has been applied.
Linerboard is the grade of paperboard used for the outer “facings” of a corrugated box. Kraft linerboard is made from wood fiber derived by the kraft process and typically contains no more than 20 percent recycled material.
The rate of travel of the substrate usually expressed in feet per minute.
A printing process that uses a plane surface printing plate and the interaction of an inking system and dampening system to achieve the resolution of the image.
Low Density Polyethylene – LDPE
A polyethylene thermoplastic made from petroleum that has a density range of 0.910 – 0.940 g/cc. SPI resin identification Recycling No. 4.
Medium Density Polyethylene – MDPE
A polyethylene thermoplastic made from petroleum that has a density range of 0.926 – 0.940 g/cc.
Thin flexible sheets of metal, such as aluminum, copper, and lead, used as tape backings because of their inherent properties such as weather resistance, electrical conductivity, reflectivity, etc.
A unit of length equal to one millionth of a meter or approximately 1/25,000 of an inch. Symbols used µm and mc.
A unit of length equal to one thousandth of an inch. One mil equals 25.4 microns.
Paper that has been discarded by any means during the manufacturing process within the paper mill.
Low viscosity liquids used as “solvents” in the ink or coating. A small molecule that may become chemically bonded to other monomers to form a polymer.
Moisture Vapor Transmission Rate
A measure of the rate of water vapor transmission through a pressure sensitive product usually measured in grams / square meter / 24 hours.
Thousand square feet.
Thousand square inches.
A low-cost, low-quality, non-archival paper. It is usually made by a mechanical milling process, without the chemical process that is usually used to remove lignin from the pulp.
A roll of tape in which the layers are in correct alignment, but the tape is displaced sideways on the core.
1. In printing, this refers to a press which transfers the image onto another surface (the blanket) before it is transferred to the substrate. The process may be either wet (with a dampening system), as in wet lithography, or dry (with raised image plate), as in dry offset.
2. This term is many times used instead of “set-off” or “blocking” to refer to the condition that results in the transfer of wet ink from the face of one sheet in a stack (or substrate wound into a roll) onto the back of another.
Old Corrugated Cardboard – OCC
Unbleached, unwaxed kraft paper with ruffled inner liner. Includes kraft linerboard, container-board cartons of corrugated paper, brown paper grocery bags. A recyclable material used to manufacture cardboard boxes.
A “squeezing out” of the adhesive from under the backing. Occurrence when a tape is in a roll form causes the edges of the roll to become tacky.
The ability of a tape to prevent the transmission of light.
A term describing the surface of a dried coating film which failed to flow out to a perfectly smooth surface, thus resembling the texture of an orange peel.
Oriented Polypropylene – OPP
A flexible material derived from melting and orienting, stretching polypropylene polymer.
The release of volatile components under heat or vacuum.
An ink or coating that is printed on top of a previously printed area.
A term that refers to the width and spacing arrangement of strips of adhesive laid down parallel to machine direction and across the width of pressure sensitive stock during its production.
The force per unit width required to break the bond between a pressure sensitive adhesive tape and the surface to which it has been applied when the tape is peeled back at a controlled angle at a standard rate and condition.
The chemical substance that absorbs U.V. light and by the formation of free radicals initiates the polymerization of vehicle.
A solid ingredient put into ink that gives it color.
The softening of an adhesive when exposed to migrating plasticizers or oils.
Polyethylene – PE
Called polythene in the U.K. A thermoplastic made from ethene through polymerization. Mechanical properties of PE depend significantly on variables such as the extent and type of branching, the crystal structure, and the molecular weight.
Polyethylene Terephthalate – PET
A thermoplastic polymer resin made from polyester. Also called PETE, PETP, and PET-P. PET is referred to as simply polyester while PET is most often used to refer to packaging applications. SPI resin identification Recycling No. 1.
The chemical reaction that takes place when monomers and oligomers join together or crosslink.
Polypropylene – PP
A thermoplastic polymer with a level of crystallinity intermediate between that of low density polyethylene (LDPE) and high density polyethylene (HDPE). SPI resin identification Recycling No. 5.
Polystyrene – PS
A polymer made from the monomer styrene. Plastic with a smooth surface that cracks easily when bent. Used for packaging, styrofoam cups and food serving and storage, it takes up a large part of landfill space because of its bulk. SPI resin identification Recycling No. 6.
Polyvinyl Chloride – PVC
Can be made softer and more flexible by the addition of plasticizers. In this form, it is used in clothing and upholstery. SPI resin identification Recycling No. 6.
The time after exposure to U.V. light when the U.V. film continues to react until ultimate film hardness is achieved.
A term commonly used to designate a distinct category of adhesive tapes and adhesives which in dry form (solvent / water free) are aggressively and permanently tacky at room temperature and that firmly adhere to a variety of dissimilar surfaces upon mere contact without the need of more than finger or hand pressure. These products require no activation by water, solvent, or heat in order to exert a strong adhesive holding force toward such materials as paper, plastic, glass, wood, cement, and metal. They have sufficient cohesive holding power and elastic nature so that, despite their aggressive tackiness, they can be handled with the fingers and removed from smooth surfaces without leaving a residue.
Pricing per 1,000 units.
In a subtractive light system (absorbed and reflected light) such as printing inks they are: yellow, magenta, and cyan. In an additive system (transmitted light), they are red, green, and blue.
Application of a thin layer of adhesive-like material to a backing that serves as a bonding agent between the backing and the final adhesive coat.
The unit of dose equal to an energy absorption of 100 ergs per gram.
A form of wave energy. Ultraviolet light is a form of radiant energy.
The measure of the force required to separate a unit width of pressure sensitive tape from a release coated surface at a controlled angle and speed.
It covers the adhesive side of the tape. It is removed prior to application. Most frequently found on double-sided tapes and label stocks.
The operation of winding the webstock from the reel onto a core to produce rolls of the desired width, diameter, and tension.
1. The physical “body” of the ink. Ink characteristics such as long or short, heavy, or soft are descriptions of rheology
2. Rheology is the study of the deformation and flow of matter under the influence of an applied stress.
A smooth paper made wholly or largely of hemp fiber for tensile strength.
Silicone one side. Coating is on only one side of the material.
Silicone two side. Coating is on both sides of the material.
Adding materials (saturant) to the backing for improvement of physical properties and resistance to various deleterious environments.
The ability of a dried ink film or substrate surface to withstand wear by friction.
An adhesive joint that is accomplished by coating both adhered surfaces, and bringing them under pressure; an elastomeric adhesive (cohesive) used on envelope flaps, box closures, etc, whereby the adhesive film will bond to itself.
Shear Strength After Solvent Immersion
The force required to separate a bond by shear force after immersion in a typical varnish solvent under designated conditions.
A tape to which a pressure sensitive adhesive is applied to only one side of the backing.
When the tape tears or breaks into small pieces, either on unwind or removal from a surface.
Surface protection film.
Material added to an ink to absorb free radicals and prevent polymerization in the can.
The force required to remove a unit width of pressure sensitive tape from a standard panel after it has been in contact with a release liner for a given period of time. This must be compared with the adhesion of the same tape that has not been in contact with the release liner to determine the degree of loss of adhesion.
The product upon which a coating or ink is printed.
The measure of surface tension in dynes. The lower the surface energy of a substrate, the more difficult it becomes for an adhesive or coating to wet out that surface.
Any method of treating a polyolefin so as to alter the surface and render it receptive to inks, paints, lacquers, and adhesives such as chemical, flame, and electronic oxidation.
A measure of the force required to split an ink film.
The force required to propagate a tear in a tape in a given direction after the tear has been initiated.
A sideways sliding of the tape layers, one over another, such that the roll looks like a funnel or a telescope, usually occurring over a period of time.
The force required to break a unit width of tape by controlled pulling on opposite ends of the piece.
Plastics which can be reformed repeatedly by applications of heat and / or pressure.
Plastics which once molded cannot be reformed using heat or pressure or used as adhesives. Polymer materials that cure, through the addition of energy, to a stronger form.
The perpendicular distance from one surface of either a tape, backing, or adhesive to the other, usually expressed in mils, thousandths of an inch, or millimeters. This is usually measured under controlled slight pressure with a special gauge.
A pressure sensitive adhesive unsupported applied to a two-side release coated liner.
Part of the electromagnetic spectrum. The 200 to 400-nm region of the U.V. spectrum is the portion used to dry U.V. curing printing inks.
Unwind or Unwind Adhesion
The force required to remove tape from a roll under prescribed conditions.
A measure of the resistance of a fluid to flow.
Water Penetration Rate (WPR)
The weight of water transmitted through a controlled area of tape under a specified time and conditions.
Water Vapor Transmission
The weight of water vapor allowed through a controlled area of tape within a specified time period and under controlled conditions.
The manner in which a coating flows out and levels over a substrate or ink.