P…

 

PACKAGING  A coordinated system for the preparation of goods for shipment, distribution and storage.

 

PADDING  Binding sheets of paper-blank, ruled, etc., together by applying flexible glue or adhesive to one edge of the stack.

 

PASS  One trip for the material through a production piece of equipment. Certain constructions require additional passes to complete the production.

 

PATTERN ADHESIVE  See pattern coated.

 

PATTERN COATED  Refers to the width and spacing arrangement of strips of adhesive laid down parallel to machine direction and across the width of pressure sensitive label stock during its manufacture. Also refers to adhesive coating applied in a pattern which is not related to web direction.

 

PATTERN VARNISH  Spot varnish applied to the printed surface in a desired pattern.

 

PCS  Print Contrast Signal. A measurement of contrast between the bars and spaces of a symbol. A minimum PCS value is needed for a symbol to be scannable. PCS values can be calculated and displayed automatically on suitable instruments.

 

PEARLESCENT PIGMENTS  A class of pigments consisting of particles that are essentially transparent crystals of a high refractive index. The optical effect is one of partial reflection from the two sides of each flake. When reflections from parallel plates reinforce each other, the result is a silvery luster. Effects possible range from brilliant highlighting to moderate enhancement of the normal surface gloss.

 

PEEL ADHESION  Peel adhesion is the force required to remove a pressure sensitive label from a standard test panel at a specified angle and speed after the label had been applied to the test panel under specified conditions for a specific time period.

 

PEELBACK  A method of separating a bond of two flexible materials or a flexible and a rigid material that have been bonded with an adhesive. The flexible material is pulled from the mating surface at a 90 or 180 degree angle to the plane in which it is adhered. The stress is concentrated only along the adhesive line of immediate separation.

 

PEELER PLATE A sharp edged, flat piece of metal around which the backing or carrier material is threaded, the prime function being a mechanical device which causes a pressure sensitive label to be dispensed from the backing material.

 

PENETRATION  Change of appearance of the face material due to movement of one or more components from the adhesive or the labeled surface.  Bleed through, migration.

 

PERFORATED Refers to a series of small incisions made in laid-on labels and/or their release liner to facilitate tearing along a predetermined line, or for fan folding.

 

PERMANENCY  A measure of an adhesive's ultimate holding power or bond strength. A permanent adhesive will develop a bond that makes label removal difficult or impossible without distorting the face stock.

 

PERMANENT ADHESIVE  An adhesive characterized by having relatively high ultimate adhesion to a wide variety of surfaces.

 

PERMEABILITY  The property of a material that allows a resists a substance to pass or flow through it; the rate of such passage.

 

PHOSPHORESCENT FACE  A face material coated with a phosphorescent ink, that emits light in a visible spectrum.

 

PHOTO INITIATOR  In ultraviolet-curing systems, the chemical which, when exposed to UV light, breaks certain chemical bonds in the system to start the chain reactions which cause polymer formation. This chemical is commonly referred to as a catalyst.

 

PHOTOPOLYMER  Plate material that is photosensitive and upon exposure, its compounds polymerize to form a tough, abrasion resistant surface which becomes the inking media.

 

PIECEWORK  Describes a payroll system generally used in production environments where employees are paid according to the actual number of pieces produced in a given time period.

 

PIGGYBACK  Pressure sensitive constructions that have two release coated liners, two layers of adhesive and a face material which allows a label to be applied, complete with backing, for future or further application.

 

PIGMENT  Finely ground, solid particles used to give color or opacity to printing inks and coatings, and usually insoluble in such a mixture.

 

PIN FEED See feed slots.

 

PIN REGISTER  The use of accurately positioned holes and special pins or pin bars on copy, film, plates and presses to insure proper register of colors.

 

PINCH ROLL  See nip roll or pull roll

 

PINHOLE  A very small hole which may permit the passage of light, moisture or electrical current.

 

PINHOLING  Refers to the failure of a printed ink to form a complete film. This condition will become visible by the appearance of small holes in the solid print area.

 

PIPING  Also known as tunneling, a condition occurring in an incompletely bonded laminate characterized by release of longitudinal portions of the substrate and delamination of theses portions to form these pipelike structures. The material fails to adhere to release paper or film tightly enough and a line of air forms between them. Usually starts at one edge and works across web.

 

PITCH DIAMETER  The measurement of a gear or cylinder, determined by dividing the circumference by Pi (3.1416).

 

PLASTICIZER  A substance added to materials to impart softness, flexibility, workability, elongation and dispensability.

 

PLASTICIZER MIGRATION  The migration of liquid plasticizers from some plastics into an adhesive and/or face material. Often causes excessive softening or degradation of adhesives.

 

PLASTICIZER RESISTANCE  Plasticizers can migrate into adhesives and/or inks and cause a breakdown, resulting in loss of adhesion to the substrate. If the adhesive or ink is formulated to resist the plasticizer, the breakdown may not occur.

 

PLATE The image carrier in letterpress and flexographic printing.

 

PLATE CYLINDER  There are two types of plate cylinders; the integral, with the shaft a permanent part of the body and the demountable, in which the shaft is removable to receive a multiplicity of bodies of varying diameters, and in some cases face widths. These plate rolls are undercut in their diameter so as to accommodate various thicknesses of mounting tape and plate materials.

 

PLATE ROLL  See plate cylinder.

 

PLATEN PRESS  Printing press in which a flat surface bearing the paper is pressed against a flat surface bearing the inked type.

 

PLIABILITY  See flexibility.

 

PLY  Each layer in a multi-layered structure.

 

POINT  Printer's unit of measurement to designate type size. There are 12 Points to a pica; approximately 72 points to an inch.  Also a term used for an expression of thickness of a sheet of material in one-thousands of an inch increments, i.e. 7 point = .007" thick.

 

POISE  The unit of viscosity, expressed as one dyne per second per square centimeter.

 

POLAR See non-polar

 

POLAR SOLVENT  Solvents with oxygen in their molecule, i.e. alcohols, water, esters, etc.

 

POLARITY  Refers to the relative surface charge of the material, resulting from the molecular structure of the adherend surface.

 

POLYCARBONATE  A high clarity film having the versatility of acetate with the durability of polyester.

 

POLYESTER  A strong film having good resistance to moisture, solvents, oils, etc. Usually transparent, although available with opaque and metallized finish. A clear complex ester formed by polymerization or condensation. Excellent strength, clarity and dimensionally stable.

 

POLYESTER LINER  A polyester film that is silicone release coated. It provides an excellent die cutting surface and is also used on overlaminating films to provide a smooth, glass-like surface of adhesive.

 

POLYESTER METALIZED FILM  A clear polyester film, vacuum metallized on one side to provide a metallic look.

 

POLYESTER OVERLAM  A clear, glossy polyester film coated with clear acrylic adhesive. Can also be supplied with a matte surface.

 

POLYETHYLENE  A tough, stretchy plastic film having very good low temperature characteristics.  Also used a great deal for producing semi-rigid recyclable bottles.

 

POLYMER  A compound formed by the reaction of simple molecules called monomers, having functional groups that permit their combination to proceed to high molecular weights under suitable conditions. A long-chain molecular structure.

 

POLYMERIZATION  A chemical reaction initiated by a catalyst, heat or light, in which monomers and/or oligomers combine to form a polymer.

 

POLYPROPYLENE  Similar to polyethylene but stronger and having a higher temperature resistance. Various thermoplastic plastics are polymers of propylene; excellent clarity. Also used in various thicknesses in the printing of labels as well as backing or liner materials.

 

POLYSTYRENE  A thermoplastic produced by the polymerization of styrene. The electrical insulating properties are outstandingly good and the material is relatively unaffected by moisture.

 

POLYVINYL  Refers to a group of resins formed by polymerizing various vinyl monomers.

 

POLYVINYLIDENE CHLORIDE  A usually very thin transparent film with excellent resistance to acids, water and organic solvents. SARAN.

 

POOR TRAPPING  Condition in wet printing that results when less ink transfers to previously printed ink than to unprinted paper. Also called under-trapping.

 

POP  Point of Purchase.  The location at which a product is sold, the store or retail counter.

 

POP DISPLAY  The displays or merchandising units used at the point of purchase.

 

POROSITY The property of paper that governs the degree of permeability. i.e. the passage of a substance through it.

 

POST CURE  The continuation of a polymerization (curing) process within a UV ink or coating, after exposure to  UV radiation has been terminated.

 

POT LIFE  The time period during which an adhesive or coating remains effective and workable.

 

PP Polypropylene.

 

PRE-SEPARATED ART  Artwork in which the basic layout, register marks and major color is prepared on illustration board and each additional color plate is drawn on a separate sheet or film overlay.

 

PRESS, IN-LINE  Press with the printing units in-line.

 

PRESS PROOFS  Printed sections of substrate material made on a press to allow for approval or final corrections before the production printing run is made.

 

PRESS SLIP COATING  An overall emulsion type coating applied in-line on a press to eliminate spray powder, usually having a good degree of slip additive.

 

PRESS, STACK  Flexographic press with printing units in horizontal stacks.

 

PRESS VARNISH  A clear varnish applied in-line on a press. It can be overall or printed in pattern from a plate to allow for dry laps and other uncoated areas.

 

PRESS, WEB  Press which prints substrates supplied on rolls.

 

PRESSURE BELT  Applies pressure by continuous hold-down of a label following application on automatic label application equipment.

 

PRESSURE BRIDGE  The steel support, mechanically secured over the die stations, through which the pressure screws are threaded.

 

PRESSURE ROLL  Holds product to be labeled in place for more accurate placement of label.

 

PRESSURE SCREWS  Steel shafts threaded through the pressure bridge which are used to apply pressure (in rotary die cutting station) to facilitate die cutting.

 

PRESSURE SENSITIVE LABEL STOCK  The combination of face material, pressure-sensitive adhesive and release liner from which pressure sensitive labels are manufactured.

 

PRESSURE SENSITIVE LAMINATE  See pressure sensitive stock.

 

PRESSURE SENSITIVE TAPE  A combination of a pressure sensitive adhesive with a carrier. Tapes are either self-wound or utilize release liners or films.

 

PRICE MARK  Special pressure sensitive stock for use in pricing guns.

 

PRIMARY LABEL  Label that acts as the main identification of a product. Often designed to attract attention and contains information to appeal to a buyer and is usually applied at the time of its manufacture.

 

PRIME COAT  Base coat applied first to enhance subsequent printing.

 

PRIME LABEL  A label used to identify and display a product, i.e. a major product panel.

 

PRIMER  Surface coating applied between face stock and adhesive to improve bond performance and/or prevent bleed.  See barrier coat.

 

PRINTABILITY  The ability of a material to accept and hold a printed legend, and especially to resist offset of the printing when rewound into a roll after printing.  Also a collective term used to describe the properties required of all components in the printing process.

 

PROCESS PRINTING  Printing from a series of two or more halftone plates to produce intermediate colors and shades. In 4-color process, the colors are yellow, magenta, cyan, and black.

 

PRODUCTION CONTROL  A system to ensure the efficient use of materials, manpower, facilities and transportation in order to assure the availability of a specific product, in a predetermined quantity, within a specified time period.

 

PRODUCTION RUN  The final printing requested by the customer from the original artwork.

 

PROGRESSIVE PROOFS  Proofs made from the separate images in color process work showing the sequence of printing and the result after each additional color has been applied. Also called progs.

 

PROOFING PRESS  Press that produces printed progressive proofs.

 

PROTECTIVE COATING  A coating that protects the printing and the surface of a pressure sensitive label from either abrasion, sunlight, chemicals (their fumes and dilute solutions) and moisture or a combination of these.

 

PSI  Pounds per Square Inch.

 

PULL ROLL See nip roll

 

PULL TAB  Area on a face stock that facilitates easy removal of the label, usually a cut area on a sheeted label. Also called a peel tab and tear tab.

 

PUNCHED OUT LABELS  Anvil cut or sheeted labels.

 

PVC  Vinyl; polyvinyl chloride.