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Glossary

  A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z  
A TOP
Angle of Attack - The angle formed by the face of the moving squeegee blade and the plane of the screen, under pressure. Due to the flexibility of the blade, this angle generally differs from the squeegee angle, which is measured without movement or pressure. 

Anilox Roll - Anilox rolls generally are steel with ceramic coating. Etched into the ceramic are cells that are used to transfer controlled volumes of ink to the flexographic printing plate. Between print jobs they must be cleaned of ink. Anilox rolls used in narrow web presses typically have face lengths up to around 30 inches. These rolls are often installed and maneuvered by hand, and can approach 100 pounds. Anilox rolls on wide web presses are longer (typically up to 100 inches, but can be much longer) and can weigh several hundred pounds. They are typically moved with cranes or robotically because of their weight and size. Anilox rolls on corrugated presses are also very large and are normally cleaned on-press. The design of corrugated presses allows for separation of print units.

Anilox Sleeves - Anilox sleeves are used as a lighter alternative to anilox rolls. They are also ceramic coated, but are hollow and slide over steel cylinders which remain on-press.  They are placed on-press by injecting air pressure into the cylinder. This provides a cushion of air so that the sleeve can slide onto the cylinder face from a shaft on a storage/transport cart. Once in place on the cylinder on the press, the air pressure is released, causing the sleeve to deflate resulting in a total, uniform grip to the cylinder surface.
B TOP
Blanket (Lithography) - A rubber-coated fabric mounted on a cylinder that receives the inked impression from the plate and transfers (or offsets) it to the paper.

Bundle - A stack of signatures strapped together for later use in other binding and finishing operations.
C TOP
Coated Screen - A printing screen with direct emulsion applied to the fabric preparatory to exposing.

Coater (Emulsion Applicator) - A tool with a rounded, sometimes slotted edge used for evenly spreading sensitized emulsion on the fabric of printing screens.

Collating - Where cut, trimmed, or folded printed pieces are assembled in proper sequence to prepare printed materials for further binding operations.

Conveyor - A set of power actuated or non-powered rollers configured to move materials through a production process line or between job stations. 
 
"C" Shaped Hand Posture  - Positioning fingers and thumb in the form of a "C" provides neutral postures for fingers and thumb eliminating pinch grip. This is the desired hand posture for using hand tools. C shaped hand posture illustration
Figure 1. "C" shaped hand posture illustration.
D TOP
    Doctor Blade - A thin, flexible, adjustable blade mounted parallel against the anilox roll for the purpose of scraping off excess ink.
F TOP
Fabric Stretcher - A mechanical device for tensioning screen printing fabrics over the screen frame, accurately and correctly.

Fanning - An operation in which sheets, or pages are separated so that individual pieces do not stick together.

Flexography -A method of direct-rotary printing, using resilient raised-image printing plates, affixed to variable-repeat plate cylinders, inked by a roll or doctor blade-wiped engraved metal or ceramic roll carrying fluid inks to virtually any substrate.

Flood Bar
- The device on a screen printing press comprised of a thin metal (or plastic) blade, which has the function of spreading a thin film of ink uniformly over the printing screen, in the opposite direction of and preceding the printing stroke.

Folder (Lithography) - Machine that creases and scores printed sheets of paper to particular specifications during binding and finishing. The process itself is called folding. 
I TOP
Image Area (Lithography) - The area that has been specially treated to receive ink and repel water.

Ink (Flexography) Fast drying fluid (water- or solventbased) or paste-type (UV cured) ink.
J TOP
Job RotationThe process of periodically moving employees between different jobs or tasks to minimize monotonous activities and overexertion of particular muscles or tendons. The jobs within the rotation should use differing muscle-tendon groups allowing for rest and recuperation. Tasks should be categorized based on parameters such as high/low repetition, high/low force exertion, maintaining awkward postures for prolonged periods, and the areas of the body affected. The jobs within the rotation should use differing muscle-tendon groups or alternate between extremes of parameters such as high or low force. This will provide the opportunity for "working" rest and recuperation.

In small shops where a few employees perform multiple tasks the opportunity to rotate may not exist, but in these shops the variety of tasks that are performed during the shift will provide a built in rotation scheme. Workers in these shops should look for chances to move between tasks where parameters such as force can be altered between high and low. In larger shops, where there is enough work for dedicated stations, a formalized rotation scheme should be developed which moves people between stations.

Jogger - A device comprised of a vibrating table, the action of which squares and neatly stacks a pile of sheets of paper.

Jogging - The process of aligning or moving even sheets of paper to a common edge to produce a neat stack.
L TOP
Lithography - A printing process in which the image carrier is chemically treated so that the non-image areas are receptive to water (i.e., dampening or fountain solution) and repel ink, while the image areas are receptive to ink and repel water.
N TOP
Neutral Postures - Postures where the body is aligned and balanced, while sitting or standing. The head is kept upright and is not turned to either side more than about 30 degrees or tilted forward or backward more than about 15 degrees. When the worker is standing, the torso is not bent more than 10 to 20 degrees from the vertical position and the natural curves of the spine are maintained. The pelvis and shoulders should face straight ahead to avoid twisting the torso. The shoulders are relaxed and knees slightly bent. The arms hang normally at the side, with elbows close to the body. The elbows are not bent more than about 90 degrees and the palms face in toward each other and the center line of the body. The wrists are in line with the forearms and are not bent sideways, forward (towards the palm), or backward (towards the back of the hand.) When the worker is seated, the buttocks and feet are firmly supported.
O TOP
Offset Printing - An indirect printing method in which the inked image on a press plate is first transferred to a rubber blanket that in turn transfers ("offsets") the inked impression to a press sheet. In offset lithography, the printing plate has been photochemically treated to produce image areas and non-image areas receptive to ink and water, respectively.
P TOP
Photopolymer Plate A flexible, relief printing plate made of either precast sheet or liquid light-sensitive polymers. Photopolymer plates require exposure to UV light during the platemaking process to cure the raised image. This is followed by washout of unusable portions and drying.

Plate (Flexography) Flexographic printing plates are relief-printing plates made of rubber or photopolymer. Rubber plates are engraved or molded. Photopolymer plates require exposure to UV light during the platemaking process. Plates are mounted on plate cylinders.

Plate (Lithography) - A thin metal, plastic, or paper sheet that serves as the image carrier.

Plate Cylinders - A steel cylinder to which flexographic printing plates are mounted, using a double-sided, sticky-back tape.


Plate Sleeves - A flexographic printing plate formed as a sleeve, in a continuous circle. The sleeve slides over a plate cylinder.

Pockets - The hoppers on a binder that are loaded with the signatures to be bound into a book or magazine.


Prepress The steps required to transform an original image into a format that is ready for reproduction by printing, including such activities as art and copy preparation, photography, image assembly, and platemaking.
R TOP
Rack Drying - The drying of screen printing sheets in racks, usually in ambient temperatures, but also placed in a room where temperatures are elevated.

Racking - The manual placing of screen printing sheets on racks for drying.

Ramp-Up Period The time allowance for employees to establish the amount of material they can safely handle using a pinch grip.

Reclaimed Screens - Printing screens conditioned for re-use by removal of excess ink and stencil, and reconditioning if necessary of the screen printing fabric to receive a new stencil.

Reclaiming - (1) The process of removing both ink and stencil from the screen fabric after a printing run in order to reuse the fabric for a later job; (2) the process of distilling used solvents to obtain a reusable, cleaner solvent for cleaning screens.

Roll - Substrate or printed product produced in a continuous strip and wound uniformly around a central shaft or hollow core.

Roll Core -
The hollow center of a roll.

Roll Jack - A mechanical device used to lift and/or move rolls around the work area.

Roll Shaft - A metal rod placed in the hollow core of a roll used to hold the roll in place while on a web press.
S TOP
Scoring - To compress or crease heavy substrate along the fiber line to facilitate folding or tearing.

Screen
- (1) Printing Screen: an assembly of stretched screen printing fabric on a frame with stencil attached, ready for printing; (2) Halftone Screen: a transparent glass sheet marked with cross-hatched design to be placed before the camera film when photographing continuous tone art to produce dot structure of the design in the negative. Another type is produced photographically on film with vignette dots. The latter is placed in contact with the negative film.

Screen Mesh - (1) A term generally indicating screen printing fabric; (2) that portion of the screen printing fabric which can be counted or measured to identify fineness or coarseness of the fabric.

Screen Printing - A printing process which involves passing ink through an open-weave screen fabric which is coated with a stencil.  The stencil blocks the non-image areas, allowing the open areas of the fabric to pass ink to reproduce the image.

Screen Washer - A unit in which printing screens can be washed out to remove ink residues after printing, or be reclaimed completely by removing the stencil, usually by high pressure spray.

Sheet Fed Press - An offset lithographic printing press that prints on individual cut sheets that are fed into the press one at a time.

Signature - One or more printed sheets folded to form a multiple page section of a book or pamphlet. Signatures are most commonly grouped as four, eight, sixteen, or thirty-two pages. Various combinations of multiple page signatures create the full complement of pages needed in the printed piece.

Solvent - A dissolving, thinning or reducing agent. An additive used to reduce viscosity of a screen printing ink, generally. Specifically, a solvent is a liquid that dissolves another substance such as resin.

Spinning Disc - A metal disc placed under a roll-off press to allow for easier positioning or repositioning of a roll.


Squeegee - A tool used to force ink through the openings of a screen printing stencil when in contact with a substrate, consisting of a rubber or plastic strip or blade held in the edge of a wooden or metallic handle.

Squeegee Angle - The angle formed by the near-vertical axis of the squeegees and the plane of the screen, measured when the squeegee is in position, but no force or movement has been applied.

Stacker - A device attached to the delivery conveyor of a web press that collects, compresses, and bundles printed product.

Stencil - The component of a printing screen which controls the design to be printed.

Stretch - (v) The tensioning of screen printing fabric preparatory to securing it to the printing frame, or by self-stretching frame; (n) the degree to which a material can accommodate deforming tension.

Stretch Frame - A screen printing frame so constructed that after the fabric is secured, additional stretch can be applied by threaded rods bolts, cams, corner adjustments, etc. Also called "retensionable frame".

Substrate - Any base material with a surface that can be printed or coated. This material may differ in shape and size. Examples include paper, plastics, pressure sensitive adhesive material (such as bumper stickers), textiles of all kinds, metal, glass, ceramic, leather, and wood.
W TOP
Web Press - A rotary press that prints on a continuous web, or ribbon, of substrate fed from a roll and threaded through the press.
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