LAMINATING TERMS | PAPER TERMS

Laminating Terms

Acetate: Cellulose acetate or cellulose triacetate or cellulose acetate butyrate. Has the appearance, toughness, heat and solvent resistance found in polyesters.

Acrylic Resin: A glassy thermoplastic made by combining several acrylic acids used as coatings and adhesives.

Adhesion: The process of holding materials together by surface attachment.

Belled Edges: A raised edge(s) of a slit roll.

Blocking: A condition whereby the laminating film sticks to itself on the film roll and is hard to unwind during lamination. The condition occurs under storage or use.

Bond Strength: Refers to one of three conditions:  1) anchor strength of adhesive to the substrate in laminating film; 2) the anchor strength of the laminating film to the product that has been laminated; or 3) the strength of adhesive-to-adhesive bond when two layers of film are laminated together.

Coating: The process of applying an emulsion, varnish or lacquer over a printed surface to give it added protection.

Coated Paper: Paper having a surface coating which produces a smooth finish.  Surfaces vary from eggshell to glossy.

Contamination: Foreign substance on the film, i.e. bugs, wax, fiber, trim, drool.

Copolymer: Combination of two chemical compounds used in special adhesives.

Core Overhand: Core is larger that the roll opposite of recessed core.

Creases: A permanent line in film surface caused by folding.

Delamination: Refers to either of two conditions where: 1) the laminating film separates from the product; or 2)  the base film separates from the adhesive. The latter illustrates an inferior bond during the manufacturing of the film.

Edge Variation: Change in edge registration due to a small amount of film protruding beyond the edge of a roll.

Emboss: The process of impressing an image onto a product to achieve a raised surface on the product.

Encapsulation: A term which refers to the product being totally encased in the laminating film. Generally a border would exist around the product where the top and bottom film layers are bonded together.

Extrusion: Converting plastic pellets or granules into a continuous uniform melt and forcing this melt through a die that yields desired shape.

Extruded Film: Film that has had thermoplastic adhesive applied to under force through a flat die.

Film Gauge: Refers to total thickness of a particular film construction including its individual layers.  The gauge is measured with a micrometer.

Flexography: A process of rotary printing using flexible rubber plates and rapid drying inks. Most often used in label printing industry.

Flush Cut: Refers to the trimming of excess film from the edges of the laminated document. Flush cutting exposes the edges of the material and increases the likelihood of the material splitting.

Footballs: Microscopic bubbles in the film caused by entrapped air between substrate and adhesive. The laminated film appears streaky and cloudy.

Gauge: Synonym to thickness of caliper. Measured with a micrometer especially designed for films.

Gauge Band: A term used to describe waves or ridges in a roll of film. This is caused by very small irregularities in the film web thickness. As the film web is wound onto a roll, this irregularity becomes noticeable to the eye. The irregular thickness may be in the base film, the adhesive layer, or both.

Gels: A term used to describe speckles in the film caused by hard adhesive resins which did not fully melt during film manufacturing.

Heat Shoe Laminator: This type of machine applies laminating film to both sides of the document simultaneously. The laminating film adhesive is activated by passing over stationary heaters, called shoes. Economy grade polyester films are commonly used on heat shoe laminators.

Kraft: A strong paper made from wood pulp, derived from wood chips boiled in an alkaline solution containing sodium sulfate.

Lamination: A plastic film bonded by heat and pressure to a substrate for protection and appearance.

Letter Press: A process of printing from an inked raised surface impressed directly onto the paper surface.

Lithography: The process of printing from a plate on which the image to be printed is ink-repellent and the bland or non-image area is ink absorbent. Ink applied to the plate surface is repelled by the image area, and so can transfer the image to paper.

Master Roll: Term used to designate the manufactured roll from which the narrower, standard stock rolls are slit. Also called mother roll and mill roll.

Matte Film: A type of laminating film having a dull finish with low reflectivity and capable of receiving pencil marking.

Mill Roll: See Master Roll.

Mother Roll: See Master Roll.

MSI: Abbreviation for thousands (M) of square inches (SI).

Mylar: Trade name for polyester film manufactured by the E. & I. DuPont DeNemours Company.

Nipping: Squeezing together of hot laminating film and product to be laminated or another piece of laminating film.

Offset: A printing process, by which an inked impression from a plate is first made on a rubber-blanketed cylinder, then transferred to paper.

Offset Powder: A dry spray used on printing presses to prevent wet ink transfer from the top of one sheet to the bottom of the next sheet. Also known as press powder.

Olefin: A term referring to a specific group of synthetic polymers. Polyethylene and polypropylene are included in this group.

Overshoot, Initial: Refers to the temperature of heated rolls upon initial start-up after the controlling thermostat has shut down the power. The accumulation of heat within the heaters causes the temperature to briefly rise above the normal control value.

Polyester: Shiny, transparent, tough, Thermoplastic Polymer used as the substrate for laminating films.

Polypropylene: Soft, transparent, acid resistant, Thermoplastic Polymer used as a substrate for laminating films.

Polyvinyl Chloride: Also called PVC. Rigid variety used in Cerlox and flexible variety used in metal loose-leaf binders. PVC is also used to make credit cards in a platen press, etc.

Porosity: The property of a paper that allows the permeation of air, an important factor in adhesive penetration.

Pressure Sensitive Film: Pressure sensitive film is transparent and applied to a given material without the use of heat. Once the protective backing is removed, the film is then pressed on the material to be laminated.

pt: An abbreviation for Point, a printer’s unit of measurement regarding paper thickness.  There are approximately 72 points to an inch, and 10-pt paper equates to 10 mil laminating film.

PVC: See Polyvinyl Chloride.

Screen-Printing: The process of forcing ink through a fine mesh, transferring an image onto paper. The image is produced by controlling the holes or pores in the screen material. Also called silk screen.

Signature: The name given to a printed sheet which when folded becomes one unit of a book.

Silvering: A term used to describe air pockets trapped between the product and the adhesive on the film.

Squeeze-Out: Refers to heat-activated adhesive that has been forced out at the edges of the laminate. The effect can be minimized by employing the lowest practical laminating temperature.

Streaks: A term used to describe white lines in the film caused by entrapped air between the film substrate and adhesive layers of the film. This condition is caused during the extrusion of the adhesive on the film.

Substrate: A material to which an adhesive is coated. (i.e. polyester, paper, polypropylene, nylon, acetate)

Tenting: A term used to describe the laminated appearance of the space surrounding the photograph which is mounted on another object. Two factors control the size and appearance of tenting: 1) the thicker the photograph, the larger the tent; 2) the thicker the adhesive layer the less tenting there will be.

Textured Laminate: A pattern introduced onto the film laminate by the use of specifically engraved rollers. Linen weave and leather finish are typical.  Used especially by professionals in commercial photography.

Varnish: A thin, protective coating applied to a printed sheet for protection or appearance.

Viscosity: The measurement of how fluid a substance is.

Web: A term used to describe film unreeled from a film supply roll. May be a single layer or comprised of several components bonded or laminated together.

Web Press: A printing press which prints on rolls (or webs) of paper.

Paper Terms

Basis Weight: The weight of 500 sheets of paper cut to a standard specific size. A basic sheet size is common to each major paper grade. The basic sheet size of cut-sheet paper is 17 x 22". If the total weight of 500 sheets of 17 x 22" paper is 20 pounds, the paper is described as 20-pound paper.

Brightness: A standard measurement of the percentage of light reflected back from a sheet. A 90 brightness indicates the sheet reflects 90% of the light striking it.

C1S: Coated on a single side.

C2S: Coated on both sides.

Caliper: Thickness of a single sheet of paper, in thousandths of an inch, measured with a micrometer.

Chemical Pulp: A layer of clay or pigment, in combination with an adhesive, applied to paper.

Coated: A layer of clay or pigment, in combination with an adhesive, applied to paper.

Conductivity: The electrical properties of a sheet that influence toner transfer and image quality.

Cover Paper: Heavier papers generally used for book covers, folders, greeting cards, business cards and brochures.

Electrophotography: The printing or copying process of using an electric charge to create an image on a photoconductive surface. This surface is cleaned after each image.

Free Sheet: Paper containing 10% or less groundwood pulp.

Glossy: Coating a sheet to achieve a shiny or lustrous appearance.

Grades: A generic system of classifying papers by common characteristics or composition. Grades are further refined to reflect specific quantities or uses.

Grain: The dominant direction of the fibers in a sheet.

Groundwood Paper: Papers made from mechanical pulping processes, which leave many natural impurities in the paper.

Matte: A non-glossy coating on paper.

Moisture Content: An important property of copier and printer papers affecting paper curl and static build-up.

Newsprint: A grade of paper composed primarily of groundwood pulp.

Opacity: A measure of the property that prevents print from the other side from showing through the sheet.

Porosity: The amount of air that will pass through a sheet, important in vacuum-assisted feeders.

Sizing: A substance added to pulp before papermaking or to the surface of a finished sheet. Sizing serves several different functions, depending on the end use of the sheet: as a glue to hold fibers together, an enhancer of water resistant qualities, or a controller of the reaction of ink with the sheet.

Smoothness: A precise measurement of the surface of a sheet of paper, optimized for print equipment. Too smooth a sheet may cause runnability problems; too rough a sheet may affect image quality.

Web Paper: A roll of paper cut into sheets after it is printed.