Printing Knowledge

The in-line press is the third commonly used type of wide-web press. Its color stations are separate, complete units horizontally mounted one to the other, and may be driven by a common line-shaft. In-line presses can be manufactured with any number of colors. This type of press can be easily designed to handle varius web widths, from narrow to ext…

Folding cartons have been printed by flexo for many years, but it has only been in the past 10 years that the industry has started using state-of-the-art central impression presses for this application. Pizza cartons illustrate the type of work that was originally relegated to the flexo process. The ability to print multi-colors in close register o…

Narrow-web flexo has most recently been defined as any web width less than 20" (508mm). While this is an arbitrary designation, it will serve as a definition for this chapter. The vast majority of narrow-web presses, however, are 16" (406mm) or less, and most are 10" (254mm) or smaller, However, changing market conditions and the need for greater p…

The origin of narrow-web flexography is usually placed in the period immediately after WW ll. At that time, Mark andrews Sr. (1904~1980), the founder of Mark Andy, Inc., made his first presses for printing on the then new product, "scotch Tape." Others may have made similar equipment prior to this but, unquestionably, Andrews was the first to begin…

Many types materials can be printed. Plastic, glass and fabric are just some. However, by far the most important printed material is paper. Paper is needed for letterheads, envelopes, invoices, checks, travel brochures, calendars, advertising pieces and catalogs. And, of course, paper is an essential ingredient in newspapers, books, and magazines. …

Making paper by hand is an excellent way to become familiar with the basic procedures of papermaking. Extensive equipment and materials are not required. Equipment includes a tub large pail, a mold, and a deckle. These three items are shown in Figure 5-1. The mold is a wooden frame covered with a metal screen. The deckle is another frame the same s…

Cellulose fiber. The principal raw material for producing paper is cellulose fibers, which are short, threadlike structures. Cellulose fiber is the basic building block of plant matter, and large amounts of it can be extracted from wood. There are four main sources of cellulose fiber used in the manufacture of paper; softwood trees, hardwood trees,…

There are two fundamental steps in papermaking. First, the fibrous raw material, or cellulose, from pulpwood, nonwood fibers, or recycled papers is converted into pulp, a mass of fibers suitable for papermaking. Second, the pulp is interwoven and bonded into a structure known as paper. Pulping permits papermaking fibers to be separated from wood.Th…

Some of the most common printing papers are bond, book, cover, bristol, newsprint, duplicator, and mimeograph. User for each of these kinds of paper and information about their basic sizes and basis weights are included in, Figure 5-6. Basic size is the standard sheet size in inches. This size is used by the paper mill to compute the weight of each…

Some papers are very adaptable to several applications, while others others are very limited. The next section will briefly discuss the types of paper that are acceptable for different printing processes and applications. Paper for gravure.  Generally, gravure produced newsprint will contain mineral fillers and a calendered surface. Many mail orde…

Not only must paper be handled carefully during shipment but it must able be handled carefully in the plant. Paper must be brought to pressroom temperature before opening so that it does not curl due to the gain or loss of moisture. Paper should remain tightly wrapped until it is ready for the press, and it should be wrapped tightly after printing …

Ink is transferred from a plate or stencil to paper or some other material during the printing process. The ink forms the image on the printed product. Most printing inks consist of pigments, vehicles, and modifiers. Pigment is the ingredient that provides the color of the ink. Many pigment colors are produced from rocks and clays. Others can be tr…

Ink manufacturing (Figure 5-10) is complex and requires extensive chemical and printing process knowledge as well as specialized ink manufacturing equipment use. While there a number of manufacturing methods, most share these basic phases of production: formulating, premixing, milling, filtration, and testing. Formulating.  Since formulation of in…

Many times, a customer requests a specific color other than black, cyan, yellow, or magenta on the ink required, the printer either orders the specific color from the inkmaker or mixes it in the printing plant. Obtaining the ink from the inkmaker is preferred if the color is a shelf ink or if the amount required is large. Small amounts of a particu…

Each printing process requires the use of an ink developed specifically for that process. Letterpress, gravure, lithographic, and screen-process inks are specially formulated to match the requirements of the printing process. For example, letterpress inks are designed to distribute evenly over and adhere well to raised plate surfaces. Gravure inks …

The most aggravating problems in lithography are often interaction problems, which arise when there is more than one deficiency among the paper, ink, press, and press operation factors. Consequently, adjusting the press may solve the problem temporarily, only to have it recur later or to have it pop up as a "different" problem. Even if the ink is n…

The sequence of steps in binding hardcover books is shown in Figure 6-1. These steps remain the same whether books are bound by hand or by machine. FOLDING SIGNATURES AND ENDSHEETS. Large printed sheets are first folded to form signatures. A signature is a single sheet of paper folded to a certain number of pages. For example, one signature may yie…

Self Covers Self-covers are produced from the same material as the body of the book and generally carry part of the message of the piece. Newspaper and some news magazines have selfcovers. The method requires no special techniques to assemble or attach the cover to the body of the work. The process is generally restricted to the less expensive bind…

Finishing refers to several operations that may be performed on printed material after it has left the press. The most common finishing operations are cutting, folding, and gathering. other finishing techniques include scoring, perforating, drilling, embossing, and die cutting. CUTTING.  Cutting is done to make a large sheet of paper into several …

Sheets of paper may be bound together in several different ways. The most common methods include: saddle-wire, side-wire, sewn soft-over, sewn case-bound, adhesive, mechanical, and loose-leaf binding. SADDLE-WIRE BINDING. The saddle-wire method of binding, Figure 6-22, uses wire staples as the fastening device. These staples pass through the back o…