Use Cluster Profile
This report presents a profile of the printing industry and defines a use cluster. Prepared as background for the U.S. Environmental Protection Agency (EPA), Office of Pollution Prevention and Toxics' analysis of printing use cluster chemicals, this report presents an overview of the chemicals, technologies, and processes used in the printing industry. Based on published information, this report's preparation involved neither original research nor an industry survey.
A use cluster is defined as a set of competing chemicals, processes, or technologies. Traditionally, EPA assessed the potential hazards and exposure scenarios of specific chemicals, and, generally, left the evaluation of potential substitutes as a post-risk assessment consideration. The use cluster approach considers all substitutes within a given use, and leaves consideration of alternate uses as a potential follow up activity.
Extremely limited information was found on the volume of chemicals used in the printing industry; however, information was found on inks and ink raw materials. In 1991, the U.S. market for printing ink was 1.9 billion pounds. The printing ink market is expected to grow at an average annual rate of 2.2 percent through 1996 when the domestic market is expected to total almost 2.2 billion pounds. Of the raw materials consumed in U.S. ink manufacture in 1991, excluding water, hydrocarbon and oxygenated solvents accounted for 35 percent, resins for 26 percent, oils (minerals oils as well as natural and synthetic drying oils) for 19 percent, pigments for 17 percent, and a wide range of additives for the remaining three percent. Similar information was not available for cleaning solvents or other chemicals used in the industry.
The printing industry is comprised of firms engaged in printing as well as firms which perform services for the printing trade, such as platemaking and bookbinding. The industry also includes firms engaged in publishing newspapers, books, and periodicals, regardless of whether or not they do their own printing. Firms functioning outside of what is traditionally defined as the printing and publishing industry also perform printing and related activities. For example, firms in many industries do printing in order to produce materials for internal use (i.e., in-plant printers). Other examples include: firms doing textile printing; manufacturers of products, especially packaging, that contain incidental printing; and manufacturers of printed circuit boards.
There are several estimates of the number of firms in the printing and publishing industry. Based on Census data, in 1987 there were about 58,000 firms operating a total of almost 62,000 establishments. The number of firms had increased to about 60,000 in 1993. However, the Census estimate does not include firms that do printing or related operations but whose primary activity is not printing or publishing. A.F. Lewis Co., Inc., a leading source of statistics for the industry, estimates that in the late 1980s there were almost 70,000 establishments in the U.S. performing some combination of prepress, press, or postpress operations. Almost 60,000 of these establishments were believed to have presses. It is believed, however, that these data excluded most of the screen printers. Their inclusion leads to an estimate of about 100,000 printing establishments in the U.S.
While the industry accounts for a significant portion of the Nation's total volume of goods and services, it also represents the largest conglomeration of small businesses in the domestic manufacturing sector. Nearly 80 percent of the plants in the industry employ less than 20 people. Most firms in the industry serve local or regional markets, though some printers and many publishers reach national and international markets.
In 1987, the industry employed approximately 1.5 million people with an annual payroll exceeding $33 billion. While employment remained steady, payroll increased to $39 billion in 1993. The Bureau of the Census estimates that in 1987, the total value of shipments for the printing and publishing industry was over $136 billion and by 1991 was almost $157 billion. When taking inflation into consideration, however, the industry experienced a decline in value of shipments of more than 2.0 percent over that period. The total value of shipments for 1993 was expected to be over $176 billion, which in constant dollars represents a return to 1987 levels. These estimates, however, exclude perhaps $90 to $100 billion worth of printed goods produced by in-plant printers and quick printers and by packaging manufacturers. The industry's poor performance during 1987 through 1991 was due primarily to overall sluggish economic growth during the period, particularly the recession of 1990 to 1991. Based on constant dollar sales, the printing industry is expected to grow by 3.8 to 5.3 percent annually between 1990 and 2000. Strong growth in the industry will result from a recovering U.S. economy as well as demographic trends favorable to the industry such as a substantial growth in the number of households and school-age children.
The printing industry is a very diversified and sophisticated industry owing to the multiplicity of printing processes utilized. The five most common printing processes, lithography, letterpress, flexography, gravure, and screen printing, currently account for about 97 percent of the value of the output of the U.S. printing industry. Based on the estimated value of 1990 shipments by the U.S. commercial printing industry, lithography accounted for 47 percent of the market; gravure, 19 percent; flexography, 17 percent; letterpress, 11 percent; and screen printing, 3 percent. The importance of letterpress, until the 1940s the dominant printing process, is declining very rapidly and is being replaced by lithography and flexography.
Printing Process Background
Some of the printing processes have several major subprocesses based primarily on the types of substrate or products printed. Lithography is divided into three subprocesses: sheetfed offset, heatset web offset, and non-heatset web offset. Gravure includes publication gravure, packaging gravure, and product gravure. Flexography consists of publication flexography and packaging flexography.
In addition to the five major printing processes already mentioned, there are various plateless printing processes. All comparatively new technologies, these include: electronic printing processes such as xerography and laser printing; ink jet printing; magnetography; thermal printing; ion deposition printing; direct charge deposition printing; and the Mead Cycolor Photocapsule process. Plateless printing processes are gradually becoming an important force in the industry because of their relative ease of use and the growing application of computer controlled printing operations. Although plateless processes accounted for only about three percent of total U.S. printing industry output in 1991, they are forecast to have a 21 percent market share by 2025.
The five major printing processes are distinguished by the method of image transfer and by the general type of image carrier employed. Depending upon the process, the printed image is transferred to the substrate either directly or indirectly. In direct printing the image is transferred directly from the image carrier to the substrate. The direct printing processes are gravure, flexography, letterpress, and screen printing. In indirect, or offset, printing, the image is first transferred from the image carrier to the blanket cylinder and then to the substrate. Lithography, currently the dominant printing technology, is an offset process.
Image carriers can generally be classified as one of four types: relief, planographic, intaglio, or screen. In relief printing, the image or printing area is raised above the nonimage areas. Of the five major printing processes, those relying on relief printing are letterpress and flexography. In planographic printing, the image and nonimage areas are on the same plane. The image and nonimage areas are defined by differing physicochemical properties. Lithography is a planographic process. In the intaglio process, the nonprinting area is at a common surface level with the substrate while the printing area, consisting of minute etched or engraved wells of differing depth and/or size, is recessed. Gravure is an intaglio process. In the screen process (also known as porous printing), the image is transferred to the substrate by brushing ink through a porous mesh
Printing Process Description
Each printing process can be divided into three major steps: prepress, press, and postpress. Prepress operations encompass that series of steps during which the idea for a printed image is converted into an image carrier such as a plate, cylinder, or screen. Prepress operations include composition and typesetting, graphic arts photography, image assembly, and image carrier preparation. Press refers to actual printing operations. Postpress primarily involves the assembly of printed materials and consists of binding and finishing operations.
Within each process, a variety of chemicals are used, depending on the types of operation involved. Prepress operations typically involve photoprocessing chemicals and solutions. Inks and cleaning solvents are the major types of chemicals used during press operations. Depending on the finishing work required, postpress operations can use large amounts of adhesives. This is especially true where the production of books and directories is involved. Of all the chemicals used in a typical printing plant, inks and organic cleaning solvents are the categories used in the largest quantities. Many of the chemicals used in the printing industry are potential hazards to human health and the environment.
The printing industry has been experiencing a period of great change, much of it fueled by the already widespread and still rapidly growing application of computers to the printing industry. In addition to the rapid growth of plateless technologies discussed above, major industry trends include:
- Increased automation.
- Continued rapid development in computer-based front-end platforms (e.g., desktop publishing).
- Advances in telecommunications and the introduction of digital data exchange standards.
- Development of new image carrier and image carrier preparation technologies
including direct-to-plate and direct-to-press processes and waterless
lithographic plates that do not require a dampening system.