Profile and pipe extrusion will continue to be high-growth markets for plastics in the United States during the next several years, predicts a study issued by Plastics Custom Research Services of Advance, N.C. Profiles were the fastest-growing U.S. plastics processing sector in the decade ended in 1999, and pipe was the fourth-fastest, according to the PCRS study. In terms of pounds of plastics consumed, profile extrusion grew an average of 9.4 percent per year for the 1989-99 period, while pipe extrusion grew 7.7 percent.
PCRS President Peter Mooney, the study's author, said construction has fueled growth in the profile and pipe sectors. Wider acceptance of vinyl siding, windows, fencing and other products boosted extrusion of those components. Plastic pipe benefited from building-code changes that allowed the products to penetrate a wider range of municipal and residential areas. Both also gained in recent years from the overall construction boom, and Mooney predicts the sectors will remain strong.
Structural foam molding ranked second-largest in growth, the study said. Although it was popular in the 1960s and 1970s, structural foam later had setbacks when many appliance and electronics housings switched to thin-wall injection molding because of better surface appearance.
Mooney said structural foam molders since have gone back to their strengths, making large, functional parts in which aesthetics aren't important, such as pallets and junction boxes. That change boosted growth in the last few years of the decade.
Blow molding, at 7.8 percent annual growth for the decade, was the third-highest growth sector. Mooney said blow molding's packaging applications are maturing and growing at about the level of gross domestic product, but there still is a lot of potential in industrial uses.
Injection molding represented 18.9 percent of U.S. plastics consumption in 1999, the largest single sector. Its annual tonnage growth during the decade, at 6.3 percent, was just above the overall industry average of 6 percent a year.
Mooney said injection molding has been a vibrant sector, with a number of molded parts growing. But growth has been offset partly by the downgauging of wall thickness. Injection molding growth is being driven partly by new technologies such as insert molding, coinjection, gas-assist, structural foam and thin-wall techniques.
Film extrusion was the second-largest sector in 1999, with 16.8 percent of resin consumed. Its usage has been growing, but downgauging effects have had even more of an impact on actual tonnage processed.
Although some markets, such as industrial stretch wrap are growing fast, new resin developments can mean lower film weight per area for lots of film types.
Plastic resin consumption in the United States grew about 6 percent a year from 1989-99, about 1.5 times faster than the GDP, according to Mooney. Growth would have been even higher if technology had not promoted downgauging.
Mooney is optimistic about plastics' outlook for the next several years.
"People are accepting plastics more around the world," Mooney said in a telephone interview. "They are ideally engineered and cost-effective materials."