Large-tonnage injection molding machines were not much in demand 30 years ago, especially among custom molders. Many of them were used for large-part molding for automotive/transportation, appliance and industrial applications. Many custom molders didn’t like going much beyond the 400-ton range, with 500-ton presses being their top-end limit because of the expense of plant infrastructure to accommodate not only the presses but the large molds, as well.
Over the past decade, the dynamic has changed, as demand for large parts has increased concomitant with advances in metal-to-plastic conversions, improved properties in engineering thermoplastics and the ability of machinery manufacturers to build large, energy-efficient machines that offer fast cycle times. While exact statistics on the number of large-tonnage press shipments were not made available to PlasticsToday, the Plastics Industry Association did tell us that “shipments of large machines have increased more than smaller presses.”
Dale Evans, President of Evco Plastics (DeForest, WI), told PlasticsToday that his company recently purchased several large-tonnage machines, bringing its total to 31 presses that exceed 1,000 tons out of the company’s 186 machines. Evans said he considers the term “large tonnage” to apply to presses of 1,000 tons and higher. “Our large-tonnage work represents about one-third of the company’s total sales,” Evans said.
|Large-tonnage Engel injection molding machine and mold at one of Evco's Mexican plants.|
Evans explained that he originally got into large-part molding as a strategy to compete with China, because large parts are more costly to ship long distances. “Now we’re in China with a molding facility, so that strategy has shifted,” he said. “But we want to be a local option for our large-part customers.”
Large-tonnage machines have given Evco some good business opportunities over the past few decades to grow the company in various markets, including agriculture, lawn and garden, power sports and automotive. Evco’s history with large-tonnage machines began in 1981, with its purchase of a 1,000-ton hydraulic press. “That machine lasted us a long time and got us into the 1,000-ton range for our molding operations,” Evans said. “In the 1990s, we bought a used 2,500-ton Farrell built in 1973—again, a large but simple machine to operate. The 2000s came around and we retired the Farrell and bought a 3,300-ton Van Dorn for our polypropylene business. We also started running our first 100,000-pound mold at that time.”
Large-part molding means that shipping becomes a “huge factor,” Evans said. “Evco has a lot of smaller plants in different geographic regions that allowed us to get into large-part work at these locations. You’ve got to be close to clients to minimize the cost of shipping these big parts.”
Evco’s large-part molding business keeps growing. Recently, it installed a 2,500-ton machine at its Calhoun, GA, plant, and three 2,000 ton machines were delivered to a Mexico facility. Another 2,000 ton press is on order for a plant in the United States and another one for Mexico. Evans said the company has five presses in the 3,000 ton range.
Getting into the business of molding very large parts requiring presses of 1,000 tons or more takes a lot of strategic planning. “When you decide to go into big machines you have to be prepared,” Evans explained. “You can’t just install one of these large presses in the plant alongside your smaller presses. Special infrastructure has to be put in place, such as reinforced concrete floors, large cranes for mold handling and more.”