Evco has built plant additions with the required infrastructure, such as 80-ton cranes that can handle 160,000-pound molds. The company also runs 40-ton cranes over the top of the 80-ton cranes to permit mold changes. “You can’t easily ship 40,000+ pounds of tooling. The molds have to be split in two and shipped on separate trucks,” Evans added. “All of this infrastructure and additional planning takes up a lot of resources.”
Tooling operations have to be put in place to handle these large molds when maintenance and repairs are required. Evco has most of its molds built in the United States and uses moldmakers close to its molding facilities to help service the molds.
Additionally, safety is a “huge issue” when handling large molds, said Evans. “We spend a lot of time ensuring all this equipment is safe, and that our team takes proper precautions when maneuvering large tools,” he added.
Molding large parts also requires a lot of material per shot. “We’re shooting a lot of material,” Evans said. “Our largest machine can mold a 77-pound part, so if you don’t use the material fast enough it degrades in the barrel. With PP or PE, it isn’t much of a problem, but with engineering-grade resins you have to have the appropriate barrel size to match the part, not the machine.”
Evco purchases mostly Engel large-tonnage machines, along with some from Ube and Milacron to stay consistent from plant-to-plant. In addition to its headquarters plant in DeForest, Evco operates two other molding facilities in DeForest, a plant in Oshkosh, WI, and another in Calhoun, GA. The company also has three plants in Mexico—two in Monterrey and one in Juarez—and one in Dongguan, China. For its machines under 1,000 tons, Evco buys electric presses, but for the large-tonnage models, that tend to be “energy hogs,” Evans chooses servo hydraulics because of efficiency. “The big machine market has become more competitive, as more and more companies are getting into large-part molding work,” Evans said.
Proof of that was the successful showing of the many large-tonnage presses from nearly all the machinery makers at NPE2018. Milacron touted that it was showcasing the largest tonnage injection molding machine ever at an NPE show—the Cincinnati—at a “whopping” 2,250 tons of clamping force.
Engel ran a 1,000-metric-ton press at NPE, molding an automotive part.
KraussMaffei showed off its GX series 900-metric-ton press molding 20-liter buckets in a two-cavity mold doing in-mold labeling.
Nissei Plastics Industrial Co. Ltd. announced at the show that it had expanded its molding machinery assembly facility in San Antonio, TX, to accommodate the company’s focus on medium- to large-tonnage presses. Nissei will assemble 500- to 1,300-ton presses at the facility. Future plans call for the company to build large-scale hybrid injection molding machines up to 3,000 tons.
While large-tonnage injection molding machines require some big investments in infrastructure, the markets that require large parts offer some great business opportunities to molders, like Evco, willing to make that leap.