Orlando, Fla. — Sumitomo (SHI) Demag Plastics Machinery North America Inc. introduced a new automatic quick color-change system at NPE2018.
The company showed the color-change technology on an SE50EV-A all-electric press by molding polypropylene vacuum cleaner fan blades during the show May 7-11 in Orlando. The cycle time is 14 seconds.
The color-change system is available as an option on SEEV-A machines. It saves labor by automating the steps from purge to molding. That cuts time and reduces the amount of resin and colorant by 17 percent to make a change, the company said.
An optional image sensor plus the SEEV-A quality control capabilities prevent defective parts from reaching the production line.
A programmable pigment mixer — a Pigmic unit from CAM Co. Ltd. — changes colors prior to the last shot. A color definition camera works with the mixer to log in desired colors and kick out nonconforming parts.
The precision weighing equipment and pigment mixer are installed above the hopper on the injection press. Pigment is fed directly to the screw.
In addition to the color-change system, Sumitomo Demag also rolled out an optional cavity pressure sensor and material temperature sensor inside the mold.
All of the company's molding machines on display showcased the Productivity+ benefits of the presses, which Sumitomo Demag says include advanced technology, applications flexibility and innovation that expands the capabilities of injection molding by increasing throughput, eliminating waste, reducing energy use and improving molder profitability.
Ten of the presses highlighted the Z-Molding advanced motor technology and the flexibility of the SEEV-A platform machines.
In packaging, an all-electric SE180EV-A with 202 tons of clamping force turned out an in-mold labeled container lid using injection compression molding. The two-cavity mold ran with a cycle time of fewer than five seconds. Injection-compression molding of high-speed, thin-wall parts "can achieve results that compare to the thin wall and light weight of thermoformed parts but with the quality and design features of injection molding," said Mike Uhrain, technical sales manager of packaging.
Another packaging demonstration turned out more than 130,000 caps an hour for bottled water on an El-Exis SP hybrid. The 72-cavity mold ran on a cycle time of fewer than two seconds.
Sumitomo Demag also showed gas-assist of an automotive-type part on a SE500EV-A all-electric press with 566 tons of clamping force. The single-cavity, hot runner mold was on loan from Sajar Plastics Inc. The flow length is 23.5 inches. With gas assist, the high density polyethylene part weighs 22.6 ounces vs. the 23.9 ounces the part would weigh without using gas assist.