A highlight at Chinaplas in Shenzhen last week — and an indicator of the technological advances made by Chinese injection molding machine builders — was on display at the Yizumi stand. The machine OEM teamed up with Dongri RIM Machinery to develop a production cell that manufactures two-shot injection-molded parts with a thin 0.3-mm-polyurethane (PU) coating applied in mold via reaction injection molding. What’s more, if the component is scratched, running hot water over it for 10 seconds makes the scratch disappear as the coating layer self-heals.
The Liming Research Institute of Chemical Industry and auto electronics firm Kostal also participated in development of the technology, dubbed ReactPro. The system is centered on a Yizumi UN260-C-BTP 260-tonne injection press and primarily targets automotive applications.
The PU coating can also be used to generate various other product effects, such as 3D depth and patterns. Further, in-mold labeling can be incorporated in the process. At Chinaplas, the production cell was molding coated and uncoated parts weighing 56 grams each in a two-cavity vertical rotary table tool at a cycle time of 56 seconds.
Yizumi also showcased its two-platen UN500D1-E injection press at Chinaplas. The hybrid machine features an electric clamping unit and was demonstrated molding a large panel measuring 456 x 125 x 200 mm for a car side door from ABS (80-gram shot weight at a 90-second cycle time).
Rounding out the display was an all-electric FF200 injection unit molding LED lenses from PMMA resin using a laser-based gate cutter, and a PAC250M press for medical applications that molded polystyrene petri dishes in an eight-cavity mold.