Lien Fa Injection Machinery Company, Ltd.
New Eaton KHDG5V-10 Series Valve Elevated 3000-ton Injection Molding Machine Performance
"Eaton's release of its new size 10 Vickers® KHDG5V valve came just in time for installation on a Lien Fa injection molding machine destined for a GM assembly facility. The solenoid-operated KHDG5V-10 valve, featuring a tailored PQ spool design, is managing six critical control functions that were handled by multiple valves on previous Lien Fa machines."
Eaton proportional directional valves are being used in the production of front bumpers for a GM car model that is assembled in Argentina.
The bumpers are being produced on a 3,000-ton injection molding machine made by Lien Fa Injection Machinery Company, Ltd. in Taichung, Taiwan. The massive machine is equipped with the newly released size 10 Eaton Vickers® KHDG5V two-stage proportional valve that controls clamping and injection functions. Other Eaton products on the machine include Vickers DG5V directional control valves, KCG-3 proportional relief valves, and slip-in cartridge valves.
VKS Hydraulics Company, Ltd, an Eaton distributor in Taiwan, combined its expertise in electro- hydraulic systems for injection molding machines with the Eaton valves to supply just what Lien Fa needed.
Lien Fa has produced more than 2,000 injection molding machines for installation in 60 countries during its 30-year history. Realizing that the valve requirements for the bumper project were a tall order to fill, Lien Fa contacted VKS and competitive product sources to obtain bids on the business.
Although well-versed in LPMC processing and control systems, MECA engineers were unsure of hydraulic requirements for their brainchild, or rules to abide by in terms of hydraulic system design. For this reason, they called on the assistance of Eaton's Duane Jaros, Application and Commercial Engineering (ACE) Industrial engineer, who became an integral member of the project's design team.
Ben Chen, VKS sales manager, and Jones Chang, Eaton sales manager in Taiwan, went into action to sort through the valve parameters. Since the machine would be produced in Taiwan but put to work in Argentina, the end-user wanted its injection molding machine to be equipped with hydraulic components that have global recognition and global distributor support. Knowing that Eaton products have just that, Chen and Chang checked the box.
"Studying the internal working functions of the machine, they learned that the plasticizing process needed to be controlled precisely — a function that would require accurate, repeatable, and smooth transition from velocity into pressure regulation. They also learned that providing the means to move the machine's 20-ton clamp would be a huge technical challenge. But that's not all. The heavyweight clamp would need to move gingerly, quickly, and precisely in order to improve productivity and reduce scrap.
With all the valve requirements identified, Chen and Chang realized Eaton's new KHDG5V-10 valve with a tailored Eaton amplifier card would be a perfect fit for the application. They explained in their proposal how the valve's dynamic capabilities for closed-loop control on pressure, position, and velocity would meet the machine's demanding injection-control requirements, as well as how its 2C spool would achieve smooth clamping control.
The proposal also detailed how the solenoid-operated KHDG5V-10 valve, with its tailored PQ spool design, had the capability to control plasticizing, injection speed, holding pressure, decompression, return, and suck-back pressure — critical control functions managed by multiple valves on previous Lien Fa machines.
With strong faith in Eaton products and the electrohydraulic expertise of VKS, Lien Fa handed the business to VKS, which supplied the required valves within six weeks.
Lien Fa was pleased with VKS' short lead-time and its onsite assistance during machine startup. The customer says the machine's increased control resulting from simplifying valve requirements is a significant advancement, as are achievements of the Eaton valves that include:
- 110 mm per second injection speed
- 0.1 percent weight accuracy of injection volume, in comparison to the previous 4 percent accuracy with a competitive valve
- Smooth clamp movement with +/- 0.1 mm positioning accuracy, in comparison to the previous +/- 0.5 mm accuracy using a competitive valve
PRC, MECA's first SAAM system customer, currently has six SAAM systems in operation, all using a single Eaton power unit to produce shipping containers that are supporting U.S. military troops in Iraq. "Eaton's hardware provides us with 500 tons of force that is distributed evenly over 6-foot square surface areas to convert LPMC sheets into military containers," says John Neate, PRC's process development scientist.
"The four-cylinder hydraulic system supplies the precise closing motion and tonnage needed to produce quality, uniform containers."
PRC's satisfaction with Eaton product-equipped SAAM systems has led to the establishment of SAAM Technologies, a partnership venture between PRC and MECA that became active in 2007.