Blow Molding: Injection-Blow Molder Gets a Speed Boost

Closed-loop hydraulics trim dry-cycle times of Jomar’s mid-size injection-blow molder.

Related Topics:

At Chinaplas last month, Jomar Corp., Egg Harbor Township, N.J., introduced the TechnoDrive 65 injection-blow molding machine. It’s a faster version of the company’s Model 65, with 52-ton preform clamp. It has a dry-cycle time of only 1.8 sec, a full second faster than the Model 65. According to Jomar, what makes this possible is a  closed-loop hydraulic-cylinder system on the clamp, which provides so much tighter control of position and speed that the clamp can move much faster without the “slamming” that might otherwise occur. In fact, the clamp stops at mold touch, then completes closing and pressure buildup. The result is fast closing while prolonging the life of molds and reducing jarring of cylinder seals, one of the main causes of oil leaks.

The closed-loop clamping system is adapted from Jomar’s new IntelliDrive models of 72 to 175 tons, which use hydraulic pumps with servo and variable-frequency drives on the injection and clamp, respectively. For the 50-hp drive of the TechnoDrive 65, servo and VFD pumps are not cost-effective, according to Jomar.

Both IntelliDrive and TechnoDrive presses use a radial piston motor on the plasticating screw, which has superior durability and 11% greater efficiency, the company says. Both types of machines also have remote-access capabilities that allow Jomar’s service department to connect with the machine via the internet.