MANCHESTER, MICH. - Johnson Controls Inc., which already offers wheel blow molding machines with 12 and 14 stations, now is building an eight-station wheel machine. JCI is positioning the Uniloy model as a simple, economical blow molding machine with molds that can be changed easily, thanks to an innovation the company calls ``quick-change, variable mold length.''
``We wanted to expand the marketplace'' for wheel machines, said Jeff Newman, business manager of continuous extrusion blow molders, for both wheel ma-chines and shuttle machines. ``Wheels were perceived as a dedicated, high-volume machine,'' Newman said.
Blow molding companies would use a wheel machine to pump out a single product, such as motor oil bottles. More flexible and less expensive, the new eight-station machine is suited for molders that want shorter runs, or that serve smaller markets.
For example, the eight-station wheel machine can mold 70-75 motor oil bottles a minute using a dual parison, compared with 125-140 bottles for Johnson Controls' 14-station wheel.
Warren Distribution Inc. of Omaha, Neb., bought the first Uniloy eight-mold machine, to mold antifreeze bottles. The machine was running during an open house at JCI's Plastics Machinery Division in Manchester, March 4-8.
Wheel machines have molds mounted to a wheel. As the wheel rotates, each mold mechanically opens and shuts, clamping off a parison continuously extruded down. As the molds come up the other side of the wheel, they open and a device with suction cups removes the bottle and places it on a conveyor, which moves the bottles to a machine that trims flash and finishes the neck.
The complete system costs about $900,000, excluding molds, Newman said. The firm hopes to sell six to 12 a year.
The machine can run one or two parisons. Designers condensed the frame of the machine, giving it a smaller overall footprint. They also replaced a round takeout belt with an oval one, decreasing cycle times by about 10 seconds, Newman said.
But the key changes will enable users of the eight-station machine to change molds, putting in longer or shorter molds, without changing cams. In the new design, the cam is fixed to a slide plate that can be unbolted easily, moved out to accept a longer mold, and bolted together again. Previously, the mechanism was attached to the lower mold platen assembly, meaning any mold size change required a new cam.
Similarly, on the other side of the mold, the over-toggle mechanism had been attached to the mold platen, meaning the cam would have to move out if the mold was moved out. Now the mechanism is fixed to a mounting plate. The cam does not change. Instead, the upper interlocking hook can be replaced with a longer hook to accommodate bigger molds.
Newman expects good export sales in countries with small markets where molders want to make different products on the same machine.
``The machine was designed as a metric machine because we feel there's going to be as much potential outside the U.S. as there will be in the U.S.,'' Newman said.