MGS Manufacturing Group has taken its experience in developing technology to injection mold two materials, like coinjection and two-shot, and moved into a new arena: equipment to injection blow mold PET bottles with a barrier layer.
John Hahn, vice president of engineering, said blow molders asked MGS to build equipment for their sector. He said MGS is willing to try new things, which is attractive to customers.
``We don't tell them no. We tell them yes,'' Hahn said. In this case, MGS uses two injection units - one mounted on the moving platen, the other on the fixed platen.
The company in Germantown, Wis., is very diverse. MGS makes molds, does plastics processing and builds equipment such as bolt-on injection units, rotating platens and indexing plates.
MGS said its experience in coinjection molding, also known as sandwich molding, means the company understands how two materials will flow and interact with each other.
MGS has applied for a patent on its barrier-layer process. The technology, which MGS plans to show at NPE 2006, can be retrofitted onto traditional, single-stage blow molding presses, where one machine injection molds the preforms, then blow molds the container. The MGS system also can be added to conventional injection molding machines, according to Hahn.
``We have basic knowledge to draw from,'' said marketing director John Berg. ``All we did was reconfigure it for something different.''
MGS' process is similar to injection blow molding, but with the addition of a second injection unit and a valve pin, also known as a stuffer pin, the company said. The first injection unit is mounted on the moving platen; the second injection unit mounts on the stationary platen.
The first injection unit injects the main PET resin into the runner. Then, the second unit adds the barrier resin, which flows inside the main resin.
After both materials are injected into the mold, the stuffer pin moves forward to push all the resin into the preform mold. MGS said this eliminates all scrap.
Hahn said the technology is not just for PET bottles but can work for blow molded containers using other materials as well.