German auto supplier RÃ¶chling Automotive Group has created a new way to mold parts, replacing the nitrogen used in gas-assisted injection molding with a solid object in a process it calls ``Projectile Injection Technology.''
The company began production of coolant pipes for the BMW 3 Series vehicles in September and also has future business lined up with other European automakers, said Marlene Rinner, head of PIT development.
The system turns out parts with thinner walls than would be capable with either gas- or water-assisted injection molding, and with a constant inside diameter within the pipes, she said.
It also employs the same equipment used in gas-assist injection molding, so the company did not have to invest in new presses. However, it does tap into a proprietary mold and projectile developed by RÃ¶chling, Rinner said in a July 20 telephone interview.
The finished part gives the Mannheim, Germany-based company tighter control on what happens inside the mold as the part is hollowed out by the projectile, she said. The finished product can weigh half as much as a similar pipe produced with gas-assist technology because of the thinner wall structure.
PIT came from a brainstorming session in 2000 of RÃ¶chling engineers where ways were considered to make pipe and other complex parts beyond gas-assist injection molding and blow molding. One of the engineers said it would be ideal if a bullet could be fired through the plastic and tunnel an opening, prompting the deliberations that lead to the technology, Rinner said.
The company spent more than two years in development before it began taking the concept to its customers, Rinner said. BMW signed on in 2003.
The technology allows the firm to still make parts that offer all of the in-mold connections, brackets and features of an injection molded part, but also fit with the complex geometry required within the engine compartment. It does not need a special resin and has a shorter cycle time than gas- or water-assist molding, she said.
The process won the grand innovation award from the Society of Plastics Engineers Central Europe division earlier this year.