York, S.C. — Bluestar Silicones USA Corp. is ready to shake up the LSR industry with a new silicone processing system.
Dubbed LSR Select, the system gives molders more control over the cure profile, allowing them to adjust the levels of inhibitor and catalyst in process.
LSR Select changes the way the inhibitor and catalyst are injected into the mold. A traditional process takes two components, Part A and B, and flows them through a pump into a static mixer and are injected into the mold. This process is kit-matched and must go in the same way with the same batch. Getting ratios to be exactly perfect to have full utilization of the silicone product is an ongoing issue with many molders, North American President Christopher York said.
"This hasn't changed since LSR began 35 or 40 years ago," he said. "It's been an A component, B component, match kits forever. All the optimization on the equipment side, the press, the molds and the pumps, are all maxed out. This is so unique for the industry right now, the molders don't know what to think because it is a complete game-changing technology."
What LSR Select does is switch when the catalyst and inhibitor are mixed. Instead of mixing a Part A and Part B together, the molder takes an LSR compound that contains the minimum amount of inhibitor in the base chemistry. That is then mixed in line with whatever additional inhibitor is needed followed by a platinum catalyst immediately before molding. The result is molders now have control of how much inhibitor and catalyst are injected in-line to optimize cure kinetics and efficiency.
"This is like the jump from a pager to a cell phone," said Todd Lawrence, a research assistant at the York facility who helped oversee the development of this process. "We've cut down the amount of material that it takes to get from this point to the injector screw."
Bluestar will provide the chemistry and developed the system. The firm partnered with Elmet, an Austrian-based silicone systems producer, to bring the machinery to life. Bluestar said LSR Select is projected to be operational at its York facility in June.
Elmet said in an email that LSR Select gives processors flexibility. For example, sometimes LSR cures too fast and the mold temperature has to be reduced to avoid problems and sometimes it cures too slow even though the mold temperature is already very high.
Either way, the result is a longer cycle time. Elmet said LSR Select will help ease both problems.
"It's very user-friendly and accessible," Lawrence said. "We didn't have to have an additional cabinet to control all the functions of this. [Elmet] really simplified it; they figured out how to dose while the material's flowing, not preload and shoot."
Karen O'Keefe, Bluestar Silicones elastomers business director, said productivity improvements vary depending on the durometer and part, but can range anywhere from 10-50 percent.
"When you think of a product like baby bottle nipples, that's a consumer-oriented product," she said.
"You just can't get the price point any lower, especially for consumer goods that are highly price-sensitive," O'Keefe said. "Improvement in productivity is really the only way to help address the cost pressures without sacrificing that margin at the molder level."
The single-base system reduces downtime and eliminates the need for kit matching. And producing more parts per press reduces capital investment.