Friedrichshafen, Germany – Momentive Performance Materials has unveiled a new low-temperature cross-linking technology for liquid silicone rubbers (LSR) and its expanded materials portfolio at the Fakuma rubber & plastic show, currently underway in Friedrichshafen.
The Leverkusen, Germany-based manufacturer is presenting LTC-LSR (low temperature cure liquid silicone rubber), which it says cures at 110 °C, a considerably lower temperature than previously available grades.
According to Momentive, tests show that the mould temperature for LTC-LSR can be reduced by 30 °C in comparison without having to extend the heating time.
Instead of reducing the processing temperature, added a company statement, the cross-linking time can alternatively be reduced by up to 45% compared to a standard LSR.
“This opens up new material combinations for LSR, for example with temperature-sensitive thermoplastics,” said Momentive, noting that subsequent tempering would not be required.
Furthermore, the low-temperature properties of the LSR will shorten the production time of parts and reduce the risk of burns during demoulding.
“Once the A and B components of LTC-LSR are mixed, they can be stored and processed at room temperature for over a week, giving high design flexibility for processing procedures,” Momentive added.
The silicones specialist is also presenting new grades of thermally conductive LSRs – NL9360 and NL9330 – which can dissipate high temperatures from sensitive components, for example in electronics applications.
The materials, Momentive said, are particularly suitable for the production of parts in the drive sector or charging management of electric vehicles.
With a hardness of 60 Shore A and optimised for injection moulding, the NL9360 grade combines short processing times with high stability and flexibility, according to Momentive.
In addition, the material has a low compression set of 10% with a thermal conductivity of 1.5 W/mK, nearly five times higher than conventional LSR.
NL9330 is an equally thermally conductive LSR-grade with a hardness of 30 Shore A and a compression set of 9%, also developed for injection moulding.
Both grades, Momentive said, have been specified for the production of heat conducting pads and seals as well as cooling units in the engine compartment of vehicles.
At its Fakuma exhibition stand A4-4307 in Hall A4, Momentive is demonstrating the processing of the new material on an electric Allrounder 470 A injection moulding machine from Arburg. Thick-walled mini frisbee discs (pictured) are produced there using a mould from ACH Solution.