RocTool, a leading developer of mold heating and cooling technologies, has conducted a study to identify a range of resin materials that can use its molding technologies to produce high quality parts with high flow and reduced cavity pressure.
The study is part of the company’s ongoing effort to further develop its HD Plastics material database which is designed to help designers and processors achieve exceptional part quality and increased performance without secondary operations such as painting or decorative films. The database is available to RocTool process users.
RocTool worked in conjunction with RJG Inc, a US company specializes in injection molding training, technology, and resources, to demonstrate the advantages of RocTool's technologies including improved flow, reduced cavity pressure, high surface replication of the mold, and significant gloss improvement.
One of the main challenges in the plastics industry is reducing overall part thickness. The flow increase with RocTool induction heating technology delivers design opportunities and pushes the limits in creating thin-wall applications.
RocTool developed a specific spiral mold to calculate the flow length while pressure sensors were implemented by RJG Inc. to assess the capability of RocTool technology to improve mold filling and reduce cavity pressure. The spiral tool was developed with variable thickness (from 0.5mm to 1.5mm) allowing a complete material characterization.
RJG's process monitoring eDART System collected the data from the sensors which were implemented behind the ejector pin and located close to the gate and at the end of the fill.
"The partnership project provided added value in our ongoing characterization of resins for the HD Plastics material database," said Mathieu Boulanger, RocTool CEO. "This information can be very useful and will provide designers with expanded options. We can now bring this unique data directly to the OEM."
This first study includes six resins covering commodity, premium, and performance categories. Depending on the material, the evaluation revealed that RocTool's molding technologies can double the flow length and reduce the cavity pressure by as much as 72.6% compared to conventional injection molding methods for thin-wall applications.
In addition, the level of mold surface replication climbed to 97.2%, thus providing product designers with a premium look, high gloss, and a matching texture versus traditional molding. The gloss improvement is of particular note in reinforced grades.
The gloss for TPO was measured at 41GU in a conventional process compared to 79GU with RocTool technology. Moreover, strong results were seen with filled materials such as 10% glass-filled polycarbonate (PC) - styrene acrylonitrile (SAN) which had a 130% improvement.