Technical Corner is a quarterly series featuring updates from Forum Plastic's process engineers on key topics in mold design and fabrication.
Medical manufacturer requirements are evolving as technologies advance, and the selection of materials for a medical device can be a challenge for a successful product launch. Many factors must be considered, including material structure, processing and properties.
That’s why Forum engages with manufacturers early in the product development stages, and we maintain strong relationships with our engineered resin suppliers.
Recently, one of our medical device customers issued Forum purchase orders to mold parts out of PEEK, or Polyetheretherketone. These parts are critical to the successful operation of a medical device. Needless to say, there are many tight tolerances that need to be held.
Molding PEEK requires mold steel temperatures ranging from 338⁰F to 392⁰F, machine barrel temperatures in the range of 662⁰F-752⁰F, and material drying temperatures of 302⁰F-320⁰F. Proper mold temperature is critical when molding PEEK to achieve the required material semi-crystalline state.
We are committed to adapting to meet the evolving needs of our customers, and as such, Forum has the equipment and knowledge to successfully mold PEEK. For example, we invested in Regloplas hot oil temperature controllers which are integrated into our Arburg molding machines controller.
Knowing the importance of mold steel temperature, a number of thermocouples were added to the mold to verify actual cavity steel temperatures in real-time. These temperatures are monitored via an RJG system that can allow our engineers to monitor cavity steel temperature in each and every cycle of the mold. We can also place a tolerance and an alarm on the temperatures of the cavities to ensure proper cavity steel temperature throughout a production run.
Additional thermocouples were also added to the cavities to control the mold hot oil temperature controller. These thermocouples are interfaced to our molding machine. The molding machine is then interfaced to our hot oil controller. Mold temperature setpoints are now set along with tolerances via the molding machine controller. By doing this, the temperature of the hot oil controller is derived and controlled via the actual cavity steel temperature.
A Comprehensive Approach to Injection Molding
Forum Plastics takes a comprehensive approach to injection molding using scientific molding principles. We collect all of the necessary data and parameters to develop the best manufacturing solution fit for your end-product application. This includes everything from material properties, melt, fill and cooling rates, pack and hold pressure, and much more. As seen in the example above, we can ensure that the proper cavity steel is maintained throughout the production run.
Forum’s robust capabilities translate to a consistent and repeatable process with every step in the injection molding manufacturing procedure. To learn more about Forum Plastic’s mold design and fabrication capabilities, please visit our website.
Author: Kurt Weber is a senior process engineer at Forum Plastics with over 40 years of injection molding experience.