Evaluate the injection moldability of plastic melt with Therma-flo™ Material Characterization.
The first material characterization method for evaluating the injection moldability of a plastic melt, Therma-flo™ Moldometer maps how a material will mold through various geometries and processes.
As a patented method and apparatus, Beaumont’s Therma-flo™ material characterization method is quite different from older technologies that only provide extrusion based isothermal flow characteristics of a melt. These older MFI and rheometer methods totally omit evaluating the thermal exchange that happens between the melt and the mold during mold filling.
The Therma-flo™ material characterization method:
- Provides a detailed analysis of how a polymer melt behaves during injection molding
- Material characterization data is provided in easy to interpret terms that are easily applied to both the lab and the shop floor
- Captures both the rheological and thermo-dynamic characteristics of a melt as experienced during injection molding
- Evaluates the impact that flow rates, melt temperatures and cavity geometries have on flow under these non-isothermal conditions
- Includes use of cooled flow channels as normally found in actual injection molding, allowing for the normal thermal exchange between melt and mold and the formation of a frozen layer
- Uses realistic injection flow rates, melt temperatures, flow-channel temperatures and flow-channel geometries based on those found during normal injection molding
How Therma-flo™ works
Therma-flo™ is part of a fully integrated and semi-automated test cell that includes the moldometer tooling, a high-performance injection molding machine with specially developed controls and a high speed data-collection system. The patented method evaluates a polymer’s flow behavior through a wide range of cavity geometries. Standard characterization channels range in thickness from 0.020 to 0.120 inch. However, the patented cartridge system allows for characterization at thickness as small as 0.008” to thicker 0.160”, and runner channel diameters ranging from 0.040” to 0.180” channels. The plastic melt is characterized through each of the molding channels at up to 10 injection rates and multiple melt temperatures. Flow velocity and melt pressures are captured directly through the highly instrumented tooling using an integrated high-speed data-collection system developed by our controls team. Specialized cartridges allow characterization of thin-wall and micro-molding, high-flow materials such as LCPs, powdered metals as well as a special automotive cartridge.
Figure 1 shows one form of a Therma-flo™ Moldometer data graph developed for resin distributor Nexeo Solutions. This graph contrasts the molding characteristics of a material through five different cavity thicknesses. Data also can be selectively displayed to show the impact of melt temperature on molding and to contrast the molding characteristics of multiple materials through various thicknesses and temperatures.