Synventive Molding Solutions Combining cavity sensors with hot runner valve gate control
USA – Combining cavity sensors with hot runner valve gate control yields new applications and greater process gains. Bill Rousseau, director applications and technical services from Synventive Molding Solutions, analyses each technology and reviews their combination.
There have been a number of advances in hot runner systems and cavity sensors through the years that individually have provided moulders with increased productivity and new capabilities, but if combined, they have the potential to bring even more benefits and capabilities. Let’s take a look at each technology separately and then review the power of the two combined.
Technology, applications for cavity sensors
The manner in which a mould cavity fills will have a huge impact on the quality of the injection-moulded part. Even slight changes to timing, temperature and pressure as the polymer fills the cavity can impact the dimensions, cosmetics and functional strength of the part. However, as important as this filling of a cavity is, the moulder can’t actually see this part of the process. Properly positioned cavity sensors can help solve this dilemma.
The most basic use of these cavity sensors is monitoring the process. The time the melt takes to reach the sensors, as well as the resulting pressure and/or temperature curves, can serve as a reference point for a solid process. Combining pressure and temperature sensors into a single cavity enables otherwise unmeasurable variables such as shear rate, shear stress and viscosity to be calculated, and this data can serve as reference points for troubleshooting or dialing-in a process when a mould is moved to a different moulding machine.