Unlike cavity pressure measurement, which is established as a defined standard of quality, the advantages of cavity temperature measuring technology are just being discovered.
Cavity temperature sensors are comparatively cost-effective and easily installed, making the new Priamus cavity temperature sensor a viable option. The unit is extremely small (1 by 12.5 mm), and is connected—without a receptacle sleeve and steel conduit—directly to a flexible cable. This construction enables mounting within very small tools, and the reduced size also results in a faster signal elevation.
Placed at the end of fill, the signal is used for automatic switchover to holding pressure. Unlike conventional switchover methods, this process responds to viscosity variations since switchover only occurs at cavity fill.
The same principle is used to control sequential molding applications by placing a temperature sensor after each gate. When melt reaches the sensor, a signal is sent, which either opens or closes the valve gates, depending on melt position.
The system reportedly can be used to balance multicavity or multicomponent hot runner molds. Cavity temperature sensors automatically determine the optimum setting of the controller so that all cavities are filled at the same time. Priamus System Technologies AG, Schaffhausen, Switzerland, +41 52 632 2605; www.priamus.com