The Influence of Hot Runner Gate Type on Thermocouple Layout Design

In addition to immediately limiting the installation position, angle, type, and number matching of thermocouples-a crucial foundation for early measuring point layout design-different hot runner gate types also influence the melt outlet mode and heat distribution characteristics.

The heat distribution is homogeneous and the temperature fluctuation range is modest for open sprue gates with a straightforward structure and smooth material flow. In order to achieve stable temperature monitoring, thermocouples can be installed in the center steady heating portion of nozzles using a standard installation depth. The layout is simple and requires less amount.

The internal movement of the valve needles in needle valve gates, which are frequently employed in high-precision products, results in intricate local heat transfer, and the temperature in the vicinity of the gate clearly fluctuates when opening and shutting. To effectively prevent faults such wire drawing, material dripping, and gate material solidification, high-sensitivity bent thermocouples must be placed near the front end of the gate to monitor the instantaneous temperature change of melt during switching.

The installation area is constrained and obstructed for side gate and latent gate hot runners due to the mold structure. Short-type angle-adjustable thermocouples must be chosen to avoid structural barriers and precisely reach the appropriate temperature measuring region because conventional straight thermocouples cannot be set in place.

Furthermore, a greater number of auxiliary thermocouples are needed for regional balanced temperature sensing because big thin-film gate hot runners have a wide melt outflow range and noticeable temperature differences in different places. The temperature control impact may be maximized and product molding quality can be fundamentally stabilized by fully integrating the structural features of various gates to create targeted thermocouple layout schemes.