How Do Hot Runner Thermocouples Solve Molding Defects of Thin-Walled Plastic Parts

The melt fluidity, temperature stability and filling speed of thin-walled injection moulding are required to be very high, and the precision sensing performance of hot runner thermocouples directly determines the yield of thin-walled products such as fast food containers, thin-wall cups and electronic thin-shell parts. Thin-walled components have fast cooling speed and short filling time. If the hot runner temperature deviates significantly, it will produce short shot, flow line, weld line and incomplete edge filling.

Hot runner thermocouples with high precision can detect minute temperature changes of nozzles and manifolds in real time, and feed back to the controller for dynamic power adjustment. Thus, the melt has a constant viscosity during the filling process, and the melt can fill the cavity rapidly and evenly before cooling and solidification. The nozzle tip thermocouple precisely controls the gate temperature, preventing premature freezing of the gate, and providing a constant and consistent flow of melt for high-speed injection.

In the multi-cavity thin-wall mould, the unjustifiable temperature variation between cavities will cause the inconsistency of filling sequence and forming quality. Multi-point thermocouples are reasonably designed to balance the temperature field of the manifold, remove local low temperature areas, assure the consistency of fluidity of melt in each cavity, and make the wall thickness, weight and look of each product highly uniform.

Stable temperature control minimises local overheating of the runner, minimises yellowing, burning and material deterioration of thin wall portions and guarantees surface gloss and mechanical toughness at the same time. Only the corresponding high-precision drift-free thermocouples work along with the hot runner system to finish the stable moulding for ultra-thin-wall products with wall thickness less than 0.5mm, decrease the scrap rate and enhance the production cycle efficiency.