Thermocouples are used to monitor and control the heating zones in the injection mold tools. Hot runner systems will incorporate either ring heaters or cartridge heaters to heat the nozzles to the appropriate temperature recommended by the resin suppliers. Whether the mold is a single cavity or multiple cavity tool the nozzle temperature control is vital to the efficient operation of the injection process.

The sequence of heating the tool and nozzle to operating temperatures is important to the quality of the plastic and to the quality of the part that is made by the tool. If the nozzle is brought up to temperature before the tool reaches operational temperature, the dwell time of heated plastic in the nozzle could degrade the quality of the plastic. It could also lead to the premature failure of the valve pin and lead to leakage and drool of the plastic. The resin supplier will be able to identify the time the resin can be heated before degradation of the plastic. There are several factors that impact this; type of plastic, any filler material, shot size, cycle time, barrel and screw size all are integral.

Thermocouples have three basic criteria for the selection of the appropriate one. The type of “J” or “K”, the diameter, and the length will determine the specific thermocouple required. Thermocouples are good items to keep in your spare parts inventory as a strategy to reduce tool downtime. Please contact us if you have questions, by phone: +1 931-222-4351 or email: sales@fisacorp.com