Device measures temperature of in-barrel molten plastic

Dec. 9, 2020
A new technology available through Schmit Prototypes allows injection molders to measure the temperature of the melt, without causing the melt to solidify — a possibility common to previous approaches.

Melt temperature measurement system This new system features a pyrometer and thermocouple probe that can be used to measure very small amounts of plastic in its molten stage. Central to the process is a disposable insulator cup, made out of plastic, into which the specimen is directed. The cup positions the probe in the path of  the melt, and it maintains the temperature of the specimen so that it cannot cool or solidify. One thermocouple probe is needed for the process; a second, spare thermocouple, also is provided.  (For a video about the process, visit

What’s new? The system’s ability to provide insight into the actual temperature of in-the-barrel melt. Through a partnership with Schmit Prototypes, inventor Rich Bleck, a retired process engineer with decades in the plastics industry, has been marketing the system for the past few months.  

Benefits Insight into the actual measurement of the melt, as well as shot-to-shot, operator-to-operator process and measurement repeatability, using a thimble-sized specimen weighing in at just 0.8 ounce. It works with shot sizes ranging from less than an ounce to 10 pounds. The system, which works without operators coming into contact with the melt, is safe, easy to use and accurate, without the possibility of human error.  

Schmit Prototypes, Menomonie, Wis., 715-235-8474,