Large Temperature Difference System
Inverter-Type Mold Temperature Controller
●The performance of a mold temperature controller depends on the temperature difference of the circulation medium.
●The optimum temperature difference provides both power-saving and stable molding.
Why does a mold temperature controller require high-flow?
We have wondered what no one had wondered before; What would happen if we reduced the flow rate?
A mold temperature controller exchanges the heat. From our study, we have discovered that “Heat Exchange Amount x Flow Rate (Pump Frequency) = Constant”.
In other words, the reduced flow rate does not change the cooling time. The reduced pump frequency did not affect the actual molding as long as the temperature difference was not too large. The example on the right shows that the pump power drops to 30% when simply increasing the out-feed temperature by 1 degree. This power-saving method is called “Large Temperature Difference System” and commonly used in air conditioners.
Why is it possible to save so much power?
The pump power has the characteristics, which are proportional to the cube of the flow rate. The power can be calculated when the frequency of the pump motor is 40Hz in the 60Hz area.
The mold controller temperature with the pump is ideal for power-saving.
What is essential to the high performance of the mold temperature controller?
We have shown that the flow rate was not an important factor. Usually, a mold temperature controller controls to keep the in-feed temperature constant. The set temperature is reached promptly after the operation is started, and the controller keeps the temperature constant as if it were a matter of course. However, dynamic changes are actually happening in the mold.
The graph on the right is a model based on the actual molding test. The in-feed temperature becomes constant in few minutes, however the temperature difference continues to change afterward and even at injecting, cooling, and removing during the continuous molding. If this temperature difference was too large, it would cause great variation in the temperature distribution on the mold as well as insufficient cooling.
(It is recommended for the temperature difference to stay within the range of 5 degrees in Celsius for general molding and 2 degrees for precise molding.)
Thus, it is absolutely essential for a mold temperature controller to maintain the temperature difference within the tolerable range. Conventional mold temperature controllers have been ignoring the issues of the temperature difference, by running the pump in high speed, and wasting the excessive energy.
This inverter type mold temperature controller has achieved both power-saving and stable molding, for the first time, by proactively reducing the flow rate as maintaining the temperature difference with the unique technology.
Visualizing the temperature difference
The employed touch panel visualizes the temperature difference on the screen. The graphical display on the touch panel helps observing the changes over the time or in the molding cycle. It is useful for calculation of the waiting time at start-up, quality management, or investigation on the cause of the defects. The displayed instantaneous power and frequency of the pump can tell you the advantages of the power-saving at a glance.
●GThe time scale is available in 1 second, 10 seconds, 1 minute, 10 minutes, and 1 hour.
●Supporting substantial changes of the temperature difference with the unique maximum temperature difference controlling technology
●Accommodating the molds with large heat radiation (the out-feed temperature is colder)
●Extendability with the adjustable lower and upper limits of frequency
●Functions to link and store the temperature difference setting (SV) on the mold memory (0 through 99)
Storing more than 10,000 hours worth of main data, including the temperature difference and the frequency, during the operation
The automatic graph generating tool is available on the included SD card.
*A PC with “Microsoft Excel (2003 or later)” and the SD card reader are necessary to use the graph tool.
* We recommend using a mold heat shield to avoid wasteful heat radiation.
It is useful especially for speedy start-up and stable molding in engineering plastics.
* There are limitations to the effect of the power-saving per mold, as the overall power-saving on the unit depends on the heat output, which compensates the heat radiation from the mold.
|●Medium Circulation Hose
●24 Hours ON/OFF Timer
|●7-Days (Weekly) Timer
|●Mold memory number reset
●Infrared Remote Controller
●External Start-up Input Terminal
●Water Supply Filter