Mold Cavity Pressure Measurement

Plastic Injection Molding Challenges

Transfer

Overseas manufacturing makes it difficult to start new mass production.

Quality

Discrepancies in quality and workmanship of individual parts.

Time

It takes a lot of time to inspect and sort short mold defects.

Track

Unable to achieve mold-by-mold traceability.

Do you want to improve the quality of your plastic molded parts?

MinebeaMitsumi's Mold Cavity Pressure Sensing Components

You can standardize and manage molding quality by understanding the in-mold resin pressure waveform

MinebeaMitsumi’s integrated cavity pressure sensing system can easily and inexpensively measure, manage, and record the “in-mold resin pressure waveform” and “in-mold cavity temperature waveform,” which are important parameters directly connected to the quality of molded products. Pass/fail evaluation and analog voltage output can be achieved by the amplifier alone. For mass production operations, a PC is only required for initial settings.

In-mold Resin Pressure Measurement Principle

The force inside the cavity that pushes out the E pin is measured and converted into a pressure value based on the set area of the E pin tip. The necessary processing on the mold is simple, requiring only the ejector plate.

Short mold detection supports cost savings

By utilizing a cavity pressure sensor with high accuracy and sensitivity, even minute short molds such as scratches can be reliably detected.

Realize cost savings by converting 100% appearance inspection to sampling inspection
Save time by turning microscopic evaluation into a simple visual inspection

Cavity Pressure Sensor with 4 Unique Gauges

We develop, manufacture and test strain gauges in-house. By miniaturizing the cavity pressure sensors, we have achieved a 4-gauge system with small strain gauge sensors.

1/4 the amount of strain compared to a single gauge solution
Minimizes the effect on molded products.(Convex shape of E pin part)
Reduced mechanical fatigue increases lifespan. (Internal pressure sensor: 1 million times at rated load, ∞ times at 70% of rated load)
Variations in measured values due to mold temperature changes are reduced.

FAQ's

Can the in-mold resin pressure waveform be output to the molding machine?

Analog voltage is output from the amplifier. If the molding machine has a function that can import this value, it is possible to output the waveform to the molding machine.

Is the actual cavity pressure monitoring performed at multiple locations in the mold? Will you manage the setting targets for each?

If multiple cavities are installed, please install the sensor at the same location in each cavity. Using the standard cavity waveform as the setting target, we set up a monitoring frame and perform balance and pass/fail judgments for each cavity.

Do you have any idea how many load cells are required for the molded product?

It depends on the size of the product, however it is often placed on the ejector pin, which is prone to short molds. When using it for condition determination, etc., please install it near the gate and near the anti-gate, and first check the correlation.

Is it possible to link with the molding machine after detecting a defect with the internal pressure sensor?

If a defect is detected, an external alarm signal will be sent, so it can be linked with the molding machine and take-out machine.

Have another question? Contact us to learn more about how we can help.