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How efficient are Yizumi machines?

STV Machinery News and PR from STV Machinery - Published 04 February 2019 How much energy can I save with your Yizumi machines? The typical answer youll see around the industry is up to 80% - We did our own test to see if it's true.

Background information - Servo drive vs variable displacement

Older machines in our industry (80’s & early 90’s) used a standard constant pump, then variable displacement pumps (which are still commonly seen today) came in and now we’re dealing with servo driven pumps. Each was an improvement on the last in terms of efficiency and it is the most recent two technologies we’re going to compare. The reason we expect to see an energy saving with servo drive is illustrated in the graph.

In the illustration you should be able to see where the energy saving from this technology is achieved. During points in the cycle where little or no pressure is required from the pump, the energy consumption drops off to almost zero. This combined with the fact that the servo drive in Yizumi machines can deliver maximum torque incredibly quickly, means that the energy saving potential is maximised at every point of the cycle. The constant drive cannot alter its pressure delivery and the variable displacement pump does not react as quickly as the servo drive.

To separate energy saving myth from fact, we decided to test a servo driven machine against a variable displacement pump machine in our workshop. The facts of the test;

Same tool used in both machines (one after the other obviously)
Set to the same cycle time (16 secs)
2.7 seconds mould close time
3.1 seconds for carriage movement and injection
6 seconds cooling & holding
2.2 seconds mould opening
2 seconds open & ejecting
Same temperature setting on the barrel heats
The test was started once the machines were warmed up with the oil temperature and barrel heats at the same set points.
Energy monitor was reset to zero and the test started on mould close after 5 cycles
Duration of the test was 2 minutes

Machine one

Yizumi UN60A5 295/600

60T clamp force
Manufactured 2017
40 run hours
Servo driven pump
35mm screw
159g shot weight

Machine two

European manufactured

55T clamp force
Manufactured 2005
2600 run hours
Variable displacement pump
38mm screw
122g shot weight

The test
The results

As can be seen in the video above, the servo drive equipped Yizumi machine required 0.056 kW of energy over the two minutes compared to 0.345 kW of energy for the variable displacement pump equipped machine. That equates to 1.68kWh for the Yizumi and 10.35kWh for the other manufacturer.
That's an energy saving of 83.76%!!!

With this type of saving, we anticipate and appreciate scepticism. We did this test to satisfy our own curiosity and assumed others may have the same burning question.

There is no doubt that a few holes can be found in our methodology (we’re not scientists after all), but we think it’s a good relatable example.

We’ve demonstrated that a massive energy saving is possible, but it depends on the characteristics of the cycle. We’ll be doing more tests on larger machines soon.
Energy savings of up to 83.76% possible with Yizumi machines.

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