Hello,

It is normal to have leakage current in the nozzle pump. In order to remove this current from the system, the pump must be grounded. But I see that your main problem is that the pump is exposed to the electric field. Moving the pump away from the electric field as much as possible will reduce this leakage current. You may want to consider pumping the solution into the nozzle with a PTFE or PE hose. Also make sure the power supply is grounded and ground or negative high voltage must be connected to the collector. We can help you better if you picture how you set up.

Best regards.

The attached figure is taken from the article below.

https://www.researchgate.net/publication/322897793_Plasma_Modification_of_Poly_Lactic_Acid_Solutions_to_Generate_High_Quality_Electrospun_PLA_Nanofibers

Hello Behzat YILDIRIM ,

Thank you for your reply.

The pump and the power supply are grounded, and negative high voltage is connected to the collector.

I have a PTFE tube in my set-up. Also, I moved the pump away from the electric field as much as possible by the PTFE tube, but I still have the problem and the pump makes a lot of noise.

Does this leakage affect the pump performance?

Even by keeping the voltage at a certain value, after a few minutes, the leakage current suddenly increases sharply.

I attached a video and an image of my set-up.

https://iutbox.iut.ac.ir/index.php/s/neHotkNHM5TYYoe

Best Regards

Hello Mahsa Ahmadi

Hi,

I checked your setup. I couldn't see that the pump was grounded. You must ground the pump with an additional cable. The high voltage reaches the syringe with the solution and creates an electric field. Leakage current cannot prevent the operation of the pump, but after a while, it may cause a malfunction in the pump motor.

The pump distance in the video is sufficient. I suggest you check your power supply cables. If it doesn't get too high, 10-20 microamper leakage current is not a problem.

Is your setup as I mentioned in the attachment?

Hello Behzat YILDIRIM ,

Thank you for your detailed answer.

The power cable of the pump is connected to ground (image attached).

Do I need to create an additional ground wire? How should I do this?

I checked the ground cable of the High Voltage power supply. It is intact. My High Voltage power supply is a little different from your attachment. I attached a video and 2 images of it.

https://iutbox.iut.ac.ir/index.php/s/Ffp8Wen3wkS3z3t

some times I have 100% current (0.75 mA) with my solution !!

Best regards

Hello Mahsa Ahmadi

I will suggest a phased practice test to exact the problem.

First, position it with your positive power supply connected to the needle tip. Ground the collector to discharge the load. Set the Type to collector distance to 20 cm. Operate without the feed pump installed. If there is no leakage current, the problem is not in your power supply or grounding system.

Secondly, if the previous installation was successful, include the feeding pump in the system. Connect the feeding pump to the needle tip with a hose. Also, ground the chassis of the feed pump close to the syringe. You can make grounding by multiplexing the grounding cable you use for the power supply.

I think the problem in your system is caused by your power supply or grounding. If you don't have a problem in the first phase, there should be no problem in the second phase. If you have problems at the first stage, contact SKE company to solve the problem with your power supply or grounding system.

I also want to ask. Do you have a grounding system different from the electrical network of the building?

Best regards

Hello Behzat YILDIRIM ,

Thank you for your help and sorry for my delay.

I performed the tests according to your instructions.

I did not have any problem with the first test, which indicates that the power supply is ok.

In the second test, the leakage current started when I add the feeding pump to the system.

But the feeding pump only is grounded by the power cable and we only use the grounding system of the electrical network of the building. Is the ground connection of the power cable not enough for electrospinning??

How can I ground the pump with an additional cable?

In the image you attached, you ground using an additional cable. May I ask where the end of the cable is connected? And did you drill the pump?

Could you please guide me more about the making ground for the feeding pump?

Best regards

Mahsa

Hello Mahsa Ahmadi

Unfortunately, the ground connection of the electrical cable is not sufficient for electrospinning. If you still want to test it, connect two separate wires to the end of your ground wire. You can use one ground wire to ground the power supply and the other to ground your supply pump. In the attached image, you can use the yellow wire in the middle as the ground wire.

We use our own grounding system in the laboratory. We use it where grounding is required by connecting a large number of cables to the end of our ground cable. Ground wires can be used in pump, power supplies or collector.

No need to pierce your pump. You need to connect the cable to the metal part of the pump. You can connect your ground wire to an external bolt of your pump. Thus, the skeleton of the pump will be grounded.

The grounding system used in the electrospinning process must be good. Researchers often have problems when using the building's ground connection. For this reason, an external grounding system must be prepared for electropinning.

If your leakage current problem persists as a result of the trials, I recommend you to prepare a grounding system.

Best regards