DTF-Converted Epson P600: How to Optimize White Ink Flow

Question:
I have an Epson P600 printer converted to use the DTF inks. I put a diaphragm pump on the white ink line between the tank and the filter. A reservoir follows the filter, with an inlet, four outlets to the printhead, and an outlet back to the tank. The pump inflates the dampers when it is turned on. During printing, unwanted white ink drops get wasted on the media over the time the pump runs. Is a peristaltic pump the way to go? What do you recommend?
 
Answer:
Thank you for writing to us with your question. Sorry for being unable to respond sooner. Since printer problems are one of those urgent types of questions, we think the more considered and thoughtful answers would be the best way to go here. BCH Technologies (https://bchtechnologies.com) Thanks for your viewership and support on YouTube (https://youtube.com/@bchtechnologies). Your feedback and support keep us motivated and on the right track to be a better tech and produce quality content about printer repairing.
Now, I'd like to look over your concern in more detail.
 
Understanding the Problem
Based on your description, the diaphragm pump seems to be overpressurizing, inflating the dampers and allowing the white ink to creep into the media. Excessive pressure can lead to an uneven flow of ink that directly compromises print quality.
 
Recommended Solutions
There are two leading solutions to this problem. You can do one or both of these to optimize your white ink system:
 
Install a Secondary Ink Tank
A second tank serves as a pressure damper to prevent spike pressure from the pump from reaching the printhead dampers. This tank has two key functions:

• This function performs the classic function of pressure buffering: it absorbs ink pressure variations and prevents dampers from inflating too much.
• Ink Availability: For long print runs, if the pump cannot keep up for a moment, the tank acts as a buffer and ensures that printing continues seamlessly.

We recommend using this Secondary Tank for the DTF Printhead (3 mm OD) (https://bchtechnologies.com/products/secondary-tank-for-dtf-printhead-3-mm-od-1).

Install a Homing Sensor to Control Pump Activation

This more mechanical version of controlling ink flow uses a homing sensor to determine when to operate the pump. This ensures that the pump does not run when the printhead carriage moves and actively prints.
For instance, we have a Printhead Carriage Homing Sensor for L1800 (https://bchtechnologies.com/products/printhead-carriage-homing-sensor-for-l1800-r1390-customizable-on-off-signals), which could be modified for the P600.
 

• How It Works: The homing sensor has a push-in roller switch. It will only allow the pump to run when the carriage is home if you can mount it onto the frame where it pushes the roller in when parked.
• Circuit Off: When the carriage moves away, the roller is released, the circuit is opened, and the pump stops. This way, the pump just runs when the printhead is not printing, so less ink leaks out.

Are Peristaltic Pumps Right for You?
A diaphragm pump has less stable and controllable ink flow, so a peristaltic pump is better. Rotating rollers squeeze ink through flexible tubing, which may help prevent over-pressurization of the dampers. Switching certainly is an option, but before that, why not give the above solutions a try? They are cost-effective and have worked for other DTF users.
 
Final Considerations
The resolution requires a practical, hands-on approach, test, and evaluation. Unfortunately, we can't help with remote repairs, but you can send your printer to our local diagnostic center (https://bchtechnologies.com/printer-repair-service) for evaluation. Due to high demand, this service works first come, first serve and may take a couple of weeks before we can see your printer.
We also publish online resources for help. Our YouTube channel (https://youtube.com/@bchtechnologies) has plenty of troubleshooting guides. Look under the menu on our channel after clicking on the search icon next to the "About" section to find particular topics. The YouTube algorithm can also suggest related videos from other channels that may help.
We hope you find this information helpful in resolving your problem! Thank you once more for contacting BCH Technologies and for your continued support. Please feel free to always consult our website or our YouTube channel for further guidance.