Ultimate Guide to Restoring White Ink Flow on the L1800 DTF Printer

Question:

A user new to DTF printing noticed that their L1800 Procolored printer, just two months old, is no longer delivering proper white ink flow. Their nozzle check shows only four lines total for both white channels. They have tried several steps-running printhead cleanings, swapping dampers, and other adjustments-but the issue persists. They're looking for recommendations on how to restore proper white ink output.

Answer:

White ink flow issues on L1800-based DTF printers are extremely common because DTF white ink is heavier, thicker, and more prone to sedimentation than standard pigment ink. Let's go step-by-step through the most effective and safest methods to diagnose and restore white ink flow.

1. Ensure the Printhead Is Properly Parked on the Capping Station

To correctly prime the printhead, begin by powering the printer ON. Allow the printhead to move and settle naturally onto the capping station. This is the safest way to confirm it is properly sealed.
If you attempt suction while the printhead is not sealed, you will only draw air rather than ink.

2. Use Controlled Suction Through the Waste Line

You will need a syringe and tubing connected to the printer's waste ink line:

1. With the printhead parked, gently pull 2 ml of air to establish initial flow.

2. Next, slowly draw 4-6 ml.

   • You should feel light resistance.

   • If you draw only air → the printhead is not sealed or the capping station has an air leak.

   • If you feel hard resistance and nothing comes out → the capping station may be clogged. This must be fixed first, or no priming will work.

3. If the nozzles begin to open, you might hear a faint crinkling sound from the damper membranes-this is normal.

4. Continue drawing until the black rubber stopper on the syringe passes the 2 ml mark, then hold for 10 seconds to stabilize the flow.

This controlled suction method works because it gently pulls ink downward through the channels without forcing high pressure that can rupture internal printhead components.

3. Run a Light Cleaning Cycle

After priming:

• Perform one standard cleaning cycle.

• Avoid strong or repeated cleanings for at least 12 hours.
  Over-cleaning can overheat the printhead or flood the capping station, worsening the clog.

• Give the printer time to rest and allow ink to settle into the nozzles again.

4. Install a White Ink Inline Filter

If the priming process restores some flow, it is crucial to prevent future clogs.

Install a white ink filter on the white ink feed line-available at BCH Technologies (https://bchtechnologies.com).
This helps trap undissolved particles before they reach the dampers or nozzles.

5. If Flow Still Doesn't Recover: Deep Cleaning Is Needed

If you still see only partial white output:

• The printhead may require removal and soaking for a deeper cleaning, especially if thickened white ink has reached the nozzle plate.

• Also inspect:

  • Dampers for collapsed membranes

  • Ink lines for sediment buildup

  • The capping station's rubber seal for cracks or warping

  • The pump assembly for blockage

DTF ink buildup progresses quickly, even in newer printers, so catching it early is key.

Addressing printer issues like these often requires hands-on work, and unfortunately, we cannot offer remote troubleshooting or repair support. We do offer in-person diagnosis and repair through our local facility, which you can find here: Printer Repair Service (https://bchtechnologies.com/printer-repair-service). Due to high demand, service is first-come, first-served and may involve a waiting period. Our shop can repair full printers or individual components, and we'll provide clear guidance on next steps. That said, we know our rates are not the most budget-friendly, so we strongly encourage DIY solutions through online resources. Please explore tutorials on YouTube-including our own channel's homepage (https://youtube.com/@bchtechnologies)-and use the search bar next to the "About" tab to find specific topics. With nine years of videos, even I can't remember every one, but YouTube's search recommendations are incredibly helpful.

Thank you again for your question and for taking the time to learn about your equipment. Your engagement helps us continue supporting the community. If you need more clarification, feel free to reach out anytime.