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3 Common NJP800C Capsule Filling Problems That Affect Production Efficiency — And How to Fix Them
1. Capsule Misalignment & Feeding Issues: Causes & Solutions
Problem 1: Improper Adjustment of the Capsule Feeding Platform
Symptoms
During the capsule feeding and separating step, empty capsules may shift sideways, jam in the guide rails, or fail to seat properly in the filling die, resulting in misaligned or rejected capsules.
Solutions
✅ Adjust the guide rail width
Verify that the capsule guide rail width is 0.5–1 mm wider than the capsule shell.
Too tight → Capsules become jammed or damaged during transport.
Too loose → Capsules shift left/right, causing misalignment in the die.
✅ Ensure accurate capsule orientation
Check the capsule sorting mechanism and vibratory feeder to ensure consistent orientation of cap and body.
✅ Check the clamping and indexing system
Confirm the filling platform cylinder clamps the capsules firmly at the end of the indexing stroke to prevent movement during dosing.
Problem 2: Filling Hopper Temperature & Humidity Too High
Symptoms
Powder clumping and inconsistent flow in the hopper cause the NJP800C’s dosing system to feed unevenly, leading to capsule weight swings and unstable running paths.
Solutions
✅ Lower the ambient temperature/humidity
Excessive heat or moisture causes hygroscopic powders to clump, disrupting uniform feeding. Maintain hopper conditions within the powder’s recommended RH range.
✅ Check hopper and agitator alignment
Confirm the agitator and dosing disk are parallel to avoid uneven powder distribution that causes bridging and inconsistent filling.
2. Incomplete Capsule Filling: Causes & Solutions
Problem 1: Edge Dosing Wells Not Fully Filled
Symptoms
Capsules positioned at the outer edges of the filling die have significantly under-dosed weights, while central wells appear normal.
Solutions
✅ Check the powder leveling mechanism
If the scraper or leveling plate does not seat tightly against the dosing disk, powder will not fill the edge wells sufficiently.
✅ Inspect for powder bridging and flow issues
Poor powder flow or air entrapment in the hopper can starve the outer dosing positions. Improve powder flow with granulation or adjust the agitator speed to prevent uneven distribution.
Problem 2: Middle Dosing Wells Not Fully Filled
Symptoms
Capsules in the center of the die are poorly filled, with inconsistent or low weights, even as edge wells perform normally.
Solutions
✅ Adjust the hopper height and agitator position
Set the hopper outlet 2–3 mm above the dosing disk, and the agitator blade 3–4 mm above the disk surface.
This prevents powder from compacting in the center and ensures uniform flow to all dosing wells.
✅ Calibrate the tamping pin depth
Adjust the tamping stroke to ensure consistent compression of powder in the middle wells, eliminating loose, under-filled doses.
3. Poor Capsule Sealing & Closing: Causes & Solutions
Problem 1: Capsule Misclosure or Capping Issues
Symptoms
Capsules fail to lock properly, leading to loose caps, split bodies, or high rates of rejected units after the closing station.
Solutions
✅ Check the closing plate alignment
Ensure the upper and lower closing dies are parallel and centered to apply even pressure across all capsules.
✅ Verify capsule size compatibility
Confirm the NJP800C’s tooling matches the exact capsule size and specifications, as mismatched tooling causes misclosure.
Problem 2: Powder Leakage and Cross-Contamination Risks
Symptoms
Excess powder buildup in the closing station causes friction, leading to scratched capsules and contamination between batches.
Solutions
✅ Increase post-filling cleaning frequency
Regularly clean the closing dies and surrounding area to remove powder residue that can interfere with proper closure.
✅ Adjust the vacuum powder removal system
Optimize the vacuum level to remove excess powder from the capsule rims before closing, preventing trapped particles from disrupting the seal.
