Troubleshooting Guide
| 1.POWDER APPLICATION | 2.CURED FILM DEFFECTS 3.MECHANICAL &CHEMICAL PROPERTY |
| 1.1.Thin Film (Substrates show through and coating layer has grainy flow) | |
| Possible Causes | Solutions |
| High humidity powder | Control environment Ensure all powders are kept sealed until required to use |
| Poor charging | Increase voltage Clean or replace electrodes,cables,etc if needed Decrease powder delivery rate |
| Poor grounding | Use clean hooks; Check and improve grounding |
| Poor deposition rate | Increase powder delivery air;Reduce line speed |
| Faraday cage effect | Adjust voltage and forward air flow |
| 1.2.Poor Fluidization (Poor fluidization causes slow and no transportation of powder from fluid container to guns) | |
| Possible Causes | Solutions |
| Fluidizing air too low or too high | Change air pressure; Use large hose diameter |
| Oil remnants in compressed air | Check filter in front of coating booth |
| Damp or compact powder | Manually loosen powder in hopper |
| 1.3.Poor Penetration in Faraday areas | |
| Possible Causes | Solutions |
| Voltage not optimized | Reduce voltage,so that surfaces closest to the gun do not repel powder |
| Powder delivery rate not optimized |
Adjust delivery rate |
| Poor part ground | Check and improve grounding |
| Incorrect powder spray pattern | Try different spray nozzle |
| Poor gun placement | Adjust gun position |
| Poor part presentation | Improve part presentation |
| Powder too fine | Reduce ratio of reclaim to hopper |
| 1.4.Back Ionization (Surface looks uneven and broken before curing ) | |
| Possible Causes | Solutions |
| Gun voltage too high | Reduce voltage |
| Gun too close to part | Increase the distance between gun and part |
| Poor part grounding | Check and improve the grounding |
| Excessive powder build-up | Spray thinner film |
| Moisture powder | Ensure no moisture is entering the system |
| 1.5.Powder Surging or Spitting | |
| Possible Causes | Solutions |
| Not optimized powder delivery rate |
Optimize powder delivery rate |
| Incorrect hose diameter | Uses smaller diameter hose |
| Improper air pressure | Optimize air pressure |
| Clogged worn parts,tubes or hoses | Check and clean or replace worn parts as needed |
| Moisture in compressed air | Ensure clean dry air |
| Much more fines powder | Add virgin powder |
| 1.6.Much Thicker Film(layer shows uneven surface before curing,orange peel or pinholes will show after curing | |
| Possible Causes | Solutions |
| Excessive powder delivery | Reduce powder feed to gun Increase distance between gun and component |
| Curing time too long | Shorten curing time |
| Gun voltage too high | Adjust voltage |
| Too much pre-heat(if exists) | Reduce pre-heat cycle |
| 2.CURED FILM DEFFECTS | |
| 2.1.Pinholes In the Filem(Fine pores on the surface,also can leads to change in gloss ) | |
| Possible Causes | Solutions |
| Inadequate cleaning of substrate | Check cleaning and phosphating |
| Silicone,oil Contaminatants | Check source and eliminate,check degreasing plant |
| Oil in compressed air supply | Ensure clean ,dry air supply |
| Moisture content in powder too high |
Testing through drying of powder |
| Very porous workpiece | Check for satisfactory workpieces,maybe no enough sandblasting |
| 2.2.Picture Framing(Higher film build-in on the edges of part due to wrap,uneven flow) | |
| Possible Cause | Solutions |
| Excessive film thickness | Reduce film thickness |
| Poor part grounding | Check and improve grounding |
| Voltage too high | Adjust voltage to suit |
| Feed air or powder flow too high | Adjust powder flow |
| 2.3.Outgassing or blistering | |
| Possible Cause | Solutions |
| Excessive film thickness | Check system parameter,reduce film thickness |
| Cast or other porous substrate | De-gas at or above cure temperature |
| Water on workpiece | Check dryer and hanging configuration |
| Liquid paint under powder | Remove pain,de-gas at or above cure temperature |
| 2.4.Orange Peel(Poor flow,short or long waviness of coating layer,shown after curing) | |
| Possible Causes | Solutions |
| Heat up cycle of part too slow | Increse heat up rate |
| Improper film thickness | Check system parameter and adjust film thickness |
| Incompatibility with other powder | Clean booth,check compatibility |
| Voltage too high | Optimize voltage |
| Substrate profile | Increase film thickness or change substrate |
| Powder Stored at or exposed to elevated temperature |
Replace powder Store powder at or below recommended temp. |
| Unsuitable particle zise distribution | Optimize particle size distribution |
| 2.5.Low Gloss | |
| Possible Causes | Solutions |
| Oven temperature too high | Redue temperature,and check metal temperature,or increase line speed |
| Time in oven too long | Increase line speed;decrease oven temp. |
| Contamination with a powder | Clean all equipment including gun,booth,recovery system |
| 2.6.High Gloss | |
| Undercured coating flim | Increase curing time or temperature |
| Slow heat up cycle | Increase cure temperature;preheat substrate |
| 2.7.Poor Adhesion | |
| Undercured film | Increase oven temperature;decrease line speed |
| Poor pre-treatment | Check pre-treatment |
| 2.8.Contamination of colos | |
| Possible Causes | Solutions |
| Poor cleaning when color changing |
Clean plant,gun and recycling system |
| Cross contamination at manufacturer |
Contact powder supplier |
| Contamination from equipment cleaning |
Vacuuming is more effective |
| Desposits from dust and particle in oven |
Donot cure other color at same time; reduce air speed |
| 2.9.Off-color or yellowing | |
| Possible Causes | Solutions |
| Overbaking | Reduce curing time or temperature Increse line speed Check burner locations to eliminate hot spots |
| Line stoppages | Eliminate line stoppages or reduce oven temp.during stoppages Leave gaps to provide for scheduled line stoppages |
| Inadequate oven exhaust | Increase oven exhaust rate or reduce line loading |
| 1.POWDER APPLICATION | 2.CURED FILM DEFFECTS |
