Powder Coating is a dry powder painting process. The powders are usually thermosetting plastics like epoxies, polyester, nylons, PU, acrylic or hybrids

This is for a number of reasons:
1) The coat is stronger, more resistant to chemical attacks, smoother & gives more uniform finish easily.
2) The process is simple requiring minimum operator training. Simply follow the process as laid out.
3) This process is environment friendly as those are VOCs.
4) This process overall is cost effective.

Virtually all surfaces made of conductive material like metals in general and now MDF wood with some limitations. The only practical constraint is to uniformly post-heat the article to 180 - 220°C

1) More durable and resistant to chips, scratches, and corrosion
2) Environmentally friendly (no VOCs)
3) Available in many colors, textures, and finishes
4) Cost-effective in the long run

A good quality complete powder coating set up consists of:
1) Chemical or Mechanical surface pretreatment (to clean & prepare the surface)
2) A high-quality Powder Coating Machine that can generate 100KV electrostatic voltage (controlled & variable) at the tip of the spray gun (to charge the powder particles before they are sprayed). This is the heart of the set up & will decide the final quality of the coating.
3) An enclosure in which to place the article to coat. This “Powder Booth” is linked to a powder recovery system (to collect (for reuse) oversprayed powder). The Powder recovery system will determine the economies of Powder Coating.
4) An Oven large enough to accept the coated articles to be “cured” at temperatures in the range of 180 - 220°C. Depending on production requirements, ovens designed to accept large quantities of coated article at a time
5) For high production requirements material movement is automated using overhead conveyors.

The Orange Peel effect is a powder coated surface that actually resembles an orange peel. Although this has been accepted as a consequence of electrostatics in Powder Coating, it is more obvious in glossy finishes as compared to semi-glossy or matt and structured finishes. This can be reduced to some extent by following proper curing parameters as laid down by the powder manufacturers. Incomplete curing could lead to exaggerated Orange Peel. Some causes:
1) Improper curing temperature and schedule.
2) A slow build up of temperature while curing
3) Old powder or poor-quality powder
4) The powder coating film may be too high or too low

This is an Electrostatic effect that makes it a little difficult to coat corners and deep crevices. This is mostly taken care of by ensuring proper grounding of the article and the gun and reducing the charging voltage to minimize the electrostatic effect. With modern guns, the latter is easily achieved as the control system on these guns automatically is reduced the charging voltage with the distance between the gun tip and the article.

These are small circular eruptions on the coated surface. This is usually caused by moisture or oil contamination in the compressed air. Good quality compressed air filter should take care of the problem.

A number of factors could contribute to this
1) Improper or incorrect pretreatment.
2) Improper or incomplete powder curing cycle in the oven.

Multiple causes:
1) Moisture/oil content in compressed air. Use better quality of air filtration
2) Powder stored for too long. Use fresh powder
3) Coating thickness too low – specially with textured/structured finishes. Correct coating process for correct thickness
4) In castings or porous metals, could be due to outgassing while curing. Pre-outgas before coating

This is caused by improper cleaning of the gun and hopper before changing colour. It could also be caused by using recovered powder from booth / recovery system that was not thoroughly cleaned during colour change.

This is caused when the article is not thoroughly dried before being powder coated. Check & correct your pretreatment process
1) Why am I getting a Gloss level too high?
This is usually caused by improper curing cycle in the oven. Either the curing temperature is too low or the curing time is too low or both. Take measures to rectify this.
2) What are the causes of Color Variation?
There are number of possible causes for this:
(a) The Coating thickness is uneven and low so that the substrate color impacts the outcome
(b) The coating has been overcured causing partial damage to the pigment in the powder. Remedy this by following SOP.

There could be many causes of this.
1) Low air pressure setting - Check and set the “Powder” and “Fluidizing” air pressure correctly.
2) Powder feed-pump outlet and/or gun choked - Please clean thoroughly and re-fit.
3) One of the fuses may have tripped - Reset, if tripped.
4) The Solenoid Valve may not be working - Replace if failed (the “Powder” and “Air” gauges will read ‘0’.

There are number of causes of this.
1) Powder insufficient - Add Powder in the Hopper.
2) Fluidizing insufficient - Increase “Fluidizing” pressure till powder in the Hopper appears like its “boiling”. If even at high pressure this does not happen, clean or replace the fluidizing plate which may be choked
3) Powder may be old and/or moist- Use fresh Powder.
4) “Dilution”/”Air” air pressure insufficient, Increase this air pressure
5) Powder feed pump and / or gun partially blocked. Thoroughly clean the complete system.
6) Powder may be too fine (multiple recovery cycles) and may require addition of virgin powder

Reset Fuses F1 and F2
Check mains supply to the machine

Reset fuse F1

If the kV controller is at max position and yet there is no charging, contact the gun manufacturer

The cause usually is poor earthing/grounding of the gun. Ensure that the gun and the booth and parts being coated are all very well grounded/earthed. Make sure the operator is holding the gun such that he is in contact with the earthing plates on the gun at all times.

There are a number of possible causes:
1) Improper earthing/grounding of the gun, parts and booth. Ensure high quality earthing
2) A damaged electrode/gun tip – check and replace if necessary
3) The gun has been set to a low charging voltage – increase the voltage to the max (100kV)
4) High air speed from the gun may be blowing the powder off the part. Reduce the “Dilution”/”Air” pressure
5) Maintain proper distance (150-200mm) between the gun tip and part being coated
6) The gun is not generating the required charge – contact the gun manufacturer

Causes:
1) Improper grounding/earthing – check and rectify
2) Powder build-up at the gun tip – clean gun thoroughly and replace powder if moist
3) Gun is too close to the part being coated – maintain a distance of 150-200mm

Caused by improper cleaning of the entire powder line in the gun, the booth and powder recovery system. This requires a thoroughly cleaning of all parts that come on contact with the powder.
In case of frequent color changes, it is recommended that you use a Direct Carton Feeder Powder Coating Machine, like the Red Line PC202IF

The powder may be old or moist. If it is old, please replace with fresh powder. If moist, check your compressed air line for moisture and oil contamination and take remedial action

1) If coating preheated articles (like castings), allow the parts to cool down a little more before coating or reduce the preheating temperature
2) If parts are being coated in cold condition, reduce the powder flow and/or the time spent over coating the article

Multiple causes:
1) Insufficient earthing/grounding – check and rectify
2) Improper connection between article-jig-hanger-booth. Clean these connections for proper earthing/grounding
3) Poor charging of powder particles – increase the charging voltage
4) Powder flow too low – increase the flow rate by increasing the “Powder”
5) Time spent on the job too less – lower the conveyor speed or simply spend more time on the articles
6) Suction into the recovery system is too high and is sucking away the sprayed powder – call the recovery system supplier to rectify this
7) If this is second coat, reduce the charging voltage and powder flow rate

Recycled/recovered powder has not been cleaned properly. Arrange proper sieving of recovered powder and mix with virgin powder before reuse. Switchover to Red Line PC202 powder coating machine which automatically sieves recovered powder to provide clean and dust/fiber-free powder for spraying
Clean the oven thoroughly as the dust may be coming from inside the oven while curing