The Ultimate Buyer's Guide for Purchasing Automatic powder coating line

05 May.,2025

 

Powder Coating Line - Tifuls Coating System Manufacturer

Workpiece Not Attracting Powder 1. The electrostatic spray gun has no voltage or low voltage. 1. Check the wiring and voltage of the spray gun. 2. Poor contact of the workpiece or thick insulation layer on the hanger. 2. Check the contact and grounding of the workpiece, remove the insulation layer of the hanger. 3. Excessive exhaust air volume in the spray booth. 3. Reduce the exhaust air volume. 4. Unreasonable hanger design causing shielding effect. 4. Adjust the hanger. 5. The distance between the workpiece and the spray gun is too far. 5. Adjust the distance between the spray gun and the workpiece. Insufficient Powder Coating on Workpiece 1. Insufficient powder output from the spray gun. 1. Adjust the powder output from the spray gun. 2. Blockage in the powder supply system or pipeline. 2. Unblock the powder supply system or replace the powder supply pipe. 3. Insufficient electrostatic high voltage or poor charging of the friction spray gun. 3. Increase the electrostatic high voltage or check the charging effect of the friction spray gun and powder. 4. Thick cured powder layer on the hanger, causing high resistance. 4. Remove the cured coating on the hanger to reduce resistance. 5. Insufficient powder spraying time. 5. Adjust and extend the powder spraying time. 6. Unreasonable arrangement of the workpiece and spray gun. 6. Adjust the arrangement of the workpiece and spray gun. Excessive Powder Coating on Workpiece 1. Excessive powder output from the spray gun. 1. Adjust the powder output from the spray gun. 2. Electrostatic voltage too high. 2. Adjust the electrostatic voltage. 3. Conveyor speed too slow. 3. Adjust the conveyor speed. 4. Spray gun too close to the workpiece. 4. Adjust the distance between the spray gun and the workpiece. 5. Too many spray guns. 5. Adjust the number of spray guns. Powder Coating Clumping 1. Poor storage stability of powder, or pressure during transportation or storage, and unreasonable powder formula design. 1. When designing the powder formula, select resins and powders with a glass transition temperature that meets the storage stability requirements. 2. Improper storage of powders, with storage temperature higher than the required temperature. 2. Ensure the storage temperature for powders meets the temperature requirements for the specific type of powder. 3. Powder absorbs moisture or is packaged when the temperature is too high. 3. Maintain the required temperature and humidity during powder production. When the powder temperature is high, it must be cooled to a non-caking temperature (varies by type) before packaging. For already caked powder, use mechanical methods to crush and sieve them before use. 4. Excessive content of ultrafine powder coating. 4. Reduce the content of ultrafine powder during the production of powders. Uneven Powder Spray from Gun 1. Uneven powder supply from the powder system. 1. Check the powder supply device for stable powder supply pressure. 2. Accumulation of powder in the powder supply pipeline or spray gun nozzle, causing blockage. 2. Clean the powder supply pipeline and spray gun nozzle regularly to prevent powder adhesion and accumulation. 3. Powder absorbs moisture or cakes. 3. Prevent powder from absorbing moisture, shorten the contact time of recycled powder with air, and limit the proportion of recycled powder added to new powder. 4. Unstable compressed air pressure. 4. Check the stability of the air compressor pressure and the condition of the oil-water separator, ensuring that the compressed air is dry and oil-free. Poor Coating Adhesion Efficiency 1. Voltage of the high-voltage electrostatic generator is too low, resulting in poor electrostatic effect. 1. Increase the voltage of the high-voltage electrostatic generator, and check the grounding of the workpiece and the resistance of the hanger. 2. Poor charging performance of the powder when using a friction spray gun. 2. Check if the amount and type of charging additives in the powder are appropriate. 3. Excessive use of recycled powder. 3. Reduce the amount of recycled powder used. 4. Too much ultrafine powder or excessive exhaust air volume in the spray booth. 4. Decrease the content of ultrafine powder and reduce the exhaust air volume in the spray booth. 5. Powder particles are too coarse or density is too high. 5. Adjust the filler content in the powder formula and the particle size distribution during production. Honeycomb Pattern on Powder Layer 1. Excessive thickness of the electrostatic powder coating layer, causing ion repulsion. 1. Reduce the thickness of the electrostatic powder coating layer or use an electrostatic friction spray gun. 2. Spray gun too close to the workpiece. 2. Increase the distance between the spray gun and the workpiece, generally keeping them more than 150mm apart. Incorrect Powder Color, Yellowing 1. Poor heat resistance of the powder. 1. Use powders with better heat resistance or adjust the formulation to use heat-resistant pigments and additives. 2. Excessive curing temperature. 2. Lower the curing temperature. 3. Conveyor speed too slow, resulting in prolonged curing time. 3. Increase the conveyor speed. Poor Impact Strength of Powder 1. Curing temperature does not meet the process requirements. 1. Check if the curing oven temperature meets the process requirements. 2. Curing time does not meet the coating process requirements. 2. Check if the dwell time of the coated workpiece in the curing oven is sufficient, especially when the thickness of the workpiece changes or the number of workpieces increases, the baking time should be extended. 3. Powder quality does not meet the requirements, or the storage period of the powder has expired. 3. When designing the powder formula, fully consider the requirements for coating impact strength; check if the powder has exceeded its storage period. 4. Poor surface treatment of the workpiece. 4. Check the pre-treatment process and ensure proper pre-treatment. Coating with Pinholes, Bumps, or Particles 1. Poor pre-treatment of the workpiece, with stains or particles. 1. Ensure the quality of the pre-treatment process, making the surface of the workpiece free of stains and impurities. 2. Poor purification of compressed air, containing water or oil. 2. Purify the compressed air of the air compressor. 3. Coating is too thick, causing ion repulsion. 3. Control the coating thickness to be below 150 microns during cold spraying. 4. Powder with blocked curing agents or those that release small molecules during curing is applied too thickly. 4. For powder with blocked curing agents and those releasing small molecules, control the coating thickness to be below 100 microns. 5. Pinholes on the surface of cast iron, cast aluminum, hot-rolled steel plate, and galvanized sheet. 5. For workpieces with sand holes or pinholes, hot spraying is better; if cold spraying is required, add suitable defoamers in the formula. 6. Interference between powders of different types or manufacturers. 6. Clean the powder spraying system thoroughly to prevent interference between different types of powder. 7. Unclean spraying environment with dust and contaminants. 7. Keep the environment around the powder spraying booth clean to prevent contamination. 8. Unclean curing environment for the coating. 8. Maintain a clean curing environment. 9. Impurities falling from hangers contaminating the workpiece. 9. Regularly clean impurities and contaminants from hangers to prevent them from falling. 10. Coating thickness is too thin, resulting in poor leveling. 10. Ensure the coating thickness meets the requirements to avoid being too thin. 11. Raw materials contain non-melting or non-dispersing substances, introducing impurities during powder production. 11. Control the quality of raw materials and maintain a clean environment during production to prevent impurities from entering the product. 12. Extruder not cleaned properly or extrusion temperature too high, causing partial gelling of powder coating particles. 12. Clean the extruder thoroughly and avoid excessively high extrusion temperatures. Coating Sagging 1. Low melt viscosity of the powder coating. 1. Choose resins with high melt viscosity. 2. Excessive coating thickness. 2. Avoid excessive coating thickness. 3. Long gelation time of the powder coating. 3. Adjust the gelation time of the powder coating, adding accelerators to shorten it if necessary. Loss of Gloss, Discoloration 1. Incomplete cleaning of the powder supply and spraying system, leading to contamination with different types or colors of powder. 1. Thoroughly clean the entire system and spray booth when changing powder types and colors. 2. Excessive curing temperature. 2. Control the curing temperature within the process requirements. 3. Curing time too long. 3. Adjust the curing time according to process requirements. 4. Quality issues with the powder material. 4. Use higher quality powder materials. Poor Coating Adhesion 1. Poor pre-treatment of the workpiece, such as inadequate oil removal, rust removal, or phosphating. 1. Strictly perform pre-treatment on the workpiece. 2. Curing temperature of the workpiece does not meet the process requirements. 2. Bake and cure strictly according to the process temperature requirements. 3. Curing time of the workpiece does not meet the process requirements. 3. Bake and cure strictly according to the process time requirements. 4. Powder quality does not meet the requirements or has exceeded its storage period. 4. Adjust the powder formula to improve coating adhesion; do not use coatings that have exceeded their storage period unless they are re-tested and found to be qualified or modified to meet standards. 5. Thermoplastic powder coating was applied without a primer. 5. Apply a primer when high adhesion is required for thermoplastic powder coatings. 6. Coating thickness is too thick. 6. Adjust to the appropriate coating thickness. Poor Resistance to Acid, Alkali, Salt, and Water 1. Poor pre-treatment of the workpiece. 1. Strictly control the quality of pre-treatment. 2. Pinholes or uneven thickness in the coating. 2. Improve powder coating quality to ensure necessary coating thickness and uniformity. 3. Curing temperature did not meet process requirements. 3. Adhere to the specified baking temperature for curing. 4. Curing time did not meet process requirements. 4. Follow the process requirements for curing time.

A Beginner's Guide To Powder Coating Equipment Systems | Tutorial

If the product you want to powder coat has a lot of debris (rust, laser scale, preexisting paint), then you will likely need a Blast Room. A blast room is an enclosure where you use compressed air to propel abrasive material against the surface of your parts. Depending on the situation, you would typically use either an appropriate blast media (grit) or steel shot to blast all the unwanted debris off your part until it has a clean metal surface that’s ready for powder coating. Blast rooms are especially useful for job shops that work with raw materials that aren’t pristine, such as plate steel or tube stock that has areas of oxidation or welding residue. (For more information on getting the right blast room, go here.)

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If oils, solvents or chemical residue covers any part of your products’ surface, you’ll want to consider a Wash Station. A wash station is where you spray your parts with a detergent and/or chemical pretreatment agent, such as iron phosphate. Using hot water or steam to clean and then chemically prep parts is quite common. A wash station helps you increase powder adhesion and improve finish quality, even if the parts have already been blasted. Some wash stations require you to apply the chemistry manually using a spray wand. Other washers are automated and the parts travel through the cleaning, rinsing and prep stages on a conveyor.

In some operations, pretreatment requires the use of a Dry-Off Oven. This is commonly an appliance similar to a curing oven, but where the just-washed parts are heated in order to evaporate any water or chemistry still on them. This step can also help parts reach an optimum temperature for powder application.

Pretreatment equipment is incredibly useful for your operation and can make a big difference in the quality of your work, but an elaborate system isn’t always required for powder coating. While we can’t stress how important it is to have a clean surface before you apply powder, expensive pretreatment equipment isn’t mandatory for entry level coating operations where hands-on cleaning (such as with a tack rag and solvent) can be employed as needed.

Application: Powder Guns and Powder Spray Booths

Powder coating application is almost always done with a special Powder Spray Gun. In order for powder coating to work effectively, the powder must be electrostatically charged. The only way to apply this charge is with a spray gun designed exclusively for powder coating. Compressed air moves powder through the gun from a hopper or directly from the box the powder is stored in. The compressed air blows powder out of the gun as a tightly formed cloud. As the powder leaves the gun, it receives an electrostatic charge. Once charged, the powder cloud envelopes the part and the powder sticks to the surface of the grounded part (which is one of the reasons why powder coating equipment is so easy for new operators to use).

If you want to powder coat, you need a powder coating gun. There are many types of powder spray guns available on the market. We always recommend investing in a professional-grade powder gun, as they are more reliable and provide better results.

Once you have your powder gun, you’ll need to have a place to use it. Whenever you spray powder, some of the powder will end up on the floor and in the air instead of on your products. This leftover powder is referred to as overspray. Keeping this overspray out of your workspace is one of the functions of the Powder Spray Booth.

The powder spray booth is designed to keep the rest of your shop clean while providing a well-lit area for you to apply powder coating. All powder spray booths will have one or more exhaust fans. The exhaust will use filters to capture at least some of the overspray. If the exhaust works properly and the filters are maintained, the airflow in the booth should keep the overspray inside the enclosure and enable the painter to see what he’s doing. If your shop environment includes welding or blasting areas, filtered doors on the spray booth can keep airborne contaminants out of your powder coated finish.

Numerous booth configurations are available, and getting the ideal booth depends largely on what you’re coating, your floor space availability, and your workflow requirements. Powder spray booths can be open-faced or have doors on one end. They can also be tunnel style enclosures with the filtration built into the floor or wall(s). If you have space constraints, a Powder Spray Wall may help you get the airflow and filtration you need. A spray wall is just a large filtration system—essentially a spray booth without walls or a roof.

If you want to recycle your powder, you need to make sure your powder spray booth is built with a reclamation system. Usually this system will rely on pleated cartridge filters. These help you recover some of the overspray and reuse it. This can be very cost-effective if you are planning to use only one color and type of powder for your coating. The spent powder is trapped in the filters and then dislodged into a recovery bin for reuse. In more advanced systems, the powder is automatically reconditioned, mixed with virgin powder, and then returned to the supply hopper feeding the powder gun(s). If you are planning to reclaim a variety of colors, a set of removable filter modules is required. Unfortunately, the cost of buying multiple reclaim modules can add up quickly because you can only reclaim one color in each filter module.

No matter what type of booth you decide on, you’ll need a powder spray booth if you want to get quality results and maintain reasonable throughput from your coating operation. (For more information on what size powder spray booth you might need, click here.)

If you have stringent finish requirements, you may also need a Clean Room (also called an Environmental Room). This is usually a climate-controlled room built around the powder application area. The purpose of a clean room is to eliminate airborne contaminants and control the temperature and humidity during powder application to prevent any sort of contamination, clumping or consistency issues when applying the powder. Clean rooms are often recommended if your shop environment is particularly dirty or your products require an exact specification for adhesion or salt spray tolerance. (For more about requirements, click here.)

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Curing: Powder Curing Ovens

After your product is powder coated, the final step is to place it inside a specially designed Powder Curing Oven. They usually operate between 325° and 450° Fahrenheit. Once the oven is up to temperature, the temperature stabilizes. The coated products are exposed to precisely heated air for a set period of time. Once the curing process is complete, the parts are removed and allowed to cool before being handled.

Some ovens use infrared emitters to heat the surface of the coated parts, but these types of electric powered or gas catalytic ovens can be costly to buy and expensive to maintain. More commonly, ovens rely on electric heating elements or a natural gas or LP-fueled heat system. These more conventional ovens typically rely on heated air moving over the parts for convection curing.

The time it takes to cure the powder varies greatly depending on the size, shape and thickness of the parts being coated. A small, light-gauge bracket can take as little as ten minutes to cure completely, while a 20’ section of heavy-walled pipe may take over an hour to cure properly.

If you want to powder coat at a professional level, the type of oven you choose is critical.  Not only are brand-name powder curing ovens designed specifically to generate premium coating results, they are also highly efficient appliances in terms of fuel usage and energy costs. It’s likely that you’ll be using your oven several hours per week, so the cost of an inefficient design can quickly sap your profits.

Similar to powder spray booths, powder curing ovens come in multiple sizes and configurations. (For more information on what size powder coating oven you will need, click here.)

Professional Powder Coating Systems Layouts

There are two basic configurations for any powder coating line: batch or automated.

A Batch Powder Coating Line is usually a system where the parts are prepared, coated and cured in batches of multiple parts, with operators handling up to dozens or hundreds of parts at a time. The products are usually hung on metal rolling racks, which move with the parts throughout the coating process. (Remember: high-temperature or metal casters for your racks are very important!) With a batch line, parts are usually moved from stage to stage manually, and the term “batch coating system” is also commonly used to describe operations where large objects are coated individually after being moved by hand or with machine.

An Automated Powder Coating Line uses basically the same appliances as a batch system, but connects many or all of the stages via a motorized conveyor that moves the parts through at a constant rate. The products are usually loaded onto the conveyor at a set location and move through each stage, where either manual operators or automated devices clean and prep the parts and apply powder to them. Once coated, the parts move through the curing oven and then cool as they travel along the conveyor to a point where they can be unloaded.

(For more information on whether a batch coating line or an automated coating line is right for your business, follow this link to learn more about the advantages and disadvantages of each system.)

Powder Coating Equipment From Reliant Finishing Systems

Hopefully this Beginner’s Guide to Powder Coating Equipment has answered your basic questions about what powder coating is, how it is done, and what you need to start your first powder coating line. If you would like to learn more, please give us a call at (888) 770-. Reliant Finishing Systems’ specialists can help! We’ll guide you through the process of setting up a powder coating shop or adding coating capabilities to your existing fab shop or manufacturing facility. Whether it’s your very first powder coating system or you’re upgrading to a complete automated line, you can trust Reliant to provide you with sound advice and affordable, high quality equipment.

Updated Content Dec 9,

Contact us to discuss your requirements of Automatic powder coating line. Our experienced sales team can help you identify the options that best suit your needs.