Weld Powder Coating Machine: The "Invisible Guardian" Against Can Rust
The CTPC series weld powder coating machine is an electrostatic coating equipment launched by Chengdu Changtai Intelligent Equipment Co., Ltd., suitable for the canned food and industrial can-making industries. Adopting high-voltage electrostatic adsorption technology, it boasts advantages such as uniform coating, easy operation, and automatic powder recycling. Through precise parameter setting, standardized installation and operation, regular daily maintenance, and targeted troubleshooting, it can achieve rust and corrosion protection for the inner side of can body welds.
I. Equipment Positioning and Core Advantages
The CTPC series weld powder coating machine is a core product of Chengdu Changtai Intelligent Equipment Co., Ltd. Specifically designed for the canned food and industrial can-making industries, it focuses on rust prevention and corrosion protection against contents for the inner side of welding seams of can bodies, adapting to the internal coating protection of can bodies welded by various specifications of rear-feed welding machines. Compared with the traditional glue touch-up method, this machine adopts high-voltage electrostatic adsorption technology, boasting advantages such as uniform coating without fine pores, odorless working environment, and easy operation. Moreover, the powder can be automatically recycled—for powder of the same color, there is no need to empty the remaining powder in the bucket if it is reused within seven days, greatly reducing waste and pollution.
II. Working Principle, Core Structure and Complete Process
(I) Working Principle
The resin powder mixture sprayed by the ejector is charged after passing through the high-voltage electrostatic field formed by the high-voltage discharge needle. It is adsorbed to the inner side of the can body's weld along the direction of gas flow, so that the powder adheres firmly to the can body. Then, through heating by the supporting dryer, the powder melts and plasticizes, eventually forming a protective film on the weld.
(II) Core Structure
The equipment is composed of key components such as a vibrating screen powder separator, powder storage bucket, powder supply bucket, recovery filter, ejector, powder arm, and recovery hood. The powder arm can flexibly adjust its horizontal and vertical positions to ensure precise powder spraying; the recovery hood is divided into large and small types—the large hood is 10-15mm away from the can body, and the small hood is equipped with a brush to recover excess powder; the iron recovery and removal box has a built-in strong magnet bar, which can absorb welding iron impurities in the powder to ensure coating purity.
(III) Working Process
- 1.Powder Supply Stage: New powder enters the vibrating screen through the powder absorber and pipe clamp valve, filters out impurities, and then falls into the powder storage bucket. The hot air generated by the fluidizing fan fluidizes the powder, which then enters the powder supply bucket through air pressure balance control.
- 2.Powder Spraying Stage: The ejector generates vacuum to suck out the powder in the powder supply bucket, mixes it with compressed air to form a powder-gas mixture, and delivers it to the powder spraying groove through the powder arm. At the same time, the high-voltage electrostatic generator charges the powder.
- 3.Adsorption Stage: The charged powder is accurately adsorbed to the inner side of the can body's weld under the action of static electricity, and the large and small recovery hoods synchronously recover scattered excess powder.
- 4.Recovery and Circulation Stage: The recovered powder removes iron impurities through the iron removal box and then re-enters the powder storage bucket for recycling.
- 5.Curing Stage: The sprayed can body enters the dryer, and the powder melts and plasticizes through heating to form a protective coating.
III. Key Parameters and Installation Requirements
The performance parameters of the equipment need to be accurately matched: the power supply is 380V three-phase four-wire system, equipped with 4mm² power cables; the compressed air pressure needs to reach 0.6MPa, with a consumption of 100-200L/min, and the air source must be cooled by a special refrigerated dryer before entering the machine. During installation, emphasis should be placed on grounding: take three red copper rods with a diameter of 15-20mm and a length of 180cm, weld a nut or make an M12 screw rod at one end, and sharpen the other end. Drive them vertically into moist soil at a spacing of 200cm, then connect and fasten the three copper rods with 60mm² pure copper wires, and then connect them to the machine with 10mm² pure copper wires. For pipeline connection, it is recommended to use a 100mm diameter PVC pipe for storage to ensure a neat production line.
IV. Operation Modes and Parameter Settings
The operation is divided into automatic and manual modes, which can be easily controlled through the touch screen. In automatic mode, the front and rear delay times of powder spraying (front end 0.1-3s, rear end 3-30s) and high-voltage (38-65KV, take a larger value when the powder is moist) can be set; in manual mode, the recovery fan must be turned on first before performing operations such as powder spraying and cleaning. The air pressure and flow must strictly follow the standards: powder spraying pressure 0.18-0.2MPa, atomization pressure 0.16-0.18MPa, recovery pressure 0.3-0.4MPa, and the total flow of powder spraying + atomization + external flow resistance must be less than 18L/min.
V. Troubleshooting and Quality Inspection
Common faults can be solved targetedly: uneven powder thickness can be adjusted by changing the height of the large recovery hood or the balance ball valve of the powder supply bucket; powder falling may be due to insufficient high voltage or moist powder, so it is necessary to increase the voltage or dry the powder; poor coating adhesion requires checking the drying temperature.
Quality inspection is divided into two steps: before baking, the powder sprayed on the can body should be visually inspected after taking it out, and it should be of uniform thickness, consistent front and rear, left and right, and should not fall off when gently shaken by hand; after baking and cooling, cut an X-shape at 90 degrees in sections (front, middle, rear) of the can body with a blade, pick up the sharp corner, and the tear-off should not exceed 10mm to break—exceeding 12mm is a defective product. In addition, cut a strip of the can body with coating along the weld, then cut horizontally to the coating, fold until the iron breaks, the coating should not break, and pull the entire coating gently at 60 degrees—breaking within 12mm is good, and the worst should not exceed 20mm.
VI. Daily Maintenance and Usage Specifications
Daily maintenance must be performed regularly: clean the powder-gas separation filter element, fluidizing fan filter element, gas balance breathable plate, and iron recovery and removal box weekly; check the reliability of the ground wire monthly. During use, note that the powder spraying groove is made of non-metallic material, and the screws should be tightened gently to avoid damage; clean the remaining powder in the bucket before changing the powder or shutting down for a long time, and lock the sealing door when closing to prevent powder leakage, ensuring the long-term stable operation of the equipment and building a solid line of defense for food packaging safety.
Post time: Jan-16-2026