Aluminum alloy spraying operation precautions

Gun Positioning

When using a spray gun, it's crucial to maintain a specific angle, tilting slightly towards the direction of the profile's contour. Ideally, the spray guns should be aligned vertically and parallel to each other in the setup, ensuring their ends form a straight line without any overlap. Additionally, the positions of the upper and lower spray guns need to be adjusted properly to cover all the profiles effectively.

Fluidized Gas Pressure Control

Controlling the fluidized gas pressure is essential for the optimal performance of the fluidized bed. Its purpose is to create a proper fluidization state by using airflow, giving the powder a liquid-like consistency when stirred. A simple way to check if the fluidization is adequate is by attempting to stir the powder with your hand or a stick; there should be no resistance. Proper fluidization helps the powder get drawn into the catheter and, under accelerated airflow, aids in atomization. Insufficient or excessive pressure can disrupt the fluidization process.

Powder Recycling

Recycling and reusing the powder is both economical and environmentally friendly. Only about one-third of the powder output from all the spray guns adheres to the profile's surface, while the rest gets scattered within the spray booth. It’s important to mix the recycled powder with new additions in the right proportion to maintain quality. Therefore, recycling the powder promptly after use is recommended to maximize efficiency and reduce waste.

Sealing in the Spray Booth

Ensuring proper sealing in the spray booth is vital to prevent contamination by airborne particles. Without adequate sealing, the profile’s surface may develop lumps or shrinkage after spraying, leading to uneven surfaces post-baking. Hence, it's necessary to implement sealing measures to keep pollutants out and maintain the integrity of the finish.

Cleaning Residual Powder

Any leftover powder in the system should be cleaned regularly to avoid clumping, especially if the equipment remains unused for extended periods. Clumped powder can cause issues like powder spitting, negatively impacting the spray results.

Spare Powder Bucket Maintenance

A spare powder bucket is useful for replacing powder efficiently, improving productivity. Proper dustproof and moisture-proof measures should be taken to preserve the quality of the remaining powder in the bucket.

Powder Filling Operation

Replenishing powder demands careful attention. While technical parameters are pre-set, continuous monitoring of the profile through the powder filling window is necessary. If the powder level is low or if the powder isn’t being adequately absorbed, adjustments should be made accordingly. Since manual guns dispense more powder than automatic ones, manual guns can be adjusted manually if needed. Some profiles have hard-to-reach areas where even adding more powder won’t yield the desired effect. Identifying these spots prevents overuse of powder, which could harm surface quality and lead to wastage.

Oven (Cure Oven) Operation

During the powder coating process, several factors need attention. Due to production line limitations, the time a profile spends in the oven determines the entire curing process. Although the oven’s operational steps are straightforward, precise control of process parameters is critical. Parameters like conveyor belt speed and furnace temperature require meticulous regulation. Conveyor belt speed can be adjusted via the variable frequency motor’s frequency. For furnace temperature control, the primary focus is adjusting the gas supply pressure, which needs to remain stable around 1 kg/cm². To meet this requirement, pipeline gas is typically used, with continuous pressure adjustments by the compressor to ensure the combustion device operates correctly.