Coating production lineThe process flow is divided into pre-treatment, powder coating, and heating curing.

Pre production

There are manual and automatic pre-treatment processes before processing, with the latter being divided into two types: automatic spraying and automatic immersion spraying. The workpiece must undergo surface treatment to remove oil and rust before powder coating. There are many chemicals used in this section, mainly including rust remover, oil remover, surface conditioner, phosphating agent, etc.

existCoating production lineThe first thing to pay attention to in the pre-treatment section or workshop is to establish necessary regulations for the purchase, transportation, storage, and use of strong acids and alkalis, provide workers with necessary protective clothing, safe and reliable packaging, handling, and equipment, and develop emergency response measures and rescue methods in case of accidents. Secondly, in the pre-treatment section of the painting production line, due to the presence of a certain amount of waste gas, waste liquid, and other three waste substances, it is necessary to install exhaust, liquid discharge, and three waste treatment devices in terms of environmental protection measures.

The quality of pre treated workpieces may vary due to differences in the pre-treatment liquid and coating production line processes. For well processed workpieces, the surface oil and rust should be completely removed. In order to prevent rusting again in a short period of time, phosphating or passivation treatment should be carried out in several processes after pre-treatment. Before powder coating, the phosphated workpiece should also be dried to remove its surface moisture. Small batch single piece production generally adopts natural air drying, sun drying, and air drying. For large-scale assembly line operations, low-temperature drying is generally adopted, using ovens or drying channels.

organizing production

For small batches of workpieces, manual powder spraying devices are generally used, while for large batches of workpieces, manual or automatic powder spraying devices are generally used. Whether it is manual or automatic powder spraying, it is very important to control the quality. To ensure even powder coating and consistent thickness of the sprayed workpiece, and prevent defects such as thin spraying, missed spraying, and wiping off.

In the painting production line, attention should also be paid to the hook part of the workpiece. Before entering the curing process, the powder attached to it should be blown off as much as possible to prevent the excess powder on the hook from curing. If it is difficult to remove the excess powder before curing, the cured powder film on the hook should be peeled off in a timely manner to ensure good conductivity of the hook and facilitate the powder coating of the next batch of workpieces.

Curing process

The precautions to be taken in this process include: for workpieces that have been sprayed, if they are produced in small batches, be careful to prevent powder from falling off before entering the curing furnace. If there is any powder scraping phenomenon, powder should be sprayed in a timely manner. Strictly control the process, temperature, and time during baking, and pay attention to preventing color difference, over baking, or insufficient curing caused by too short a time.

For workpieces that are automatically transported in large quantities, it is also necessary to carefully check for any missed spraying, thinning, or localized powder wiping before entering the drying oven. If any non-conforming parts are found, they should be carefully inspected to prevent them from entering the drying oven and removed for re spraying as much as possible. If individual workpieces are not qualified due to thin spraying, they can be re sprayed and re cured after curing in the drying oven.