In the field of construction machinery, the paint coating of parts not only concerns the appearance but also plays a crucial role in their protective performance and service life. The paint coating line for construction machinery parts is a professional and efficient coating solution, which is widely applied in various production enterprises of construction machinery parts.
Pretreatment System: This is the fundamental link to ensure the adhesion of the paint. Firstly, through the degreasing process, a special degreaser is used to remove impurities such as oil stains and grease from the surface of the parts, providing a clean surface for subsequent treatment. Then, the derusting operation is carried out. Methods such as pickling and shot blasting are adopted to thoroughly remove the rust and oxide scale from the surface of the parts. After that, surface conditioning treatment is conducted to adjust the microscopic structure of the part surface and enhance the phosphating effect. Finally, phosphating is carried out to form a phosphate conversion film on the surface of the parts, significantly improving the adhesion and corrosion resistance between the paint and the part surface.
Painting System: This system is the core part of the coating line. Advanced painting equipment such as spray guns and automatic painting robots are used. The spray gun can precisely adjust the painting pressure, flow rate, and angle according to the shape and size of the parts to ensure uniform paint coverage. The automatic painting robot is suitable for parts with complex shapes and large batches. It has a high degree of flexibility and precision and can perform all-round and multi-angle painting operations according to the preset program, greatly improving the painting efficiency and quality. At the same time, the painting booth is designed to be sealed and equipped with efficient ventilation and paint mist purification devices. This not only ensures a good painting environment but also effectively treats the paint mist and waste gas generated during the painting process, meeting environmental protection requirements.
Drying System: After the painting of the parts is completed, they need to be dried to cure the paint. The drying system usually adopts heating methods such as hot air circulation and infrared radiation. In hot air circulation, the hot air is evenly blown into the drying chamber by a fan, so that the parts are heated evenly to ensure a consistent paint curing effect. Infrared radiation uses the thermal effect of infrared rays to directly heat the paint on the surface of the parts, which is fast in drying speed and energy-efficient. The temperature and time in the drying chamber can be precisely controlled according to the type and characteristics of the paint to achieve the best curing effect.
Conveying System: It is responsible for accurately and efficiently conveying the parts between various processes. Chain conveyors, belt conveyors, or overhead conveyors are used, which can adapt to different types and weights of parts. The conveying speed can be adjusted according to the production rhythm to ensure the smooth operation of the entire coating line. At the same time, the conveying system is also equipped with a precise positioning device to ensure that the parts are in the correct position during processes such as painting and drying.
Control System: It conducts intelligent management and control of the entire paint coating line. Based on advanced programmable logic controllers (PLCs) or industrial computers, by writing specific control programs, it realizes the coordinated operation of the pretreatment system, painting system, drying system, and conveying system. Operators can easily set various process parameters such as painting pressure, drying temperature and time, and conveying speed through the human-machine interface (HMI), monitor the running status of the equipment in real time, and obtain equipment fault alarm information in a timely manner, which is convenient for quick troubleshooting and maintenance.
Part Loading: Place the construction machinery parts to be coated on the tooling fixtures of the conveying system. The tooling fixtures are designed according to the shape and structure of the parts to ensure the stability and accuracy of the parts during the conveying and coating processes. The conveying system slowly sends the parts into the pretreatment area.
Pretreatment: The parts go through processes such as degreasing, derusting, surface conditioning, and phosphating in sequence. In the degreasing tank, the parts are immersed in the degreaser solution for a certain period of time, and the oil stains are fully dissolved and removed. For the derusting process, an appropriate method is selected according to the material and rust degree of the parts, such as pickling treatment in the pickling tank or shot blasting treatment by the shot blasting machine. After the surface conditioning solution makes microscopic adjustments to the surface of the parts, they enter the phosphating tank for the phosphating reaction to form a phosphating film. The parts after pretreatment have a clean surface and enhanced activity, making full preparations for the subsequent painting.
Painting: The parts after pretreatment enter the painting booth. If a spray gun is used for painting, the painter manually adjusts the parameters of the spray gun according to the specific situation of the parts to ensure that the paint evenly covers the surface of the parts. For the coating line using an automatic painting robot, the robot precisely controls the movement trajectory of the spray gun and the painting parameters according to the preset program to carry out efficient and accurate painting operations on the parts. During the painting process, the temperature, humidity, and ventilation conditions in the painting booth should be strictly controlled to ensure the painting quality of the paint.
Drying: The parts after painting immediately enter the drying chamber. Set appropriate drying temperature and time according to the curing requirements of the paint. During the drying process, the solvents in the paint gradually volatilize, and the film-forming substances such as resin crosslink and cure to form a hard and wear-resistant paint coating. The surface of the dried parts should be smooth and flat, without defects such as bubbles and runs.
Quality Inspection: The dried parts reach the quality inspection area through the conveying system. A variety of inspection methods are used, such as visually inspecting the appearance quality of the paint coating to check for problems such as color difference, missed painting, and runs; using a coating thickness gauge to measure the thickness of the paint coating to ensure that it meets the process requirements; and conducting an adhesion test to evaluate the bonding strength between the paint and the part surface. For unqualified parts, rework treatment should be carried out in a timely manner.
Part Unloading: Remove the qualified parts after quality inspection from the conveying system, completing the entire paint coating process. These parts will be transported to the assembly workshop or packaged and stored for subsequent use.
Improve Coating Quality: By precisely controlling the parameters of each process, such as the process time and reagent concentration of pretreatment, the painting pressure and flow rate, and the drying temperature and time, it is ensured that the paint coating is uniform, smooth, and has strong adhesion, effectively improving the coating quality and protective performance of the parts. Compared with manual coating, the coating line has higher consistency and stability, greatly reducing the defective product rate.
Enhance Production Efficiency: The automated conveying system and efficient painting and drying equipment enable the coating line to achieve continuous and rapid production. The application of automatic painting robots further increases the painting speed and reduces the time and labor intensity of manual operation. Compared with traditional manual coating, the production efficiency can be increased several times or even dozens of times, meeting the needs of large-scale production.
Reduce Production Costs: The coating line realizes the rational utilization of resources by optimizing the process flow and equipment configuration. For example, precise painting control reduces paint waste, and the efficient drying system reduces energy consumption. At the same time, the increase in the degree of automation reduces labor costs, and the comprehensive production cost is significantly reduced.
Environmental Protection and Energy Conservation: Equipped with advanced paint mist purification and waste gas treatment devices, it can effectively treat the pollutants generated during the painting process and reduce environmental pollution. The drying system uses energy-saving heating equipment and an intelligent temperature control system, which reduces energy consumption while ensuring the drying effect, meeting the requirements of sustainable development.
A modern construction machinery parts production enterprise for excavators has introduced an advanced paint coating line. The coating line uses automatic painting robots and an intelligent control system, which can efficiently coat various types of construction machinery parts. In actual production, the coating quality of the parts of this enterprise has been significantly improved, and the product qualification rate has increased from the original 80% to over 95%. The production efficiency has been greatly improved, and the production capacity has increased by 3 times compared with the previous level, effectively meeting the market demand for construction machinery parts. At the same time, due to the reduction in paint consumption and energy consumption, the enterprise has achieved considerable savings in production costs and obtained good economic and environmental benefits.
With the continuous development of the construction machinery industry, the requirements for the coating quality and production efficiency of parts are getting higher and higher. The paint coating line for construction machinery parts, with its advanced technology and remarkable advantages, will play an even more important role in the future production of construction machinery parts, promoting the industry to develop towards a higher quality and more efficient direction.
