Products Description
Introduction to Robotic Arm Powder Spraying Line
In the field of modern industrial coating, the application of automated equipment has become the key to improving production efficiency and coating quality. As a professional equipment integrating mechanical automation technology and powder coating process, the robotic arm powder spraying line, with its advantages of precision, high efficiency and stability, is gradually replacing traditional manual spraying. It is widely used in automobile, hardware, household appliance and other industries, and has become one of the core equipments for industrial surface treatment.
I. Equipment Definition and Core Positioning
The robotic arm powder spraying line (Robotic Arm Powder Spraying Line) is a complete set of production line that takes the multi-axis robotic arm as the core operation unit and is equipped with powder supply, electrostatic generation, curing and drying, workpiece conveying and powder recovery systems to realize automatic powder spraying on the surface of workpieces. Its core positioning is to solve the problems of "low precision, slow efficiency, uneven coating and heavy pollution" in traditional manual spraying. It is especially suitable for the coating needs of workpieces with complex shapes, large batches and high quality requirements, and can achieve the dual coating goals of "protection" and "decoration".
II. Core System Composition (Including Technical Features)
The performance of the robotic arm powder spraying line depends on the coordinated operation of various systems. Different systems are designed according to the three needs of "precision spraying", "stable production" and "environmental protection and energy saving". The specific composition and features are as follows:
1. Multi-Axis Robotic Arm Spraying Unit (Core Executive Component)
Equipment Configuration: Usually 4-6 axis industrial robotic arms are used, equipped with electrostatic powder spray guns (single-gun or multi-gun combination), and some high-end production lines are equipped with visual positioning systems;
Technical Advantages: The positioning accuracy of the 6-axis robotic arm can reach ±0.1mm, which can flexibly adjust the spraying angle (0-360°) and distance (150-300mm) to adapt to complex workpieces (such as curved surfaces, holes and grooves of auto parts); the visual positioning system can recognize the position deviation of workpieces in real time, automatically correct the spraying path, and avoid missing spraying and re-spraying;
Operation Logic: Spraying parameters (such as spray gun flow rate, electrostatic voltage, moving speed) are preset through programming, which supports the storage of multi-variety workpiece programs. When switching products, only the corresponding program needs to be called, saving debugging time.
2. Powder Supply and Electrostatic Generation System
Powder Supply: A closed-loop powder supply barrel is adopted, and the powder is evenly delivered to the spray gun through compressed air. The powder supply amount can be accurately adjusted (50-300g/min) to avoid coating particles caused by powder agglomeration;
Electrostatic Generation: The high-voltage electrostatic generator outputs a stable voltage of 50-100kV, which makes the powder particles negatively charged. The workpiece is grounded to form an electric field, and the charged powder is quickly adsorbed on the surface of the workpiece under the action of the electric field force, improving the powder utilization rate (the basic utilization rate is more than 85%, and can exceed 95% with the recovery system).
3. Workpiece Conveying and Positioning System
Conveying Method: According to the type of workpiece, suspension chain conveying (suitable for small and medium-sized workpieces, such as hardware accessories and household appliance casings) or roller conveying (suitable for large/heavy workpieces, such as automobile chassis and engineering machinery parts) is adopted;
Positioning Design: The conveying line is equipped with a pneumatic clamping tooling, which automatically clamps and fixes the workpiece when it is in place to avoid displacement during the spraying process; some production lines adopt servo-driven conveying to realize the synchronous linkage of "spraying-conveying" and ensure uniform coating thickness.
4. Curing and Drying System
Equipment Form: Mostly tunnel-type high-temperature curing ovens, which use electric heating or natural gas heating, and realize partition temperature control in the oven (preheating zone, constant temperature zone, cooling zone);
Process Parameters: The temperature of the constant temperature zone can be set to 180-220℃ (adjusted according to the type of powder), the baking time is 15-30min, and the temperature difference is controlled within ±3℃, which ensures that the powder is fully melted, leveled and cured into a film. The coating adhesion reaches Grade 1 in the GB/T 9286-1998 standard (no peeling in the cross-cut test).
5. Powder Recovery and Environmental Protection System
Recovery Device: A combination of "cyclone separator + filter cartridge dust collector" is adopted. The unadsorbed powder is first initially recovered by the cyclone separator (recovery rate is about 80%), and the fine powder is then filtered through the filter cartridge (filtration accuracy is more than 0.3μm);
Environmental Protection Design: An activated carbon adsorption device is equipped to treat volatile gases, and the exhaust gas meets the "Comprehensive Emission Standard of Atmospheric Pollutants" (GB 16297-1996); the recovered powder can be reused after screening, reducing raw material waste and solid waste discharge.
III. Working Process (Taking Auto Parts Spraying as an Example)
The working process of the robotic arm powder spraying line follows the closed-loop logic of "pretreatment → loading → spraying → curing → cooling → unloading → inspection", and all links are closely connected. The specific steps are as follows:
Workpiece Pretreatment: The workpiece is first degreased, pickled and phosphated (or silane treated) to remove oil stains and rust on the surface and form a clean base (the quality of pretreatment directly affects the coating adhesion and is a key pre-link);
Loading and Positioning: Workers hang the pretreated workpieces on the conveying line tooling, the tooling automatically clamps, and the conveying line sends the workpieces to the entrance of the spraying room;
Automatic Spraying: After the workpiece enters the spraying room, the visual system identifies the workpiece model, calls the preset program, the multi-axis robotic arm drives the spray gun to move according to the path, and at the same time, the electrostatic generator is activated, and the powder is evenly adsorbed on the surface of the workpiece after being charged;
Curing and Film Formation: The sprayed workpiece is sent to the curing oven, first passes through the preheating zone (120-150℃) to remove moisture, then enters the constant temperature zone (200℃) for baking for 20min, and finally cools down in the cooling zone (≤60℃);
Inspection and Unloading: After cooling, the workpiece is unloaded. Quality inspectors conduct quality testing on the coating thickness, adhesion and appearance with a coating thickness gauge, adhesion tester and color difference meter. Qualified workpieces enter the next process, and unqualified workpieces are marked for rework.
IV. Outstanding Advantages (Compared with Traditional Manual Spraying)
More Stable Coating Quality: The spraying parameters of the robotic arm are accurately controllable, the coating thickness deviation is ≤±5μm, and the color difference ΔE ≤1.0 (CIE LAB standard), which avoids the problems of "uneven thickness, missing spraying and sagging" in manual spraying, and the qualified rate is increased from 85% (manual) to more than 98%;
Higher Production Efficiency: A single production line can realize 24-hour continuous production, and the spraying rhythm is adjusted according to the size of the workpiece (for example, 500-800 small hardware parts can be sprayed per hour, and 30-50 auto wheels can be sprayed per hour), which is 3-5 times more efficient than manual spraying;
More Controllable Cost: On the one hand, the powder recovery rate is high (more than 95%), reducing raw material waste; on the other hand, a single production line only needs 1-2 people for monitoring and operation, saving labor costs (traditional manual spraying requires 3-5 people per line), and the long-term use economy is significant;
Better Compliance with Environmental Protection Requirements: There is no solvent volatilization throughout the process (different from solvent-based coatings), and the powder recovery system reduces dust emissions, which meets the requirements of "green production" in modern industry and reduces the risk of enterprise environmental compliance.
V. Application Fields and Typical Applications
Due to its strong adaptability, the robotic arm powder spraying line has been widely used in the coating of metal workpieces in many industries. Typical scenarios include:
Automobile Industry: Auto wheels, brake calipers, engine brackets, body frames, etc., which require the coating to be salt spray resistant (≥500 hours) and impact resistant (≥50kg・cm);
Hardware Industry: Anti-theft doors, guardrails, tool boxes, bearings, etc., which require the coating to be wear resistant (≥300 revolutions without exposing the base, in line with GB/T 1768-2021) and uniform in color;
Household Appliance Industry: Refrigerator casings, washing machine inner drums, air conditioner outdoor units, etc., which require the coating to be temperature resistant (-30℃ to 80℃ without cracking) and scratch resistant (hardness ≥2H, pencil hardness test);
Engineering Machinery Industry: Excavator arms, loader cabs, crane booms, etc., which require the coating to be weather resistant (no obvious fading after 5 years of outdoor exposure) and corrosion resistant.
VI. Equipment Selection and Maintenance Suggestions
1. Key Indicators for Selection
According to Workpiece Size: For small workpieces (≤300mm), select 4-axis robotic arm + suspension chain conveying; for large workpieces (≥1000mm), select 6-axis robotic arm + roller conveying;
According to Production Capacity Requirements: For a daily output of ≤5000 pieces, select a single robotic arm production line; for a daily output of ≥10000 pieces, select a double robotic arm or multi-robotic arm parallel production line;
According to Environmental Protection Requirements: If the local environmental protection standards are strict, priority should be given to the recovery system equipped with HEPA high-efficiency filter and activated carbon adsorption.
2. Daily Maintenance Points
Daily: Clean the spray gun nozzle (to avoid powder blockage), check the powder remaining in the powder supply barrel, and clean the impurities in the conveying line tooling;
Weekly: Check the lubricating oil level of the robotic arm, test the voltage stability of the electrostatic generator, and clean the powder in the filter cartridge dust collector;
Monthly: Calibrate the temperature sensor of the curing oven, check the tension of the suspension chain, and test the accuracy of the visual positioning system.
