Laser welding uses high-energy laser pulses to locally heat the material in a small area. The energy of the laser radiation diffuses into the interior of the material through heat conduction,  and the material is melted to form a specific molten pool for welding purposes. We use this technology to weld solar collector core runners to highly selective endothermic coatings.

Advantages of the laser welding process

1. In the field of solar collector plate welding,  laser welding can not only achieve copper + copper welding, but also achieve copper + aluminum welding technology, which can reduce the cost reasonably;

Second,  the laser welding is carried out on the back side, and the high temperature instantly melts and bonds the two materials together, so that the finished product has a smoother and more beautiful effect.

Third, laser welding makes the joint strength between the flow channel and the heat absorbing coating higher, and can transfer more heat quickly, thus making the solar collector have higher heat absorption efficiency.

Laser welding and ultrasonic welding

Laser welding has no damage to the coating layer of the collector plate, the traces are small, and the product is more beautiful.

Ultrasonic welding will form an indentation of 3-10 mm wide on the back of the collector plate, and the coating will be destroyed, which will affect the efficiency of the collector. According to the calculation of the total area of ​​2 square meters of copper pipes and 2 square meters, the plate loss area of ​​the whole plate is 3%-8% (0.048-0.16 square meters).

Laser welding: The material absorbs laser radiation instantaneously, the metal melts and forms a metallurgical connection, and the pulse laser has a short action time, resulting in less brittle metal phase of CuAl2 and high solder joint strength. Ultrasonic welding: solid phase connection, inconsistent deformation of copper and aluminum is prone to cracks and inclusions. The oxide layer has a great influence on the welding effect; the aluminum plate is prone to work hardening and brittleness, and the plate with higher hardness even produces resonance shattering plate.

Laser welding: Hanzhao laser JR3012SA collector plate welding system has high degree of automation, can accurately control the welding process, welding without noise, high welding efficiency, welding speed up to 120mm / S, the whole board welding time 3-5 minutes. Ultrasonic welding: usually a single welding, the noise is large during the welding process, and the production efficiency is not high.

Summary: Through the comparison of the two welding methods, it can be seen that the advantages of laser welding technology are obvious. Laser welding is the trend of the current collector welding process of flat solar water heaters, which will surely get more application and promotion.

Model features
• Appearance is steady, atmospheric; 
• Heavy-duty mechanism design, integrated casting structure. Stable and reliable, the whole machine reaches 4.5 tons; 
• Automatically correct the welding head when it is small deformation, automatically follow when the deformation is large, the welding head can be rotated by 90°, and the copper tubes arranged horizontally and vertically can be easily welded;
• Modular frame, which can be combined according to customer's requirements. The ultra-long heat collecting plate can be welded only by simple upgrade, and it is also easy to disassemble and transport;
• The sliding table transposition mechanism adopts the latest product of Dazu Precision Electromechanical - linear induction motor, linear drag, no need for transmission, fast response (refueling within a few seconds);
• The control system adopts the advanced CNC system PA8000 imported from Germany, which is a complete industrial standard;
• The welding machine uses a real-time power feedback system to accurately track real-time power dynamics with high single-point energy stability (±3%).

Basic parameters:
• The maximum size of the workbench is 10600×2300×1700mm (separable)
• Control system Germany PA8000 CNC system
• Gantry drive stage guidance Servo motor + ball screw + linear guide (both imported)
• Working slide drive Dazu linear induction motor
• Single weldable maximum product size (standard) 3000×1200mm
• Laser host model WF300A
• Maximum laser output power (W) 300W
• Maximum laser pulse energy (J) 30J/5ms
• Maximum laser peak power 6Kw
• Pulse width (ms) 0.1 ms to 50 ms
• Laser frequency (Hz) 1Hz ~ 200 Hz
• Fiber Specifications FSI-600-15
• Control System Real-Time Power Feedback System
• Cooling method Water-cooled, integrated 3HP chiller (standard)
• System power requirements 380V ± 5%, 50Hz / 40A