GOLDEN SPOT INDUSTRY INC.

MFDC stands for Mid Frequency Direct Current, and MFDC welding refers to a type of resistance welding that utilizes a mid-frequency direct current power source. This welding process is also known as Medium Frequency Direct Current (MFDC) resistance welding or simply mid-frequency welding.

Here are the key features and aspects of MFDC welding:

1. Power Source:

   • Unlike traditional resistance welding processes that use Alternating Current (AC), MFDC welding employs a direct current (DC) power source.
   • The frequency of the current is in the mid-frequency range, typically between 400 and 4000 Hertz.

2. Transformation Process:

   • The three-phase AC input is converted to a mid-frequency output through an inverter.
   • The resulting high-frequency current is then transformed to produce a continuous DC output.

3. Continuous Heating:

   • MFDC welding provides a continuous and controlled flow of direct current to the welding operation.
   • Unlike AC welding, there are no zero crossings in the waveform, leading to uninterrupted and rapid heating.

4. Fine Control and Timing:

   • The timing in MFDC welding is measured in milliseconds (ms).
   • This precise timing allows for fine control over the welding process, contributing to better control of heat input and improved welding results.

5. Reduced Inductive Losses:

   • MFDC welding systems typically experience reduced inductive losses compared to traditional AC welding.
   • This efficiency can lead to lower power requirements and improved energy utilization.

6. Smaller Transformers:

   • MFDC transformers can be made smaller than their AC counterparts due to the higher operating frequencies.
   • The reduced size contributes to lower weight, making MFDC welding systems more suitable for automation applications.

7. Versatility:

   • MFDC welding is known for its versatility and adaptability to different materials and thicknesses.
   • The process is suitable for a wide range of applications, including spot welding, seam welding, and projection welding.

8. Automation and Robotics:

   • The precise control and efficiency of MFDC welding make it well-suited for automation and robotic welding applications.
   • The reduced weight and size of the equipment enhance its compatibility with robotic systems.

In summary, MFDC welding represents an advancement in resistance welding technology, offering improved control, efficiency, and adaptability. Its continuous DC output, precise timing, and reduced inductive losses make it a preferred choice in various industries, especially in automated manufacturing processes.

Minimizing weld splash in resistance spot welding is crucial for ensuring both the quality of the weld and the safety of the welding process. Weld splash can lead to defects, inconsistent welds, and safety hazards. Here are some strategies to help minimize weld splash in resistance spot welding:

Optimize Welding Parameters:

Adjust the welding parameters, including current, voltage, and welding time, to optimal levels for the specific materials being welded. Proper parameter settings contribute to a stable and controlled welding process, reducing the likelihood of splatter.

Maintain Proper Electrode Alignment:

Ensure that the electrodes are aligned correctly and are in good condition. Misalignment or worn-out electrodes can lead to uneven pressure on the workpieces, causing splatter.

Use the Right Electrode Material and Design:

Choose electrode materials that are suitable for the specific application. Electrode materials with good thermal conductivity and durability can contribute to a more stable welding process. Additionally, consider the design of the electrodes to ensure proper contact and pressure distribution.

Control Surface Contamination:

Clean the workpieces thoroughly before welding to minimize surface contaminants. Contaminants on the metal surfaces can contribute to spattering during the welding process.

Implement Anti-Spatter Coatings:

Apply anti-spatter coatings or release agents to the electrode surfaces. These coatings can help prevent the adhesion of molten metal to the electrodes, reducing the likelihood of splatter.

Optimize Material Thickness:

Choose appropriate material thickness for spot welding. Welding thin materials may require different parameters than thicker materials. Adjusting the welding parameters based on material thickness can help minimize splatter.

Implement Water-Cooling Systems:

Consider using water-cooled electrodes to manage heat buildup during the welding process. Controlling the temperature of the electrodes can contribute to a more stable welding environment, reducing the likelihood of splatter.

Regular Maintenance:

Perform regular maintenance on welding equipment, including cleaning and inspecting electrodes, to ensure they are in optimal condition. Replace worn-out or damaged components promptly.

Training and Skill Development:

Provide proper training for operators to ensure they have the skills and knowledge to operate the spot welding equipment effectively. Skilled operators are better equipped to control the welding process and minimize splatter.
By combining these strategies, you can improve the quality and safety of resistance spot welding while minimizing weld splash. It's essential to experiment and fine-tune the parameters based on the specific materials and conditions of your welding application.

Resistance welder is high current but with low voltage, so operator will not be electric shocked unless cable is damaged or insulation is broken.

Spot welder is based on the resistance of the two workpieces, high current through the workpiece generates heat to be melted. Most of the material is steel or stainless steel.

Resistance for Copper and Aluminum is small, not easy to generate heat to weld by AC welder.

Based on some special material will recommend capacitor discharge welder or MFDC welder.

1. Short welding time, usually 0.1sec per spot. Heat is concentrated and workpiece is less deformed.
2. No refillable consumables required, such as welding rod, oxygen, acetylene, argon…etc.
3. Simple operation, easy for beginner to get started, no need professional operator.
4. No harmful gas or and no strong light damage.
5. High production efficiency, can work with semi-automatic or fully automatic system.

Electrodes are usually made of copper alloys with high conductivity and medium hardness, and chromium copper (CuCr) or chromium zirconium copper (CuCrZr) which are widely used.

Water cooling is one of important thing for resistance welder. But if welder is low usage without installing cooling system could acceptable. Operator can check if the electrode is cooled down during the rest of spot welding. If the electrode is too hot during use, would recommend install a water cooling system.

The cooling water should be within ±3 degrees of indoor temperature, and the water quality should meet the industrial water standards. If the water quality is poor, the scale deposited will easily block the cooling water pipe, resulting in insufficient cooling. In severe cases, the welding transformer, S.C.R (thyristor) or other components will be damaged. The temperature of the outlet water must be confirmed. If the temperature is too high, the flow or temperature needs to be adjusted.

1. When the copper plate and electrode copper get hot, the current through the workpiece is not well, will cause poor spot welding performance.
2. Deterioration of copper plates and electrodes, will cause poor spot weld permanently.
3. Welding transformer, S.C.R (thyristor) or other parts will be easily damaged.

The initial color of electrode or copper plate on the machine is copper color, but the color will become dark if oxidation or there are oil stains on it. It can be cleaned by using cloth or fine sandpaper or applying metal polish wiped on surface of copper; it will looks like a new one.

*Note: Cannot wiped metal polish between two copper connect.

If the internal color still looks darker, it may because of insufficient cooling water or poor copper connect, and cause overheating and deterioration. Will recommended to check the actual problem then to improve or replace it with a new electrode (the blackened electrode has poor conductivity).

F.R.L is combined with Air Filer, Regulator and Lubricator Modular.

Air Filter: Filters remove water, dirt and other harmful debris from an air system by manually or automatically.

*The filtering is limited, air needs to be purified and dewatered in front of F.R.L (before through the F.R.L), otherwise the pressure regulator, electric value or welding cylinder will be damaged.

Regulator: Adjust and control the air pressure of the system to ensure that down-line components do not exceed their maximum operating pressures.

*Recommend setting with 2~5bar.

Lubricator: Reduce the internal friction in equipment by releasing a controlled of oil to ensure proper pneumatic component operation and increase their operation lifetime. Operator can adjust the oil drip though the visible area. Will recommend to drop once every 7 times of welding.

*Lubricating by using ISO VG32, please refuel when oil is not enough in the oil cup.