Applications of Robotic Welding

Traditional welding methods are very labour-intensive and have tended to slow down production processes previously. The introduction of welding industrial robots in 1960 and their subsequent development has revolutionised manufacturing and has delivered significant improvements in productivity and worker safety.

Robotic welding is now increasingly common in many types of industry and for both small and large companies. However, it is not the most suitable method for every task, and sometimes manual methods are still the best.

Different Types of Welding Robots and How They Are Used

A welding robot is a type of industrial robot that is specifically designed and programmed to weld two or more metal pieces together. Each robot is fitted with a welding system and has arms that can move in different directions using articulated joints. They can be fully automatic, where components are generally fed through on a conveyor for welding or may be semi-automatic, where an operator loads and clamps the components in position and then replaces them after welding.

Various types of robots are available, and their features make them suited to particular applications and industries:

• Cartesian robots have a box structure with a three-axis linear motion system. They have an extended reach and so generally work on extra-large and heavy components.
• Articulated robots have interconnected joints that give great flexibility and a range of motions. They can handle difficult welding techniques and are the most common type of welding robot.
• Collaborative robots are designed to work with humans and have collision detection and advanced force sensors to protect their operators. They are easier to program than other types and are more suitable for smaller companies with limited resources.
• SCARA (Selective Compliance Assembly Robot Arm) devices are generally used in high-volume, repetitive production and have a rigid vertical and horizontal arm.
• Mobile robots can move around and so can work around large pieces and reach them from difficult angles.
• Delta robots have three arms and tend to be used for spot welding or the welding of small components where speed and accuracy are important.

The various robot types can be fitted with different welding processes that can determine how they are used:

• Resistance spot welding is widely used in the automotive industry to join two or more metal sheets. The process uses articulating robots that have rotary joints with two to ten axes and a servo motor that accurately controls the movement of the spot-welding gun.
• Robotic gas metal arc welding (GMAW, otherwise known as metal inert gas or MIG) is used for metals with high melting points of conductivity where high deposition rates are necessary to achieve fast production throughput. A consumable electrode is melted to provide a filler material.
• Robotic gas tungsten arc welding (GTAW, or tungsten inert gas — TIG) is used to weld thin components where welds need to be precise and of good appearance. Variables are automatically controlled, and intelligent systems are available that have cameras to establish the weld path and assist error detection.
• Shielded metal arc welding (SMAW) robots create an arc that is between the welded material and a consumable flux electrode.
• Laser welding is typically used in the aerospace industry or to create medical devices. It is usually used to weld materials of varying thicknesses and from different angles and directions using a tracking system and a fibre laser head with a focused laser beam as the energy source.
• Plasma welding creates precise welds of metals with varying thicknesses and has short cycle times. It uses a plasma arc as the heat source, and the heated plasma flows quickly from the torch, melting the junction of metals that are to be welded.

Industries and Applications that Use Robotic Welding

Robotic welding has expanded greatly over the years and is now used in many industries that include:

• Automotive, where it was introduced back in 1960 with the introduction of the very first industrial robot. It is now commonly used on production lines where joint, spot and other welding types are employed to weld large metal sheets for car frames, bodies and various components.
• Aerospace, where safety and reliability of components are of the highest priority. The process is used to weld large-sized metal sheets and frames in the manufacturing of aircraft frames and bodies, plus components such as landing gear, fuselage sections, engine mounts and wings.
• Heavy machinery construction, where the work can range from building extremely large structures to smaller components that are used in them. Robotic welding is sufficiently versatile to handle all the different sizes as well as varying material thicknesses and shapes.
• Shipbuilding to create frames, decks and other structures for ships and submarines that require great structural integrity.
• Electronics for the precise welding of extremely small components.
• Consumer goods that demand high production standards.
• Rail industry to construct durable vehicles and rail tracks that can support high speeds and heavy weights.
• Energy sector for solar panels and wind turbine manufacturing that needs to be of consistent high quality.
• Furniture that may be composed of metal and other materials that need to be strong and sustainable, also doors and windows for the construction industry.

Many other industries use robotic welding due to its versatility and ability to produce high-quality welds quickly and consistently.

The Benefits and Drawbacks of Robotic Welding

Robotic welding is increasingly common across many industries because it offers several advantages over manual methods:

• Robots work without breaks and are capable of producing the same high-quality welds repeatedly for long periods. They are therefore ideal for mass production where consistent output is essential, and they produce better results than manual welders and at a faster pace, thus boosting productivity.
• Robots can be programmed for a variety of different tasks with various materials of different thicknesses and angles, which can be difficult to weld normally. This means they are extremely versatile and so are suitable for numerous applications and industries.
• Since they follow their programming precisely, robots move the heat source, weld pool and fuse point very accurately. As a result, weld seams are much stronger and very consistent, with a good aesthetic appearance.
• Quality is consistently high, and there are none of the defects associated with human error. This means the reject rate is extremely low, so there is very little wastage. The same applies to filler, which is used economically so that usage is less than for a manual welding operation without detracting from the strength of the weld.
• Due to the higher productivity and minimal wastage, unit costs of production will be much lower, so that profitability is increased

Although robotic welding has many advantages over traditional manual methods, it is not suitable for all industries and applications. There are two major drawbacks:

• Robotic welding systems are very expensive to buy and so you need to be able to justify the investment. Used properly, you will normally be able to recoup your investment through cost savings in between one and three years, although this will depend on the type of application. The use of robots can most often be justified for high-volume production that requires very accurate and fast throughput. Small and one-off jobs, especially those that require human intervention, are best left to traditional methods.
• Industrial robots are complex pieces of equipment and need to be specifically programmed for each task they undertake. This is not something that can be achieved by a traditional welder, and so extensive training is needed, or you have to hire someone with the necessary skills.

Is Robotic Welding for Me?

If you have a business that produces components in large volumes and each one requires the same, high-quality weld quickly, then robotic welding may be exactly the process you need. If, however, you process many different types of materials in small quantities and each one requires different kinds of work, then robotic welding will not be the ideal choice, and a human welder will be better.

Robotic welding is, at present, not really suitable for smaller companies with individual forms of work. The cost and the set-up required will mean benefits are not sufficiently obtained to justify the investment of time and money, and so human welders will continue to be the best and most efficient option. The technology is constantly evolving, however, with collaborative robots becoming more efficient and having greater capabilities. Additionally, artificial intelligence will play an increasing role that will further improve the efficiency and adaptability of robotic welding.

Although robotic welding is not ideal for all industries, the scope will expand as technology continues to grow and develop. This will make it a technology that becomes more widely available and suitable for many other types of companies. If you are at all unsure about the technology and its suitability for your company, get in touch, and we will provide all the help and advice you need.