The latter part of 2020 revealed that manufacturers, regardless of their industry, continue to find value in robot implementation. The non-automotive sector’s jump to the No. 1 slot for robot orders reinforces the idea that robotic technologies can be an incredibly effective solution for a variety of manufacturers struggling to overcome a plethora of challenges.
This is especially true for the robotic welding market, which is expected to grow at a compound annual growth rate (CAGR) of 8.9 percent through 2028, according to a 2020 study from Intrado GlobalNewswire. Yet, for all the issues and applications robots can alleviate in this realm, most companies seem to take the robot leap based on the same core struggles: a lack of skilled labor and a need for greater weld consistency and quality and faster cycle times.
Labor shortages
Drastic changes in the employment landscape over the last decade have generated valid concerns about the lack of skilled labor to fill the widening job gap. Welders capable of
handling multiple weld processes are becoming a rare commodity. By 2024, the American Welding Society projects a shortage of more than 300,000 skilled welding professionals to help fabricate the 50 percent of all products that require some form of manual welding.
Despite beneficial science, technology, engineering and math (STEM) education initiatives, the deficit continues to grow. To compensate, company leaders are identifying areas for robotic automation where robots with well-defined parameters can assist.
Whether it is to complete a task that human employees are physically unable to do or to accomplish high-turnover work that would otherwise remain undone, robots and their peripherals are conquering dull, dirty, dangerous and difficult applications. This satisfies the need for highly trained workers, and the utilization of robotic tools provides fabricators with other transformative benefits, propelling competitive advantages and enhancing monetary gains.
Keep in mind, however, that robots still have limited abilities and qualified personnel are required to build, program, operate and maintain them. Thus, employers should be cognizant throughout the implementation process via retraining, redeploying and incentivizing current workers (when needed) to facilitate worker satisfaction and greater productivity.
Welding consistency
There are multiple culprits for inconsistent welds. For example, there could be issues concerning:
- Worker fatigue – even incredibly talented welders still get tired, potentially committing errors or ignoring routine shift maintenance that leads to inconsistent welds.
- Unique worker deviations – creative liberties or a mixed level of pride taken by an individual worker in their welding quality.
- Supply chain – deviations in the parts coming in to be welded.
- Tooling – may not match changed parts or could be wearing out, leading to defects.
No matter the cause, unacceptable welds can be detrimental, especially where safety-critical welds are concerned. For this reason, a growing number of fabricators are implementing highly repeatable robots that demand well-fitting parts.
In conjunction with these reasons, greater focus can be given to a weld procedure specification (WPS) – a formal document that describes welding procedures for creating consistently identical welds that are engineered for that particular part. A WPS is typically developed for each material alloy and welding type used, and it is usually driven by the use of preferred welding techniques or specific codes used onsite.
AWS/ANSI B2.1 Specification for Welding Procedure and Performance Qualification outlines the essential electrical characteristic variables as: heat input (J/in) = (volts x amps x 60)/travel speed (ipm).
This is based on the output of the power source, and few power source manufacturers use variables directly related to the output. Key process parameters typically include wire feed speed, arc voltage/arc length, travel speed and other weld settings.
Whether a plant adheres to a strict WPS for safety critical welds or has yet to implement a documentation process, robots are programmed to apply these same parameters consistently. For example, a robot program determines torch angles and travel speed, which are two essential variables of a WPS. Plus, robotic arms can generally store weld settings as global files or in the weld instructions local to a specific program, facilitating greater traceability of parts.
Along with data tracking via the robot, sensors can be integrated for weld inspection. For a redundant part with variations that tooling and part consistency cannot resolve, there is usually a sensor that can. Especially beneficial for automotive, aerospace and other industries that require safety-critical welds, arc monitoring from the power supply is ideal and is combined with individual scans of the weld to track each part that comes through production.
While it cannot necessarily determine a good versus a bad weld, it can identify welds out of process tolerance. In a sense, this serves as a figurative insurance policy that can reduce widespread part recalls and the heavy liability that comes with any potential part failure.
Welding quality
Closely related to weld consistency and traceability, the quality of a weld is also a classic, key driver for robot utilization. If WPS documentation is maintained, the robot control should offer several helpful features. For example, weld settings and program editing can now be restricted and logged by activating a security level, limiting the personnel that can gain access and make changes. This may include a unique login or tiered password for qualified individuals.
The robot control should also have a feature for displaying the data necessary to document a WPS. This may include information on torch angles for weld location, weld lengths and travel speed as well as amperage and voltage feedback while welding. A simple number display may be used in the robot control, or a more visual display may show actual values along the length of a weld.
Another consideration is the capability of the robot itself. Typically, human welders are limited to 2 ft. to 3 ft. on a single start/stop pass where robots, like the Yaskawa AR3120, can travel seamlessly up to nearly 17 ft. This is equal to a human welder starting and stopping approximately eight times.
Production time
As mentioned, human workers are prone to fatigue, requiring breaks and slowing production. In an ever-changing market, optimizing cycle time is essential to satisfying
diverse customer demands in a timely manner. Not only do extremely fast and highly repeatable robots contribute to the reduction of cycle time, they can also help create a prime situation for predicting downtime.
Whether harnessing data via a robot or from a factory automation machine monitoring system, companies can use the information gained to enable proactive decision-making for customized operations and predictive maintenance.
Regardless of the industry, robots and other advanced tools, such as sensor technologies, work together to address common issues fabricators face. From delivering greater efficiency and experiencing fewer errors to completing less rework and lowering cycle times, the advantages are clear by helping struggling job shops and plant operations around the world.
