Laser Welders Best For The Environment

Laser welding has very large environmental benefits compared to arc welding such as TIG, MIG and stick welding.  Simply stated, this is because the reductions in processing time directly reduce all the impacts of welding operations.  We break down these energy savings and the related environmental or ecological benefits to explain them below.

Today there is increasing pressure from government and society to reduce CO2 and hazardous emissions, while saving electricity.  As becomes apparent below, laser welding is quickly becoming essential for manufacturers and fabricators not just for financial and operational reasons, but also to meet EH&S (EHS) targets.  

Electrical Energy Saving

This table shows the complete calculation of TIG and laser welding energy use for a butt weld on 1/8″ (3mm) stainless steel, for a given weld distance.  It does not include the many additional environmental benefits which are explained in subsequent sections.

Neil Silke 21 Feb 2024	TIG	LASER	LASER
	Generic	G5-2000WC	Lightwelder20
Arc current	140	n/a	n/a
Arc voltage	26	n/a	n/a
Welding power(kW)	3.64	1.5	1.5
Speed cm/min	20	72	72
kW-hours to weld for 1 minute	0.061	0.025	0.025
kWh to weld 1m (100cm)	0.303	0.035	0.035
Conversion efficiency %	63.5	32	42
TOTAL kWh input to weld 1m	0.478	0.109	0.083
Percentage of energy vs TIG	100	23%	17%
Base Energy saving vs TIG	0	77%	83%
TIG uses how many times more:	1	4.4	5.8

TIG data source:  https://www.lindedirect.com/frequently-asked-questions/welding/what-are-the-tig-welding-parameters-for-stainless-steel

TIG efficiency source:  Generic competitor in https://www.millerwelds.com/resources/article-library/welding-guide-to-power-efficiency

Laser welder information source:  Published data from laser-welder.com.au

The final output of the calculations above is that our water cooled laser welders uses less than 1/4 of the energy of a typical TIG weld (23%), while our super efficient air cooled laser welder Lightwelder15 or Lightwelder20 save even more, using only 17% as much electricity as TIG.

Less Waste

The critical factor is that laser welding is so much faster then TIG, typically around 5 times as fast.  This means the operator is not sitting there pumping excess heat in, but it also means they are not pumping excess argon or nitrogen shielding gas into the weld area for that time.  On top of that, laser welding’s localised and focused heat input means the critical temperature for weld staining is not exceeded for some welds, or at least not for long. This leads to a much smaller amount of shielding gas being used.

Waste also takes other forms such as straightening, pre-processing/cleaning and post processing via grinding, sanding and pickling.  Preparation is reduced because laser welding can often be done straight over oxides and coatings, thanks to the laser beam’s cleaning action.  Refer to the main image above, where galvanized steel is being welded over directly without pre or post processing.  A laser welder reduces rework because it has about 1/4 of the distortion of arc welding, no spatter, and smaller, neater welds that require little if any processing.

The higher quality welds mean less scrap, and higher corrosion resistance,so the product lifecycle is extended. This has knock on savings throughout the supply chain.

Laser welding is normally done with a much smaller fillet, but the deep penetration and avoidance of overheating (annealing) the base metal and weld zone means the welds are normally at least as strong.  This has been proven in testing by independent test centres.  This saves on filler wire.

Of course the smaller staining and ability to quickly switch to cleaning mode mean less acid or pickling paste, with direct environment and health benefits.

Knock-On and Organizational Savings

Much faster throughput and reduced rework mean less workers, less factory space and hence less administration.  This means a smaller facility with less staff, less people tied up driving to and from work, and hence a smaller overall environmental footprint.

Better Air Quality Through Fume Reduction

Air quality is improved by laser welding through three key areas:  Preparation, welding and Post Processing.

Laser welding requires zero or minimal preparation of the base materials.  This is stark contrast to TIG and MIG, which require deep grinding of the workpiece by veeing-out.  This grinding consumes abrasives and fills the air with metal, ceramic and fibre particles.  All are very concerning for lung health and air quality.

Of course, once the V has been cut it then needs to be filled again(!) which requires a lot of filler material and heat.  This molten metal and the nearby burnt coating such as zinc generate welding fumes.  Laser welding has far less of all of these factors, resulting in less fumes.

Finally, after welding with MIG, and to a lesser degree TIG, the welds usually require cleaning.  This is done by grinding and/or sanding, which makes dust and releases burnt metal and abrasives into the atmosphere.  Acids also create fumes and some are very nasty.  Laser welders generate neglible rework.

Conclusion

Laser welding has large and real advantages in every aspect of the production process, compared to arc welding.  It enables more efficient and faster production.  Industries using lasers end up with a smaller operation, a smaller footprint, less energy use, less gas and material consumption, and lower emissions with enhanced air quality.

All of our laser welders offer these benefits, with our air cooled models Lightwelder15 and Lightwelder20 offering slightly greater electrical savings.