Luxinar, lasers and the fashion industry blog

Laser-marked denim jeans

Introduction

Since its invention in the USA in 1964, the CO₂ laser has been widely used in industry, mainly for cutting and welding metals, and since the 1970s, for medical applications in areas such as dentistry, and facial surgery. But what is perhaps less well known is the crucial role that CO₂ laser technology has played in textile processing. In this blog, Louise May, Luxinar’s Senior Applications Engineer, looks at how Luxinar’s CO₂ laser sources are helping to revolutionise fabric processing in the technical textile, automotive and fashion industries.

What is a laser?

LASER stands for ‘light amplification by stimulated emission of radiation’ – a concept first proposed by Einstein in 19161. Although there are many different types of lasers, they all follow the same basic principles: an electric charge is passed through a material (the laser gain medium) exciting the material’s electrons, which move to a higher-energy state. After a few milliseconds, the electrons return to their original energy level, and in the process give off photons that are amplified to produce a laser beam at a frequency determined by the gain medium.

What is a sealed CO₂ laser?

Animation showing how Luxinar's sealed CO2 lasers work

Fig 1. Principles of a Luxinar sealed CO2 laser

In the case of a Luxinar sealed CO₂ laser, the gain medium is a gas mixture of carbon dioxide, nitrogen and helium inside a sealed tube containing two slab electrodes cooled by water. A mirror is placed at each end of the tube to form an optical resonator with one of the mirrors being partially reflective to allow light to exit the resonator.

When an electric charge is applied to the electrodes, in this case, radio frequency (RF) power, the gas molecules are excited, and as they lose energy, photons are emitted. The photons travel back and forth within the resonator, stimulating the emission of more photons as they collide with the excited molecules. As the photons all travel in the same direction, in phase and with the same wavelength, a laser beam is produced at a frequency of between 9.3 and 10.6 micrometres (represented as µm with 1 µm equal to one millionth of a metre) in the long-wavelength infrared spectral region.

CO₂ laser cutting of textiles and fabrics

A CO₂ laser emits a high-powered infrared beam of intense heat which can vaporize and thus cut through a wide range of fabrics such as cotton, polyester, silk, and nylon, as well as thicker fabrics such as leather and canvas.

Compared with traditional mechanical or manual cutting, CO₂ laser cutting is much faster, more precise and reduces waste as parts can be cut very close together. In addition, it produces clean-cut edges that require minimal post-processing – and as it’s a non-contact process there’s no tool wear, no distortion or stretching of fabric during cutting.

With synthetic fabrics, the edges are sealed, which prevents fraying; and although natural fibres are prone to discoloration, this can usually be controlled with a careful choice of laser parameters. These advantages add up to faster and more consistent processes that are easily automated, with design changes quick and easy to implement, thereby reducing downtime and time to market.

cutting edge fashion

Garment production: In recent years, laser cutting has helped to streamline garment production across the industry.  Cutting room processes can now be fully automated, with the speed and efficiency of laser cutting minimising both downtime and fabric waste.  Laser cutting is flexible, allowing designs to be created and modified with ease, enabling manufacturers to keep up with rapidly changing fashions.  One-off, customised and made-to-measure garments have become much easier and more cost-effective to produce, men’s suits being a prime example.  The client’s measurements are sent to a production facility, where a CAD system designs the pattern, and a laser cuts out the fabric.  The finished suit is delivered to the client within weeks, at a fraction of the cost of a traditionally tailored garment.

Automotive industry: Laser cutting is now also commonplace in the automotive industry. Synthetic fabrics can be cut cleanly, and the laser melts and seals the edge of the material so that it doesn’t fray during the subsequent stitching and assembly. Both real and synthetic leather can be cut for car upholstery in the same way. The fabric coverings on the interior pillars of modern vehicles are frequently finished by laser. Fabric is bonded to these plastic parts during the moulding process; excess material is then removed using a 5-axis robotic process, with the cutting head following the contours of the part and trimming the fabric with precision.

Airbags cutting

Airbag processing: Airbag materials are usually made from densely woven nylon or polyester fibres and are often silicone coated to obtain the desired air permeability. Airbags may be flat woven, where the bag is made up of several fabric pieces stitched together or one piece woven (OPW), where the structure of the airbag is fully formed on the loom. Both types require trimming, for which a CO₂ laser is the ideal tool.

The laser process is efficient and reliable, minimising waste by cutting with consistently high quality. The non-contact nature of the process means that handling of the fabric is minimised, and the silicone coating is therefore less likely to incur any damage which may compromise the integrity of the airbag.

CO₂ lasers can also be used to score lines in the material of the car dashboard and door skins, selectively weakening the structure so that a flap breaks open to release the airbag in the event of a collision. This laser scoring must be performed to extremely tight tolerances and is implemented on the reverse side of the interior panels, so there is no aesthetic impact visible to the occupants of the vehicle.

Laser cut textiles

Technical textiles: Lasers are also advantageous for the cutting of curtains, carpets and sails as well as thermal insulation material, medical gauze, filter material, geotextile membrane, and Kevlar-reinforced textiles. Cutting profiles for these materials can be complex and highly detailed, and consistency of quality is of paramount importance. By cutting technical textiles with lasers, the edges of the fabric are sealed, which prevents fraying, eliminates the need for further finishing and allows easier handling of the cut pieces.

Luxinar’s solutions for textile and fabric cutting

A good choice for textile cutting is Luxinar’s SR series of sealed CO₂ lasers. They come in three wavelengths: 10.6, 10.25, and 9.3µm, and are integrated with field replaceable RF power supplies. The minimum shipment power is 20% higher than rated power and this series can be easily integrated into laser-based processing machines.

Luxinar sealed CO₂ laser sources for textile cutting: SR series
125W SR 10i  SR 10i data sheets175W SR 15i  SR 15i data sheets250W SR 25i  SR 25i data sheets
Also available is Luxinar’s SCX 35, a versatile 350W sealed CO₂ laser source that’s an ideal choice for cutting and airbag processing. It comes in 10.6µm, 10.25µm, and 9.3µm wavelengths, has a separate RF power supply for flexible integration, and is designed for robotic applications and integration into industrial processing systems with scanners or other beam guidance components.
350W SCX 35  SCX 35 data sheet

Laser marking and engraving

In addition to cutting, CO₂ laser technology is used for marking (where only the surface of the fabric is processed) and for engraving, i.e., controlled cutting to a depth.

Leather shoes and bags processed by laser

Leather processing: Natural and synthetic leather materials are used in the fashion industry to make shoes, bags, belts, and clothing. Lasers are involved from the very beginning of the leather production process, being used to mark traceability codes on the animal hides prior to tanning.

Lasers are also used to cut processed leather at high speeds, and intricate designs can be created with ease. The laser produces a good finish, minimises waste and offers tremendous flexibility. Lasers can be used for texturing as well as cutting, removing the surface of the leather to create a pattern or design. This may be purely decorative, or it may be functional – for example texturing leather for non-slip shoe soles.

Laser marking of buttons: Buttons used in clothing often have decorative or functional logos, patterns or manufacturer’s details, and these can be laser marked.

Luxinar’s solutions for button and leather marking

Luxinar’s 125W CO₂ laser marking systems, the MULTISCAN® HE and MULTISCAN® VS, offer an inkless method of applying alphanumeric text, QR codes, 2D and traditional barcodes, as well as complex graphics to leather, wood, plastic and a wide variety of other materials. The flexible software allows intelligent data to be placed anywhere within the specified scan area, and the system can mark stationary objects or moving products which need to be coded on the fly.  Both models are available in 10.6µm, 10.25µm and 9.3µm wavelengths and can be easily integrated into existing production lines.

Luxinar’s 125W CO₂ laser marking systems
MULTISCAN® HE MULTISCAN® HE data sheetMULTISCAN® VS MULTISCAN® VS data sheet

Engraving heat transfers for T-shirts

Laser engraving heat transfers for T-shirts

Engraving can be used to create designs on heat transfer film that are used to decorate T-shirts and other fabric garments. In this case, the laser is not used directly on the garment itself. Instead, it engraves a type of laser-friendly transfer film, removing excess material and leaving only the required design intact. The design is then transferred to the garment using a heat transfer press. The advantage of fully engraving the film is that the transfer doesn’t require “weeding” before use – the time-consuming process of removing small pieces of waste material from the design, which significantly reduces the total process time.

Designer denim

A 450W laser removing indigo dye pigment from denim jeans to create a vintage look. Source: Jeanologia

The first use of CO₂ lasers for marking textiles was in 1995, when Icon, a small startup in Florida, patented a laser-based colour-fading process for dyed denim garments and fabrics. The process was based on the vaporization of indigo dye using high-power CO₂ lasers. The aim was to create a retro look – a symbol of youth and rebellion as epitomised by a Levis advertisement in the late 1980s. In this ad, model and musician Nick Kamen put rocks in a laundrette washing machine and undressed to his boxer shorts to perform some DIY stonewashing/fading on his 501 jeans. Sales skyrocketed and set a retro fashion tone for denim jeans which is still with us today.

In 1998, Icon licensed the process to Levi Strauss who installed high-power denim-marking systems in their flagship stores in San Francisco and London. Until then, stonewashing and sandblasting were the only methods to simulate the look of a well-worn pair of jeans – methods which created massive environmental damage as they involved the discharges of millions of litres of contaminated water and the use of harmful chemicals.

Since the early 2000s, companies like Luxinar have done much to advance the technology by providing state-of-the-art CO₂ lasers to the world’s major suppliers to the denim jean industry. A CO₂ laser finishing system typically involves 4 stages: 1) a digital image of the jeans is created; 2) the image is overlaid with the desired features of a vintage pair to form a greyscale design; 3) the greyscale design is loaded into the laser computer; 4) the laser transfers the greyscale design to the jeans by varying the intensity of the focused laser beam as it scans rapidly across the garment. A 450-1000W laser beam then sweeps across the jeans and selectively removes the indigo dye pigment from the denim by heating it to a temperature of 600oC in a process called sublimation.  The same laser can be used to introduce rips, abrasions, various wash effects and simulated creases, known as “cat’s whiskers”. 

Fig. 2 Comparison between laser and mechanical abrasions/fading. Source: Textile Today

As Cherry Healey quipped in a 2023 BBC documentary on jeans manufacturing “Using a laser on jeans seems more James Bond than Bond Street”. This may be true, but the fact remains that compared with manual methods, CO2 laser processing can produce an equally good finish without damaging the texture or compromising the strength of the fabric (see Fig 2). And not only is the process more sustainable and eco-friendly – it also enables a dramatic increase in productivity as with laser processing the effects of years of wear are created in seconds compared with 20 minutes for manual methods.

Luxinar’s solutions for denim applications

Luxinar sealed CO₂ laser sources for denim applications: OEM series
OEM 450W 45iX  OEM 45iX data sheetsOEM 650W 65iX  OEM 65iX data sheetsOEM 1kW 100iX OEM 100iX data sheet

A popular choice for denim applications is Luxinar’s OEM series of sealed CO₂ lasers, which range in power from 450-1000W and come in 10.6, 10.25, and 9.3µm wavelengths.

Denim marking requires the laser parameters such as power, mode, wavelength, and polarisation, to be very stable. For this reason, Luxinar’s lasers incorporate unique cavity and electrode designs to ensure the required level of stability and pulse-to-pulse consistency. Additionally, they have a high quality, round, symmetrical beam for high processing speeds and a short optical pulse with high peak power, which combine to ensure optimum process quality and minimise the heat-affected zone.

As with the SR series, our sealed OEM CO₂ laser sources are based on the well-proven slab principle, with no need for gas recirculation equipment such as vacuum pumps or pressure control systems. As gas exchange is unnecessary before 20,000 operational hours, the running, maintenance, and service costs of our lasers are minimal – resulting in a long lifetime and trouble-free operation throughout.

Future outlook

The outlook for the laser processing of textiles and fabrics is promising.  According to a recent market report3, the fabric cutting machine market will be worth US$ 429.5 million by the end of 2024, rising to US$ 644.4 million by 2034, with the laser cutting segment accounting for around 42% of the market. Laser cutting is expected to grow exponentially during this period due to the inherent advantages of laser sources over traditional mechanical and manual processing methods. As we have seen, these include faster processing, greater precision, a reduction in waste, enhanced quality control, and a reduction in downtime and time to market. 

The future for laser denim processing is also positive with the global market for denim jeans projected to rise from US$ 64.5 billion in 2022 to US$95.2 billion by 20304. Along with this growth in sales will be an increase in demand for laser marking driven by the trend towards greater customisation and exclusivity, as well as the advantages of being faster, more eco-friendly, and conducive to greater productivity.

We are also likely to see an increase in the use of innovative technical fabrics based on recycled plastics, cellulose, vegetal fibres and other bio-fabrics. These materials will require a new generation of consistent and reliable laser performance. But whatever the future may bring, Luxinar’s expertise and experience in developing innovative CO₂ laser source technology, make us well placed to meet any new challenges and remain a leading provider of laser sources to the denim and textile industry.

References

1. Wikipedia article on simulated emission

2. https://www.bbc.co.uk/iplayer/episode/m001v63x/inside-the-factory-series-8-3-jeans

3. Future Market Insights: Fabric Cutting Machine Market

4. Research & Markets: Global Denim Jeans Strategic Business Report 2023

About the author Dr Louise May is senior applications engineer at Luxinar Ltd, where she is responsible for testing and qualifying industrial processes in the lab.  She has over 14 years of experience in laser applications, preceded by five years in CO₂ laser R&D.  Louise obtained a BSc in Applied Physics from the University of Hull in 1994, followed by a doctorate in the optical characterisation of semiconductors in 1998.
About Luxinar Headquartered in Kingston upon Hull, UK, Luxinar has been at the forefront of laser technology for more than 25 years and is a leading manufacturer of sealed CO2 and ultrashort pulse laser sources. The company has an installed base of over 25,000 lasers worldwide in the automotive, electronics, packaging and textile industries for applications such as ablating, cutting, drilling, marking, perforating, scribing and welding.

Luxinar head office building

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