CO2 galvo laser marking and engraving on jeans and denim cloth
CO2 laser is now widely used in the textile industry. It is mainly used for decorations and in fabric finishing. The CO2 laser’s wide range of applications has substituted traditional operations in the textile industry most of which are polluting, slow and costly.
It's well known that the textile industry is one of the most polluting industrial sectors. Fortunately, the use of laser technology has allowed it to embrace a more environmentally friendly production process and greatly reduce its impact on the planet. Laser marking and engraving have substituted traditional operations such as sanding or washing, greatly reducing the consumption of water, chemical substances and energy.
Denim is one the most popular fabrics in fashion and therefore a perfect example of the wide ranging applications laser technology can have on textile. The introduction of a galvo laser processes, such as laser marking and engraving, has brought big advantages to fabric finishing for jeans.
Denim and CO2 laser, the perfect pair
Denim fabric is made from dyed cotton fibre. The typical colour is usually indigo but many other colours are also used. Denim was born as a sturdy fabric for work clothes. Though it is typically used in the fabrication of jeans, it is now transformed into all types of garments.
In jeans finishing, laser is used for marking applications: the laser passes quickly over the fabric surface, creating a physical or just visual change to the material, depending on the thickness of the area being worked on. The thickness can go from a few fractions of a micron to a few hundred.
In the marking process, the laser works on a surface layer. This process substitutes the phases of dry or water based discoloration and gives the garment a distressed look.
The engraving process works more in depth. It modifies the fibre of the fabric. For this reason, the obtained result is also tactile. Laser engraving can be done on a localised part of the finished garment or over the whole fabric.
In both cases, the system which is used is the same and based on 3 fundamental components.
How does a system of marking and engraving based on CO2 galvo laser work?
A galvo laser system for denim marking and engraving is composed of a CO2 laser source, a scanning head and a control software.
The CO2 laser source is the device that generates the laser beam. In the El.En. product line we have different devices that can be used for denim laser marking and engraving, such as for example, the Blade RF Self Refilling laser source.
The laser scanning head is the device that allows the laser beam to move across the surface. The scanning head is composed of three main elements. Two galvanometric mirrors and one z-linear optics. The galvanometric mirrors direct the laser beam along the X and Y axes. This movement is performed at a very high speed. The z-linear optics keep the laser beam focused on the area being worked on. Because the distance between the laser and the surface constantly changes, the beam has to be constantly refocused on the surface in order to concentrate its energy on the correct point. By changing its focal length in real time, the z-linear optics allow the laser beam to always remain focused. El.En produces both complete scanning heads like Gioscan or galvanometric mirrors and z-linear optics.
The software is the brain of the system. It controls the power of the laser source, the speed at which the galvanometric mirrors move and the focus. The software transfers the inputs given by the system into shapes to be drawn on the surface.
This basic system can be implemented on different types of machines. The results that can be obtained are wide ranging. By controlling the laser parameters, the software can achieve results such as:
- a worn effect
- various types of discoloration
- tactile effects
- engravings of designs or patterns
- engravings of various types of images
The advantages of laser markings and engravings on denim with CO2 galvo scanner systems
Compared to traditional processes, the use of laser has undeniable advantages:
- The production process can be completely automated. The laser is a digital production process, managed by a computer. The production results can easily be standardised and controlled down to the smallest detail.
- It’s an environmentally friendly process. Laser denim decoration is a dry process. There is no water and energy waste or use of potentially polluting chemical substances.
- It’s a flexible process that allows for constant experimenting. Not only does laser permit the experimentation of geometric patterns, but it also makes it possible to transfer images directly on a surface. It is much faster and cheaper than methods like serigraphy.