sample legging SS2010 collection CG by Conny Groenewegen

 Laser in textiles; silk satin, cotton satin and a perforated lycra legging.

To have a good result with laser in textiles the fabric needs to be flattened to the surface, which usually happens through the build in vacuum pump. The first difficulty we needed to resolve was the defect of the build in vacuum pump in the machine in Amsterdam. Instead of sucking the fabric to the surface it blowed air. Therefore we fixed the fabric to a flat surface which was put on top of the laser table. We used rib-cardboard which is firm and lightweight. The cardboard was cut to the same measurements as the machine table: 860 x 460mm.

Silk satin.
A satin-woven fabric tends to have a high lustre due to the high number of floats on the fabric. Floats are missed interlacings, where the warpyarn lies on top of the weftyarn, or vice versa. The floats tend to make the fabric look glossier as well as give it a smoother surface.

For the first experiment we folded satin silk in 6 layers on top of the cardboard. The fabric was laced together by hand stitches in distant rows of 2 cm. The bottom layer was fixed to the cardboard with repositionable adhesive spray mount. For the second test we used repositionable adhesive in between all the layers to avoid the time absorbing lacing technique. Each layer of fabric is sprayed before it is folded and flattened on the former layer. The final surface counts 6 layers of fabric to be cut by laser.
After our laser fabmoment, the fabric was carefully loosened layer after layer and handwashed with little soap. The perforated gold coloured satin was looking great with the small holes and a bit of brownish edges that gave a rough expression to the smooth silk. Soon we would find out that the strength of the yarn was actually ruined. With the least bit of tension the fabric would rip. Therefore we did more experiments with cotton satin.

Cotton satin
The cotton was closely woven which made the fabric more firm. With the cotton it worked out super nice. We could use the fabric for pants and dresses. Even with holes of 2mm diameter and inbetween spaces of 2,5 mm the fabric kept strength. Our fabmoment resulted in a modern semi transparent strong fabric.

Machine setting for silk and cotton:
power 100
speed 5
dpi 500
ppi 900

Lycra
The third experiment was executed with a lycra fabric in a delicate quality. The lycra remained flexible and firm enough (with 2,3 mm holes at distance of 2 mm) te be used for a legging.

Preparation for cutting: The instability of this fabrics is solved by a piece of paper used for making patterns with a heat-fix coating at the back. With the iron we first heat-fix the paper to the lycra before cutting the patterns out of the fabric. The stabelised lycra (fabric+paper) is folded and fixed tot the cardboard surface, in the same manner as described above for silk and cotton with repositionable adhesive spray mount. We fix 6 layers of fabric+paper which makes a total of 12 layers. 12 Layers seems to much; either the laser isn't strong enough to penetrate all surfaces, or the laser is to strong and burns the material which becomes useless. Another discovery is that we need to alternate lycra and fabric for each layer. Two layers of lycra touching eachother will melt together by the heat of the laser. We decide for a second test to work with alternate layers of lycra and paper until a total of 6. With paper tape we fix the edges. After our laser fabmoment we discover a brownish glow on the lycra which is left behind by the burned paper. The glow seems oily on the shiny lycra, and is actually adding a nice expression to the fabric. The lower layers are less perforated (smaller holes, bigger spaces in between) then the upper layers which adds an extra dynamic to the overall effect.

Machine setting for lycra+paper, 6 layers:
power 100
speed 5
dpi 500
ppi 900