Page 186 - Industrial Cutting of Textile Materials
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Automated laser cutting of textile materials                      173

           embroidery machine, if it is necessary to continue the job. The laser cutter can have
           two work surfaces to increase productivity. The galvanometric laser cuts at the same
           speed as a laser bridge, which is up to 10 times faster than plotters. The power of
           standalone lasers is 25–100 W. The most commonly used is 50–60 W.

           10.8.3.3   Laser bridges
           The laser bridge can be installed over any multihead embroidery machine, rhinestone/
           stud setting machine, or Schiffli embroidery machine. It is formed from a galvanomet-
           ric laser head with CO 2  laser beam that runs along a horizontal bridge supported by
           two lateral columns. The head controlled by servomotors can stop in the exact position
           to do cutting, engraving, or marking on the embroidered garment or fabric. Cutting
           area is most often 30 × 30 cm. The bridge can be expanded to operate with more than
           one embroidery machine and designed to travel over nonembroidery stations (cutting
           tables and fabric roller devices). The bridge can be programmed to perform very dif-
           ferent tasks in the same time, for example, to cut embroidered pieces on some stations
           and cut or engrave/mark on others. It can be used for doing high-volume production
           and small orders. The laser power is from 50 to 200 W.
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              The companies that manufacture laser embroidery equipment are Proel  (Italy),
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                                                    15
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               18
           GMI  (Italy), BITO  (United States), Golden Laser  (China), GBOS Laser  (China),
           and others.
           10.9   Laser cutting of textiles of different origin


           Textiles of different origins differently react on laser treatment creating different kinds
           of desirable and undesirable changes in the material structure.

           10.9.1   Textiles of natural origin (cotton, linen, wool, silk)

           Natural organic materials vaporize quickly when cut with a laser resulting in smooth
           edges. Annealing marks in light brown/orange tone can appear on the cut edges. The
           thicker is the fabric, the more apparent are the marks. After the cutting, the edges of
           the fabric can still be frayed. Most often, single-ply cutting is performed. Multi-ply
           cutting can be also used, processing appropriate number of plies with high-power laser
           in slow cutting speed.
              In performing the laser marking, most part of natural fabrics are marked in a brown/
           orange tinge. Indigo-colour denim fabrics lose their colour treated by laser, and the
           marks on the fabric surface appear in white colour. The dense fabrics are more suitable
           for marking than light ones. When marking very light fabrics, the laser beam can cut
           the material through.



           18  http://www.gmi.it
           19  http://www.bitousa.com
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