Jena, Germany—The growing integration of airbags in door and interior trim parts, seats, and the use of textile covers for instrument panels in cars require preweakening of the material. In the past expensive special seams were provided at the points of opening, which challenged the designers' creativity. Several manufacturers, together with Jenoptik Automatisierungstechnik GmbH, searched for and developed a safe laser solution for this problem.
The main problem was the open pores of the loops of the textile and the fluctuation of laser light penetration. So the group focused on the processing of textiles with and without substrate material. They learned from processing coated samples that the process was safe if the laser holes of the preweakening were generated alternatively in the compound material. The microperforation software controls the laser with such accuracy that individual holes with different depths of penetration can be generated, allowing different weakening of the substrate and the textile cover (see the photo).
Holes with different depths of penetration allow different weakening of the substrate and the textile cover.
Preweakening of textiles without substrate also produced good results with microperforations closely pitched in a row with the depth of the holes controlled as above.
A 50W CO2 laser weakens textiles at 30–50 mm/sec creating a mean tensile strength of 250 N/5 cm. The most promising results were achieved with warp and weft fabric made of PP fibers.
The laser system for preweakening, to be marketed under the Jenoptik Votan product label, has been submitted for the 8th Automotive Division Award in the Body Interior category. After an October exhibit it will be available for tests at the Customer Applications Center at Jenoptik. You can email the company at email@example.com.