Topic of the Month in October: The power of light serving the automotive glass industry

Laser coating removal on glass & films

The last decade has seen significant improvements in the application of solar control glazings in cars. The main drivers are:

• Passenger comfort
  
• Lowering the load on the car's air conditioning unit and thereby decrease fuel consumption
  
• Minimising the degradation effect of the sun's radiation on interior trims

The increasing market demand for high performance solar control products has lead the automotive glass suppliers to develop an infrared reflecting glazing. It consists of either a metallic coating applied directly onto the glass or onto a film laminated between two pieces of glass, this glazing reflects more than four times the sun's energy compared to a standard glass.

The introduction of infrared reflective glasses, which effectively improve the solar control, had a negative impact on infrared based detectors mounted behind the glass. Indeed devices such as "Telepass” windows (automatic motorway payment) or rain sensors request a non-coated glass area.

Compared to current techniques of coating removal such as abrasion (mechanical) , or masking (metallic mask or tape applied on the glass surface before the coating process) LASEA S.A. has developed an innovative solution to remove the coating by laser.
The laser offers advantages compared to other solutions:

• Non aggressive process for the glass substrate
  
• Flexible. The designs can be modified by a dedicated computer interface
  
• Insignificant variable costs (electrical consumption of the laser is equivalent to an iron)
  
• Low maintenance

Due to its electrical properties, the infrared reflecting coating gives additional benefit to the automotive glass as :

• Heating : de-icing and de-misting of coated windscreen (using 24V power supply)
  In this case, the laser technology is used to create specific and aesthetic patterns to isolate electrically the coating and to obtain a homogenuous temperature on the glass surface.
  
• Glass Antenna
  In this case, the laser technology is used to design complex and invisible patterns to provide the basis of a glass antenna system. It allows car designers to move away from traditional whip antenna to improve the styling and aesthetic appeal of the car.

Source: OGIS GmbH, glassglobal.com
in cooperation with: Laser Engineering Applications S.A. Contact: G.Heraly (+32/ 4-365-02-43)