As part of their efforts to achieve the challenging targets on fuel consumption and CO2 emissions that have been set by various governments around the world, in recent years, vehicle manufacturers and their suppliers have been pursuing aggressive vehicle mass reduction programmes and one of the areas for potential mass reduction that has been identified is the use of plastic rather than glass for all of the vehicle’s glazing, including the windscreen.
For many years, the United Nations Economic Commission for Europe (UN ECE) Regulation on safety glazing, ECE Regulation No. 43, has included requirements covering rigid plastic glazing. However, the Regulation only permitted the use of such rigid plastic glazing for panes other than windscreens.
In 2010, initial discussions on updating the requirements of ECE Regulation No. 43 to allow for the approval of both rigid plastic and laminated rigid plastic windscreens took place within the UN ECE Working Party responsible for glazing; the Working Party on General Safety Provisions (GRSG). As a result of these discussions, it was agreed to set up a dedicated Informal Group to develop the necessary requirements and associated test procedures. This Informal Group was tasked with identifying and, where necessary, developing the tests necessary to ensure that plastic windscreens provided an acceptable level of safety, with particular regard to durability, abrasion, weathering, UV stability and chemical resistance.
Between January 2011 and June 2014, this Informal Group met ten times and developed a set of revisions to ECE 43.01 to cover rigid plastic windscreens, laminated rigid plastic windscreens and laminated rigid plastic panes other than windscreens. In the majority of cases, the requirements that the Informal Group identified for application to these new types of plastic glazing were based on the existing requirements contained within ECE 43.01, e.g. headform impact testing, light transmission testing, optical distortion testing, fire resistance testing, etc. However, it was the abrasion testing requirements that generated the most discussion.
ECE 43.01 already included an abrasion test, known as the Taber test, in which samples of the glazing are subjected to abrasion testing via abrasive wheels. However, the Informal Group developed three new tests to specifically cover the abrasion testing of plastic windscreens:
- A sand drop test to simulate the abrasive effects of dust and sand hitting the windscreen.
- A car wash test to simulate the abrasive effects of car wash brushes on the windscreen.
- A windscreen wiper test to simulate the abrasive effects of the windscreen wipers on the windscreen.
For plastic glazing, the Informal Group decided that these three new tests should be offered as an alternative to the Taber test, rather than replacing it. Therefore, glazing manufacturers will be given the option of testing their plastic glazing to either the Taber test or the three new tests.
All of the amendments to ECE 43.01 that were developed by the Informal Group have now been published as Supplement 4 to the 01 series of amendments to ECE Regulation No. 43, which has a date of entry into force of 8th October, 2015.