Case Study: Adhesive Promotes Unbreakable Displays in Automotive Applications
A new high-tech adhesive prevents glass splinters in vehicle crashes.
SCHOTT and DELO® Industrial Adhesives have collaborated to develop an unbreakable glass cover composite for vehicle navigation and entertainment screens, in which a high-tech adhesive bonds the display to the special glass cover. In a series of tests, both companies demonstrated that their new displays satisfy all safety requirements imposed by the automotive industry and protect occupants of vehicles against cutting injuries.
The two companies tested how completely bonded displays behave in a crash compared to conventional displays with an air gap between the glass cover and LCD. For this purpose, they conducted head-on crash tests according to the criteria of the international ECE R21 standard in which a steel ball with a weight of 14.99 lb (6.8 kg) impacts on the displays with a speed of approximately 15 mph (24.1 km/h).
In the tests, the standard displays were completely destroyed by the steel ball, and hundreds of glass splinters were blown off in all directions by the impact. In contrast, only the inner liquid crystal display of the completely bonded displays with the special SCHOTT glass broke. The glass covers remain completely intact, which protects the passengers against cutting injuries.
High-Strength Special Glass and Flexible High-Tech Adhesive
For the tests, the floated aluminosilicate glass Xensation® cover made by SCHOTT was used. This glass type is especially suitable for displays due to its high strength. The gap between display and glass cover was filled with a special DELO adhesive; this bond increases the durability of the composite and its resistance to oscillations and shocks.
The adhesives used are highly flexible and optically completely transparent. In addition, they pass the thermal, humidity and UV yellowing tests of the automotive industry. Their index of refraction is adapted accordingly. Therefore, they clearly reduce disturbing reflections and provide strong contrast. The adhesives can be light-cured within just seconds, taking account of the short cycle times demanded by automotive manufacturers.
High Passive Safety Required
Data from the World Health Organization (WHO) show that seat belt use in the backseat is compulsory in only 111 countries, excluding the United Arab Emirates and the U.S. states of New York and Michigan. What is more important than the legal provisions is the acceptance of belts. Germany, with a usage rate of 97% in the backseat, is a positive exception. The U.S. reaches a quota of 70%. Russia (8%), the Emirates (5%) and Mexico (4%) trail way behind. Unbreakable displays protect both backseat passengers and front seat occupants against severe cutting injuries.
SCHOTT is an international technology group with more than 130 years of experience in the areas of specialty glasses and materials and advanced technologies. Its core markets are the household appliance, pharmaceutical, electronics, optics and transportation industries. Its workforce of 15,400 employees generated worldwide sales of $2.5 billion for the 2012-2013 fiscal year. For more information, visit www.schott.com.
DELO is a leading manufacturer of industrial adhesives, headquartered in Windach near Munich, Germany. In the past fiscal year ending on March 31, 2014, 400 employees generated sales revenues of almost @60 million (~ $82 million). The company supplies tailor-made special adhesives and complementary equipment for applications in special lines of business – from electronics to the chip card and automotive industry, as well as in glass and plastic design. For more information, visit www.delo.us.