Sika’s OEM* Approved Adhesive Systems meet or exceed Vehicle Manufacturers Requirements.
Not only does the windshield allow vehicle occupants to easily view the road, it is also an important part of your vehicle’s safety system. To operate effectively, the airbag depends on the windshield to deflect off of in the event of a crash. If the windshield is not bonded correctly the glass has the potential to detach from the vehicle body, putting the occupants at great physical risk. Many of today’s vehicles have been specifically designed to utilize the windshield as a structural component of the vehicle body by providing increased torsional stiffness. Vehicle manufacturers are careful to select special, high-modulus polyurethane (PUR) adhesives to bond the windshield to these specific vehicles. Relying on the windshield as a structural member, the high-modulus adhesive also allows the OEM1 to minimize the thickness of the steel used to build the car, thus reducing weight and costs.
Vehicle Manufacturers have different specified criteria, and those criteria are explained below.
Chemistry & Mechanical Performance
Automotive OE manufacturers are using high performance polyurethane adhesives to bond windshields. OEM specifications demand high mechanical strength values. Vehicles, whose windshields came bonded from the factory using high modulus adhesives, also require high modulus in case of aftermarket windshield replacement. Sika‘s All-in-One Modulus adhesives can be used for all vehicles both at the OEM or in the field.
All Automotive OEM’s use pre-treatment systems such as Sika Aktivator or black-primers as adhesion promoters on the windshield. OE manufacturers can control their environment as well as the quality of glass better than aftermarket users; however, it goes without saying that cleaning the windshield and removing contamination, as well as using the adhesion promoters is still essential for the best quality windshield replacement.
FMVSS Crash Standards
Obviously one of the most important functions of the wind shield is to prevent the ejection of occupants in case of an accident. Incorrect installation processes and unrealistic Safe Drive Away Time can put occupants at enormous risk during a crash. Real world studies have shown that many vehicle occupants do not wear their seatbelts, placing even more emphasis on a properly installed windshield. The only relevant safety standards that test for windshield retention in case of a crash are the Federal Motor Vehicle Safety Standards (FMVSS) 212 and 208. The FMVSS 212 / 208 Standards are applicable for passenger cars, light trucks and buses. When Sika tests its adhesives for the Safe Drive Away Time, Sika always applies the most severe test conditions during the crash test. Sika uses cars that require high retention demand on the bond line, as well as crashing in climatic conditions that are not favourable for the adhesive. Finally Sika performs their crash tests using unbelted dummies, which places greater stress on the adhesives
Windshields equipped with integrated radio antennas are becoming more popular. Vehicle manufacturers are therefore specifying adhesives which are “Antenna Suitable“, so as to ensure proper signal reception.