From Handbook of Adhesives and Sealants, Volume 2

6.8 Elastic Bonding in Practice

In this section, different applications of Elastic Bonding Technology are described.

6.8.1 Crash-Resistant Direct Glazing Adhesives

One-component polyurethane adhesives for direct glazing are widely used in the automotive industry. Since about 5% of car's windshields every year are damaged, efficient and reliable replacement methods are of increasing importance. To achieve short safe-drive-away time after replacement of windshields, the adhesive must meet extremely strict requirements.

The definition of Safe- Drive- Away Time (SDAT) is the time required for curing of the windshield adhesive to achieve full passenger retention in the case of a defined crash (Fig. 69).

Drive-away time defines the fit-for-use of vehicle after windshield repair.

In case of an accident the bondline must withstand impact loading of

  1. Airbag pushing against the windshield.

  2. Momentum of the vehicle occupants thrown forward against the air bag.

Figure 69: Definition of Safe-Drive-Away Time.

With short safe-drive-away times, costs are reduced and customers can put the car in service faster. To achieve windshield retention in the event of a frontal barrier impact, partly cured adhesives must have high initial tensile strength and fracture energy. Additionally, they must also fulfill the original equipment specifications such as good corrosion resistance, antenna suitability and mechanical performance.

Before conducting the expensive sledge test and full crash test with a car, extensive laboratory experiments are generally carried out at high speeds on various lab test machines, including small falling weight towers, impact pendulum and high- speed tensile testers.

Products & Services
Double Sided and Transfer Tapes
Double sided tapes are coated with adhesive on both sides of the backing or carrier. Transfer tapes consist of a thin adhesive film without a carrier or backing.
Adhesive Tapes
Adhesive tapes are used to assemble materials or parts together using a sticky chemical bond. Adhesive tapes are made by coating a backing or carrier (paper, plastic film, cloth, foam or foil) with an adhesive on a web or roll coater.
Epoxy Adhesives
Epoxy adhesives are chemical compounds for joining components. They require clean surfaces and are valued for their toughness and resistance to chemical and environmental damage.
Pressure Sensitive Adhesives (PSA) and Contact Adhesives
Pressure sensitive adhesives (PSA) and contact adhesives adhere to most surfaces with very slight pressure. They are available in solvent and latex or water-based forms.

Topics of Interest

6.9 The Future of Elastic Bonding Elastic bonding is recognised as a key technology which opens up many new possibilities in industrial manufacturing. Its main strength lies in its...

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Elastic design, avoiding plasticity, ensures that the cabin of the car does not deform in a crash. Plasticity absorbs the energy of impact, and allows metals to be shaped and polymers to be molded.

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