Direct glazing

In addition, with direct glazing windows can be used as design and engineering elements of a car body (flush glazing). One- or two-component adhesives are used, which can be applied either warm or at room temperature and which are moisture- or hot-curing or... 

Figure 10 Sketch of automatic manufacturing equipment for direct glazing.

Heating and ventilation systems Seat buckets Backrest linings Head and rear light housings Direct glazing... 

Wilhelm E, Wellnitz J (2011) RPM—Rotatory piston machines new class of innovative machines. The first water based pretreatment system for direct glazing. In Hung S et al (eds) Proceedings of the third international conference (ICSAT) on sustainable automotive technologies 2011. Springer, Berlin, pp 67-71... 

Figure 1 Direct glazing of windshield glass to metallic frame on a ship.

In 1964, another key development started when the US automotive industry had to fulfill safety standards which required the retention of the windshield in a crash and thus, to ensure that the occupants remained inside the car (FMVSS 212). The windshield bonding technology involved has been called direct glazing ever since. At that time, direct glazing was achieved by the use of a material which... 

This perception changed after the introduction of direct glazing in the European automotive industry at the AUDI AlOO in 1978. All other car manufacturers then introduced this technology, stepwise one model after the other. The reason was not only to fulfill the US safety standards, but engineers soon realised that direct glazing increased the torsional stiffness of a car significantly at no additional cost. 

Figure 4 (continued) (b) Direct glazed front cabin bonded to the train. 

Direct glazing - the installation of window glass by means of adhesives (Fig. 26) - is one of the most common applications of Elastic Bonding Technology and the technique has been widely used in the car and bus industry for a number of decades. 

Figure 26 Direct glazing correct and incorrect joint designs.

Figure 27 Dimensioning adhesive joints for direct glazing.

Sika introduced a primerless direct glazing system to the car industry in 1986, although the glass surfaces need to be treated with a reactive cleaning agent or activator that prevents the ingress of moisture into the bond-line. 

On the other hand, automotive manufacturers prefer to bond without using a priming system. In 1987, a primerless direct glazing system was successfully introduced in the automotive industry which renders the black primer obsolete in many applications. 

Car manufacturers would like to bond windshields in such a way that it allows an immediate transfer to the next assembly station without the need of fixtures. Here, a precured pasty, direct glazing adhesive is warmed up to 80°C and applied along the side of the windshield. After pressing the windshield into the frame of the vehicle, the windshield remains in position after a short time with the help of physical hardening due to adhesive cooling (No. 3 in Fig. 64). The SDAT is achieved after 1 h (No. 4 in Fig. 64). 

After application, within about 30 min (No. 6 in Fig. 64) the Booster system remains pasty and allows positioning, for example, at direct glazing. The adhesive cures completely within the next few hours. 

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. 

Direct glazing adhesives are multi-functional and can cope with several demanding specifications. They are based on a modular system, described in Fig. 70. 

Figure 70 Modular system of a direct-glazing adhesive.

Crash suitable direct glazing adhesives were formulated in several ways. The applications are ... 

Fig. 74 describes features and benefits of some common direct glazing adhesives. All the adhesives noted in Fig. 74 have excellent performance with SDAT times between 1 and 4 h. 

This direct glazing adhesive is applied at room temperature and is used when the customer does not require the vehicle immediately. After skinning time of 12 min, the strength is built up. The SDAT is 4 h for SikaTack -Drive under these conditions. The adhesive cures fully within 7 days to an elastomer. 

The Sikaflex -555 direct glazing adhesive possesses the highest mechanical properties of products currently in Sika PUR-Hybrid product range (Fig. 84). The lap shear, tensile and tear strengths are higher than those of comparable MS-products. 

Plate 26 Modem trains owe their stylish looks to a combination of glass, plastics and lightweight metals bonded together with adhesives, (a) Train before cabin bonding, (b) Direct glazed front cabin bonded to the train. 

Direct glazing is a common application in the automotive industry since the polyurethane sealant can perform the important functions of adhesion of glass directly into the metal frame, cope with the vibration and movement and still remain weather tight. The Sikaflex -255FC is a one-component compound from Sika which, because of permanent elasticity and excellent adhesion to metal, glass, and many other materials, is ideal for the automotive industry. 

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