SK252011U1 - Bonded safety glass - Google Patents

Abstract

The present invention relates to bonded safety glass, particularly for automobiles and construction, which consists of two layers of glass (1, 3) between which a film (2) is located, wherein a flexible layer (instead of a film (2) is applied in the edge region). 4).

Description

The solution relates to glued (laminated) safety glass, especially for car windows or for use in the building industry. However, it can be used in general for all types of bonded glass. It is particularly useful wherever further processing of bonded safety glass is necessary to hold the glass in the tool for subsequent processing. This may be, for example, processing in plastic injection molding machines. However, the solution is equally applicable to windows that are intended for installation as windows in door and roof systems.

BACKGROUND OF THE INVENTION

Glued safety glass, as commonly used in the automotive industry, normally consists of two layers of glass, between which there is a polymer layer, also called a film. This foil performs various functions, such as e.g. improvement of mechanical properties, reduction of acoustic noise, increase of safety, minimization of infrared radiation, eventually others. The most commonly used material for these films is PVB (polyvinyl butyral), PET (polyethylene terephthalate), or other materials.

German patent document DE 10 2009 025 972 A1 discloses a glued safety glass consisting of a standard glass-polymer-glass composition, which in addition to this known composition contains an additional layer, the so-called glass. layered structure. It is essentially a layer consisting of a plurality of layers of relatively small thickness, typically less than 5 μιτι, which can fulfill the function of electrochromatic, photovoltaic, light-emitting or heating. All of them

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The 33587 / T layers are arranged parallel to each other (glass-polymer layer-laminate-glass). At the same time, by determining the temperature expansion range for the two glass layers used, the mechanical stresses that occur when using the finished glued glass within the considered temperature range are minimized.

However, the improvement in the physical properties of the bonded glass according to this document is not optimized in view of the specific conditions encountered in the processing of glass in a plastic injection molding or other extreme handling.

Every processing of a workpiece consisting of glued safety glass of the necessary shape, from which the final product - window is made by gluing the appropriate seals or fixing clamps or other elements, is assumed to be held directly in the processing tool or in a tool allowing further processing. . The tool may be e.g. plastic injection molding machine, clamps for mechanical clamping or other type of tool.

By holding the glass in the processing tool at the point of contact of the tool surfaces with the glass, there is an increased mechanical stress on the glass in the edge area. As a result, glass rupture and production losses occur quite often.

The increased stress of the glass in the marginal regions is due both to the need for the glass to be held in the processing tool and to the limited possibilities of accurately adapting the processing tool to the actual glass geometry. The increased stress in the marginal region is also conditioned by the size of the clamping force of the gripping tool or the manufacturing tolerances for the glass blank from which the finished product is to be made.

In the manufacture of an automotive window gasket, stress may occur when the glass is held in the injection molding machine at the point of contact of the injection mold surfaces with the glass, resulting in deformation and subsequent glass breakage.

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In addition, various fasteners and systems (such as clamps, etc.) can be inserted into the injection mold together with the glass, which are used e.g. to attach the moldings or to attach the window to the body. When the injection mold is closed, these fasteners then contact the glass. In places of increased pressure on the glass, glass breakdowns then occur.

To form a window seal, the plastic (PVC, EPDM, PU, etc.) to be applied on the edge of the window is injected into the injection mold under high pressure and at high speed by means of an injection nozzle. Sufficient pressure must be applied to completely fill the cavities in the injection mold. The amount of injection speed and pressure depends on the volume of the cavity of the injection mold cavity. This results in increased stress on the glass at the injection points of the plastic into the injection mold cavity - directly below the injection nozzle.

The essence of the technical solution

The object of the present invention is to overcome the above-mentioned disadvantages and to provide a bonded safety glass that is more resistant to the type of stresses mentioned, thereby avoiding unnecessary production losses.

Investigating the effects of glass destruction in the marginal portion at various stages of glass processing, it has been found that the fracture region can be affected and limited by replacing the film in the critical marginal region with a layer having specific properties and whose load behavior allows to minimize glass cracking and thereby significantly reduce losses .

The essence of the invention lies in the fact that between the two layers of glass, instead of a standard automotive foil of the PVB, PET, etc. type, in the peripheral (or peripheral) region, instead of a standard automotive film. use an elastic layer whose thickness corresponds approximately to the thickness of the film. Typically, the film thickness is about 0.8 mm. The thickness of the elastic layer can also be slightly greater than the thickness of the foil, e.g. 10% or more, depending on the particular type used

33587 / T elastic material. This region is then able to allow the edge of the glass to adapt to the external action of forces caused by e.g. clamping the glass in the processing tool. This creates a laminated glass composition that provides a more even distribution of the pressure exerted on the glass from the outside and prevents unwanted rupture in the critical area.

Since the area where the elastic layer is intended to be located around the perimeter of the future window, the effective area on which the window is to be transparent does not diminish.

In particular, the elastic layer material to be used to eliminate the disadvantages of glass processing must be sufficiently flexible to provide the necessary flexibility. At the same time, it shall have properties that meet the car manufacturers' specifications for laminated glass, such as: requirements for resistance to climate change (VW TL1200), and other requirements defined in the standards of automotive glass manufacturers, e.g. VW Norme TL 957, Daimler DBL5610, General Motors GME01101-1-4., Porsche PTL 8903. they degrade over time, they are not suitable.

In addition, the elastic layer material must also comply with the temperature range within which the finished product is to be used, which is, for example, from -40 ° C to +90 ° C. However, this temperature range is determined by the purpose of using the laminated glass, therefore, the thermal resistance of the flexible layer can be designed specifically for a higher temperature load as necessary.

For ease of application, the flexible layer may be formed by a flexible double-sided tape, such as e.g. EPDM tapes (ethylene propylenediene monomer), polyurethane tapes (PU), acrylic tapes, or adhesive tapes, such as those available on the market, e.g. company TESÁ, 3M.

BRIEF DESCRIPTION OF THE DRAWINGS

The solution will be described with reference to the figure showing:

33587 / T fig. 1, FIG. 2 fig. 3 shows a glued glass according to the prior art in a cross-sectional view of a glued glass according to the present invention in a cross-sectional view of a glued glass according to the present invention in frontal view

Examples of technical solution

Comparative Example 1

In FIG. 1 shows an example according to the prior art. The bonded safety glass consists of three layers: glass 1, foil 2 and glass 3, which are shown in an unconnected state. As shown in FIG. 1, the middle layer represented by the foil 2 extends to the edge of the three-layer blank. Thus, the edge of the film 2 is located at the edge level of both the glasses 1 and 3.

Example 1

As shown in FIG. 2 and 3, in addition to the known composition of glass 1, film 2 and glass 3, the laminated safety glass also comprises a flexible layer 4 in place of the foil 2 in the peripheral part.

This glued safety glass was made of two glass panes, designated glass 1 and glass 3, having the shape of a future window. PVB-type film 2 was applied over the entire surface to the glass. In the region around the periphery of the glass sheet 1 approximately 6 cm from the edge, the film was removed and a double-sided adhesive tape was placed as elastic layer 4 in this region. Subsequent joining of the two panes 1 and 3 together in a known manner resulted in the successful formation of a bonded glass which contained, as an intermediate layer, a foil 2 in the central part and an elastic layer 4 in the form of a double-sided adhesive tape in the peripheral respectively. peripheral part.

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In the stress test, it has been found advantageous that the fracture boundary of the glass can be controlled relatively precisely by positioning the range (or point of contact) of the film 2 and the elastic layer 4. Thus, the fracture boundary of the glass stress.

Industrial usability

Glued glasses according to the present invention have a wide application in the manufacture of windows wherever it is to be expected that the glass is handled in such a way as to exert forces in the edge of the glass which can cause it to break.

In particular, this solution is applicable to glasses which are further processed by means of injection molding machines for plastics or, possibly, to glasses which are intended for installation in car door or roof systems, but also in the building industry.

Claims (3)

1. Glued safety glass, in particular for motor vehicles and construction, consisting of two layers of glass (1, 3) with a film (2) between them, characterized in that a flexible layer (2) is applied in the edge area instead of the film (2). 4). Glass according to the preceding claim, characterized in that the elastic layer (4) consists of a commercially available double-sided adhesive tape. Glass according to any one of the preceding claims, characterized in that the elastic layer (4) is applied in the edge region at a width from the edge where increased mechanical stress is assumed during further processing of the glass, e.g. in injection molding machines for plastics, eventually during subsequent assembly eg. for cars, building structures, etc.