DE20105877U1 - Polyurethane (PUR) profile with internal glass fabric reinforcement - Google Patents

Description

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Joachim Kleiß, Albrecht-Dürer-Str. 25,97337 Dettelbach 22.10.2001

Utility model application

Title: Polyurethane (PUR) - profile with internal glass fabric reinforcement

Profiles made of polyurethane integral rigid foam are used as window and door profiles and, for example, as insulators between a steel substructure and a glass roof on top in hall construction (see Figure 1, letters a, f and e as glass insulation profile GD 50/30). To achieve sufficient stability and the smallest possible change in length under the influence of temperature, the PUR foam must generally be reinforced with metal. This is done by foaming the metal rods, as described, for example, in patents No. 3408.975 and 3408 995. The disadvantage here is that the otherwise good thermal insulation of the PUR profiles is significantly impaired by this metal reinforcement. This can be shown, for example, with the glass insulation profile in the attached drawing, Figure No. 1 (Fig. 1, letter bd). The profile without metal reinforcement provides good thermal insulation, but has the disadvantage of being very stable and leads to shrinkage at the longitudinal joints, particularly when made in dark colors. For these reasons, these profiles are generally reinforced in practice with an internal aluminum profile, which is placed in the foam mold during the production process and foamed on all sides. This in turn causes a significant deterioration in thermal insulation, because now only the PUR edge thickness is effective at the thinnest point in the vertical passage.

PUR integral rigid foam is also characterized by the fact that it forms higher-density edge layers, where the thermal conductivity is significantly worse than that of the low-density core. As a result, the overall thermal insulation of the metal-reinforced profile is often insufficient.

For example, such PUR profiles can now be reinforced with glass fiber chips; however, with foam this is only possible with long fibers that are difficult to process and only on special filler dosing systems.

According to the invention, the problem is now solved by using glass fabric mats (letter d, alternatively e) instead of metal inserts in a glass insulation profile of this type as shown in Figure 2. This material is inexpensive, provides sufficient profile reinforcement, reduces the coefficient of linear expansion to almost zero and can be easily processed on endless rolls because it is available in many qualities. The good thermal insulation of the PUR material is hardly, i.e. not measurably, impaired by this, so that the desired temperature profile outside / inside (Figure 2, letter a) is achieved as in the case of a design without metal inserts.

By selecting different fabric threads and their spacing, the degree of reinforcement can be adapted to requirements and the desired strength properties can be dimensioned. The mesh size can be used to determine the screw pull-out strength, among other things.

The glass fiber fabric is cut into the foam mold and, due to its mesh structure, the liquid PUR material flows around and through it during the foaming process. Fixing in the foam mold can be done in several ways, namely a fabric strip can be placed on the bottom part of the mold and, after the mold is closed, stretched over the separating surfaces (letter b) and thus secured against displacement.

Alternatively or additionally, the fabric can be pressed into a desired position in the mold cavity by means of corresponding pins or strips (letter c) on the upper and/or lower part. The strength of the profile can be further increased by special shaping of the fabric.

Alternatively, pre-formed pieces made of particularly strong fabric (armor fabric) can be inserted into the mold by folding and fixed in a desired position using the pins or strips mentioned above. By placing the fabric on pins that fit into the mesh, the insert can be securely fixed in the foaming tool to prevent it from moving.

Attachment:

Figure 1 and 2

Claims (1)

1. Profile made of polyurethane integral rigid foam (PUR) with foamed reinforcing insert made of glass fibre fabric ( Fig. 1, letter f), characterized in that - the foamed reinforcement consists of mesh-shaped glass or textile fabric with longitudinal and transverse threads, - the thickness of the longitudinal and transverse threads as well as their position in the profile including the mesh size is adapted to the desired degree of reinforcement. - the meshes are large enough to ensure complete penetration of the fabric by the PUR material which is liquid in the reaction phase, - the glass fibre fabric is shaped in such a way that it can be fixed in place during production in two-part or multi-part foam moulds by clamping it between the closing surfaces and the protruding part can be cut off together with the foam burr after the profile has been removed from the foam mould, - the glass fibre fabric is shaped in such a way that it is pressed into the desired position by pins or webs in the foaming tool when closing, - the glass fibre fabric can optionally also be made as a pre-formed cut, primarily made of inherently stable fabric with stronger longitudinal fibres, - the glass fibre fabric consists of several layers, e.g. a strong one with a larger mesh size - and a weaker one with a small mesh size, in the case of a fabric molded part this is designed in such a way that the exact fixation can be achieved by hooking the meshes over existing pins in the foam mold and thus the edge is fabric-free.