Multilayer picture frame

Abstract

The invention relates to a picture frame which can be covered with a textile fabric as a canvas and consists of a plurality of wedge strips connected to each other to form the picture frame, which are equipped with flame retardant properties, characterized in that the wedge strips (1) are designed in such a multi-layered manner that two outer strips (2) made of wood or wood fibers enclose and are connected to an inner strip made of metal (3).

Description

[0001] The invention relates to a picture frame which can be covered with a textile fabric as a canvas and consists of a plurality of wedge strips connected to each other to form the picture frame, which are equipped with flame retardant properties.

[0002] Pictures – framed paintings, collages, photographs, and the like – are not only displayed in museums but also frequently in public spaces. These include, for example, hospitals, town halls and other public buildings, event venues, and exhibition halls, all of which are subject to applicable fire safety regulations. As a rule, it is required that pictures displayed there also meet fire protection class B1. Hospitals, in particular, are very interested in exhibiting art, also to offer patients distraction and intellectual stimulation, but they must reject corresponding exhibition proposals from artists if these do not comply with fire safety regulations. Museums generally have special fire protection systems, so that art that does not meet fire protection class B1 can generally be exhibited there.

[0003] For young artists in particular, access to exhibition opportunities in public spaces is essential, especially for gaining public recognition. Therefore, there is a need for venues where framed works, in particular, can be exhibited. However, a prerequisite for exhibiting framed works in such venues is that the facilities meet fire safety regulations.

[0004] Picture frames made of wedge-shaped strips are standard, especially for paintings, to provide the necessary tension to the canvas. Wooden frames, provided they are sufficiently thick, are generally stable enough to withstand this tension. However, additional stabilization is advisable, particularly for large paintings, but also for frames constructed from thin wedge-shaped strips. In such cases, cross braces are often fitted to the back of the frame. These braces represent an additional fire hazard.

[0005] When using fiberboard strips for picture frames, additional stabilization is advisable, especially to limit the thickness of such strips. The advantage of fiberboard strips is their relatively simple flame-retardant treatment.

[0006] The object of the invention is therefore to provide a frame construction that is flame-retardant and complies with applicable fire protection regulations, i.e., falls into fire protection class B1. At the same time, such a frame construction should exhibit sufficient stability to allow the tensioning of a canvas without warping.

[0007] This task is solved with a picture frame of the type mentioned at the beginning, in which the wedge strips are designed in such a multi-layered way that two outer strips made of wood or wood fibers enclose and are connected to an inner strip made of metal.

[0008] The picture frames according to the invention are primarily stretcher frames used to stretch a painted canvas that is to be painted or covered later. For exhibition purposes, such a stretcher frame is often covered with a decorative picture frame that does not have a stretching function.

[0009] Preferably, the two outer strips of the wedge strips are made of wood fiber strips, in particular medium-density fiberboard (MDF). Medium-density fiberboard, so-called MDF panels, which can easily be cut into strips, are commercially available in various thicknesses with a flame-retardant finish. They have the advantage that they can be readily bonded to a metal surface, preferably by gluing. Flame-retardant adhesives are known.

[0010] The frame members are preferably profiled wedge-shaped members with specially designed corner joints. Wedge-shaped members joined at such angles can be further reinforced with dowel joints, such as flat dowels, which are generally not glued. Connections using metal brackets are also possible, as are screwing or doweling at the ends, or a connection using crossbars extending over the corners, which can be screwed through the wedge-shaped members. However, a connection of the outer members using flat dowels, usually made of wood, such as those available under the Lamellos brand, is preferred. Flat dowels made of metal, especially aluminum, are also preferred.

[0011] The outer strips of the wedge-shaped strips are preferably made of wood fiberboard with a thickness of 5 to 19 mm and a width of 4 to 8 cm. These are typically strips cut from medium-thickness wood fiberboard with a density of 0.8 to 1.0 g / cm³. Any type of wood can be used for solid wood.

[0012] The metal strip enclosed by the outer strips is advantageously 1 to 3 mm thick, particularly about 2 mm. The metal can be, for example, iron or steel, but is preferably aluminum. Aluminum provides the wedge strip with the necessary stability against twisting under tension. In case of fire, the outer strips protect the metal from the heat.

[0013] For the flame-retardant treatment of wood fiber-based moldings, mineral materials are primarily used, for example, those based on boron compounds – such as borax – phosphorus compounds – such as sodium or calcium phosphate – aluminum hydroxide, or calcium carbonate. These materials, in a finely ground state, are pressed together with the wood fibers and a binder – usually a synthetic resin. Such products meet fire protection class B1.

[0014] If the wedge strips are made of solid wood, the flame-retardant treatment is achieved through impregnation with suitable mineral salts. A known chemical process involves the reactive introduction of calcium carbonate into wood. Pressure-treated wood and wood impregnated with siloxanes are suitable. These products also meet fire protection class B1.

[0015] The wedge strips of the picture frames according to the invention generally have a total thickness of 12 to 44 mm. If the outer strips are thin, a greater thickness of the metal strip, for example 2 or 3 mm, is recommended. When connecting via flat dowels, these are fitted into the outer strips.

[0016] It is also easily possible to connect the wedge strips at the corners of the picture frame by galvanizing them.

[0017] To provide a work that complies with fire safety regulations, the canvas stretched over the picture frame according to the invention must also be flame-retardant. Such a fabric can be made, for example, of linen, cotton, or polyester, with polyester being preferred according to the invention. Such fabrics are commercially available. Phosphorus salts or organic phosphorus compounds are preferably suitable for the flame-retardant impregnation. Since the canvas does not need to be washed for the performing arts, such impregnation is sufficient and durable. Textile fabrics impregnated with organic phosphorus compounds have been described in numerous publications. Flame-retardant textiles are also used, in particular, on the stage in theaters and opera houses.

[0018] Accordingly, picture frames equipped with non-flammable canvas, as described above, are part of the invention.

[0019] In test trials, frames and screens equipped according to the invention were tested for flame retardancy according to DIN 4102-1 (fire protection class B1). All tested samples proved to be flame retardant.

[0020] The invention is explained in more detail by the accompanying illustration.

[0021] Figure 1Figure 1 shows the end face of a wedge strip 1 according to the invention for the corner area of ​​a picture frame, showing its layered structure. Two outer MDF strips 2 are glued to an inner aluminum strip 3. The wedge strip 1 has an angle of 45° to the direction of the strip. It is attached to the corner area of ​​a picture frame with a correspondingly cut and shaped wedge strip, whereby flat dowels are inserted into the recesses 5 in the usual manner. The wedge strip 1 is profiled at 4 in the edge areas of the upper outer strip 2 for tensioning a canvas. The profile 4 can be rounded outwards. The canvas is fixed and tensioned on the stretcher frame thus produced using staples in the usual manner.

[0022] The special design of the picture frame according to the invention prevents the frame from warping during canvas stretching. The aluminum strip inside the frame is essential for stability and freedom from warping. Conventional stretcher frames tend to warp under the tension of the stretched canvas, if not immediately, then after some time.

[0023] The stretcher bars are simply slotted together. They can be secured by screwing them together at the ends. Stretching the canvas over the stretcher bar is done in the usual way and requires no special tools.

[0024] The picture frame according to the invention, when stretched with a flame-retardant canvas, is entirely non-combustible. All materials are selected to be non-flammable according to DIN 4102-1. This applies even to the adhesive used to manufacture the frame.

[0025] For picture frames manufactured according to the invention of a certain size—especially when they cover a large area of ​​the wall—it can be advantageous to install soundproofing and / or thermal insulation on the back of the frame. Thermal insulation would be particularly useful for large-format pictures mounted on exterior walls to protect them from temperature fluctuations. It is understood that such soundproofing or insulation is also flame-retardant and, for example, is arranged directly inside the inner frame in the form of a foam mat. Such a foam mat is suitable for improving the acoustics in the room and simultaneously has no adverse effect on the fire protection properties.

Claims

1. Picture frame which can be covered with a textile fabric as a canvas and consists of a plurality of wedge strips connected to each other to form the picture frame, which are equipped with flame retardant, characterized by the fact that the wedge strips (1) are designed in such a multi-layered manner that two outer strips (2) made of wood or wood fibers enclose and are connected to an inner strip made of metal (3).

2. Picture frame according to claim 1, characterized by the fact that the two outer strips (2) of the wedge strips (1) are wood fiber strips.

3. Picture frame according to claim 1 or 2, characterized by the fact that the outer strips (2) are medium-density fiberboard strips.

4. Picture frame according to one of claims 1 to 3, characterized by the fact that the outer strips (2) are flame-retardant impregnated.

5. Picture frames according to one of the preceding claims, characterized by the fact that the metal strip (3) is an aluminum strip.

6. Picture frames according to one of the preceding claims, characterized by the fact the metal strip (3) has a thickness of 1 to 3 mm.

7. Picture frames according to one of the preceding claims, characterized by the fact that the wedge strips (1) have a total thickness of 12 to 44 mm.

8. Picture frames according to one of the preceding claims, characterized by the fact that the wedge strips (1) are connected to each other at the corners of the picture frame using flat dowels.

9. Picture frame according to one of claims 1 to 7, characterized by the fact that the wedge strips (1) are connected to each other at the corners of the picture frame by galvanizing.

10. Picture frame according to claim 8, characterized by the fact that the flat dowels are made of wood or aluminium and are joined together with the wedge strips (1).

11. Picture frame according to one of the preceding claims, characterized by the fact that the layers (2, 3) of the wedge strips (1) are joined together by gluing.

12. Picture frame with canvas stretched on it according to any one of claims 1 to 11, wherein the canvas is flame-retardant.

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