SK166998A3 - Press pad - Google Patents

Abstract

The padding material, for insertion into a laminating press to distribute the pressure, is composed of intersecting filaments (4), composed of a metal wire (6) or wires (3), wound round a core filament (5).

Description

PRESSING CUSHION

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a compression cushion for use in laminating presses with intersecting fibers, wherein fibers having a fiber core are used, which at least on its outside consists of a rubber-elastic material and is wrapped with at least one metal wire.

BACKGROUND OF THE INVENTION

The production of laminated materials, for example decorative coated particle board, is carried out in laminating presses, which may be in the form of low-pressure or high-pressure tray presses or short-acting presses. Press cushions are used, the task of which is to distribute the pressure evenly and over the entire surface onto the material to be pressed. The press cushions must be able to withstand the high pressures and temperatures arising at these pressures and be capable of rapidly and without major losses transferring the heat coming from the press plates to the press material, i.e., have high thermal conductivity in this direction.

Press cushions are known in the prior art which consist of a single fabric comprising two types of fibers (EP 0 493 630 A1). In the first group, the fibers are metal or contain a metal component to improve heat transfer to the molded material. There are a number of designs for the second group of fibers, for example fibers of aromatic polyamide (EP 0 493 630 A1), silicone elastomer (DE 295 18 204 U1) or rubber, heat-resistant or similar plastic monofilament (EP 0 713 762).

EP 0 493 630 A1 describes monofilament or multifilament metal threads or those in which the metal fibers are wrapped around the textile thread. In EP 0 493 630 A1 nothing is said about the wrapping method. At

No. 088 / B press cushions according to DE 295 18 304 U1 are metal fibers intended for metal fibers, i.e. braided metal wires of copper, brass or steel.

In addition, it is proposed to cover the outer side of the silicone coated metal wires with braided stainless steel wire. The production of such fibers is extremely difficult, especially the interlocking of steel wire. In addition, an uneven, wrinkled surface is achieved. It has been shown that in this way only the point contact between the press cushion and the press material is ensured and is thus poor, resulting in limited heat transfer.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a compression cushion of the type described above in order to improve heat transfer and thereby accelerate the heating of the molded material and to be manufactured at a lower cost.

SUMMARY OF THE INVENTION

According to the invention, this object is achieved in such a way that the metal wire is at least partially wrapped, respectively. the metal wires at least partially wrapped around or around the rubber-elastic core are tangled metal wires. Such fibers which, on the one hand, are compressible on account of their rubber-elastic component, on the other hand, are provided with at least one metal wire on the outside and preferably with complete core coverage, are easy and cost-effective to produce in comparison. They have a constant circular cross-section and have a comparatively smooth surface, even if they are made of multiple metal wires. This greatly improves contact with the press plate or the material to be pressed, thereby improving the heat transfer. It is expedient for the core fibers to be wrapped in at least two layers of metal wires, preferably in each layer with complete covering.

According to a further embodiment of the invention, the rubber-elastic material is believed to have a hardness of 60-75 Shore-A. This hardness favors the laying of transverse fibers and hence the strength of the fabric. In addition,

088 / B of this hardness, the residual compressibility of the fibers according to the invention remains for a long time.

For the rubber-elastic material, all materials having rubber-elastic properties and capable of withstanding the temperatures in the presses are suitable. Silicone elastomers are particularly suitable. A foamed rubber-elastic material, preferably having a density of from 0.3 to 0.5 g / cm ³ is recommended as one of the most suitable materials.

For metal wires, materials having a high thermal conductivity should be used. In particular, copper or strength modified copper alloys are offered here. In this way, the high thermal conductivity and favorable cost of these materials for the invention relating to the compression cushion can be utilized. It is particularly advantageous to use non-annealed copper (hard copper) because it has high strength. However, annealed copper (soft copper) is also possible.

In order to obtain, on the one hand, a stable and rigid but sufficiently ductile press cushion, the fibers should have a diameter of at least 1 mm, preferably at least 1.5 mm.

There are different possibilities for soul fibers. Heat conduction is required when the core is formed as a metal wire, a metal strand and / or metal fibers, with metal wires wrapped around the central fiber. Textile materials such as plastic monofilament or multifilament materials are also contemplated, with heat-resistant materials such as aramid, PPS, PEK, PEEK or the like being suitable.

Of the known methods, the core fibers should consist of a central fiber and around it a braided rubber-elastic material to increase the strength of the fibers. The central filament may be formed as a plastic monofilament or multifilament, or as a metal wire, metal strand or metal fiber, with metal wires entangled around the core fiber.

088 / B

According to a further embodiment of the invention, it is envisaged that the braided metal wires are partially braided in a S-shape and partly in a Z-shape, which can be expediently solved alternately. In this way, the travel of the press cushion in the press can be effectively prevented.

The fibers described above may be combined with metal fibers which do not have a rubber-elastic component, but in which the metal or plastic central fiber is wrapped with at least one metal wire. Alternatively, metal wires may be entangled around the central filament. In both cases, the benefits of the above-mentioned advantages are obtained because a very smooth surface and thus a good heat transfer is achieved. Such metal fibers may be contemplated if heat transfer is not sufficient for the above-described rubber-elastic component fibers.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of the fibers for the press cushion; and Fig. 2 is a side view of another fiber for the press cushion.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a fiber 1 for a compression cushion not shown here. It is intended for a fabric, such as a woven linen or twill bandage, that is, as a transverse fiber. Such fabrics are used as compression cushions or as base fabrics for compression cushions.

The fiber 1 has an elastomeric core 2 of silicone elastomer which, as not shown here, encircles the central fiber, which can be made in any desired manner, for example as a metal or plastic fiber.

Six metal wires are braided around the elastomer core 2 - marked as 3 in the example. After completion of the braiding, the elastomer core 2

088 / B wrapped over the entire surface with metal wires 3, which form a continuous metal casing. The fiber 1 is therefore suitable for improving the heat transfer through the compression cushion thus formed, either the fibers 1 themselves in the compression cushion forming a metal part, either in addition to the longitudinal metal fibers or the longitudinal fibers being formed in the same way as the fiber L

Figure 2 shows a fiber 4 that can be used as a substitute or in combination with the fiber 1 of Figure 1 in the press cushion. It also has an elastomeric core 5 of silicone elastomer, which - not shown here - encircles the central fiber that can be formed. in the same way as the fiber of Figure 1.

A metal wire 6 is wound around the elastomer core 5 in such a way that it wraps the elastomer core 5 over the entire surface and thus forms a continuous metal casing. It is expedient for another metal wire to be wrapped around the metal wire 6 in the opposite direction so that a two-layer metal braid is formed. This ensures that a complete braid of the elastomer core 5 is guaranteed during bending.

Claims (16)

Pressing cushion for use in laminating presses with intersecting fiber fabric (4), using fibers (4) having a fiber core (5), which at least on the outside consists of a rubber-elastic material and is wrapped with at least one metal wire (6), characterized in that the metal wire (6) or the metal wire (6) or the metal wire (6); metal wires (3), is wound up or wound. they are wound around the fibers of the soul (5). Press cushion for use in laminating presses with intersecting fiber fabric (1), using fibers (1) having a fiber core (2), which at least on the outside consists of a rubber-elastic material and is wrapped with at least one a metal wire (3), characterized in that metal wires (3) are entwined around the core fibers (2). Press cushion according to claim 1 or 2, characterized in that the core fibers (2, 5) are completely covered by a metal wire or a metal wire. metal wires (3, 6). Press cushion according to one of Claims 1 to 3, characterized in that the core fibers are completely wrapped in at least two layers of metal wires. A press pad according to any one of claims 1 to 4, characterized in that the rubber-elastic material has a Shore-A hardness of 60 to 75. A press pad according to any one of claims 1 to 5, characterized in that the rubber-elastic material is a silicone elastomer. A press pad according to any one of claims 1 to 6, characterized in that the rubber-elastic material is foamed and has a density of 0.3 to 0.5 g / cm ³ . 31,088 / B / J Pressing cushion according to one of Claims 1 to 7, characterized in that the metal or the metal of the cushion is in accordance with the invention. the metal wires (3, 6) are copper or strength modified copper alloys. Compression cushion according to one of claims 1 to 8, characterized in that the fibers (1,4) have a diameter of at least 1 mm, preferably of at least 1.5 mm. Pressing cushion according to any one of claims 1 to 9, characterized in that the core fibers (2, 5) consist of a central fiber and encircling the sheath of a rubber-elastic material. A press pad according to claim 10, characterized in that the central fiber is formed as a plastic monofilament or multifilament. A press cushion according to claim 10, characterized in that the central fiber is formed as a metal wire, a metal strand or a metal fiber, in the case of metal wires intertwined around the core fibers. Press cushion according to any one of claims 1 to 12, characterized in that the interwoven metal wires (3) are partially S-shaped and partly Z-shaped. A press pad according to claim 13, characterized in that the metal wires are alternately braided in S-shape and Z-shape. A press cushion according to any one of claims 1 to 14, characterized in that metal fibers are used in which the central fiber of metal or plastic is wrapped with at least one metal wire. A compaction pillow according to any one of claims 1 to 15, characterized in that metal fibers are used in which metal wires are entangled around the core metal or plastic core.