EP1040910B1 - Press pad - Google Patents

Abstract

The cushion (1) with a textile thread system (2, 3) for laminating presses either contains a looped-thread fabric (2) or is entirely made of such a fabric.

Description

The invention relates to a press pad for use in Laminating presses with a textile thread system, with meshed Threads.

The production of layer materials, for example decorative coated chipboard, done in laminating presses, which as low or high pressure floor presses or Short-cycle presses can be designed. So the pressure of the press plates over the entire surface and evenly on the material to be pressed is transferred between the material to be pressed and the Press plates press pads inserted. The press pads must high pressures and also those occurring in such presses Can withstand temperatures and they have to be in be able to withstand the heat emanating from the press plates to transfer quickly and without large losses to the pressed material. It is also desirable to use a press pad to process pressed material of different formats in succession.

Press pads are known which are made from a textile thread system exist in the form of a fabric or contain it. DE-B-23 19 593 discloses a press pad, the The basis of a metal screen mesh is that made up of a matrix is enclosed in a silicone elastomer. The press pad according to DE-A-23 38 749 has a glass fiber fabric on which single or all threads with one Plastic, for example a silicone elastomer, impregnated or coated. These threads are consequently elastic and form the padding of the press pad. The corresponding can be found in DE-A-26 50 642. In EP-A-0 493 630 a press pad is made from a textile fabric is proposed, in which the fabric is made of aromatic polyamide threads and metal threads is. DE-U-295 18 204 discloses a press pad, in which a portion of the threads has a silicone elastomer and another portion formed as a metal wire can be. DE-U-94 18 984.6 describes a press pad, where the threads are made of different materials, especially of rubber, silicone elastomer or metal as well Combination of these may exist. Finally are in DE-U-297 21 495 and DE-U-297 21 494 press pad revealed from a fabric in which the individual threads are woven and trained in a special way.

In the generic EP-A-0 290 653 is a press pad disclosed with a textile thread system in which the thread system of individual longitudinal threads and individual Cross threads exist. The threads running in one direction have a soul thread that also consists of several Threads can be composed of one stitch thread is enveloped. The stitch threads of neighboring Individual threads are not directly connected to one another, but rather coupled over the cross threads that stitch the stitches of the Pass through stitch threads. The disadvantage here is the lack Stability in the direction of the cross threads.

In the known press pads, the range of variation is for a requirements-based design of the press pad in terms of elongation, elasticity, structural strength and limited thermal conductivity so that not always a optimal result regarding these properties can be achieved is. The invention is therefore based on the object to design a press pad so that a wider Range of possible variations for the interpretation of the Press cushion especially with regard to the aforementioned properties given is.

This object is achieved in that the thread system is a knitted fabric with one another over the surface has or consists of meshed threads, at least essentially a knitted fabric or Knitted fabrics, in particular a warp knitted fabric. Such Knitwear can be made in various basic weaves, for example fringe, leotard, cloth, satin, velvet and Atlas create, with the different basic ties can also be combined with each other. Hereby and by the amount of threads in the thread system by changing the needle pitch and the stitch density can expand the properties of the press cushion Areas are set according to requirements, especially with regard to elongation, structural strength, pressure elasticity and thermal conductivity.

In an embodiment of the invention it is provided that the thread system has additional threads that the stitches of the Assert knitwear. This is an additional one Possibility to influence the properties of the Press pad given. The additional threads can extend in the wale or in the direction of the course. Also an oblique course in which the additional Crossing threads across several rows of stitches is possible.

According to a further feature of the invention, that the thread system has thermal conductors made of metal exist or contain metal. Here come as metals or metal alloys, in particular aluminum, bronze, Stainless steel, copper or brass in question. The thermal conductors can also be used as plastic threads, for example made of aramid or polyimide, with a share of metal fibers or threads can be formed. The thermal conductors should alternate with threads in any order, whose thermal conductivity is lower and the other Take over functions. The change of these threads can both in the direction of the stitches and in the direction of the wales happen.

The invention further provides that the thread system has elastic padding threads, the press pad Give pressure elasticity. These can deal with the above-described thermal conductors in the direction of the course and / or alternate wale direction. By selection the course and the amount of such cushioning threads the pressure elasticity adapted to the respective requirements become. The cushion threads can be both part the knitwear itself, as well as partially or completely form the additional threads.

The cushion threads can be made of a rubber-elastic material, such as silicone elastomer, fluororubber or rubber. It can be rubbery Material is a metal in powder form or as short fibers included to increase the thermal conductivity of the upholstery threads improve. Upholstery threads are also possible, each have a soul thread that is of an elastic rubber Thread jacket is surrounded. The soul thread can from metal strands or plastic threads from e.g. Aramids, Polyimide, PPS or PEEK or combinations thereof. It can be used as a monofilament, multifilament, twine, spun yarn, braided strand, cord, ribbon or the like and combinations thereof. The thermal conductivity will be improved if at least one Part of the cushion thread is surrounded by metal wire, for example by wrapping, stranding or braiding. The thickness of the cushion thread should be chosen in this way that the usual pressures in the laminating presses i.e. under pressure, the upholstery thread has the same thickness as the metal thermal conductors. This ensures that the thread surfaces during of the pressing process all lie in one plane, whereby maximum contact surface and thus more even Pressure and an optimization of the heat conduction result.

In a further embodiment of the invention, that the thread system is included in a rubber-elastic matrix is, this matrix also made of silicone elastomer or fluorosilicone elastomer or other rubber materials can exist. To improve thermal conductivity the matrix should also have metal particles Contained in the form of powders or short fibers.

Finally, it is provided according to the invention that Press padding has edge thickening to ensure even To ensure contact pressure over the entire surface. The edge thickening can, for example, by local Increase in the needle pitch and thus the stitch density become.

Figur 1

eine Draufsicht auf einen Ausschnitt eines Preßpolsters aus einem Kettengewirke mit zusätzlichen Fäden;

Figur 2

eine Draufsicht auf einen Ausschnitt eines anderen Preßpolsters aus einem Kettengewirke;

Figur 3

die Seitenansicht eines Polsterfadens und

Figur 4

einen Querschnitt durch den Polsterfaden gemäß Figur 3.

In the drawing, the invention is illustrated in more detail using exemplary embodiments. Show it:

Figure 1

a plan view of a section of a press pad from a warp knitted fabric with additional threads;

Figure 2

a plan view of a section of another press pad from a warp knitted fabric;

Figure 3

the side view of an upholstery thread and

Figure 4

3 shows a cross section through the upholstery thread according to FIG. 3.

The press pad 1 shown in Figure 1 consists of a Thread system in the form of a warp knitted fabric 2 with additional Upholstery threads, designated 3 by way of example. The warp knitted fabric 2 forms rows of stitches - by way of example designated 4 -, with 4 in each course Upholstery thread 3 the stitches - designated 5 by way of example - enforced.

The warp-knitted fabric 2 consists of thermal conductors, namely in this case from copper threads. The cushion threads 3 are designed as silicone elastomer monofilaments. Instead of such Silicone elastomer monofilaments can also be used in the upholstery threads 3 and 4 and further described below Be used. The one made of copper threads Warp knitted fabrics 2 ensure good heat transfer from surface to surface while the cushion threads 3 for the conformability to the pressed material and Ensure the required elasticity of the press plate.

The press pad 6 shown in Figure 2 consists of a Warp knit 7. Change in warp knit 7 each have a heat conducting thread 8 and a cushion thread 9 (filled in black) in the course and stitch direction from. The thermal filaments 8 are also here formed as copper threads, while the upholstery threads 9 Display silicone elastomer monofilaments. Your functions are the same as for the press pad 1 according to the figure 1, i.e. the thermal conductors 8 ensure a good one Heat transfer between the two surfaces of the press pad 6, while the cushion threads 9 the pressure elasticity guarantee.

A special cushion thread 10 is shown in FIGS. 3 and 4 shown. It has a wire strand 11 as a soul thread made of copper by a thread jacket 12 from a Silicone elastomer is surrounded. The thread jacket 12 is on on the outside with copper wires - exemplary designated with 13 - braided. This gives the Upholstery thread 10 in addition to its elasticity in addition high thermal conductivity. When using such cushioning threads 10 in the press pad 6 should be ensured be that the upholstery thread 10 under pressure has the same thickness as the thermal filaments 8, so that the thread surfaces both the thermal filaments 8 and the Upholstery threads 10 all in one during the pressing process Lay level and thus a maximum contact surface and an even pressure is achieved.

Claims (12)

1. Press pad (1, 6) for use in laminating presses with a textile thread system (2, 3, 5; 7, 8, 9) having interlooped threads (5; 8, 9), characterised in that the thread system (2, 3, 5; 7, 8, 9) has a knitted fabric (2, 7) with threads (5; 8, 9) interlooped with each other over the surface, or consists thereof.
2. Press pad according to Claim 1, characterised in that the thread system has additional threads (3) interspersed in the mesh (5) of the knitted fabric (2).
3. Press pad according to Claim 1 or 2, characterised in that the thread system (2, 3, 7) has heat conducting threads (8, 10) composed of metal or containing metal.
4. Press pad according to Claim 3, characterised in that the heat conducting threads (8) alternate with threads (9) of lower conductivity.
5. Press pad according to one of the claims 1 to 4, characterised in that the thread system (2, 7) has padding threads (3, 9, 10) with thickness elasticity.
6. Press pad according to Claim 5, characterised in that the padding threads (10) each have a core thread (11) surrounded by a rubber elastic thread coat (12).
7. Press pad according to Claim 6, characterised in that the thread coat (12) consists of a silicone elastomer or fluorosilicone.
8. Press pad according to one of the claims 5 to 7, characterised in that at least one part of the padding thread (10) is surrounded by metal wire (13).
9. Press pad according to one of the claims 1 to 8, characterised in that the thread system is set into a rubber elastic matrix.
10. Press pad according to Claim 9, characterised in that the matrix consists of silicone elastomer or fluorosilicone elastomer.
11. Press pad according to Claim 10, characterised in that the matrix contains metal particles.
12. Press pad according to one of the claims 1 to 11, characterised in that the press pad has edge thickenings.

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