DE1923699A1 - Press roll - Google Patents

Description

B e s c h r e i b u n g 's is known to be gases and / or liquids from flat structures - for example from sheets or sheets of paper, cardboard or Textiles - largely to be withdrawn by the fact that these fabrics are in one or several phases of their production are subjected to pressing processes.

From the large number of continuous or used in practice discontinuous processes are the treatments with nip rollers as examples, Suction rolls, screen presses and shrink screen presses mentioned.

It is also known to use pressure rollers that are effective at their Have grooves on the surface. The grooves improve the discharge of the squeezed out Medium from the press zone. In contrast to the smooth press roll, where the squeezed out Medium emerge from the press zone essentially only in the direction of travel of the pressed web can, the medium flows here mainly from the press zone perpendicular to the web in the grooves. The degree of withdrawal is therefore much higher than with smooth rollers. Examples of groove presses are the Hi-I and Venta-Nip presses.

The grooving presses, despite their favorable properties, have the following (te disadvantages known per se: When using metal rollers, the flat structures highly stressed. They are also used, for example, in the production of raw cardboard or paper the felts supporting the sheet quickly wore out. Plastic-coated rollers however, they wear themselves out quickly and often have to be removed and reworked will. - In the formation of the groove cross-section, one is finally on the Limited possibilities due to machining processes - e.g. on the Lathe - are bid. Complicated groove cross-sections require, as far as they are concerned There are high costs to be created at all. In addition, simple groove cross-sections are a burden, e.g. the usual rectangular Cross-sections 1 mm deep and 0> 5 mm width, only with special aids - e.g. high pressure spray pipes - to remove impurities keep clear.

The invention was therefore based on the object of pressing; rolling without the to produce mentioned disadvantages.

According to the teaching of the present invention, gases are withdrawn and / or liquids from sheet materials used a press roll, which thereby is characterized in that a wire or band spirally so on the roll shell is wound that on the roll shell and at least over the Arbeltsbreite at least one winding layer rests on the roller.

Press rolls according to the teachings of the invention are advantageous designed so that the wire or tape is made of organic and / or inorganic Materials, preferably made of metal and / or plastic. - The selection the materials for the wire or the tape is determined in the special case by the properties the gases and / or liquids determined that are withdrawn from the fabrics should, through the properties of the fabric itself and through the temperature, which prevails during the pressing process.

It is obvious to use nylon wires or tapes, for example. In this case, a particularly strong winding is obtained when the finished winding is used Immerse the roller in water at 80 to 900 C for a few minutes. The one entering Shrinkage of the nylon increases the tension of the winding.

Press rolls according to the teaching of the invention are advantageously designed so that the individual turns of the wire or tape are applied close to one another that the roll shell of the winding layer or layers is almost completely is covered. - In other cases, however, it is advantageous that according to the invention the single ones Windings are applied so that between them there is a noticeable gap.

By selecting the wire or strip cross-section and / or the distance The turns can be used to determine the shape and size of the groove formed between the turns will change to a large extent. The groove can in this way meet the working conditions be adjusted. A suitable shape of the groove offers, for example, the possibility of Counter clogging of the groove. So tends, among other things, in the creation of flat structures with relatively short fibers - for example in the manufacture of base cardboard Fabric to set itself apart in narrow cross-sections. In this case, it turned out to be It has been shown to be expedient to design the groove in such a way that it faces the surface structure Opening is larger than that in the bottom of the groove. For example, wire from circular cross-section used wrapped tightly together. - Should be radial inwards the roller are drained, the groove is designed in such a way that it is narrower on the outside than on the roll shell. For example, a band of trapezoidal Cross-section applied at a distance from turn to turn. - Flushes in both cases the listed water removes the cardboard material from which it expands in the direction of flow Cross-section and in this way avoids soiling of the groove.

Press rolls according to the teaching of the invention are used for suction ills roller interior designed with particular advantage that when using a Hole suction roll the holes of the roll shell in the axial direction through grooves with one another are connected. In this way it is achieved that the pressed media in the narrow groove only have to cover short distances. The pressure needs for keeping up Sufficient flow velocities are kept low in this way.

It has proven to be useful to apply the wrapping to rollers, which are coated with an elastic plastic, in order to be effective To give the roller surface additional flexibility. - The same property can be achieved if, in the case of uncovered rolls, a profiled roll is used for wrapping Belt is used, with that area of the belt that is the effective roller surface forms, with elevations and depressions running in the longitudinal direction of the belt is provided. From the bottom of the depressions to the one resting on the roll shell, smooth surface, the tape has such a thickness that it gives the desired flexibility results.

When using certain wire cross-sections, e.g. with round wire, i.st Experience has shown that it is advantageous to place a spiral on the surface of the unwound roller work in a running groove that connects the wire to be wound with part of his Absorbs cross-section. This makes winding easier and the wire in better fixed in its position.

Particular advantages of the press roll according to the invention are that wear only occurs on the wrapping and da.J the wrapping is quick and easy - also on the roller that has not been removed - can be replaced. - With regeneration can adjust the properties of the roller by selecting suitable wires or tapes in wide limits can be changed and adapted to the requirements. This applies to the material properties the effective roll surface with regard to wear and tear on the roll and / or on the preteii fabric and finally for the temperatures during the pressing process.

Further advantages arise when there is a slight mobility the winding is given in relation to the roll shell. Because of the movements Experience has shown that one of the windings tends towards one another, e.g. one wound with nylon round wire Roller for self-cleaning of their grooves. - Further, e.g. for pre-rollers with experience has shown that initial unevenness is caused by wrapping made of nylon round wire reduced in line pressure after a short period of operation. This makes it possible to use constant camber conditions under Line prints to master with a steady course. In one application, round nylon wire was used of 2 mm in diameter, a camber dimension of 0.3 mm in the roller diameter is achieved.

Press rolls according to the teaching of the invention can instead of the previously known rollers in all known pressing processes for the extraction of gases and / or Liquids from sheet materials are used. In particular, it is possible to wind existing press rolls in the machine without dismantling them. The withdrawal effect is significantly improved in comparison with smooth press rolls; so became in one Application the dry content of a sheet of raw cardboard with a smooth press roll of approx. 40 to approx. 45% and with a roller wound with N5ylon round wire from approx 40- C, 3 brought to around 50%.

The training vqn press rolls according to the teaching of the invention is through the attached sketches explained by way of example.

Figure 1 shows a press roll according to the invention in longitudinal section, at that of the roll shell (1) with wire of circular cross-section (2) without Z, hissing spaces wound ist0 Figure 2 is similar to the figure in Figure 1 with the difference that the wire (c) is wound onto the roll shell (1) with gaps and that in this way a different shape and size of the groove is achieved.

In Figure 3 there is wire of a square cross-section (3) on the roll shell (1) applied; the groove has a rectangular cross-sectional shape.

FIG. 4 shows a press roll according to the invention in longitudinal section, their jacket (1) with a wire of special profiling (4) with spaces is occupied. The wire has an approximately trapezoidal cross-section, with one of the short ones Trapezoidal sides rests on the roll shell and the long one facing the sheet Trpezse.ite is arched. The arched training favors the pressure gradient in the direction of the groove.

The groove itself widens towards the roll shell, so that when it is radial Suction inwards; the risk of clogging is countered.

FIG. 5 shows a press roll according to the invention in longitudinal and cross-section for suction inwards, the roller shell (5) with radial bores (6) and axial grooves (7) is provided, with zede axial grooves through the center points of all on each one Bores lying on the surface line runs.

In Figure 6, a press roll according to the invention is shown, whose Sheath (1) is covered with protiled tape (8) instead of wire.

Claims (5)

Claims 1. Press roll for gas and / or liquid extraction from heaps, d a d u r c h e k e n n n z e i c h n e t that a wire or Tape is wound spirally so that on the roll shell and at least at least one winding layer rests over the working width of the roller. 2. Pre roll according to claim 1, d a d u r c h g e k e n nz e i c h n e t that the wire or strip is made of organic and / or inorganic materials, preferably made of metal andfor plastic. 3. Press roll according to claim 1 or 2, d a d u r c h g e k e n n -z e i c h n e t that the individual turns of the wire or ribbon are close to one another be applied so that the roll shell of the winding layer or layers almost is completely covered. 4. Press roll according to claim de-r 2. d a d u r 4 h g e k e n n -z e i c h n e t that the individual turns are applied so that between them there is a considerable gap. 5. Press roll according to As claim 1 or one of the following, d a d u r c It is not noted that the holes are made when using a hole suction roller of the roll shell are connected to one another in the axial direction by grooves. and press roll according to claim 1 or one of the following, d a d u r c h e k e k e n n n n n e i n e t that a profiled tape is used for wrapping the area of the belt that forms the effective roller surface, provided with elevations and depressions running in the longitudinal direction of the tape is.