EP0551228B1 - Method and apparatus for compressing a roll of fibre mattress - Google Patents

Abstract

The baler consists of two endless flexible belts (17, 18), each covering approximately a half of the bale being rolled, which is made from a strip (19) of a compressed fibrous material. The completed roll is discharged from the baler in the same direction as that in which the strip (19) is introduced. The strip of fibrous material (19) is compressed by passing it between two compression units (5, 6) at the inlet side of the baler, e.g. in the form of endless belts which compress the strip without slipping. In a variant of the design the fibrous strip can be held in its compressed state by a metal pressure plate, and as each bale is completed it can be wrapped in a layer of a film material.

Description

The invention relates to techniques for compressing and then winding fibrous mats to allow their wrapping and conditioning up to their place of use. Flexible fibrous mattresses, in particular those made of glass wool or rock wool intended for insulation, are most often wound on themselves very tightly to prevent them from occupying too much volume important during their transport. The higher the compression ratio of the fibrous mat, the cheaper the transport and storage.

In general, the production lines operate continuously and deliver mattresses of uninterrupted length. These are cut to form rolls whose width and length correspond to the needs of the user. On the production lines of insulating wool mattresses there are winders whose operation is more or less automated.

To perform their functions, these machines must have a number of basic characteristics. They must compress the woolen mattresses as much as possible and this in the same way over their entire length but they must also avoid damaging the fiber and the binder which constitute the insulating mattress.

Furthermore, it is important that all of the operations be carried out at a sufficient speed to be compatible with the running speed of the mattress. This point is particularly important for modern lines whose production capacity is often desired. To do this, we multiply the glass fiber or rock production units upstream, all of these units supplying successively the same mattress, the running speed of which depends, all other things being equal, on the number of machines upstream. From this point of view, it is particularly important that the rewinders avoid downtime. The ideal rewinder would be a machine that would roll up the mattress at the speed at which it runs on the production line without any dead time between the end of a first mattress and the start of the next mattress. Thus the winding speed would be minimal and would avoid all the disadvantages such as: premature wear, breakdown ...

One mission that the invention sets itself is precisely to provide a winder whose downtime is reduced to a minimum.

To reduce transport costs, very high compression ratios must be achieved without degrading the fibrous mat. An object of the invention is to provide fibrous mattresses wound on themselves with high compression ratios and which find all their original characteristics on decompression.

An object of the invention is also to provide a winder which in no way degrades the fibers and the binder of the fibrous mat during compression.

The rolls of mineral fiber mattresses which it is possible to obtain with the rewinders of the prior art are limited in the case of specific masses of 8 to 10 kg / m³, at compression rates of less than 7/1 if the compression is carried out in a single operation and at rates of between 6 and 8/1 with the methods comprising two mechanical steps or a mechanical step and a vacuum step.

There are two types of existing winders: either the elements between which the winding takes place are essentially planar elements, or else the winding takes place inside a substantially circular cavity.

A winder of the first type is described for example in patent EP 294 290. It comprises two flat conveyor belts associated to form a dihedral which is in permanently tangent to the fibrous roller in formation. The compression of the fibrous mattress is exerted by a movable roller whose position and speed of rotation obey precise laws. This type of winder has two types of drawbacks. First of all, the pressure is exerted on the fibrous roller in formation only in well-defined places. Between these compression zones, the fibrous mat relaxes to be compressed again a little further. This alternation of pressure / depression on the fibers can cause them to break and moreover the binder which associates the fibers with one another undergoes fatigue which can cause its deterioration in places. The second drawback of this type of winder lies in their discontinuous operation. At the end of the winding operation of a first fibrous roller, the pressure roller must be spread so as to allow the ejection of the fibrous roller and it is only after its return that the following priming operation of the winding of a new fibrous roll can take place.

A second type of winder has been developed. He uses to press on the fibrous roller either a free mat or two groups of belts which form a sort of circular cavity around the roller.

This technique is described for example in US Pat. No. 4,602,471. The fibrous mattress transported by a belt conveyor is forced before entering the reel to pass under a plate which compresses it during transport on the last belt conveyor which precedes the reel itself. The compressed mattress then enters the loop formed by the free mat held by two fixed rollers. This system has the advantage of avoiding having the compression / decompression phases of the previous type of winder. This avoids breakage of fibers and fatigue of the binder. However, there remains however a degradation of the fibers, it is due to the fact that before entering the circular cavity the fibrous mattress transported by the flat belt conveyor exerts a continuous friction on the upper plate during its compression. Regardless of whether he is strong energy consumer this strongt may cause deterioration of the fibers of the mineral wool or glass wool mattress. A second difficulty with this type of winder lies in the fact that at the end of the winding operation it is necessary to separate the two rollers which close the cavity in order to allow the evacuation of the new fibrous roll formed. The time required is thus added to the duration of the winding itself.

Document US Pat. No. 4,034,928 describes a winding machine intended to wind a flexible film on itself by temporarily using a central mandrel. The roll in formation is rotated by two groups of belts which each enclose substantially half the circumference of the roll. In addition to the fact that this machine which wraps incompressible films does not deal with the problems of compression and decompression of a compressed mattress, it does not eliminate idle times since the entry of the film and the exit of the finished roll take place on the same side. of the machine. In addition, the use of a central mandrel on which the film adheres by vacuum and which would be incompatible with a porous material solves the problem of initiating the winding in a manner that cannot be applied to fibrous mattresses.

The invention relates to a roll of compressed insulating mattress based on mineral fibers and a specific mass at the origin of 8 to 10 kg / m³, the compression ratio of which is at least 8.5 to 1.

The subject of the invention is therefore a winder for winding a flexible band around itself and in which the roller in formation is rotated by two flexible means which each enclose a part of the circumference of the roller in formation and which are guided and driven by appropriate means in order to adapt to the magnification of said roller in formation (see US-A-4,034,928). According to the invention, the flexible strip is a fibrous mattress compressed by compression means before winding, and the flexible means are carpets which encircle one substantially half the circumference of the forming roller and the other a substantial part of the remaining half.

The subject of the invention is also the rolls of compressed insulating mattresses based on mineral fibers obtained by this type of winder, and in particular having a compression ratio of at least 8.5 to 1.

In the winder according to the invention, the evacuation of the roll of the compressed mattress is carried out in the same direction as the introduction of the compressed fibrous mattress.

Furthermore, the compressed fibrous mattress is obtained by compression without sliding of the fibrous mat between pressing members which are preferably between two conveyor belts.

In a variant of the winding machine of the invention, a device such as a metal plate keeps the fibrous mat compressed between its exit from the pressing members and its contact with the preceding turn of the roll in formation.

Preferably, the compressed mattress is introduced substantially tangentially to the periphery of the roller being formed.

In the different variants of the invention during winding, at least three of the four rollers which guide the two belts are tangent to a cylinder whose director has substantially the shape of a spiral corresponding to the theoretical envelope of the compressed roller. at the same time.

According to the preferred embodiment of the invention, two of the four preceding rollers, located downstream of the machine are replaced - at the moment when they release the finished roll - by two new rollers whose progression is carried out in the same direction as the downstream rollers. Preferably, in this case, the four rollers are associated two by two with rotating systems of the carousel type which support them.

The fibrous mattress roll of the invention with high compression ratio allows significant savings to be made during the transport and storage of the insulating blankets.

The technique of the invention makes it possible to exercise weighting the winding at a constant pressure both in time and in space, thus avoiding the back and forth compression and depression which degrade the fibers and cause fatigue of the binder. The fact of passing the device according to the invention through the fibrous roller rather than exerting a back and forth movement also makes it possible to reduce downtime very significantly.

An important advantage also lies in the fact that thanks to the device of the invention, it proceeds directly to the winding of the compressed roller in its film which keeps it in place, thus avoiding any recovery, any release of the pressure while limiting downtime.

• La figure 1 représente le dispositif de l'invention avant le début de l'enroulement du matelas fibreux sur lui-même,
• La figure 2 représente l'enroulement en cours et,
• La figure 3 l'éjection du rouleau comprimé de l'invention à la fin de l'opération d'enroulement.
• La figure 4 et la figure 5 présentent une variante de l'enrouleuse de l'invention.

The figures and the description which follow will make it possible to understand the operation of the invention as well as its advantages.

• FIG. 1 represents the device of the invention before the beginning of the winding of the fibrous mattress on itself,
• FIG. 2 represents the winding in progress and,
• Figure 3 ejection of the compressed roll of the invention at the end of the winding operation.
• Figure 4 and Figure 5 show a variant of the winder of the invention.

In Figure 1 we see the essential elements of the device of the invention. We see in 1 a first conveyor belt whose conformation varies throughout the winding operation. It is the same for the second conveyor belt 2. Before the beginning of the winding, the two conveyors follow a rectilinear path against the current 3. To facilitate the understanding of the device, the support rollers have been shown with circles around their axes. treadmills, the position of which does not change during the entire winding operation. On the other hand the rollers whose axes are represented by crosses in broken lines have their position which changes during the duration of the winding of the fibrous mat. We see in 4 the fibrous mat from the production line which is compressed between two planes. The first consisting of a part 5 of the treadmill 1, the second consisting of a part 6 of another treadmill 7. The two plane elements 5 and 6 move at substantially the same speed which is the speed of exit of the mattress fibrous 4 of the production line. This part of the device therefore makes it possible to avoid any relative movement between the fibrous mattress and therefore the fibers of the fibrous mattress on the one hand and the carpets which compress them, on the other. This avoids everything friction which would risk damaging said fibers. In one embodiment of the invention, the flat part 5 of the treadmill 1 is actually supported by a second treadmill 8, the upper part of which supports the straight part 5 of the treadmill over its entire length. It is advantageous to use this conveyor belt 8 not only to support the treadmill 1 but also to train it in its translational movement. The roller 9 is therefore advantageously used to drive both the conveyor belt 8 and the conveyor belt 1. The rotational movement of this roller 9 has a constant speed during winding. As for the conveyor belt 2, it is driven by one of its support rollers upstream of the cavity, for example the roller 10. Its speed is also constant during the winding. Furthermore, the tension of the conveyor belts 1 and 2 is provided respectively by the roller 11 and by the roller 12, the position of which is controlled by the central computer at all times. The cavity in which the compressed fibrous mat is rolled up is defined by five rollers and two conveyor belt elements. Among the two rollers are fixed: the roller 9 which has already been discussed and the 13 which guides the treadmill 2. During the entire winding, the rollers 14 and 15 respective supports of the treadmills 1 and 2 move in two paths parallel rectilinear so as to release a length of mat respectively 17 for the mat 1 and 18 for the mat 2 which will serve to form the circular wall of the cavity where the compressed mattress will be rolled up. The small movable roller 16 exerts a particular function at the start of the operation. When the end of a new section of compressed mattress 19 enters the cavity the roller 16 occupies a position which allows the end of the mattress 19 to penetrate very far into the cavity. This position is determined by the thickness of the mattress to be rolled up. The purpose of the roller 16 is to close the cavity at the start of winding and to allow the formation of the first turn. For a felt of a given type, the position of the roller 16 is fixed. At this moment, the rollers 14 and 15 begin to move to the left of the figure in the direction of the roller 10 and its twin roller 20. This movement is also managed by the computer so that the four rollers 9, 14, 15 and 13 occupy the theoretical position at the periphery of the compressed fibrous mattress, that is to say that they are tangent to a cylinder with a spiral director.

We can follow the winding operation on itself of the compressed fibrous mat in Figure 2. By comparing with Figure 1 we see that the movable rollers 14 and 15 have moved to the left and that the roller 16 is in a position such with respect to the roller 9 that it maintains the pressure on the mattress which has just been compressed by the two rectilinear parts 5 and 6 of the pressing belts. Here sections 17 and 18 of the conveyor belts 1 and 2 cover the periphery of the roller of the compressed mattress under tension. It can be seen in FIG. 2 that the compressed roller is kept under pressure over practically its entire periphery by all of the four rollers and the portions 17, 18 of belts which surround it. At each instant, the computer calculates the theoretical dimension to be given to the cylinder with spiral director which constitutes the periphery of the compressed roller. This dimension depends on the one hand on the compression coefficient which it was decided to apply to the mattress, therefore finally on its thickness in the compressed state and on the other hand on the length of mattress already rolled up. The rollers 9 and 13 being fixed, it is the position of the rollers 14 and 15 which defines the cylinder in question, the length of the curved walls 17 and 18 of the cavity being defined by the position of the tensioning rollers 11 and 12, determined it - even by computer.

The packaging of the compressed roll is carried out simultaneously with the winding of the last turn of compressed mattress. The same materials as usual are used for packaging, such as kraft paper, plastic films, for example polyethylene. The strips of film intended to package the products are pre-cut and pre-glued.

In Figure 2 we see them waiting at 21 on the distributor 22 which will cause them to advance at the desired time so that they come into contact with the fibrous mat before its compression. Gluing was carried out at both ends, on the upper face. As soon as the film comes into contact with the mattress, it adheres to it and is drawn around the compressed roller. The film is so long that it extends beyond the back of the end of the mattress. Its glued side can thus pass through all of the conveyor belts and rollers without adhering to it and the film ends up sticking to itself. It can thus be seen that the packaging operation is carried out almost completely in masked time, that is to say that it does not last longer than the winding of the last turn.

The next step is to eject the wrapped roll. It is shown in Figure 3 where we see a general movement of the carpet 1 driven by the roller 20 which was hitherto stationary and which this time moves down to free the passage to the compressed and packaged roller 23 which occupies the position 24 on the conveyor 25 which discharges it. As soon as the roller 23 has left the reel, the belt 1 driven by the roller 20 comes back to the position it occupied at the start of the operation in FIG. 1. The rollers 14 and 15 also come in their original position and the operation can start again immediately. It is thus seen that the dead time which separates the end of the winding of a first roll and the start of the winding of the next roll is very reduced since in the device represented in FIGS. 1, 2 and 3 it suffices that roller 20 moves away from roller 10 and then returns to its original position while rollers 14 and 15 also make the return journey. This can be done in fractions of a second.

FIG. 4 and FIG. 5 show a variant of the invention which uses two carousels, respectively 26 and 27, to obtain the movements of the support rollers for the belts 1 and 2. Each of these carousels has two cheeks between which are fixed. rollers which will in turn support the belts 1 and 2. Each of the carousels' cheeks has three radial arms located at 120 ° from each other. At the ends of these arms are fixed levers which in turn carry at their ends the rollers which support the belts 1 and 2. The levers deviate more or less from the axis of the carousels by means of jacks. Only one of the three rollers on each carousel is active at any given time. In the figure these are the rollers 28 and 29. They are supported respectively by the levers 30 and 31, actuated by the jacks 32 and 33, and themselves supported by the radial arms 34 and 35. The function and the movement of the rollers 28 and 29 is exactly the same as that of the rollers 14 and 15 of FIG. 1. The two carousels 26 and 27 are driven in a synchronous movement but their speed is not constant. It is such that, as before, the rollers 9, 13, 28 and 29 are in a position such that the belts 1, 2 constitute the theoretical figure which defines the compression of the fibrous mattress wound on itself. If the rollers are of small diameter, they can be all four tangent to this theoretical figure otherwise, as in the figure, only three are. When the constitution of the compressed roller is complete, as well as its packaging, the jacks 32 and 33 are actuated quickly so as to bring the rollers 28 and 29 closer to the axes of the carousels which allows the rolls of finished compressed mattresses to be ejected. At this point it is the turn of the following rollers on the carousels, namely 36 and 37, to come into action. They are quickly brought closer to the rollers 9 and 13 so as to create a new cavity in which the compressed fibrous mat will be able to start its winding. It can be seen that in this variant of the winder of the invention, any dead time between the end of one operation and the start of the next operation is eliminated. In the configuration of FIGS. 4 and 5 the driving rollers are the roller 9 for the belt 1, the roller 39 for the conveyor belt 7, and the roller 38 for the belt 2. The speed of these three rollers is constant, as for the rotational speed of the two carousels and the position of the two jacks 32, 33 and so on that the position of the tension rollers 11 and 12 is determined by the central computer of the device.

The variant of FIGS. 4 and 5 therefore has the advantage of allowing two pairs of rollers 36 and 37 to succeed immediately without dead time the rollers 28 and 29 which have just escaped from the other side.

There is shown in the same figures, at 40, a device which makes it possible to maintain the pressure on the compressed mattress between the place where it leaves the upper presser belt 7 and the place where contact with the previous turn 41 is established. It is for example a metal plate supported by a flange which passes between the rollers 39 and 13.

To test the advantages which the invention makes it possible to compare its operation with that of a reel for killing of patent EP 294 290. The tests were carried out with a mattress with a width of 1 m 20 driven to the maximum speed of the rewinder of the prior art, that is to say 150 m per minute with a mattress with a thickness of 300 mm and a specific mass of 10 kg / m³ which also corresponded to the maximum possible with the rewinder of the prior art, that is to say a compression ratio of 6/1. The finished roll had a diameter of 500 mm. The operating characteristics of the winder according to the invention were the same as those of the winder of the prior art. prior art invention winding time 3 sec 3 sec packing time 1.5 sec 0.5 sec ejection time 2.5 sec 1.5 sec waiting time 1.5 sec 1 sec Total 8.5 sec 6 sec

The table presents the results obtained. The most spectacular progression concerns time packaging, this is due to the fact that the reel of the invention performs it in masked time, in other words the packaging is carried out at the same time as the winding of the last turn of the compressed mattress.

The overall results therefore show a gain of around 25% in the time required for compression and winding of a given compressed roller. This advantage over time is accompanied by an improvement in quality since the compression of the mattress takes place without relative sliding between it and the pressing members as was the case in document US Pat. No. 4,602,471. improvement is even more noticeable if we compare the winder of the invention compared to that where the winding was carried out between two planes materialized by transprteuse bands. Indeed, with this system it is found that the fibers are subjected to repeated compression / decompression actions which cause the fibers to break and the binder to fatigue.

The compressed roller of the invention, with for the first time, compression ratios higher than 10/1 obtained directly on the rewinder without deterioration of the mattress which regains its thickness and its original qualities present compared to the rollers of the prior art the advantage of savings on packaging, transport and storage.

Furthermore, the reduced downtime of the machine, object of the invention, makes it possible to reduce the necessary ratio between line speed and winding speed. This ratio was so far from 2 to 2.5 and it decreases to 1.3-1.5 on the new machine. This allows either to wind a given product for a given line speed at a lower winding speed and therefore further improve the quality of the winding, or to wind a given product at a winding speed ( which can reach 200 m / min) higher than the maximum speed allowed so far (150 m / min). This saves on investment.

Claims (14)

1. Winding machine for winding about itself a flexible strip (19) in which the roll being formed is entrained in rotation by two flexible means (17, 18), each of which hugs one part of the circumference of the roll being formed and which are guided and entrained by suitable means in order to adapt themselves to the enlargement of the said roll being formed, characterised in that the flexible strip (19) is a fibrous mat compressed by compression means (5, 6) before winding; and in that the flexible means (17, 18) are belts, one of which hugs substantially half of the circumference of the roll being formed, and the other of which hugs a substantial part of the remaining half.
2. Winding machine according to Claim 1, characterised in that the removal of the roll of compressed material (23) is performed in the same direction as the introduction of the compressed fibrous mat (19) into the winding machine by a belt (1) entrained by a roller (20) which displaces itself downwards to open the passage to the compressed roll.
3. Winding machine according to Claim 2, characterised in that the compressed fibrous mat (19) is obtained by compression of the fibrous mat (4) without sliding, between compression means, in particular between conveyor belts (5, 6).
4. Winding machine according to Claim 3, characterised in that a device such as a metallic plate (40) keeps the fibrous mat (19) compressed between the mat leaving the compression means (5, 6) and the mat being brought into contact with the preceding turn (41) of the roll being formed.
5. Winding machine according to any one of the preceding claims, characterised in that the compressed mat (19) is introduced substantially tangentially to the periphery of the roll (42) being formed.
6. Winding machine according to any one of the preceding claims, characterised in that the belts (17, 18) which hug the roll being formed are guided by four rollers, two of which (9, 13) are fixed, and two of which (14, 15; 28, 29) are movable.
7. Winding machine according to Claim 6, characterised in that a fifth roller (16) facilitates the start of the winding and cooperates in this by occupying a position permitting the end of the flexible strip (19) to penetrate very far forward into the cavity formed by the belts (17, 18).
8. Winding device according to Claim 6 or 7, characterised in that, at a given instant, at least three of the four rollers are tangents to a cylinder of which the directrix is substantially in the form of a spiral corresponding to the theoretical envelope of the compressed roll at the same instant.
9. Winding machine according to any one of the preceding claims, characterised in that a packaging film is rolled simultaneously with the last turn of the roll of compressed mat by means of a distributor.
10. Winding machine according to Claim 9, characterised in that the length of the packaging film is greater than that of the development of the last turn of the roll of the compressed mat and in that it is coated with glue on its internal face at both ends.
11. Winding machine according to Claim 7, characterised in that the movable rollers (28, 29, 36, 37) are associated, two by two, with rotation systems of the carrousel type which support them.
12. Winding machine according to Claim 7 or Claim 11, characterised in that at the end of the winding, when the two downstream movable rollers (28) release the roll of compressed mat (19), two new movable rollers (36, 37) are brought into position immediately; and in that the progression thereof is performed in the same direction as that of the downstream rollers.
13. Winding device according to any one of Claims 2 to 10, characterised in that the entrainment of one of the belts (1) is performed by a conveyor belt (8) which supports it.
14. Roll of mineral-fibre based compressed insulating mat obtained by the winding according to any one of the preceding claims, having a specific original mass of from 8 to 10 kg/m³ and suitable for recovering its qualities after decompression, characterised in that the compression rate thereof is at least 8.5 to 1.

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