FI98903C - Method for providing a load consisting of rollers of compressible material - Google Patents

Abstract

The subject of the invention is a method for making a load of cylinders of compressible materials, consisting in constituting modules, each formed by a layer of cylinders, in superposing a plurality of modules in a stack, in compressing the assembly of modules thus superposed, in stopping the compression in order to let the assembly relax, optionally in turning the assembly in order to place the cylinders upright, then in placing ties to keep the stack to the dimensions obtained. The invention also relates to the device for implementing this method. <IMAGE>

Description

5 98903

Method for making a load on rolls of compressible material - Method for the production of a roll of compressible material

The present invention relates to the manufacture of compressible materials, in particular insulating felts of glass wool or other mineral wool, and more particularly to the realization of less space-consuming pallet-friendly loads which facilitate the transport and storage of such products.

Lightweight fibrous insulating materials are usually packaged in a compressed state in the form of rolls which are sealed with unit-15 covers of the paper web type or shields of substantially polyethylene-based plastic material which are heat-shrunk. In order to reduce transport costs, these rolls are usually assembled, especially on the packing and unloading stage, and to facilitate storage, separately on pallets. In practice, the size of these should be suitable for the dimensions of means of transport, trucks or, in most cases, railway wagons. The latter also limit the total height of the load placed on the pallet, which must thus ultimately follow a rather tight span to accommodate a small number of rollers.

'25: '. In addition to the load being surrounded by rigid panels that form protective cages that ensure the determination of the volume divided into rollers - the solution of which is the natural • · *. *. There is a significant increase in the cost of the load - the rollers must be • · * · * · 30 on the other hand, so that the weight of the rollers forming the upper * · «'· * layers acts perpendicular to the radial compressive force used to make the roll. . Under these conditions, increasing the number of rolls per load to be placed on the pallet does not appear possible other than by reducing the diameter of the rolls by 35, i.e. by increasing the compression ratio during wrapping. However, this solution, which is already very widely used, is limited by the compressive yield point of the material; it must be borne in mind that the insulating capacity of a fibrous material is directly proportional to its thickness, so that any weakening of this level is thus unacceptable.

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Similarly, European patent application EP-A-275 473 discloses enclosing a group of five or nine rolls with a plastic film, covering the group thus insulated with a suction device which removes part of the air trapped between the turns of felt 5 and between the rolls. The removal of this amount of air then makes it possible to approximate the rollers while the load is finally retained in this reduced state by means of a circumferential wrap. However, such a method requires relatively complex equipment and in particular requires a second step of setting the envelope in the event that the batches have to be superimposed.

It is an object of the invention to provide a new solution for compacting roll loads of compressible material, in particular insulating fibrous material, or, of course, the same, increasing the number of rolls per load, while maintaining the quality of the material and in particular avoiding permanent deformations. even after a relatively long storage period, 20 for example a few months.

To this end, a method is provided comprising the following steps of assembling modules, each consisting of a layer of rollers placed in contact with each other, and stacking a plurality of modules, the rolls being horizontal. (See EP-A-220 980, which shows the state of the art.) The method according to the invention is characterized by additional steps in which a set of overlapping stacks is compressed by stacking modules.

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In the direction in which the compression is brought to a thickness corresponding to a compression ratio of the material to be compressed which is greater than the compression ratio corresponding to its elastic limit, the compression is terminated and said units are released and set in place. bonds to maintain the module stack 35 in the proportions provided. Before putting these ties in place, the stack can also be rotated 90 ° to make the rollers upright.

The temporary vertical compression can be very considerable and in any case correspond to a compression ratio well above the compression yield of the 3 98903 material, which material is already, as should be remembered, very strongly compressed in the roll forming step. For example, the compression may temporarily result in a load height of 50% to Θ0% 5 of the original height, with the duration of the compression step adjusted appropriately and the shorter the higher the temporary compression used.

As soon as the pressing is interrupted, the rollers regain part 10 of their original thickness, but only part. However, the increase in thickness does not manifest itself as damage to the compressible material. Inspection of the rollers shows that this reduction in the height of the load is not in fact due to a new compression of the load but to a rearrangement of the rollers, 15 which initially cylindrical rollers begin to resemble more parallelepipeds, which shape produces a denser stack. Surprisingly, it appears that this shape of the parallelepiped does not in any way impair the quality of the final product and that the product opened from the package shows no signs of processing.

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The stack must remain in the proportions obtained after it has been released; for this purpose, a binding machine can be used, which places two or three bonds, for example of plastic. Another possibility is to wrap in a plastic, pullable film, in which case the load is protected against bad weather. weather and thus possible to store it outdoors.

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*, 'It is preferable to limit the roll stack to three layers, but • · · \ 30 several loads - at least two - can be placed on top of each other • «* ·' · before the bonding step, while naturally

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ensure that the axes of the rollers are in line to avoid that the weight of the upper layers does not damage the lower layers.

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Vertical compression should not be completely replaced by the displacement of the outer rollers of each layer, so these rollers must be secured so that compression does not displace them to the side. For this reason, the roll stack can be pre-bonded before pressing. Another solution is to surround the whole of the rolls forming the layer, which has the advantage that pre-packed modules consisting of, for example, 4-6 rolls are obtained, which can then be delivered for sale in batches. In this case 5, the end faces of the rolls are not supported during compression, provided, however, that the material used to belt the modules formed by the rollers has a certain flexibility, which in practice does not cause any problems. In addition, such belts of thermoplastic material can add to the interconnection of the modules 10 before they are turned, this reinforcement being implemented by heating the belts - for example by hot air blowing - during the stack release phase. The interconnection of the modules can also be increased by means of adhesive or adhesive tapes.

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The invention also relates to a device suitable for carrying out the method according to the invention, comprising a stacking station for roll layers, a vertical pressing station, possibly a position where the stack is rotated 90 °, a binding station 20 and a conveyor for moving the stack from one position to another.

The pressing station can be formed, for example, by a pressing plate suspended by a pulley above a belt conveyor, the function of which is to bring in and remove the stacks. Such a pressing station can be added to an existing one. but pack 1 india without disturbing it. In another alternative embodiment of the invention, the pressing station «· · * • · * · *. forms a hydraulic table which lifts the load and presses the «« f, 2 against its flat, fixed pressing table, thus replacing the conveyor.

In a very particularly preferred embodiment of the invention, the pressing plate is not quite flat, but comprises: * v a thickness in its central region, which forms a kind of upper mold 35 which increases the pressing force locally and the name to its own vertical from the rollers in the middle of the module. This allows a good * ··· 'alignment of the rollers of the same module, which, when placed from the belt, • tend to settle to an arc to some extent, with the middle roller 98903 5 forming a limestone.

Other details and preferred features of the invention will be explained below with reference to the accompanying Figure 1, which shows a perspective diagram of the compression station of the device according to the invention.

As already mentioned, the invention is applied to rolls and in particular to glass-bottomed felt rolls. These rolls 10 are realized, for example, by following the methods described in patent applications FR-A-2 553 744, EP-A-238 393 or EP-A-294 320 or any other method suitable for producing a winding with the most uniform compression possible over the entire length of the rolled felt strip. , so that threads ai-15 are obtained, all of which have the same thickness, including the first turns, which form the center of the roll and also the most brittle part thereof.

If appropriate precautions are taken when winding the felt 20 over itself, the glass sheet-based felt can withstand compression ratios of 4 or more, meaning that the thickness of the rolled strip is less than a quarter of the original thickness, which is again reached when the roll is unwound. In general, all 25 rolls are made to have identical diameters, regardless of the thickness of the strip, so that the dimensions as well as the weight j ·. remain substantially constant, which facilitates their packaging. In the following and for the sake of clarity, reference will be made to a roll type with a diameter of 400 to 410 mm and a length of 1200 mm, but it is clear that the method according to the invention can be applied to rolls of different diameters. Likewise, the number of rollers per module or per load or half of a load can, of course, be varied and applied to each individual case without departing from the scope of the invention.

In the first step, the rolls, each wrapped in heat-shrinkable polyethylene film or simpler kraft paper, are combined into five-piece modules, 6 98903 each module being belted. In the module, the rollers are long side by side in the same line. This belt is tensioned and thus deforms the rollers, which change from cylindrical to ovoid, with their largest dimension being 5 vertically. Typically, the height of the module is on the order of 445 mm and the length 1495 to 1500 mm, indicating low compression at the sides.

In the second step, the modules are superimposed as shown in Figure 1, which schematically shows a stack of three five-roll modules 1 secured by a shrink feed 2. As this belt presses the rolls lightly, the upper baselines of the rolls of a particular module - or the lower baselines -15 are, in fact, not exactly in the same plane, but delimit an arcuate curve, with one roller — mostly the middle — acting as a limestone. This phenomenon can be disturbing in the case that the more the parallelepiped-shaped loads are, the less they require ti-20 laa. As will be discussed below, a suitable form of press plate according to the invention offers an excellent opportunity to remedy this problem.

The height of the stack of three modules thus formed is thus 1330 to 1340 mm. It is conveyed, for example, by a belt conveyor 3 to a pressing station. This pressing station is protected by lateral gratings 4, the sole purpose of which is to ensure the safety of the packing line personnel who may have to pass over the belt conveyor. The essential element is a compression plate 5, which here consists of a reinforced concrete block weighing 3 tonnes, supported by a metal φ · ♦ V * structure consisting of commercially available profiles.

The pressing plate 5 is moved by a pulley 6 capable of moving the plate slowly or rapidly (for example at a speed of the order of 1 m / min during pressing and 4 m / min during the entry and rise stages of the plate). The pulley 6 is supported by a metal frame 7, which further serves to guide the press plate 5, which press plate is provided with a guide system which slides on the vertical supports of the frame, and which further supports the belt conveyor 3 to compensate for deformation due to its pressing forces.

The assembly also comprises a safety device which locks the pressure plate 5 in the upper position, this device consisting of, for example, rods 8 on which the projections 9 connected to the pressure plate 5 will rest, thus preventing it from lowering. When the system is in operation, these rods 8 are separated from each other by a rotary rod 10, which in this case is controlled manually, but which can also be switched on automatically by sensors which indicate the presence of a load.

The press plate 5 comprises a central thickness opposite the central rollers of the stack, which forms a kind of upper mold which makes it possible to level the various modules.

When the stack of three modules is in place in the pressing position, the pressing plate 5 is lowered and presses the stack so that its height will be, for example, between 950 and 1000 mm. Such vertical compression is partially offset by an increase in the length of the modules, which is 30-50 mm, as the case may be. Such compression of the rolls, which comes in addition to the compression of the felt during wrapping, is in no way acceptable in itself and would inevitably cause · * «*. significant damage to the felt and loss of thickness recovery if maintained for a relatively long period of time. However, it has been found that such damage does not occur if this period is sufficiently short.

• I ·! .. * In practice and always in the above case, this • · · "· '* compression is maintained for a time of not less than 15 seconds and not more than 40 seconds and is most preferably between 20 and 30 • · seconds. even more, for example by means of a heavier press plate, it is advantageous to shorten the duration of this press slightly, otherwise it can be extended, although this solution is not generally considered to be advantageous, as it leads to a slowing down of the manufacturing times.

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When this pressing step is completed, and without attempting to hold the load in such a pressing state by means of some type of bandage or belt, the pressing plate 5 is raised to the upper position and the stack of three modules is thus released. In this case, the loosening of the stack caused by the elasticity of the material is observed, which stack is stabilized at a height between 1200 and 1230 mm, i.e. an increase of more than 100 mm with respect to the original height is achieved. Examination of the rollers further shows that they do not fully retract their original cylindrical shape, but tend to have a parallelepiped-shaped shape with a more square cross-section, with the increase in height thereby substantially reducing the free, unfilled space between the rollers. In addition, the ovoid deformation of the rollers has practically disappeared and the stack is tighter.

The stack is then removed and rotated 90 ° with a suitable swivel so that the rollers are upright. Another similar stack is then assembled and both stacks are placed on top of the pallet, for example by means of a gripper-type gripping device, while ensuring that the rollers in the upper row are exactly in line with the lower rollers. The condition of the load thus assembled is finally maintained by surrounding it with a pullable film 25 of plastic material. This circumferential wrapper makes it possible to compensate for any slackening of the loads by compressing them. however, they no longer (the expansion of the rollers is due to loosening and not • expansion, i.e. the air removed between the rollers during compression no longer penetrates the stack during the expansion phase).

• »« * • h (* · 1 m · · "· '* Without changing the final compression ratio of the product, the invention makes it possible to substantially improve the degree of filling of means of transport (railway wagons or lorries), since 35 loads take up less space.

It should be noted that the invention is by no means limited to the embodiment shown, and that various alternative embodiments may be selected: for example, the modules may be non-adhesive but supported by a binder. Likewise, the stack can be supported before compression with a wrapper, making the belts of the modules unnecessary. Finally, the movable compression plate can be replaced by a fixed plate 5 connected to the hydraulic table.

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Claims (9)

1. A method for obtaining a load consisting of rolls of compressible material, comprising the following steps: each other in a horizontal position, characterized by the following steps: - the whole of the pd placed modules is compressed in the stacking direction of the modules, the compression giving the whole a thickness whose height corresponds to the compression ratio of the compressible material which is higher than a compression ratio's relative to its , - the compression is terminated and the whole is relaxed; 25. bindings are mounted to maintain the dimensions of the module stack. f ♦ The method according to claim 1, characterized in that before the bindings are assembled, the whole is turned so that the rollers:? * 30 is set vertically. • ·· ♦ «« • ♦ · «. Method according to any one of claims 1 or 2, characterized in that the compression is maintained for a time not less than 15 seconds and not more than 40 seconds. 12 9690i Method according to any of claims 1-3, characterized in that two piles of rollers are placed on each other before the bonds are mounted. 5. A method according to any of claims 1-4, characterized in that the modules are surrounded by tape. Method according to any of claims 1-5, characterized in that the module stack is bonded to bonding by heating the strips. 7. A method according to any of claims 1-4, characterized in that the module stack is bonded together. 15 Method according to any of claims 1-4, characterized in that the module stack is redesigned. Method according to any one of claims 1-8, characterized in that the compression is strongest in the middle. • «1 · · *« «•« • · · • · «• · · · · · · · •« «· · · · m