IE60164B1 - Preparation of bundles of fibrous heat insulants - Google Patents

Abstract

1. Process for packaging compressible fibrous insulating products (5) in which : the insulating products (5) are introduced into a compressing apparatus (11) in a predetermined number and in a regular stack, a film (16) enclosing this stack, compression is carried out in the direction of the stack, the film (16) is sealed around the stack in order to obtain a wrapped modular element, compression is relaxed, a plurality of modular elements are stacked to make up a group of modules, characterised in that sealing takes place by glueing or welding the film (16) onto itself around the compressed stack, the reaction of the products at the time of relaxation then the film (16) forming the wrapping and the modules are adjusted in the group of modules in such a way that the two adjacent module elements of the group of modules are in contact by the faces of the parallel module elements in the direction of stacking within the modules.

Description

The invention relates to the packaging of compressible fibrous insulating products.

The problem posed by these fibrous insulating products are well known. They are products which are very bulky for limited mass and the storing and transportation of which are relatively costly above all having regard to their value.

Quite early on, one solution was envisaged whereby these problems might be limited. It consisted of maintaining *10 the products in the compressed state from the time they were packaged until they were used. With the methods proposed, it is necessary to take account of the relative fragility of the product. The deformations brought about during compression must not alter the capacity to resume the initial volume when the packaging is removed.

The insulating properties of these products depend indeed upon this resumption of thickness.

For these reasons, the packaging methods proposed hitherto entail maximum precautions. One of these precautions consists in particular in carrying out compression under fully controlled conditions of deformation. To this end, the insulating felts are, for example, cut into panels which are superimposed at the rate of 3 to 20 then compressed in an enclosure, the movable wall of which, carrying out the compression, is applied over the entire face of the panel which is at the end of the stack. Orientation of compression and the deformation brought about so develop regularly within the product to avoid any deterioration thereof.

It has likewise been proposed to modify this method and to break down compression into a plurality of stages as in European Patent Application EP-A-72 302.

Nevertheless, with regard to packaging, what is most important is that it is necessary to provide for the use of perfectly defined shapes and packaging materials which afford a certain rigidity in order to impart to the bundles made up from compressed products all the stability required both in the shaping and also subsequently during storage and transportation.

To these constraints must if necessary to added the need to use a moisture-proof packaging, the handling operations of which being carried out as simply as possible.

The aim of the invention is to provide a packaging technique which more satisfactorily meets these requirements while furthermore offering greater facility of adaptation to the various products in question, reduced cost, and the possibility of dividing up the bundles when they are used.

Furthermore the Invention also sets out to provide a packaging which is capable of being used on the basis of covered modular elements, whatever the nature of the covering may be.

It appears that the form of packaging for insulating fibrous products currently used comprise at least the placing in position of a heat-shrinkable wrapping. In most cases, this wrapping is that which covers the bundle which has been prepared. In this case, its role is normally two-fold.

It contributes to cohesion of the bundle and in particular protects it against moisture when it is not stored in a sheltered place. Patent Application EP 119 032 proposes sealing preferably by ultra-sound, protective envelopes for cushion-type compressible products but this technique is only proposed to obtain a primary wrapping without associating it to the subsequent production of bundles.

In the present embodiments of these bundles, the wrapping which it is desired to shrink onto it must not come in contact with a primary wrapping or covering which might adhere under operating conditions. For this reason, when such a contact is likely to take place, it is necessary to interpose separating elements. In this case, sheets of cardboard are frequently used which at the same time impart the rigidity properties required to maintain the product in the compressed state or to give it its precise form. Nevertheless, the use of these interposed forms is an important factor in the cost of packaging which, according to the invention, it is desired to eliminate.

Furthermore, for the user, all these packaging elements constitute extremely bulky waste products, the destruction of which may give rise to difficulties on the site where the products are used.

According to the invention, there is provided a process for packaging compressible fibrous insulating products in which: the insulating products are introduced into a compressing apparatus in a predetermined number and in a regular stack, a film enclosing this stack. compression is carried out in the direction of the stack. the film is sealed around the stack in order to obtain a wrapped module, compression is relaxed. a plurality of modular elements are stacked to make up a group of modules, characterised in that sealing takes place by gluing or welding the film onto itself around the compressed stack, the reaction of the products at the time of 5 relaxation then tightening the film forming the wrapping and the modules are adjusted in the group of modules in such a way that two adjacent modules of the group of modules are in contact by the faces of the parallel module elements in the direction of stacking within the modules.

The film is preferably stretched over the compressed products. The film is sealed and compression relaxed.

The bundle is made up fran .these elements wrapped in a film which is sufficiently strong to hold the products in the compressed state. In the bundle, the stacking of elements is carried out in such a way that the elements rest on one another with the faces of these elements which have not been subjected to a compression operation during wrapping. Finally, the various elements of the bundle, grouped together in several superimposed layers, are preferably wrapped in a drawable film.

With respect to the bundles known from Patent Application EP-A-72 032, the bundles according to the invention have the advantage that there are no rigid assembly means. In accordance with the invention, it is the reaction itself of the products which leads to sufficiently flat binding surface being obtained. Whereas according to EP-A-72 302 obtaining a flat surface and protection against inclement weather are two functions performed by different elements.

In the succession of operations thus defined, which produce a bundle, only the unitary or pre-grouped products can be the subject of packaging in a heat-shrunk film. All subsequent operations are carried out mechanically so that there is no risk of sticking between the various films or wrapping used during the course of the successive packaging stages.

For this reason, likewise according to the invention, there is no restriction as to the choice of materials which can be used for the first wrapping or covering of the fibrous product. It is possible indiscriminately to use kraft papers or plastic films, particularly PVC or polyethylene film.

In the packaging according to the invention, no stiffening element is required to make up the bundles.

In the prior techniques, the need to have recourse to these stiffening elements originated from the fact that final compression was carried out on large volume assemblies corresponding for example, to half the finished bundle.

Under these conditions, the deformations of these volumes under the effect of the reaction of the compressed products was such that they might compromise the stability of the bundle (and its availability for subsequent bundling).

For this reason, relatively rigorous retaining was necessary. In particular, stiffening elements (and protective elements) associated with very strong binders 3 ensured this. This is the method described in particular in French Patent Application No.2 460 862 and in addition No.2 491 889 thereto.

Furthermore, according to the invention, by orientating 15 the elements in the bundle so that the direction of compressions is in the plane of the superimposed layers, the limited deformations are at the periphery of the bundle and do not impede the regular stacking of these elements on one another.

In this way, a bundle is obtained with no other means of ♦ maintaining compression than the packaging or film enclosing these elements. The use of supplementary binders or protective and strengthening panels becomes superfluous.

This procedure does not eliminate the possibility of a succession of compression stages making is possible to achieve the high levels desired. Simply these compressions are carried out on smaller assemblies or even on the unitary or regrouped products prior to the wrapping which is carried out according to the invention.

Advantageously, the wrapped element or module is of such a size that at least two must be grouped together to constitute one and the same layer of a bundle, each bundle comprising at least two superimposed layers.

As cohesion is ensured at the level of each element defined hereinabove and these elements, owing to the small amount of deformation and orientation thereof, may be easily assembled, the cohesion of these elements in one end and the same bundle is advantageously achieved by means of a strap arrangement.

This operation consists in enclosing the bundle in a spirally wound strap, in such a way that the successive turns partially overlap.

Strapping is carried out in a conventional manner by using an extensible film. Subjecting it to a certain tension ensures its perfect adhesion to the wrapped product whatever the shape of this latter may be.

Also conventionally, according to the invention it is advantageous to use self-adhesive films. Superimposition of the turns is thus accompanied by a perfectly stable positioning of this wrapping which is capable of withstanding considerable stresses without movement. The layered structure of this wrapping furthermore, and even in the case of very thin films, imparts to it properties of mechanical strength which are quite remarkable.

The self-adhesive nature of the wrapping film likewise facilitates fixing of the start of the strip when it is applied to the bundle. The end is held in place by a gripper during the first few turns. Then, adhesion of the turns to one another is sufficient to hold the film in place.

Winding of the strip may follow a progression, taking into account the variable properties required according to the height of the bundle on which it is wound. It is possible to have a tighter pitch of the winding turns at those places where particular mechanical strength must be provided.

This is, for example, what must be particularly sought after in order to ensure firm adhesion of the various layers of the bundle against one another.

According to the invention, it is preferable to provide for a double strip arrangement. After a first winding from top to bottom or from bottom to top, a second winding is carried out in the opposite direction, without interruption.

Intersection of the ascending and descending turns imparts considerable stability in the wrapping formed in this way against mechanical stresses.

Advantageously, the strip wrapping may likewise serve to attach to the bundle a pallet facilitating its transport by conventional mechanical means such as fork lift trucks. To this end, for example, the bundle or more exactly the elements of which it will be constituted are placed on a pallet. When all the elements are collected together, winding of the wrapping strip commences.

This is applied over the entire height of the bundle including the pallet, enveloping this latter sufficiently for the strength of the film (or of the superimposed layers of film) to constitute an adeguate binder rendering the pallet rigid with the rest of the bundle.

The strip wrapping film may be subjected to a tension which varies according to its location on the wrapped bundle. In the case of the invention, it is thus possible to reduce the tension exerted on the corners of the bundle. Thus, compression of these corners is avoided, as is also an ovalisation of the bundle and any damages to the products which may result therefrom.

Strap wrapping may also be used to form a virtually weatherproof wrapping when the bundle has to be stored or transported without any other protection. In this case, at the top of the batch there will be placed a covering consisting for example of a plastic sheet which sufficiently overlaps the load for it to be folded down onto the side faces.

On the side faces, moisture-tightness is obtained at the junction between the turns by applying the winding strip in an ascending direction. Even if the adhesion of the turns on one another leaves any interstices through which water might penetrate the bundle, the fish scale arrangement prevents such penetration.

For the same reason, the top covering must cover the topmost turns. In an advantageous arrangement, the covering is maintained on the bundle by the wrapping strip itself. In practice, once the ascending strip has been wound onto the bundle, the covering is placed in position without breaking the film and winding is continued to cover the turned over edges of the covering.

When a complete double winding process is carried out, the covering is placed in position between the ascending winding and the descending winding.

To finish the protection of the bundle it is likewise possible to place at its base a protective sheet which is held in position by the wrapping film. The edges of this film are either lifted up onto the sides of the bundle or more simply, when the bundle is placed on a pallet, folded down over the edges of the pallet and wrapped up at the same time as this latter.

Other details concerning the invention and its implementation are described hereinafter, reference being made to the accompanying sheets of drawings, in which: Fig.l is a synoptical diagram of the packaging according to the invention, applied to rolls of 20 insulating felt; shows on a larger scale the stage where the elements constituting the bundle are formed, comprising wrapping under compression; Fig. 2 Fig. 3 Fig. 4 Fig.5, 6, Fig. 9 shows the stage where the bundle is formed by superimposition of two layers of elements; diagrammatically shows the stage in which the bundle is wrapped in the strip; 7, 8 are respectively similar to Figs.1, 2, 3 and 4 and relate to the packaging of flat insulating felt sheets; and is similar to Figs.2 and 6; it shows in detailed fashion and in halves, the two extreme positions of the operation of strip wrapping the modular elements.

The upper part of the diagram in Fig.l shows the formation of a roll of glass fibre insulating felt according to the conventional method as described, for example, in French Patent Application No.2 553 744.

The fibre felt 1 usually emanates directly from a production line.

Rolling up of the felt without damaging it is possible 20 when its volume mass prior to compression is not too high.

According to the initial volume mass, the rate of compression applicable is substantially different. In the compressed state, the rolled-up felts generally have a volume mass which is not greater than 65 kg/m2 * Conventionally, the rolled-up felts prior to compression do not have a volume mass greater than 30 kg/m2 . The more denser felts are preferably made up in the form of more or less compressible flat panels.

The felt 1 is rolled onto itself in the example illustrated between two conveyor belts 1, 3 and a roller 4. According to the method described in the aforesaid Patent Application, the compression of the felt in the P roll 5 is performed by a programmed movement of the roller 4.

According to the teachings of this Application, it is possible to obtain a roll which, while ensuring a high compression, does not alter the capacity of the felt to resume its thickness when it is used. For good quality felts of low volume mass, it is thus possible to produce rolls in which the rate of compression may be as much as 6, in other words in which the thickness of the felt is reduced to one-sixth of its volume in the non-compressed ‘ state. Λ Even if in the stage following packaging the felt is subjected to further compressions, it is preferable to impose as high a rate as possible right from this stage. It is indeed at this stage that the gain in volume is greatest.

Upon completion of winding of the felt upon itself, a 5 sheet 6 of paper or some plastics material envelopes the roll formed. This sheet, intended to maintain the roll 5 in the compressed condition which has been imposed upon it, is glued to itself in known manner, for example by a line of glue or by a heat-sealing process.

Advantageously used as a wrapping on each roll is a sheet of heat-shrinkable polymer, for example a sheet of polyethylene. By using a heat-shrinkable sheet of a width slightly greater than that of the roll, it is possible at least partly to protect the ends of the roll.

The ends of the wrapper are subjected to a heat treatment. The retraction which results therefrom does indeed fold back any parts of the sheet which overlap either side of the roll at the ends thereof. Thus these ends are protected against any damage which might emanate from subsequent handling.

Covered with its wrapper (if necessary shrunk on), the roll is then conveyed to an apparatus which makes it possible to combine a plurality of these rolls into one modular element which is intended to form the bundle.

The rolls are routed by automatic and conventional means to a stacker 7 (Fig.2). This stacker comprises means for controlling the intake 38 which, coupled with counting means not shown, make it possible to form batches of a specific number of rolls in the stacker.

To allow the handling of products of variable size and/or shape, the walls 9 of the stacker are preferably adjustable, for example by means of laterally disposed jacks.

In the same way, the space offered to the rolls is bounded in its length by a frontal abutment. This abutment can likewise be regulated according to the length of the rolls.

In the embodiment shown, the introduction of the rolls into the stacker is carried out by gravity. In other constructions, when the stacker is not vertical, it is possible to provide conventional loading means such as push members which are activated by jacks, the operation remaining substantially the same.

When the batch of rolls constituting the modular element is collected together, the trap or equivalent means 39 which held back the rolls opens and releases these latter, which pass into an apparatus 11 in which the module is wrapped in the securing strip.

This apparatus 11 is constituted by two vertical walls 12 which can be regulated like the walls 9 of the stacker.

Longitudinally the rolls are held in place by abutments, not shown.

The bottom end of this apparatus is closed by a moveable wall 48, the translatory movements of which are carried out by means such as a jack 14 or similar means.

The entrance to the apparatus 11 is opened and closed by means 45, 47 which may form an abutment capable of withstanding the compression stress imposed on the rolls .

The rollers 42, 43 over which these two films pass are caused to perform the same opening and closing movement as the abutment rollers 46, 47 in order to allow the rolls 5 of the felt to enter the apparatus 11.

An assembly for welding the two films is disposed immediately above the rolls, constituting an abutment.

Operation of the apparatus 11 in detail and more particularly with reference to Fig.9 is as follows.

The rolls or in Fig.9, the packages of parallelepiped shape carried for example on a belt conveyor 37 arrive flat and lengthwise at the entrance to the stacker 7.

The first package is carried over the stacker and slides onto two retractable arms 8 so that it comes to rest on the frontal abutment 36.

The presence of the package in contact with this abutment causes the arms 38 to open; guided between the lateral walls 9 regulated by jacks 35, the package falls by gravity onto the retractable arms 39 which form the bottom of the stacker.

The top arms 38 close immediately to receive the second package and the previously described cycle is reproduced until the number of packages programmed for formation of one module has been attained.

Once this condition is fulfilled, the bottom arms 39 of the stacker move aside and the assembly of packages contained in the stacker falls by gravity onto the wrapping film strip 16 stretched between the two gripper roller assemblies 40, 41 and, resting on the film guide rollers 42, 43. The guide rollers are integral with the assembly, not shown, which supports the welding bars 44, and two moveable stops comprising rollers 46, 47. According to its position this assembly releases or blocks the intake to the apparatus 11.

As the two abutments 46, 47 are moved aside laterally 5 (right-hand side of Fig.9), the batch of packages supported by the wrapping film is lowered into the apparatus 11.

The two gripper roller assemblies 40, 41 deliver the film 16 as the module is lowered between the adjustable walls 12 of the apparatus 11.

When the batch of packages comes to rest on the bottom of the apparatus 11, consisting for example of a belt conveyor 48, the level of which is adjustable according to the height of the packages forming the module prior to compression, the two top abutments 46, 47 close again (left-hand side of Fig.9) and the gripper rollers 40, 41 stop the unreeling of the wrapping film strip. At the same time, a fresh cycle to form the batch of packages is commenced in the stacker 7.

The walls 12 may give way slightly, the bottom of the apparatus moves vertically from the bottom upwards entrained by a mechanical chain system, not shown, controlled by a variable speed drive. This system may be replaced by a pneumatic or hydraulic jack 14.

The packages forming the module are then compressed « between the abutments 46, 47 and the conveyor 48.

Simultaneously, the excess film arising from compression 5 of the packages is recovered by the movement of tensioning members 49, 50 which move as shown in the left-hand part of Fig.9. The movement of the walls 12 away from each other during this operation facilitates displacement of the film along the module (in particular avoiding the formation of creases).

Once the height determined according to the compression to be obtained has been achieved, the conveyor 48 stops.

Aided by the gripper rollers 40, 41 and the abutment rollers 46, 47 the tensioning members 49, 50 continue to take up the excess film until a detecting system placed on the tensioning members 49, 50 (same length of film to be recovered for one and the same number of packages at the same compression rate) causes them to stop. The film is then held taut over the module.

The welding rods 44, 45 are closed again onto the two strands of film which are welded, the cut out by a cold cutting system. The securing strip has been applied.

The welding rods 44, 45 open and the tensioning members 49, 50 recover the residual slack in the film after the gripper rollers 40, 41 have moved away. These latter close again subsequently pending the arrival of the new package. The conveyor 48, on which the module enclosed in its wrapping now rests, is lowered again to its initial level in order to allow removal of the package to the stacking table.

Advantageously, the film 16 used for wrapping the modular 10 element extend over the major part of the packages.

Since the wrapping thus achieved bears over a large surface area, it has no tendency to penetrate the felt. There is no need therefore to provide rigid protective elements between these package wrapping means and the packages themselves, as is the case with prior art methods which employ a system of hooping using binders of small thickness. Preferably, the wrapping covers at least two-thirds of the length of the packages.

The film used is advantageously a polyethylene film, the thickness of which is between 40 and 100 micrometers.

When the modules are made up of rolls, the compression which is imposed varies according to the rate of compression at the rolling stage. It goes without saying that the higher the initial rate of compression, the less the deformation which can be imposed on the felts without altering their quality. However, even for very high rates of compression at the rolling stage, a certain deformation is possible in the forming of the module.

Generally, the reduction in volume owing to compression and wrapping of the module may be as little as 7% or less for products which are most compressed previously. For the others, compression may be higher but preferably ought not to exceed 20%.

In all cases, compression of the rolls comprises flaps in areas where they are in contact with one another.

This deformation provides the module with good stability so long as the number of rolls is not too great. Advantageously, the rolls should not exceed six in number and three or four are preferable.

The conventional sizes of rolls and those of the made up bundles control these numbers. The diameter of the rolls is ordinarily between 600 mm and 300 mm.

A typical example according to the invention corresponds 20 to the felts with a volume mass of 11.5 kg/m 3 at nominal thickness (that is to say guaranteed at the time of use) of 80 mm with a length of 9 m.

These felts are rolled up at a compression rate of 5.7 into rolls of about 400 mm diameter which are grouped together into modular elements comprising four rolls.

The wrapping film strip brings all four rolls to a height 5 of 1550 mm, in other words with less than 5% compression.

The stability in this case results from the friction which is exerted between the wrapping film and the wrapping of the rolls and also deformations in the rolls themselves.

The modular elements in the form shown in Fig.l are removed from the compression apparatus laterally and are taken up by a conveyor 21. They are carried flat to hoisting table 22 on which a plurality of modules are stacked by conventional automatic handling means.

Possibly, in order to render the modules nicely rigid inter se, an adhesive may be applied to their contacting faces. The adhesive is preferably located on the film used for wrapping each module.

Experience shows that stacking modules on their face is less stable in the forming of high bundles than that corresponding to rolls in the vertical position. In other words, rolls are less deformable under the effect of a loading in the direction of their length. To make up the bundles, a group of modules constituted as previously stated is then preferably disposed vertically by being tipped over.

The layer of modules which is thus constituted, in which the rolls are disposed vertically, is gripped by grippers 24 and deposited on a pallet 25. Depending on the height of this layer, that is to say the height of the rolls in a vertical position, two layers or more may be placed one upon another.

The vertical stability of the assembly made under these conditions is such that after formation of the bundle, as will be described hereinafter, it is possible to tie together a plurality of bundles on storage areas without any risk of collapse.

The pallet carrying the assembly of two superposed layers of modules passes onto a conventional type of strip fastening machine.

This machine shown diagrammatically at 23 comprises a 20 table 26 rotating about a vertical axis. Above the bundle the strip fastening machine comprises a vertically movable plate 33. This plate is applied to the top of the bundle which it holds in position during the operation.

To this end, the presser plate is capable of rotary movement about the same axis as that of the rotating table 26.

A frame supports a vertically movable carriage. The carriage carries an arm on which is a reel 27 and a system for predrawing and regulating tension which makes it possible to apply the film to the bundle at a given tension. As indicated previously, this tension may be variable in order, for example, to reduce compression at tbe comers of the bundle.

This arrangement is desirable when the elements constituting the bundle have angular edges. When, as in the embodiment shown, the comers of the bundle consist of the curved surfaces of rolls of felts, modulation of the film tension is of less interest.

The way this conventional type of machine functions makes it possible to place the end of the film onto the batch which is to be wrapped, rotation of the batch driven by the rotating table with a simultaneous progression of the carriage carrying the reel in a vertical direction.

The rate of progression can likewise be regulated, which makes it possible to vary the amount of overlap of the successive turns and in general the vertical movement may be programmed so that the progression occurs in a differentiated fashion according to the level of the batch in question. Thus, several turns may be made at the start of wrapping without the carriage carrying the reel moving, in order to ensure perfect starting of the strip and also satisfactory solidarity between the pallet and the first layer of modules. This type of machine likewise enables a covering to be placed automatically over the top of the batch.

The top covering is placed in position by an assembly disposed mo a movable carriage which is displaced on the horizontal rail. The assembly comprising the rail and the carriage which it supports is fixed on the vertical frame and may be regulated according to the height of the bundle to be covered.

The carriage supports a reel for the film constituting the top layer and means of cutting the film.

To place the top covering in position, the presser plate is raised (into the position shown by dotted lines in Figs.2 and 6), the carriage and its reel shown diagrammatically at 54 pass over the bundle unwinding the film which covers the top of the bundle.

Once the carriage has placed the film in position, this latter is cut and is completely detached from the assembly carried by the carriage so that it can be deposited on the bundle. The presser plate 33 is then lowered to grip the bundle again.

Advantageously, the top covering 55 is placed in position after the ascending application of wrapping strip and prior to the descending stage in order to hold it while making up a covering to protect the bundle against bad weather conditions.

If, on the other hand, a film has been placed on the pallet prior to this latter being loaded as previously stated, it constitutes a complete wrapping around the bundle.

As an example, in order to strip wrap an assembly such as described hereinabove, it is advantageous to use a polyethylene film 20 micrometers thick and 500 mm wide. Generally, the thickness of the film is chosen so that it lends itself to a certain extension. For a polyethylene film, for example, a thickness of between 15 and 25 micrometers should be chosen. This film is wound on in turns which overlap by half. A double ascending and descending winding process is carried out and on top of the bundle there is placed a covering layer of polyethylene which is 50 to 180 micrometers thick.

At all points, the bundle is therefore held securely by a rolled on wrapping, the total thickness of which is around 80 micrometers.

The assembly which is thus constituted is remarkably stable. It makes it possible for two bundles to be banded together without the addition of any interposed element.

Storage in the open air is possible since rain does not. penetrate the bundle.

The rigidity of the assembly is such that it can be transported on platform trucks by simple attachment of straps passed through the peg ladders.

For the user, the bundle of the type according to the invention offers the advantage that it can be subsequently broken down into layers and then into modules and then into rolls as needs dictate, the unused part of the bundle remaining in the form of a stable assembly.

Also noteworthy is the great flexibility of use of this type of bundling which makes it possible to assemble layers of different sizes according to the needs. It may be advantageous for example, to group together rolls of different heights in order, for example, to make up bundles having the most appropriate outline for the requirements of the transport media employed, whether for rail or road transport.

The second embodiment illustrated in the drawings is described hereinafter in a more brief fashion by virtue of the similarity of numerous stages of this packaging to that which has been described hereinabove.

In this example, the product is constituted by rectangular felt panels.

These panels are grouped together into unitary packages 15 in which they are compressed. Conventionally, 3 to 20 panels per package may be assembled together in one and the same wrapping. The number of panels is preferably such that the height of the panels (that is to say the sum of their thicknesses) in the compressed state is not greater than the width of these panels. This makes it possible to avoid deformations of the packages which would be prejudicial to formation of the modules and then of stable bundles.

The compression and the maintenance of this compression present particular problems for panels. In the case of rolls of felt, the roll itself absorbs the major part of the reaction to compression. The wrapping used only withstands limited forces. In packages of panels, the wrapping must withstand all the reaction to compression.

In addition to the increased strength which the wrapping would need to have if the rates of compression were increased, which might possibly be achieved by using thicker film, this increase would result in the packages becoming more oval in shape, which would adversely affect their subsequent grouping together in the form of a modular element.

Thus, by way of example, for panels with a volumetric mass of 14 kg/m 3 and with a nominal thickness of 75 mm, the rate of compression in the unitary packages does not normally exceed 2 and is most frequently around 1.5.

The compression and formation of unitary packages is carried out by conventional methods.

For example, the panels delivered by a stacker 28 in a predetermined number are compressed between two converging conveyors 20 and 30. Upon leaving this compression, they are wrapped in a sheet of shrinkable polymer while being maintained in the compressed state. The polymer wrapper is constituted by a double film emanating from reels 31. The double film previously welded, is entrained by the progression of the panels.

Once the assembly of panels 34 is fully engaged on conveyor means 56, the two sheets are folded back onto the rear face of the assembly and are welded at the end. The sheets are welded to one another according to two very closely situated parallel lines. The sheets are cut between the two weld lines. Once the package has been made up in this way, the wrapping is shrunk at the ends by the heating.

Thus wrapped, the packages are directed as previously to a stacker 7 and an apparatus 11 in order to prepare a modular element 32 (Fig.6). The same print is used for rolls and for packages of panels if necessary by modifying the dimensions by means of the adjustable lateral walls and the longitudinal stops.

At this stage of packaging, the main difference arises from the fact that it is advantageous in the formation of the module to carry out a substantial additional compression of tbe panels.

The problem of the resistance of the package wrapping to the reaction of the felts arises again in the preparation of modular elements. The tremendous amount of compression imposed must now be supported by the wrapping film. It is, however, relatively easy to satisfy this condition since it is possible to choose the nature of the film without any other constraint. In particular, it is not necessary to have a shrinkable film. The film chosen is chosen first and foremost for its strength. It is thus easily possible to attain compression ratios of as much as 3 or more.

Experience has demonstrated that it is preferable to limit the number of panels per package. Breaking down the assembly constituting the modular element into smaller and more numerous packages is an element in the stability of the module.

It is also found that in the constituted module, deformations of the ovalisation type disappear for all the packages except for the two packages located at the ends. Limiting the number of panels in each package and particularly in those placed at the ends therefore makes it possible to restrict the disadvantageous effects of those deformations to a smaller number of panels.

Of course, in order suitably to maintain the various packages used to make up the modular element, it is preferable to proceed in such a way that the wrapping covers all or almost all the length of the panels.

As for modules consisting of rolls, the wrapping of the modules is not subjected to any heat shrinking process. Compression is obtained by the workings of the apparatus 11. By means of this apparatus it is possible to impose a compression which is slightly greater than that which it is desired to establish in the module being made up and then, after having welded the film which is to form the wrapping, the pressure exerted by the movable wall 13 is relaxed and the wrapped packages stretch the film which maintains the compression at an adeguate level.

The reaction of the panels is exerted only according to the direction at right-angles to the surface of the panels. The modules constituted are automatically placed on a stacker 22, the panels resting on the face of the module corresponding to the thickness of the panels.

This face is virtually flat. Deformations under the effect of pressure do not affect it. This permits the satisfactory superposition of modules as indicated in Fig.7.

In the case illustrated, the modules are constituted from 3 unitary packages. In other embodiments, the modules consist of 4 or 5 packages.

These modules are stacked on a pallet by gripper arms of a specific number in order to constitute a bundle of dimensions appropriate to storage and transport. The made up bundle is then wrapped in strip material according to the same conditions as described previously (Fig.8).

The strip wrapping is carried out under the same conditions as for the rolls.

Bundles of considerable height (2,500 mm or more) are 10 obtained which are very stable to the extent that they can be banded together without difficulty. As previously, these bundles may be exposed to inclement weather conditions. They stand up well to automatic handling procedures and can be transported without being covered.

Claims (10)

1. Process for packaging compressible fibrous insulating products in which: the insulating products are introduced into a 5 compressing apparatus in a predetermined number and in a regular stack, a film enclosing this stack. compression is carried out in the direction of the stack. the film is sealed around the stack in order to 10 obtain a wrapped module, compression is relaxed. a plurality of modular elements are stacked to make up a group of modules, characterised in that sealing takes place by gluing or welding the film onto itself around the compressed stack, 15 the reaction of the products at the time of relaxation then tightening the film forming the wrapping and the modules are adjusted in the group of modules in such a way that two adjacent modules of the group of modules are in contact by the faces 20 of the parallel module elements in the direction of stacking within the modules.

2. Packaging process according to Claim 1 in which the film surrounding the stack is arranged at the entrance of the compressing apparatus and is entrained by the products themselves as they 5 progress, this film being stretched when the stack is compressed prior to its being secured by adhesion.

3. Packaging process according to Claim 1 or 2 in which the film enclosing the stack is constituted by two 10 distinct sheets which are adhered or heat-welded at their ends previously, these sheets emanating from two reels situated on either side of the path of the products entering the compression apparatus, after which compression is 15 carried out and each sheet is stretched over the stack, the sheets are adhered to each other by thermo-welding on either side of a cutting line ensuring on the one hand detachment of the wrapped stack and on the other the formation of the adhered 20 double sheet ready to receive a fresh stack of products.

4. Packaging process according to one of the preceding claims, in which the stacked modules forming the modular groups are gathered together by means of an extendable film which is strip wrapped around the periphery of these superimposed modules.

5. Packaging process according to Claim 4, in which the 5 modules are arranged on a pallet which is likewise incorporated into the strip wrapping so that the pallet becomes integral with the group of modules and thus forms a bundle.

6. Packaging process according to Claim 4 or Claim 5 in 10 which the bundle is covered at its top by a covering which overlaps the edges of the bundle maintained in position by rolls of strip film applied over the edges of the top covering which are folded down over the sides. 15

7. Packaging process according to Claim 6 in which the bundle receives a double ascending and descending layer of wrapping between the windings corresponding to these two wrapping stages.

8. Packaging process according to Claim 5 and either of 20 Claims 6 or 7, in which a protective film is placed on the pallet and overlaps the edges thereof where it is held fast by the wrapping strip.

9. Packaging process according to any one of Claims 1 to 3, in which the film encircling the products is a polyethylene film of a thickness comprised between 40 and 100 micrometers. 5 10. Packaging process according to any one of Claims 4 to 8, in which the wrapping film strip is a polyethylene strip of 17 to 25 micrometers. 11· A process for packaging compressible fibrous insulating products according to Claim 1, substantially

10. As described with reference to Figs. 1 to 4 and 9 or Figs. 5 to 8 and 9 of the accompanying drawings.