FR2467692A1 - Hot roll lamination of plastics films and metallic or other cords - to make reinforced corrugated packaging boards for mfr. of board structures and characteristics - Google Patents

Abstract

Various forms of reinforced sheet are made by laminating >=1 array of metallic cords with >=2 layers of plastic film passing around a drum and through >=1 roll nip. The superimposed layers are heated and opt. cooled to bond the interfaces and them corrugated prior to having a flat sheet laminated to one or both faces of the corrugated sheet. Used for mfr. of packaging materials involving thermoplastic (polyolefin, polyamide, polyester) or thermosetting (modified phenolic) films and opt. also involving non-metallic filaments or mesh and/or a layer of impact absorbent (cellular) (polyurethane) material to make strong, impermeable wrappers, containers or package linings.

Description

 The present invention relates to plates or sheets of reinforced plastic, flat or corrugated, and a new method and apparatus for manufacturing them. It also relates to the stratification of these plastic materials reinforced with other elastic or padding materials which are particularly suitable, among other applications, for the packaging of articles and products for transport.

More specifically, the first object of this invention is a new and improved corrugated material formed from plastic sheets and highly rigid metal wires as reinforcement elements, a material which is not only impermeable to moisture but which can also be made impermeable. to gases, and which does not get damaged and does not lose its solidity even if it is permanently subjected to humidity. Depending on the intended use, the reinforcing elements may be bare or, on the contrary, covered with a plastic material, and they are preferably longitudinal and transverse elements spaced from one another to give good mechanical resistance to the final material. , depending on the desired strength and rigidity, one can choose reinforcing elements of various diameters and plastic layers of various thicknesses.

 This invention also includes a plastic sheet or plate in which are embedded longitudinal and transverse metal wires which significantly increase its mechanical resistance and which at the same time are protected by the material against corrosion and deterioration by water and gas. The material may be formed from a single layer or a laminate of several layers, or it may be in a corrugated form with layers of plastic on one or both sides.

 The invention further includes new and improved methods and apparatus for manufacturing the above products, for forming a grid of longitudinal and transverse reinforcing elements and embedding them in a sheet of plastic, or for waving this grid and applying layers to it -of plastics in order to form a fairly rigid panel of appreciable thickness, having total resistance to humidity, and to form a corrugated panel of plastic material having a corrugated grid of longitudinal and transverse metal wires with layers of coating of a plastic material in which are grids of metal wires.

Yet another object of this invention is a material comprising a plastic sheet or plate reinforced with metal wires, and laminated with elastic and padding materials.

 The present invention relates to the formation of plastic materials in which a flat or corrugated reinforcing grid is associated with a plastic sheet to form a reinforced sheet of appreciable thickness in which the grid is corrugated and is located between two plastic sheets. The corrugated grid may or may not be covered with plastic and the covering plastic sheets may also be reinforced with grids. These plastic materials can also be laminated with sheets of elastic and padding materials for packaging or other uses. The manufacture of these plastic materials uses a method and an apparatus for drowning in a plastic material, for forming a reinforced sheet, individually or simultaneously, the sets of longitudinal and transverse metal wires arranged perpendicularly in the form of a grid. These sets of reinforcing elements, whether they are embedded or not, can then be corrugated and coated with plastic sheets sealed with the corrugated structure, sheets which can also be reinforced with metallic wires if desired. An elastic mat or padding can also be sealed with a reinforced plastic sheet or with a corrugated structure.

The present invention will be better understood with the aid of the description which follows and of the appended drawings in which
Figure 1 is a schematic representation of the apparatus for forming a plastic laminate containing longitudinal metal wires
Figure 1A is an enlarged cross-section of the laminate with the reinforcing threads disposed between the layers at an initial stage of product formation
Figure 1B is a cross section of Figure 1A taken along the line Ib-Ib of this figure
Figure 1C is a cross section of the complete laminate;
Figures 1B 'and 1C' correspond to Figures 1B and 1C, respectively, and show precisely the relative thickness of the plastic layers and the metallic reinforcing wires
Figure 2 illustrates another embodiment of the invention in which the reinforced laminate is formed with an adhesive;
Figure 2A is an enlarged cross-section of the laminate at an initial stage of its formation
fig # ure 2B is a cross section of Figure 2A taken along line 2B-2B of Figure 2A
Figure 3 is a plan view of one form of apparatus for feeding the yarns to the laminates of Figures 1 and 2
Figure 4 shows the apparatus for manufacturing a reinforced plastic sheet according to the invention
FIGS. 4A and 4B are cross-sections of two stages of formation of the reinforced plastic sheet obtained with the device of FIG. 4
FIG. 5 illustrates another embodiment of the invention for the formation of a laminate reinforced with metal wires
Figure 5A is a cross section at an initial stage of the formation of the laminate by the apparatus of Figure 5;
Figure 5B is a cross section of Figure SA taken along line 5B-5B of this figure;
Figure 5C is a cross section of the finished laminate formed by the apparatus of Figure 5
Figure 6 is a modified form of the apparatus of Figure 5 using an adhesive to form the laminate reinforced with metal wires
Figure 6A is a cross section at an initial stage of forming the laminate with the apparatus of Figure 6
Figure 6B is a cross section of Figure 6A taken along the line 6B-6B of Figure 6A; ;
FIG. 7 represents an embodiment of the invention for forming a laminate comprising metallic wires for reinforcement, both longitudinal and transverse
Figure 7A is a cross section of the reinforced laminate formed with the apparatus of Figure 7
Figure 7B is a cross section of Figure 7A taken along line 7B-7B of this figure
FIG. 7C is a view similar to FIG. 7B, showing more precisely the relative thicknesses of the plastic layers and the reinforcing wires
Figure 8 illustrates an apparatus for forming a plastic laminate having both longitudinal and transverse reinforcing metal wires with an adhesive to join the layers
Figure 8A is a cross section of the finished laminate formed by the apparatus of Figure 8;
Figure 8B is a cross section of Figure 8A taken along line 8A-8A of this figure
FIG. 9 shows an apparatus for forming a corrugated laminate in which metal reinforcing wires are embedded;
Figure 9A is a cross-section at an initial stage of the formation of the corrugated laminate produced by the apparatus of Figure 9
Figure 9B is a cross section of a form of the finished corrugated laminate produced by the apparatus of Figure 9
Figure 9C is a cross section of a modified form of the product of Figure 9B;
Figure 10 is a modified form of the apparatus of Figure 9 in which the outer layers of material are bonded to the corrugated material using an adhesive;
Figure 10A is a cross section of the product formed by the apparatus of apparatus 10;
Figure 10B is a cross section of a modified form of the product formed by the apparatus of Figure 10
FIG. 11 illustrates a method according to the invention for forming a grid of metal wires for the manufacture of a corrugated reinforced plastic material
Figure 11A is a cross section of the grid produced with the apparatus of Figure 11
Figure 12 shows an apparatus for forming a corrugated laminate with a grid of metal wires, for example the grid shown in Figure IlA
Figure 12A is a cross section of the product formed by the apparatus of Figure 12
FIG. 13 represents a modified embodiment of the invention for the manufacture of a reinforced, laminated and corrugated plastic material, according to this invention
Figures 13A, B and C are cross sections at successive stages of the formation of the product obtained with the apparatus of Figure 13;
Figure 13 is a cross section of the finished product formed with the apparatus of Figure 13
Figure 13E is a modified form of the product obtained with the apparatus of Figure 13;
Figure 13E 'is similar to Figure 13E and shows the thicknesses of the plastic layers and the reinforcing elements more precisely;
Figures 14 and 15 show combinations of plastic materials reinforced with cellular material and foam, respectively; and
Figures 16 and 17 show associations of corrugated and reinforced materials with cellular material and foam, respectively.

 As pointed out above, the product according to the invention comprises a plastic sheet or laminate with metallic reinforcing wires, or it can comprise a corrugated grid of coated or uncoated metallic wires, with layers of plastic material. on one or both sides. A method and apparatus for forming the reinforced plastic sheet according to this invention are shown in Figures 1 and 1A to C. But if the products which are obtained with the apparatus of Figure 1, as well as those obtained with the devices of Figures 2, 4, 5 and 6, can have many uses, it will be shown that they can also be used to form other types of reinforced articles according to the present invention for construction applications, packaging and others alike.

Referring now to Figure 1, which illustrates an embodiment of the invention for the manufacture of a plastic laminate in which are embedded longitudinal metal son reinforcement. More specifically, the apparatus comprises a heated drum 10, relatively large, on which the first film 11, which can be pre-coated with a thermosensitive adhesive, arrives from the roller 12 by the roller 13. If desired, the roller 13 can also be heated to raise the temperature of the film 11 just before its engagement on the drum 10. Immediately after the application of the film on the drum 10, a number of metal wires 14 arrive from coils 15 ', by rollers 15 and 16, on the drum 10, over the film 11.

The roller 16 preferably has spaced apart annular grooves or grooves for receiving the wires in order to maintain the desired spacing therebetween. The roller 15 which fixes the spacing between the wires will be described in detail
below about Figure 3.

A second film 17, which can be previously coated with a heat-sensitive adhesive, arrives from a roll 18 through the roll 19 to cover the metal wires 14. The laminate then advances around the drum 10, while being sufficiently heated so that the two films are sealed to each other, with the wires arranged between them. The temperature of the drum 10 is naturally a function of its speed so that an appropriate amount of heat is transmitted to the films. For example, if the drum 10 rotates at a relatively high speed, its temperature may be equal to or even higher than the melting point. of the film of my plastic material 11, while if the drum is to rotate at a low speed, it may be necessary to maintain its temperature a little below the melting point of the film.

The two films are sealed to each other by a pressure roller 20 which is preferably covered with a thin layer of polytetrafluoroethylene to avoid any risk of adhesion of the film to this roller, the coating of the roller 20 being designated. by the numerical reference 20 '. This roller 20 is preferably cooled by engagement with a cooling roller 21 because it is important that its surface is maintained at a temperature much lower than the melting point of the plastic, and preferably below its embossing temperature. The roll 20 also has the role of removing the finished laminate from the drum 10, after which the laminate passes around the cooling cylinders 22 and 23, then it is wound on a reel 24. FIG. 1A shows a longitudinal section of the laminate before sealing the films 11 and 17 to each other, FIG. 1B shows a transverse view of the laminate also before sealing the films, and FIG. 1C is a transverse view showing the two layers sealed together another, with the metal wires 14 arranged inside. Each film is normally about half the thickness of the wires; a more precise representation of the product obtained is shown in section in Figures lB 'and lC'.

It appears from the description of the apparatus of Figure 1 that if one wants to put only one film, for example film 11, and simply drown the son 14, these can be coated with a primer, - for example sodium silicate, or they can be covered with a very thin layer of a suitable plastic material, to promote their adhesion to the film 11.

In such a case, the wires, whether they have a primer and the plastic coating or simply the plastic coating itself, arrive on the surface of the film 11 as shown in FIG. 1, then the pressure roller. 20 makes them penetrate the film.

 To bring the wires 14 onto the film 11, it may be desirable or even necessary to maintain them under a certain determined tension. To this end, an auxiliary roller 16 'can be used pressing against the stiffened roller 16, and with a braking system on the roller 16', the tension on the threads can be precisely adjusted.

 A modified form of the apparatus of Figure 1 is illustrated in Figure 2, the same elements of these figures being designated by the same reference numerals. In the embodiment shown in FIG. 2, the film 11 is brought from a reel 12 onto a cylinder or drum 25 by means of an intermediate idler roller 26. An adhesive contained in a tank 27 is applied to the outer surface of this film by the rollers 28 and 29, then the coated film passes through a drying device 30, which can be an electric heating element or a housing with an inlet 31 and an outlet 32 for a supply of hot air passing over the surface of the film. The dried film then passes around the rollers 33 and 34 and it arrives at the drum 10. The other operations are the same as with respect to FIG. 1, except that the temperature of the drum 10 can be modified so as to heat the l adhesive sensitive to seal the films 11 and 17 together. The film 17 can also be coated like film 11 because if the two contact surfaces of the films are covered with heat-sensitive adhesive, this facilitates their sealing.

Figure 2A shows the initial relative positions of the metal wires 14, the layer 11 coated with adhesive and the layer 17 uncoated, Figure 2B is a cross section of Figure 2A, and Figure 2C shows the completed structure with adhesive III between the two layers.

 A wide variety of plastics can of course be used to form sheets 11 and 17, the choice of a particular material depending to a large extent on the end use for which the product is intended. It may for example be desirable to choose films having different characteristics as well as different colors for decorative purposes, and the films can be of thermoplastic or thermosetting nature. If a fairly high mechanical resistance is desired, in particular if the product is to be used at high temperatures or for construction applications, a thermosetting material is required, which must naturally have a first thermoplastic state, but which ultimately takes on a thermosetting state in the final product. It is also obvious that the layers of the plastic material may have a certain flexibility for certain uses, while for others it is possible to use relatively rigid plastics.

 For an article intended for a particular use in packaging, the most desirable plastics are undoubtedly products such as polyethylene, polystyrene, high density polyethylene, polypropylene, as well as polyamides and polyesters.

 The metal wires 14 can be guided towards the drum 10 by any suitable means, but a form of apparatus which can be used for this purpose is illustrated by FIG. 3 in which the roller 15, which guides the wires on the roller 16, comprises close disks 35 which maintain the desired spacing between the wires 14, which arrive from the coils 151 by a series of guides 36 which lead them between the disks of the roller 15.

With this arrangement, the roller 16 'will have an elastic surface and will press against the wires 14 on the roller 16.

Such an arrangement makes it possible to effectively adjust the tension of the threads and one no longer has to rely solely on their friction with the roller 16 to adjust their tension.

FIG. 4 shows another embodiment of the invention in which a plastic material is extruded directly on a drum, in contact with longitudinal reinforcing elements such as metal wires. In this embodiment, the drum 37 is preferably cooled by a circulation of water or of another suitable refrigerant which passes through it, and the wires 14 arrive from coils 15 ′ by the roller 16 on the surface of the drum. 37, this may or may not have fine grooves for receiving the wires, but in most cases, it will not be necessary to groove the drum if an appropriate tension is maintained on the wires. on the drum 37, a plastic material 38 is extruded thereon by an extruder 39, preferably with a single die. As this extruded material is at a very high temperature, it surrounds the wires as shown in FIG. 4A, then it cools gradually until it reaches the take-up roller 40, which is cooled to lower the temperature of the sheet so that it can pass around the roller 41 and can be wound on the reel 42. The finished product, shown in FIG. 4B, is then ready either for another treatment or for the direct use envisaged. product form 4B is practically identical to that of the product previously described with reference to FIG. 1 when a single film il is used in which the metal wires are embedded. Naturally, as regards FIG. 4, the wires 14 can be coated or not, as desired.

 Another embodiment of the invention is shown in Figure 5, in which a film 43, which may have been previously perforated, arrives from a reel 44, by a roller 45, on a drum 46, and also soon after when it is applied to this drum, metallic wires 47 arrive from coils 15 ′, via rollers 48 and 48 ′, on the surface of the perforated film, rollers 48 and 48 ′ essentially corresponding to rollers 15 and 16 in FIG. 1. A second non-perforated film 49 arrives from a reel 50, by a roller 51, to cover the wires 43 arranged longitudinally. At this stage of the process, the structure of the product formed is shown in FIG. SA which shows the relative positions of the films 43 and 49, with the wires 47 arranged in between, the perforations of the film 43 being designated by the reference numeral 43 '. Figure 5B is a cross section of Figure SA.

 The laminate (53) then moves downward between the heating elements 52 and then passes around a roller 54 having vacuum orifices distributed over its entire surface and which is also cooled by circulation of a refrigerant. The particular structure of the roller 54 is of a well known technique.

 The heat provided to the laminate 53 by the heating elements 52 is sufficient to obtain a good seal between the films 43 and 49 between which the metal wires are disposed, but if desired, this roller 54 can be associated with a pressure roller 55 for ensure satisfactory sealing. The films 43 and 49 between which the wires 47 are placed are then further cooled by a roller 56, then they pass over a roller 57 and finally they are wound on the reel 58. The product thus formed is shown in cross section on the Figure 5C, although in practice the thickness of the assembly of the two films may not exceed the thickness of the wires.

 The embodiment of the invention which is shown in FIG. 6 is practically identical to that illustrated in FIG. 5, except that one of the sheets of the plastic material is coated with a heat-sensitive adhesive before being laminated. with the other sheet, and in these two figures, the same reference numerals designate the same elements. In this embodiment, the film 43 first arrives on the roller 46 in the manner described with respect to FIG. 5, then the metal wires arranged longitudinally arrive to be placed over this film. The film 49 arrives from a reel 50, through the rollers 59 and 60, on the drum 61. An adhesive contained in the tank 62 is applied to the surface of the film 49 by the rollers 63 and 64, after which this film passes by the roller 51 and it is dried by a radiant heating element 65 and / or by hot air, as desired. The coated film leaving the roller 61 passes around the roller 50 and then on the roller 46 to cover the wires, which gives an initial laminate 53 which is shown in section in FIGS. 6A and 6B. This laminate then passes between the heating elements 52 -52, and from there around the cooled vacuum roller 54, which, as a result of the perforation of the film 43, causes the two films to adhere to one another. However, since the heat-sensitive adhesive has been applied, the temperature of the films must not be as high as for the sealing as in the case of the apparatus of FIG. 5, with the consequence that one of the films, namely the film 49, will be slightly deformed to apply tightly around the wires 47, as shown in FIG. 6C on which the adhesive is designated by the reference 49 '.

To obtain an even better seal, it is possible optionally to associate a pressure roller 55 with the roller 54, in which case the product obtained will have a shape closer to that of the product of FIG. 5C. In FIGS. 6A to 6C, the thickness of the films has been enlarged by way of illustration.

In the previous embodiments of this invention, a laminate was formed with metal wires arranged longitudinally and a layer of plastic material on one side of the wires or on both sides, as the case may be, but it is obvious that in these embodiments, one of the films can be previously formed with wires arranged transversely, which gives a product with metallic wires arranged both transversely and longitudinally, thus forming a grid coated in the plastic.

It is also obvious that one can choose various dimensions of metal wires and various thicknesses and types of plastic materials, according to the use for which the article is intended.

Figures 7 and 8 show two embodiments of the invention for the manufacture of products comprising metal wires both longitudinal and transverse which are embedded in plastic sheets. Although various methods can be applied to form a plastic sheet with transverse metal wires, a good method is to take a product such as that shown in Figure 1C, 1C ', 2C, 4B, 5C or 6C, and cut it to lengths equivalent to the width of the desired sheet.

Each separate part is rotated by 900 and then the successive parts are fixed to each other by hot sealing or by another suitable means, which gives a film in which the wires are arranged transversely. Such a product can be used with the apparatus of FIG. 7.

The apparatus of FIG. 7 comprises a drum 69 with vacuum orifices distributed over its surface and a device for circulating a fluid suitable for regulating its temperature, which is desirable since heating means are provided around the drum, as will be described, to heat the films for their stratification. A first film 70 arrives from a reel 71, by a roller 72, on the drum 69, then metallic wires 73 arranged longitudinally arrive from reels 15 ′, by the rollers 74 and 75, to be applied to the film 70, these rollers 74 and 75 essentially corresponding to the rollers 15 and 16 of FIG. 1. A perforating drum 76 with teeth or points perforates the film 70, and the vacuum produced inside the drum 69 makes the film closely adhere to the surface The film 70 with the wires 73 then passes below the heating element 77 which raises their temperature in the vicinity of the melting point of the film. A second film 78 arrives from a reel 79 by the roller 80 to be applied to the wires 73, then the whole passes through the heating element 81 which heats the external film by bringing it to the temperature necessary to seal it at the first film 70.

 Either of the films 70 and 78 contains transverse metal wires, films which can be obtained in the manner described above.

The heated product then passes between the drum 69 and a roller 82 to seal the two films, which then pass around the roller 82 and then on the rollers 83 and 84, the rollers 82, 83 and 84 also having the role of cooling the laminate. , so that the laminate 85 formed is ready to be wound on a spool or to be sent to a further processing operation. The laminate 85 thus formed is shown in Figures 7A and 7B. In this case, the film 70 comprises several metal wires 70 ′, and the wires 73 are arranged between the films 70 and 78.

A cross section of Figure 7A is shown in Figure 7B. FIG. 7C is similar to FIG. 7B, but it shows in a more precise manner the relative thicknesses of the layers of the plastic material and of the metallic wires.

The apparatus shown in Figure 8 differs from that in Figure 7 in that an adhesive is applied to join the two plastic sheets together. In this embodiment of the invention, a drum 69 is practically identical to that of FIG. 7, and the first film 70 arrives from a reel 71, by the roller 72, on the drum 69, while metallic wires 73 arrive from coils 15 ′, through rollers 74 and 75, to be applied to the film 70, then the wires and the film pass below the heating element 77 to be brought to the sealing temperature. Another film 78 comes from a reel 79, passing around a roller 80, onto a drum 86 having a heating system 87 surrounding part of its periphery. An adhesive placed in the tank 48 is applied by the rollers 89 and 90 on the outer surface of the film 78, then this film coated with adhesive is dried by the element 87 to then cover the wires 73 on the drum 69, which, by its heating element 81, further heats the laminate to perfect the seal between the two films between
which are arranged the metal wires 73. As in the case of FIG. 7, one or the other of the films
70 and 78 preferably comprises wires arranged transversely, and the laminate obtained then comprises metal wires that are both longitudinal and transverse
forming a grid embedded in the plastic.
the finished laminate then passes around the rollers 82, 83 and 84, which are preferably cooled, so that the
laminate 85 'is ready for further processing or for
between stored. If desired, the roller 82 can press against the laminate passing between it and the drum 69, both in the case of FIG. 8 and in the case of the
Figure 7, to ensure regular sealing of the two layers. The laminate 85 ′ thus obtained is represented on
FIG. 8A, with the film 70 and the metal wires 70 ′ in this film, a layer of adhesive 78 ′ and the other layer of plastic 78, the wires 73 being naturally placed between the two layers. Figure 8B is a cross section of Figure 8A.

FIG. 9 illustrates an embodiment of the invention for the production of a reinforced corrugated laminate which can be used to form various products for packaging articles, as well as as building elements. Such a laminate essentially comprises a corrugated part with covering layers on one or both of its sides, the corrugated part preferably being reinforced by metal wires arranged transversely although it is also possible to lay longitudinal wires, and the covering layers which may likewise be reinforced by longitudinal or transverse metal wires or by both at the same time, as the case may be.

In this embodiment, the first plastic sheet 9l, which has preferably been previously coated with an adhesive, arrives from a reel 92, by a roller 93, on a drum 94 whose temperature can be adjusted so to bring the film 91 in the vicinity of its melting point. The film 91 may naturally comprise transverse metal wires as has been described in connection with the embodiments corresponding to FIGS. 7 and 8, or it may be without reinforcing elements. Metal wires 95 arranged longitudinally arranged then arrive from several coils 15 ', passing around rollers 96 and 97 (rollers 15 and 16 in FIG. 3) on the drum 94 to be applied to the film 91, quite in the manner which has been described with reference to the figure 3, and a second film 98 arrives from a reel 99, through the roller 100, on the drum 94, to cover the wires 95, this second film may or may not be provided with longitudinal reinforcing metal wires, such as the film 91.

The laminate thus formed then descends through a heating element 101 and then it passes around the rollers 102 and 103 to reach the corrugation rollers 104 and 105. If the film 91 is perforated in the manner which has been described in connection with the apparatuses of the Figures 7 and 8 or if it has been previously perforated, the roller 102 will be provided with several vacuum orifices connected to a device for evacuating in a well known manner, and the sealing of the two films will then be done on this vacuum roller .If on the contrary the film 91 is not perforated, the rollers 102 and 103 can be placed very close to each other so as to exert sufficient pressure for a good sealing, but in both cases the roller 103 preferably be cooled to lower the temperature of the laminate before it engages between the corrugation rollers 104 and 105o
The laminate designated by the reference 106 then descends through a heating element 107 so that at least the surface layers are again brought to an appropriate sealing temperature, then a third film 108, preferably s previously coated with an adhesive and which may or may not include reinforcing metal wires, arrives from a reel 109 passing around the rollers 110 and 111, the latter being heated to bring the adhesive to a temperature suitable for sealing, and this heated film 108 passes over a roll 112 which can also be heated and which brings it into contact with the corrugated laminate 106. A fourth film 113 similar to the film 108, and preferably also previously coated, arrives from a reel 14, passing through the rollers 115 , 116 and 117, to cover the other side of the corrugated laminate 106. The roll 116 is heated like the roll 111, and if desired the roll 117 can also be heated to maintain the pel modulates 113 at the sealing temperature, as in the case of film 108.

 The corrugated laminate 106 with the covering layers 108 and 113 then passes between two cooling strips 118 and 119, the strip 118 being carried by cooled rolls 120 and i21 and the strip 119 by cooled rolls 122 and 123, and these two the strips being sufficiently close to one another to exert pressure on the laminate in order to seal the covering layers to the corrugated structure 106 without, however, deforming it. The product thus obtained, designated by the reference numeral 124, is then ready for use or for another treatment.

 A cross section of the corrugated structure 106 is shown in Figure 9A in which the thickness of the plastic layers has been enlarged for better illustration. It will be observed that the film 91 comprises transverse metal wires 91 ′, longitudinal metal wires 95 and the plastic layer 98. The final product 124 shown in FIG. 9B comprises the corrugated structure 106 with the longitudinal and transverse wires and the two layers of plastic coating 108 and 113. A modified form designated by the reference 124 'is shown in cross section in FIG. 9C, a form in which the structure 106 comprises the layers 108 and 113 as in the case of FIG. 9B, but also transverse reinforcing metal wires 108 ′ and 113 ′. Naturally, the covering layers 108 and 113 may also include both longitudinal and transverse reinforcing metal wires, as shown for example in FIG. 13E which will be described below.

 The embodiment of the invention which is shown in Figure 10 is similar to that of Figure 9, and in these two figures the same reference numerals denote the same elements. The formation of the reinforced corrugated laminated structure 106 is substantially identical to that illustrated and described with reference to FIG. 9, however, the covering layers are coated with an adhesive just before their application to the corrugated structure. More precisely, the film 125 arrives from the reel 126 on the rollers 127 and 128 and from there it passes in an upward movement through an oven 129. A tank 130 contains an adhesive which is applied to the film 125 by a roller 131, the adhesive is then dried in the oven 129 then it is brought into contact, by the rollers 132 and 133, with one side of the corrugated structure 106. The device for applying the second film 134 on the other side of the corrugated structure 106 is identical to that described below. above, and the same reference numerals designate the same elements. The corrugated structure 106, with the two films 125 and 134, descends between cooling cylinders 135, 135 ', 136 and 136' to be cooled and to ensure good adhesion of the outer layers. The product thus formed is designated by the reference 137 and it is shown in cross section in FIG. 10A in which the corrugated structure 106 is identical to that of FIG. 9A and includes the outer layers 125 and 134 linked to the corrugated structure by the layers of adhesive 125 'and 134' . The outer layers 125 and 134 may comprise metallic reinforcing wires as shown in FIG. 10B, in which the reinforcing wires are designated by the reference 138 in the layer 125 and by the reference 139 in the layer 134.

Reinforcement wires arranged longitudinally are also preferably incorporated in the external layers, as shown in FIG. 13E which will be described later.

 In the embodiments of the invention which have just been described, such as those corresponding to FIGS. 1 and 4 to 10, a grid of metallic wires can be used in place of the longitudinal wires, in which case a layer of material plastic in which the transverse wires are embedded is no longer necessary. Thus, in FIG. 9 for example, the films 91 and 98 do not require the presence of transverse wires if it is possible to bring a grid of wires between them instead of the simple longitudinal wires 95. An improved method and apparatus for forming such a grid are illustrated in FIG. 11.

In the figure read, a transversely corrugated strip, designated by the reference 140, is carried by a pair of drums of which only one is represented in the figure and designated by the reference 141. A suitable device makes it possible to cut metal wires to lengths determined and bring them individually into the hollows or grooves of the strip 140. These wires, which are designated by the reference 142, are represented on the upper side of the strip and they advance in the direction of the drum 141. Several narrow strips 143, carried by sets of rollers 144, 145 and 146, hold the wires 142 in position on the corrugated strip 140 when the latter descends around the left side (in FIG. 11) of the drum 141. As each wire reaches the part the lowest, it is placed on a drum 147 provided with hooks 148 axially aligned and arranged on its periphery, and as each wire is deposited on the drum 147 it is engaged by a set of hooks and it is thus held in position as this drum rotates.

Furthermore, a set of metal wires arranged in a longitudinal direction, designated by the reference L49, arrives from several coils 15 'exactly as in the case of FIG. 3. These wires 149 pass around the rollers 150 and 151 which correspond to the rollers 15 and 16 of Figure 3, then between the roller 151 and another roller 152, the latter roller preferably being grooved to maintain the desired spacing between the wires. The wires 149 then pass below the heating element 153 and then on the roller 154 which is coated with an elastic layer 155 and which preferably has grooves to release the axial rows of hooks 148 from the roller 147.

The wires 149 pass over the surface of the layer 155 of the roller 154 and then they engage closely with each of the transverse metallic z 142 forming a grid.

However, in the preferred embodiment, the wires 149 are covered with a heat-sensitive adhesive or with a plastic material so as to ensure a solid bond between the two sets of wires. The metal wires thus joined together, which now form a grid, are carried by the roller 147 and they are guided on the reel 157 by the roller 156. it is naturally preferable for the drum 147 to be cooled in order to rapidly lower the temperature of the wires metal after they have been brought together. A cross section of the grid thus formed is represented in FIG. 11A in which it can be seen that the longitudinal wires 149 grip by pinching the transverse wires 142. If the two sets of metal wires have been previously covered with a plastic material or of an appropriate adhesive of the heat-sensitive type, this will facilitate the formation of a structure in which the grid of wires will be corrugated and then to which layers of coating will be applied as will be described with reference to FIG. 12
In FIG. 12, a grid of wires 158 arrives from a coil 159, by a roller 160, to the corrugated rollers 161 and 162. The corrugated grid which then leaves these rollers, designated by the reference 158, passes through a heating element 163 then it descends between two strips 164 and 165, the strip 164 being carried by a pair of rollers 166 and 167 and the strip 165 by the pair of rollers 168 and 169, and these two pairs of rollers being preferably cooled to maintain the strips at a temperature much lower than the melting point or the embossing temperature of the films to be now applied to the surface of the corrugated structure A first plastic film 172 arrives from a reel 171 by the roll 172 on the outside of the strip 164 as the latter passes around the roll 166, and a second film 173 arrives from a reel 174 by the roll 175 on the strip 165 when the latter passes to the upper part of the roll 168. As the fi the metal has been heated to a relatively high temperature by the element 163, ifs heat the films sufficiently when they are pressed by the rollers 166 and 168 to be brought into contact with the wires, and at the same time the rollers acting by means of strips 164 and 165, maintain the films 170, 173 in solid engagement with the corrugated grid, while the assembly is cooled. The product thus obtained, designated by the reference numeral 176, is represented in FIG. 12A , the corrugated grid being designated by the reference 158 ', and it will be observed that the external parts of the grid are embedded in the outer layers of plastic material 170 and 173. In most cases where a grid of metal wires is used , it is best to coat the wires to protect the metal from corrosion.

 Another modification of the invention is illustrated in FIG. 13 which shows an apparatus and a method for the continuous production of a corrugated structure, process in which one begins by forming a reinforced corrugated layer, on which the layers of recovery. In this figure, metal wires 180 arranged longitudinally arrive from several coils 15 'through the rollers 181 and 182 (which correspond to the rollers 15 and 16 of FIG. 3) on a cooling drum 183 which can be cooled by a circulation of water or another cooling liquid, in a well known manner, and immediately after the application of the wires, a layer of plastic material 188 is applied to the drum 183 by an extruder 184.

A plastic sheet or film 185 then arrives from a reel 186 by the roller 187 to cover the extruded layer 188. Since this layer 188 is at a relatively high temperature, it coats the wires 180, and since it is at least at normal sealing temperature it adheres well to the film 185 which is applied immediately after extrusion. The layer 185 will preferably be a film which has been previously treated for another associated with metal wires placed transversely in the manner previously described. FIG. 13A shows a cross section of the wires 180 as soon as the layer 188 has been extruded on the drum 183 to cover the wires. FIG. 13B is a cross section after the film 185 has been applied to the extruded layer 188, and it can be seen in this figure that the layer 185 contains transverse metal wires 185 '. The structure of FIG. 13B which was formed on the drum 183, is then removed from this drum by a roller 189, then it passes through a heating element 190 and from there it goes to a pair of corrugated cylinders 191 and 192. The corrugated product which leaves, designated by the reference 193, then passes over the rollers 194, 195 and 196, then the roller. 198 fines it on a second cooling drum 197, but before applying the structure 193 to this drum, a second extruder 199 applies a layer of plastic 200 on the drum 197. Although this drum is cooled like the drum 183, the plastic layer 200 is at a fairly high temperature and after the application of the corrugated structure 193, the latter adheres firmly to this layer 200. The product thus formed, which is shown in cross section in FIG. 13C , is then removed from the drum 197 by a roller 201, which brings it, passing around the rollers 202 and 203, on the drum 204, but before its application on this drum 204, and while it is already on the one of its sides a layer of plastic, a third extruder 205 applies a second layer of plastic 206 to the drum, which forms a second coating on the corrugated structure. As the extruded layer 206 is at a high temperature l When the corrugated structure is applied, the two adhere firmly to each other, after which this layer 206 is cooled by the drum 204 as the layers 188 and 200 have been cooled by the respective drums 183 and 197. The final product resulting, which is designated by the reference 208, is then removed from the drum by the roller 207.

A cross section of this product 208 is shown in Figure 13D which shows the relative positions of the various layers comprising the reinforcing metal wires in the corrugated structure.

From the above description, it is quite obvious that reinforced layers like those seen in Figures 7B and 7C, and 8B, can serve as outer layers to form the corrugated structure
with the apparatus of FIG. 13, in place of the layers applied by the extruders 199 and 205, and in such a case the reinforced layers will be preheated before being brought to the drums 197 and 204 so that they are sufficiently hot to ensure sealing with the corrugated structure 193 The use of external layers 209 and 210 like those of FIGS. 7B and 7C, and 8B, will give a product as shown in FIG. 13E, but in the latter case it is not generally necessary to put longitudinal metal wires in the corrugated structure because the external layers give the product sufficient resistance. By way of illustration, the thicknesses of the layers of plastic and of the metal wires have been exaggerated in FIGS. 13A to 13E. ha Figure 13E 'shows more precisely the relative thicknesses of the plastic layers and the son of the product of Figure 13E
It is obvious that the various products which can be manufactured in accordance with the present invention can be used alone or combined with the other types of packaging materials to meet very diverse needs in the packaging industry.

For example, the element 85 of FIG. 7A can be associated, as shown in FIG. 14, with a cellular material 211 to obtain a rigid wall covered on at least one of its sides by the padding material, and that -this can take any suitable form and can be a material as described for example in US Patent No. 3,142,590 Figure 15 shows another modification of the invention in which the layer as is associated with a plastic foam 212, polyurethane or other suitable material.

Naturally, if FIGS. 14 and 15 show the reinforced plastic layers 85 p, similar combinations can be made with the reinforced layers of other previous figures. FIGS. 16 and 17 show still other products which can be produced in conformity In FIG. 16, the product of FIG. 13E is combined with the cellular material 211, while in FIG. 17, this same product is corbin with a foam of plastic material 2120 It is naturally also obvious that the product of Figure 13D can replace that of Figure 13E, and that even a product such as that of Figure 13C can be used as shown or can be reinforced by metal wires arranged longitudinally or transversely.

 In all the embodiments of the present invention which have just been described and illustrated, it is obvious that it is possible to use various types of material for these manufactures. For example, the reinforcing elements can be steel wires. having the desired carbon content, and you can also use various steel alloys as well as aluminum, copper or other similar metals giving the necessary mechanical strength and stiffness, as well as one can choose also light metals like magnesium or even tungsten, if weight is an important factor. As far as plastic is concerned, polyethylenes of various densities can be used, polypropylenes and their copolymers, polystyrenes or polyvinyl chloride, as well as various polyesters and polyamides. Thermosetting resins can also be used for various applications, for example flexible modified phenolic resins, as well as phenol-formaldehyde, urea formaldehyde, furfural-formaldehyde and melamine-formaldehyde resins.

To obtain good resistance to water vapor and other gases, the plastic sheets can be covered beforehand with a film of polyvinylidene chloride or another similar plastic material relatively impermeable to gases. As said previously, the various products obtained have been shown in the drawings in most cases, for clarity, with exaggerated thicknesses of the layers of plastic and adhesive, but in all cases the layers plastic generally have a thickness of about half that of the reinforcing metal wires. Naturally, the number of wires per centimeter, their thickness, as well as the thickness and the type of plastic layers, can all be modified to obtain the desired mechanical strength, just as the arrangement of the reinforcement wires can also be chosen from way to achieve the desired results.

For example, if there are wires both longitudinally and transversely in the layers which cover the corrugated structure, it may not be necessary to put longitudinal wires in the central corrugated part. Finally, the metallic wires which are employed according to this invention may have a section
any transverse, for example circular, square, more or less oval or others.

Claims (11)

 1.- Plastic material reinforced with metallic wires, comprising a corrugated plastic layer reinforced with metallic wires, the plastic layer and the wires being both corrugated and the corrugations of the plastic layer being transverse with respect to the wires, with a sheet of plastic bound at least one side of the corrugated layer, on the crests of the corrugations.  2. Reinforced plastic material according to claim I, in which a second external layer of plastic adheres to the other side of the corrugated layer.  3.- A method of manufacturing the reinforced plastic material according to claim 1, comprising adhering to a layer of plastic metal wires spaced parallel to each other, waving this layer transversely to the son, then adhere a second layer of plastic, on at least one side of the corrugated layer, to the crests of the corrugations thereof. 4.- Method according to claim 3, wherein a third layer of plastic is adhered over the son before proceeding to the corrugation. 5.- Method according to claim 4, wherein one of the layers comprises metal wires arranged transversely and spaced parallel to each other, which are fixed thereto.  6. A method according to claim 4, in which the third layer is brought to a drum, a second set of wires parallel to this layer placed on the drum is adhered, the layer is cut into pieces which are placed side by side. side to form a continuous succession, with the wires arranged transversely, this succession of pieces is adhered over the first layer to which the wires are linked, then the finished laminate is corrugated and the covering layer is applied to it.  7. A method according to claim 6, wherein a second coating layer is further adhered to the crests of the corrugations on the other side of the corrugated laminate.  8.- The method of claim 7, wherein at least one of the coating layers comprises a plastic material reinforced with metal son.  9.- The method of claim 4 for forming a plastic material reinforced with metal son, consist in bringing a layer of plastic material around a first drum, in bringing a second layer around a second drum very close to the first, to bring metallic wires spaced between these layers as they pass between the drums, to make the two layers adhere securely to each other with the wires arranged between them to complete the laminate, to undulate it transversely then adhering a plastic coating layer, on at least one of the sides of the corrugated laminate, to the ridges of the corrugations of this laminate.  10.- The method of claim 9, wherein the layers are heated to their sealing temperature during their movement on the drums and the drums are advanced towards each other to seal the layers, with the wires arranged between them  llo ~ Apparatus for carrying out the method according to claim 3, comprising a heated drum, means for bringing a layer of plastic material around this drum, means for adhering space metal wires parallel to each other over the layer which is on the drum and in the direction of its length, a pair of corrugation rollers, means for passing between these rollers the assembly constituted by the plastic material and the wires, and means to adhere a second layer of plastic, on at least one of the sides of the corrugated assembly, to the crests of the corrugations of this assembly.  12.- Apparatus according to claim 11, further comprising a second drum contiguous to the first, means for bringing a third layer of plastic material around this second drum and means for pressing it against the first drum to adhere the third layer to the first over the wires, to coat them between the first and the third layers. 13.- Apparatus according to claim 12, further comprising means for adhering a fourth layer of plastic material to the crests of the corrugations on the other side of the corrugated assembly formed of the plastic material and the son.