FR2682133A1 - LAMELLAR BRISTOL LIGHT. - Google Patents

Abstract

Light lamellar Bristol board, characterized in that it comprises: - at least two layers of flat card stock (12, 14) having a thickness between 0.3 mm and 1.5 mm, the outer surfaces of these two layers (12, 14) being flat and smooth; - and at least one inner layer of profiled card stock (16), the thickness of which is between 0.23 mm and 0.5 mm, comprising ridges (16b) and valleys (16a), placed and glued between the inner surfaces ( 12a, 14a) of each of said two layers of card stock, these ridges (16b) and these valleys (16a) having a height of between 0.90 mm and 1.2 mm; said inner layer of profiled card stock (16) having a number of sets (18) of ridges (16b) and valleys (16a) of between 350 and 400 per linear meter of card stock; and in that the convex curved surfaces (16a) of at least one of the faces of this inner layer of profiled card stock (16) are indented in the inner surface (12a) of at least one (12) of the layers of flat card stock, for example to a depth of 0.1 mm, in order to increase the surface area of the contact zone and of the gluing zone between these layers, and this in order to ultimately increase the rigidity and resistance of this card stock lamellar.

Description

1 -

Light lamellar Bristol.

  The present invention relates to a new lamellar bristol, and more specifically a new lamellar bristol incorporating a central sheet with alternate ridges and valleys, which has the rigidity and resistance characteristics of lamellar bristol

  full, but is 30 to 45 Z lighter in weight.

  Lamellar bristol or paperboard consisting of two or more flat sheets glued together is normally used for the manufacture of book covers, loose leaf binders, table game trays, and other articles. similar, which require a number of characteristics: rigidity, resistance, stability, surfaces

  smooth exterior, doubling and folding resistance.

  It is to have these characteristics that lamellar bristol or cardboard pulp with flat layers bonded together is manufactured in order to obtain a solid mass which is however relatively heavy and expensive to manufacture because of the large quantity of

Bristol paper needed.

  In order to remedy these problems, corrugated cardboard has been used, which incorporates a corrugated inner layer of card stock intended to replace one or more of the flat layers and which contains interior spaces. However, this cardboard does not have the stiffness nor the strength necessary to substitute for the solid lamellar bristol commonly used for the manufacture of book covers, binders of loose leaves, table game trays and other similar articles In particular, this cardboard of Le, even It is light in weight, can be bent and folded easily It is not satisfactory either on the plane of the smooth outer surface, since the ridges of the corrugated or corrugated sheet are manifested through the sheets or outer liners Thinners usually used for corrugated cardboard As a consequence, 2-corrugated cardboard is not the appropriate material likely to replace the lamellar bristol ring when we pretend to reduce

weight and the cost of the latter.

  The existence of a form of corrugated cardboard is also known, said, in the industry, "wrinkled corrugated bristol", which has about 295 corrugations per linear meter of bristol This number of wrinkles relatively high compared to other commonly used corrugated cardboard does not provide sufficient resistance to doubling and bending, nor does it provide sufficiently smooth outer surfaces, which is why it can not satisfactorily replace the usual solid lamellar bristol used for the manufacture of bindings of loose sheets, book covers, trays

  board games and other similar articles.

  Finally, we also know the use of outer sheets of a higher weight incorporating a corrugated central sheet type E intended to increase the rigidity and flexibility But this cardboard is also not resistant enough to the doubling and folding, and the ridges of the corrugated central leaf always appear through the outer leaf, thus creating a

irregular outer surface.

  The present invention therefore has the particular object of overcoming the above-mentioned drawbacks. It thus proposes a lamellar bristol board incorporating a central sheet with alternate ridges and valleys, which is light in weight and therefore less expensive in terms of manufacture, but which nevertheless has the characteristics of stiffness and bending resistance, and a smooth outer surface comparable to

  those of flat lamellar bristols with flat leaves.

  The present invention also aims to provide a lamellar bristol designed to offer greater rigidity and greater strength, given the large number of ridges and valleys it has and because of the increase in surface of the faces glued between the different layers by indentation in the

surfaces of adjacent layers.

  It is another object of the present invention to provide lamellar bristol material designed to provide greater parallelism and higher moisture stability due to specially designed ridges and valleys and their weak interaction. compared to

that of solid lamellar bristol.

  The present invention is constituted by a lamellar bristol board having at least a first and a second cardboard layers having a flat and smooth outer surface, and separated by at least one inner layer of profiled bristol board placed and bonded between said first and second layers exterior of the cardboard The inner layer of the profiled bristol board consists of profiles specially designed on the basis of ridges and

  Curved valleys according to an alternative model.

  The convex or crowned curved surfaces of one of the faces of the inner layer of profiled bristol board are indented at least by at least 1 mm in at least one of the first and second outer layers of cardboard, in order to increase the surface area of the board. contact and the bonding surface between the layers, with the aim of increasing the rigidity and

Resistance of lamellar bristol.

  The ridges and valleys of the inner layer of profiled bristol have a relatively low height, while the number of ridges and valleys per linear meter is relatively high. These characteristics, combined with the characteristic of increasing the contact surface and the bonding surface between the layers, make it possible to achieve an improved lamellar bristol substantially compared to conventional solid lamellar bristol, lighter in weight and less expensive manufacturing than the latter, since it requires less material, while nevertheless being substantially comparable in terms of rigidity, strength and resistance to folding, solid lamellar bristol, heavier and incorporating glued flat layers

  together to obtain a full mass.

  The present invention also includes the incorporation of two or more inner layers of profiled bristol board, each of which is in place and glued between the adjacent outer layers of flat bristol board. This lamination board with additional inner profiled layers is useful. in some cases that require a thicker and stiffer card stock, for example, large book covers, loose leaf binders, and

other similar articles.

  According to a third embodiment of the present invention, the ridges and valleys of the first inner layer of profiled bristol board extend in a first direction, while the ridges and valleys of the second inner layer of profiled bristol board extend in a second direction, arranged at 90 degrees with respect to the first, thus giving rise to a lamellar bristol which has ridges and valleys offset between them at 90 degrees (which will be called "crossed ridges" in the rest of this exposed) making it possible to further increase the rigidity and the resistance of the lamellar bristol forming the object of the present invention. The whole system configures a device in which the direction of the

  grain of both layers is balanced.

  The present invention therefore advantageously proposes a lamellar bristol, which is light in weight and is less expensive to manufacture than heavier solid, flat-leaf bristol, in spite of which their characteristics are substantially comparable in terms of strength.

  stiffness and resistance to bending.

  Other objects, features and benefits of the

  present invention will manifest in the description

  details of the embodiments selected here as examples, and presented together with the appended drawings in which: FIG. 1 is a perspective view, and partially

  in section, light lamellar bristol according to the invention.

  Figure 2 is a sectional view and on a larger scale of the embodiment according to Figure 1; it shows the profiled bristol layer placed and glued between the

  flat outer layers of the cardboard.

  FIG. 3 is a view in section and on a larger scale of the profiled bristol layer and the degree of indentation thereof in the outer layers of

flat bristol.

  FIG. 4 is a sectional view of a modified embodiment of the present invention incorporating a second

layer of cardboard.

  Fig. 5 is a partially cutaway perspective view of a third embodiment of the present invention, wherein a profiled bristol layer is set at 90 degrees to a

  second layer of profiled Bristol board.

  According to the first embodiment illustrated in Figures 1 and 2, the lamellar britol 10 consists of three layers 12, 14 and 16 The outer layers 12 and 14 are flat on the outer surface; they are made of cardboard, each having a thickness which is advantageously between 0 3 mm and 1 5 mm (

from 0 012 "to 0 060").

  The inner layer 16 of profiled bristol is formed of profiles designed especially on the basis of curved valleys 16 a and curved crests 16 b arranged alternately, its thickness being between 0 23 mm and 0 5 mm (or from 0 009 "to 020 ") The corrugated layer 16 is positioned and bonded between the inner surfaces of each of the outer layers 12 and 14 along the upper and lower convex curved surfaces 16a and 16b. A curved surface 16a and a curved surface adjacent 16 b constitute a set of opposite curved surfaces, designated by reference 18 in Figure 2 Each set of curved surfaces 18 has a height of between 0 90 mm and 1 2 mm (0355 to 0 047 "), the number of games 18 being between 350 to 400 per linear meter of card stock In the case of the embodiment selected, there are 375 sets of curved surfaces 18 per linear meter, and the surfaces

  curves have a preferred height of 10 mm (ie 0 039 ").

  For the manufacture of lamellar bristol 10, the layer 16 itself carries the sizing, and the layers 12 and 16 are passed between rollers exerting a force sufficient to jointly press the two layers to obtain the same. As a result, the convex curved surfaces 16 adhere to the inner surface 12a of the layer 12; the pressure exerted causes the curved surfaces 16a to indent into the surface 12a, at least over a thickness of between 0 1 mm (004 ") and 0 25 mm

(0.010 ").

  According to the exemplary embodiment adopted, the degree of indentation is 0 2 mm (0.008 "), which has the effect of increasing the contact surface between the surfaces 16 a and 12 a, so that the adhesion zone between layers 12 and 16 also increases As a result, the stiffness and strength of the cardboard

  lamellar 10 increase substantially.

  With the layer 16 carrying the sizing applied on itself, it is then possible to adhere the assembly constituted by the layers 12 and 16, to the layer 14, by passing through the pressing equipment, through these layers, this equipment to exert sufficient pressure to interweave the union of said layers and to weakly embed the convex curved surfaces 16b in the surface

internal 14a of the layer 14.

  According to the exemplary embodiment of lamellar bristol 10, the surface of the zone of contact between the surfaces 12a and 16a is at least twice the surface of the zone of contact between the surfaces 14a and 16b. , the total thickness of the lamellar bristol 10 thus produced, is between 1 5 mm and 4 70 mm (0.060 "to 0 185"); according to the exemplary embodiment retained, it is between 20 mm and 30 mm (from 0 079 "to

0.118 ").

  FIG. 3 is a detail view of FIG. 2, which shows more clearly the degree of indentation between the curved surfaces 16a and the internal surface 12a, in the case where the range of the degree of indentation is between 0.1 mm and 0 25 mm, with the preferred degree of indentation of -7- 0.2 mm As shown in the figure, the degree of indentation 0.1 mm or 0 2 mm is represented by an arrow 30; it is the maximum indentation along the arc 32 of the curved surface 16a, which is defined by a cord 34 For purposes of illustration, are given the measurements of the cord 34 for different indentations For example if the indent 30 is 0 1 mm, the cord 34 has at least a width of 0 52 mm. By multiplying this width by the length of the convex curved surface 16 a (illustrated by the arrow 36), it is possible to calculate the area of the contact area between the surfaces 16a and 12a, in order to measure the increased sizing area between the layers 12 and 16 Other examples: for an indentation of 0 2 mm, the cord 34 will have minus a width of 0 67 mm; for an indentation of 0 25 mm, the cord 34 will have at least a width of 0 73 mm It follows that the extent of the sizing area between the layers 12 and 16 is much greater than that of other positions characterized by simple point contact at this zone, as in the case of conventional corrugated board, which is why the present invention contributes to increasing rigidity and strength

lamellar bristol.

  The second embodiment illustrated in FIG. 4 shows a lamellar cardboard 100 comprising five layers 120, 140, 160, 180 and 200. The layers 120, 140 and 180, similar to the layers 12 and 14, consist of flat cardboard, the thickness each of these layers being advantageously between 0 3 mm and 1 5 mm (

from 0 012 "to 0 060").

  As well as the layer 16 of the profiled bristol board 10, the layers 160 and 200 consist of profiled bristol board, the thickness of each of these layers being between 0.23 mm and 0 5 mm (or from 0 009 "to 0 020") The layer 160 is placed and bonded between the layers 120 and 140 along the convex curved surfaces 160a and 160b; the layer is set up and bonded between the layers 140 and 180 along the convex curved surfaces 200a and 200b. Each set of curved surfaces at the layer 160 comprises a curved surface 160a and an adjacent curved surface b, then that each set of curved surfaces of the layer comprises a curved surface 200a and an adjacent curved surface 200b Moreover, all the sets of curved surfaces of each of the layers 160 and 200 have a height which is between 0 90 mm and 1 2 mm (from 0 035 "to 0.047"); the number of sets of each layer is between 350 and 400 sets of curved surfaces per linear meter of card stock According to the embodiment chosen, there are 375 sets of curved surfaces per linear meter at the layers 160 and 200, and said curved surfaces have a

  preferred height of 0 mm (0 039 ").

  For the manufacture of lamellar bristol 100, the layer carries the sizing applied on itself, while the layers 120 and 160 are treated by pressure means providing sufficient strength to jointly press the two layers and obtain adhesion As a result, the curved surfaces 160 adhere to the inner surface 120 a of the layer 120; the pressure exerted causes the curved surfaces 160a to indent into the surface a over a minimum depth of 0 1 mm (004 ") and up to 0 25 mm (0 010") at least. achieved, the degree of indentation is 0 2 mm (0.008 "), which increases the contact area between the surfaces 120 a and 160 a, so that the sizing area between the layers 120 and 160 increases. also, thereby increasing the rigidity and strength of the product. Moreover, the correlation between the degree of indentation 30 and the chord 34, as previously explained with reference to FIG. 3, is also applicable to this embodiment. of the layers 120 and is then welded to the layer 140, as explained previously for the layers 13, 14 and 16. During the final step of the formation of the cardboard 100, the layer 200 itself bears the applied sizing, while layers 180 and 200 are passed between pressure rollers exerting sufficient force to press the two layers together and to obtain adhesion thereof. As a result, the curved surfaces 200b adhere to the inner surface 180a of the layer 180, while the pressure exerted that the curved surfaces 200 b fit indentingly in the surface 180 a over a depth of at least 0 1 mm (0 004 ") to 0 25 mm (0 010") at least according to the embodiment selected, the degree of indentation is 0 2 mm (0.008 ") Here again, the correlations shown in Figure 3 are applicable to this embodiment In this way, the contact area between the surfaces 200 b and 180 a is increased, which increases in turn the surface of the sizing area between the layers 180 and 200, finally increasing the rigidity and resistance of lamellar bristol. Furthermore, during the formation of the lamellar bristol 100, the assembly constituted by the layers 180 and 200 is then adhered to the surface 140b, passing these layers between pressure rollers in order to obtain a sufficient pressure to drive the lamination. union of said layers and weakly embed the curved surfaces 200a into the

layer 140.

  According to the retained embodiment of lamellar bristol 100, the area of contact between the surfaces 160 a and 120 a is at least two times greater than the contact area between the surfaces 160 b and 140 a, while the contact area between the surfaces 200 b and 180 a is at least two times greater than the area of contact between the surfaces 200 a and 140 b. Moreover, the total thickness of the lamellar cardboard 100 is between 2 80 mm and 7 60 mm (ie from 0 110 "at 0 300"); in the embodiment selected, this thickness is included

  between 30 mm and 46 mm (from 0 118 "to 0 181").

  The third embodiment illustrated in the figure is a lamellar cardboard 300 comprising five layers 310, 320, 330, 340 and 350 The layers 310, 320 and 330 consist of flat cardboard, the thickness of each of them being between 0 3 mm and 1 5 mm (from 0 012 "to 0 060"),

  as in the case of the first two achievements.

  The layers 340 and 350 are executed in profiled bristol board, the thickness of each of them being between -0.23 mm and 0 5 mm (from 0 009 "to 0 020") The layers 340 and 350 are put in place and glued at each of the layers 310, 320 and 330 along the convex curved surfaces, as previously described for the embodiment illustrated in FIG. 4 Moreover, the curved surfaces of the layers 340 and 350 have the same characteristics as those described for the realization of the FIG. 4 and they are identical in all respects, except as regards the direction of the curved surfaces of said layers. In other words, in the embodiment of FIG. 5, the curved surfaces of the layer 340 extend in a first direction, whereas the curved surfaces of the second layer 350 extend in a second direction, oriented perpendicular to the first, to form a cross-crested lamellar bristol, because of which the resulting lamellar bristol is lighter in weight and has smooth outer surfaces Furthermore, since the grain of the layers 340 and 350 has different directions, the overall grain direction of the card stock is more uniform and

better balanced.

  If the present invention has been described and illustrated with reference to embodiments comprising one and two inner corrugated layers, it is however understood that the scope of the present invention also allows the placement of three or more corrugated layers.

  as previously indicated.

  In order to illustrate as clearly as possible the superior lightness of the lamellar bristol forming the object of the present invention compared with solid lamellar bristol, we will give two examples. In the first example, the comparison is made between the 100-point solid lamellar bristol. and the embodiment illustrated by FIGS. 1 and 2 of the present invention. In the case of 100-point solid cardboard, each of the three layers has a thickness of 0 85 mm and a weight of 551.4 grams per

  square meter (g / m 2), giving a total weight of 1,654.3 g / m 2.

  According to the present invention, the 100-point card stock consists of two flat outer layers 12 11 - and 14, each of which has a thickness of 0 71 mm and a weight of 463 g / m 2 The shaped inner layer 16 has a height of 12 mm, but a thickness of 0 30 mm only and a weight of 209 8 g / m 2 approximately As a consequence, the lamellar bristol forming the subject of the present invention weighs only 1 137.0 g / m 2 compared to the weight of 1,654.3 g / m 2 of solid lamellar bristol, which represents a saving of more than 31% of the amount of cardboard used to obtain in practice the same characteristics of stiffness and strength of the board.

lamellar full.

  Another example makes it possible to illustrate this economy even more clearly. Lamellar bristol is 172

  points can be compared to the realization of Figure 4.

  Typically, the 172-point solid lamellar bran has, independent of the number of sheets constituting it, a weight of 2,854.8 g / m 2. According to the present invention, the 172-point bristol board consists of three flat layers, 140 and 180 each having a thickness of 0 71 mm and a weight of 463 g / m 2 The inner profiled layers 160 and 200 each have a height of 1 12 mm, but a thickness of 0 30 mm only and a weight of 209, Approximately 8 g / m 2 As a consequence, the Laire Bristol board which is the subject of the present invention weighs only 1,810.5 g / m 2 relative to the weight of 2,854.8 g / m 2 of the cardboard L Solid mass, which represents a saving of more than

  37% of the amount of cardboard needed.

  In any case, it is understood that the inner flat layer 140 may be thinned more than this thickness of 0 71 mm, whereupon the saving in weight

would still be superior.

  The foregoing description admits a number of

  modifications, changes and replacements; in some cases, only some features of the present invention can be used without using the others. It is therefore useful to

  to broadly understand the claims set out

  together according to a point of view consistent with the spirit and the

scope of the present invention.

12 -

Claims (2)

R E V E N D I C A T IO N S   1.Light lamellar bristol, characterized in that it comprises: at least two layers of flat cardboard (12, 14) having a thickness between 0 3 mm and 1 5 mm, the outer surfaces of these two layers (12, 14 ) being flat and smooth; and at least one inner layer of profiled bristol board (16), the thickness of which is between 0 23 mm and 0 5 mm, comprising ridges (16 b) and valleys (16 a), placed and glued between inner surfaces (12a, 14a) of each of said two layers of card stock, said crests (16b) and said valleys (16a) having a height of between 0.90mm and 12mm; said profiled bristol inner layer (16) having a number of sets (18) of ridges (16b) and valleys (16a) of between 350 and 400 per linear meter of cardboard; and in that the convex curved surfaces (16 a) of at least one of the faces of this inner profiled bristol layer (16) are indented in the inner surface (12 a) of at least one (12) layers of flat cardboard, for example to a depth of 0 1 mm, in order to increase the surface of the contact zone and the bonding zone between these layers, and this in order to finally increase the rigidity and the resistance of this lamellar bristol. 2 lightweight lamellar container according to claim 1, characterized in that it comprises a third layer of cardboard with a flat outer surface (180) and whose thickness is between 0 3 mm and 1 5 mm; and a second inner layer of profiled bristol (200), the thickness of which is between 0 23 mm and 0 5 mm, and incorporating ridges and valleys, placed and glued between the inner surfaces (140 b, 180 a ) each of the second (140) and third (180) layers and whose height is between 0 90 mm and 1 2 mm; and in that said second inner layer 13 of profiled bristol board (200) has a number of ridges and valleys which is between 350 and 400 per linear meter of cardboard, the convex curved surfaces (200 b) of at least one face of this second inner layer of profiled bristol board (200) is indented in the inner surface (180 a) of this third layer of card stock (180) to a depth of at least 0 1 mm, in order to increase the surface area of the contact zone and the gluing zone between these layers, all in order finally to increase the rigidity and the resistance of this lamellar bristol. 3 lamellar lamellar according to claim 2, characterized in that the ridges and valleys of the first inner layer of profiled bristol (340) extend in a first direction, while the ridges and valleys of the second inner layer of Bristol board profile (350) extend in a second direction disposed at 90 degrees to the first direction, thereby forming a crisscrossed cardboard where the grains of said first and second inner layers are balanced (340,   350), arranged between them at 90 degrees.   Lamellar billet according to Claim 1, characterized in that the inner profiled bristol layer (16) or each profiled bristol layer (160, 200, 340, 350) has a number of 375 sets (18) of ridges and valleys. per meter linear of Bristol.   Lamellar container according to claim 1, characterized in that the surface of the contact zone (32) between the inner layer of profiled bristol board (16) and one (12) of the bristol board layers with a flat outer surface is larger the surface of the contact zone between said inner layer of profiled bristol (16) and the other (14)   said cardboard layers having a flat outer surface.   Lamellar container according to claim 5, characterized in that the surface of the contact area between the inner profiled bristol layer (16) and the one (12) of the outer-surface bristol board layers is at least double the area of the contact area between said inner layer of profiled bristol (16) and the other (14) of said   layers of cardboard with a flat outer surface.   Lamellar container according to Claim 1, characterized in that the total thickness of this lamellar bristol is between 1 5 mm (0 060 inches) and 4 70 mm (0 185 thumb).   Lamellar flake according to Claim 1, characterized in that the total thickness of this lamellar bristol is   ranging from 0 080 inches to 0 120 inches.   Lamellar container according to one of claims 2 or 3,   characterized in that the total thickness of said lamellar bristol is between 2 80 mm (0 110 inches) and 7.60 mm (0.300 inches).   Lamellar container according to one of claims 2 or   3, characterized in that the total thickness of this lamellar bristol is between 30 mm (0 120 inches) and 46 mm (0.180 inches).   Lamellar container according to Claim 1, characterized in that it is used for the manufacture of book cover inserts and bindings of loose sheets, light in weight, but having the required stiffness and strength characteristics, in addition to surfaces smooth exterior.   12 lamellar Bristol according to any one of   1 or 3, characterized in that the ridges and   the valleys of the inner layer of profiled bristol board (16) or of each inner layer of profiled bristol board (160, 200)   have a height of 0 mm (0 039 ").   - 13 lamellar Bristol according to any of the   Claims I to 3, characterized in that the surfaces   convex curves (16 a) of one of the faces of the inner profiled bristol layer (16) or each inner layer of profiled bristol board (160, 200, 340, 350) are indented in said bristol board layer (12; , 180) with which it is in contact, to a depth of 0.2 mm (0.008 ").   14 Bristol lamel Laire according to any of the   Claims 1 to 3, characterized in that the surfaces   convex curves (16 a) of one of the faces of the inner layer of profiled bristol board (16) or of each inner layer of profiled bristol board (160, 200; 340, 350) are indented in the bristol board layer (12; , 180) with which it is in contact, on a depth up to 0 mm (010 ").