BE620902A - - Google Patents

Description

       

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 fM6 << M and device! manufacture of cardboard on4u1 ', and product * thus obtained, "
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 : The present invention essentially relates to a method of tabzo1.t1t: l.0l1 of corrugated cardboard walls 8I1U.p18 '. of S.tU'8 -'pay or very thick * comprising at least two and preferably three layers or thicknesses of corrugated interlayer "
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 with three or four smooth sheets of coating, as well as
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 the products obtained by this process and certain means dewtina has their shaping. the corrugated spacers are thus interposed or put in eandricb. between these coverings spaced

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 - which are made up of flat or smooth excavations fixed by gluing to the tops or ridges of the undulations of the corrugated spacers in order to constitute a complete product.



   In particular, the triple-walled product has the advantage over other cardboard materials, when they constitute boxes, of having a high resistance to buckling, by compression, and, therefore, of allowing stacking. '' a large number of boxes on top of each other when they contain heavy objects, without producing excessive buckling or cracking or total collapse of the vertical walls of the boxes near the base of the stack * Another advantage is that this product offers great resistance to the tearing penetration produced by sharp objects which strike it, which,

   may occur when the boots are transported or subjected to negligent handling *
The high buckling resistance is obtained from the fact that the flat covering sheets are very widely spaced from the neutral axis, while the tear resistance is duo to the presence of multiple layers of material * However, these properties are not achieved at to a high degree that after the ridges of the corrugated backing corrugated spacers have been securely bonded to smooth trenches or coating pianos through the entire structure of the final product.



   To manufacture the product, a flat coating web is attached by adhesion to a core formed of a corrugated interlayer by means of an adhesive substance or glue applied to the tops or crests of the corrugations or grooves, over the entire width of the glue. - here which are parallel between aliases, in order to constitute a layer called corrugated cardboard with one face. One repeats this soft operation or three times, according to whether one wishes to obtain a corrugated cardboard with double wall or tripla.

   Then these single-sided boards are heated to put the sheets in

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 state of receiving the glue and the exposed crossings of the OD4u1c- tiona, on the unrevoted side of the corrugated element of each of the two or three coats, receive the applied glue. = their entire width, after which these two or three coats. are
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 superimposed and compressed 10 together with a third or fourth coating excavation placed on the outside, in order to
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 that said crêtos dooditea undulations are made integral with the coating sheet of a layer n4, acont. as well as said third or fourth floor excavation.

   While pressure is continuously applied to the composite board thus obtained, the latter is heated in order to partially dry it and to bind the various sheets together, these digs thus incompletely.
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 hardened. In triple-walled corrugated oaxton water, this heating can preferably be carried out at a temperature between about 149 ° and 16 ° C. The composite board is then cooled to allow handling.
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 after which it is optionally grooved or folded transversely at the corrugations to allow the folding or bending of the product to give it a packaging shape, and, optionally locally crushed, trimmed and cut at its ends.
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 final dimensions.

   All of the aforementioned operations can be carried out manually, = 4o they are, generally carried out more conveniently while the head continuously scrolls, with the corrugations arranged transversely to the path of the displacement, in a valley through an automatic machine h making the corrugated cardboard which comprises two or three sections for producing the one-sided corrugated cardboard, followed by a double-sided device which comprises a laminating section, a heating bag and a cooling section, thus

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 a section for creasing or stamping plies and a shearing section,

   The relation between temperature and speed of advance varies depending on the humidity, thickness and porosity of the sheets, in order to obtain a residence time in the heating section sufficient to set or harden. the aforementioned glue. Thus, for example, the triple-walled corrugated board board can be heated for at least fourteen seconds and at most 24 seconds (otherwise the product may be burnt).



     The material which constitutes the dividers and which is inexpensive can be paper of any origin or even be crystal paper. However, in the manufacture of shipping packaging containers, the sheet is generally made from paper produced by the Kraft process for treating pulp, paper made by the semi-chemical process for treating pulp. , paper made from waste paper, or paper made from the reduction of straw to pulp.

   The covering sheet, which is relatively expensive, can also be of paper of any origin, but is generally made from kraft paper from any source or from a scrap made as a raw material from waste paper.



   The role of the glue is to make the interlayers adhere to the coatings As the machines used to make corrugated cardboard operate at a relatively high glass, the glue must adhere or at least set or harden immediately.

     When a glue has set, it undergoes either a physical or a chemical change to such an extent that the materials between which it is bonded.

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 found to be stuck together enough that they cannot easily separate * Physical or chemical changes
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 The latter only serve to develop the binding force in the glue. This latter period is a period of binding establishment or strengthening.
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  The present invention relates to a process for manufacturing corrugated cardboard with multiple walls p9 * u4 "having increased rigidity and strength and preferably belonging to the triple-wall type. This process is noted.
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 Quable in particular in that it includes all other operations known per se, the operations consisting in stretching the above-mentioned sheets of do rotomont from one end to the other, by stretching it in order to maintain their fullness positively throughout the entire process. manufacturing process to nssemblor the component layers druao their freshly made and wet state with all the glue that has been set in place, pressing them simultaneously, continuously and firmly, where1l.

   while the covering sheets are held taut and any relative slippage of the component elements relative to one another is pocketed, the moisture - but not all of it - being gradually removed in a substantially uniform manner by heating, to cooled! ' the composite board thus obtained while it is still '
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 under tension, and, immediately afterwards, to crease or possibly p11sIur said board follow the requirements of the subsequent folding, while there still remains a certain humidity,

   and finally & possibly stacking the finished product seam to the desired dimensions for a period of establishment in order
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 do allow residual moisture to evaporate and to. components of said board to eventually acquire a stabilized moisture content with respect to the moisture of '

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 the ambient atmosphere.



   It is surprising to find that when the triple wall product is manufactured in the manner described with a total weight almost the same as that of the double or triple wall products previously known, the former exhibits such a higher strength, which prevails that the item either hand made or in a corrugated cardboard making machine. As to the values of temperature and temperature, they both vary within very wide limits.

   The great resistance of the new triple-walled product thus obtained is due, for example, to the fact that the excavations are kept taut so that they remain absolutely wound laying the whole of the procossus, without any relative sliding between any parts of 1. together, which could spread the freshly applied glue or break the continuity of the glue of the previously glued parts.

   Furthermore, if the finished product is to be creased or creased to allow folding of flaps or the like, it should be done immediately after the cooling phase because at that time the product still retains some moisture loss and , although the glue has already set, it is still slightly flexible, which facilitates the crushing which forms the stamped fold lines or bands without appreciable damage to any layer of the assembly or to the glue connections,
The result is a product exhibiting a balanced structure and the constituent elements of which are firmly linked.



   Instead of using the relatively heavy paper coating pits, which are employed to make the previously known single or double wall products, the triple wall product, obtained by the process described.

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 ci-dosuus, is enormously stronger, in all respects, than the double-walled product, although the weight of the coating digs of the two products is about the same. In
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 in other cases, the triple wall product can be made with troughs of thinner or lighter rollable paper.



   The glue used consists mainly of starch and water which must be heated to a temperature high enough to gel the starch, but a silicate type glue, such as sodium silicate with water, which must be heated to evaporate
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 turn off the water and let the glue set. Thus, in mild cases heat is required.



   It is not * very difficult to send each
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 heavy to glue at the time of simple dig. corrugated intorco.la1ro is applied on the single layer of coating or smooth sheet. However, serious: p: ro1rlemes arise,. when an attempt is made to impart the adequate amount of heat to the glue after the various coatings have
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 been combined to form the crossed layers of corrugated intorDla1ro and the four layers of covering or smooth sheets,
Such problems become even worse if the excavation of the coating used is thicker in order to confer
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 to the finished lino product greater resistance to flanbago as well as better resistance to tearing or,

   if the corrugated spacers are made with large or high
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 corrugations to further remove the excavations from revotomont as indicated to increase the resistance of the flame by removing the excavations of coating more of 1-lax neutral. The two outer covering sheets are

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 preferably of a heavier weight than the covering sheets.
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 all internal, to obtain the highest possible moment of inertia. Thicker sheathing sheets absorb more water when the glue is applied and their inherent thickness reduces their ability to conduct heat.

   Higher corrugations contain more air, which reduces the flow or the. heat transmission ot further away the cover sheets and glue away from the heat source which can only be applied.
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 one side of the combined element linkage, when any cocuaode manufacturing process is used.



  If excessive heat have been applied to one side of the combined coats in an attempt to achieve sufficient
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 of heat to the far side, then there is a risk of glue on the high side of the vicinity of the heat source.
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 Cements desired and deviate from the normally desirable form or configuration of the adhesive substance when placed between the parts which it is to join.



   However, it is observed that the usual methods for attempting to manufacture this corrugated cardboard with triple wall ot resistance
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 increased are doomed by oux-menea to failure.



  According to the present invention, it is possible
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 to manufacture in a practical way corrugated cardboard, multiple walls, note: .1 The triple-walled type of which the minimum resistance is greater than that of similar cardboard known and produced with the 1.101.10 total weight of the coated sheets - moun or smooth sheets, distributed between only three sheets liasos do revôtomont and only two araeo or wavy spacers placed between them and whose resistance

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 maximum this considerably higher than that produced known.

   Cola is not obtained by using foils of: outer surface or smooth excavations on paper not bouemnt of heavier weight but, according to another feature of the invention, one also employs rov6to oat excavations. do very high density obtained by the use of strong paper.

   grille mount,
Moreover, according to yet another characteristic of the
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 In the present invention, the manufacture of the single-sided separate layers comprises the operation of lining the crest of the corrugations of the corrugated interlayer, which must be attached to the sheet to be covered, with a collo composed of tnç = ba ensuring the taken at relatively high temperatures}
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 thus, when fixing the individual excavations do revoteacnt a glue either based on starch or based on silica is used.
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 te, which requires a large amount of heat to cure properly and, therefore, can withstand the rework at higher tomperaKtree 'in an efficient manner.

   The use of a glue of this type is practical due to the fact that at this stage of manufacture, the supply of heat to the glue does not pose any major problems,
Next, another feature of the invention is, when the various single-sided layers, for example the three single-sided layers composed of a corrugated interlayer and a covering sheet are subsequently juxtaposed or joined by adding a sheet of additional outer coating, for example, a fourth coating sheet which is necessary to form the finished product, a glue is used which can also be either starch type or
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 silicate type, which is composed so that it tees Fut .. at lower temperatures.

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   The resulting advantages are that, although the covering sheet has a high weight and strength due to being highly calendered, its high density and relative thinness allow heat to pass through it more easily. In addition, when performing the final assembly operation, a large amount of heat can be passed through the product to cure the glue requiring a lower temperature to cure this glue in a satisfactory manner without summer. - improve the previously applied glue which hardens at higher temperatures,
According to a principle well established in mechanics,

   the greatest resistance and rigidity are achieved in a construction element formed from a determined quantity of natiero by arranging the surfaces subjected to the forces in such a way that they are as far apart as possible from each other in order to obtain the moment of highest inertia. Consequently, it is known to separate the covering sheets or smooth trenches as much as possible from each other, and, in the case, for example, of a triple-walled board, to use corrugated spacers of which two are made with relatively tall waves while the third is made with lower waves.

   Then, according to another characteristic of the invention, the elements are combined so that the undulations of lower height are closest to the heat source used to take the glue necessary to join the different sheets of the material. final product. It follows that the heat has not traveled a great distance before reaching the first zone where the glue used during the second operation or general assembly phase is located. At the same time, all the layers are found rather widely removed from the axis

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 neutral of the. product material.

   Finally, the cardboard boots made with the aforementioned cardboard are easier to manufacture and use.



   As a further and preferred development of the invention, the adhesives applied during the general assembly operation also differ from one another in their characteristics. Those which are applied to the tops of corrugations which are closest to the heat source can be prepared to set at temperatures some lous higher than that of the glue used to attach the tops of corrugations which are. away from the heat source. So,

   the greater amount of heat which reaches the glue closest to the heat source has even less tendency to damage the glue, while the slam * which reaches 4 the glue farthest is clean 4 make this glue set *
The facing sheets are preferably as already stated above revised from pure, highly calendered Kraft paper, which is of high density, but different weights in various layers.

   Thus, according to the. Previous practice, the most gentle exterior digs can be performed on very heavy paper, while the two intermediate coating digs may be performed on paper plus housing. This has the great advantage that, on the one hand, the thicker layer which is closest to the heat source, receives its heat directly, on the other hand, the glue located on the inner side of the coating pit at the same time. farther from the heat source receives heat without it passing through the leaf, and,

   finally the soft intermediate coating excavations are both made on paper

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 lighter and therefore thinner which does not offer as great a resistance to the passage of it. heat.



   Another feature of the invention is the use of a type which can be heated to elevated temperatures prior to its application to the peaks of the mountains.
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 undulations back interlayers ondulas, in the case of the omr- blaga of all the elements to make a structure to
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 triple wall. Such a glue may contain 4% of the composition containing ngr, ndo part of the sodium silicate, starch, clay, water and other additives. Starch acts on some Bort;:; coraraa djoi3ic agent, -ttoîro or dehydrating agent whereas, by convoraion or gvlt1ni8tion under the effect of heat it aboorbo oau lrt.ias60 by lo oïlier-tu do 00- dium.

   Lao silicate; sodium 00 fridge obviously when we eliminate * a certain percentage of water (for example entro
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 l3r5 - and 15? *>.



   In fact, all of the glue is located on the ripple tops and the pianos coating excavations, and no part of the glue has the property of uno
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 colla which was first hardened and then rvcau1llúo, oo that so would produce whether dos single or double wall elements prepa-
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 Avanco res were subsequently assembled by manual processes using fresh glue of which 1 o.u would necessarily soften the previously hardened glue.



   The present invention enables the rapid manufacture ot
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 efficient of corrugated cardboard with triple wall of gr-Jido strength mLm4 when loo sheets of exterior rcvttro0nt or excavations pl.n, .a or liE3> -s Of which made of pure Kraft paper known as iiipuni6-blc or proof da l ' humidity, and even if the corrugated interlayer was made of thicker paper than the usual paper for the purpose of:.

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 solidity of the final product, as will be demonstrated below.
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  Another object of the present invention is to provide a creasing or creasing device for multi-wall corrugated cardboard. We know about devices that
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 include bare minus a pair of rollers or do ex: lott08 to ruin or rotary plia stamping placed one look and
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 ontre which is pulled the plche tormindo, these molottos forming one a malo tool having one cuts tr "nevoMOlo a donut forming punch of profilago or .forming ot
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 the other - a female tool preontant in cross section un- evido1. \. Int corresponding forming motor,

   The device do rr.1no.o follows the invention is rrrasrqzt ^ b7.a notnanont we oc that said malo tool this suporpoed to said fcoollo tool in order to be carried from above on the back face = do In the above board, the part protrusion <5o forming a convex profile arched all around its pi5riphdrio, of a width of about '! 9Rm, and a height of about 5nua, while the aforementioned Óvidomont around- In the p) Sriphdria of the fonollo tool pr6oit6 which oonatituo the impression soniblomont ax4.ct "of the malo tool has, its dimensions corresponding to the glues of the male tool.



   The present invention also relates to new industrial articulo titra the corrugated cardboard product with multiple walls, manufactured following the process set out above in its outline and comprising several layers of inter-
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 corrugated calaries ^ .lternot with back excavations binding of coating the weight of which is greater for the outermost excavations than that of the excavations constituting the layers
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 interior,

   Looqiollos are by conl6nt relatively higher mincoooai produced this remarkable particular in 00 that the aforementioned coating sheets are all of the same density

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   very high and preferably made on pure Kraft paper with strong calender, ot which are all assembled with the aforementioned corrugations, on one side have corrugated spacers by at least one type of glue and on the other side by at least one other type of glue, the glue being confined in the parts to be joined and being resistant and free from the effects of overheating throughout the product.



   According to another very important feature of the present invention, the aforesaid multi-wall corrugated cardboard product has corrugated spacer backs of relatively very heavy weight, joined to sheets of wood, some of which are less than one weight. a relatively small heat exchanger
Indeed, the present invention recommends the use of heavier corrugated spacers with the aim of increasing not only the compressive buckling resistance that the finished cardboard can withstand,

   but also its resistance to puncture by sharp objects during transport. It has been frequently and emphatically pointed out in the known art and in the present day in practice, that the strength of the corrugated cardboard composes, except as regards flat crushing, depends entirely on the strength of the coating or coating. smooth digs, and the only role of the corrugated spacers is to space the coverings enough to move them away from the neutral axis of the board, in order to obtain maximum strength from the cardboard board.

   The weight and thickness of the corrugated interlayer have heretofore been considered unimportant in their contribution to the strength of the assembly.



   It has been found, on the contrary, that the weight and thickness of the corrugated interlayers contribute in a marked way

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 to increasing resistance, especially puncture resistance. This increase is so weak that the increases in resistance due to small increases in weight and thick end of interlayer are more than sufficient to compensate for the potential losses due to a significant decrease in weight and thickness of the excavations. da coating,

       Typical test results with respect to compression, buckling and perforation are shown in the accompanying Table 1 for various three-wall corrugated cardboard structures. It is evident from examination of the table that an increase in the weight of
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 leaves do revoterai results in a; tucattati do the resistance of the plancha, co result being consistent red
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 triourc experiences.

   Examination of the N. 1 cardboard sample shows that respective increases of 21% and L?, 5 in the weight and thickness of the excavation excavations compared to those of the K sample 2, so results in an increase of 7% do in, resistance h. the perforation of the board and an increase of 5975% in the compressive strength of the board. The variation in the total paper weight is 14.5%.



   While past experience indicates that the increase in weight and thickness of the interlayer no contributes to the compressive strength of buckling and does not add
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 nothing â resistance to. '10 .. perforation, examination of samples 2 and 3 shows that the increase in the weight and the thickness of the interlayer 0 (,, \ 11 in the sample 110 3 # respectively do 27 ei ot of 20 y compared to those of the sample N 2, entails an increase of 17.5 - do the
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 puncture resistance and compressive strength 10. The variation in total paper weight is due to 8.

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  In addition, the comparison of the samples t at 3 shows that, small in the respective decreases of 1.3 96 t of the 9.5 of the weight and of the thickness of the fjuillca do rovotomont do 1 i cchax.t311on a 1, decreases which may Otro considered important, a real increase in puncture resistance and 4 in compressive strength was obtained. It is important to note here that 108 respective increases in weight and thickness of intoral-s ondulas, 27 ruz ot do 20; for these samples, not only compensate for the loss of resistance to the reduction in weight and the loss of rovfitemont hardwoods, hand increases the resistance of the absorption of the plan-
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 che. The variation in the total weight of the plancha translates into
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 a decrease of less than 6%.



  Sample 4 is included as a result of tibloru 1 to indicate that the use of excavations must be carried out by weight and by internal thickness DO translated as dos value of inter resistance.
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 mediators. This might be expected from the previous paragraphs.
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  In normal factory production, where cardboard and made using exact glues are similar to those used to make the paperboard described in Table I, and where similar grades of paper are used which will not be produced forcibly. back m! '1cs rolls, it was found that: these qualities of cardboard exactly similar damn glues indicated for sample n02 of table I can see a resistance to ire pcrfort'.tion which varies from a NiniNua do 28, 35 kcm per meter: do d4uhiruro to a maximum do 31.86 kom while the resistance at 1 ^. compression could vary from a maximum of 2321 k-dm to a maximum of 2857 kg / m.

   From industrial production cardboard, exactly scnbl, blo to the rprson-

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 te per sample 3 of Table I, but for the customer's puncture resistance of a minimum of 32r32km a maximum that exceeds 36Skm as the compressive strength of a nin1. mula do 2500k &! tt to a naxicn1tl do 3572kg / m.



  The increased puncture resistance of the use of heavier or thicker corrugated spacers in three-fold corrugated cardboard is all the more remarkable when observe it in the light of practice
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 passed in the case where oll.o viso z. meet the minimum nomos required for the corrugated cardboard Ion nomes niniaalos for the corrugated cardboard boxes are set out by oxonplo dnna rule N 41 of the U, S, Unifom Proi ± ht Classification.



  (Uniform Classification for Frot in the United States of America) 6Co specific regulation that each quality of cardboard must meet 4 uno value ninit1 .. 'Ù.o of resistance to bursting or puncture. In 10 cases of certain cartons, the resistance to 3.tSClwfeCGXIt or to puncture, measured by the Uullon or Cndy test, exceeds the capaci-
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 ty of the testing machine used to carry out the test. Under these conditions, a perforation test (Boach test) is used.

   Although the soft trials are not identical, the results are comparable because the unit do Meure do
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 perforation per kilogram per meter of tear was chosen to correspond to a burst mosure reading.



   In an attempt to meet the specifications of the regulomont
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 N 410-Lil is common practice to determine only the rtsistrncos at lttc1: .ttnt back leaves do revoteacnt and to incorporate in the finished carton back do revoteacnt excavations whose total burst resistance is equivalent to the

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 dcairoo burst strength for 10 finished carton. We
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 therefore completely ignores the corrugated interlayer. For example, if you want to obtain a 4 double wall cardboard
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 with a reduced resistance to the test of 17.01 knu do tearing, the excavations will be chosen so as to be revised. sum of their individual values of resistance to 1. ' dclata- mont is 17.01 k (n / ra, No account is taken of the wavy intovcnlairc.



  Conveniently, when this employee of triple-wall cardboard, leads to errors of a considerable magnitude. In the case of Sample 2 of Table x, a burst or puncture resistance of 16916 lcgm / m 8oulo Which could be very predicted. There is still a lot of néthodo no pourrr. jr..u. ^. is Inisser predict that with a net decrease of 21 r. from the weight of the recvétomont sheets, it is possible to obtain a lugwont1on of the resistance to the lontlont or the perforation.



  The incorporation of the heavier corrugated cardboard into the triple-walled corrugated board, while the weight of the smooth or flat excavations is reduced at the same time, presents a second important aspect for the consumption of the manufacture of the As indicated above, the transfer of chr-lour to the uppermost glue line, during sctlbl operations: 18o as shown in Figure 2, is both difficult and critical. Any arrangement of sheets of the rovetcncnt of intorcalairos or intervals
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 air between these which might facilitate heat propagation to the upper sizing ligno is desirable to facilitate the carton making process.
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 conpose.

   Heat propagation through corrugated cardboard

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 This is effectively facilitated by the eicultand use of thinner do rcv6toacnt sheet and more corrugated spacers.
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 thick, heat passes through the cardboard mainly
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 according to two modes, namely by conduction and by thermal insulation created by the vapor of the contnntc, the vapor dtot% u evidently Óf.1MO not suulonont of the glue which is in the process of drying out .c ni3 also of a-surplus of humidity which this content dzne fouîllo as a result of the asaonblago of the excavation due to rov5to: ion, t and dQ the interlayer to form a section, .nt h a
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 :race.
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  The quantity of heat which propagates through the plan- cho by conduction ost dctcminco by the following relation
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 Q = -4 .... L (1) R
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 where Q ddsiSf10 Here quantity of heat truncated! ("6 t the dïttd- * ronco do temperature existing through the ech, mtïUon ot * R this the rÓa1stoo opposed to the heat flow, the resistance R is ddtornln <5o at in turn starts the relation 2
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 R = L (2) k A
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 where k denotes lr. thermal conductivity of the material, L this the thickness of colui-ci and A is the eurfco expos60 to the. heat source. Bruis all r3atri.a, u at couchas multiplqup in r <5si3tance at the trcnefurt of chnlour is 1 80r1t1O dos rCsist-1.t1coa Individollos.

   Therefore, the heat tl'N.18- fsrv to trtsvors in ti,% t6ri:% u to layers u.t3plcx tol than an onpton. corrugated is supplied by 2 Lcuaïvn i
 EMI19.10
 Q = - ##. T. # - (3) z or R1 + R + R3 + ...



  Q = ---- A a 1 --------- - (4) il; [, 2. L- k, k2

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 EMI20.1
 By reducing the thickness of the excavation do coating, In quantity L in equation (2) oat decreased, which untr1no, son. If the resistance R decreases, the equation (t) increases the amount of heat transferred through the board. It should also be remembered that the increase due to the thickness of the corrugated interlayer has the opposite effect. However, the total decrease due to the reduction in the thickness of the excavations of the forest and to the increase in the thickness of the the 6pa1oaour dos întaroclrirce ondulas s4 results in a marked decrease in the overall area of the cardboard through which the r. heat must be YÓh1cu.léo.



  The use of int.;: Rcâ1t: rca ond'.1.lea plus 4pais also helps the reduction of the gas or vapor layer between our excavations at rcv8teoont and loo tsrC.niro, Colrv is due to the fried that the beginning in a fawn divides the undulations of a height determined which no more than light: raont affoctdo by the corrugated interlayer. If lr. cross section and, therefore, the volume between the intoral faces of the excavations do rovttaDont thus remain constant, it is obvious that intorctÙ "\ iros wavy more 'pays will occupy im voluno more
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 large, thereby reducing the volume of steam and, consequently,
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 quent, its effective thickness. This decrease in thickness
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 do the layer of air so translated in turn by a transfer do
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 heat more grcuid by conduction.

   The total amount of heat transferred by conduction is between 3 and 4 fart L0 flow of water and air rising through the cardboard board constitutes the second main uoyon by which the heat was trejanferéo through 00 cardboard. The part of the current formed by the heated air will transfer heat to the glue and to the constitutive dleoenta of the cardboard which are loe more ú10iC! 1 ": S from the source of heat,

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 EMI21.1
 by sensitive halour door. The vapor transfers non-ocular heat by means of 8cns1blu heat port, W4 also by repeated condensations and 4vaportions.

   Any- liver # the lookout produced by case dvrnièra is low, The percentage of air in the úcou1omont mixto augoonto k Lam = that the vapor will ront- through the pl <mch0t of ott raultt 'Un1) decrease in pressure prvrtiellô do the steam of stai. So, the vepour water ost r.m1ntonuo mainly aous t01'f1O da steam and transfers the chalou? by heat door 80n6ibla
 EMI21.2
 or by overheating,
 EMI21.3
 Coono lo tronafort of heat ost from asaont1011oÓnt to a current of vcpour, the quantity of heat tr, - nofdr6o depend on the quantity:

  '.nt1t & do vapor which is capable of notOï * through the interstices of the constituent elements, the passa-
 EMI21.4
 go of a fluid through an opening quolconquo est
 EMI21.5
 determined by a form of the genre do la forr..1Ulo do POUElu1l1.o
 EMI21.6
 a 32, p, V (5) dl go D 4
 EMI21.7
 We can see that everything:. Its things could be removed elsewhere equal to, the volume of fluid 14V ", capable of doing trnvor8: 'an opening do d1 ::>. Metro D, is inversely proportional to the length L of this opening <Next ln . present invontion, 11pploi intorcnl1ro8 plus lp:

  -.1s, in taupe side, the use of roast leaves.
 EMI21.8
 are thinner, resulting in a marked reduction in the thickness of the paper contained in the final composite board.
 EMI21.9
 (see Table 1), Thus, there is a marked decrease in'lct
 EMI21.10
 length of the openings, resulting in a greater flow
 EMI21.11
 dtcoulomont do steam, ot uno more gynnds quantity of heat
 EMI21.12
 transferred.
 EMI21.13
 It fnut úg: .üotlent 1 take into account the ^ ctaur "1" "which

 <Desc / Clms Page number 22>

 
 EMI22.1
 ropr6c., nto the dinmètro do Ilouvoxtaret dree equation (5) which, against that the qU "'I'1tt tv of steam this dirootor.1ont proportional to the aaxrS of the Sun:'. t1ètrc of the opening, In the $ r6sctttto invention, we used excavations of donfios pz coating, 4- are of potits interstices.

   In addition, the intorcalniro ondula is porous, because it takes more intGr8t1oo more rumbles Thus, not for an identical thickness of the whole ac la plancha the flow rate of vnpour sornit 1lîC'.x: 1u: \ 1. ni l'Ópn1ascu.r des Intorccl: - .. ir \} 3 ondulas roprv8vntf'.i t a higher contagion of the total pinnacle.



  Llexpmon du tqblcnu I reveal that Ion întorcalairoo ondulas represent 26% of 3. ' ep: '. total isnour of p-.picr ânjte l'cchaa- t1l1on 1, to comp :, rf.r to 32 eQ, of uchnntillon 3. Therefore, the total effect produces 1': '. 1 "I * c'pc.i3sour ot In porositd gives: an ocroi:": scf..mt do thoroic transfer do 5 to 6% # or a total value: '. 1o overall, including conduction do 8 to 10 5 The present invention relates to the cost of triple-priced corrugated board.

   Ln cOf.1p: -. R: '!. ison of ech3J: 1t1J.lons 1 and 3 of tblû: -' u 1 shows that one can obtain a corrugated cardboard of resistruxeo more scolding by using ïn. tcrclniros ondulis more dpnis and excavations do revttemont more mincest ci '\ lgrv5 lv that there is n. however, reduction in the total weight of paper d, -, nj3 the produced When the cardboard is purchased by weight, the use of paper of more weight Íc.1blo 1Qp11 which c-empties a deononîc iaportnts. This ucononio is -cplifidc when rnppollo the price of the ink :: .- In1ro corrugated this interior to clui do In fo'revttenont.



  Thus, with the prsontq invention, one substitutes them for sheets of high cost, intorors at low cost, with a reduction overall. of the total weight "". 1 which results in

 <Desc / Clms Page number 23>

 
 EMI23.1
 significant savings.
 EMI23.2
 



  In summary, it has been established that a deporting increase in resistance and thermal stress as well as substantial savings can be atrocious when 10
 EMI23.3
 weight and thickness of the back interleaves undula are respected! -
 EMI23.4
 voucnt 161g / m2 ut do 0.30 oz, and when the weight and thickness of the spacers vary from t46g / o and 0 # 26 #, respectively, to the corresponding hoppers bed. ltintoro: 1l.ni: ro the heaviest and Io more 6piS which one can undulate in practice.

   This ducouvcrtc is a contradiction di recto avoo ln literature and 1 ". Technique ruitdrioures rolativ3a nu carton ondula nom"! ut nux structures of oiduld cardboard more
 EMI23.5
 heavy. '
 EMI23.6
 Other goals, in particular and in advance of the pre-
 EMI23.7
 in the course of the description which
 EMI23.8
 following, by referring to nux draws achL4tiquJs anxés given only as a non-illustrative example and illustrating a dodo of rlistion of the invention, Dr-na drew them the figure 1 represents a view of eÔt-5 pirtiollo on elevation of a section of a machine producing corrugated cardboard 16 on one side on a corrugated cardboard fo.briot1on does not have the operation in which the interclniro ondula is applied on a sheet of corrugated cardboard - figure 2 represented to a greater extent uno vuo l, \. ::

  rclo pr-.rticllù of the. conprossion section '111:' \ t.rnlc do
 EMI23.9
 machine
 EMI23.10
 10./ pr601 to nontrant the operation d "<1sso :: 'blr - .. gc drn3 which the three constituents there a fncu are associated with a quatrifenu excavation do rcv6tonont - figure 3 is a vertical cut prticllu gr" ndio performed pn.rrilll-nbnt to the. direction of the paper will move, and showing the effective do edllngo bond obtained

 <Desc / Clms Page number 24>

 
 EMI24.1
 between all the crusts of the corrugations and the adjacent excavation of the new product - figure 4 is a partial perspective view of a fr'er'cnt of a creased board showing the possibility of crushing or creasing the new product so that it can be folded so as to constitute iar oxcaplu a rectangular box j - le. figure 5 is a cut - tE3vcret \ 1 p:

  \ rt1cllo back wheels do ra ^ .. 3.â1..4! and
 EMI24.2
 - figures 6, 7 and 8 represent graphic backs
 EMI24.3
 established dtiprbs a-ca r4su1tCLta d 'eaa': \ 1a included d "na table I, ei-onncx6, ot in which the velours of resistnoo perforation ot to 1 compression of flrxibayo are ruopeeti- vonant rc'pr <5acntcs a function of the total weight of the pinnoho of the total weight of the excavations do xovtoracnt ot do 1 total thickness of the hardwoods of r: .. vOtcnon -!;.



  In oc now deferring you mode of execution roproson- t4 by the fieuru 1t we see that the wavy interlayer designated by the reference 1, where first fornd in the zone of contact or mesh that foraent between them two cylinders of Cannes 2 ot 3, after having pre; ù, r..blo1unt conditioned the intcr'iairj with the help of humidity for exunplo, treating it with the
 EMI24.4
 water vapor, the two fluted cylinders being heated by a
 EMI24.5
 adequately, k..ndio that on 1 .. cylinder ', the intwra: 1 ^ .ira 1 receives glue lines 4 applied h. each creto do
 EMI24.6
 each corrugation using an adhesive roller 5
 EMI24.7
 Ordinary ltnx..idon or silicate glue can be used, provided it is designed so that it sets or lends itself to dislocation.



  In the case of aodiut1 silicate, a noxra-3.o solution at 38OB6 r'oDo6d:. '. Nt a ratio of the content n cilico (Si02) to. content

 <Desc / Clms Page number 25>

 
 EMI25.1
 on sodium oxidation (Nr% 20) included ontro 3 * 2 ot bzz Can & tM used diroctumonte In the case of ltOt1idon, an extension oontcnnnt 2qu do aatièroa uo3..ûvs ot comprising 15 kg of base ccustiquo in a 6ch "'Jltillan do 250 liters will give a satisfactory result * Do more, lo typo do colla based on 111t ... catie, prÓo6dotJr. have described, containing starch protein and other ingredients, an outside of 1J.u, can 6galoccnt ttro ouploy6t In all or.r, do the water qLetntît6 eufti8r.nto have oI: 1: .Jleyéo to obtain uno fluid consistency (with uno y18cOIJj, - t6 do 50 h 120 socondos / Saybolt, by oxoopio, for uno colla based on siliccto).

   Lo ra ^ .. tCrir.u corrugated oxt used for btro one of these types used in the manufacture of known types of corrugated cardboard, the tl .. 'l.tr1nu which this contends as the best is an interlayer. , pose do ie; / r: .2 to 176 g / m 2 as indicated above.



  After woir 6G convsmab3.oraan heated, the excavation do rovôtoaont 6 is nf, "Icn60 on a heated cylinder 7 which prosao the leafy do rovôtonont 6 against los sonsiots of the undulations of the intorcalniro ondulu '1, the heat making suttis {', Ct1on1i take the glue to join together the two components 6lSrantr one with the nutrc.



  This coated sheet can be formed by oxan- plo by very dense pure Kraft paper, and tortot1cnt created.



  He can ask 440 bzz, but because of his. density, it is not very p1s. It is directly in contact with the cylinder chuff <3 7, the corrugated interlayer 1 this 4vidow nt denourb chmd as a result of the corrugation operation and, therefore, the glue can easily fade last in this phase
 EMI25.2
 do the manufacturing.
 EMI25.3
 Far elsewhere, 1 leaf do roveteuent 6 for its composition.

 <Desc / Clms Page number 26>

 
 EMI26.1
 of relatively light paper when intended for construction.
 EMI26.2
 kill the intorf parts; 1di: U.rea of the final product. Donations 00 oae, bin that being in a pure Kraft paper even more donso, fortomont calender, the do revotérez sheet can pose only 205 g / m2.



  The whole nr9 of the leaf of the rovotoncnt the desired kind "r: only a thickness of about 0.58 f; U! 1 to L?, '15 that drJls the cc.3 of an impious do 440 gza and only one ipaiestur do Ot33 year at 0.41 ma nno lu ons of a paper do 2 (5u.



  On figure 2, three layers of the r.mt.5rinu rope-estd one being manufactured in figure 1 are reunited with a fourth deciduous do rovBtoacnt, which this p. ^ Odo one backs under undulations which would be exposed, Avrjat detro thus ^ ssorb3.c: s, lo commet do each ripple oxposôo
 EMI26.3
 receives an application of a second glue 9 again under
 EMI26.4
 iorzxo of a line flowing lo along; In this case, the glue is uno conposition so figoant to more kisso -corip6riturc.



  As shown in figure 2, all the undulations have; ¯ # tt 'oxi5cutvv; s during the operations represented by figure II, with on top soft layers of rolativornt undulations
 EMI26.5
 high or deep, while the lowest layer
 EMI26.6
 of undulations ^ been r81iaJe shallower or less high, the sheet of do revot will 6 and the sheet of revotea with the constituent J16cnt above are made of a heavier paper, put denac, while the other two excavations are carried out on : at; .ri ^ u do rcvfitonent lighter. If desired, glue 9 applied to the exposed corrugations of the top layer, may see a coq) osit1on giving the lowest of all tLrpGr: aur4s do figengo.



  Based on the operation of figure 2, all the excavations

 <Desc / Clms Page number 27>

 The piano liners or boils are minimized flat, straight and free from curvature, as far as possible. The layers are all compressed together, because the. The coating sheet 10 rests on a heating plate 8, while a belt 11 carrying the top coating sheet 12 presses all the layers together against the hot plate 8. Continuous production is possible by moving different layers. maintained under the conditions indicated, but in such a case,

   care must be taken to ensure that the layers do not effect any relative overlap with each other.



   It is believed that it is preferable to heat plate 8 at temperatures varying from about 149 ° C to a higher temperature of about 17 ° C or more. The time of exposure to this heat of the layers joined together may vary from a minimum, where there is a risk of destruction of the integrity or solidity of the layer, to a maximum such as it may be desirable for high speed manufacture - that is, just enough to set the glue 9 enough to hold the product securely together. Naturally, any moisture from the. glue or other causes must be eliminated to a fairly high degree.



   As already explained, the density of the cover sheet 10 facilitates the conduction of heat through this layer. The small size of the corrugations of the first element allows this heat to reach the coating or the coating rapidly. flat sheet to which the first series of undulations had been previously attached. The only obstacles which then oppose the heat transfer are the following two superimposed flat coverings, substantially thinner, as well as the air gap created by the corrugated interlayer placed between them.

   The radiation, plus the bath

 <Desc / Clms Page number 28>

 
 EMI28.1
 thorniquo provided by the rising vapor of un, sends heat to places where the freezing of In. collo is most difficult to achieve, namely the lines of glued 9 placed at the base of the undulations of the highest coucho. - ees of an intorcalairo ondula and a heavier excavation do rovôtomont, previously assembled.



  Lay co work offcctuG at a temperature n6cousaï- romont elovéo, the li, our do collo 4 previously applied no are damaged because ollos so component do ln collo which freezes at a tO: 1per: -. Ture higher and which rooto by cond6qLOrrt relatively insensitive to tcnpdruturos used8 ru course of this phase o.saot1blgo gen ': rr'.1. Specific compositions of glue which can be used are the following: - 'For in pronibro operation one can use 30 no silicoato when it is desired to use uno colla or s.7.iccto, When one wishes to use uno colla or s.7.iccto. Desire onployor uno collo à lirmidon, one can use a glue containing 15 kg of caustic base in a bath of 250 liters, co which gives a content of caustic base of about 2.7.



   - For the basic operation, approximately 12% clay is added to the silicate, and a silicate collo is desired.
 EMI28.2
 



  The caustic base content ranges up to 18 kg in a 250 liter bath, which gives a caustic base content of about 5.3%, when it is desired to use an adhesive. .1idoYl .. For the glue applied last on the uppermost layer, a composition containing
 EMI28.3
 70 do silicate, 6. Starch, 18 clay ot 6? * do borax when uno colla or silicate is required.

   When it is desired to use a starch glue, the given conposition
 EMI28.4
 for li socondo operation can btro modified -do way to

 <Desc / Clms Page number 29>

 contain approximately 20% of a polyvinyl acetate zmulsion, All percentages shown are weight percentages of dry glue *
In all cases, the glue 9 must forget a solid auffiacuruacnt set to allow handling. relatively thick product.

     As to the thickness, the two layers at the periouros of corrugated interlayer may be of the type called A defined by a depth of corrugation of around 5 mm with about 120 corrugations per running metro while the corrugated interlayer the more generally with reference to figure 2, can be made with corrugations of type called 0 having a depth or height of approximately 4 mm with approximately 139 corrugations per running meter.

   The finished plot product may have a thickness of about 14 mm, in Figure 3 is shown the general outline of the achoveo bond of glue 9 which includes the constriction or shrinkage generally desired but not always obtained near the top of the corrugation. , which suitable for all cases, and which contour also has side edges which are concave because they force lo meniscus do liquid glue before freezing.

   This type of bond is recognized as being particularly desirable and can be achieved in the case of thin corrugated paper products. Usually, it cannot be achieved along the entire length of the bond line, in the case of thin corrugated paper products. 'a triple-walled product such as that which has been described.

   overheating makes the glue brittle, so that the collo cracks or breaks when handling the board, resulting in the separation of the previously assembled layers. The relative slippage between the layers before the glue has properly set, results in the corrugation ridges spreading the

 <Desc / Clms Page number 30>

 
 EMI30.1
 glue would follow a large strip along the width of the plank, leaving a quantity of 00110 to remain, at one ... correct right ontru 10 sound of the corrugation and the rovbtezxmt which is insufficient! to produce an ooJ1venC \ blo bond between the constituent ú16ontu. This dtalomont has 68alonout the consequence of having to change the p1r.richo to its additive form:. '1.tO.

   The present invention pcmot to ensure the link between
 EMI30.2
 more satisfactory given the totality of the product.
 EMI30.3
 when all the. collo is not flsdo corrodtonont, it arises the problem of 1'caboutiseago or prefonnago folded back
 EMI30.4
 do this product very thick, adorns break or crack the uno
 EMI30.5
 any co-layers that would destroy the resistance in los plia ndcossr.iros for lr. foita-tion of plivos parts at right angles. In the case of lr. praonto invention, ootto operation can atro Ql: octu4c icoédi ('. toDont aprèn colle roprdsontuo on figure 2, do prfronco before the plrjnchc compoeda it 6té cut and laying h. that it subsisted oncora uno certain huaiditu in lo o: u 'ton / f1brû.

   It is not necessary to hunt the whole of the huuidt6 cotto
 EMI30.6
 considering the operation of figure 2, we reason
 EMI30.7
 doa new djorite characteristics, tup: 7xtvrnte This operation of orç80 or do L4rqua do pli have roprusento on in figure 4. the undulations of the plancha 13 are 4vidormQnt Ócra6vs, nuno zono rqlativenont largo designated cn 4, and the different sheets of revôtoa are so bring the uno closer to each other.

   Cotte zone d must fitro much more largo than colla adopted ordin: '. IroL1ont for loua
 EMI30.8
 more taincas corrugated materials,
 EMI30.9
 The special folding anorec ligno which is
 EMI30.10
 most efficient d6ro coano ost collo that would be achieved
 EMI30.11
 by means of the game da aolottoa tracousos repru ', are played on the

 <Desc / Clms Page number 31>

 
 EMI31.1
 Figure 5, lia nolottu u! '1o 14 presents all around its periph6rio a projecting or convex part 13 at the place where the board must be ot1boutio or n.rquee.

   The dinonsion, which the width of the protruding part is about 19 mm, while the coto b, which the height of this protruding part,
 EMI31.2
 is about 5no Lo profile of the tracer golot fonollo 16 corresponds exactly, in hollow, to the profile of the bare pebble and pr; '; sound, 4, op all around its periphery, a 6vîdemer-t or a gorgo 17 whose dimensions correspond to collof do la. protruding part of the maie pebble
 EMI31.3
 In function, lao galat nele is unonc6 in the plank porpendieulairemont 4 the direction of the undulations * The undulations are 6ezndon following uno bJ1Q âtandnnt lo long do lr. plant. The rcvbtomant marries exaoteuont lo profile do lt% protruding part of the roller do tI.'1rqUQgIJ n ".1o.

   Lo rov & to. mont infûricur is not entirely ropousad in the gorgo t: '. nnul: 1iro of the marking roller fcnjllo, z cause do l'cr.sew mont dos undulations, However, in the pr6: tomro.g.> finished the rcvOtct1ont in contact with the fonollo tkrqunge roller below the plane of the surface of the board *
 EMI31.4
 This type of oaboutisaago has the advantage of soliciting the plancha in the direction in which this part should be finally solicited when uno kicks this f.briqudo from the plank.

   L'cnorco do folding described above this uno: "'J'.1OrOe do folding a flap, co who will say that olo foto a line of folds .: in ly1? Lnncho that separates the flaps used to fornor the top and the bottom of a box from the sides of the goose glue
When a box is made with lo cardboard which has just been described, the flaps are folded inwards, towards the back of the boot.

   Under these conditions, lo

 <Desc / Clms Page number 32>

 
 EMI32.1
 Yovotonont which had prooodecnont been in contact with the galot of the male prjforDDGo is protond6nont sinking while the rovoton which had previously been in contact with the galot of prefomago fenolla this fortont stretched I, tt'J3C) rce of folding described above tends to solicit los rcvtoDont8 oxactenent in such a way that the folding is carried out easily ot that the rovôtoncnta does not undergo any deterioration during this operation do pli ^ .go, The narquago or prdfornago do plis does not need to be followed by the floxion or the product pliago. The product, cut in lengths -td6quatco, is enpilo do pz, 4fjrjnoo and it is left to stand for a ddtornind time, which fltro ppo16 period of utblis8Q.

   Should this period all residual moisture evaporate ot los 61, the constituent parts of the cardboard acquire a tonour on huuiditú which oat stb111 .. born by report to 1 * oiled wo the surrounding atmosphere * In some water, a duroiso will cost: 1plQl3ontniro do 1 ::
 EMI32.2
 glue so produced during clear period. By co above, we get a new product, soue
 EMI32.3
 volume of three layers of corrugated intorocline, soft of which present deep undulations, and one of which, at the end of the contralto layer, presents non-round undulations.

   These three constitutive clunonta are interposed between çuaïro layers or fouîllos pianos, the soft located on the outside of which are oonotitudos by pure Krft paper, rcintivooont louri, but very dinea, tension that the soft inner sheets are rúis6oB in pure Kraft paper. egalo density Liris albeit or more ninco.
 EMI32.4
 



  Collaborative liaison is, in all cases, typo
 EMI32.5
 represented in the figure- 3. the use of the soft typos of glue ost made evident by chain link and by its caraotciristi-

 <Desc / Clms Page number 33>

 ces, otherwise the lowest bonding tips would not have the desired characteristics .. They would fail to be brittle, distorted and weak.



   ] In addition, by crushing the lines of leader or folding mark as shown in figure 4. so that the lower layer constitutes the exterior of all the partita folded at right angles, the breaking of the coatings and especially that of the coating lower or outer layer is prevented during this folding, The bottom or outer layer of corrugated interlayer. Relatively shallow conduits also help to prevent breakage of the outer coating since there is paper in the shallow corrugations which bear against this outer coating.

   Likewise external crushing. such as that which can be caused by placing concentrated loads on the surface of the board is largely eliminated, as shallower corrugations provide greater rigidity in the direction of such pressure.

   Referring now to the diagrams in Figures 5 to 7, based on the data entered in Table I below, the following observations can be made 1
The diagram in figure 6 shows the properties of resistance to perforation and to compression of the board, represented as a function of its total weight, the curves connecting the test points S1, S2, S4, respectively representing the samples 1, 2 and 4 which have the light corrugated interlayer with intermediate cover sheets of varying thicknesses. Thus, the variable for the curves in question is the weight of the smooth coating sheets.

   These curves demonstrate and establish the concept of the prior art that increases in the weight of the coating sheets increase the

 <Desc / Clms Page number 34>

 
 EMI34.1
 onrnot6rietiquQs do 81stanoo to the perforation and to the conproasion of the board Ion pointa S ot si3 de oc dia- granno represent the planks wall triplo and with interlayers heavy corrugations, ot they will have lincerotesor arqua dos cctúri8iquoa of resistance to perforation ot to the oonproasion. The curves relating to the tripla-walled cardboard with heavy corrugated spacers have not been shown, since the data correspond to the sample NI '3.



  We will see it if we have cop16nentair test results * for triple pnro1 cardboard with heavy interlayers, curved backs could be traced by the pointa 53 'which would be situúos u-doosus curved backs obtained for I # interlay-% ire lugor <The relative curves of tripla-walled cardboard with heavy corrugated interlayers would probably extend to the left of the diur: ". 1'1iJv, towards a common origin with los king curves related to: 1.ntJrotÙ:

  ú.roe ldaore, Thus, the ponto of the curves for the 1ntorc .... iros lourda would be greater than the glue of the curves for the intoroalairas 16gors, The increase in the panto, which
 EMI34.2
 represents the ratio of the properties to the total weight of the
 EMI34.3
 board, constituted uno riosuro of the efficiency of the board
 EMI34.4
 ot, therefore, it is seen that a walled carton triples to
 EMI34.5
 Heavy 1nteTCiros has a more rrrndo display: oit4 as well as aoillouros absolute values on co concerning the properties of rs1stAcù to the perforation and to the conprossion. the d1ee of figures 7 ot 8 countering curved backs for interchangeable backs ^ .1 ^ .irr3 light wavy shown rospocti-. depending on the total weight of the mat sheets and the total thickness of the excavation excavations.



  Confused with the oormontaries relating to the curves of figure 6, the diagranes of figures 7 and 8 show equal

 <Desc / Clms Page number 35>

 
 EMI35.1
 the concept of the. technique ^ .nt: r3.ouro according to whoever the properties <5s of the board depend on the weight of the excavations do will revotate and do the thickness of the excavations do rovatot \ #t.



  Conno in lo c-a-do figure 6, the points 33t S13 ropi'6senting the triple-walled cardboard to intera ^ a. ^ 3, roa heavy ondulas put on Jvidonce 1161ioration mrxqueu obtained p:, x cetto
 EMI35.2
 disposition
 EMI35.3
 We oot1.10 that the di: -. Gr: '. It \ os show why the practice of .r later technique consisted of t11ro varior lo weight and up ^ iasour dos only rovbtotionte # rtii to obtain a: ugwont tion of the properties of rsietancc perforation and lr. eonprossion, but not to vary 10 weights and the Óps8our wavy spacers.



  Lot ronaeignea are available so linitont court of table 1 and, therefore, it is actualfllcnont.: I.t1possiblo
 EMI35.4
 other
 EMI35.5
 to provide nuouno / ghiquo rcprsontation of the properties of the
 EMI35.6
 triple-walled cardboard with heavy dividers compared to
 EMI35.7
 those of the triplo wall cardboard with dividers 1 (, er8.
 EMI35.8
 Of course, the present invention is in no way
 EMI35.9
 linit (2e to the embodiments and embodiments described and roproacntos which have been given only by title of xer \ p10 and many variants can be made to it meaning however to go beyond the scope of liinv # nt3on.

 <Desc / Clms Page number 36>

 



    TABLE 1
 EMI36.1
 Properties and test results of specific triple-walled corrugated csrtons (c.zl:> cubJ.a!:. "E of C-A-A type corrugations)
 EMI36.2
 T #### '' CoQDOsitionof the board {Characteristics of! 'Features of insistence Insistence Features! 1 chan- i * "" *! 1 t panel: 1ble of the browsing all the intemà la perm-! A la corner- global of the! Furrow; of cardboard! the coating! wavy cnlaircs¯¯¯'on'jssj2.-2E '! D1S? OsJ.tion des; Weight! .....! ! i! -, '.... 1.



  ! re, areolar leaves; skirts iloids weight. 1; ,, "111; mIt.l. areolai-Lu;, I; pais-! Vêtet1Cû't d.:SJ.- ides wteIli arcolalrc! - ± -Jpaisseui ar.Jolave! Dc; a.réoa5m seur.t . Identified by their Scalars; b / m2 1 can g / vm tear. g / m, ram;? oi & s areolarjen¯g / m2¯¯; j ¯¯¯ ### ##### .. j 1! " ! pf i2Sbsf¯ "i27! 618.87; 2.134 ji 0.762; 52.74 (32 2947 j2202.76 j2.6S6 '2; 439-205-205-439! 127! 1338.64! 1.930 538.89 1 or 762 30.62! 2706 1922.53! 2.6S ±! 3 i439-205-205-439i 161 i 1338.64 1.930 742.06 i 0.914. 33.71, 3072 2000.71 i2.845 1 4! 43S-312- 205-439 '127 1 1478.76' 2.052! 538.89 0.762 31.53 2732 2062.65; 2.794
 EMI36.3
 e weights and thicknesses of individual sheathing sheets and interleaves used in the boards
 EMI36.4
 above:
 EMI36.5
 ! quality (weight Actual area weight;

   Thickness ; ,, .. ro, Z.ir, e noni-! g / r: .2! nal cn PLm2) 1 ############ - t 43S, 38 456.47 0.610 312.45! 352.57 0.457 205, O4! 212.86 0.356! 161 [Ï? i 6'l, A5 0.305 1,126; 93 01.81 0.254
 EMI36.6
 of type A and of 1.43 for undulations of type 0 Iôr;: v: eur "". . one side


    

Claims (1)

CLAIMS 1, - A method of manufacturing conulated wall cardboard. multiples of the type consisting in associating at least = or preferably three webs formed of sheet, interlayer coating interposed between at least three or four flat covering sheets respectively spaced by said corrugated spacers and bonded by gluing thereto, said method being characterized in that it consists, parai other operations known per se, in stretching the aforementioned covering sheets from one end to the other and stretching them in order to positively maintain their flatness throughout the manufacturing process, in assembling the constituent layers in their frankly formed and slightly damp state, with all the glue incompletely set by pressing them simultaneously, continuously and firmly together while said covering sheets are kept taut and any relative sliding of the component elements against each other . to the others is prevented, the humidity, but all of it being progressively removed in a substantially uniformly composed manner by heating, to cool the floor thus obtained while it is still under tension, and, immediately thereafter, to crease or optionally folding said board according to the requirements of the subsequent folding while there still remains a certain humidity therein, and, finally, optionally stacking the finished product cut to the desired dimensions $ for a period of establishment in order to allow the humidity residual to evaporate and the constituent elements of said board finally acquire a stabilized moisture content relative to the humidity of the atmosphere approximately. nanto <Desc / Clms Page number 38> 2, - Process according to claim 1, characterized in that the outer covering sheets preferably having as known per se a higher weight than the inner covering sheets, the aforesaid covering sheets of very high density obtained by l use of heavily calendered paper; 3, - Method according to one of the preceding claims, characterized in that, for the manufacture of the single-sided separate couchos, the ridges of the corrugations of the aforementioned corrugated spacers are glued together, which are to be glued to the smooth coating excavations using a glue composed so as to set at relatively distant temperatures 4.- Method according to one of the preceding claims, characterized in that when the various aforementioned layers on one side are juxtaposed with an excavation of additional exterior coating to form the final product, at least one type of coating is used. glue which is composed so as to set at relatively lower temperatures; 5.- Method according to one of the preceding claims, characterized in that one uses in one product name the aforementioned corrugated spacers of various heights of corrugations, for example, as in the case of a triple-walled board. comprising two spacers with relatively high corrugations and a third interlayer with shallower corrugations, the elements are assembled in such a way that the said shallower corrugations are found as close as possible to the source of heat used to harden the glue necessary for link the different layers together; 6, - Method according to one of the preceding claims <Desc / Clms Page number 39> characteristic in that during the aforementioned assembly phase, an adhesive is applied to the tops of the corrugations closest to the aforementioned heat source, an adhesive composed so as to set at temperatures somewhat higher than those relating to the adhesive used for fixing the ripples furthest from said heat source; 7.- A method leveling one of the preceding claims, characterized in the case of the assembly of all the insane elements to form the aforementioned board with multiple walls, a type of glue is used which can be heated at high temperatures. , before it is applied to the tops of the corrugations of the aforementioned corrugated spacers, a tiller sticks together by oxomplo on a large part of sodium silicate, starch, clay, water and other ingredients 8, - Method according to one of claims? above characterized in co that one uses for the aforementioned collo hardening at relatively high temperatures, that is to say a solution of sodium silicate with 38 Bé of density, having a ratio of the content of silica to sodium oxide glue of between 3.2 and 3.33, i.e. a mixture based on starch containing 20% solids and comprising 15 kg of caustic base in a bath of 250 liters, which results in a caustic base content of about 2.7%; 9.- Proceeded according to one of the preceding claims, cacasterized or co-used for the aforementioned glue setting at a lower temperature, either the aforementioned mixture of the silicate type to which approximately 12% clay is added, or a starch-based mixture containing 18 kg of caustic base in a 250-liter bath, resulting in a caustic-base content of about 3.3%, and one used for the highest such layer, applied last, i.e. a composition <Desc / Clms Page number 40> silicate typeface containing approximately 70% silicate 6% starch, 18% clay and 6% borax, by weight of dry product, or the aforementioned composition of the starch typeface modified to contain approximately 20% of a polyvinyl acetate emulsion; 10, - Process according to one of the preceding claims, characterized in that the aforementioned folding initiators are carried out in order to form in the. board composed by crushing corrugations in the transverse direction thereto, a substantially straight folding strip, the arched cross-sectional profile which is concave on the upper layer and convex to the lower layer, the outer layer of aforementioned corrugated interlayer with relatively deep corrugations when provided, preferably forming the lowest or bottom layer of said board; 11.- Method according to one of the preceding claims, characterized in that the aforementioned folding amoreos are carried out in the aforementioned corrugated cardboard board by pressing from above a male marking tool or punch which stamps said substantially horizontal board. perpendicular to the axis of the corrugations so that the smooth top or top covering sheet exactly matches the profile of said male marking tool, while the bottom or bottom surface excavation is on a female marking tool forming a matrix which rests against said sheet so that it is not completely twisted into said female tool, but still sufficient to descend below the lower surface of the said plank. <Desc / Clms Page number 41> 12.- A folding preforming device, done at the mine by carrying out certain operations of the aforementioned method on a corrugated cardboard board 4 multiple words of the aforementioned gonro of the type comprising at the monk a pair of rotating profiling rollers one look constituting the one a male tool forming a punch or the like having in cross section and a protruding forming part, and the other a forming tool forming a die or the like having; a transverse diction evidomont corresponded in crcux, said device being characterized in that said male roller is superimposed on said female galot so as to carry from above on the upper face of said board said projecting part of said mole galot forming a projection with an arcuate profile around its periphery with a width of about 19 mm and a height of about (mm, while said recess around the periphery of said female roller which; term a substantially exact footprint of said protruding portion of said male roller has dimensions corresponding to those thereof. 13.- As a new industrial product, a corrugated cardboard board with multiple walls, manufactured by applying the aforementioned method and devices of the type comprising several layers of aforementioned corrugated interlayers alternating with the aforementioned smooth pits of coating and whose weight is higher in the two outer layers than that in the inner layers which are thinner, said cardboard being characterized in that the above mentioned sheets are all of the same very high density and preferably made of pure, highly calendered Kraft paper or the like. , and they are assembled with the undulations of a <Desc / Clms Page number 42> EMI42.1 side of the corrugated spacers must be used with at least one type of glue, and, with those on the other side, using at least one other type of glue, said glue being finned in the parts to unite ot being form ot free of and- EMI42.2 fats do surcht '. \ ltf'D8o in the whole of said product; 14.- Corrugated board according to claim 13, characterized in that the aforementioned corrugated spacers have a relatively very high weight ot are assembled to EMI42.3 sheets do rov6teDent preoitéos of which at least some have evontuollocont a relatively reduced weight and thickness} f 5, - Corrugated cardboard board according to one of the claims 13 or 14, characterized in that in the aforementioned board corrugated cardboard triple wall, which is of the type EMI42.4 comprising by soft oxomplo excavations outside of the above mentioned coating posing approximately 440ke / m2 and having a thickness of approximately 0.56l: 1li. at about 0.76zm, and two intermediate smooth sheets weighing about 205g / m2 and having a thickness EMI42.5 from about 0.33 years to 0.4f, the weight and back thickness of the aforementioned corrugated interleaves vary from 146g / m2 and 0.28mm respectively to those of the heaviest and most loving interlayer than the 'we can practically wave, and are EMI42.6 preferably, from 61 g / m to 176g / m2 and 0.30mcf respectively 16.- Corrugated cardboard board according to one of claims 13 to 15, characterized in that dr-no the aforementioned triple-walled corrugated cardboard board which is of the type comprising EMI42.7 soft corrugated interlayers have deep corrugations, for example of type A having a corrugation depth of about 5mm with approximately 120 corrugations per meter running and a third corrugated interlayer on the outside of the central interlayer made with back ripples less <Desc / Clms Page number 43> deep such as type C which has a ripple depth of about 4 mm with about 139 ripples per running metro, said corrugations are linked on one of their sides to the above-mentioned adjacent coating excavations. using a glue setting at relatively high temperature and on the other side using a wedge, another type of collo setting at relatively lower temperature. 17.- Process in substance comas described and: shown in the accompanying drawings. 18, - Device substantially as described and shown * in the accompanying drawings. 19.- Board on corrugated cardboard or retort substance described and shown in the accompanying drawings,