MXPA96004674A - Manufacture of multiple layer paper laminates using penetration of adhesive control - Google Patents

Abstract

This invention relates to the manufacture of laminates of adhesively bonded web paper of three or more layers. The preferred sheets are manufactured by flexographic printing using a novel technique of controlled adhesive penetration. The multilayer laminates of this invention are especially suitable for paper products such as disposable table napkins, since they can be printed on the edge without embossing embossing or loss of coincidence.

Description

• • • • • "MANUFACTURE OF MULTIPLE LAYER PAPER LAMINATES USING CONTROLLED ADHESIVE PENETRATION" BACKGROUND OF THE INVENTION 5 FIELD OF THE INVENTION Our invention relates to the manufacture of adhesively bonded web laminates of three or more layers, manufactured using a technique of controlled adhesive penetration, wherein multiple joints between the layers are achieved using a single adhesive application. The multi-layer laminates of our invention are especially suitable for color printed paper products, such as disposable table napkins, since our laminates can be printed in color to their edges without the loss of coincidence that usually accompanies embossing in embossed edges.

DESCRIPTION OF THE PREVIOUS TECHNIQUE The conversion processes to manufacture these products as three-layered paper napkins typically depend on the embossing of embossed edges for retain the layers together. In the older flexographic printing presses designed to convert the paper roll into napkins, the cutting and embossing edges steps typically precede the color printing operation. As a result, it is difficult or impossible to print colors up to the edges of finished napkins because an adequate match of colors can not be achieved at embossed edges. Therefore, printing on most paper napkins a Colors are restricted to the center not embossed in the napkin. Some newer flexographic presses designed to convert laminated three-ply paper into paper napkins that perform embossing operation on edge after color printing. But these machines are also subject to problems of coincidence when they use non-adhered, loose three-ply paper. In addition, since the individual layers in multi-layer paper napkins manufactured in both older and newer equipment are typically fixed to each other only in embossed areas in relief (usually limited to the edges), the shapes of the novel napkin can not be cut because the layers separate from each other. As a result, for practical purposes, paper napkins are almost always limited to square shapes. Attempts by the prior art to deal with these problems have used adhesive to join the layers together, thereby reducing or eliminating the need for edge embossing. But these prior art processes have required multiple adhesive applicator stations, typically one of these stations for each bond or bond between the layers. In this way, for example, a three-layer laminate required two applications of adhesive. Also, when the adhesive was applied between the layers by spraying, an amount of adhesive was used much more than is necessary to glue the layers together. Therefore, the prior art approaches to the problem of achieving adhesion of the layers throughout the entire laminate surface required an additional set of adhesive application rolls for each additional layer. This contributed to the cost complexity of the processes of the prior art.

BRIEF COMPENDIUM OF THE INVENTION It has been found that multilayer laminates can be manufactured using a novel process that depends on the controlled penetration of the adhesive from one surface of one carrier sheet to the other. This allows one or more additional layers to adhere to the side of the carrier sheet opposite to that to which the adhesive was applied. By controlling the basic weight and air flow porosity of the carrier sheet and the additional layers, as well as the adhesive properties and the solidification time, three or more layers can be joined with only one application of adhesive. It is unnecessary to apply heat to ensure proper penetration of the adhesive. And the napkins manufactured from our laminate can be printed to their edges without loss of color match and with approximately 25 percent or less of waste and what is usually experienced to convert the non-adhered three-ply laminate into paper napkins to Through embossing in embossed edge. In a preferred embodiment of our invention, a flexographic printing process is used to apply the adhesive to the carrier sheet. In the manufacture of a three-layer laminate using layers having a basis weight of approximately 4.40 kilograms per 836 square meters, we have achieved very acceptable release resistances between all three layers at polyvinyl alcohol adhesive coverage levels of only 1 percent to 2 percent of the surface of the paper. Only one adhesive application was used to adhere the three layers together. Other embodiments of our invention include a variety of processes using alternative adhesive application techniques while still achieving a controlled penetration of adhesive. Even though the manufacture of paper napkin feedstock is an important application of our invention, there are other uses as well. These include applications such as manufacturing three-layer table covers where one layer can be a plastic sheet impervious to liquid; reinforced laminates wherein the carrier sheet is selected from one of a number of resistant synthetic materials; paper / metal laminates eg chewing gum wrappers; and padded laminates including one or more layers of very high volume. An object of this invention is therefore to provide multi-layer paper laminates by applying only one layer of adhesive to achieve two or more joints between the sheets. Another object of this invention is to provide these multilayer laminates where comparable release resistances are achieved between the layers.

Another object of invention is to reduce to a minimum the amount of adhesive used to achieve the bond between the multiple layers of the laminate. A further object of this invention is to provide a flexographic process for manufacturing these laminates, as well as other process alternatives.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a drawing of a three-layer laminate made using the process of this invention, showing the two outer layers peeling back from the central carrier sheet. Figure 2 is a schematic view showing an installation of a flexographic printing that has been specially modified to produce a three-layer laminate using invention. Figure 3 shows a flexographic plate roller equipped with a rubber mat of a design that we have found appropriate to carry out invention. Figure 4 is a schematic view showing an alternative special flexographic printer installation that can be used to produce a laminate of five layers using invention.

Figure 5 is a schematic view of a rotogravure type press modified especially for the practice of invention. Figure 6 is a schematic view of a press in which a special pressurized roller is used to practice invention. Figure 7 shows a possible pressurized adhesive feed arrangement for the roller of Figure 6. Figure 8 is a schematic view of an alternative process for carrying out invention using spray lines of adhesive. Figure 9 shows an adhesive sprayer for applying parallel lines of adhesive. Figure 10 is a schematic view of another alternative process for carrying out invention using a hot-melt adhesive. Figure 11 illustrates a laminate made using controlled penetration where the characteristics of the layers are selected to allow various patterns of adhesive to be created on one side of the carrier sheet. Figure 12 shows a padded laminate manufactured using a high-flux carrier sheet.

Figure 13 shows a rubber mat pattern suitable for producing the padded laminate of Figure 12.

DETAILED DESCRIPTION OF THE DRAWINGS Referring initially to Figure 1, the structure of a three layer laminate made in accordance with this invention comprises a carrier sheet 1, a second layer 2 and a third layer 3. The second and third layers are shown peeling off the carrier sheet . Between the layers and the carrier sheet, there are the pattern 6 of adhesive applied initially and the pattern 7 of adhesive that has fully penetrated. Figure 2 illustrates a preferred embodiment of invention, using a flexographic press to apply the adhesive. The carrier sheet 1 and the third layer 3 are wound together in the unwinder 9. They are unwound from the unwinder 9, around the tension roller 18 and from there to the holding point 16 between the plate roller 11 and the printing roller 4 . The adhesive 6 is applied to a surface of the sheet 1 carrying the textured rubber mat 15 on the outside of the plate roller 11. At the clamping point 16, controlled penetration of the initial adhesive pattern 6 begins.

The carrier sheet 1 and the third layer 3 furthermore go around the printing roller 4 to the lower calender roller 5. At that point, the first layer 3 (which is unwound from the unwinder 13 and fed past the tension roller 19) is pressed against the adhesive pattern 6 at the attachment point 17. The high pressure exerted between the calender roller 7 bottom and the printing roller 11 complete the operation of forcing the adhesive through the carrier sheet 1 to form a pattern 7 of fully penetrated adhesive. From the clamping point 17, the finished three-layer laminate advances towards the re-furling 14, in which the finished roll is wound. In this preferred embodiment of our invention, the adhesive is applied to the anilox roller 10 by means of an inverted double-angle scraper blade system 12. The anilox roll 10 transfers the adhesive to the pattern raised on the rubber mat 15 just as ink is applied in a regular flexographic printing operation. As an alternative, to the double reverse angle scraper blade system 12, the aniloxy roller 10 can rotate against an ink roller (ns illustrated), which in turn picks up the adhesive from a through feed (not shown either).

We have found that an appropriate pattern for the rubber mat 15 is that which uses 0.80 millimeter points in a diamond-shaped pattern at centers of 6.73 millimeters and 9.42 millimeters. See Figure 3. This pattern provides approximately an area coverage of one percent, which we have found is more than sufficient for a three-layer product. Another appropriate pattern uses points of 1.59 millimeters and provides an area coverage of 3.1 percent. In general, larger points provide increased adhesive penetration and are especially suitable for use with low air flow papers. The preferred blade speed for this mode is between 15.24 to 914.4 meters per hour, with the especially preferred scale being 161.54 to 762 meters per hour. At the lower speeds, the adhesive tends to solidify between the point of application of the adhesive to the rubber mat 15 and the transfer of the adhesive to the carrier sheet 1 at the attachment point 16, causing some accumulation in the fiber in the 15 rubber mat. The speed limit of the top sheet depends mainly on the capabilities of the equipment. The appropriate amount of "pressure" or interference, at the clamping point 16, where the adhesive is applied, is between .0508 millimeter to .0762 millimeter. High pressures must be used between the printing roller 4 and the lower calender roller 5 to facilitate penetration. We find that pressures of approximately 3.45 kilograms (pli) are appropriate. Pressures greater than .575 kilogram and less than 3.45 kilogram are especially preferred. Our invention requires the proper matching of the properties of the carrier sheet, the other layers and the characteristics of the adhesive. It is important that, with an appropriate selection of the type of adhesive and characteristics of the carrier sheet, heat need not be applied to facilitate the penetration of the adhesive. We will discuss those factors below. Figure 4 illustrates an embodiment of our invention in the manufacture of a five-layer laminate. This can be achieved by adding an additional unwinder 20 where a second carrier sheet 21 and a fifth layer 22 are wound. The adhesive is applied to the second carrier sheet 21 by a second plate roller 26 carrying another rubber mat 27, which in turn it is fed by means of a second anilox roll 25 and by a double reverse angle scraper blade 24. The three-layer laminate can be fed directly to the clamping point between the second printing roller 28 and the second lower calender roller 31, from an initial production operation of the kind shown in Figure 2. The five-layer finished product can then be Alternatively, of course, a laminate having five or more layers can be manufactured in two passes through the equipment shown schematically in Figure 2. In this case, the three-layer laminate manufactured in an initial step it is unrolled from the uncoiler 13, with two additional layers added to the uncoiler 9. The operation of our process is otherwise similar to that described above. It will be understood by those skilled in the art that laminates having even numbers of layers can also be created using the process of our invention, simply by using a step in which only one layer is added instead of two. All these variations are within the scope of our invention, which we leave limited only as stated in our claims. Referring now to Figure 5, we show another embodiment of our invention wherein the method of applying flexographic adhesive using an anilox roll and a rubber mat is replaced by an engraved roll 40 that rotates against a flat roll 41, an arrangement similar to a rotogravure press. The adhesive pattern 46 is applied to the carrier sheet 38 from the reservoir 39 through the pattern on the engraved roll 40. The carrier sheet 38 and the third layer 37 are fed from the unwinder 36. The first layer 44 is unwound from the unwinder 43 and is joined to the carrier at the point of attachment between the flat roller 41 and the flat roller 42. This creates a pattern 47 of adhesive between the carrier sheet 38 and the third sheet 3, as in the embodiment of Figure 2. Figure 6 illustrates yet another embodiment in which the adhesive is pumped from the tank 49 by the pump 50 to a plurality of holes 52 in the periphery of a perforated drum 48. The periphery of the drum 48 rotates against the printing roller 4. This creates a pattern 6 of adhesive. Figure 7 shows a detail of a possible feeding system for the perforated drum 48. In this embodiment, an adhesive feeding pipe 53 terminates in the plenum 54 at one end of the drum 48. The feeding holes 55 drilled in the periphery of the drum 48 parallel to the axis of the drum 48, is brought into contact with the chamber full 54 and remains motionless as the drum 48 rotates. The adhesive then moves through the feed holes 55 and outwardly from the perforations 52, - * >; V thus producing a desired spot or other adhesive pattern on the carrier sheet. Alternatively, of course, the entire drum interior 48 could be pressed with adhesive. 5 Figures 8 and 9 still illustrate another possible adhesive feeding arrangement. In this embodiment, the adhesive is pumped under pressure to the feed line 56, from which it is sprayed in a series of jets 58 from a plurality of holes 59 toward the sheet 1 carrier. The result is parallel lines of adhesive along the length of the roll of the laminate. This mode eliminates the need for any adhesive feed roll system. Figure 10 illustrates yet another modality of our invention, using a hot-melt adhesive. In this embodiment, a two layer roll comprising the carrier sheet 67, the third layer 68 and a pattern 66 of hot melt adhesive (which can be applied by a variety of techniques known in the art) is first wrapped in the unwinder 60. The two-layer roll with the two layers still not fixed to each other, is unwound from the unwinder 60 and between the heated roller 65 and the pressure roller 72 (which may also be heated, if desired). At the same time, the first layer 69 is fed from the unwinder 61 towards the clamping point between the heating roller 65 and the pressure roller 72. This melts the hot-melt adhesive pattern 66 sufficiently to cause it to penetrate through the carrier sheet 67 into the third layer 68, while also fixing the first layer 69. The resulting three-layer laminate is wound onto the furler 71. It will be evident to those skilled in the art that can be used to practice our invention a variety of other equipment arrangements. For example, other adhesive application trains are possible. We intend to include all these variations, limiting our patent only as stated in our claims. DESCRIPTION OF THE MULTIPLE LAYER LAMINATION THAT CAN BE PRODUCED USING OUR INVENTION The most sensitive three-layer laminate that can be produced using our invention is shown in Figure 1. In that structure, the pattern 6 of adhesive is applied to a surface of the sheet 1 carrier, and our process causes the pattern to penetrate through the carrier sheet creating the pattern 7 of adhesive on the opposite surface. The characteristics of the carrier sheet 1 are selected to facilitate the penetration of the adhesive; the characteristics of the first layer 2 and the third layer 3 are selected to minimize or prevent the adhesive from penetrating through those layers. It is also possible to manufacture laminates using controlled penetration of the adhesive to fix the multiple layers on one side of a porradora sheet. Figure 11 illustrates this arrangement. In this embodiment of our invention, the carrier sheet 1 is selected to have a very open structure (using the criteria indicated below); the first layer 2 is selected for a much less open structure as well as the fourth layer 73. The third layer 3 is selected to have an open structure similar to the carrier layer 1, thereby allowing the adhesive to penetrate through the third layer 3 as well as through the carrier layer 1. This creates a pattern 72 of adhesive between the third layer 3 and the fourth layer 73, while preventing the penetration of the adhesive beyond the first layer 2 or the fourth layer 73 By selecting intermediate levels of the open structure (as preferably measured by airflow tests) for the intervention plates, similar release resistances can be maintained for several of the adjacent layers while only one application operation is still employed. adhesive. Or, if desired, for a certain special object, one or more layers can be produced more easily to separate them from the rest of the structure by limiting the penetration of the adhesive through those layers. We call this the balance of the properties of the sheet between the penetration of the adhesive to ensure adequate adhesion between the layers while preventing the penetration of the adhesive towards the outer surfaces of the layers further outward "controlled penetration". In still other modalities of our invention, not all layers need to be made of paper. For example, one or more of the outer layers may be flexible metallized sheets such as in the wraps for chewing gum. Similarly, the carrier sheet may be of a spunbonded setic material having appropriate air flow characteristics. This carrier sheet adds strength to the laminate. The variable resistance layers can also be used to produce items such as "popcorn" bags in a microwave oven. In that case, the sheets and the adhesive are selected to provide strength while retaining the ability to release moisture during the operation. Another structure that can be produced using our invention is shown in Figure 12. In this embodiment, the rubber mat 15 is modeled with a diamond pattern of lines 78 raised as shown in Figure 13, a In order to place a pattern 75 of diamond-shaped or quilted adhesive, this pattern is applied to a high-fluff or creped carrier sheet 74 which is wound onto an unwinder together with a much tighter third layer 76. An First layer 77 much tighter in a separate unwinder The mode of the process illustrated in "Figure 2 can be applied causing the adhesive pattern 75 to penetrate into the large carrier sheet 74. sponge and can create a pattern 78 of corresponding diamond-shaped adhesive retaining the high-flux carrier sheet in the third layer 76. The result is a sealed sheet of paper having excellent insulation properties due to its large fluffiness, but with stronger and tighter outer layers. This laminate is ideal for disposable hospital gowns. Optionally, the outer layers can be made of water-resistant synthetic materials to create a laminate that also repels water. A use for that laminate is for disposable table covers. The following table shows a selection of paper types that are suitable for use in the different modalities of our invention. 25 TABLE 1 Type of paper Basic weight Silk Flow .454 Kg / Air 836 meters2 liters / second Acqueado en Seco 13.5 235.95 Accreted in Dry 11.0 129.77 Accreted in Dry 10.5 75.50 Acqueado en Seco 9.7 56.63 - 60.07 Accreted in Dry 14.0 9.44 - 14.16 Accreted in Wet 14.0 23.60 Glaze in Machine 12.5 < .47 Linked by Yarn 16.95 gr / mt2 283.14 Synthetic Linked by Yarn 33.91 gr / mt2 141.57 Synthetic TABLE 1 (continued) Type of paper% of MD Resis Silk Calibrate Lengthening to Load Tension of Zero kilogrammeters tros Accreted in Seco 80 0035 .356 Accreted in Seco 50 .0058 279 Accreted in Seco 22 0081 .152 Accreted in Seco 12 .0127 .076 Accreted in Seco 0310 102 Accreted in Wet 0575 .102 Machine Glaze 069 051 Linked by Synthetic Yarn 20 0258 178 Bonding by Synthetic Yarn 40 .0575 3.30 The types of natural paper are placed in order of descending open structure, as shown mainly by the air flow. We prefer to determine the air flow using an air flow tester manufactured by U.S. Testing Co. of Hoboken, N.J. The air flow is measured in liters per second (CFM) through 9,290 square centimeters of fabric at a pressure drop of 12.7 millimeters of water. To be used as a carrier sheet, we have found that an air flow of at least about 18.88 liters per second is required. The greater the air flow, the greater the amount of penetration of the adhesive at a given adhesive viscosity. Both synthetic spunbond bonds shown are suitable for use as carrier sheets. For intermediate layers such as those shown as reference number 3 in Figure 11, it may be desirable to use an intermediate air flow figure. Typically, air flows within the range of about 23.60 to about 47.20 liters per second, are of course preferred depending on the number of layers desired. For use as outer layers (those layers shown in Figure 11 in reference numbers 2 and 73, for example), a less open paper is desired. Preferably, layers having air flows of less than about 23.60 liters per second, and still more preferably less than about 9.44 liters per second, should be used. This helps to avoid the penetration of undesirable adhesive. None of the materials bound by synthetic yarns in the above table would be suitable as outer layers. Under some circumstances, the water content of the paper can become important. Water contents of about 3 percent are preferred since an excessive amount of fine powder can be created at less than that level. It can be seen from the above Table that the basic weight of the individual layers can be controlled through a fairly broad scale regardless of their suitability for use as carrier sheets or outer layers. DESCRIPTION OF APPROPRIATE ADHESIVES A wide scale of adhesives can be used in our invention as long as care is taken to match the viscosity and other properties of the adhesive, as applied, with the open structure of the selected carrier sheet. The following types of adhesives can be used: silicates (especially sodium silicate); tail or animal gum; glue or fish gum; tail or casein gum; cola or soybean gum; starch-based adhesives; borated dextrin such as 13-1200 and 13-1558 from National Starch and Chemical Company; polyvinyl alcohols such as 18-1535 from National Starch and Chemical Company; ethylene vinyl acetates and cellulose adhesives. In addition, natural and regenerated rubber adhesives; butyl rubber and polyisobutylene; nitrile rubber adhesives; and styrene and butadiene rubber adhesives are among the latex type adhesives that can be used. A third category of adhesives is the thermoplastic rubber adhesives of the block copolymer variety of A-B-A. In particular, we have found that polyvinyl alcohol (PVA) adhesives such as Adhesive No. 18-1535 manufactured by National Starch and Chemical Company of Bridgewater, New Jersey provide an appropriate base to reduce the adhesive used in our process. This adhesive can be used at full strength, at a viscosity of approximately 2500 centipoise to be used at 3.1 percent coverage of 1.59 millimeter points with a natural carrier sheet that has a basis weight of 4.40 kilograms per 836 square meters and a flow of air of approximately 56.63 to 60.07 liters per second.

* "Another suitable adhesive is CYCLOFLEX ™ L33-9600, also available from the National Starch and Chemical Company, for use with a basic weight carrier sheet of 4.40 kilograms per 836 square meters that has an air flow of approximately 56.63 to 60.07 liters. per second, this starch-based adhesive can be used within the scale of a viscosity of 50 to 700 centipoise, even when better performance is achieved near the lower end of this scale.

The viscosity of 50 to 200 centipoise is especially preferred with this adhesive. Generally speaking, adhesive viscosities within the 50 to 5000 centipoise scale can be used if appropriate paper types are selected. For viscosities outside the aforementioned scales, it has been found that the use of a lower viscosity adhesive results in excessive wrinkling while the higher viscosity adhesive does not produce satisfactory peel strength. between the carrier sheet and the third layer (shown for example, as the reference number 3 in Figures 1 and 2). DETAILED DESCRIPTION OF THE PROCESS y.- Returning now to the specific process conditions that can be used to carry out our invention, it must first be understood that an important aim is to provide laminates that not only have sufficient resistance to detachment between each layer to retain the layers together, but also, for most applications, to match the release resistances to avoid very large differences in the release resistance between the layers. different layers. This prevents the preferential delamination of one layer of the others, which in most cases is undesirable. More specifically, we have found that the ratio of the lowest average resistance of the detachment to the highest average resistance of the detachment should exceed 20 percent for the best results. The peel strength can be measured using a variety of equipment. It is preferred to measure the 180 ° peel strength using a tester Thwing-Albert Model 225-1 friction / detachment, manufactured by Thwing-Albert Instrument Company of Philadelphia, Pennsylvania. A 7.62 centimeter laminate strip is used since the variability tends to increase and thinner strips are tested. In the examples After that, two tests were carried out at a separation rate of 38.1 centimeters per minute for a period of time of 20 seconds, ensuring both average and maximum resistance of detachment in grams by a width of 7.62 centimeters. For comparison purposes, the peel strength measurements were made in two commercially available three layer laminates of 4.54 kilograms per 836 square meters manufactured by Lincoln Pulp and Paper Co. of Lincoln, Maine. The Lincoln laminates had been turned into napkins, having one tulip pattern and an intense yellow color and the other having a pattern of roses and an intense pink color. Three peel strength tests were carried out at each of the two joints between the layers. The so-called "T" tests measured the peel strength between the intermediate sheet and the upper layer while the so-called "B" tests measured the peel strength of the adhesive layer between the intermediate sheet and the lower sheet.

Yellow Tulip (Converted with Lincoln Laminate) (intense color) Resistance to Discharge - Maximum Release (Crest) Resistance Medium grams / 7.62 centimeters grams / 7.62 centimeters T 1. 11.8 4.8 2. 14.8 5.2 3. 16.9 5.5 B 1. 12.7 4.7 2. 12.4 5.5 3. 14.0 5.0 Color Pink Pink (Converted by Lincoln Laminate) (intensely colored) Resistance to Detachment - Resistance to Detachment Maximum Average (Crest) gr / 7.62 cm gr / 7.62 centimeters T 1. 13.3 3.5 2. 5.7 3.3 3. 7.4 3.5 B 1 10.9 4.7 2. 12.1 4.3 3. 9.5 4.3 Lincoln's three-layer laminate exhibited average shear strengths of approximately 3. 3 to 5.5 grams per 7.62 centimeters, a level that is generally considered suitable for commercial uses for these novel paper napkins. We have found that proper selection of raw materials and control of certain selected processing conditions is essential to successfully implement our invention. The most important parameters are the type of adhesive, the viscosity and the solidification time; adhesive coverage; basic weight of the carrier sheet and the air flow measured using the airflow test described above. We have found that proper adjustment of the parameters provides controlled penetration of the adhesives and allows the manufacture of multilayer laminates using only one adhesive application for the joints or multiple bonds between the layers. More specifically, when a carrier sheet with a lower air flow is used, it is generally necessary to reduce the viscosity of the adhesive, increase the coverage of the adhesive area or the size of the adhesive spots used, in order to ensure adequate penetration. For external sheets where penetration is not desired, a low air flow (preferably less than 23.60 liters per second) should be used. The solidification time of the adhesive should be such that the solidification does not occur between the point of application of the adhesive and the point of clamping above the lower calender roll. For most applications, adhesive coatings greater than 0.5 percent are suitable, and the pattern of the rubber mat must be selected accordingly.

EXAMPLES Following the procedures outlined above, three tests were carried out using layers of Shawano paper. The PVA adhesive from National Starch and Chemical Company number 18-1535 was used at full concentration. It had a viscosity of 2500 centipoise. The dot pattern shown in Figure 5 with 1.59 millimeter dots was used to provide an area coverage of 3.1 percent. In the following examples, the "T" peel strength tests measure the strength of the marked original adhesive pattern and represented by reference number 6 in Figure 1, while the peel strength marked "B" mediates the strength of the pattern of the penetration adhesive / "• complete marked with the reference number 7 in the Figure 1.

Example 1 5 The process of our invention was used to the conditions outlined above for manufacturing a three layer laminate paper Shawano EXtraBond ™ unconverted having a basis weight of 4.40 kilograms per 10,836 square meters and an airflow from 56.63 to 60.07 liters per second. The following results were obtained: Shawano Paper EXtraBond ™ - Not Converted Resistance 15 Resistance High Despren- Detachment (De dure Media Crest) g / 7.62 cm grams / 7.62 cm T 1. 132.1 30.6 20 2. 151.9 37.7 3. 156.1 34.9 B 1. 166.7 33.0 2. 93.0 24.6 25 3. 77.5 22.9 y. The peel strength of the resulting laminate was appreciably higher than that of the laminate converted by the Lincoln method commercially available. 5 Example 2 Stretch resistance tests were also carried out on the same three layer laminate 10 after becoming napkins. The following results were obtained: Shawano Paper EXtraBond ™ - Converted - no color Despren- resistance resistance Despren- 15 Maximum dure (De dure Media Crest) g / 7.62 cm gram / 7.62 cm T 1. 77.1 22.7 2. 102.1 25.7 20 3 3 .. 6 611..55 23.1 B 1. 55.4 9.3 2. 33.9 8.7 3. 40.3 12.9 25 -. Example 3 Field strength tests were also carried out on converted napkins of the same three layer laminate having a printed Minnie Mouse pattern. The following results were obtained: Shawano Paper EXtraBondTM - Converted - with color Resistance to Discharge - Resistance to Maximum Discharge (Average Crest Resistance) gr / 7.62 cm grams / 7.62 centimeters T 1. 115.3 24.9 2. 104.3 30.5 5 3. 99.7 25.3 B 1. 31.9 8.9 2. 56.2 12.2 3. 40.2 9.9 0 As the above examples demonstrate, our invention produces peel strengths in excess of those created by conventional processes using two steps of adhesive application.

In addition, the ratio of the resistance to detachment is in excess of 20 percent. It will be apparent that those skilled in the art can make many changes and modifications while remaining within the scope of our invention. We intend to protect all those laminates and equivalent processing methods, and limit our invention only as outlined in the following claims.

Claims (2)

REIVI DICACIONES

1. A paper rolling structure comprising a carrier sheet having a first ^ surface and a second surface; an initial adhesive pattern applied to the first surface; a third layer that remains above the second surface; a first layer that is below the adhesive pattern; and a full penetration adhesive pattern between the second surface of the carrier sheet and third layer created by controlled penetration of the initial pattern of the adhesive.

2. The paper laminate structure according to claim 1, wherein the ^ c > Peel strength of the full penetration adhesive pattern is at least about 20 percent of the peel strength of the initial adhesive pattern.