WO2005108050A1

WO2005108050A1 - Strap and methods for producing strap

Info

Publication number: WO2005108050A1
Application number: PCT/US2005/015487
Authority: WO
Inventors: Albert E. Cranston, Iii
Original assignee: Cranston Diversified Industries, Inc.
Priority date: 2004-05-04
Filing date: 2005-05-03
Publication date: 2005-11-17

Abstract

An elongate strap, or tape, having multiple reverse folds formed longitudinally therein to produce a somewhat sawtooth-shaped series of sheet sections to which adhesive is applied and then compressed together to form a substantially flat elongate strap. This strap has substantially flat upper and lower surfaces, yet has a desired degree of strength and rigidity for selected purposes. Methods for producing such a strap is also described wherein a flat sheet of material is formed into the generally sawtooth-shaped cross sectional configuration and compressed with adhesive thereon, to form such a tape, or strap.

Description

STRAP AND METHODS FORPRODUCING STRAP

Cross Reference to Related Application This application claims the benefit of U.S. Provisional Patent Application No. 60/568,146, filed May 4, 2004, which is hereby incorporated by reference.

Background This invention relates to an elongate strap and a method for producing such strap. Various forms of straps and tape are known, which may be used to connect objects, or to be formed in a loop around a bundle. In some prior machines and methods for applying a strap about a bundle, the strap, or tape, is formed in a loop around the bundle, is drawn taught thereabout, and the strap, or tape, has an adhesive thereon which may be activated to join opposite ends of the strap together for securing the bundle. In some instances, the adhesive coats the outer surfaces of the strap, and may be a heat activated adhesive which, when opposite ends of the strap are placed in contact with each other and heat and/or pressure is applied, they are bonded to each other. In the area of paper making, bales of stacked sheets of paper pulp are generally deposited in a bath which dissolves the pulp to form a slurry. The stacked sheets of paper pulp are typically strapped together, often using wire. Prior to depositing the pulp in the bath, the wires must be removed because the wire can damage the paper making machinery or contaminate the pulp slurry. The wire strap can be replaced with repulpable bands so that the entire bale of paper pulp, including the bands, can be placed in the bath. The repulpable bands are dissolved along with the pulp without damaging the equipment or contaminating the slurry. Repulpable straps of various configurations have been attempted in the past, but such have either been overly expensive and complex to manufacture, or have had other drawbacks. For example, one such prior strap has been produced of flat paper, or paper-like material which is formed of multiple sections folded back and over each other, with adhesive therebetween, and pressed together. Although such will produce a multi-layer folded strap, the multiple sections folded back and over each other produce substantially fully enclosed regions that do not provide easy escape of gases or other materials held between the adjacent sections. When heated or otherwise activated, bubbles may be produced between the layers, or other flaws may arise. Summary Disclosed below are representative embodiments that are not intended to be limiting in any way. Instead, the present disclosure is directed toward novel and nonobvious features, aspects and equivalents of the embodiments of strap and methods of producing strap described below. The disclosed features and aspects of the embodiments can be used alone or in various novel and nonobvious combinations and sub-combinations with one another. According to some embodiments, a sheet of material is formed with multiple reverse folds to produce a generally sawtooth-shaped series of folds, adhesive is applied thereto, and the sawtooth-shaped folds are pressed tightly against each other such that a substantially flat elongate strap, or tape, is provided with narrow adhered sections from which gases or other materials may easily escape, yet which provides a strap of substantial strength. One embodiment of an elongate strap comprises an elongate sheet of material formed with multiple reverse folds extending longitudinally of the strap with elongate sheet sections defined between the folds. The elongate strap also comprises a first sheet section that has a first width, which is measured laterally of the strap, and a second sheet section connected along a first edge thereof to a contiguous edge of the first sheet section at a first reverse fold. The second sheet section has a second width less than the first width and a second edge opposite the first edge. The elongate strap also includes a third sheet section that has a width greater than the second width and is connected along one edge of the third section to the second edge of the second sheet section at a second reverse fold. The strap can also comprise an adhesive between contiguous faces of the first and second sheet sections and between contiguous faces of the second and third sheet sections securing the first and second sheet sections together and securing the second and third sheet sections together. The material can be at least one of a biodegradable material, a repulpable material and/or a paper material. In some implementations, the third sheet section is connected along a first edge of the third sheet section to the second sheet section and the third sheet section has a second edge opposite its first edge. The elongate strap can comprise a fourth sheet section having a fourth width less than the third width. The fourth sheet section can be connected along one of its edges to the second edge of the third sheet section along a third reverse fold. The first, second and third reverse folds can be spaced apart laterally of the strap. The multiple sheet sections can be pressed tightly together to form a substantially flat strap and the first fold can be disposed between the third and second folds in a lateral direction of the flat strap. Alternate reverse folds can be oppositely directed to orient the sheet sections in a sawtoothlike pattern. The sheet of material can have opposed upper and lower sheet faces. A lower sheet face portion of the second sheet section can be adhesively secured to a lower sheet face portion of the first sheet section. An upper sheet face portion of the second sheet section can be adhesively secured to an upper sheet face portion of the third sheet section. In some implementations, the sheet of material has opposed longitudinal edges and a marginal edge portion of the sheet adjacent one longitudinal edge is folded along a fold line extending longitudinally of the sheet, back and onto an adjacent sheet portion and adhesively secured thereto. In some implementations, the strap has unexposed surfaces enclosed between adhesively secured sheet sections and exposed surfaces facing opposite sides of the strap and the exposed surfaces have an adhesive coating thereon. The adhesive can comprise a moisture activated adhesive. In some implementations, the adhesive comprises a heat sensitive adhesive which may be reactivated by the application of heat. The adhesive may be reactivated by application of heat in a temperature range of from 250 to 500 degrees Fahrenheit. The adhesive may also be reactivated by non-contact application of heat in a temperature range of from 300 to 700 degrees Fahrenheit. The adhesive can be selected from a group consisting of polyvinyl alcohol or other adhesives. One embodiment of an elongate strap comprises an elongate sheet of foldable material formed with multiple reverse folds extending longitudinally of the sheet and multiple elongate sheet sections bounded by the reverse folds. The elongate strap includes a pair of laterally spaced first and third sheet sections being main sheet sections. The first and third sheet sections each have a width of at least a first dimension. The strap includes a second sheet section intermediate and joining the first and third sheet sections which has a second width less than the first width. The second sheet section is adhesively secured along one of its faces to a contiguous surface of the first sheet section and the second sheet section is adhesively secured along an opposite face thereof to a contiguous surface of the third sheet section. In some implementations, alternate reverse folds of the strap can be oppositely directed to orient the first, second and third sheet sections in a sawtooth-like pattern. In some implementations, the multiple sheet sections can be pressed tightly together to form a strap which is substantially flat as viewed from an end thereof. In some implementations, the first sheet section can be connected along a first edge of the first sheet section to a first edge of the second sheet section along a first reverse fold. The third sheet section can be connected along a first edge of the third sheet section to a second edge of the second sheet section opposite its first edge along a second reverse fold. The third sheet section can also have a second edge opposite its the first edge. The strap can also comprise a fourth sheet section that has a fourth width less than the third width. The fourth sheet section can be connected along one of its edges to the second edge of the third sheet section along a third reverse fold. One embodiment of an elongate strap comprises an elongate sheet of foldable material formed with multiple reverse folds extending longitudinally of the sheet and multiple elongate sheet sections bounded by said reverse folds. The elongate sheet has a substantially flat central transition sheet section from which a first set of reverse folds directed generally in a first lateral direction away from the central transition sheet extend in the first lateral direction. A second set of reverse folds directed generally in a second lateral direction opposite the first lateral direction also extend from the central transition in the second lateral direction. The first and second set of reverse folds each include a pair of laterally spaced first and third sheet sections therebetween having a width of at least a first dimension. The first and second set of reverse folds also each include a second sheet section intermediate and joining the first and third sheet sections that has a second width less than the first width. Each second sheet section is adhesively secured along one of its faces to a contiguous surface of a respective first sheet section and each second sheet section is adhesively secured along an opposite face thereof to a contiguous surface of a respective third sheet section. Methods of producing and using the strap are also disclosed. One method for producing an elongate strap comprises providing an elongate sheet of foldable material and forming multiple reverse folds in the sheet. The folds extend longitudinally of the sheet with elongate sheet sections between adjacent folds and the reverse folds are spaced apart laterally of the sheet to produce a first sheet section having a first width measured laterally of the strap. The sheet can include a second sheet section connected along a first edge thereof to a contiguous edge of the first sheet section at a first reverse fold. The second sheet section can have a second width less than the first width and a second edge opposite the first edge. The reverse folds can produce a third sheet section that has a width greater than the second width connected along one edge of the third section to the second edge of the second sheet section at a second reverse fold. The method can also comprise applying adhesive between contiguous faces of the first and second sheet sections and between contiguous faces of the second and third sheet sections. The method further comprises pressing the sheet sections tightly together to secure the first and second sheet sections together and to secure the second and third sheet sections together. In some implementations of the method, the sheet has an upper surface and an opposed lower surface, and adhesive is applied to a major portion of the upper surface and the lower surface. The method can further comprise curing the adhesive. In some implementations, the method comprises tensioning the strap to draw the strap taut. The method also comprises applying the pressed elongate sheet directly around a bundle of material. One embodiment of an apparatus for producing an elongate strap comprises an elongate sheet of flexible foldable material. The apparatus can include at least one folding die configured to form multiple longitudinally extending folds in the elongate sheet. An adhesive applicator configured to apply an adhesive substantially consistently over upper and lower surfaces of the elongate sheet can also be included. In some implementations, the adhesive applicator comprises a sprayer configured to spray the adhesive. In some implementations, the adhesive applicator comprises an adhesive bath. The apparatus further comprises at least one pressing die configured to press at least portions of adjacent elongate sheet sections defined between the folds onto each other. In some implementations, the folding die can comprise a pair of forming rollers that have complementary sawtooth shaped circumferential forming surfaces. The apparatus can also include a setting station configured to set the adhesive. The setting station can set the adhesive using heat or microwave energy. In some implementations, the apparatus can comprise a cooling and tension setting station configured to cool the pressed elongate sheet to a desired temperature and tighten the pressed elongate sheet to a desired tension. In some implementations, the apparatus can include a doctoring or finishing roll set and a quality control station configured to sense irregular surfaces and measure characteristics of the pressed elongate sheet. In some implementations, the folding die can comprise a scoring device configured to form longitudinally extending score lines in the elongate sheet along which the longitudinally extending folds can be formed. The apparatus may further include a bundle of material around which the pressed elongate sheet is applied. According to some embodiments, a strap is simply and inexpensively produced and overcomes at least some of the problems existent in prior straps or tapes. According to some embodiments, the strap or tape has sufficient flexibility and stiffness such that it may be pushed or pulled by a drive mechanism along a curved track as needed to fulfill its intended purposes. According to some embodiments, the strap or tape is repulpable, such that upon completion of its useful activity it may be easily disposed of. The foregoing and other objects, features, and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures. Brief Description of the Drawings Fig. 1 is a schematic illustration of an apparatus for producing a strap, or tape, according to an embodiment of the present invention; Fig. 2 is a perspective view of a section of sheet material from which such strap is manufactured taken generally along the line 2-2 in Fig. 1 ; Fig. 3 is a partial sectional view taken generally along line 3-3 in Fig. 1 of rollers or anvils forming a plurality of reverse bends, or folds, in the sheet material in the forming process; Fig. 4 is a partial sectional view taken generally along line 4-4 in Fig. 1 showing schematically the spray application of adhesive to opposite sides of the formed sheet of material; Fig. 5 is a perspective illustration of a portion of the sheet of material in the region indicated at line 5-5 in Fig. 1 wherein forming rollers, or dies, have begun the process of compressing, or folding, the reverse bend sections downwardly in an intermediate part of the process; Fig. 6 is a perspective view of a portion of strap, or tape, taken along the line 6-6 in

Fig. 1 wherein the formed sheet of material has been compressed into a strap, or tape, according to an embodiment of the present invention; Fig. 7 is a perspective view similar to Fig. 6, but with folds extending in opposite directions on opposite sides of the longitudinal center line; Fig. 8 a schematic illustration of an apparatus for producing a strap or tape according to an embodiment of the present invention; Fig. 9 is a partial sectional view taken generally along line 9-9 in Fig. 8 of a scoring roll for controlling the location of the folds in a strap or tape; Fig. 10 is a partial sectional view taken generally along line 10-10 in Fig. 8 of rollers or anvils forming a plurality of reverse bends, or folds, in the sheet material in the forming process; Fig. 11 is a partial sectional view taken generally along line 11-11 in Fig. 8 of an initial press roll for folding the strap, or tape, along reverse bends, or folds, formed therein to an initial pressing configuration; Fig. 12 is a partial sectional view taken generally along line 12-12 in Fig. 8 of a i n intermediate press roll for folding the strap, or tape, along reverse bends, or folds, formed therein to an intermediate pressing configuration; Fig. 13 is a partial sectional view taken generally along line 13-13 in Fig. 8 of a final press roll for folding the strap, or tape, along reverse bends, or folds, formed therein to a fully compressed configuration; Fig. 14 is a partial sectional view taken generally along line 14-14 in Fig. 8 of a doctoring roll and a glazing roll for finalizing the strap, or tape, shape and size prior to inspection; and Fig. 15 is a sectional view of a portion of strap, or tape, wherein the formed sheet of material has been compressed into a strap, or tape, having a plurality of substantially flat intermediate portions.

Detailed Description Referring to the drawings, and first more particularly to Figs. 1 and 2, an elongate sheet of flexible foldable material 10 is shown being pulled from a roll 12 toward a pair of forming dies, or rollers, 14A, 14B. As best seen in Fig. 3, the forming 'dies 14A, 14B have complementary sawtooth shaped circumferential forming surfaces 16A, 16B respectively. Each of rollers 14A, 14B is somewhat conical in shape, in that roller 14A has its larger diameter section at the left in Figs. 1 and 3 and its smaller diameter section at the right in Figs, land 3. Conversely, roller 14B has its smaller diameter section at the left in Figs. 1 and 3 and progresses to a larger diameter section adjacent its right in Figs. 1 and 3. Although rollers 14A, 14B are illustrated somewhat separated in Fig. 3, it should be recognized that in use they would be fairly tightly pressed against each other, or toward each other, so that they would form sheet material 10 therebetween into the general configuration illustrated in Fig. 3. Rollers 14A, 14B have been separated in Fig. 3 for illustrative purposes so that the configuration of their peripheral surfaces and the configuration into which sheet material 10 is formed thereby are more readily visible. Referring to Figs. 2-4, sheet 10 has an upper surface 10a and a lower surface 10b. It also has opposite longitudinally extending side edges, or margins, 10c, lOd. The sheet on roll 12 and as moving into the forming process has an initial width Wi. In the initial forming, which occurs in the region illustrated in Fig. 3, sheet 10 is formed with a plurality of reverse folds, or bends, extending longitudinally of the strap or sheet of material. These reverse folds are indicated at 20a, 20b, 20c, 20d, 20e, 20f, 20g, 20h, 20i, 20j, 20k. Additional folds are indicated generally at 20€, 20m, 20n and 20p respectively. Defined between the various folds are a plurality of sheet sections 22a, 22b, 22c, 22d, 22e, 22f, 22g, 22h, 22i, 22j, 22k, 22£. Edge margin sheet sections are noted 22m, 22n. Although a single pair of forming dies, or rollers, 14A, 14B have been shown for forming the reverse folds, or bends, it should be understood that stationary anvils, or dies, may be used also. It also may be necessary to form the reverse bends, or folds, in a multistage process in which score lines are provided extending longitudinally of the strap material, and then partial folds are made which then progress into full folds, or bends, as shown in Figs. 3-6. For example, in one embodiment, as shown in Figs. 8 and 9, the reverse folds, or bends, can be initiated by passing the strap material 10 through a scoring device 120 to form grooves, or score lines 32, at locations on the strap material where the strap will be folded. The grooves assist in controlling the actual location of the folds formed in the strap material 10 by one or more pairs of forming dies as described above. The scoring device 120 includes rotatable scoring disks 126 coupled to an axial rod 124 and configured to extend a predetermined distance beyond an upward facing surface of the strap material 10 as it passes through the device with assistance from strap material guide 122. In some embodiments the scoring device can be a rotating scoring roll having multiple circular protrusions extending around its periphery which interact with the strap material to form the score lines in the strap material. Although the forming dies 14A, 14B shown in Fig. 1 are somewhat conical in shape, in some embodiments, the strap producing apparatus includes forming dies 130A, 130B that are generally cylindrical in shape as shown in Figs. 8 and 10. Due to the sawtooth-shaped configuration produced in the sheet by forming rollers

14A, 14B, sheet sections 22a, 22c, 22e, 22g, 22i, 22k have a width indicated generally at W₃ which is greater than a general width indicated at W₄ for sheet sections 22b, 22d, 22f, 22h, 22j, 22£. In the configuration illustrated, a first elongate edge of one of the wider sheet sections, such as 22a is joined, or connected, along a first edge to a contiguous edge of a second sheet section, such as that indicated at 22b along reverse fold line 20a. Similarly, a second edge of sheet section 22b is connected, or joined, along reverse fold line 20b to an elongate longitudinally extending contiguous edge of sheet section 22c. Further, the opposite elongate longitudinal edge of sheet section 22c is joined, or connected, at reverse fold 20c to a contiguous edge of sheet section 22d. This relationship of adjacent sheet sections being connected to each other along reverse fold lines continues across the width of the sheet. Further, it will be seen that lower sheet face portions of contiguous sheet sections

(which are portions of lower surface 10b) are placed in facing relationship to each other and upper sheet face portions of contiguous sheet sections (which are portions of upper surface

10a) face each other. Explaining further, and as an example, the lower sheet face portion of sheet section 22a faces the lower sheet face portion of sheet section 22b, and the lower sheet face portion of sheet section 22c faces the lower sheet face portion of section 22d.

Similarly, the upper sheet face portion of sheet section 22b faces the upper sheet face portion of sheet section 22c, and the upper sheet face portion of section 22d faces the upper sheet face portion of section 22e. In the region indicated 4-4 in Fig. 1 and in Fig. 4, a pair of opposed upper and lower adhesive spray heads 28 A, 28B are directed toward the upper and lower surfaces of sheet

10, respectively, and as indicated by the vertically disposed arrows 29 can spray an adhesive substantially consistently over both the upper and lower surfaces of the formed sheet. The adhesive may be a heat sensitive adhesive, which may be reactivated by the application of heat. Such may be reactivated by the application of heat in a temperature range of 250-500°

Fahrenheit, or more particularly in a temperature range of from 300-400° Fahrenheit.

Although not intended to be limited hereby, the adhesive may be selected from a group consisting of polyvinyl alcohol. Other adhesives may be applied also. A further example, but not to be considered limiting, would be a moisture activated adhesive. Although spray heads are illustrated in Fig. 1 as dispensing a spray of adhesive onto upper and lower surfaces of the sheet, in some embodiments, as illustrated in Fig. 8, the opposed surfaces of the sheet also may be coated with an adhesive by dipping the sheet 10 in a bath of adhesive 144 stored in container 140. The container 140 can have a stationary idler 142 for facilitating even application of the adhesive 144 to the sheet and removal of excess adhesive prior to folding the sheet. Alternatively, in some embodiments, the adhesive can be applied to the sheet via a transfer roller. After having the adhesive applied to opposed upper and lower surfaces of the sheet, the sawtooth-shaped section is passed through compression rollers, or dies, as indicated schematically at section 5-5 in Fig. 1 to compress the sheet sections into a finished strap. Explaining further, the formation of the initial sawtooth configuration as illustrated in Figs. 3 and 4 may require several successive dies, or rollers, as opposed to the single set of rollers, or dies, illustrated in Fig. 1. Similarly, the compression, or flattening, of the corrugated strip from the sawtooth configuration illustrated in Figs. 3 and 4 to a substantially flattened configuration as illustrated in Fιg.6 could take multiple successive sets of dies, or rollers, rather than the single set illustrated in Fig. 1. In Fig. 5, an initial compression step is illustrated. Here the reverse folded sheet sections are shown beginning to be bent over, or compressed, toward their final configuration. Also, edge margin portions 22m, 22n of the sheet adjacent edges 10c, lOd, are folded over along fold lines 20m, 20n, in the directions illustrated by the dashed arrows. When finally compressed, the strap has the general configuration as illustrated in Fig. 6. The strap would be compressed to a substantially flat strap, having an overall thickness generally equal to approximately two times the thickness of sheet 10, such as even if there are three or more overlapped portions (see Fig. 6). However, the thickness of the folded over sections are exaggerated m the drawings for purposes of illustration to show the configuration of the strap. As is best seen in Fig. 6, contiguous faces of folded over portions, or sheet sections, are pressed into adhesive securement with each other, such as contiguous lower facing surfaces of sheet sections 22a and 22b, contiguous upper facing surfaces of sheet sections 22b, 22c, contiguous lower facing surfaces of sections 22c, 22d, etc. As is seen also in Fig. 6, since those sheet sections which are illustrated extending upwardly (as viewed progressing from left to right in Figs. 3-5) have a greater width W₃ than the width W₄ of those sheet sections which extend downwardly, the fold lines 20a-20k are spaced apart laterally from each other across the width of the final formed strap 30. Further, there are both enclosed sheet section surfaces which are adhered together and exposed upper and lower surfaces which remain open and visible from the exterior of the tape. For example, in Fig. 6 the upper exposed surface portions of sections 20a, 20c, 20e, respectively, are visible and may be pressed against adjacent materials if necessary. The marginal edge portions 20m, 20n have been folded back to provide substantially consistent thickness and strength throughout the width of the strap 30 to outer edges 30a, 30b of the strap, respectively. Referring to Fig. 7, a sheet 10A has been folded into an elongated strap 30A having a plurality of reverse folded sheet sections somewhat similar to that illustrated in Fig. 6. However, it will be seen in Fig. 7 that the reverse folded sheet sections to the right side of the longitudinal center line in Fig. 7 are directed generally to the right, while the reverse folded sheet sections to the left of the longitudinal center line are directed generally to the left. A substantially flat intermediate portion 30B at the longitudinal center forms a transition between the right-directed folded sheet sections and the left-directed folded sheet section. Otherwise the strap, or tape, 30A is similar to that described above, and is produced in substantially the same manner. Referring now to Fig. 1 , and describing in greater detail the process for producing such a strap, a sheet of foldable material, such as paper or other acceptable materials for making such a strap, 10 is drawn from a roll 12 and moved in the direction of arrow 34 into forming dies, or rollers, such as those indicated at 14A, 14B. Although only two forming dies, or rollers, are illustrated, it should be understood that a series of rollers, or dies, may be required to produce the desired cross-section for the initial configuration of the strap material. Explaining further, forming dies, or rolls, may be placed in succession along the path of the sheet material to gradually form the sheet material into the desired corrugated sawtooth-shaped configuration illustrated in cross-section in Figs. 3 and 4. After passing through the forming dies, or rollers, 14 A, 14B, the strip, or sheet, of material in its sawtooth-shaped corrugated form passes between upper and lower adhesive spray heads 28A, 28B. Adhesive is sprayed onto the entire upper and lower surfaces of sheet 10 as illustrated in Fig. 4. Although a spray application of adhesive is illustrated here, it should be recognized that the adhesive may be applied in other manners, such as in a coating bath. The adhesive, with which the strap material is coated, may be chosen from a number of types, such as, but not limited to, a moisture activated or heat sensitive adhesive which is reactivated by the application of heat. The adhesive may be such as is reactivated in a temperature range from 250-500° Fahrenheit, and more particularly in a temperature range of from 300-400° Fahrenheit. One form of adhesive that may be selected may be from a group consisting of polyvinyl alcohol. However, other adhesives may be found to be appropriate also. After receiving the coating of adhesive on the upper and lower surfaces, the strip of material is passed through at least a pair of upper and lower pressing dies, or rollers, 38A, 38B. Although only one pair of pressing rollers, or dies, are illustrated, the process may include a number of such rollers, or dies, which progressively compress, or press the adjacent sheet sections down and onto each other from the initial pressing configuration as illustrated in Fig. 5 to the fully compressed configuration illustrated in Fig. 6. For example, as shown in Figs. 8 and 11, compression of the sheet 10 to the initial pressing configuration, can be performed by an initial press roll 150. As shown in Figs. 8 and 12, from the initial press roll 150, the sheet 10 at the initial compression stage advances into an intermediate press roll 160 to further compress, or press the sheet to an intermediate pressing configuration. Then, the sheet 10 at the intermediate pressing configuration advances into a final press roll 170, as shown in Figs. 8 and 13, to further compress, or press the sheet to the fully compressed configuration. The initial press roll 150, the intermediate press roll 160 and the final press roll 170 can each include a roller 152, 162, 172, respectively, roll axle 154, 164, 174, respectively, and a roll guide 156, 166, 176, respectively. Although the strap forming apparatus of Fig. 8 show three pairs of pressing rollers, or dies, it is recognized that two or more than three pairs can be used to progressively compress, or press the sheet into the fully compressed configuration. As the corrugated sawtooth-shaped configuration of the adjacent sheet sections are pressed against each other, marginal edge portions 20m, 20n adjacent edges 10c, lOd are folded back on each other, around fold lines 20m, 20n as noted by the dashed arrows in Fig. 5 to form double thickness edge portions 30a, 30b, as shown in Fig. 6. The pressing, or compressing, dies or rollers compress the adjacent sheet sections to a configuration as illustrated in Fig. 6, such that facing and contiguous face surface portions of adjacent sheet sections are adhesively secured to each other by the adhesive applied thereto by spray applicators 28A, 28B. As is seen, in the finally prepared strap 30 as shown in Fig. 6, the multiple reverse folds extend longitudinally of the strap thus produced with the folds spaced apart laterally of the strap. Further, there are substantial areas of exposed upper and lower surfaces of the sheet sections on which adhesive exists, and which can be used to adhesively secure the strap to other materials as desired later. The strap thus formed is a laminated ribbon, or strap, having a cross-section in which one sheet section is compressed diagonally onto another. The edge margin portions have been folded back to close the edges, and provide basically consistent thickness for the ribbon, or strap, from one side to the other. Although the exaggerated showing of the overlapping sheet section in Fig. 6 illustrates a somewhat uneven upper and lower surface, it should be recognized that when the strap has been firmly compressed, the upper and lower surfaces will be substantially flat and the overall strap will have a thickness which is substantially equal to two or more times the thickness of the sheet material from which it is produced. After compressing to the configuration illustrated in Fig. 6 by rollers, or dies 38 A, 38B, the strap, tape, or ribbon, passes through a setting station 40 in which the adhesive is set either by heat or use of microwave energy. The strap passes around a large drum 42, or in the alternative could be carried through a belted conveyor press. The strap then continues along its path through a cooling and tension setting tunnel 46. In this apparatus, the adhesive is cooled and the strap is drawn taught to a selected tension by a tension adjustment, or tension inducing, roller 48 at the downstream end of tunnel 46. From the tension inducing roller 48, the strap continues through a quality control station 50. In the quality control station, various characteristics of the strap produced in this process are measured. These include the dimensions of the strap, moisture, surface features, ^■ etc. In some embodiments, the sheet 10 can pass through doctoring and glazing rolls 180 prior to entering the quality control station 50 (see Fig. 8). Generally, the doctoring and glazing rolls 180 function to finalize the size and shape of the sheet 10 to form completed strap 30 for final inspection by the quality control station 50. The doctoring and glazing rolls 180 can comprise a pair of rollers 182A, 182B, and a pair of rollers 184A, 184B, for reshaping and polishing the top and bottom, and side surfaces, respectively, of the strap 10. In specific embodiments, the strap then continues to be coiled onto a reel at 52 (Fig. 1). In other specific embodiments, the strap 30 formed by the process illustrated could be taken directly from quality control station 50, and rather than being coiled onto a reel as shown in Fig. 1, it could be applied directly to a package or bundle 190 comprised generally of compressed material (Fig. 8). For normal strapping of bundles for packages, the most common width of finished tape W₂ would probably be in a range of one-quarter inch to two-and-one-half inches wide. However, it could be foreseen that much greater widths may be desired for certain applications ranging up to width W₂ in excess of 30 inches. A strap 30 as provided by the apparatus and process noted above, and as illustrated in the figures, is particularly well adapted for use in strapping bundles, for use in a turn-up system in the paper making industry, for paper bag handles, and numerous other applications. In use in banding or strapping of bundles, the selected flexibility and longitudinal rigidity of the strap allows it to be carried in a channel guide to be wrapped about a bundle . with opposite end portions of the strap placed in juxtaposition and the strap drawn taught about the bundle. After the strap is drawn taught around the bundle, the juxtaposed portions of the strap are placed in face-to-face position, heat and pressure are applied to reactivate the heat sensitive adhesive, and the two ends of the strap thus are adhesively joined to tie the bundle together. In the paper making industry, turn-up tape is used to separate together the trailing end of one section of paper, and the leading end of a following section of paper to make up the next roll. The present tape may serve this function also. The strip of foldable material from which the present tape may be manufactured may be any material which may be folded and formed as set out herein. In one embodiment, the strap, tape, or band preferably would be constructed entirely of repulpable paper formed in the configuration described. By being repulpable, it solves problems experienced when using straps made of other materials which are not easily recycled. In other forms it may be a biodegradable material, or it may be made from plastic film or sheet material. By providing only portions of the sheet sections which are adhesively secured together in minor, or narrow, sections of the strap, not only is a strap provided having the desired characteristics of strength, flexibility and adhesive exposed on its upper and lower surfaces, but also it features a minimum of overlapping portions. This allows for better fiber-to-fiber adhesion without gas or heat bubbles or pockets being trapped between the layers of folded over sections, as each fold has an escape route open to venting. In Fig. 15, the sheet 10 can be folded into an elongated strap 30C having a plurality of reverse folded sheet sections somewhat similar to that of elongated strap 30 A illustrated in Fig. 7. However, the elongated strap 30C includes multiple substantially flat intermediate portions 30D. The configuration of the reverse folded sheets of elongated strap 30C is particularly conducive to venting gas or heat bubbles by providing a centralized escape route between adjacent intermediate portions 30D. Additionally, the configuration of elongated strap 30C results in a strap thickness equal to three layers of sheet material 10 across substantially the entire width of the strap, which translates into a strap having three times the tensile strength of a single layer of sheet material and more tensile strength than other folded strap configurations. In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. We therefore claim as our invention all that comes within the scope and spirit of these claims.

Claims

Claims:

1. An elongate strap comprising an elongate sheet of material formed with multiple reverse folds extending longitudinally of the strap with elongate sheet sections defined between said folds, a first sheet section having a first width measured laterally of the strap, a second sheet section connected along a first edge thereof to a contiguous edge of said first sheet section at a first reverse fold, said second sheet section having a second width less than said first width and a second edge opposite said first edge, a third sheet section connected along one edge of said third section to the second edge of the second sheet section at a second reverse fold and having a width greater than said second width, and adhesive between contiguous faces of said first and second sheet sections and between contiguous faces of said second and third sheet sections securing said first and second sheet sections together and securing said second and third sheet sections together.

2. The strap of claim 1 , wherein said third sheet section is connected along a first edge of the third sheet section to said second sheet section and said third sheet section has a second edge opposite its said first edge, and which further comprises a fourth sheet section having a fourth width less than said third width, said fourth sheet section connected along one of its edges to said second edge of the third sheet section along a third reverse fold.

3. The strap of claim 2, wherein said first, second and third reverse folds are spaced apart laterally of said strap.

4. The strap of claim 3, wherein said multiple sheet sections are pressed tightly together to form a substantially flat strap and wherein said first fold is disposed between said third and second folds in a lateral direction of said flat strap.

5. The strap of claim 3, wherein alternate reverse folds are oppositely directed to orient said sheet sections in a sawtooth-like pattern.

6. The strap of claim 2, wherein said sheet of material has opposed upper and lower sheet faces, and wherein a lower sheet face portion of said second sheet section is adhesively secured to a lower sheet face portion of said first sheet section, and an upper sheet face portion of said second sheet section is adhesively secured to an upper sheet face portion of said third sheet section.

7. The strap of claim 1, wherein said sheet of material has opposed longitudinal edges and a marginal edge portion of said sheet adjacent one longitudinal edge is folded along a fold line extending longitudinally of said sheet, back and onto an adjacent sheet portion and adhesively secured thereto.

8. The strap of claim 1, wherein said adhesive comprises a heat sensitive adhesive which may be reactivated by the application of heat.

9. The strap of claim 8, wherein said adhesive may be reactivated by application of heat in a temperature range of from 250 to 500 degrees Fahrenheit.

10. The strap of claim 8, wherein said adhesive may be reactivated by application of heat in a temperature range of from 300 to 400 degrees Fahrenheit.

11. The strap of claim 8, wherein said adhesive is selected from a group consisting of polyvinyl alcohol.

12. The strap of claim 1, wherein said adhesive comprises a moisture activated adhesive.

13. The strap of claim 1, wherein said strap has unexposed surfaces enclosed between adhesively secured sheet sections and exposed surfaces facing opposite sides of said strap and said exposed surfaces have an adhesive coating thereon.

14. The strap of claim 1, wherein said material comprises at least one of a biodegradable material, a repulpable material or a paper material.

15. An elongate strap comprising an elongate sheet of foldable material formed with multiple reverse folds extending longitudinally of the sheet and multiple elongate sheet sections bounded by said reverse folds, with a pair of laterally spaced first and third sheet sections being main sheet sections, each having a width of at least a first dimension, and with a second sheet section intermediate and joining said first and third sheet sections having a second width less than said first width, and said second sheet section is adhesively secured along one of its faces to a contiguous surface of said first sheet section and said second sheet section is adhesively secured along an opposite face thereof to a contiguous surface of said third sheet section.

16. The strap of claim 15, wherein alternate reverse folds are oppositely directed to orient said first, second and third sheet sections in a sawtooth-like pattern.

17. The strap of claim 15, wherein said multiple sheet sections as pressed tightly together to form a strap which is substantially flat as viewed from an end thereof.

18. The strap of claim 15, wherein said first sheet section is connected along a first edge of the first sheet section to a first edge of said second sheet section along a first reverse fold, and said third sheet section is connected along a first edge of the third sheet section to a second edge of said second sheet section opposite its first edge along a second reverse fold, and said third sheet section has a second edge opposite its said first edge, and which further comprises a fourth sheet section having a fourth width less than said third width, said fourth sheet section connected along one of its edges to said second edge of the third sheet section along a third reverse fold.

19. The strap of claim 18, wherein said first, second and third reverse folds are spaced apart in a direction extending laterally of said strap.

20. The strap of claim 19, wherein said multiple sheet sections are pressed tightly together to form a substantially flat strap and wherein said first reverse fold is disposed between said third and second reverse folds in a lateral direction of said flat strap.

21. The strap of claim 18, wherein said sheet of material has opposed upper and lower sheet faces, and wherein a lower sheet face portion of said second sheet section is adhesively secured to a lower sheet face portion of said first sheet section, and an upper sheet face portion of said second sheet section is adhesively secured to an upper sheet face portion of said third sheet section. U

22. The strap of claim 21 , wherein the upper sheet face portion of said third sheet section is adhesively secured to an upper sheet face portion of said fourth sheet section.

23. The strap of claim 22, wherein said fourth sheet section is connected along a first edge of the fourth sheet to a second edge of said third sheet, and which further comprises a fifth sheet section having a fifth width greater than said fourth width, said fifth sheet section connected along one of its edges to a second edge of said fourth sheet opposite its first edge.

24. The strap of claim 23, wherein a lower sheet face portion of said fourth sheet section is adhesively secured to a lower sheet face portion of said fifth sheet section, and wherein the first sheet section comprises a first substantially flat intermediate section, the third sheet section compπses a second substantially flat intermediate section, and the fifth sheet section comprises a third substantially flat intermediate section, and wherein exposed surfaces of the first and third intermediate sections face a direction generally opposite that of an exposed surface of the second intermediate section.

25. The strap of claim 15, wherein said sheet of mateπal has opposed longitudinal edges and a marginal edge portion of said sheet adjacent one longitudinal edge is folded over along a fold line extending longitudinally of said sheet, back and onto an adjacent sheet portion and adhesively secured thereto.

26. The strap of claim 15, wherein said adhesive comprises a heat sensitive adhesive which may be reactivated by the application of heat.

27. The strap of claim 15, wherein said strap has unexposed surfaces enclosed between adhesively secured sheet sections and exposed surfaces facing opposite sides of said strap and said exposed surfaces have an adhesive coating thereon.

28. The strap of claim 15, wherein said material comprises at least one of a biodegradable material, a repulpable material or a paper material.

29. A method for producing an elongate strap comprising: providing an elongate sheet of foldable material; forming multiple reverse folds in said sheet, said folds extending longitudinally of said sheet with elongate sheet sections between adjacent folds, said reverse folds being spaced apart laterally of said sheet to produce a first sheet section having a first width measured laterally of the strap, a second sheet section connected along a first edge thereof to a contiguous edge of said first sheet section at a first reverse fold, said second sheet section having a second width less than said first width and a second edge opposite said first edge, and a third sheet section having a width greater than said second width connected along one edge of said third section to the second edge of the second sheet section at a second reverse fold; applying adhesive between contiguous faces of said first and second sheet sections and between contiguous faces of said second and third sheet sections; and pressing said sheet sections tightly together to secure said first and second sheet sections together and to secure said second and third sheet sections together.

30. The method of claim 29, wherein said sheet has an upper surface and an opposed lower surface, and adhesive is applied to a major portion of said upper surface and said lower surface.

31. The method of claim 29, further comprising curing said adhesive.

32. The method of claim 29, further comprising tensioning said strap to draw said strap taut.

33. The method of claim 29, wherein said adhesive comprises a heat sensitive adhesive which may be reactivated by the application of heat.

34. The method of claim 29, wherein said strap is formed with unexposed surfaces enclosed between portions of said first and second sheet sections which are secured together and between portions of said second and third sheet sections which are secured together, and exposed surfaces facing opposite sides of said strap, and which further comprises the step of applying adhesive to said exposed surfaces.

35. The method of claim 29, wherein forming multiple reverse folds in said sheet comprises said third sheet section being connected along a first edge of the third sheet section to said second sheet section and said third sheet section having a second edge opposite its said first edge, and a fourth sheet section having a fourth width less than said third width being connected along one of its edges to said second edge of the third sheet section along a third reverse fold.

36. The method of claim 35, wherein said first, second and third reverse folds are spaced apart laterally of said strap.

37. The method of claim 36, wherein said multiple sheet sections are pressed tightly together to form a substantially flat strap and wherein said first fold is disposed between said third and second folds in a lateral direction of said flat strap.

38. The method of claim 36, wherein alternate reverse folds are oppositely directed to orient said sheet sections in a sawtooth-like pattern.

39. The method of claim 35, wherein said sheet of material has opposed upper and lower sheet faces, and wherein a lower sheet face portion of said second sheet section is adhesively secured to a lower sheet face portion of said first sheet section, and an upper sheet face portion of said second sheet section is adhesively secured to an upper sheet face portion of said third sheet section.

40. The method of claim 29, wherein said sheet of material has opposed longitudinal edges and a marginal edge portion of said sheet adjacent one longitudinal edge is folded along a fold line extending longitudinally of said sheet, back and onto an adjacent sheet portion and adhesively secured thereto.

41. The method of claim 29, wherein said strap is formed with unexposed surfaces enclosed between adhesively secured sheet sections and exposed surfaces facing opposite sides of said strap and an adhesive coating is applied to said exposed surfaces.

42. The method of claim 29, wherein said material comprises at least one of a biodegradable material, a repulpable material or a paper material.

43. The method of claim 29, further comprising applying the pressed elongate sheet directly around a bundle of material.

44. An apparatus for producing an elongate strap comprising: an elongate sheet of flexible foldable material; at least one folding die configured to form multiple longitudinally extending folds in the elongate sheet; an adhesive applicator configured to apply an adhesive substantially consistently over upper and lower surfaces of the elongate sheet; and at least one pressing die configured to press at least portions of adjacent elongate sheet sections defined between the folds onto each other.

45. The apparatus of claim 44, wherein the at least one folding die comprises a pair of forming rollers having complementary sawtooth shaped circumferential forming surfaces.

46. The apparatus of claim 44, wherein the adhesive applicator comprises a sprayer configured to spray the adhesive.

47. The apparatus of claim 44, wherein the adhesive applicator comprises an adhesive bath.

48. The apparatus of claim 44, further comprising a setting station configured to set the adhesive.

49. The apparatus of claim 44, wherein the setting station sets the adhesive using heat or microwave energy.

50. The apparatus of claim 44, further comprising a cooling and tension setting station configured to cool the pressed elongate sheet to a desired temperature and tighten the pressed elongate sheet to a desired tension.

51. The apparatus of claim 44, further comprising doctoring and glazing rolls for reshaping and polishing the pressed elongate sheet.

52. The apparatus of claim 44, further comprising a quality control station configured to measure characteristics of the pressed elongate sheet.

53. The apparatus of claim 44, wherein the at least one folding die comprises a scoring device configured to form longitudinally extending score lines in the elongate sheet along which the longitudinally extending folds can be formed.

54. The apparatus of claim 44, further comprising a bundle of material around which the pressed elongate sheet is applied.

55. An elongate strap comprising an elongate sheet of foldable material formed with multiple reverse folds extending longitudinally of the sheet and multiple elongate sheet sections bounded by said reverse folds, the elongate sheet having a substantially flat central transition sheet section from which a first set of reverse folds directed generally in a first lateral direction extend away from the central transition sheet in the first lateral direction and from which a second set of reverse folds directed generally in a second lateral direction opposite the first lateral direction extend away from the central transition in the second lateral direction, wherein the first and second sets of reverse folds each include a pair of laterally spaced first and third sheet sections therebetween having a width of at least a first dimension, and the first and second sets of reverse folds each include a second sheet section intermediate and joining the first and third sheet sections having a second width less than the first width, each second sheet section is adhesively secured along one of its faces to a contiguous surface of a respective first sheet section and each second sheet section is adhesively secured along an opposite face thereof to a contiguous surface of a respective third sheet section.