Not Applicable.
Not Applicable.
1. Technical Field
This invention relates to a roll of paperband wherein the paperband includes longitudinal indentations and transverse undulations to create a corrugated structure to control stiffness and flexibility of the band as desired.
2. Prior Art
It is a common practice in the papermaking and packaging industries to employ a paperband or strap that is loaded into a channel of a track assembly and then removed rapidly out of the channel and employed to cut and spool a web of paper onto an empty spool or to be used to wrap around and secure a load, container or a bundle of material. Because the paperband should be stiff enough to be pushed into the channel from one end thereof, the band may twist or otherwise be distorted or separated during upward movment that is accomplished by a “stripping” action during removal from the paperband track assembly. This becomes a very important consideration in those applications where the width of the channel opening is made less than the width of the band or tape and the lower tape-carrying guide way of the channel in order to cover and carry the tape. An improved paperband is disclosed herein that greatly reduces the distortion and crimping common to prior art paperbands, reduces the wear on the guide way channel and its cover, and also reduces the separation of layers in some bands made from multiple layers.
Examples of the prior art include U.S. Pat. No. 5,816,526, which discloses multi-ply folded strip held together by adhesive. U.S. Pat. No. 3,126,312 discloses a plurality of elongate members aligned in a plane and held together by adhesive. U.S. Pat. No. 4,414,258 discloses a woven ribbon made of flat strips and weft filaments, which are held in place by adhesive.
U.S. Patent Publication No. 2004/0131825 A1 (Jul. 8, 2004) discloses a strap constructed of a double layer of elongated paper elements secured with adhesive on at least a portion of the strap.
None of the above-described paper devices is satisfactory for use in a paperband track assembly beneath wide paper machines for the reason that they do not have the required stiffness for such use.
In one aspect of the present invention there is provided a roll of paperband adaptable for use in paper web cutting and turn-up systems or for use in baling, the paperband comprising an elongate multi-ply board having upper and lower surfaces, and a center portion and spaced reduced side portions, each side portion having an inside edge portion and an outside edge portion, each inside edge portion being defined by an elongate longitudinal first groove between the center portion and respective side portion. Each side portion is folded about the respective groove to dispose each side portion in contact with an adjacent portion of the center portion. The side edge portions are located generally medially of the center portion. The paperband includes transverse undulations to enable the multi-ply board to be formed into a roll of paperband without materially affecting its tensile strength. The side edge portions are located closely adjacent each other without any overlap therebetween so that a longitudinal line of weakness is formed therebetween. An adhesive layer is located between each side edge portion and the center portion. An adhesive coating may be located on one surface or both surfaces of the paperband when the paperband is used for baling, depending on the type of adhesive. The undulation parameters are defined by and chosen to increase or decrease stiffness and stretchability. The undulations are provided on the upper and lower surfaces of the paperband. The adhesive layer is water-soluble. The side edge portions are in abutment with each other when said paperband is used for baling.
In another aspect of the present invention there is provided a roll of paperband adaptable for use in paper web cutting and turn-up systems or for use in baling, the paperband including an elongate multi-ply board having upper and lower surfaces, and a center portion and spaced reduced side portions, each side portion having an inside edge portion and an outside edge portion, each inside edge portion being defined by an elongate longitudinal first groove between the center portion and respective side portion, each side portion being folded about respective groove to dispose each side portion in contact with an adjacent portion of the center portion. The side edge portions are located generally medially of the center portion to be located closely adjacent each other without any overlap therebetween so that a longitudinal line of weakness is formed therebetween to provide for longitudinal bending of the paperband about the line of weakness when the paperband is pulled from a track assembly. The paperband includes transverse undulations to enable the multi-ply board to be formed into a roll of paperband without materially affecting its tensile strength. There is also a coating of adhesive for securing the folded side portions to the center portion. The board includes several plies formed of cellulose fibers. The side edge portions preferably are in abutment with each other when the paperband is used for baling. The corrugations are formed to shorten the length of the paperband to provide a shock-absorbing function to minimize tearing of the paperband when tensile force is applied to the paperband.
In a further aspect of the present invention a roll of paperband adaptable for use in paper web cutting and turn-up systems or for use in baling, the paperband being formed of an elongate multi-ply board having upper and lower surfaces, and a center portion and spaced reduced side portions, each side portion having an outside edge portion, each side portion being folded to dispose each side portion in contact with an adjacent portion of the center portion, the outside edge portions being located generally medially of the center portion. The paperband includes transverse undulations to enable the multi-ply board to be formed into a roll of paperband without materially affecting its tensile strength. The outside side edge portions are located closely adjacent each other without any overlap therebetween so that a longitudinal line of weakness is formed therebetween.
The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
Introduction
The paperband disclosed herein is formed of a multi-ply board made by a multi-ply board machine with a chemical composition, weight and thickness selected for a particular application. As a general proposition however, the high degree of stiffness of a multi-ply board does not allow of a tun-up paperband cutting tape.
The present paperband includes a series of staggered transverse indentations, undulations or formations that result in a “corrugated” profile and provide the desired flexibility without a significant sacrifice of overall strength.
The lengthwise extent of the transverse indentations or undulations provides for a level of shock-absorbing capability because a slight stretching of the paperband can occur when high tensile forces are applied during rapid removal of the band from a turn-up track assembly or in strapping applications such as baling.
As understood in the papermaking art, paper and paperband can be made in a manner to provide greater strength in the longitudinal direction represented by the direction of the paper through the papermaking machine. The present paperband employs board of 8 to 30 points and is stronger in the machine direction lengthwise than cross-machine direction by about 5:1. Preferably, the board is made of several plies formed of cellulose fibers bonded together and is manufactured on a multi-ply board machine.
The paperband in a first embodiment is formed form a length of board by feeding the board through rollers to provide two spaced longitudinal scores or creases along the length of the board. Adhesive is applied to the upper surface between the scores or creases. The board is then folded by a forming die at the creases so that the side edges are folded inwardly and are closely adjacent each other or even in an abutting relationship over the medial line which may be scored longitudinally at the same time as the creases are formed and pressed to fix the adhesive. Then the board is fed through rollers to corrugate the board transversely. The joint between the outside edges—which may be a small gap—provides for the desired bending medially when the paperband is pulled from a track assembly and such bending may be enhanced by a score line therealong. In a second embodiment, the adhesive may be applied to the entire upper surface (see
Construction
With respect now to the drawings, the paperband includes multi-ply board 11 folded to form gap 12. Spaced pair of side grooves or creases 15 and a medial longitudinal line or narrow area of weakness 16 is formed by spaced side portions 13 and parallel medial portions 14 forming gap 12. An interior surface 17 has an interior adhesive coating 19 thereon which holds the paperband together. An exterior surface 18 may have a heat or water-activated adhesive coating 20 if the paperband 10 is used for baling. If PVA is used for sealing the band, then the entire exterior surface 18 is preferably coated with adhesive coating 20 (as shown by dotted line 20A in
Transverse undulations or corrugations 21 are created to provide the desired flexibility and may be a wave-like or “sine wave” or any other form that may be appropriate depending upon the use to be made of the paperband 10. Preferably, the roll 29 (
Preferably, corrugations 21 are created as shown in
In
The performance of paperband 38 is similar to that of paperbands 10, 31 in track pullout by way of flexing at joints 48 and 49. After pressing to fix the adhesive 46, 47, the desired transverse undulations are formed as in the other embodiments previously described. The soft bends 41 and 42 are formed in the manner described to provide the paperband 38 with substantially planar outer surfaces as the ends 50, 51 transition more smoothly with adjacent portions of soft bends 41, 42 to create relatively flat sides for the paperband 38 (
The preferred paperbands 31 and 38 provide for the use of thinner multi-ply board (for the same bulk) than other embodiments. This derives from the higher strength/density of the thinner board. The horizontal and vertical symmetry of the completed band is also preferred. The folded edge portions provide for the “flexing” or bending during turn-up and also provide for high resistance to cross-wise tearing of the band and reduced fiber damage during compression-forming of the band. The thinner board also allows for more footage at the same diameter thus providing for fewer splices of the band.
The undulating or wave-like formations of the paperbands are defined in terms of parameters including height, width and number per unit elongate length and are the result of the use of rollers or any other appropriate apparatus. The creation of the corrugations or undulations 21 causes a selectable shortening of the paperband 10 that provides a shock absorbing capability when tensile force is applied to the paperband 10 when it is stripped out of track assembly 24 during turn-up or when being pulled tightly during a baling operation.
In baling pulp it is common for the bale to “grow” or become enlarged as it absorbs moisture from its surroundings. An additional benefit of the corrugations of the band is that it allows for growing of the bale without considerably affecting the overall strength of the band under the circumstances. The size, shape and number of the corrugations can be varied to adjust the stretchability and/or stiffness of the band as desired in a specific application.
The preferred methodology of forming the paperband 10 is as follows:
A. The score or crease lines 15 are formed.
B. Adhesive is applied to the center portion 14 between the scores 15 (not preferred adhesive applied to side portions 13).
C. The side portions 13 are folded over by a forming die.
D. The side portions 13 are then pressed onto the medial portions 14 to fix the adhesive.
E. Transverse corrugations 21 are formed in the paperband.
The specific type of formations 22, 23 and how they are formed varies in the circumstances. It is important, however, to avoid scores or cuts or similar formations that result in a reduction of the tensile strength of the paperband as such result would be counterproductive. Transverse indentations which do not materially affect the strength of the paperbands in accord with the present invention may be employed to create undulations where dictated by the specific application.
As the undulations are more pronounced by pressure of the rollers, the height of the undulations are increased and/or may be less pronounced by decrease in roller pressure. Alternately, the width of undulations and/or the number per lineal distance may be varied to increase or decrease the stiffness and/or stretchability of the paperband. In addition, the folded edges of the paperbands 10, 31, 38 minimize cross tearing of the paperbands 10, 31, 38. Preferably, all plies are made of cellulose fibers although other material may be used if necessary. Also, all adhesive, which may include PVA, is water-soluble to aid in repulping of the paperband particularly in baling applications. Preferably, if PVA is used, the adhesive is applied to both sides of the paperband because the adhesive sticks best to itself. The use of PVA on only one side results in inadequate adhesion in many circumstances.
While the application has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.
This application is related to an application entitled “ROLL OF PAPERBAND” Ser. No. 10/617,418, filed Jul. 11, 2003; and an application entitled “ROLL OF PAPERBAND” Ser. No. 10/878,727, filed Jun. 28, 2004.