This application claims the priority of German Patent Applications, Serial Nos. 10 2013 217 994.4, filed Sep. 9, 2013, 10 2013 218 955.9, filed Sep. 20, 2013, and 10 2013 223 854.1, filed Nov. 21, 2013, pursuant to 35 U.S.C. 119(a)-(d), the disclosures of which are incorporated herein by reference in its entirety as if fully set forth herein.
The present invention relates to an apparatus and method for fluting corrugated board or solid board.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
To ensure clarity, it is to be understood by persons skilled in the art that fluting as used in the following description applies to any kind of both corrugated board and solid board. In the event, the term “board” is used alone, it relates to both corrugated board and solid board, and even when referring to “corrugated board” only, the same description is applicable to solid board as well.
To produce products from corrugated board or solid boards, slots or flutes are provided in the board. Slots relate hereby to a cutting of narrow indentations in a board, whereas fluting effects a local compression of the board. The flute lines, which typically involve a straight line, form a crease where the board is then bent to form for example a box from the flat board.
For example, when the flute lines should extend in orthogonal relation to the upper edge or lower edge of the blank of corrugated board and bending of various panels of the blank is not realized along the flute line because the flute line is formed inadequately, the blank will not close flush after folding. Rather the upper edge or the lower edge of end panels are disposed offset to one another so that the side edge of the one end panel does not precisely lie on a joint on the other end panel of the blank. As a result, the box of corrugated board is fastened askew. The quality of the box is therefore inferior and thus unacceptable.
It would therefore be desirable and advantageous to provide an improved apparatus and method to obviate prior art shortcomings and to enable a precise and reliable fluting of corrugated board.
According to one aspect of the present invention, an apparatus for fluting corrugated board or solid board includes a first sonotrode, and a member placed in opposition to the first sonotrode and selected from the group consisting of an anvil and a second sonotrode.
Tests have shown that a board can be manipulated lastingly and locally with the aid of an ultrasound device so as to realize a permanent and very distinct flute line. As a result of the attainable superior geometry of the flute line, the blank of corrugated board can be bent or folded very precisely, reliably and repeatedly. Dimensional tolerances and angle tolerances of folded products of cardboard can be significantly reduced.
Especially the variation of the values of the so-called gap tailings and fish tailings, which represent a reference for the dimensional precision of the corrugated board boxes and the bending capability or parallelism of the edges of the corrugated board boxes, is significantly improved. As a result, product quality is consistent and waste is kept to a minimum. Also, upsetting pressure of bent board blanks that have been fluted in accordance with the invention are superior to boxes that have been fluted conventionally.
To ensure clarity, it is necessary to establish the definition of several important terms and expressions that will be used throughout this disclosure. The term “sonotrode” relates to the part of an ultrasonic welding device that subjects a workpiece to vibrations, produced by an ultrasonic generator. The counterpart to the sonotrode is the anvil. The workpiece, here corrugated board, is compressed between the anvil and the sonotrode at a comparably slight contact pressure. Instead of the anvil, the counterpart to the sonotrode may also be a further or second sonotrode disposed in opposition to the first sonotrode. In this way, ultrasonic vibration is applied even more intensely. For convenience and sake of simplicity, the following description relates in particular to the presence of an anvil, even though the principles described in the following description with respect to “anvil” are equally applicable to an embodiment with two sonotrodes disposed in opposition to one another.
Provided between ultrasound and generator and sonotrode(s) may be a converter and/or a so-called booster. The construction of the ultrasonic device may be similar or identical to a conventional ultrasonic welding device.
According to another advantageous feature of the present invention, the first sonotrode and/or the anvil can be mounted for rotation about a rotation axis. This ensures the formation of straight flute lines in a rapid and reliable manner. The board can be moved through the apparatus or the apparatus can be moved in relation to the board, when the board is stationary.
According to another advantageous feature of the present invention, the first sonotrode and/or the anvil can be rotatably driven.
According to another advantageous feature of the present invention, the first sonotrode may be stationary and have a straight or curved edge of a shape and dimension in correspondence to the desired flute line. This configuration is especially beneficial when flat bed die-cutting of corrugated board blanks is involved.
According to another advantageous feature of the present invention, a feed device can be provided to advance either the sonotrode, anvil, the second sonotrode and/or the corrugated board. The corrugated board may hereby be guided through a gap between the first sonotrode and the anvil or second sonotrode, while the first sonotrode is stationary. Advantageously, the first sonotrode or the anvil may have a wedge-shaped insertion incline at an entry side of the apparatus.
According to another advantageous feature of the present invention, the first sonotrode and the anvil can be spaced from one another by an adjustable distance. Also, a contact pressure between the first sonotrode and the anvil can be adjustable. As a result, the apparatus can be used to process various corrugated boards, for example with one corrugation, two corrugations, or three corrugations, or a solid board in an optimum manner.
According to another advantageous feature of the present invention, a spray device can be provided to locally moisten the corrugated board in the region of the later flute line. Advantageously, the spray device is configured to moisten the board on the side that faces the first sonotrode. This improves application of the ultrasound into the board. It has also been shown as beneficial in some applications to moisten the sonotrode-distal side of the board because in this way, welding is improved to implement the connection or shaping of the various layers of the corrugated board and because of the presence of tensile forces in this region when later the board blanks are bent or folded over. When moistening the board in this region, the risk of tearing of the board is reduced when being bent.
According to another aspect of the present invention, a method includes the steps of compressing a local zone of a solid board or layers of a corrugated board between a first sonotrode and a member selected from the group consisting of an anvil and a second sonotrode, and subjecting the local zone to ultrasound.
According to another advantageous feature of the present invention, the compressing and subjecting steps can be carried out at a same time. Advantageously, the compressing and subjecting steps can be carried out with same tools.
According to still another aspect of the present invention, a computer program embodied in a non-transitory computer readable medium, wherein the computer program, when loaded into the processing device and executed by the processing device, causes the processing device to perform the steps of compressing a local zone of a solid board or layers of a corrugated board between a first sonotrode and a member selected from the group consisting of an anvil and a second sonotrode; and subjecting the local zone to ultrasound.
According to still another aspect of the present invention, a control device for an apparatus for fluting corrugated board is constructed to execute perform the steps of compressing a local zone of a solid board or layers of a corrugated board between a first sonotrode and a member selected from the group consisting of an anvil and a second sonotrode; and subjecting the local zone to ultrasound.
Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
Throughout all the figures, same or corresponding elements may generally be indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the figures are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.
Turning now to the drawing, and in particular to
In the exemplified illustrations of
In the non-limiting example of
When considering the exemplary embodiments of
Precision and process reliability of the apparatus according to the invention or the flute line 13 produced by a method according to the invention is much improved compared to conventional mechanical flutes in corrugated board or solid board and thus enables a precise manufacture of products from board with slight dimensional and angle deviations.
In this exemplary embodiment, the sonotrode 25 and the anvil 27 are rotatably mounted. The flute line 13 is established by the interaction of sonotrode 25 and anvil 27. The invention may also be realized when the sonotrode 25 and the anvil 27 are not rotatably supported by stationary.
While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit and scope of the present invention. The embodiments were chosen and described in order to explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein:
Number | Date | Country | Kind |
---|---|---|---|
10 2013 217 994.4 | Sep 2013 | DE | national |
10 2013 218 955.9 | Sep 2013 | DE | national |
10 2013 223 854.1 | Nov 2013 | DE | national |