EP1022123B1 - Process and device for production of cushioning material and the cushioning material so produced - Google Patents

Abstract

The method is carried out in steps: The flat material is partly cut through in such a manner, that transversely lying adjacent strip sections in the region of connecting sections spaced at a distance to each other longitudinally, remain connected with each other. The strip sections (65,66) are deformed between connecting sections (67) at right angles to a neutral surface of the flat material in such a way. The strip sections adjacent transversely (69), are deflected in opposing directions.

Description

The invention relates to a method and a device for Production of upholstery material, in particular for packaging purposes, and a corresponding padding material.

Padding material and methods and devices for its preparation are known from US-A-5,667,871 and US-A-5,439,730.

In many areas of goods traffic, for example in Production plants, retailers or end consumers often accumulate in large numbers of packaging, which after Removing the goods are usually disposed of unused. packagings made of inherently rigid flat material, such as cardboard, corrugated cardboard, Cardboard o. The like. Are this mostly torn or on other way dismembered and collected the waste paper cycle fed. A proper disposal is not with associated with negligible work and expense.

Another problem in the packaging sector arises in Upholstery materials used in the packaging of against mechanical Actions sensitive products are used around these products e.g. during transport against shocks and to protect similar actions. Often become this Plastic chips used as padding material, both in production as well as disposal costs and in particular if not disposed of properly pose a burden on the environment.

The invention is based on the object improvements in To suggest the area of packaging.

This object is achieved by a method with the features of claim 1, a device having the features of Claim 4 and a padding material having the features of Claim 11.

According to the method of the invention is a particular padding material suitable for packaging purposes of inherently rigid Flat material such as cardboard, cardboard or the like in such a way that the sheet partially into strip portions is severed that in the transverse direction of the strip adjacent strip portions in the region of in the longitudinal direction the strip with spaced connection areas stay connected and by the Strip portions in a direction transverse to a neutral surface of the flat material between the connecting areas be deformed so that adjacent in the transverse direction Strip sections deflected in opposite directions become.

The inventive deformation of the sheet can with respect to the starting flat material possibly a disposal problem and by the resulting cushioning material a manufacturing problem be solved. An intrinsically disturbing, because superfluous starting material, such as a packaging cardboard packaging, is not disposed of costly, but immediately for a new use in an appropriate manner transformed. From the essentially two-dimensional Flat material, for example, a thickness between about 0.5 mm and about 5 mm and can be perpendicular to the surface extent usually only slightly zusammenpreßbar is by the forming according to the invention a cushioning material with created a substantially three-dimensional structure, now that by the envelope surface of the deformed Material "thickness" of the material a multiple of the material Output thickness can be and a shock-absorbing compliance in the area of the deflected strip sections is created. Furthermore, by dividing into Longitudinal strips the cushioning material in the transverse direction well flexible, so that, for example, for the packaging of Bring bottles to the bottle contour. Also in the longitudinal direction is a bending and / or compression of the Structure made up of contiguous strips. The cushioning effect is substantially in the range of generated in opposite directions deflected strip sections, which after Separation and deformation substantially permanently deflected are frictionally engaged in shape by edge friction being held. An improved conservation of the deflection can be achieved by cutting the edges slightly frayed or finely toothed. Therefor are appropriately processed cutting discs of Contraption.

Although it is possible to have several adjacent strips as Group in one direction and a subsequent group or to deflect a single strip in the opposite direction, are preferred single strip sections alternately deflected in opposite directions, resulting in a particularly good cushioning effect.

The open, three-dimensional padding material structure can For example, be generated by a stamping process at the forming substantially simultaneously over a larger, in particular the entire surface of the starting material he follows. A separation by strip cut is preferred with a plane parallel to the neutral surface of the sheet extending cutting direction, wherein for generating the Connecting sections of the strip section sections is interrupted. This is the transformation of the starting material in a continuously progressive process energy saving possible and it can also be used to generate larger-area upholstery material parts relatively small, space-saving deployable cutting devices are used. to Upholstery material production may be suitably modified, for Strip cut designed document shredder o. The like. be used.

A particularly advantageous material structure can at a Training be generated by groups of example three transversely adjacent connecting regions each separated in the transverse direction. This allows the flexibility of the cushioning material in Longitudinal direction, ie with a curvature about a transverse direction parallel Axis, to be improved because in the separation area a mutual movement of each at the connection areas held together groups of strips becomes. In addition, a reversible elasticity of the material in Transverse direction created.

The padding material made possible by the invention can exclusively from the intrinsically rigid starting flat material exist because in the padding material production neither new Substances such as adhesives or the like, added at temperatures or environmental conditions must be worked in which could possibly result in adverse changes. Suitable starting materials are in particular packaging materials such as rigid paper, fine board, cardboard or corrugated board, wherein the materials are each single-layered or multi-layered could be. Typical starting thicknesses are between about 0.5 and about 5 mm, but may be larger in exceptional cases or be smaller. Typical thicknesses of the produced padding material can be between about double and five times the starting material thickness and / or between approx. 1 mm and approx. 25 to 30 mm. Particularly suitable strip widths of normally limited essentially parallel side Strip sections can be between about 0.5 and 4 times the Thickness of the sheet are, in particular between 1 and 2 times this initial thickness. Such relatively compact Cross sections are particularly formhaltig and damping.

The mean strip length between successive ones Connection areas can be more than 5 times, preferably between 20 times and 40 times the thickness of the Flat material and / or between about 3 and about 20 times, especially between about 10 and about 15 times as big as the stripe width. This is a good compromise between the achievable by the free strip length achievable Cushioning material thickness and the damping effect achievable. It should be noted that experience shows that Padding becomes smaller with increasing strip length.

Due to the possible use of the invention in the essential two-dimensional, intrinsically stiff flat material or packaging material for the production of substantially Three-dimensional, shock-absorbing padding material will not only the disposal problem regarding no longer usable Packaging carton o. The like. Solved, but it will be created inexpensively producible padding material, the if necessary, be used several times and, if one more Use is not required or desired, environmentally friendly into the disposal circuits already established for packaging materials can be returned. Of course can also be used as a starting material flat material that has not been used before.

One in particular for carrying out the method described suitable device for producing padding material is based on the principle of the known, also known as Shredder designated document shredder. she has a Cutting unit with two cooperating, counter-drivable Cutting rollers, each of which has a plurality of Cutting discs has axially bounded by cutting edges are and between which axial spaces are provided, in each of the cutting discs of the other cutting roller in an overlap area up to a maximum Intersection depth for generating a cutting engagement intervention. In devices according to the invention are the Cutting rollers formed such that the cutting engagement between adjacent cutting discs during one revolution interrupted at least once. This will be during of a normally overwhelming portion of the round Strip cut in the manner of the known strip cutter document shredders generated, but during the Interruption of the cutting engagement of a connecting bridge remains between directly adjacent strips. The deformation adjacent strip sections in opposite Direction is achieved without further steps that the strips of flat material from the cutting discs respectively in the opposite spaces or punctures the each other cutting roller pressed.

Particularly advantageous is a development in which Cutting discs preferably circular peripheral surfaces have, by at least one circumferential groove or edge recess are interrupted, wherein the groove has a groove depth, the is equal to or greater than the maximum overlap depth cooperating cutting discs. This causes it outside of the groove area in the region of the cutting gap to a Overlap and thus to a separation of neighboring Material areas, while in the non-overlapping peripheral section no cutting action takes place in the region of the groove and accordingly one of the strip sections in the transverse direction connecting bridge remains. Their longitudinal extent is in essentially determined by the circumferential length of the groove area, equal to or lower than the depth of intersection is. This circumferential length may e.g. between about 2% and about 5 % of the cutting wheel circumference length. In a preferred Further development, the cutting discs have two diametrically opposed grooves, being generally preferred is when a cutting disc is a preferably even number of regularly distributed around the circumference of the cutting disc Has grooves, for example two, four, six or eight such Grooves.

In a further development it is provided that the cutting rollers are arranged to each other such that in an overlapping area of cutting discs at least in some Cutting discs next to a groove of a cutting disc of a cutting roller a groove of a cutting disc of the other Cutting roller is located. As a result, upon rotation of the cutting rollers at some axial sections of the cutting rollers, the grooves offset opposite cutting rollers to each other. hereby becomes one for a uniform padding behavior the cushioning material particularly preferred deformation in the substantially symmetrical to the starting material surface achievable. In addition, intersecting grooves a cutting engagement avoided even if each groove flatter for itself as the maxiamle overlap depth is, as long as only the Sum of groove depths greater than the maximum intersection depth is, so that in the cutting gap a clear distance between the groove grounds or groove floors remains.

It is particularly advantageous if grooves adjacent Cutting discs of a cutting roller in the circumferential direction an even fraction of 180 ° offset from each other are, for example, at 45, 60 or 90 °. By this offset the grooves can be achieved that the connection areas individual strips or groups of strips in the longitudinal direction Seen alternately transversely offset against each other. Thereby is the cut cushioning material in longitudinal and in Transverse direction very flexible and reversible in transverse direction stretchable.

To avoid an unwanted cross-section or Cross-section at the strip sections in the area of the groove edges is provided in a development that in the transition area between a groove and the peripheral surface of the cutting disc a bevel and / or a rounding provided is.

For the convenience of operation in the supply of material and the removal of the cushioning material is at a preferred Embodiment provided that the cutting discs one above the other or substantially vertically one above the other are arranged, whereby a material supply of the usually flat flat material and a discharge of the produced Padding material in the horizontal direction is possible. at horizontal material throughput is e.g. especially easy, the material outlet a suitable collection and / or transport device o. the like nachzuschalten.

A preferably for operating the device described suitable method for the drive electric motor for the Cutting mechanism of the device is characterized in that from a direct current, in particular of any origin, by forming an at least single-phase alternating current is generated, fed with the drive electric motor becomes.

Devices for construction-type shredders for document destruction often have so-called universal motors, their special design operation also with AC voltage allowed. Usually they are used in applications such as Office area with the usual building AC voltage (230 volts, single phase) operated. Construction-related disadvantages of universal motors such as wear and radio interference problems are partly due to the use of three-phase asynchronous motors, for example, squirrel cage motors, avoided. For this purpose, however, are separate three-phase connections to install, especially in the office area in many Cases associated with high costs.

Other solutions provide the rotating field by means of a phase-shifted Generate magnetic field. The required Phase shift is achieved by connecting a capacitor achieved in order to operate a single-phase motor. there However, because of the performance characteristics of such drives the large current heat losses in the rotor and the large no-load current not very well. The performance corresponds to about 65% of the power of a comparable three-phase motor.

By the invention of the method for the drive electric motor With the features of claim 16, a method be created, with the disadvantages of the state of the Technology can be avoided with which a drive electric motor can be operated with higher power, this in particular to a plurality of supply connections should be connectable.

Starting from the direct current, this allows a wide Design latitude for generating the at least single-phase Alternating current. Preference is given to three-phase alternating current generated, so three-phase current. The direct current can be in one AC variable frequency be converted. This allows adaptation to any required Operating state of the electric motor. Preferably is at low load of the electric motor in operation a high Frequency adjusted, which is mainly in use of squirrel cage motors a higher speed and thus results in faster destruction of documents. It can be provided several fixed speeds, with which different speeds (slow, medium, fast) for different modes of operation can be set. The gear ratios for the cutting unit can be different be selected, especially for high torque at normal Rotation speed. By increasing the frequency is then a higher Speed possible. Further advantages, especially during startup of the electric motor, can through a continuous change the frequency and thus the speed can be achieved. The wear of the entire device can be reduced by eliminating sudden peak loads or jerky speed changes. It will continue the operating comfort increased.

Special advantages of this method for devices for Production of cushioning material is, inter alia, that thus also professional, powerful and robust Three-phase motors for office applications without three-phase connection become available. Advantages of three-phase motors are also in the lower noise, which in turn benefits for the office area brings. In particular, a very good Controllability of the three-phase machine achieved by change the frequency of the output AC current at the inverter. Thus, thin cardboard material can be very fast, thick or very thick with low speed and very high Torque be edited. This allows it to be different thick starting materials needed each Make padding material according to individual requirements, a provision of a supply of finished cushioning material its unneccessary. The starting material in turn is very much more space saving than the padding material. By the Invention, it is possible for the first time, these advantages with a To achieve office-friendly device.

In addition, the amplitude of the alternating voltage can be variable be to adapt to the demanded by a user Operating behavior of the electric motor. Preferably, the generated AC sinusoidal, with the power electronics the converter also other, in particular any Shapes or waveforms can be generated.

On the one hand, it is possible to get the direct current out of one installed DC network, possibly from an emergency power supply or an accumulator, to obtain. Preferably, the DC is from any AC supply generated, in particular a single-phase AC power supply. In this way, for example via the DC link from a normal 230 Voltage terminal a desired, for example, three-phase, AC are generated. With such a method may be a device for producing padding material with a three-phase motor operated on a standard socket become. Further advantages that result from a reshaping of a AC via a DC link in one Supply alternating current for the electric motor are, are within wide limits arbitrary adjustability of frequency, Amplitude and shape of the generated alternating current. detailed Explanations can be found below in the Figures.

A possible method according to the invention may provide that the alternating current for the electric motor through an inverter generated as the first inverter from the direct current is, wherein the inverter preferably via a DC link with a rectifier as second inverter connected to generate the direct current from the mains voltage is. The converters are preferably power electronics modules, for example with TRIACS, power transistors or thyristors equipped as valves. On the one hand, the Inverter be connected to each other via a kind of buffer, On the other hand, it may be possible to associate them directly with each other couple, possibly via a DC link. Of the Inverter depends on the alternating current to be generated trained, usually with six valves to Generation of three-phase current.

One in particular for carrying out the method of operation the drive electric motor suitable means has at least one converter, which consists of a direct current an alternating current with at least one phase for the Electric motor generated. The inverter works as an inverter and preferably generates three-phase current. Advantageously, a Three-phase motor or an asynchronous motor can be used. In particular, an asynchronous motor with a squirrel-cage rotor for operation on a three-phase alternating current of Advantage. Through a converter with power electronics can generates an alternating current of substantially any shape become. In addition to the aforementioned inverter as the first Inverter can be a rectifier as second inverter be provided by which it is possible to use the direct current to produce from an AC supply. This can For example, be single-phase, for example, as usual in Home or office area installed outlet. The second Inverter can be implemented in a variety of ways DC link to be connected to the first inverter. A Frequency adjustment of the first inverter for speed change the engine can be adjusted by hand, for example, at least three to a maximum of ten times Exaggeration of the frequency.

Furthermore, it is possible to drive on the electric motor To arrange speed sensor, in particular on one of his Shaft ends for controlling at least one of the inverters in Depending on the load case and / or the position of the shaft of the Engine. A load detection can be performed by a speed sensor, a current detection or other suitable sensors respectively. Advantageously, the first inverter with it modulated.

These and other features are excluded from the claims also from the description and the drawings, wherein the individual features in each case alone or to several in the form of subcombinations in one embodiment of the invention and realized in other fields and can represent advantageous embodiments for which protection is claimed here.

Fig. 1

eine schrägperspektivische Gesamtansicht einer Ausführungsform einer erfindungsgemäßen Vorrichtung zur Herstellung von Polstermaterial,

Fig. 2

einen vertikalen Längsschnitt durch die Vorrichtung gemäß Fig. 1,

Fig. 3

einen vertikalen Querschnitt durch die Vorrichtung gemäß Fig. 1 im Bereich ihres Schneidwerks,

Fig. 4

eine perspektivische Ansicht eines axialen Ausschnitts einer Schneidwalze des Schneidwerks,

Fig. 5

einen Ausschnitt aus einer Schneidscheibe einer anderen Ausführungsform im Bereich einer Umfangsnut,

Fig. 6

eine horizontale Draufsicht auf einen axialen Abschnitt einer Ausführungsform eines Schneidwerks,

Fig. 7

einen Detailschnitt durch das Schneidwerk gemäß Fig. 6 beim Durchtrennen von Flachmaterial,

Fig. 8

eine schrägperspektivische Ansicht eines Ausschnitts von Polstermaterial, das mit der Vorrichtung gemäß Figuren 1 bis 7 herstellbar ist,

Fig. 9

eine schematische Darstellung eines Gleich- und eines Wechselrichters, die einen Antriebs-Elektromotor für die Vorrichtung gemäß Fig. 2 speisen,

Fig. 10

eine Kennlinie eines Drehstrommotors im Vergleich zu der eines Kondensatormotors und

Fig. 11

ein Betriebskennlinienfeld für einen erfindungsgemäß versorgten Drehstrommotor.

An embodiment of the invention is illustrated in the drawings and will be explained in more detail below. In the drawings show:

Fig. 1

a perspective view of an overall perspective view of an embodiment of a device according to the invention for the production of cushioning material,

Fig. 2

a vertical longitudinal section through the device of FIG. 1,

Fig. 3

a vertical cross section through the device according to FIG. 1 in the region of its cutting unit,

Fig. 4

a perspective view of an axial section of a cutting roller of the cutting unit,

Fig. 5

a detail of a cutting disc of another embodiment in the region of a circumferential groove,

Fig. 6

a horizontal plan view of an axial section of an embodiment of a cutting unit,

Fig. 7

a detail section through the cutting unit of FIG. 6 during the cutting of flat material,

Fig. 8

a perspective view oblique view of a section of cushioning material that can be produced with the device according to Figures 1 to 7,

Fig. 9

a schematic representation of a DC and an inverter, which feed a drive electric motor for the apparatus of FIG. 2,

Fig. 10

a characteristic of a three-phase motor compared to that of a capacitor motor and

Fig. 11

an operating characteristic field for a three-phase motor supplied according to the invention.

Figures 1 to 3 show a device 1 for the production of shock-absorbing padding material from packaging cardboard or other suitable, inherently rigid sheet. The Device has a lockable, steerable rollers mounted housing with a box-shaped housing lower part 2 with largely flat top 3 and one with a Distance of a few centimeters above the lower part of the housing horizontally arranged, flat housing upper part 4, at the Front controls are arranged for the machine.

An integrated cutting device 20 for the flat material comprises a mounted on the top 3, longitudinal Stop bar 21 and one with a transverse distance of about 40 cm to the stop bar arranged, vertical Cutting knife 22 that one on the cutting blade side open, horizontal gap 23 between lower part top side. 3 and housing upper part 4 bridged and also as a support for the upper housing part is used. The cutting device 20 makes it possible, if necessary, large pieces of flat material Strip with one of the working width of the cutting unit Width to cut or cut.

In the housing base is just below its top 3 approximately in the middle between front wall and rear wall Cutting unit 5 arranged, the one about a horizontal axis 6 rotatably mounted upper cutting roller 7 and vertically underneath one about an axis 6 parallel axis 8 rotatable lower cutting roller 9 has. The superimposed Cutting rollers are from one below the cutting unit the housing front wall mounted electric motor 10 via a Synchronization toothed gear 11 driven in opposite directions rotating.

Each by turning (grooving) of metallic solid material manufactured cutting rollers (Fig. 6) has a continuous Cutting shaft 12 and projecting therefrom at regular intervals Cutting discs 13, between which ringnutförmige Gaps 14 are formed. Per cutting roller are about 50 Cutting discs with a diameter of approx. 78 mm and a width of about 4 mm, which is a total working width of Cutting unit of about 43 cm results. Each of the cutting discs has an interrupted in the range of later explained grooves, substantially cylindrical radial peripheral surface 15 and is axially limited by the interstices, essentially level and perpendicular to the shaft axes Cutting edges 16 limited.

In the embodiment of a cutting roller shown in Fig. 5 is the peripheral surface by a central, in the circumferential direction extending V-groove 17 divided and the to the Side edges adjacent peripheral surface strips are through an axial knurling 18 roughened. The surface roughening, which also brought about by ball or sand radiation is used to improve the intake behavior of the cutting unit. The cutting discs can also as individual washers are made, the intermediate layer of the spacers o. The like. On a shaft rotatably lined up. The vertical distance of the cutting roller axes 6, 8 is sized so that the cutting discs each up to a maximum depth of engagement or overlap 49 engage each other and alternately one Cutting disc of a cutting roller in the gap or the Space between two cutting discs of the opposite Roller engages. It remains between cutting disc peripheral surface and by the cutting shaft of the opposite bottom of a formed cutting roll Space between a clear distance, about the depth of engagement 44 corresponds and / or between approx. 5% and 20% of the Cutting disc diameter can be. In order between the Cutting discs to make a cutting engagement are the Interspaces 14 each only by tenths of a millimeter wider than the engaging cutting discs. The intervention or Intersection area 19 of the cutting discs is also called Cutting gap of the cutting called.

In the example shown, the to be cut and in Pad material to be reformed by means of a Material guide 25 in horizontal direction to the cutting unit guided and discharged after separation in a horizontal direction. This is approximately at the height of the cutting gap in the housing base 4 a few inches high and about 40 cm wide material guide channel 26 is provided, the before and behind the cutting unit through mutually parallel, even horizontal boundary surfaces 27, 28 is limited and itself both inlet side and outlet side in the range of Sloping surfaces extended to allow material introduction or material removal to facilitate.

The cutting rollers are located on both sides of the material guide channel in downwardly or upwardly opened rectangular recesses 29, 30, at the height of the boundary surfaces 27, 28 inserted through Guiding plates 31, 32 of a stripping device 33 bridged are. The rectangular U-shaped angled baffles are inserted between the two cutting rollers and run between the edges of the recesses 29, 30 horizontally in extension of the boundary surfaces 27, 28 and tangential to the cutting shafts near the well-near bottoms of the interstices 14. They have rectangular in the field of cutting discs Slots through which the cutting discs with small side clearance, but without edge contact in the Projecting portion of the material guide channel 26. The Baffles are used to strip the finished Padding material from the cutting rollers and prevent one Transport of clippings through the rollers in the area of Recesses. They are single compared to conventional ones inserted individual scrapers with comparable stripping effect significantly less expensive to produce, since they, for example stamped in one piece from a sheet metal part and used to form the Rectangular angle shape can be bent.

The cutter 5 is similar to a cutter known Document shredder designed for strip cut, wherein However, due to a special geometry of the cutting rollers in the Area of the cutting discs no through, but in Lengthwise sectionally interrupted cuts produced become. As a result, the treated sheet is in one another split contiguous strip sections, wherein to achieve sufficient padding, the strip sections each alternately in the opposite direction are deflected or deformed. This can be done by the in Fig. 4 achieved example shown geometry of the cutting discs become. The cutting discs of the local cutting roller 40 are each identically shaped, but are axially adjacent Cutting discs rotated by 90 ° to each other. The front cutting disk 41 has two at its periphery grooves 43, 44 arranged diametrically to the cutting shaft axis 42; the circular-cylindrical represented for reasons of simplification, usually by a knurling or a other roughening structured outer peripheral surface in Interrupt circumferential direction.

The grooves each have a largely flat, vertical to the shaft radius aligned groove bottom 45, which is about extends a circumferential angle of, for example, about 10 to 15 ° and by parallel to each other and perpendicular to Groove running edge portions 46 in the circumferential direction is limited. These go about halfway up in about 45 ° inclined to the radial direction inclined surfaces 47 via. These Oblique flattening, which also by a transition radius can be replaced, breaking the groove edges and serves the Avoidance of unwanted cross-section when overlapping adjacent cutting discs in the groove area.

The groove depth 48, the radial distance between the groove bottom 45 and the imaginary arcuate extension of the radial Peripheral surface in the central region of the groove corresponds, is in the embodiment shown so to the center distance of the Adapted cutting shafts and the diameter of the cutting discs, that it is greater than the maximum overlap 49 the cutting blades in cutting engagement. This overlap 49 (FIG. 6) is calculated as Difference between the sum of the maximum cutting wheel radii co-operating cutting rollers and the center distance the cutting rollers. The cutting disc 41 adjacent Cutting disc 50 is opposite to this 90 ° about the axis 42nd twisted while the subsequent cutting disc 51 again with the front cutting disc 41 is aligned and the rear Cutting disc 52 with the second cutting disc 50 u.s.w.

The axial sequence of staggered cutting discs is also clearly visible in Fig. 6. This illustration shows an axial section of the cutting mechanism in the material feed direction considered, wherein the cutting rollers against the Representation in Fig. 4 rotated by, for example, about 30 ° are, so that the grooves are recognizable in oblique insight. At a short time before entering the overlap area standing groove 44 of the disc 41 are for clarity the Nutbegrenzenden surfaces with the reference numerals indicated in Fig. 4 characterized. It can be seen that at further opposite rotation of the cutting rollers, the grooves themselves offset opposite cutting discs each at the same time enter or come into the cutting gap 19 (see Fig. 7). This results in the axial direction a repetitive sequence of different intervention conditions between each cooperating cutting discs. in the Intersection area I meet groove-free peripheral sections the cooperating cutting discs on each other while in the Overlapping area II a groove-free section of the upper Cutting disc on a groove 53 of the lower cutting disc meets. In region III, the groove 53 meets a groove 54 an upper cutting disc, said groove in the area IV on a groove-free portion of a lower cutting disc meets. Finally, in section V, there are two more groove-free peripheral portions of cutting discs on each other. After further rotation of the cutting rollers by 90 °, this occurs Order of engagement in the axial direction of the cutting rollers to two cutting disc widths offset so that then e.g. in the Area III is a continuous cut. This periodicity with a periodicity length of four cutting wheel widths suggests itself in the training of the one shown in Fig. 8 Padding down.

With reference to Fig. 7 will now be feasible with this device Process for the production of cushioning material explains, by way of example, the case is shown that with opposite rotation of the cutting rollers in by the Arrows 55 indicated directions a circumferential groove 56 of the Viewer facing upper cutting disc 57 in the cutting gap on a groove 58 of a rear lower cutting disc 59 hits.

The flat material 60, for example a single-ply corrugated board, enters the overlap area in the horizontal feed direction 61 the cutting discs and is everywhere where the cutting edges of cooperating cutting discs If necessary, overlap rubbing, severed by shearing, where in each case the width of the resulting strip sections essentially the width of the cutting discs equivalent. This starts the cutting separation of the Materials each time the material enters the general lenticular overlap area (between the points 62 and 63 in Fig. 7) and continues to progress Rotation of the cutting rollers while drawing material into the Cutting gap, as long cutting edges axially each other are opposite. The material is on both sides of the Cut of the respective adjacent cutting discs in the each of the cutting disc associated, opposite Space pressed in, resulting in a deformation of adjacent Strip sections in opposite directions relative to the normally planar neutral surface 64 of the sheet leads.

In the example, the strip section facing the viewer becomes 65 through the upper cutting disc 57 and their cylindrical circumference pressed down, while the rear Strip section 66 through the lower cutting disc 59 after is pressed up. The progressing in the longitudinal direction Strip cut is interrupted as soon as the cutting engagement is canceled between cooperating cutting discs. This is the case in the example shown where the grooves 56, 58 meet. The in this area located Flat material remains largely intact and uncut and forms a connection region 67 in the transverse direction adjacent strip sections connects and holds together. It it is obvious that the length of the interruption of the Longitudinal section of the circumferential extent of the groove portion which is lower than the maximum intersection depth is. Due to the length of the connecting sections is also the Stiffness of the resulting cushioning material in the longitudinal direction influenced. It is further evident that the length each between the connection areas of each other separate strip portions of the circumferential spacing of successive Grooves depends. These dimensions can be adjusted accordingly the flat material used and the desired Cushioning effect by appropriate design of shaft diameter, Cutting disc width and number of grooves in wide Limits are varied.

The one-ply corrugated board 60 shown in FIG. 8 padding material produced the described device consists of longitudinally 68 parallel to each other Strip portions 65, 66 whose width in the transverse direction 69 is determined by the width of the cutting discs and in the example about 4 mm. In the transverse direction 69 adjacent Strip sections hang in the region of longitudinally spaced connecting portions 67 with each other together, with the length of the connection areas substantially is determined by the groove widths of the cutter discs and may be for example about 6 to 8 mm. By the in the Related to Fig. 7 described interlocking or deformation of adjacent strip portion opposite Directions are the stripes in the transverse direction seen alternately bent in the opposite direction, the bend being partly due to frictional contraction the bent strip sections near the connection areas is maintained. Because of Clarity is only the four facing the viewer Strip shown in its deformation state.

Based on the explained in connection with Figures 4 and 6 Offset of the circumferential grooves are the connection areas or Interruptions between strips in alternation offset against each other. In the middle approximately across the shown region extending connecting zone 70 is the front strip section 65 with the next strip section 66 connected. Also to the subsequent strip section 71 and the adjacent strip 72 consists a connection zone about the same width. Between stripes 72 and the neighboring strip 73, however, runs in the longitudinal direction extending section across the connection zone 70, through the connected group of four neighboring ones Strip 65, 66, 71, 72 in this area from the adjacent one Group of four in the same way continuous stripes is disconnected. The separation causes these groups of stripes if necessary in opposite directions based on can bend the sheet surface. These four stripes Comprehensive periodicity is related to 6 explained sequence of cutting operations I, II, III, IV and V, wherein the connecting zone 70 passing through Longitudinal cuts in the area of the cutting interventions I and V are generated.

In the longitudinally subsequent connection zone 74 are the dividing the connection zone in the longitudinal direction Longitudinal sections transversely offset by two strip widths, so that e.g. between the strips 66 and 71 a continuous cut lies. These by the offset of the Grooves brought about, alternately offset connection or Separation of adjacent stripes causes the cut cushioning material in the longitudinal and in the transverse direction is well flexible, with the flexibility around the longitudinal axis however, it is bigger. In the transverse direction results in an elastic Extensibility, so that the material without tearing e.g. be pulled apart to twice its width can. In this case, an expanded metal-like structure of the exploded cushioning material, wherein the connecting portions make an angle to the direction of elongation.

Fig. 9 shows a possible arrangement with an inverter 112 as the first inverter, by a direct current is fed and three-phase AC or three-phase any frequency, shape and amplitude generated. On the DC link 113 is the inverter 112 of the rectifier 114 is fed, which consists of single-phase AC makes a DC. He is one AC connection 115 connected, for example, on a standard single-phase power outlet in an office room.

The inverter 112 is via a three-phase connection line 117 with a three-phase motor 118 as a drive electric motor (corresponds to the motor 10 of Figure 2) connected. Of the Three-phase motor 118 has, in particular at a shaft end 119, a speed sensor 120, the speed and / or position of the rotor of the motor 118 detected. The data is about a Feedback 121 returned to the inverter 112. she can be used to control the supply of the three-phase motor 118th be used. The motor 118 drives according to FIG. 2 Cutting unit 5, which the from the engine via the transmission 11th driven, interengaging cutting rollers 7 and 9 having.

Possibly. can in the DC intermediate circuit 113 is a so-called Be included boost converter, which increases the voltage. This allows a supply of the inverter 112 with a possibly much higher than that at the AC connection 115 lying tension.

FIG. 10 shows in dashed lines a characteristic curve 123 of a Condenser motor compared to a characteristic 125 of a Three-phase motor. The torque M is plotted above the Speed n, which is correlated with the operating frequency. As can be seen, is at the characteristic 125 of the three-phase motor the starting torque higher than the characteristic 123 of the Condenser motor, as well as the overturning moment, that's the area of the maximum moment M. Moreover, the pronounced missing Saddle area of the characteristic 123, which is lower in the area Speeds to the starting torque follows.

Fig. 11 is a diagram showing an operation map. For this purpose, the torque M is plotted against the ratio of the operating frequency f to the nominal frequency f _N. This results in laterally shifted characteristic curves, similar to the characteristic curve 125 from FIG. 2. Their maxima, ie the tilting moments, form an envelope shown in dot-dash lines, which initially runs horizontally and then drops approximately parabolically.

Similarly, the power P of the engine is plotted over f / f _N , but dotted. One point to note is that at f / f _N equals 1. At a nominal frequency f _N of 50 Hz, the corner frequency f _{eck is} also 50 Hz, so the ratio of the two to each other is 1. The power curve starts as the original straight line at zero and runs off f / f _{N is} equal to 1 as a constant. This means that up to the corner frequency f _eck at f / f _N the power of the motor increases and remains approximately the same from the corner frequency. Voltage and output power are proportional to each other in the squirrel cage motor. In an embodiment of the invention, the nominal frequency can be selected greater than 50 Hz, for example, 120 Hz.

Entered are two operating points of the three-phase motor on different characteristics. The first operating point 127 with M1 has almost maximum torque at f / f _N less than 1. This first operating point 127 is taken by setting the frequency f less than f _N across the inverter 112 to handle large quantities of cardboard or thick grades in a cushioning device. Although the cutting speed drops, but almost the maximum torque is applied. By increasing the voltage under f _N , an increase in torque is possible.

The second operating point 129 was chosen to be significantly greater than f _N at a frequency. Although the achieved torque M _{2 is} significantly lower than that of the first operating point 127, but the frequency f and consequently also the cutting speed is about twice as large. This second operating point 129 is preferably chosen to handle thinner padding material to be produced. The dot-dashed curve 128 is the curve on which all operating points lie.

In the range up to f equal to f _N , the motor is driven with constant magnetic flux. The tilting moment remains constant. When the voltage reaches its maximum value, only the frequency is increased further. The magnetic flux and thus the available moment decrease by weakening the field. As a result, the tilting moment decreases quadratically at a substantially constant power. Furthermore, by appropriate choice of the voltage regulation characteristic (variation of the corner frequency), the output engine torque can be increased and thus the engine performance can be optimized.

Registers the motor during initial operation in the field weakening area a low load or amount of starting material, so he will continue to operate in this area. To is a monitoring of the current advantageous. Will against it fed stronger source material, controls the inverter 112 the frequency back to corner frequency. Becomes moreover, more or more starting material supplied, the inverter regulates the frequency as well alternatively the tension back to the maximum torque of the To drive the engine. Achieve frequency and / or voltage a lower threshold or the motor current an upper Threshold, the motor 118 is turned off.

A device according to the invention can be used in a device for producing cushioning material, the inverter 112 and the rectifier 114 and a DC link 113 included. This way can be a compact as well uncomplicated to be connected device. This is then only a normal single-phase power outlet by plugging in.

Claims (11)

1. Method for the manufacture of padding material from an inherently rigid flat material involving the following steps:

   partial separation of the flat material into strip portions in such a way that transversely adjacent strip portions remain interconnected in the vicinity of longitudinally spaced connecting areas,

   deformation of strip portions between connecting areas in a direction at right angles to a neutral surface of the flat material in such a way that transversely adjacent strip portions are deflected in opposite directions.
2. Method according to claim 1, characterized in that separation takes place by strip cutting and for producing the connecting portions the strip cutting is zonally interrupted.
3. Method according to claim 1 or 2, characterized in that separation takes place in such a way that in each case several, particularly three, transversely adjacent connecting areas form a cohesive group and that cohesive groups are transversely separated from one another.
4. Device for manufacturing padding material from inherently rigid flat material, with a cutting mechanism (5) having two cooperating, oppositely drivable cutting rolls (7, 9), each of which has a plurality of cutting disks (13, 41, 50, 51, 52, 57, 59), which are axially bounded by cutting edges (16) and between which are provided axial gaps (14) in each of which engage cutting disks of the other cutting roll for producing a cutting engagement, the cutting disks being so constructed that cutting engagement between adjacent cutting disks is interrupted at least once during a rotation of the cutting rolls.
5. Device according to claim 4, characterized in that the cutting disks (13, 41, 50, 51, 52, 57, 59) have at least one of the following features:

   they have circular circumferential surfaces interrupted by at least one circumferentially extending slot (43, 44, 53, 54, 56, 58),

   the slot has a depth (48) equal to or greater than a maximum overlap (49) of the cutting disks,

   at least one of the cutting disks has an even number of regularly circumferentially distributed and optionally two diametrically facing slots (43, 44, 53, 54, 56, 58),

   in the circumferential direction a slot (43, 44, 53, 54, 56, 58) has an extension which is more than 1% and is preferably between approximately 2% and approximately 5% of the circumferential length of the cutting disk,

   the cutting rolls (7, 9) are so positioned with respect to one another than in an overlap area of the cutting disks a slot (56) of a cutting disk (57) of one cutting roll is positioned alongside a slot (58) of a cutting disk (59) of the other cutting roll,

   slots of adjacent cutting disks (41, 50, 51, 52) of a cutting roll are circumferentially mutually displaced by an even-numbered fraction of 180ø, particularly by 90ø.
6. Device according to one of the claims 4 or 5, characterized in that for stripping strip portions from the gaps (14) of the cutting roll a stripping device (33) is provided, which for each of the cutting rolls has an integral guide element, particularly guide plate (31, 32) engaging in the gaps (14) tangentially to the cutting shaft and which has slits for the passage of cutting disks.
7. Padding material, characterized in that it substantially comprises inherently rigid flat material, that the flat material (60) is separated into parallel strip portions (65, 66, 71, 72, 73) in such a way that transversely (69) adjacent strip portions are interconnected in the vicinity of longitudinally spaced connecting areas (67) and that strip portions between connecting areas are so deformed transversely to a neutral surface of the flat material that transversely adjacent strip portions are deformed in opposite directions.
8. Padding material according to claim 7, characterized in that groups of several, particularly three, transversely (69) adjacent connecting areas (67) are transversely separated from one another.
9. Padding material according to claim 7 or 8, characterized in that connecting areas (67) of individual strips or strip groups, considered longitudinally (68), are alternately transversely staggered.
10. Padding material according to one of the claims 7 to 9, characterized in that transversely (69) it can be drawn apart in elastically extensible and/or expanded metal-like manner.
11. Use of inherently rigid flat material for the manufacture of padding material according to one of the claims 7 to 10.

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