DE1901365A1 - Method for severing at least one partial web - Google Patents

Description

Annex to the submission of December 31, 1968 procedure for separating at least a partial track.

The invention relates to a method for separating at least one Partial web of a wide material web wound onto a roll, in particular Paper or cardboard using a rotating knife.

The cutting of wide webs of material wound into supply rolls usually takes place in such a way that these webs from the supply roll to a second Roll wrapped around and thereby the running between the two rollers web part by means Upper and lower knife cut. Should be taken from the supply roll after this procedure a paper roll with a smaller width can be divided, while the remaining part the paper is still being used, so the paper web is also completely wrapped, that is to remain in stock is required from the supply roll to another roll.

In order to avoid this effort, it has already been suggested by Cutting knife to divide a supply roll and only the separated web from the supply roll to handle.

With this procedure, however, the cut easily becomes messy and it if choking, shreds, fringes appear along the cut, which is what is common today, relatively high web speeds leads to breaks in the web and therefore only for low speeds is applicable.

The object of the invention is therefore to show a method that allows the separation of material webs on the roll at high speeds, without damage or breaks in the web affecting the separation process.

This technical problem is addressed by a method of separation at least a partial web of a wide material web wound onto a roll, in particular Paper or cardboard, solved by means of a rotating knife that a heat build-up on the rotating knife 9 is prevented.

The inventive method is initially achieved that the knife only insignificantly heated, which for the.

As a result, steel used in the manufacture of knives no longer glows out and the knife's ability to cut remains intact over a longer period of time.

Another advantage arises compared to the processed product. The fact that the knife as such only heats up slightly is also transfer only a little heat to the product to be cut, i.e. that neither the End face remaining when a partial web is cut, nor the cut web heat up significantly and therefore there are no undesirable effects such as bpLelsweise Bonding of film webs in the area of the separation zone or "burning" of the paper when cutting paper webs. All three listed options result individually or in combination to tear off the material web. By switching off the Knife heating will result in tears that can be traced back to this cause, certainly avoided.

There is a preferred device for carrying out the method in a device in which the knife shaft is used to avoid the build-up of heat on the knife of the cutting unit runs at an acute angle to the axis of the roll of material.

This arrangement creates between knife and stopping Roller face has a free angle, i.e. there is no excessive heat-generating There is friction, as the knife only engages the material roll at the point of separation stands, so essentially point-like or linear and not flat. Through the Reducing the friction will besides avoiding the heating of the knife as well the mechanical load on the cutting unit is reduced, the knife is less worn and the drive power of the knife shaft can be designed lower. When cutting of paper and cardboard is contributed by the clearance angle, he by the cutting process the accumulation of dust arising from the fragmentation of the fibers can be significantly reduced, so that the finished product is cleaner and does not interfere with paper dust when printing and leads to errors in the print.

In an expedient configuration of the device, the Angle between knife shaft and material roll 1.5 - 8 °.

The resulting clearance angle between the perpendicular to the Knife shaft seated circular the square knife and the material roll face is therefore in the same range. By choosing a very small clearance angle between 1.5 and 8 ° there is an increase in friction between the usually conical designed knife and the underlying piece of web to be cut avoided, the knife can thereby be made of stronger material and with the usual Cutting angles are provided.

The danger of using extremely thin knives through mechanical Damage occurs - e.g. the knife becomes chipped or broken thereby also eliminated.

A particularly advantageous embodiment of the device according to the invention is that the angle between the knife shaft and the roll of material is adjustable is. The adjustability of this angle makes it possible> with the same device to process a wide variety of materials and always achieve the best possible cutting performance to reach.

For example, cutting metal foils such as aluminum foil requires any setting other than cutting plastic film, e.g. polyethylene film.

Another preferred embodiment of the invention consists in that the knife is provided with cooling fins. By mistaking the knife or the knife hub with cooling fins or lamellas is due to the relatively high speed of the knife a strong air movement is achieved. This LuCtbewegung, which expediently by special design of the ribs is directed to the knife edge, brings a further additional cooling of the knife without any significant effort, which is particularly is desirable when dividing plastic sheets.

In a further expedient embodiment of the invention, the knife charged with cooling air. The knife application with cooling air is particularly then very advantageous if several narrow lanes are to be separated at the same time, the knives are very visible and, for reasons of space, the use of VJn with wings equipped knife hubs for cooling is not possible.

According to a further preferred embodiment of the invention is the knife speed is C, 5 to 1.2 times the maximum web speed. The peripheral speed of the knife and the 3-tooth speed, i.e. the speed with which the severed partial web is pulled from the roll, are in a certain relationship to each other. With a knife that rotates relatively slowly is from a point on the circumference of the knife - same path speed at all knife speeds provided - a much larger part of the material web cut through.

The knife is heated for a long time at this point, i.e. it a higher temperature is reached on the knife.

At the same time, there is greater mechanical wear on the knife. By increasing the blade speed, these disadvantages are reduced to a certain extent the point which is dependent on the path speed and which is reached when every point of the material web comes into contact with a new point on the knife, so the theoretically most favorable value is achieved. By further increasing the speed if a point of the material web is touched by a larger circular arc of the knife, whereby the material web is unnecessarily heated at this point. An essential one Increasing the blade speed therefore also leads to malfunctions in the cutting device.

The different materials to be processed however, oppose different levels of resistance to separation. They make a difference differ in hardness, elasticity and elasticity, so that depending on the part to be divided Material from the theoretical maximum value "knife speed = material web speed" there are deviations upwards and downwards. The speed of the knife shaft is therefore preferably infinitely variable.

A particular advantage of the invention is that it is now possible is to process directly from the machine-wide web, so that further processing companies Now, in an efficient way, separate partial webs directly from machine-wide rolls and can process them without the great expense of expensive rewinding devices to have to drive.

However, the invention is also applicable to the manufacturer of the web-shaped materials valuable, which is not immediately processed further, since it is no longer now it is necessary that the machine width as a whole will be smaller in partial webs Sreitg, but only one section can be separated at a time. So can be with the separation; of the machine-wide web in partial webs Process a very specific order without the need for additional rolls with part-width sections remain that are not needed for a long time.

Further advantages and details of the invention are shown in the drawings to enrnenmen that a preferred embodiment as a schematic representation Example shows.

Figure 1 is the front view, Figure 2 is the side view of a partial web severing device.

The cutter head 1 already has several layers from the roll of material 2 the partial web S separated. The button 4 of the cutter head 1 is on the trigger from several layers of the partial web 3 tapered material roll piece 2 a. hoof that The drive unit 6 is placed on the frame 5, and the knife shaft via the belt drive 7 8 drives with the knife 9 mounted on it. The material rail 2 is thereby through the cone 1G is fixed on the unwinding shaft 11, the unwinding shaft 11 is in the bearing blocks 12 and 13 stored. By operating an adjusting device not shown is the one formed between the unwinding shaft 11 and the axis of the roll of material 2 - Ö Angle α adjustable. Its size corresponds to the clearance angle; between the end face of the roll of material 2 and the rotating knife 9. The rotating Blade 9 is provided with a blade-tipped hub 14 through which, when it rotates of the knife 9 an air movement is generated, which the knife 9 and the severed Lane 3 cools.

Claims (7)

Annex to the entry from December 31, 1968 Claims 1. A method for severing at least one partial web from a wide web of material wound on a roll, in particular paper or cardboard by means of a rotating knife, characterized in that there is a build-up of heat on the rotating knife (9) is prevented. 2. Apparatus for performing the method according to claim 1, characterized characterized in that to avoid heat build-up on the knife (9) of a cutting unit the angle (α) between the knife shaft (8) of the cutting unit with perpendicular to the rotating knife (9) and the axis of the roll of material (2) an acute angle is. 3. Apparatus according to claim 2, characterized in that the angle (α) is between 1> 5 and 3-. 4. Apparatus according to claim 2 and 3, characterized in that the angle (α) between knife shaft (8) and material roll (2) is adjustable is. 5. Device according to one of claims 2 to 4, characterized in that that the knife () is provided with cooling fins. 6. Device according to one of claims 2 to 5, characterized in that that the knife (9) is supplied with cooling air. 7. Device according to one of claims 2 to 6, characterized in that that the knife speed is C, - 1.2 times the maximum web speed is.