WO2003070426A1

WO2003070426A1 - Method and wide-strip sanding machine for sanding sheet-type materials

Info

Publication number: WO2003070426A1
Application number: PCT/CH2003/000107
Authority: WO
Inventors: Thomas RÄBER; Eugen HUNGERBÜHLER
Original assignee: Steinemann Technology Ag
Priority date: 2002-02-21
Filing date: 2003-02-14
Publication date: 2003-08-28
Also published as: AU2003203114A1; EP1476276A1; CH695723A5; DE50307421D1; EP1476276B1; ATE363962T1

Abstract

The invention relates to a device and a method for width-sanding sheet-type floor coverings and rubber printing bands that are uncoiled from cylinders and recoiled onto cylinders upon sanding. The material is repeatedly guided across a driven supporting roller and is continuously sanded on the opposite side thereof. According to the inventive device and method, the sheet-type material is sanded by means of a continuous sanding strip while being enveloped in part by the supporting roller. The inventive use of sanding strips results in a better sanding quality that is achieved in fewer sanding processes as opposed to cylinder sanding machines.

Description

_ _

Process and wide belt sander for grinding sheet material

Technical field

The invention relates to a method for wide grinding of web-like material, in particular floor coverings and rubber pressure tapes, which are unwound from rolls and rewound on rolls after sanding, the material being guided over a driven support roller and continuously sanded on the opposite side. The invention further relates to a wide grinding machine for grinding sheet material with a driven abrasive and a driven support roller.

State of the art

The first common characteristic of plastic floor coverings and rubber printing blankets for the printing industry is that a high-quality surface is required for both. The corresponding quality can only be achieved through a grinding process. The second common feature is that both are manufactured in relatively wide webs of 1 to 2 meters and more and are rolled up as a semi-finished product on rolls and, if necessary, wound up and down several times on rolls during the grinding process. According to previous practice, in the case of the rubber printing blankets, the web-like material is surface-treated about 10 times, initially as a calibration and finally as a fine sanding. In order to achieve the desired quality in the case of rubber printing blankets, not only must the highest surface quality be ensured, but also a thickness tolerance of ± 1 - 2 hundredths of a millimeter. This thickness tolerance applies not only over the entire length of the sheet material, but equally over the entire width of 1 - 2 meters and more. The quality requirements are enormous when the large physical dimensions of the rubber printing blankets are taken into account.

Floor coverings have similar problems. Only thickness tolerances of around ± 5 hundredths of a millimeter are required. The whole grinding process poses In a sense, it is a handicraft, since many manual interventions and control methods are necessary. The backup roller is usually a steel roller with a rubber jacket. The backup roller drives the endless belt. In the prior art, the grinding agent in cylindrical grinding machines is a cylindrical grinding roller. The rubber jacket of the back-up roller wears out and deforms after a long interruption because the rubber itself has a certain flow property. The rubber roller is ground with the cylindrical back-up roller after each long standstill and after a certain amount of wear.

Another problem is that the feed for the band-shaped material is slow and is about 0.5 to 1.0 meters per minute. This limits productivity. Due to the slow feed, a large part of the grinding heat is transferred to the grinding roller and the backup roller. These must therefore be water-cooled during the entire grinding operation.

The object of the invention was now to develop a method and a device which allow higher productivity and, as far as possible, energetically, e.g. in terms of cooling performance, bring an improvement.

Presentation of the invention

The method according to the invention is characterized in that the web-like material is partially grinded around the support roller by means of an endless sanding belt stretched between deflection rollers.

The broadband sanding machine according to the invention is characterized in that the driven abrasive is designed as a sanding head with an endless sanding belt, which can be tensioned between deflection rollers, and that a deflection roller for the web-shaped material is arranged at least on one side of the support roller.

The inventors have recognized that the "bottleneck" in the prior art is primarily the removal of the grinding heat. The backup roller is provided with a rubber jacket. This means a very poor heat transfer from the web-like material into the interior of the roll. In the case of cylindrical grinding machines, the grinding roller must have a remarkably high rotational speed of, for example, 20 - 30 m / sec. are driven so that the temperature is approximately the same everywhere on the circumferential surface of the roll. The heat can therefore only be dissipated inside. Due to the poor heat flow or heat build-up the grinding point must be limited. The sheet-like material consists both of floor coverings and of rubber pressure tapes from relatively soft plastics, which allow only a limited thickness removal in one pass during the calibration grinding.

The new solution proposes to design the abrasives as an endless sanding belt. The endless sanding belt has the great advantage that, apart from the good sanding work, the sanding cloth is fed to and removed from the sanding point and, due to its low mass, can quickly give off heat outside the sanding point. After one cycle, the sanding belt has cooled down to about ambient temperature again, so that most of the heat can be dissipated via the sanding belt. This brings surprisingly great advantages. In the prior art, the feed of the band-shaped material was usually below 1 m / min. set. In the case of rubber printing blankets, about 10 passes were generally required for the calibration and fine sanding. The new solution allows a feed rate of up to 5 m / min. and more. Rubber printing blankets can now be sanded in a total of 5 passes. Even if the manufacturing effort for a sanding head with an endless sanding belt is a multiple compared to a sanding roller, the enormous gain in productivity brings many more advantages, since the time required for sanding floor coverings and rubber pressure belts can be reduced to a fraction. The sanding belt offers a large sanding area at the sanding point and allows a longer service life and an improvement in quality and tolerance. A very big advantage of the new solution is that the water cooling is completely eliminated, as was absolutely necessary in the prior art for cylindrical grinding machines.

The new invention allows a number of particularly advantageous configurations. For this purpose, reference is made to claims 2 to 1 1 and 13 to 21.

The web-shaped material of the driven support roller or the grinding point is preferably fed in and out with approximately the same tensile stress. This can ensure consistency for the grinding conditions, since only the changing forces from the grinding work occur at the grinding point. The forces from the grinding work or the forces generated by the grinding belt are compensated for by the driving forces of the support roller. For this purpose, the web-shaped material is wrapped with at least about 30 °, preferably more than 45 ° the driven support roller (angle α) guided to allow sufficient static friction for the power transmission.

Advantageously, the feed speed for the sheet material is in a range from 0.5 to 5 m / min. or more adjustable. A very important point is that the speed of the sanding belt is as infinitely variable as possible from 15 to 35 m / sec. is adjustable, e.g. with a frequency converter and a three-phase motor. An optimal speed for the sanding belt is 15 to 25 m / sec for calibration grinding and 25 to 35 m / sec for fine grinding.

Experience has shown that excellent results are achieved when the speed of the web-shaped material is in the range of 2 to 4 m / min for the calibration grinding and in the range of 1 to 2 m / min for the fine grinding. lies. The web-shaped material for continuous grinding is unwound from a roll, raised in a loop-like manner to the grinding point via the support roller and wound up again on a roll after grinding. The grinding process takes place in several stages, the web-like material possibly being returned several times between the individual stages in the opposite direction to the unwinding side. It is particularly advantageous to change the sanding belt during the return of the web-shaped material and to use it for the subsequent sanding process for the calibration sanding from P 120, 220 to 280 and for fine sanding, e.g. P 280, 400 and 1000 can be used. The grinding process can also take place in several stages, the web-shaped material being carried out continuously by two or more grinding stages. According to a further design concept, both the bottom and the top can be ground in succession. In the case of calibration grinding in particular, the grinding point is formed between a contact roller running along with the grinding belt and the support roller. In the case of fine sanding, the sanding process takes place between two deflection rollers and the backup roller with a slight wrap around the backup roller and pressure on the backup roller. It is advantageous if the contact roller can be adjusted and removed and is adjusted for calibration and removed for fine sanding.

According to a further design concept, the support roller is designed such that it can be moved in and out in the direction of the web-shaped material, such that in the delivered position the web-shaped material partially wraps around the support roller for transmitting the driving force. The back-up roller is put away for the return and allows a free passage of the band-shaped material. The abrasives are designed as a grinding head, the grinding head in the two end positions either having at least one driven and / or at least one idling roller. The dimensions between the deflection rollers, perpendicular to the transport direction of the web-shaped material, are advantageously a multiple in relation to the diameter of the support roller. For the sanding belt, this results in a multiple of the total sanding belt area in relation to the peripheral area of a sanding roller according to the prior art.

A deflecting roller is preferably designed as a contact roller, for pressing the grinding belt onto the support roller, in particular for a calibration grinding. At least one other roller is designed as a tension roller. According to a further advantageous embodiment, the grinding head has at least one calming and tensioning roller in the vicinity of the pressure rollers on the sanding belt feed and / or on the sanding belt path guide side. On both sides of the wide grinding machine there is a roll-up or roll-off station, which control or Control means are assigned to compensate for the tensile stresses before and after the grinding point. Furthermore, a guide roller is arranged on each side of the support roller. The support roller can be moved in and out such that a strong wrap of the web-shaped material can be set in the grinding operation and a free passage without contact with the support roller can be set for the web-shaped material when idling.

Brief description of the invention

The invention will now be explained in more detail with the aid of some exemplary embodiments. Show it:

Figure 1 schematically shows an overview of the entire grinding process; 2 shows the grinding zone for a calibration grinding; 3 shows the grinding zone for a fine sanding; FIG. 4 shows an entire grinding assembly in use for a calibration grinding; FIG. 5 shows a grinding assembly with a lowered support roller and free passage for the web-like material; FIG. 6 shows an example of a combination of Frein calibration grinding; FIG. 7 shows a view for the grinding assembly according to arrow VII; FIG. 8 shows the grinding assembly of FIG. 7 in a side view; FIGS. 9 and 10 show a side view and a floor plan of several grinding assemblies arranged in series. Ways and implementation of the invention

In the following, reference is now made to FIG. 1, which represents an overview of the grinding process. The strip-like material 1 is unwound from the roll 2 (on the right in the picture), fed to the grinding point 4 in the direction of arrow 3 and wound up again with the roll 5. The grinding point 4 is formed by a support roller 6 and a contact roller 7. The abrasive is an endless sanding belt 8, which is stretched between the contact roller 7 and a deflection and tension roller 9. The sanding belt 8 essentially forms the outer contour for a grinding head 10. Above the contact roller 7, two calming rollers 11 are arranged, which essentially ensure a smooth and smooth running of the sanding belt. Previous practical tests have shown that it is advantageous if a calming roller is arranged on both sides, near the grinding point, on the sanding belt inlet side and on the sanding belt outlet side. At the same time, the endless sanding belt 8 is tensioned at the locations of the calming rollers. It has also proven to be advantageous if the endless sanding belt both over the deflection or. Tension roller 9 is driven as well as via the contact roller 7. The direction of movement of the endless sanding belt in the direction of arrow 12 is opposite to the transport direction of the web-like material 1 (according to arrow 3). In the lower area of the grinding head 10 there is a pressure roller and a deflection roller 14, 15 on both sides of the grinding point, which, as indicated by the dimensional arrows, vertically between a lower (U) a middle (M) and an upper ( O) position are adjustable. Within the contact roller 7, an arrow 13 indicates a corresponding vertical adjustability of the contact roller 7. These two adjustment options allow the optional addition (or removal) of either the pressure and deflection rollers 14, 15 or the contact roller 7.

The web-like material 1 is guided before and after the support roller 6 by a respective guide roller 16 and 17, so that a good wrap with an angle α greater than 30 ° is ensured by a corresponding displacement of the guide rollers 16, 17 to the support roller 6. Between the guide rollers 16 and the roller 17, respectively. the guide roller 17 and the roller 2 is a sensor roller 18 respectively. 19 arranged. With the sensor rollers 18 and 19, the tension in the band-shaped material is continuously determined. As soon as the tensile stresses on the two sides of the grinding point are different, the winding or unwinding speed at reel 2 and / or 5 is changed immediately until the tensile stresses on both sides of the grinding point match again. Each side is preferred one optimal tensile stress is given as the setpoint and the opening or closing Processing speed of rolls 2 and 5 regulated accordingly. Each role is assigned a support frame 20 with two rollers 21 and 22, on which rotary stub 23 of the roles 2 and. 5 run. If the band-shaped material is completely conveyed from one side to the other, the material can be rewound. When the grinding process is complete, the full roll can be lifted off and replaced with a new, unprocessed one. The two reeling and unwinding stations preferably form special assemblies and are connected to the grinding assembly or its control only by means of the band-shaped material 1 and the control and sensor lines described.

Figures 2 and 3 each show the grinding point on a larger scale. FIG. 2 shows the calibration or the thickness cut. The contact roller 7 is lowered and pressed onto the support roller 6 with slight pressure, as indicated by arrow 17. The two pressure and deflection rollers 14 and 15 are in an upper position between M and O and result in a very light wrap around the contact roller.

Figure 3 shows a disposition for fine tuning. The backup roller 6 is unchanged. The contact roller, on the other hand, is in the raised position, as indicated by arrow 13. The two pressure and deflection rollers 14 and 15 are in a lower position between M and U. The endless sanding belt 8 is pressed onto the support roller by the two pressure and deflection rollers 14 and 15 in such a way that a slight wrap arises, as is held at angle β is. This means that a large sanding surface can be created for fine sanding in any case, so that very intensive and stable or reproducible sanding work is possible and thus fewer passes are required, but the sanding quality is nevertheless better. It is possible to wrap ß e.g. to move more on the inlet side (right). The deflection roller 14 is lowered more, e.g. to point U and the guide roller 1 5 less lowered e.g. close to the marking M. The endless sanding belt 8 is thereby brought into a slight inclined position in the area of the sanding point.

FIG. 4 shows a complete grinding assembly, which has a stand 30 and stands on the floor 31. Below the support roller 6 is a lowerable carrier 32 on which the support roller 6 is mounted. The carrier 32 is supported on the left side on pivot 33 and held on the right with a lock 34. As soon as the lock 34 is released via the cylinder 35, the carrier 32 can be lowered by means of the cylinder 36. The lowered position is shown in FIG. 5. Since sanding dust inevitably arises from the sanding work, it is extracted at various points. A suction 40 is arranged in the upper region of the grinding head 10. Here the grinding dust is sucked off the endless grinding belt 8. The ground surface of the band-shaped material after the grinding point is cleaned with a suction device 41. The web-shaped material 1 is shown in dotted lines and shows the effective passage during the grinding process. Figure 4 is a concrete embodiment. This clearly shows that the surface of the endless grinding belt 8 is a multiple of the surface of the support roller 6. In the prior art, the grinding roller in cylindrical grinding machines corresponds approximately to the geometric dimensions of the support roller 6. The suction 40 does not only clean the endless grinding belt 8 , but it takes place with the remarkably large amount of air that is passed through, a cooling of the endless sanding belt 8.

FIG. 5 shows a grinding station for the calibration grinding and corresponds in terms of function with respect to the calibration grinding of FIG. 2. The endless grinding belt 8 is guided around the contact roller 7 in the area of the grinding point. The support roller 6 is drawn in the lowered position, so that the endless sanding belt runs almost flat through the entire sanding station 40. This is always the case when the web-shaped material for the next grinding process is returned at idle and wound up again on the first roll. The grinding time for a complete run is e.g. 4 to 6 hours, but can also take an entire working day and more. With the new solution, this allows the continuous sanding belt to be changed from a coarser to a finer grit. A sanding belt change takes only 3 to 5 minutes. This means that no productive grinding time is lost when changing the sanding belt. In Figure 5, several suction points are also shown. A suction point 41 is located before and a suction point 42 after the grinding point, in both cases on the underside of the endless material 1. On the grinding side or the top of the endless material there is a suction 43 and 44 in front of the grinding point, after the grinding point a suction 45 which extends over the entire height of the grinding head 10 'and correspondingly sucks and cools the endless grinding belt. Another suction 46 is attached to the grinding head at the top right.

FIG. 6 shows a double version with a combined calibration and fine grinding unit 50 according to FIG. 1 and a fine grinding unit 51 (without contact roller 7). In Figure 6 is also for the backup roller and for the top of the web-shaped material, one brush roller 52 each. Depending on the setting, the solution according to FIG. 6 allows:

- just a rough cut,

- a rough sanding and a fine sanding or

- two finishing touches.

Figures 7 and 8 show a front view (Figure 7) and a side view (Figure 8) of a combined grinding unit. FIG. 7 shows the main motor 60, a belt overdrive 61 and a second drive shaft 62. Both the guide rollers 9 and the contact rollers 7 are driven. Reference number 63 denotes the electrical control cabinet and 64 a superordinate machine control system with memory and computer means. The grinding process is a continuous process. Once set, the grinding work can be carried out without monitoring until the entire material of a roll has been sanded. However, this requires a high tax and control effort. This affects not only all control and regulation processes, but also the process control itself. All motors, cylinders, tensile stresses, speeds must be monitored, e.g. with regard to a tape tear, a security intervention e.g. as an emergency stop. Recipe specifications can be made and the actual states determined can be saved and later used again or used for improvements. An operating panel with a screen 61 is arranged on the machine itself. A PLC control is also arranged in the control cabinet 64.

Figures 9 and 10 show several grinding stations in series, top in a side view, bottom in a top view. The example shown is a calibration grinding unit. It is interesting that in the first two grinding units 70, 71 the grinding head is arranged at the bottom. The underside of the endless material is sanded. In the two grinding units 72, 73, the grinding heads are arranged at the top. The upper side is thus sanded. In one pass there are two grinding processes at the top and two grinding processes at the bottom.

Figures 6, 9 and 10 are only examples. Of course, any combination of fine or large grinding units can be selected within the scope of the new solution or the new invention, depending on the specific task. As a rule, more passes will be required for rubber pressure tapes or similar products and fewer passes for floor coverings or similar products.

Claims

claims

1. A method for wide grinding of web-like material, in particular floor coverings and rubber pressure tapes, which are unwound from rolls and rewound on rolls after grinding, the material being guided over a driven support roller and continuously sanded on the opposite side, characterized in that the web-like material with partial wrapping around the support roller is ground by means of an endless sanding belt stretched between deflection rollers.

2. The method according to claim 1, characterized in that the web-shaped material of the driven support roller or the grinding point is supplied and discharged with at least approximately the same tension.

3. The method according to claim 1 or 2, characterized in that the web-shaped material with at least about 30 °, preferably more than 45 ° wrap, is guided over the driven support roller.

4. The method according to any one of claims 1 to 3, characterized in that the feed speed for the web-shaped material in a range of 0.5 to 5 m / min. or more is adjustable.

5. The method according to any one of claims 1 to 4, characterized in that the web-shaped material for continuous grinding is unwound from a roll, raised in a loop-like manner at the grinding point via the support roller and wound up again on a roll after grinding.

6. The method according to claim 5, characterized in that the grinding process takes place in several stages, the web-like material being returned between the individual stages in the opposite direction in each case on the unwinding side.

7. The method according to claim 5, characterized in that the grinding process takes place in several stages, the web-shaped material being continuously passed through two or more grinding stages.

8. The method according to any one of claims 1 to 7, characterized in that the grinding point is formed between a contact roller running in the same direction with the grinding belt and the counter-rotating support roller.

9. The method according to any one of claims 1 to 7, characterized in that the grinding process between two deflecting rollers and the backup roller, a slight wrap around the backup roller and a pressure on the backup roller.

10. The method according to claim 8 or 9, characterized in that the contact roller is adjustable and removed and is delivered for calibration and is removed for fine sanding.

11. The method according to any one of claims 1 to 10, characterized in that the support roller in the direction of the web-shaped material is adjustable and removed, such that in the delivered grinding position, the web-shaped material partially wraps around the support roller for transmission of the driving force and in the removed positions allows a free passage for the sheet material.

12. Wide grinding machine for grinding web-shaped material with a driven abrasive and a driven support roller, characterized in that the driven abrasive is designed as a grinding head with an endless sanding belt, which can be stretched between deflection rollers, and that at least on one side of the support roller a deflection roller for the web-shaped material is arranged.

13. wide belt sander according to claim 12, characterized in that the dimension of the grinding head perpendicular to the transport direction of the web-shaped material is a multiple in relation to the diameter of the support roller.

14. Wide belt sander according to claim 12 or 13, characterized in that the grinding head in the two end positions either has at least one driven and / or at least one idling roller.

15. wide belt sander according to claim 14, characterized in that a deflecting roller is designed as a contact roller, for pressing the grinding belt onto the support roller, in particular for a calibration grinding, and at least one other roller as a tension roller.

16. Wide belt sander according to claim 14, characterized in that the grinding head in the region of the support roller at a distance before and after the support roller each has a pressure roller and deflection roller, such that the sanding belt for fine sanding between the two pressure rollers and deflection rollers is easier Wrapping around the support roller can be pressed.

17. Wide belt sander according to one of claims 14 to 16, characterized in that the grinding head in the region of the support roller has three pressure rollers, two pressure and deflection rollers arranged at a distance before and after the support roller and a contact roller directly vertically above the support roller and to - and is removable.

18. Wide belt sander according to claim 17, characterized in that the two pressure and deflection rollers can be moved in and out for an optional use of the grinding head as a calibration or fine sanding.

19. Wide belt sanding machine according to one of claims 12 to 18, characterized in that the sanding head in the vicinity of the pressure rollers on the sanding belt feed and / or on the sanding belt removal side has at least one calming and tensioning roller.

20. Wide belt sanding machine according to one of claims 12 to 19, characterized in that a roll-up or roll-off station is arranged on each side of the wide-belt sanding machine, which have control or regulating means for regulating the tension of the web-shaped material from and to the grinding point, preferably on the basis corresponding sensor signals in the area of the grinding point.

21. Wide belt sander according to one of claims 12 to 20, characterized in that one guide roller is arranged on each side of the support roller, and the support roller can be moved in and out such that a strong wrap of the web-like material and in idle for the web-like material in the grinding operation a free run without contact with the backup roller is adjustable.