EP0754159B1 - Method of initiating the premature replacement of a roll of material - Google Patents

Abstract

PCT No. PCT/EP95/01282 Sec. 371 Date Sep. 26, 1996 Sec. 102(e) Date Sep. 26, 1996 PCT Filed Apr. 7, 1995 PCT Pub. No. WO95/27676 PCT Pub. Date Oct. 19, 1995A process for initiating a premature roll change of a web to be unwound from a roll wound on a spool, the process including the steps of measuring temperature at an end of the roll in a zone up to 150 mm away from a surface of the spool in a radial direction during a time that the roll has between 100% and 60% of its fully wound weight, using a non-contact measuring device, determining a radial distance from the spool surface when a temperature difference>/=0.5 DEG C. is found between temperature measurement locations in the zone and cooler adjacent areas, and storing the determined distance for triggering a signal that initiates a replacement of the roll when that distance is reached.

Description

The present application relates to a method to initiate an early role change a web to be unwound from a sleeve, especially a paper web.

The term "sleeve" stands for Drums, cardboard or metal winding cores.

In all winding processes, especially in the Paper industry are becoming bigger and bigger roles sought. This applies to the diameter and the Width. However, the wrapping technique belches open physical limits that a complete Do not use the wound web quantity allow. Inside the rolls, i.e. H. in the so-called core area, directly on or directly Destruction occurs over the sleeve, such as Path tearing, so-called core burst or Crepe folds on. The following are these Apparitions referred to as defects. Continue complicating the fact that these flaws only statistically with widely fluctuating frequencies occur.

This inevitably leads to the web being torn off in the following processing machines corresponding downtimes and material losses. For security reasons, the role is therefore not completely processed, but it will a substantial amount of residual paper on the sleeve leave it as a committee of the Reprocessing must be fed.

Like Jühe in the DE reference: Practical experience in manufacturing wider Large diameter gravure rolls, published in: Das Papier, 45th year 1991, Booklet 10a, pages V73 to V78 was reported Already tried errors, such as B. Wrapping folds and bars during the winding with stroboscopic lighting for human To make the eye visible. Still, too still a considerable number of large rolls wrapped on hospital scooters for control purposes, for clues to the possible presence of To receive defects, or their emergence have not yet been identified from the outside could. From the mentioned literature reference further shows that "problem areas close to the Sleeve (core positions) "obviously only arise during unwinding at So winding up is not yet recorded can. Off when unrolling a large one Tambours detected temperature changes, d. H. a systematic increase in temperature of the drum core - as a result of pressure changes - and bending stresses and sliding movements in the Kern - the idea is derived, a further examination and assessment procedure for to develop the winding technology. As characteristics for winding quality see page V76, right column u. a. the role hardness, the Role structure, the role surface and the Roll shape specified. A suggestion for Development of a method to determine possible defects could serve not yet given in the literature.

The object of the present invention is to achieve this to provide a process that in the manufacture of rolls with large Roll diameter and large web width, especially in the paper industry, a Possibility to determine im Creates core areas occurring defects, so that the production of large rolls up to Exploitation of their physical winding limits is made possible and that on the sleeve necessarily remaining number of layers is minimized.

The inventors have now recognized that within of a particular one lying adjacent to the sleeve Range of layers of the paper web certain Temperature phenomena can occur that lead to take advantage of early detection of defects let and initiate a role change allow before it through the flaws too a demolition of the web comes. With the mentioned Temperature phenomena are point or flat spots with a few tenths ° C increased temperature. These places are not to be confused with ring-shaped Temperature phenomena, which are also in the Core area are observed and compared to the layers further away from the sleeve have a high temperature on a web.

• mit einer berührungslosen Temperaturmeßeinrichtung wird, während die Rolle beim Auf- oder Abwickelvorgang 100 % bis 60 % ihrer Masse aufweist, stirnseitig in einer Zone, die bis zu 150 mm in radialer Richtung von der Oberfläche der Hülse entfernt ist, die Temperatur gemessen,
• bei einer festgestellten Temperaturdifferenz von ≥ 0,5 °C zwischen punkt- oder flächenförmigen Temperaturstellen innerhalb der Zone und den kühleren benachbarten Bereichen wird der radiale Abstand von der Hülsenoberfläche ermittelt,
• der ermittelte Abstand wird zur Auslösung eines Signals, das den Rollenwechsel bei Erreichen des Abstandes auslöst, abgespeichert.

Using the newly gained knowledge, the invention therefore proposes a method for initiating a premature roll change of a web to be unwound from a sleeve, in particular a paper web, which is characterized by the combination of the following features:

• with a non-contact temperature measuring device, while the roll has 100% to 60% of its mass during the winding or unwinding process, the temperature is measured on the end face in a zone which is up to 150 mm in the radial direction from the surface of the sleeve,
• with a determined temperature difference of ≥ 0.5 ° C between point or area temperature points within the zone and the cooler neighboring areas, the radial distance from the sleeve surface is determined,
• the distance determined is stored in order to trigger a signal which triggers the roll change when the distance is reached.

As tests on the windings of two paper machines have shown, the temperature development measured on the face of the paper roll shows the following typical course in approx. 90% of the measurements, although there is no serious difference between individual grammages - raw paper weight between 32 and 48 g / m ² - or types of paper:

First of all, the paper comes with a high Temperature from the dryer section of the Paper machine. In the further course of the The temperature in the core area drops at first, the further the drum goes away from the nip. The mass of the paper roll grows over 60% of the final mass of the finished roll, sounds the trend of falling temperature in the Core area clearly. The trend is falling Temperatures reversed, and the temperature rose in a zone that is about 5 to 150 mm, especially 10 to 80 mm, from the surface of the Sleeve is removed. It formed only a few mm wide within the zone annular temperature point in the edge area of the Role. Detected temperature differences of ≥ 0.5 ° C at points or areas inside the narrow annular Temperature point - compared to cooler ones adjacent areas of the annular Temperature point - indicate defects that demolition in the subsequent processing being able to lead.

By the knowledge of the inventors, according to which Extent of temperature increase with errors in Core area of the role is coupled the method according to the invention for the first time Temperature monitoring the detection of Missing parts. With an advantageous Embodiment of the first method takes place Monitoring both end faces of the role, since that Occurrence of defects arbitrarily in the Edge area on one of the two sides can and in no way on both sides at the same time must occur.

Since it has been shown that at the start of processing, just like towards the end of winding up on the Paper machine, the training of point or surface heating in the vicinity of the sleeve Edge area of the role occurs, it plays in principle it does not matter whether the Temperature monitoring on the winding or unwinding he follows.

If no abnormality is registered, the Processing process as requested by the processor and for the best possible material utilization optimized.

On the other hand, if a critical value is displayed, i.e. H. a determined temperature difference of ≥ 0.5 ° C towards cooler neighboring areas, would as the simplest form of reacting, the output an alarm for the machine operator as An indication of a defect is sufficient.

The automation provided according to the invention to initiate an early role change, wherein control signals of the temperature measuring device has triggered a role change process however, for obvious reasons, superior proven.

The inventors found that with coated papers the formation of punctiform or sheet-like places with increased temperature is more pronounced than with uncoated paper. When unwinding coated LWC paper with a weight per unit area of 75 g / m ^2, there were temperature differences of up to 1.6 ° C at the beginning of the unwinding. The temperature of the rollers is preferably measured on both end faces.

• während die Rolle im Bereich von 100 mm von der Hülsenoberfläche entfernt bis zum Ende abgewickelt wird, wird oberhalb der abzuwickelnden Warenbahn eine berührungslose Temperaturmessung im Randbereich sowie im Mittenbereich der Rolle durchgeführt,
• durch Ermittlung einer Temperaturdifferenz im Randbereich der Rolle im Vergleich zum Mittenbereich von > 0,5 °C wird durch von der Temperaturmeßeinrichtung ausgelöste Steuersignale ein vorgezogener Rollenwechsel eingeleitet.

According to a second proposal, as specified in claim 3, the invention provides a method for initiating a roll change of a web to be unwound from a sleeve, in particular a paper web in web printing presses, which is characterized by the combination of the following features :

• while the roll is unwound to the end in the area of 100 mm from the sleeve surface, a contactless temperature measurement is carried out above the web to be unwound in the edge area and in the middle area of the roll,
• By determining a temperature difference in the edge region of the roll in comparison to the central region of> 0.5 ° C., an early roll change is initiated by control signals triggered by the temperature measuring device.

Although the higher heat development in the core area the role with large roll mass at the beginning of the Development process can be created locally warmed spots that indicate defects, even with an advanced unwinding process measure. This works because it is local warmed up spots during processing due to heat flow to the environment have it demonstrated in a larger area. The decisive factor is the temperature difference between the center of the roll and the edge areas. The enables second method according to the invention therefore by means of temperature monitoring early detection of defects, if frontal access to the roll is not possible is like at the unwind station of Web presses often from constructive Reasons.

Had in the second method according to the invention proved to be particularly advantageous, the Temperature measurement by an infrared camera, the is equipped with a linear guide, traversing across the entire width of the roll to be done. A calculator evaluates that Temperature profile across the entire width of the roll out. If a specified one is exceeded Temperature difference between center and Edge area of the roll is a control signal to the Exchange device for triggering the Exchange process issued.

According to the invention, infrared cameras have a resolution accuracy of at least 0.2 ° C proven. The ambient temperature at which the Measurements take place is on average 30 ° C.

The methods of the invention are not only based on the winding of webs of paper applicable. Even when winding material webs out Plastic fibers or foils are created with growing role mass warming in the core area the role.

Figur 1 die Stirnseite einer Rolle mit skizzenhafter Darstellung einer ringförmigen Temperaturstelle und einer punktförmigen Stelle mit erhöhter Temperatur,

Figur 2 eine räumlich angeordnete schematische Darstellung des ersten erfindungsgemäßen Verfahrens gemäß Patentanspruch 1,

Figur 3 eine schematische Darstellung des zweiten erfindungsgemäßen Verfahrens nach Patentanspruch 3,

Figuren 4 und 5 Infrarot-Temperaturaufnahmen mit lokaler Temperaturerhöhung, aufgenommen von der Stirnseite der Rolle.

The following figures serve to explain the invention in more detail. Show it:

FIG. 1 shows the end face of a roller with a sketchy representation of an annular temperature point and a point-like point with increased temperature,

FIG. 2 shows a spatially arranged schematic illustration of the first method according to the invention according to patent claim 1,

FIG. 3 shows a schematic illustration of the second method according to the invention according to patent claim 3,

Figures 4 and 5 infrared temperature recordings with local temperature increase, taken from the front of the roll.

FIG. 1 shows the end face of the completely wound roll (1) shortly before it is ejected from the rewinding of a paper machine, not shown. The roller (1) has a finished diameter of d _max = 3.2 m and an inner diameter or sleeve diameter of d _H = 560 mm. The area of the sleeve (2) is hatched. A ring-shaped temperature point (5) a few mm wide and shown as a thick chain line is located within the zone marked Z = 150 mm in the radial direction. The dashed circle (4) corresponds to 60% of the finished diameter and indicates the start of temperature monitoring. When the finished diameter is reached, the paper layers of the annular temperature point (5) have a temperature 1.3 ° C higher than the directly adjacent paper layers. The end face of the roller (1) also shows a local point-like temperature point (6) which, compared to the ring-shaped temperature point (5), again has a temperature which is 0.5 ° C higher. The temperature gradation between the positions of the annular temperature point (5) and the local elevated temperature point (6) can be seen from FIGS. 4 and 5.

The perspective view of the roller (1) in Figure 2 shows the position of an annular Temperature point (5) in the edge area (R) of the roll (1). This edge area (R) on the raised surface or punctiform temperature points is observed through a hollow cylinder described in which the inner diameter = Outside diameter of the sleeve (2) of a wall thickness corresponds to the zone Z = 150 mm and one height (7) of 1/8 of the roll width (AB). Of the Hollow cylinder is with thin solid lines drawn, whereas the ring-shaped Temperature point (5) again by a thick dash-dotted line is shown.

The infrared camera (8) is at a distance A = 1.5 m, measured from the front of the roll, arranged. The measuring device of the infrared camera gives the coordinates of the place, d. H. the radial Distance from the sleeve surface when exceeded a temperature difference of 1 set here ° C to the memory (10). The Exchange facility (11) receives the transaction previously saved coordinates of the location and resolves the preferred one when the place is reached Role change. Determines the measuring device the infrared camera has smaller temperature differences, the change process is only complete Utilization of the wound web length respectively.

An alternative embodiment of the invention is shown in FIG. 3. The large roll (1 ') made of LWC paper with the dimensions AB = 3.2 m width, the outer diameter d _max = 1,250 mm and the sleeve diameter d _H = 150 mm is already up to Z '= 100 mm residual thickness unwound. The sheet-like temperature point (6 ') previously created at maximum roll mass has weakened only slightly in the course of the unwinding time due to the good insulating properties of paper and can also be detected in a larger area. The traversing, constantly measuring infrared camera (8 ') records the temperature profile across the roll width. An internal computer evaluates the temperature difference of the edges (R), which make up about 1/8 of the roll width, compared to the central area of the roll. If there is a set temperature difference, the computer transmits a control signal to the input of the changing device (11 '), which thus triggers the premature roll change. Here too, web breakers are successfully avoided by monitoring the temperature effects during unwinding.

Infrared temperature recordings on rotating LWC base papers are shown in FIGS. 4 and 5. The sleeve diameter (d _H ) and the zone (Z) are given in FIG. 5 for better orientation. Figure 4 shows the detail of a flat temperature point (6) on an enlarged scale. In Figure 5, the gray gradation of the normally colored infrared image clearly shows the local temperature point (6) occurring within an annular temperature point (5) in the core area of the roll (1). The temperature difference between the annular temperature point (5) and the local flat temperature point (6) is 0.5 ° C. The adjacent paper layers (12) have a temperature of approximately 31.9 ° C.

Claims (5)

1. Method of initiating an early reel change of a web of continuous material to be unwound from a spool, especially a paper web, characterized by the combination of the following features:

   during the time the reel comprises from 100 % to 60 % of its mass in the winding or unwinding process, a non-contact temperature measuring device is used to measure the temperature at the end face of the reel in a zone which is up to 150 mm away from the surface of the spool in a radial direction,

   at a detected temperature difference of ≥ 0.5 °C between point-form or two-dimensional thermal areas within the zone and the cooler adjacent regions, the radial distance from the spool surface is determined,

   the determined distance is stored for release of a signal that will initiate the reel change on reaching the distance.
2. Method according to Claim 1, characterized in that the temperature measurement is effected from both end faces of the reel.
3. Method of initiating a reel change of web of continuous material to be unwound from a spool, especially a paper web in web-fed printing presses, characterized by the combination of the following features:

   as the reel is being unwound in the region from 100 mm from the spool surface to the end of the web, a non-contact temperature measurement is carried out above the continuous web to be unwound in the edge region and in the middle region of the reel,

   by determining a temperature difference in the edge region of the reel compared with the middle region of > 0.5 °C, an early reel change is initiated by control signals produced by the temperature measuring device.
4. Method according to claim 3, characterized in that the temperature is measured by an infrared camera, equipped with a linear guide, traversing across the entire width of the reel.
5. Method according to any one of claims 1 to 4, characterized in that as temperature measuring device an infrared camera having a resolution accuracy of at least 0.2 °C is used.

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