WO2024194365A1

WO2024194365A1 - Method and arrangement for providing complete rows of mineral fibre slabs

Info

Publication number: WO2024194365A1
Application number: PCT/EP2024/057471
Authority: WO
Inventors: Ralf Eklund
Original assignee: Paroc Group Oy
Priority date: 2023-03-21
Filing date: 2024-03-20
Publication date: 2024-09-26

Abstract

The invention relates to a method and arrangement for providing complete rows of mineral fibre slabs in a production process of mineral fibre slabs. In the method complete rows of mineral fibre slabs are transferred in the production process, wherein each row contains a predetermined number of mineral fibre slabs. Defective slabs are removed, whereby one or more incomplete rows of mineral fibre slabs are formed. The complete rows and the incomplete rows are transported along a common path in a first direction of travel on a conveyor, and one or more substitute slabs are inserted before the stacker into each incomplete row from at least one slab buffer. The incomplete rows are thus made into complete rows containing the predetermined number of mineral fibre slabs.

Description

METHOD AND ARRANGEMENT FOR PROVIDING COMPLETE ROWS OF

MINERAL FIBRE SLABS

The present invention relates to a method and an arrangement for providing complete rows of mineral fibre slabs according to the preambles of the enclosed independent claims.

Mineral fibres are manufactured by melting suitable mineral-rich raw materials, such as diabase, dolomite, limestone or slag in a melting furnace. The obtained melt is led to a fiberising apparatus, where it is formed into mineral fibres. Binder is applied to the fibres, which are collected to form a continuous mineral fibre web. After desired product forming steps the continuous mineral fibre web is then transferred through a curing oven, where the binder is cured. After the curing oven, the edges of the continuous web are usually trimmed off and the continuous web is cut transversally and longitudinally into mineral fibre slabs. The mineral fibre slabs are then stacked and packed.

The production process for mineral fibre slabs is continuous, which means that the continuous mineral fibre web as well as the cut mineral fibre slabs constantly advance through the successive processing steps from the collection of the fibres until the stacking of the slabs without pause or interruption. The fibre web and the mineral fibre slabs are transferred through the process by using series of conveyors or the like. The mineral fibre web is typically cut into rows of two, three or more adjacent mineral fibre slabs, which are transferred to the stacking. In stacking step, the rows of slabs are arranged or piled on top of each other to form two, three or more stacks of slabs, where the stacks contain a predetermined suitable number of slabs in preparation for packaging.

Before the stacking, the mineral fibre slabs are subjected to a quality control. Any imperfect or defective slabs must be disregarded from the process. However, if only one slab is removed from a row, the row becomes incomplete, i.e. it does not contain the right number of slabs, which causes problems in the stacking. Conventionally, if one slab in a row is deemed defective, the whole row is disregarded. This naturally increases the amount to of waste formed in the process and reduces the production efficiency.

EP 3615234 proposes a method and an apparatus for rejection of defective mineral wool slabs. The proposed solution comprises separating the non-complete rows and complete rows from each other to different conveyor paths. The non-complete rows are directed to a buffer table, where a complete row is assembled from the nondefective slabs. The method employs plurality of conveyor paths which should operate cooperatively. This increases the complexity and space requirements of the proposed system.

Consequently, there is still need for a simple, reliable and effective solution for providing complete rows of mineral fibre slabs in a production process of mineral fibre slabs.

An object of this invention is to minimise or possibly even eliminate the disadvantages existing in the prior art.

Another object of the present invention is to provide a simple, versatile and effective method for providing complete rows of mineral fibre slabs in a production process of mineral fibre slabs.

Yet another object of the present invention is to provide an arrangement which does not require much space, and which is simple to operate for providing complete rows of mineral fibre slabs in a production process of mineral fibre slabs.

These objects are attained with the invention having the characteristics presented below in the characterising parts of the independent claims. Some preferred embodiments of the invention are presented in the dependent claims.

The embodiments mentioned in this text relate, where applicable, to all aspects of the invention, both the method and the arrangement, even if this is not always separately mentioned. In a typical method according to the present invention for providing complete rows of mineral fibre slabs in a production process of mineral fibre slabs, the method comprises

- transferring complete rows of mineral fibre slabs in the production process, wherein each row contains a predetermined number of mineral fibre slabs,

- removing during the transfer defective slabs from the complete rows of mineral fibre slabs, whereby one or more incomplete rows of mineral fibre slabs are formed,

- transporting the complete rows and the incomplete rows of mineral fibre slabs along a common path in a first direction of travel on a conveyor, and

- inserting before the stacker one or more substitute slabs into each incomplete row from at least one slab buffer and making the incomplete rows of mineral fibre slabs into complete rows containing the predetermined number of mineral fibre slabs.

A typical arrangement according to the present invention for providing complete rows of mineral fibre slabs in a production process of mineral fibre slabs, where complete rows of mineral fibre slabs containing a predetermined number of mineral fibre slabs are transferred and defective slabs are removed from the complete rows of mineral fibre slabs, resulting in one or more incomplete rows of mineral fibre slabs, wherein the arrangement comprises

- a conveyor for transporting the complete rows and the incomplete rows of mineral fibre slabs in a first direction of travel along a common path,

- at least one slab buffer for substitute slabs, and

- at least one inserting means for inserting one or more substitute slabs from the slab buffer to the incomplete rows of slabs.

Now it has been surprisingly found that the complete rows of mineral fibre slabs can be simply and effectively obtained by transferring the complete and incomplete rows of mineral fibre slabs along a common path to the stacker, preferably from the cutting step to the stacking, while inserting substitute slabs from at least one slab buffer to the incomplete rows during the transfer to the stacker. There is no need to divert the paths of the complete and incomplete rows of mineral fibre slabs which saves significantly the space needed. The present invention is thus suitable for retrofitting to the existing production lines, as only space for inserting means and slab buffers is required. Furthermore, the present invention can be easily adopted for different production settings, with variable number of slabs in the row. The number of slab buffers needed for effective and fast insertion of substitute slabs can be adapted without difficulty to variable production settings. Furthermore, as the complete and incomplete rows of mineral fibre slabs are transported along the common path to the stacker, the adjustments and difficulties associated with operating several cooperating conveyor paths can be avoided.

In the production process of mineral fibre slabs, a mineral fibre web is cut longitudinally and transversely, whereby complete rows of mineral fibre slabs are formed. The continuous mineral fibre web is cut longitudinally and transversely in a direction of travel of the web by using cutting means. Such cutting means are known as such for a person skilled in the art. The original complete rows of mineral fibre slabs are thus created in a cutting step, where the continuous mineral fibre web is cut at least longitudinally and transversely, seen in the direction of the travel of the web. Typically in the cutting step the edges of the continuous mineral web are also trimmed off. The continuous web is thus transformed in the cutting step into original complete rows of essentially rectangular mineral fibre slabs, where each original complete row contains a predetermined number of mineral fibre slabs. The predetermined number of mineral fibre slabs in the complete row is preferably two to four or two to three slabs, but it may vary depending on the width of the production line and the desired dimensions of the final product. According one embodiment, the predetermined number of mineral fibre slabs in the complete row is two or three slabs. It is possible to cut the continuous mineral fibre web into a row comprising four or even five slabs, possibly even larger number of slabs. The original complete rows of mineral fibre slabs are then transferred with transfer means, such as conveyors or rotating rollers, further in the production process of mineral fibre slabs, towards the stacker.

After the cutting step, the production process of mineral fibre slabs comprises a defect detection step and a removal step of defective slabs. This means that during the transfer of the mineral fibre slabs from the cutting step to the stacker, defective slabs are detected by detection means and removed by removal means from the original complete rows of mineral fibre slabs. The reason for the removal may be visual defect, material defect, wrong size, wrong weight, incomplete curing or any other defect that renders the mineral fibre slab unsuitable for stacking, packaging and/or end use. The defective mineral fibre slab may be detected by any suitable manner in a detection step of the production process. The arrangement according to the invention may comprise detection means for detecting defective mineral fibre slabs and/or incomplete rows of mineral fibre slabs, such as a sensor or array of sensors. The detection means may comprise, for example, visual sensors, temperature sensors, camera(s), such as IR camera(s), and/or weighing means. The detection step of the defective mineral fibre slabs may be automatized, or it may be performed according to commands of operative personnel.

The defective mineral fibre slabs are removed by using removal means. In the removal step, the removal of defective mineral fibre slabs may be performed by any suitable removal means available, configured to remove the defective slabs. For example, the defective mineral fibre slabs may be removed by using a removal conveyor which comprises pivotable adjacent parallel conveyors. The number of adjacent parallel conveyors is equal to the number of mineral fibre slabs in a complete row, so that each slab in the row is conveyed and transferred by its own pivotable conveyor. If a defective slab is detected in the detecting step, a signal is generated either automatically or manually, and transferred to a control unit of the removal conveyor. The adjacent parallel conveyor carrying the defective slab is pivoted downwards or upwards, preferably downwards, whereby the defective mineral fibre slab is removed from the row of slabs. Alternatively, the removal means may comprise a slab grabber or the like, which can attach to the large surface of the defective slab and lift the defective slab away from the row of slabs. The removal of defective slab(s) produces one or more incomplete rows of original non-defective mineral fibre slabs. The incomplete row of these non-defective mineral fibre slabs thus comprises at least one empty space in the row from where the defective slab has been removed. After the removal step, where the defective mineral fibre slab(s) is/are removed, the complete rows and the incomplete rows of mineral fibre slabs are transported on a conveyor in a first direction of travel along a common path to the stacker. In the context of the present invention, the term “a conveyor” may comprise one conveyor or a series of several conveyors, arranged after each other. The term “common path” means that the complete rows and the incomplete rows of the mineral fibre slabs are transported after each other on the same conveyor(s) to the stacker. This means that the complete rows and the incomplete rows are transported after each other along a common path of conveyors to the stacker. In order to make the incomplete rows of mineral fibre slabs into complete rows, a required number of substitute slabs are inserted into each incomplete row from at least one slab buffer before the stacker. The arrangement according to the present invention thus comprises at least one slab buffer for substitute slabs, located before the stacker.

Preferably the substitute slabs are inserted one-by-one into the uncomplete row(s).

It is possible that the arrangement comprises several slab buffers, for example two or three slab buffers, arranged successively along the conveyor in the first direction to travel. By using several slab buffers it is possible to insert several substitute slabs, one-by-one, into one incomplete row. Use of several slab buffers may also reduce the size required for each slab buffer, which is advantageous especially when the arrangement according to the invention is retrofitted to an existing production line where the available space may be limited.

According to one embodiment of the invention at least one slab buffer is located or arranged next to the conveyor, where the complete and incomplete rows are transferred, seen in the first direction of travel. The slab buffer may be a buffer table having a capacity for at least one substitute slab, but it can have capacity for two or three slabs. The slab buffer may even be arranged to hold a stack of substitute slabs, wherein the top slab of the stack is then used for insertion to the empty space in the incomplete row. In case the arrangement comprises more than one slab buffer, the slab buffers can be arranged next to the conveyor, on opposite sides of the conveyor. In this way insertion of substitute slabs can be made faster, especially for creating complete rows with three or more slabs. It is possible that the slab buffers are arranged alternately on opposite sides of the conveyor. It is also possible that all slab buffers are arranged on the same side of the conveyor.

The arrangement according to the present invention comprises at least one inserting means, located before the stacker, for inserting one or more substitute slabs from the slab buffer to the incomplete row of slabs. The substitute slab may be inserted to the incomplete row in any suitable manner and by using any suitable inserting means. For example, the substitute slab can be lifted from the slab buffer into the empty space of the incomplete row by using a lifting means or a slab grabber that can attach to the large surface of the substitute slab and lift it into the incomplete row. According to a preferable embodiment the substitute slab(s) may be inserted into the incomplete row by a transversal feeder or transversal pusher, which pushes the substitute slab(s) transversely to the first direction of travel. The inserting means thus preferably comprise a transversal feeder or pusher, which is arranged to move transversely to the first direction of travel and push substitute slabs transversally onto the conveyor. The transversal feeder is thus arranged to move in a second direction, which is transverse to the first direction of travel.

The substitute slab can be directly inserted to the empty space in an incomplete row, or the substitute slab may push the original non-defective slab of the incomplete row to fill in the empty space, wherein the substitute slab takes the place of the original non-defective slab in the row.

Typically each slab buffer is associated with one inserting means. However, it is possible that two or more inserting means are associated with one slab buffer, especially when the inserting means, such as slab grabbers, lift the substitute slabs from the slab buffer to the incomplete row. The substitute slabs in the slab buffer may be obtained, and the slab buffer created, by removing incomplete row(s) of mineral fibre slabs from the conveyor to the slab buffer. This means that the inserting means can be arranged to remove one or more incomplete rows of mineral fibre slabs from the conveyor to the slab buffer, where the removed slabs become substitute slabs for the following incomplete row. For example, when the slab buffer is empty, i.e. no substitute slabs are located in the slab buffer, the following incomplete row on the conveyor may be removed from the conveyor and be transferred to slab buffer. Thus the correct slab(s) of the incomplete row become substitute slab(s) that can be inserted to the following incomplete row. According to another embodiment of the invention, the slab buffer may be independently created, for example from previously made correct mineral fibre slabs can be used as substitute slabs.

According to one embodiment, the inserting means can be configured to receive a signal when at least one defective mineral fibre slab is removed in the removal step and the incomplete row of mineral fibre slabs is formed. The inserting means may comprise a control unit which is configured to receive a signal each time the adjacent parallel conveyor of the removal conveyor is pivoted for removal of a defective mineral fibre slab. The generated signal may not only contain information about the formation of the incomplete row but also information about the location of the formed empty space within the incomplete row. In case the arrangement comprises more than one inserting means, they may all be communicatively connected with each other. For example, all inserting means may be connected to a central control unit, which is configured to calculate the optimal pattern for inserting substitute slabs into the incomplete rows, based on signal(s) received from the removal conveyor. According to one preferable embodiment, the arrangement comprises two slab buffers and two inserting means, which are communicatively connected with each other.

According to one embodiment of the invention, the arrangement comprises a stacking table, which is arranged after the conveyor transferring the complete and the incomplete rows, and between a stacker and the slab buffer, seen in the first direction of travel. The complete rows and the incomplete rows of mineral fibre slabs are transported along the common path to the stacking table, located between a stacker and the slab buffer, seen in the first direction of travel. The substitute slabs are inserted into the incomplete rows on the stacking table, before the row is transported to the stacker, by using any suitable inserting means as described above. According to one preferable embodiment, one or more substitute slabs is/are inserted into the incomplete row of mineral fibre slabs on the stacking table by the transversal feeder to form the complete row of mineral fibre slabs, which is then pushed by the transversal feeder to the stacker. The transversal feeder can thus be used not only to insert the substitute slab(s) into the incomplete row, but also for transferring the complete rows to the stacker.

Some embodiments of the invention are described in the accompanying schematical figures, where

Fig. 1 shows one embodiment of the present invention, seen above;

Fig. 2 shows one embodiment of a slab buffer and inserting means, seen in the first direction of travel;

Fig. 3 shows one embodiment of the present invention with two slab buffers, seen above; and

Fig. 4 shows yet another embodiment of the invention, seen above.

Figure 1 shows one embodiment of the present invention, seen above. A continuous mineral fibre web 1 is cut along longitudinal cut lines T and transversal cut lines 1 ” with cutting means 11 , 11 ’, schematically shown. The direction of travel of the mineral fibre web 1 is indicated in Figure 1 with arrow A. Cutting of the mineral fibre web 1 creates original complete rows 2, 2’ of mineral fibre slabs. In the embodiment depicted in Figure 1 , each complete row comprises three mineral fibre slabs. In original row 2, two of the slabs contain defects, indicated with a dot. The possible defects in the mineral fibre slabs are detected with detection means 3. If any defects are detected, the defective slab is removed by using removal means (not shown), and incomplete rows 4, 4’ of mineral fibre slabs are formed. The complete rows 2, 2’, 5 and the incomplete rows 4, 4’ of mineral fibre slabs are transported along a common path on the same conveyor in the direction of travel A.

A substitute slab 6 is inserted into the incomplete row 4’ from a slab buffer 7 by using inserting means 8 which pushes the substitute slab 6 transversely to the first direction of travel A, and makes the incomplete row 4’ of mineral fibre slabs into a complete row. The following substitute slab 6’ located in the slab buffer 7 is indicated with dash lines. The reciprocating transversal movement of the inserting means 8 in a second direction, which is transverse to the first direction, is indicated with double- ended arrow.

Figure 2 shows one embodiment of a slab buffer and inserting means, seen in the first direction of travel. An incomplete row 24 comprising one mineral fibre slab 100 is transported on a conveyor 101 . A slab buffer 27 comprising a stack of substitute slabs 26, 26’ is arranged next to the conveyor 101 . Transversal feeder 28 functions as insertion means and is arranged to push substitute slab 26” from the stack transversally onto the conveyor 101 , whereby a complete row comprising two mineral fibre slabs 100, 26” is formed.

Figure 3 shows one embodiment of the present invention with two slab buffers, seen from above. In the depicted embodiment the direction of travel of the slab rows is indicated with arrow A and the complete row 32 of mineral fibre slabs comprises three adjacent slabs. Two slab buffers 37, 37’ with transversal feeders 38, 38’ as the insertion means are arranged next to the conveyor 101 . The slab buffers 37, 37’ are arranged on opposite sides of the conveyor 101 , seen in direction of travel A. The transversal feeders 38, 38’ insert substitute slabs 36, 36’ to the incomplete rows 34, 34’ of mineral fibre slabs, wherein complete rows of slabs are formed.

Figure 4 shows a further embodiment of the invention, seen from above. The direction of travel of the slabs is indicated with arrow A. A slab buffer 37 is arranged next to a stacking table 40, which is arranged after the conveyor 101 . The stacking table 40 is arranged between a stacker 41 and the slab buffer 37. A transversal feeder 48 functions as the insertion means and as a pusher for transferring the complete rows from the stacking table 40 to the stacker 41. In case an incomplete row arrives to the stacking table 40, the transversal feeder 48 is arranged first to insert a substitute slab 46 to the incomplete row and then to push the completed row to the stacker 41 to form two stacks 42, 42’ of mineral fibre slabs.

Even if the invention was described with reference to what at present seems to be the most practical and preferred embodiments, it is appreciated that the invention shall not be limited to the embodiments described above, but the invention is intended to cover also different modifications and equivalent technical solutions within the scope of the enclosed claims.

Claims

1. A method for providing complete rows of mineral fibre slabs in a production process of mineral fibre slabs, the method comprising

- removing during the transfer defective slabs from the complete rows of mineral fibre slabs, whereby one or more incomplete rows of mineral fibre slabs are formed, characterised in

- transporting the complete rows and the incomplete rows of mineral fibre slabs along a common path on a conveyor in a first direction of travel , and

2. The method according to claim 1 , characterised in that at least one slab buffer is located next to the conveyor, seen in the first direction of travel, and the substitute slab(s) is/are inserted into the incomplete row by a transversal feeder, which pushes the substitute slab(s) transversely to the first direction of travel.

3. The method according to claim 1 or 2, characterised in that at least one slab buffer is created by removing incomplete row(s) of mineral fibre slabs from the conveyor to the slab buffer.

4. The method according to claim 1 , 2 or 3, characterised in that the complete rows and the incomplete rows of mineral fibre slabs are transported along the common path to a stacking table located between a stacker and the slab buffer, seen in the first direction of travel.

5. The method according to claim 4, characterised in that one or more substitute slabs is/are inserted into the incomplete row of mineral fibre slabs on the stacking table by the transversal feeder to form the complete row of mineral fibre slabs, which is then pushed by the transversal feeder to the stacker.

6. The method according to any of preceding claims 1 - 5, characterised in that the predetermined number of mineral fibre slabs in the complete row is two or three slabs.

7. An arrangement for providing complete rows of mineral fibre slabs for a production process of mineral fibre slabs, where complete rows of mineral fibre slabs containing a predetermined number of mineral fibre slabs are transferred, wherein the arrangement comprises

- removal means configured to remove defective slabs from the complete rows of mineral fibre slabs, resulting in one or more incomplete rows of mineral fibre slabs,

- at least one slab buffer for substitute slabs, and

8. The arrangement according to claim 7, characterised in that at least one slab buffer is arranged next to the conveyor, seen in the first direction of travel.

9. The arrangement according to claim 8, characterised in that the inserting means comprise a transversal feeder, which is arranged to push substitute slabs transversally onto the conveyor.

10. The arrangement according to claim 7, 8 or 9, characterised in that the inserting means are arranged to remove one or more incomplete rows of mineral fibre slabs from the conveyor to the slab buffer.

11 . The arrangement according to any of claims 7 - 10, characterised in that the arrangement comprises a stacking table, which is arranged after the conveyor and between a stacker and the slab buffer, seen in the first direction of travel.

12. The arrangement according to any of preceding claims 7 - 11 , characterised in that the slab buffer is a buffer table having a capacity for at least one substitute slab.

13. The arrangement according to any of preceding claims 7 - 12, characterised in that the arrangement comprises detection means for detecting defective mineral fibre slabs and/or incomplete rows of mineral fibre slabs.

14. The arrangement according to any of preceding claims 7 - 13, characterised in that the inserting means are configured to receive a signal when at least one defective slab is removed and the incomplete row of mineral fibre slabs is formed.

15. The arrangement according to any of preceding claims 7 - 14, characterised in that the arrangement comprises two slab buffers and two inserting means, which are communicatively connected with each other.