Apparatus for treating a mineral fiber mat by detecting and removing localised defects, and corresponding method

Abstract

An apparatus for treating a mat of mineral fibers moving along a plane and a run direction, by detection and elimination of localized defects, includes a first transport member, a second transport member positioned after the first transport member in the run direction and separated therefrom in the run direction by a treatment zone, a device for detecting localized defects in the mat of mineral fibers, upstream of the treatment zone in the run direction, and in the treatment zone, a device for eliminating defects suitable for eliminating, in-line, a defect detected by the detection device by eliminating the portion of mat containing it.

Claims

1. An apparatus for treating a mat of mineral fibers moving along a plane and a run direction, by detection and elimination of localized defects, the apparatus comprising: a first member for transporting the mat of mineral fibers, a second member for transporting the mat of mineral fibers, the second transport member being positioned after the first transport member in the run direction and separated therefrom in said run direction by a treatment zone, a device for detecting localized defects in the mat of mineral fibers, located upstream of the treatment zone in the run direction, and the treatment zone, a device for eliminating defects suitable for eliminating, in-line, during transportation of the mat of fiber materials and without interruption of the transportation, a defect detected by the detection device by eliminating a portion of mat containing the defect.

2. The treatment apparatus as claimed in claim 1, wherein the detection device comprises at least one infrared radiation detection member.

3. The treatment apparatus as claimed in claim 1, wherein the elimination device is configured so that the portion of mat containing the defect is discharged in an elimination direction that passes through the thickness of the mat.

4. The treatment apparatus as claimed in claim 1, wherein the elimination device is configured so that the portion of the mat containing the defect is discharged in an elimination direction substantially parallel to the normal to the run plane of the mat.

5. The treatment apparatus as claimed in claim 1, wherein the elimination device comprises pressure or pulling means stressing a portion of the mat in an elimination direction.

6. The treatment apparatus as claimed in claim 5, wherein the application direction of the force exerted by the pressure or pulling means forms an angle of between 3° and 20°, with a direction normal to the run plane.

7. The treatment apparatus as claimed in claim 5, wherein the elimination device comprises a plurality of pressure or pulling members, oriented toward the treatment zone, and distributed in a lateral direction of the apparatus.

8. The treatment apparatus as claimed in claim 7, further comprising transmission means for transmitting to the elimination device information on the positioning of the detect in the lateral direction, and means for selective control of each pressure or pulling member as a function of said information.

9. The treatment apparatus as claimed in claim 1, wherein the distance between a first transport surface of the first transport member and a second transport surface of the second transport member is between 50 and 150 mm.

10. The treatment apparatus as claimed in claim 1, further comprising, in the treatment zone, at least one hatch suitable for being opened and closed in a controlled manner under the mat of mineral fibers.

11. A production line for producing a product based on mineral fibers, comprising: a fiberizing device for obtaining mineral fibers, a device for spraying a binder on said mineral fibers, for the formation of a mat of mineral fibers bound by a binder, and a binder crosslinking device, wherein the production line further comprises, between the spraying device and the binder crosslinking device, the treatment apparatus as claimed in claim 1.

12. The production line as claimed in claim 11, further comprising a device for cross-lapping the mat of fibers, between the treatment apparatus and the binder crosslinking device.

13. The production line as claimed in claim 11, further comprising a crimping device, between the treatment apparatus and the binder crosslinking device.

14. A process for treating a mat of mineral fibers moving along a plane and a run direction, by detection and elimination of localized defects by the apparatus as claimed in claim 1, the process comprising: transporting the mat of mineral fibers on a first transport member, then on a second transport member positioned after the first transport member and separated therefrom by a treatment zone in the run direction, detecting localized defects in the mal of mineral fibers, upstream of the treatment zone in the run direction, and in the treatment zone, eliminating, in-line, during transportation of the mat of fiber materials and without interruption of the transportation, a detected defect by eliminating a portion of mat containing the defect.

15. The treatment process as claimed in claim 14, wherein the portion of mat containing the defect is discharged in an elimination direction that passes through the thickness of the mat.

16. The treatment process as claimed in claim 14, wherein the mat of mineral fibers is a blanket of mineral fibers bound by an uncured binder.

17. The treatment process as claimed in claim 14, wherein the mat of mineral fibers is a mat of mineral fibers that are not bound by a binder.

18. A process for producing a product based on mineral fibers bound by a binder; comprising at least: the obtaining of mineral fibers, the spraying of a hinder on said mineral fibers, for the formation of a mat of mineral fibers bound by a binder, and the crosslinking of the binder, the process further comprising, between the spraying and the crosslinking of the binder, the treatment of the mat of mineral fibers by detection and elimination of localized defects as claimed in the treatment process of claim 14.

19. The treatment apparatus as claimed in claim 1, wherein the mineral fibers are glass fibers or rock fibers.

20. The treatment process as claimed in claim 14, wherein the mineral fibers are glass fibers or rock fibers.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates an apparatus for detecting and eliminating defects according to one embodiment of the present invention.

(2) FIG. 2 is a cross-sectional view along the plane II from FIG. 1.

(3) FIG. 3 illustrates the elimination of the portion of mat containing the defect M, with the treatment apparatus from FIGS. 1 and 2.

(4) FIG. 4 is a schematic representation of a production line for producing a product based on rock fibers, incorporating a treatment apparatus according to the invention.

DETAILED DESCRIPTION

(5) Illustrated in FIG. 1 is an apparatus 1 for treating a mat of mineral fibers 10, for example rock fibers, moving along a run direction X, by detection and elimination of localized defects M, in particular hot spots.

(6) The treatment apparatus 1 comprises: a first transport member 2 a second transport member 3, positioned after the first transport member 2 in the run direction X of the mat and separated therefrom in said direction X by a treatment zone 4, a device 5 for detecting localized defects in the mat of mineral fibers, located upstream of the treatment zone 4 in the run direction X, and in the treatment zone 4, a device 6 for eliminating defects M suitable for eliminating, in-line, the defects M detected by the detection device 5, by eliminating portions of the mat 10 containing them.

(7) The first and second transport members 2, 3 are here endless belts mounted around parallel axes, and driven by a motor. Each one comprises a main face respectively 2a, 3a, here an upper face, intended to come into contact with the mat of mineral fibers 10, and, more particularly, to support this mat of mineral fibers 10. These could, in an equivalent manner, be chain conveyors or roller table conveyors.

(8) The main faces 2a, 3a of the first and second conveyors are flat (although this is in no way limiting). They may be located in one and the same plane, as illustrated in FIGS. 1 to 3, or may optionally be inclined relative to one another.

(9) The first and second conveyors 2, 3 are spaced apart from one another, and separated, in the run direction X of the mat, by the treatment zone 4.

(10) The spacing between the first transport member and the second transport member, referenced d in FIG. 2, corresponds to the distance separating the main face 2a of the first conveyor 2 and the main face 3a of the second conveyor 3, in the run direction X. This spacing d is advantageously between 50 and 150 mm, preferably between 80 and 120 mm.

(11) The mat of fibers 10 is here a blanket of rock fibers bound with the aid of a binder that is not yet cured, and which blanket is intended for the manufacture of a board or roll of insulating wool (hereafter blanket).

(12) The mat 10 is then overall in the form of a continuous strip having two parallel main faces 10a, 10b, one of which (10b) is here in contact with the conveyors 2, 3. The mat has a width 1 and a thickness e, as illustrated in FIG. 1.

(13) The width 1 of the mat 10 is for example between 1000 and 4000 mm. Its thickness e is typically between 10 and 30 mm. The basis weight of the mat is for example between 300 and 500 g/m.sup.2.

(14) As explained above, at any point of the mat, a run plane is defined tangent to one of the main faces 10a, 10b thereof.

(15) Furthermore, locally a lateral direction Y is defined as the direction orthogonal to the run direction X of the mat and parallel to said run plane at the same point.

(16) The defect detection device 5 is, in the example, an infrared scanner located above the first conveyor 2, in other words upstream of the treatment zone 4.

(17) The scanner 5 is here static, and has a field of vision that scans at least the entire width 1 of the blanket in the lateral direction.

(18) Its field of vision is divided, in the lateral direction, into N sections S1, . . . , Sn, . . . , SN, preferentially of constant width (less than or equal to 1/N).

(19) The scanner 5 is suitable for re-establishing at any instant information characteristic or representative of the surface temperature of the mat in the aforementioned N sections of its field of vision. If the temperature measured in one or more of these sections at an instant t is considered to be above a predetermined threshold (for example 250° C. or 300° C. or 350° C.), corresponding information, comprising the X and Y coordinates of the section(s) in question (respectively in the run and lateral directions), is transmitted to the elimination device 6.

(20) The elimination device 6 is located downstream of the detection device 5, in the run direction X.

(21) More specifically, the elimination device 6 is located between the first and second transport members 2, 3.

(22) It comprises, in the example, N pressure members P1, . . . , Pn, . . . , PN, oriented toward the treatment zone 4, in other words toward the portion of the blanket 10 located in the space separating the first and second transport members 2, 3.

(23) In the particular example represented, the N pressure members P are compressed air nozzles, controlled by solenoid valves, as a function in particular of the information transmitted by the detection device 5.

(24) According to one advantageous arrangement, each nozzle is a so-called amplifying nozzle, i.e. entraining, in its operation, induced ambient air. The air consumption for a given blowing force is thus reduced. Therefore, this type of nozzle can be used at standard pressure of a compressed air network, typically between 5 and 6 bar, and does not necessitate the addition of a booster pump.

(25) By way of example, it has been observed that a nozzle, for which the blowing force (=maximum force exerted on a balance located 150 mm from the nozzle, during the blowing) is greater than or equal to 22 N, is particularly suitable for a fiber blanket having a basis weight of between 300 and 500 g/m.sup.2, spaced apart from the nozzle by a distance of between 50 and 200 mm, preferably between 80 and 100 mm.

(26) The pressure members P may be controlled selectively, as a function of the exact positioning of the defect M, in the lateral direction Y and in the run direction X. For example, a single nozzle may be actuated in order to eliminate a defect of small dimensions. In other cases, several nozzles adjacent to one another may be actuated simultaneously, in order to enlarge the width of material removed. Represented in FIG. 1 is a defect M extending over two sections Si and Sj treated by the scanner 5.

(27) The time t between the detection of the defect and the operation of the solenoid valves is set in advance, as a function of the run speed of the mat 10, so that the jet of air originating from the nozzles P encounters the portions of the mat containing the defect M at the moment they pass through the treatment zone 4, and so that these portions are discharged, under the effect of the pressure of the air.

(28) The actuating time of the nozzles P itself depends on the X coordinates of the detected defect. If this defect extends over a given length of the mat, in the run direction, the opening time of the solenoid valve(s) is consequently adjusted.

(29) Preferably, and as illustrated in greater detail in FIG. 2, the nozzles Pi are positioned so that the application direction of the blowing F is slightly inclined relative to the normal Z to the run plane.

(30) According to one advantageous arrangement, the blowing direction (direction of the pressure force exerted by each nozzle in the direction of the mat) forms an angle beta (β) of between 3 and 20°, preferably between 3 and 10°, more preferentially still between 4 and 6° (for example 5°) with the normal (Z) to the run plane of the mat. It has been observed that these angle values are advantageous since they make it possible to correctly cut the blanket without deforming it.

(31) Represented in FIG. 3 is the elimination of the portion of the mat 10 containing the defect M, by means of the nozzles Pi, Pj. The portion of mat, subjected to the pressure force exerted by the two nozzles, comes away from the mat and a localized hole is formed therein, that passes through the entire thickness of the mat, without damaging the adjacent portions. The defective mat portion passes between the conveyors and is recovered under the mat, for example in a recovery container, in order to be able to be treated (for example recycled after having been cooled, in the case of hot spots).

(32) The treatment apparatus 1 described above is given only by way of example and obviously does not limit the present invention.

(33) Thus, for example, the pressure means could be mechanical pressure means, typically in the form of N pressure fingers, that can be actuated selectively.

(34) Also, the elimination device may comprise pulling members, for example mechanical members of the extraction hook type or suction devices, instead of the aforementioned pressure members, or else a combination of these two types of members.

(35) Equally, the relative positioning of the first and second transport members may be different from that illustrated in FIGS. 1 to 3. Although, in most cases, the first and second transport members are located one after the other, they may, as a variant, be superimposed or else form an angle between them, for example a 90° angle.

(36) Finally, the treated mat may be a mat of mineral fibers which is free of binder. In this case, the mat is for example derived from a fiber blanket which is optionally previously de-carded, and forms a cluster of fibers without cohesion. Such a product may be used subsequently as blowing wool or to manufacture spraying wool.

(37) In this case, the mat may not move between the first and second transport members without a support element. This support element may then advantageously be formed by at least one hatch suitable for being opened and closed in a controlled manner under the mat of mineral fibers. It is understood that the hatch then forms a transport surface for the mat of mineral fibers, between the first and second transport members and in the direct continuity of these two transport members. When the hatch is open, the fibers located on the hatch fall, either solely under the effect of gravity (in the absence of pressure or pulling means), or under the combined effect of gravity and pressure or pulling means of the type described above, and are thus discharged.

(38) Obviously, in order to limit the amount of mat eliminated, the apparatus may advantageously comprise a plurality of hatches distributed in the width direction of the apparatus and the hatches may be actuated selectively (independently of one another), depending on the exact positioning of the defect detected.

(39) FIG. 4 schematically represents a production line 20 for producing a rock wool product, comprising a treatment apparatus according to the invention, in particular of the type described above in connection with FIGS. 1 and 2.

(40) The production line 20 comprises, from upstream to downstream, the following elements: a fiberizing device 22 for obtaining rock fibers, a device 24 (integrated into the fiberizing machine) for spraying binder on the rock fibers thus obtained, an apparatus 1 for treating the mat of fibers resulting from the fiberizing and spraying devices by detection and elimination of localized defects, of the type described above in connection with FIGS. 1 and 2, a cross-lapping device 28, and a binder crosslinking drying oven 30.

(41) As is known, the fiberizing device 22 comprises a series of four spinning wheels 23a, 23b, 23c, 23d arranged in a cascade, capable of rotating about substantially horizontal axes, in which the first wheel is the smallest 23a, the second wheel 23b is slightly larger, the third and fourth wheels 23c, 23d being very slightly larger and substantially of the same diameter.

(42) The first wheel 23a is supplied with molten material via a chute (not represented) and is essentially used for accelerating the material which is sent to the second wheel 23b, the flow of material decreasing at each wheel in proportion to the amount of fibers formed.

(43) Such a fiberizing device 22 generally comprises, in addition, means for generating, at the periphery of the spinning wheels, a stream of air substantially parallel to the rotational axes of the wheels, for the purpose of assisting the formation of the fibers by an effect of drawing and entraining the fibers in a direction perpendicular to their formation direction.

(44) A binder is sprayed onto the fibers by the spraying device 24 which is fed with binder solution by dedicated means. The mat of fibers 10 is then formed by the accumulation of the fibers on a receiving surface and conveyed in the line by a transport member, to the treatment apparatus 1, according to the invention, for the detection and optional elimination of localized defects, of hot spot type.

(45) It is then transported to the cross-lapping device 28.

(46) The cross-lapping device 28 is suitable for depositing the mineral fibers on a conveyor 32, in the form of several superimposed layers. The basis weight of the mat of fibers is thus increased, which makes it possible to obtain an insulation product with improved thermal and/or acoustic properties. For the sake of simplification, the conveyor 32 is represented in FIG. 4 in alignment with the conveying direction X, whereas it is in reality oriented perpendicularly along the direction Y.

(47) The cross-lapping device 28 is typically vertical. It comprises two belts 33, 34 with main surfaces 33a, 34a, intended to be in contact with the mineral fibers, which are parallel and face each other. The two belts 33, 34 move at the same speed and entrain the fibers between them, against their main faces. The two belts 33, 34 together oscillate about a horizontal axis parallel to their main surfaces, as illustrated by the arrow f in FIG. 1.

(48) The apparatus preferably also comprises a crimping device 26 also referred to as a crimping machine, positioned downstream of the cross-lapping device 28, and which makes it possible to increase the density and to orient the mineral fibers. The crimping machine 26 typically comprises six belts 36, 37, 38, 39, 40, 41 distributed as three successive pairs of belts positioned opposite. Each belt comprises a main surface, respectively 36a, 37a, 38a, 39a, 40a, 41a, intended to be in contact with the mineral fibers.

(49) The belts 36 and 37 of the first pair move at the same speed. The belts 38 and 39 of the second pair move at the same speed (different from the belts of the first pair). The belts 40 and 41 of the third pair move at the same speed (different from the belts of the first and second pairs).

(50) The crimping and cross-lapping operations both help to repair the hole made in the mat resulting from the elimination of a defective portion. Thus, the quality or the esthetics of the final product are not impacted by the treatment operation.

(51) The mat of fibers is then calibrated and transported to the drying oven 30, the temperature of which is for example close to 220° C. The temperature increase and the residence time of the fibrous mat in the drying oven 30 are adjusted to enable the curing of the binder and the elimination of the water. On leaving the drying oven 30, the mat of fibers typically undergoes, with the aid of cutting devices, a longitudinal cutting of its uneven edges, and optionally of the center, a cutting in a transverse direction and optionally in the thickness direction (splitting), so as to obtain blocks that will then be able to be stored in the form of boards or in a roll.