EP1502717B1 - Method for removing waste material from a blank made of mineral fibres - Google Patents

Abstract

The waste (6) is produce by e.g. punching out of mineral fiber felts (1), which are transported horizontally on a conveyor (3,4). A crossbar pref. located above the conveyor has compressed air nozzles (8) positioned along it dependent upon the positions of the waste. The nozzles generate an impulse jet at precisely the moment, in which the waste passes under the nozzle. The nozzle is connected to a compressed air tank and is computer-controlled dependent upon the position of the waste in direction of movement of the mineral fiber felt, and the traveling speed of the conveyor. Impulse width/period of the pressure jets is limited to max. 0,1s, pref. less than 0,05s.

Description

The invention relates to a method for removing the non-benefit from the use of a mineral fiber product according to the preamble of claim 1.

In the production of mineral fiber products such as plates or in particular felts for some applications there is the need to provide already in the course of the production of the mineral fiber product breakthroughs for later installation. This is particularly the case when the mineral fiber product is processed industrially, that is to be installed in large quantities in devices or grown on them, and precipitates a processing in place as a result of industrial processing. An example of this is for example needled felt for lining the furnace muffle of herds. The already pre-fabricated on the product breakthroughs are arranged according to location, shape and size so that in the case of installation in the recesses of the insulating layer male components such as cables or the like can be added without any post-fabrication to the insulation layer.

To produce such breakthroughs, the material to be removed is first separated from the residual material, for example by a cutting process such as a punching operation. In a punching of openings on a thin, solid material such as a metal sheet, the separation by the punching process as such is sufficient, and the separated material usually falls out of the breakthrough easily by gravity, so that it is created directly by the punching process , However, for mineral fiber products as thick as several centimeters, even after the separation operation, the adhesion of the waste material to the residual material due to the rough and large fiber surface is so high that the actual removal of the waste material requires a mechanical ejection process. After the separation process, the fiber product is thus provided with cuts, however, it still contains the waste, which is referred to as "non-use" in technical terms, while the remaining material ultimately to be used is referred to as "benefit". In the context of the present invention, it is therefore a matter of removing the non-benefit already defined by a corresponding separation process from the use of the mineral fiber product.

For this purpose, it has hitherto been necessary to position workers along the conveying member for the mineral fiber product in the conveying direction after the separating station, which individually eject the non-uses by hand through the material of the use. This is extremely labor-intensive and also represents a monotonous work. If the product is to be provided with a plurality of openings, so either a corresponding number of additional labor along the line formed by the conveying member to provide, or it must reduce the production speed of the conveying member which is economically disadvantageous and can lead to production bottlenecks.

One could think of disposing a vacuum chamber in a disposal zone for the benefits below the mineral fiber product, which draws the non-benefit out of the benefit. However, the suction force acting on the respective non-use is proportional to the area of the non-benefit. For the disposal of small-area non-use, which serve as the passage of a small diameter pipe, so high vacuum would be required that the fiber product would be damaged; Moreover, with regard to the system-inherent leaks, very high blower outputs would be required. In any case, in the case of a plurality of non-use, the effective negative pressure would collapse when disposing of the first non-use, since false air would be sucked through the opening formed, so that disposal of the remaining non-use would no longer be guaranteed either way.

One could also think of using an overpressure chamber placed above the product instead of a vacuum chamber mounted under the product. Here, however, the conditions would be the opposite.

One could further think of avoiding the problem of the collapse of the pressure difference on removal of the first non-use by using a dynamic overpressure by an air flow instead of a static overpressure above the fiber product. Thus, one could provide over the entire width of the conveying member reaching slot nozzle, which acts on a corresponding line of the continuous mineral fiber product with high dynamic pressure, so as to blow under this line continuous non-use of the benefit. Again, however, it would remain with the problem that the ejection force acting on a non-utility is proportional to its area. However, small-area non-utility require a particularly large ejection force to overcome the acting along the scope of non-use high frictional forces on the benefits even without noticeable deformation of the non-use in the ejection process. The provision of a dynamic overpressure for the safe blowing out of even small-area use would, apart from the high energy consumption, inevitably lead to such a local pressure load also of the benefit that damage to the fiber material would be unavoidable.

From the GB 696,398 is a method for removing a Nichtnutzens from the use of a product, here a carton, known, in which the non-use is defined by a separation process and the product thus pretreated is transported lying on a conveyor organ. In this case, compressed air nozzles are arranged above the conveying member on a traverse whose position along the traverse and thus transversely to the conveying direction of the product in a desired position is adjustable and fixable. Further, a pulse burst of the compressed air nozzle is generated when the targeted non-use passes under the compressed air nozzle. The present invention is based on the initially discussed method as the closest prior art, since this refers to the processing of serving as an insulating mineral fiber products.

The invention has for its object to provide a method for removing the non-benefit of the benefits of mineral fiber products, which avoids manual work, but it ensures a reliable removal of all non-use without risk of damage to the benefit and without excessive energy consumption.

The solution of this object is achieved by the features of claim 1.

This results in a targeted air pressure surge for each non-benefit to be removed, which blows the non-benefit of the surrounding benefits, without affecting the surrounding benefits or even affect or damage. The targeted control of the desired impact point for the air pressure surge takes place in the surface of the mineral fiber product two-dimensional: the one dimension transverse to the conveying direction is set by a mechanical pre-adjustment and fixing the compressed air nozzle at that point above the product, which corresponds to the position of the targeted Nichtnutzens in the width direction of the product. The control in the conveying direction is carried out by a temporal control such that the compressed air pulse is generated at exactly the time at which the targeted non-use passes under the compressed air nozzle. In the case of a small area, substantially symmetrical non-use of the impulse pulse is as accurate as possible in the center of the non-use, to drive out the non-use, without causing tilting. In the case of larger and irregular shaped non-use, the optimum position of the impulse burst (s) will be determined empirically. In the case of a spectacle-shaped non-use, for example, a pulse impulse would expediently be directed to the respective spectacle eye.

Furthermore, the temporal pulse width or pulse duration of the compressed air blasts according to the invention is limited to a maximum of 0.1 s. Primarily used for the blow-out process is the impulse peak, which occurs with a duration in the range of a thousandth of a second. A narrow limitation of the pulse duration on both sides of the pulse peak allows a concentration of the available pulse energy on the pulse peak and thus a high pulse force at the exact desired time.

This is already out of the JP 07-132496 A a method has been known in which an impulse pulse of compressed air nozzles which can be moved over the product in two directions is used in order to completely remove any non-use after punching out of the use; However, the machined material is designed like a sheet and, for example, a cardboard or corrugated board, so that it is in a thin and solid shape. Therefore, there are problems with the adhesion of the waste material to the residual material due to the rough and large fiber surface of mineral fiber products.

According to claim 2, the activation of a connected to a compressed air reservoir tank compressed air nozzle takes place with such a lead time, which corresponds to the delay of the pulse exit from the nozzle opening with respect to the pulse triggering. Such a compressed air reservoir tank upstream of the compressed air nozzle is advantageously used because it provides a sufficient amount of air to achieve a large impulse force. The delay between pulse initiation and pulse output can be calculated accurately, so that the pulse emerges with great local accuracy to meet the non-use exactly at a desired location.

Since the mineral fiber product is conveyed on the conveyor at a speed of, for example, 0.3 m / s, the nozzle opening covers a product length of 30 mm in one tenth of a second and 3 mm in one hundredth of a second. In order to apply a pressure pulse in the middle of, for example, 6 mm in diameter measuring small-area non-use, thus accuracy of the timing in the range of a thousandths of seconds is required. For this purpose, the timing of the pulse bursts according to claim 3 is preferably computer controlled in dependence on the position of the non-use in the transport direction of the mineral fiber product and the running speed of the conveying member. In this way, the lead time of the control of the nozzle can be set as arbitrarily accurate such that the impulse pulse is limited in time and hits the product surface at the exact desired time.

Appropriately, according to claim 4, the temporal pulse width or pulse duration is limited to less than 0.05 s.

Another problem associated with the production of such products, for example, for the insulation of stove muffles is that the fast-arriving benefits must be stacked and packaged following the removal of the non-benefits. Also, this stacking in terms of pre-stacking for the subsequent packaging of the stack must currently be carried out by hand. Although stacking machines for mineral fiber boards or felt are available in the state of the art, these are large, bulky stationary installations which require very large investments and can not be used economically in the case of limited quantities of a specific product.

When processing laminated felts or plates with, in particular, top-side lamination foil, it would be possible to use a suction gripper for pre-stacking, which acts on the lamination foil with suction bodies and thus lifts the fiber product. However, this is not possible with unlaminated products.

In this respect, another sub-task of the invention is to avoid the manual labor in pre-stacking the products for the packaging at the end of the line even in the case of producing unbacked mineral fiber products.

According to the invention according to claim 5, a flow gripper is placed on top of the mineral fiber product, which produces such a pressure difference .DELTA.p between the underside of the mineral fiber product and its top, which, multiplied by the effective area of the mineral fiber product, exceeds the weight of the mineral fiber product.

In this way, an air flow is thus generated through the mineral fiber product, wherein the pressure drop due to the flow resistance of the mineral fiber product is used to generate an upward pressure force which is large enough to exceed the weight of the mineral fiber product, so that this - can be raised without using any stationary suction. In this way, plate to plate or felt can be stacked by felt and avoid the manual work at this point.

In order to be able to receive even the lowermost flat on a conveyor belt of the conveyor organ resting fiberboard or the like in this way, the conveyor belt according to claim 6, for example, through air permeable perforations formed and / or the mineral fiber product relative to the surface of the conveyor belt mounted.

To generate the most uniform air flow in the flow gripper inside is according to claim 7 whose lower surface, for example by uniformly distributed perforations designed permeable to air. In this way, a substantially uniform lifting force is generated across the surface of the mineral fiber product.

According to claim 8, the area of the underside of the flow gripper preferably corresponds substantially to the area of the mineral fiber product. In this way, the entire surface of the mineral fiber product is used to generate the lifting force, so that the lifting of the mineral fiber product can be done with minimal Δp. Also, the effect of possible breakthroughs left behind by non-use is minimized here in the sense of producing incorrect air, since the area fraction of non-use compared to the benefit is generally very small. On the other hand, if the area of the flow gripper is smaller than the surface of the product, an unfavorably located large-area non-use could lead to considerable erroneous air flow and thus disturbance of the pressure build-up.

Fig. 1

eine schaubildliche Darstellung eines Förderorgans mit einem darauf angeordneten Nadelfilz mit Nutzen und Nichtnutzen und mit schematischer Darstellung der erfindungsgemäßen Entfernung der Nichtnutzen,

Fig. 2

eine Draufsicht auf einen Verbund von zwölf Nadelfilzelementen mit Nichtnutzen und schematischer Veranschaulichung der Positionen der Druckluftdüsen gemäß einer beispielhaften praktischen Ausführungsform,

Fig. 3

eine perspektische Darstellung der Anordnung einer Druckluftdüse,

Fig. 4

eine vergrößerte schematische Schnittdarstellung durch ein Mineralfaserprodukt mit kleinflächigem Nichtnutzen, und

Fig. 5

eine schematische Darstellung eines Strömungsgreifers zur Stapelung von Filzprodukten.

Further details, features and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the drawing. It shows:

Fig. 1

a perspective view of a conveyor organ with a needle felt arranged thereon with benefits and non-benefits and with a schematic representation of the removal of non-use according to the invention,

Fig. 2

12 shows a plan view of a composite of twelve non-functional needled needle elements and a schematic illustration of the positions of the compressed-air nozzles according to an exemplary practical embodiment,

Fig. 3

a perspective view of the arrangement of a compressed air nozzle,

Fig. 4

an enlarged schematic sectional view of a mineral fiber product with small area non-use, and

Fig. 5

a schematic representation of a flow gripper for stacking felt products.

As can be seen from FIG. 1, a mineral fiber product, denoted overall by 1, in the example of an unbacked needle felt, rests on a conveying member 2. The conveying member 2 consists of a plurality of successively connected conveyor belts 3 and 4. The mineral fiber product 1 consists of the so-called benefit 5 and one or more non-use 6, which have been separated from the utility 5 to form breakthroughs in a previous separation process.

The non-benefits 6 are manually pushed out of use 5 in current practice. With a relatively large area non-use 6, this is possible with little effort, since the non-use 6 bends at punctual load by a finger and can be disposed of deforming. In the case of small-area non-use 6, on the other hand, the situation is more similar to that of a cork in the bottleneck: as can be seen in the enlarged view in Fig. 4, a bending deformation of the non-use 6 in such a case is practically impossible. The non-use 6 is located along the dividing line designated 7 on the benefit, wherein the two fiber surfaces have considerable frictional resistance. This frictional resistance must be overcome by pressure with the finger on the non-use 6 so that it can be disposed of, as illustrated in phantom in Fig. 1. As can readily be seen, extremely high static air pressure differences at the top and bottom of the fiber product 1 would be required to squeeze out a small area non-utility 6 from the utility 5 by such a pressure differential. Such high pressures would damage the fiber material's utility as well.

According to the present invention is therefore intended to use a compressed air nozzle 8, which is arranged in the example case above the mineral fiber product 1 at a small distance above the surface thereof. The compressed air nozzle 8 is in the Operated intermittently, as they at exactly the time at which the non-use 6 is conveyed through in the mineral fiber product 1 under the compressed air nozzle 8, generates a strong compressed air pulse, which impinges exclusively and substantially symmetrically on the non-use 6 and this in running conveyor 2 from removed the benefit 5. The disposal point is chosen so that below the fiber product 1 free space for a discharge of non-use 6 is available.

In Fig. 2, a realistic work situation is shown in plan view. Twelve needle felting elements as mineral fiber products 1 lie on the conveying member 2, not shown in detail, wherein each three needle felting elements are arranged adjacent to each other with their longitudinal sides in the width direction of the conveying member 2. This composite of twelve needle felting elements has been produced in this arrangement in a punching station such that on the one hand the dividing lines between the needle felting elements and on the other hand at the same time six non-use 6 per needle felting element have been generated to produce corresponding openings in the needle felts. As the dimensioning in the width direction and in the conveying direction shows, each non-use 6 is determined by two dimensions: by its position in the width direction (transverse to the conveying direction) and by its distance from the front edge of the composite.

Above the conveying member 2, two rows of 16 compressed air nozzles 8 are arranged. These are adjusted in the width direction and found that one of the compressed air nozzles 8 is located exactly on the line lying in the conveying direction, which passes through one of the non-use 6. The non-use 6 thus all run exactly and in the case of an example centrally under the nozzle opening of a compressed-air nozzle 8 therethrough.

More difficult is the timing of the compressed-air surge such that a tightly limited compressed air surge or compressed air pulse is generated at exactly the time at which the targeted non-use 6 passes under its associated compressed air nozzle 8. This timing is appropriate computer controlled such that the current position of the respective fiber product 1 detected is in the example of Fig. 2, as the leading edge of the composite, and over the known speed of the conveying member that time is calculated, which the targeted non-use 6 needed to reach the position of the associated compressed air nozzle 8.

Appropriately, this is done with a relatively close to the compressed air nozzle 8 arranged, not shown compressed air reservoir, which is constantly maintained at a desired pressure and valve-controlled to produce a compressed air surge for a short period of time to the compressed air hose of the compressed air nozzle 8 is opened. In this case, the filling of the compressed air hose requires a certain period of time or requires the pressure front coming from the compressed air storage tank a certain time to pass through the compressed air hose and the body of the compressed air nozzle 8 and reach the nozzle orifice and nozzle opening and the surface of the fiber product 1. To precede this period of time, the computer has to open the output valve of the compressed air storage tank, so as to arrive at a right moment over the targeted non-use 6 taking into account this delay to a generation of the compressed air surge.

In this way, a high-energy compressed air pulse of low pulse duration and high pulse peak can be generated, which, if it hits as centrally as possible on the non-use 6 of the form shown by way of example, suddenly ejects the non-use 6 without damaging tilting from the use 5.

In Fig. 3, an arrangement of such a compressed air nozzle 8 is schematically illustrated. The compressed air nozzle 8 has a lower nozzle opening 9 and a nozzle body 10, which is arranged for the most part in a nozzle holder 11. At the top of the nozzle body 10 and the nozzle holder 11, a compressed air connection 12 is provided, to which a compressed air hose for connection to a compressed air reservoir is connected for operation.

The nozzle holder 11 engages around a traverse 13, of which only a short section can be seen in FIG. The traverse 13 has a scale 14, which allows a pointer 15 on the nozzle holder 11 an exact adjustment of the lateral position in the width direction of the conveying member such that the compressed air nozzle 8 shows with its nozzle opening 9 exactly on a line which passes through a non-use 6 (see Fig. 2). To determine this position, a clamping screw 16 is provided, as is customary for such purposes.

With the described arrangement safe disposal of non-use 6 from the benefit 5 is guaranteed for the first time without manual work. In this case, the removal of the non-use 6 is no limitation of the production speed of the conveying member 2, since the compressed-air nozzles 8 can work as fast as desired in the frame in question here. At a single, substantially linear position of the production line all non-use 6 can thus be disposed of at high speed, which previously would have been required for the same power a variety of workers along the production line. This also contributes to the shortening of the production line.

However, manual labor is still required to pre-stack the mineral fiber products 1 at the end of the conveyor organ 2 and pack.

To avoid manual work in the pre-stacking according to the invention in Fig. 5 schematically illustrated flow gripper 21 is provided. This consists of a box-shaped body 22, a suction air connection 23 and a bottom or bottom surface 24, which is permeable to air, for example, heavily perforated. The flow gripper 21 is so movably mounted in a manner not shown, but known per se, that it is movable up and down and laterally to be able to pre-stack recorded fiber products 1.

The conveyor belt 4 in the region of the flow gripper 21 is either likewise designed to be permeable to air, for example perforated, or else with distance elevations provided, which bring the underside of the fiber product 1 at a distance from the surface of the conveyor belt 4. In this way, the negative pressure generated by the suction port 23 in the flow gripper 21 through the conveyor belt 4 and the fiber product 1 and the lower surface 24 through an air flow generated, as illustrated in Fig. 5 by arrows 25. In this case, both the conveyor belt 4 and the lower surface 24 is formed in the sense of the lowest possible air resistance, so that the substantial part of the pressure drop of the flow according to the arrows 25 by the increased flow resistance of the mineral fiber product 1 takes place. In this way, at the lower side of the mineral fiber product 1, an air pressure p1 greater than the air pressure p2 at the top of the mineral fiber product 1 results after the flow has passed through the flow resistance mineral fiber product 1. If A is the surface of the lower surface or underside 24 of the flow gripper 21, the result is a lifting force acting on the mineral fiber product 1 in the amount of A x Δp. If this is kept higher by setting a corresponding flow rate than the weight G of the mineral fiber product 1, the fiber product 1 is lifted and fixed to the lower surface 24 of the flow gripper 21. In this position, the mineral fiber product 1 can be moved up and to the side so as to form a stack. In contrast to conventional vacuum grippers with static negative pressure on suction cups or the like, non-laminated fiber material can also be lifted and manipulated with such a flow gripper 21.

Breakthroughs contained in the mineral fiber product 1, from which the non-use 6 was previously removed, naturally reduce the overall flow resistance of the mineral fiber product 1. Should these breakthroughs be extensive, and should the flow gripper 21 continue to attack unfavorably in the region of such large-area non-use 6 with a relatively small area A, the generation of a sufficient lifting force becomes difficult. Therefore, it is preferable that the area A of the lower surface 24 be kept in approximate conformity with the area of the mineral fiber product 1. Seen on the total surface of Mineralfaserrproduktes the surface portion of the non-use 6 and the breakthroughs formed thereby is relatively low, otherwise too much material in the form of non-use 6 would have to be disposed of and therefore to a multi-part training of the mineral fiber product 1 avoided. In this context, although the surface areas occupied by apertures do not participate in the generation of the lifting effect, however, the lifting effect in the area of the benefit 5 is sufficient, since the breakthroughs also correspondingly reduce the weight of the fiber product 1.

In this way, the manual work is limited to the pure packaging of pre-stacked mineral fiber products 1 in the end of the production line and so allows the automatic non-use disposal enabled high production speed in this area by eliminating manual labor.

Claims (8)

1. A method for removing discards (6) from the useful part (5) of a mineral fiber product (1) which serves as an insulation layer, wherein said discards (6) are defined by a separation step such as a punching step, and the thus pre-processed mineral fiber product (1) is transported while resting on a conveyor organ (2),
   characterized in that on a traverse (13) preferably arranged above said conveyor organ (2), at least one pressurized air nozzle (8) is arranged, the position of which is adjustable and settable on said traverse (13) to the position of an aimed-at discard (6) measured transversely to the conveying direction, and that a blast pulse of said pressurized air nozzle (8) is generated precisely when said aimed-at discard (6) passes through under said pressurized air nozzle (8),
   wherein the temporal pulse width, or pulse duration, of said pressurized air blasts is limited to 0.1 s at the most.
2. The method according to Claim 1, characterized in that said pressurized air nozzle (8) is connected with a pressurized air antechamber reservoir, and activation of said pressurized air nozzle (8) is effected with an advance period which corresponds to the calculated delay of the pulse exiting from the nozzle opening (9) relative to pulse triggering at the pressurized air antechamber reservoir.
3. The method according to Claim 2, characterized in that temporal control of the blast pulses takes place under computer control as a function of the position of said discard (6) in the transport direction of said mineral fiber product (1), and of the moving velocity of said conveyor organ (2).
4. The method in accordance with any one of Claims 1 to 3, characterized in that the temporal pulse width, or pulse duration, of said pressurized air blasts is limited to less than 0.05 s.
5. The method particularly in accordance with any one of Claims 1 to 4, characterized in that in the conveying direction of said conveyor organ (2) downstream from discharge of said discards (6), an air-current gripper (21) is arranged for generating an air flow through said mineral fiber product (1) such that the pressure drop (Δp) of the flow generated by the flow resistance of said fiber product (1) multiplied by the acted-on surface area (A) exceeds the weight of said fiber product (1).
6. The method according to Claim 5, characterized in that said conveyor organ (2), or a conveyor belt (4) present at the stacking station, is made air-permeable, e.g., by perforation, and/or said mineral fiber product is placed at an elevation relative to the surface of said conveyor belt (4).
7. The method according to Claim 5 or 6, characterized in that the lower surface (24) of the air-current gripper (21), which faces the fiber product (1), is made to be air-permeable, e.g., perforated.
8. The method in accordance with any one of Claims 5 to 7, characterized in that the surface area of the bottom side (24) of said air-current gripper (21) at least approximately corresponds to the surface area of said fiber product (1) to be lifted.

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