Plant and method for connecting a web of fibrous material to a nonwoven or consolidating it therewith

Abstract

A plant and a method for connecting a web of fibrous material to a nonwoven or consolidating it therewith includes a first circulating belt on which the web of fibrous material is laid, a device for introducing a nonwoven into the plant, and a further successive circulating belt on which the nonwoven is to be connected to or consolidated with the web of fibrous material. The web of fibrous material from the first circulating belt is first laid on the nonwoven and subsequently the fibrous material is transferred onto the successive belt together with the nonwoven for connection or consolidation by use of water jets.

Claims

1. An installation for bonding or entanglement of a web of fibres with a nonwoven, comprising: a first circulating belt having upper and lower runs and arranged for having a web of fibre material deposited on the upper run, the lower run having a longitudinal extent in a direction of movement of the lower run and the web of fibre material having an upper side remote from the first circulating belt; a second circulating belt arranged beneath, parallel to and at least partially overlapping the longitudinal extent of the lower run of the first circulating belt, and receiving the web of fibre material with the upper side facing the second circulating belt; a third circulating belt arranged downstream of the second circulating belt and outside the longitudinal extent of the lower run of the first circulating belt; an apparatus for introducing a nonwoven into the installation arranged between the second and third circulating belts; wherein the second circulating belt and the apparatus for introducing the nonwoven are arranged so that the web of fibre material is deposited with the upper side of the web of fibre material on the nonwoven and the web of fibre material together with the nonwoven are transferred to the third circulating belt; and water jets arranged for bonding or entanglement of the fibre material and nonwoven on the third circulating belt.

2. The installation according to claim 1, further including at least one water bar arranged inside the first circulating belt to detach the web of fibre material from the lower run of the first circulating belt.

3. The installation according to claim 1, wherein a spacing between the lower run of the first circulating belt and the second circulating belt is greater than a thickness of the nonwoven with the fibre material deposited thereon.

4. The installation according to claim 1, wherein the lower run of the first circulating belt is spaced sufficiently close to second circulating belt to compress the fibre material therebetween.

5. A method for bonding or entanglement of a web of fibre material with a nonwoven, comprising: depositing a web of fibre material on an upper run of a first circulating belt of an installation for bonding and entanglement of a web of fibre material with a nonwoven, the web of material having an upper side remote from the first circulating belt and the first circulating belt having a lower run with a longitudinal extent in a direction of movement of the lower run; further depositing on a second circulating belt, which is arranged beneath, parallel to and at least partially overlapping the longitudinal extent of the lower run of the first circulating belt, the web of fibre material from the first circulating belt with the upper side of the web of the fibre material facing the second circulating belt; introducing the nonwoven into the installation between the second circulating belt and a third circulating belt arranged downstream of the second circulating belt and outside the longitudinal extent of the first circulating belt; transferring the web of fibre material together with the nonwoven to the third circulating belt; and bonding or entangling the nonwoven and the web of fibre material with one another on the third circulating belt by water jets.

6. The method according to claim 5, further including detaching the web of fibre material from the lower run of the first circulating belt by a water bar.

7. The method of claim 5, including compressing the fibre material between the lower run of the first circulating belt and the second circulating belt.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained by means of the accompanying drawings, in which:

(2) FIG. 1: is a first embodiment of the installation according to the invention and of the method;

(3) FIG. 2: is a second embodiment of the installation according to the invention and of the method;

(4) FIG. 3: is a third embodiment of the installation according to the invention and of the method;

(5) FIG. 3a: is a further variant of the third embodiment;

(6) FIG. 3b: is a further variant of the third embodiment;

(7) FIG. 4: is a fourth embodiment of the installation according to the invention and of the method;

(8) FIG. 5: is a fifth embodiment of the installation according to the invention and of the method; and

(9) FIG. 6: is a sixth embodiment of the installation according to the invention and of the method.

DETAILED DESCRIPTION OF THE INVENTION

(10) An inclined wire former 1 is arranged beneath a circulating filter belt 10 having an upper run 10a and a lower run 10b having a longitudinal extent in the direction of movement of the lower run. The filter belt 10, which can be in the form of an endless belt, passes around various rolls 12 and has a sloping portion 11 which ascends at the angle α in the running direction of the filter belt. The inclined wire former 1, on the covering 2 of which the filter belt 10 is supported, is arranged in the region of the sloping portion 11, beneath the filter belt 10. Beneath the covering 2 there is arranged at least one suction zone 3 which is placed under low pressure by means of pumps (not shown). The inclined wire former 1 can have a plurality of suction zones 3 which are subjected to different pressures or low pressures. The low pressure sources can preferably be in the form of controllable/adjustable vacuum pumps.

(11) In this exemplary embodiment, three fibre suspensions 8.1, 8.2 and 8.3 arranged one above the other are applied to the upper run 10a of filter belt 10 via a headbox 8. Each fibre suspension 8.1, 8.2 and 8.3 contains, in addition to water, a specific amount of solid material, which in turn consists of fibres and other added materials. Between the fibre suspensions 8.1, 8.2 and 8.3 there are arranged baffles (not shown), with which the layer thickness of the fibre suspensions can be varied individually or in total. Since the baffles separate the fibre suspensions 8.1, 8.2 and 8.3 from one another, the fibre suspensions are dewatered on the inclined wire former 1 one after the other. Mixing of the fibre suspensions 8.1, 8.2 and 8.3 is thereby prevented and the ply purity of the individual layers of fibre material is improved. Via the at least one suction zone in conjunction with the controllable/adjustable vacuum pumps, each layer of a fibre suspension 8.1, 8.2 and 8.3 can be exposed to a separate low pressure, whereby different mixtures of water with fibres in each fibre suspension can be processed.

(12) In this exemplary embodiment, the fibre suspensions 8.1 and 8.3, which on further processing form the outer layers or the cover layer for the middle layer of fibre suspension 8.2, can consist at least in part of short synthetic fibres such as, for example, polyester, polyamide or polyolefin. Fibre mixtures of synthetic and natural fibres are also possible. The outer layers can likewise also consist of 100% pulp. The middle fibre suspension can consist of natural fibres, which have a high water retention capacity.

(13) The thickness of the plies is adjustable by the baffles by varying the delivery of the fibre suspensions 8.1, 8.2 and 8.3 via the headbox 8. In the case of a sandwich nonwoven, for example, plies of equal thickness can be produced, or the plies can be produced with a graduation of, for example, 10%, 80% and 10% thickness. The weight per unit area of each ply of fibre material 9 can indirectly also be adjusted thereby.

(14) It is of course also possible to deliver only one fibre suspension, so that a single ply of fibres forms after the removal of water.

(15) The filter belt 10, which is permeable to liquids and gases, transports the fibre suspensions 8.1, 8.2 and 8.3 arranged one above the other over the sloping portion 11 over the inclined wire former 1. Owing to gravity and the low pressure acting on the fibre suspensions 8.1, 8.2 and 8.3, the fibre suspensions are dewatered, whereby in this example a web of fibre material 9 having three plies of fibres is formed.

(16) The web of fibre material 9 is transported on the belt 10 in the direction indicated by the arrow, first over a horizontal portion and then further over a descending sloping portion. After the descending sloping portion, the web of fibre material 9 is transferred upside down, around a roll 12, onto a further circulating belt 14, which is likewise guided around a plurality of rolls 13. The circulating belt 14 is arranged beneath, approximately parallel to and at least partially overlapping the longitudinal extent of the lower run 10b or circulating belt 10, the spacing between the belts 10, 14 being greater than the thickness of the web of fibre material 9. Alternatively, the belts 10, 14 can also be arranged with such a spacing that the web of fibre material 9 is compressed. In the region in which the belts 10 and 14 run parallel there is arranged inside the circulating belt 10 at least one water bar 17 with which the web of fibre material 9 is pre-entangled and detached from the belt 10. The associated suction means 18 is situated inside the circulating belt 14. Downstream in the material running direction of the fibre material 9 and beneath the inclined wire former 1 with the circulating belt 10 there is arranged a further circulating belt 16 on which the web of fibre material 9 is processed further. The circulating belt 16 is so arranged that it is outside of, i.e. does not overlap with, the longitudinal extent of the lower run of belt 10. Between the belts 14 and 16 there is arranged an intake roll 21 by which a nonwoven 20 is introduced onto the circulating belt 16 beneath the web of fibre material 9. Since the web of fibre material 9 is transported further by the circulating belt 10 downstream of the descending sloping portion upside down, the upper side of the web of fibre material 9 is deposited on the nonwoven 20. In this exemplary embodiment, the nonwoven 20 is unwound from a store or a roll of material. Alternatively, it is also possible to arrange in place of the roll of nonwoven a roller card by means of which the nonwoven 20 is introduced directly into the entanglement installation shown in FIG. 1. The spacings between the rolls 13, 21 and 15 are on the one hand kept small in order to minimise the nip for the further transport of the fibre material 9; on the other hand, the intake roll 21 can be adjustable, in order to introduce the nonwoven 20 quickly. Final bonding between the nonwoven 20 and the fibre material 9 takes place in the region of the belt 16 by bonding of the fibre material 9 with the nonwoven 20 by means of at least one water bar 17 and compression. The water jet of the water bar 17 thereby strikes the fibre material 9, which is bonded with the nonwoven 20.

(17) FIG. 2 shows a circulating belt 10 in which there is arranged above a sloping portion 11 a fibre applicator 4 with which pulp, for example, is delivered as loose fibres. Unlike the exemplary embodiment of FIG. 1, it is here possible to process not only wet-laid fibres but also dry fibres. The web of fibre material 9 is transported further in the material flow direction over a horizontal portion to a descending sloping portion and is transferred upside down onto a nonwoven 20 by a roll 12. In order that the dry fibres do not slip off the belt 10 it is possible, for example, to arrange a fibre wetting means (not shown) on the horizontal portion of the belt 10, so that the loose assembly of dry fibres acquires a certain degree of cohesiveness.

(18) In this exemplary embodiment, the nonwoven 20 can likewise be unwound from a roll or supplied directly from a roller card. The supply of the nonwoven 20 takes place in the region of the roll 12 in such a manner that a first compacting between the nonwoven 20 and the web of fibre material 9 takes place. This bonding is enhanced on a downstream belt 14 by at least one water bar 17. The downstream belt 14 is arranged beneath the belt 10 and runs parallel thereto at least in part. The spacing between the belts 10, 14 is greater than the thickness of the nonwoven 20 with the web of fibre material 9. Alternatively, the nonwoven 20 can also be delivered onto the belt 14 by an intake roll 21, the web of fibre material 9 being deposited upside down on the nonwoven 20 in the region of the intake roll 21.

(19) The exemplary embodiment of FIG. 3 likewise shows two circulating belts 10, 14 which are arranged in parallel at least in part, the circulating belt 14 being arranged beneath the belt 10. Here too, a web of fibres is delivered onto the belt 10 via a fibre applicator 4 or via an inclined wire former 1. In the region of a descending sloping portion of the belt 10 there is arranged an intake roll 21 by which a nonwoven 20 is applied to the web of fibre material 9. By means of a downstream roll 12, with which the web of fibre material 9 and the nonwoven 20 are deflected onto an approximately horizontal belt 14, compacting between the nonwoven 20 and the fibre material 9 takes place, even though the spacing between the belts 10, 14 is greater than the thickness of the nonwoven 20 with the fibre material 9. Only when the nonwoven 20 with the fibre material 9 has left the region between the belts 10, 14 and is lying only on the belt 14 does final entanglement between the nonwoven 20 and the fibre material 9 take place by means of at least one water bar 17. An associated suction means 18 is arranged inside the circulating belt 14.

(20) A further variant in FIG. 3a shows in a further arrangement at least one water bar 17 inside the belt 10, whereby the web of fibre material 9 is detached from the belt 10. Compacting does not take place at this point because the spacing between the belts 10, 14 is greater than the thickness of the nonwoven 20 with the fibre material 9.

(21) The exemplary embodiment in FIG. 3b shows instead of the intake roll 21 a suction drum 22 which is acted upon by at least one water bar 17. This effects entanglement of the web of fibre material 9 with the nonwoven 20, compacting between the nonwoven 20 and the fibre material 9 then taking place as a result of the deflection around the roll 12. The downstream water bars 17 inside the belt 10 likewise ensure complete detachment of the fibre material 9 from the belt 10, since here too the spacing between the belts 10, 14 is greater than the thickness of the nonwoven 20 with the fibre material 9. The downstream further entanglement between the nonwoven 20 and the web of fibre material 9 takes place in a region on the belt 14 in which the belts 10, 14 are no longer running in parallel.

(22) The exemplary embodiment of FIG. 4 likewise shows in the region of a descending portion an intake roll 21 around which a nonwoven 20 is brought into contact with the web of fibre material 9. By subsequent deflection by a roll 12, compacting between the nonwoven 20 and the web of fibre material 9 takes place. Instead of being deposited directly on a belt 14 arranged beneath the belt 10, the nonwoven 20 with the web of fibre material 9 is guided at least in part around a suction drum 22, on which the nonwoven 20 is entangled with the fibre material 9 by means of water bars 17. Further transport to a circulating belt 14 having at least one further downstream water bar 17 is effected by a downstream roll 19.

(23) In the exemplary embodiment of FIG. 5, the fibres 9 deposited on the belt 10 are entangled by means of water bars 17 in the first horizontal portion. In the region of the descending portion, the entangled fibre material 9 is detached from the belt 10 by a water bar 17 and transferred with its upper side to the suction drum 22 and guided around the drum. In this exemplary embodiment, the suction drum 22 rotates clockwise. Beneath the suction drum 22 a nonwoven 20 is supplied by an intake roll 21, so that bonding between the nonwoven 20 and the lower side of the fibre material 9 takes place over a portion of the periphery of the suction drum 22, at least one water bar 17 bonding the fibre material and the nonwoven with one another. Downstream rolls 19 effect further transport to a further circulating belt 14 on which the nonwoven 20 is again bonded with the fibre material 9 by means of water bars 17.

(24) In the exemplary embodiment of FIG. 6 too, a suction drum 22 is arranged in the region of the descending portion. A nonwoven 20 is guided around the suction drum 22. The fibre material 9 is detached from the belt 10 in the region of the point of contact between the fibre material 9 and the suction drum 22. The fibre material 9 is thereby situated beneath the nonwoven 20 and is entangled with the nonwoven 20 with its upper side by means of water bars 17 on the following periphery of the suction drum 22. Rolls 19 arranged downstream effect transfer to a further circulating belt 14, which can be arranged beneath the belt 10, it being possible for further entanglement between the nonwoven 20 and the fibre material 9 to take place subsequently by means of water bars 17.

(25) It is common to all the exemplary embodiments that the fibres are deposited on the first belt 10 in the form of loose pulp or wet-laid by means of an inclined wire former 1. The nonwoven 20 can be supplied to the installation as a card web from a supply roll or it can be supplied to the installation directly as a roller card web from a roller card. The nonwoven 20 can be produced from short or endless fibres. Furthermore, the bonding of the fibre material 9 with the nonwoven 20 does not take place in a region in which two belts are guided in parallel. Thus, unlike in the prior art, the loose fibres do not have to be bonded with the nonwoven upside down between two belts. Alignment of the belts with one another and synchronisation of the belts speeds are thus not necessary. Although it is possible after the first bonding between the nonwoven 20 and the fibre material 9 to compact the two plies by means of belts arranged in parallel, this is not necessary for the method and the installation. The water bars generate twisting and thus entanglement of the fibres with one another by means of the high-pressure water jets or, at a lower pressure, serve to detach the fibres or the nonwoven from a belt or a drum.