EP1249523A1 - Randomising roller and its use - Google Patents

Abstract

One or more cylinders are mounted for horizontal lateral motion, relative to the supports and parallel to the axis of cylinder rotation. Note -The carding cylinders referred to here, have inclined teeth. An Independent claim is included for the corresponding method of treating a non-woven cloth. Preferred features: The cylinder is associated with equipment causing lateral reciprocation along its axis. There is also at least one combing and/or carding cylinder without lateral motion, another with lateral motion and/or a fixed cylinder. The cylinder with lateral displacement, follows one without. At least two carding cylinders with lateral displacement follow the comb in series and are separated by one or more fixed cylinders. Carding cylinder length is increased beyond that of the preceding cylinder, by the maximum amplitude of reciprocation. Reciprocating cylinders are constructed in low density material, preferably a light metal or alloy. The reciprocating carding cylinder has

Description

The subject of the present invention is a jamming cylinder, an assembly comprising two interfering cylinders, and their uses.

Interference cylinders are known. Such cylinders are known and used for carding nonwoven sails.

Carded sails are known, these sails presenting an anisotropy problem. Such sails are perfectly suited for the manufacture of yarns where there is a demand a parallelism of the fibers, but are not suitable as such for the manufacture of non-woven products, since for the latter a maximum isotropy is requested. Indeed, the resistance of a veil is much greater in the fiber alignment direction, only in a direction perpendicular to fiber alignment. For the manufacture of nonwoven products, we want obtain a veil having substantially the same resistance in directions perpendicular.

The card has the essential role, in nonwoven, to produce a light, coherent veil, homogeneous and as regular as possible. The regularity on the surface of the veil is obtained by a work of separation of the tufts and individualization of the fibers, this work being carried out by teeth present on the carding cylinders.

This work is carried out with a stretching of the material and an alignment of the fibers in the direction of the fibers through the machine.

This preferred orientation results in a parallelization of the fibers and therefore a lack of isotropy of the veil produced at the card painter.

We have already tried to reduce this orientation of fleece for nonwoven by means of a jumble cylinder or jamming cylinder.

A pell-mell or criss-cross cylinder is a cylinder rotating in the same direction than the drum, and having teeth inclined in the same direction as those of the drum (forward with respect to the direction of rotation). This cylinder creates at the point of tangency with the drum a non-crossing carding point which tends to misalign the fibers.

An interfering cylinder is a cylinder rotating in the opposite direction to that of the painter and having his teeth tilted in the same direction as those of the painter (backwards with respect to the direction of rotation). This cylinder creates at the point of tangency with the painter a crossing point of skin which is accompanied of a condensation of the matter. This condensation causes disorientation fibers, which tend to go slightly crooked, thereby decreasing the anisotropy of the product. A fiber which arrives more or less aligned is placed slightly crooked, one way or the other, at random or according to its low initial tilt.

The object of the present invention is to improve the isotropic nature of the webs. cards by creating a positive disorientation of the fibers in the veil.

We have now noticed that by causing a lateral movement of the cylinder jammer with respect to the direction of advancement of the veil it was possible to increase the inclination of the fibers in the final veil and therefore to increase the isotropic character of nonwoven sails.

The present invention relates to a unit for working fiber webs, said unit comprising a support and at least one interfering cylinder rotatably mounted about its axis relative to the support, characterized in that at least one cylinder or part of cylinder is mounted movable relative to the support so as to undergo at least one lateral relative movement, advantageously horizontal, relative to the support at least in a direction parallel to the axis of rotation of the cylinder.
By means of such a unit, a fiber which enters or passes over the cylinder with relative lateral movement in a manner substantially aligned with respect to the direction of production (hereinafter machine direction or direction of advance of the web) or direction parallel to the plane perpendicular to the axis of rotation of the cylinder, is deflected at least partially in a direction perpendicular to the machine direction (hereinafter called cross direction). This lateral movement of the jamming cylinder having teeth acting on the fibers of the web then causes the fibers to pivot or deflect, in addition to the deflection obtained by the braking effect due to condensation.

According to an advantageous embodiment, the cylinder or part of cylinder mounted movable relative to the support so as to undergo at least one relative movement lateral is associated with a device to generate a lateral back and forth movement of the cylinder or part thereof in a direction parallel to the axis of rotation of the cylinder. For example, the device generating a lateral movement back and forth is a device comprising one or more means for adjusting the frequency and / or the amplitude of the back-and-forth movement, in particular as a function of the speed of scrolling of the veil and / or the length of the fibers of the veil and / or the isotropy desired veil.

According to a characteristic of an embodiment, the unit further comprises at minus a comber and / or a jamming cylinder without lateral movement and / or a jamming cylinder with lateral movement and / or a fixed cylinder. Such a unit is therefore for example a card generally comprising two or more than two interfering cylinders placed in series one behind another.

For example, the interfering cylinder with lateral displacement is located after a jamming cylinder without lateral displacement. The additional deviation provided by such a unit is then simple, since due to a single interfering cylinder with lateral displacement.

When the unit has two or more interfering cylinders with lateral displacement (said cylinders being advantageously placed one after the other on the other after the painter and possibly being separated from each other by one or several fixed cylinders), it is possible to obtain an additional deflection double. The double deflection is done for example in two stages, namely a first time passing from the fiber from the doffer to the first jammer with relative lateral displacement, and a second time in the passage of the fiber from a interferer (with or without relative lateral displacement) to another (with displacement relative lateral).

According to a feature of an embodiment, the interfering cylinder has a length at least equal to the length of the cylinder which precedes it increased by the maximum range of back and forth movement of the interfering cylinder at lateral displacement.

The unit advantageously comprises one or more mechanical, electromechanical and / or electronic means regulating or controlling, continuously or not or substantially continuously, the amplitude and / or the frequency of the movement of the interfering cylinder with lateral movement.
When the unit comprises two interfering cylinders with lateral displacement, the unit also comprises mechanical, electromechanical or electronic means for adjusting and / or controlling, continuously or not, the phase shift of the lateral movement of a interfering cylinder with respect to to the lateral movement of the other interfering cylinder, for frequencies of movement equal or not and / or for amplitudes of movement equal or not. For this embodiment, each interfering cylinder with lateral displacement is advantageously associated with a means independently regulating or controlling, continuously or not, the frequency and / or the amplitude of the lateral displacement.

According to an advantageous detail, the interfering cylinder with lateral displacement is constructed of a low density material, preferably light metal or light metal alloy. For example, the cylinder is made of material low weight composite. This low weight of the mobile jamming cylinder allows reduce the masses subjected to lateral relative movement (reciprocating).

According to a particular detail of an embodiment, the interfering cylinder with lateral displacement has two lateral flanges pierced in their center and a shaft extending through the cylinder through said flanges, said shaft having means acting on the flanges to ensure lateral movement of the cylinder. This shape allows the traction or pushing force to be distributed over the two side flanges.

It will be noted that the disorientation obtained by the system or unit according to the invention can be added to or subtracted from that obtained by condensation.
Since the disorientation obtained by condensation is random, while that obtained by the interfering cylinder with lateral displacement is positive, it is not possible that the algebraic sum of the two orientations is zero for each fiber and at all times. The average deviation of the fibers will be at least on average greater than that obtained only by condensation (zero deviation or substantially zero). In other words, the orientation of the fibers of the veil will be modified so that the veil will have a greater proportion of fibers inclined relative to the direction of advance of the veil or an average inclination (average calculated on the angle in absolute value of the inclination of the fibers).

• vitesse de déplacement latéral du cylindre brouilleur ;
• course du déplacement latéral ;
• etc.

En agissant sur l'un ou l'autre de ces paramètres, en particulier sur les deux paramètres précités, il est possible d'obtenir au moins sensiblement le résultat recherché (par exemple l'isotropie recherchée ou plus exactement un caractère anisotrope particulier), ou à tout le moins de se rapprocher du résultat désiré.The intensity of the disorientation due to condensation can be influenced by certain parameters, such as the relative speed of the two tangent cylinders (for example between the combing cylinder and the interfering cylinder), this influence being however random. By using an interfering cylinder with lateral displacement, it is possible to influence the disorientation in a positive way, by acting for example on one or more parameters (possibly simultaneously or successively), such as:

• lateral movement speed of the interfering cylinder;
• lateral displacement stroke;
• etc.

By acting on one or the other of these parameters, in particular on the two aforementioned parameters, it is possible to obtain at least substantially the desired result (for example the desired isotropy or more exactly a particular anisotropic character), or at the very least get closer to the desired result.

The invention also relates to an installation for preparing a web of nonwoven, said installation having the improvement of presenting at least a unit according to the invention.

The subject of the invention is also a process for preparing a nonwoven web, comprising at least one step of preparing a veil and a scrambling step veil by means of at least one jamming cylinder, characterized in that one operates the scrambling step at least by means of a unit according to the invention so to subject the veil or part of it to a transverse movement by report to the direction of advancement of the veil.

- la figure 1 représente schématiquement en élévation une unité de trois cylindres ;

- la figure 2 est une vue de haut de l'unité de la figure 1 ; et

- les figures 3 à 6 sont des vues montrant l'effet du cylindre à mouvement latéral sur une fibre.

Special features and details of the invention will emerge from the following description, in which reference is made to the accompanying drawings.
In these drawings,

- Figure 1 shows schematically in elevation a unit of three cylinders;

- Figure 2 is a top view of the unit of Figure 1; and

- Figures 3 to 6 are views showing the effect of the cylinder with lateral movement on a fiber.

The unit shown schematically in Figures 1 and 2 has three cylinders, know a combing cylinder 1, a first jamming cylinder 2 which receives the fibers coming from the comb cylinder 1, and a second jamming cylinder 3 which receives the fibers coming from the jamming cylinder 2.

The cylinders 1,2,3 are rotated, the cylinders 1 and 3 in the direction clockwise, while cylinder 2 counterclockwise. The general meaning advancement of the fibers or the veil is represented by arrow 4. This general sense is included in a plane perpendicular to the axes 1A, 2A, 3A of rotation of the 1,2,3 cylinders.

The cylinder 2 is associated with a mechanism 2B intended to generate a movement of back and forth (arrow 5) of cylinder 2 in a direction parallel to the axis of rotation of cylinder 2. This back-and-forth movement is therefore transverse to the general direction of sail advance (arrow 4).

The cylinder 2 is able to undergo a maximum lateral displacement Lmax. Therefore for prevent fibers from the combing cylinder 1 from passing over the cylinder 2, the cylinder 2 has a length L2 at least equal to the length L1 of the comb cylinder 1 increased by the maximum lateral displacement Lmax. For example, the length L2 is between 1 and 1.3 times the sum L1 + Lmax.

The length L3 of the interfering cylinder is at least equal to the length L1 + 2 times Lmax, or at least equal to L2 + Lmax, for example included between 1 and 1.3 times the sum L2 + Lmax.

It is clear that if only part of the length of cylinder 1 is used, the cylinders 1, 2 and 3 can have the same length.

The arrow 5 shows the direction of the transverse direction of movement of the cylinder mobile jammer, which also corresponds to the direction in which one wishes partially tilt the fibers or fibers.

The arrow 4 shows the direction of advance of the fibers, preferred direction in which the fibers tend to orient.

Figures 3 to 6 show the effect of lateral movement of the jamming cylinder 2 on a fiber 8.

In FIG. 3, a fiber 8 arrives from the comber 1, substantially aligned in the direction of advance 4, this fiber having its first end 8A entering contact with teeth of the jamming cylinder 2 which undergoes lateral displacement 6, while being driven in rotation. The fiber 8 thus undergoes a disorientation α1 by report to the general management of advancement 4.

In Figure 4, there is shown the displacement of the end 8A of the fiber in the direction of arrow 6, while being moved in the direction of arrow 4 by rotation of cylinder 2. In this figure, the tail 8B of the fiber 8 is substantially ready to leave the paint cylinder 1. In the form shown, cylinder 2 is here at the end race.

In FIG. 5, the fiber 8 is ready to pass over the cylinder 3, while another fiber 9 is ready to pass from the combing cylinder 1 to the cylinder 2. The jamming cylinder 2 is here moved in the direction of arrow 7.

In FIG. 6, the fiber 8 has its head 8A engaged on the interfering cylinder 3. From makes the movement of the jamming cylinder 2 in the direction 6B, the tail 8B of the fiber 8 then undergoes a displacement to create an additional disorientation α2. Fiber 9, for its part, undergoes a disorientation β1 relative to the direction advancement 4. The fiber 9 therefore undergoes disorientation or inclination by compared to direction 4, which is opposite to the disorientation or inclination of the fiber 8.

Cylinder 2 then reaches the end of its travel and then moves back into the direction 6.

The phenomenon described above occurs on all of the fibers constituting the card web, the fibers are alternately disoriented in one direction and then in an opposite direction, with a frequency which depends on the speed of movement side of the jamming cylinder, and an amplitude which depends on the amplitude of the transverse movement of this cylinder. This results in a veil having a better jamming than in a traditional veil prepared without jamming cylinder with lateral displacement.

Cylinder displacement parameters can be changed at will jammer 2. For example, depending on the length or average length of the fibers, it is possible to modify or adapt the amplitude of movement and / or the frequency of movement. It is also possible to modify the speed of movement of the cylinder 2 in one direction relative to that in the opposite direction. For example, the displacement of cylinder 2 in direction 6A is rapid, while displacement of cylinder 2 in direction 6B is slow.

• les cylindres brouilleurs 2,3 et leurs axes sont plus longs pour permettre l'amplitude de la course sans perte de contrôle du voile ;
• les axes du ou des cylindres brouilleurs à déplacement latéral ou axial doivent être supportés par des paliers autorisant le déplacement axial aux fréquences désirées ;
• le ou les cylindres brouilleurs à déplacement axial ou latéral sont avantageusement construits en matériau léger pour réduire la masse à laquelle il faut communiquer un mouvement de va-et-vient ; ces cylindres présenteront toutefois de préférence une flèche très faible, notamment pour éviter ou réduire des problèmes de vibrations et améliorer la régularité du voile ;
• le cylindre brouilleur 2 présente avantageusement des flasques fixées à l'axe ou l'arbre de rotation de manière suffisante pour reprendre et résister aux efforts importants en fin de course du mouvement, c'est-à-dire aux moments de l'inversion du mouvement, les axes ou arbres étant de préférence traversant.

Special features of the unit shown schematically in Figures 1 and 2 are:

• the jamming cylinders 2,3 and their axes are longer to allow the amplitude of the race without loss of sail control;
• the axes of the interfering cylinder or cylinders with lateral or axial movement must be supported by bearings allowing axial movement at the desired frequencies;
• the interfering cylinder or cylinders with axial or lateral movement are advantageously constructed of light material to reduce the mass to which it is necessary to communicate a back-and-forth movement; these cylinders will however preferably have a very small deflection, in particular to avoid or reduce problems of vibration and improve the regularity of the web;
• the jamming cylinder 2 advantageously has flanges fixed to the axis or the rotation shaft sufficiently to take up and withstand the large forces at the end of the movement, that is to say at the moments of the reversal of the movement. movement, the axes or trees preferably being through.

• possibilité de ne plus devoir utiliser, dans certains cas, de cylindre pêle-mêle en association à des cylindres brouilleurs ;
• possibilité d'obtenir une isotropie suffisante avec un cylindre peigneur et un cylindre brouilleur à déplacement latéral ;
• possibilité de réduire la condensation sur les cylindres brouilleurs, d'où possibilité de produire des voiles plus fins ;
• possibilité d'accroítre les vitesses de sortie grâce par exemple à une réduction de la condensation ;
• dans le cas de cardes suivies d'un étaleur nappeur, l'étireur de nappe qui suit ce dernier (dont le but est de croiser les fibres) pourrait ne plus être nécessaire.
• Etc.

Advantages of the unit according to the invention, other than that of making it possible to prepare more isotropic sails, are:

• possibility of no longer having to use, in certain cases, pell-mell cylinder in association with interfering cylinders;
• possibility of obtaining sufficient isotropy with a combing cylinder and a jamming cylinder with lateral displacement;
• possibility of reducing condensation on interfering cylinders, hence possibility of producing thinner sails;
• possibility of increasing output speeds, for example by reducing condensation;
• in the case of cards followed by a lapper spreader, the tablecloth stretcher which follows the latter (the purpose of which is to cross the fibers) may no longer be necessary.
• Etc.

Claims (14)

Unit for working webs of fibers, said unit comprising a support and at least one interfering cylinder mounted to rotate about its axis relative to the support, characterized in that at least one cylinder or part of cylinder is mounted movable relative to the support so as to undergo at least one lateral relative movement, advantageously horizontal, relative to the support at least in a direction parallel to the axis of rotation of the cylinder. Unit according to claim 1, characterized in that the cylinder or part of cylinder mounted movable relative to the support so as to undergo at least one relative lateral movement is associated with a device for generating a lateral reciprocating movement of the cylinder or part thereof in a direction parallel to the axis of rotation of the cylinder. Unit according to claim 2, characterized in that the device generating a lateral reciprocating movement is a device comprising one or more means for adjusting the frequency and / or the amplitude of the reciprocating movement , in particular depending on the speed of travel of the web and / or the length of the fibers of the web and / or the desired isotropy of the web. Unit according to one of Claims 1 to 3, characterized in that it further comprises at least one comber and / or a jamming cylinder without lateral movement and / or a jamming cylinder with lateral movement and / or a fixed cylinder. Unit according to claim 4, characterized in that the interfering cylinder with lateral displacement is located after a interfering cylinder without lateral displacement. Unit according to Claim 4, characterized in that it comprises at least two interfering cylinders with lateral displacement, the said cylinders being advantageously placed one after the other after the doffer and possibly being separated from one other by one or more fixed cylinders. Unit according to any one of Claims 1 to 6, characterized in that the interfering cylinder has a length at least equal to the length of the preceding cylinder increased by the maximum amplitude of reciprocating movement of the interfering cylinder with lateral displacement. Unit according to any one of the preceding claims, characterized in that it comprises one or more mechanical, electromechanical and / or electronic means regulating or controlling, continuously or not or substantially continuously, the amplitude and / or the frequency of movement of the interfering cylinder with lateral movement. Unit according to any one of the preceding claims, characterized in that it comprises two interfering cylinders with lateral displacement, and mechanical, electromechanical or electronic means for adjusting and / or controlling, continuously or not, the phase shift of the lateral movement of an interfering cylinder with respect to the lateral movement of the other interfering cylinder, for frequencies of movement equal or not and / or for amplitudes of movement equal or not. Unit according to the preceding claim, characterized in that each interfering cylinder with lateral displacement is associated with means regulating or controlling independently, continuously or not, the frequency and / or the amplitude of the lateral displacement. Unit according to any one of the preceding claims, characterized in that the interfering cylinder with lateral displacement is constructed from a low density material, advantageously from light metal or a light metal alloy. Unit according to any one of the preceding claims, characterized in that the interfering cylinder with lateral displacement has two lateral flanges pierced in their center and a shaft extending through the cylinder by crossing said flanges, said shaft having means acting on the flanges to ensure lateral movement of the cylinder. Installation for preparing a nonwoven web, said installation having the improvement of presenting a unit according to any one of claims 1 to 12. Method for preparing a nonwoven web, comprising at least one step for preparing a web and a step for scrambling the web using at least one scrambling cylinder, characterized in that the step is carried out jamming at least by means of a unit according to one of claims 1 to 12 so as to subject the web or a part thereof to a transverse movement relative to the direction of advance of the web.

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