EP2000429A1 - Method for winding a plastic film in order to make a reel, the device for implementing the method and the reel obtained - Google Patents

Abstract

The method involves winding a plastic film (F) on a rigid tubular support (1) i.e. rolling tube, temporarily acting as a winding spool, where the support is made of non deformable rigid material e.g. steel. The support is subjected to action of a pneumatic cylinder having a piston head cooperated with an end of the support in a sealed manner, to eject the support in combination with the transmission of compressed air for creating air cushion at external periphery of the support to form a jumbo reel (B) without the spool. The support is reintroduced in a winding machine to proceed next rolling. An independent claim is also included for a device for winding a plastic film to make a reel.

Description

The invention relates to the technical sector of the treatment of materials, including plastics.

More particularly, the invention relates to the production of coils of a plastic film.

It is well known to use, for the production of one or more coils, machines generally designated by the generic term of winders. The plastic film considered is unrolled from a mother reel and then wound with return cylinders and motorized cylinders, along the entire width of the mother reel or according to different widths of different widths resulting from different cuts, on one or more cardboard tubes. These machines are applicable for producing coils of different types of plastic films. This is particularly the case of stretchable plastic films.

From this basic design, after the winding operation and regardless of the techniques used, the coil obtained has a cardboard tube which acts as a mandrel on which is wound, in variable diameters and lengths, the film plastic. In other words, in all cases, the coil has a mandrel most often formed by a cardboard tube, as indicated. This cardboard tube is necessary, not only for the winding of the plastic film, but also for the holding of the coil at the time of its use and / or its subsequent handling by means of, for example, an unwinding apparatus.

Indeed, in the absence of the cardboard tube, the winding forces resulting from different winding turns to achieve a perfectly cylindrical coil, especially at its central area winding, tend to cause crushing of the entire coil. This phenomenon is all the more important for the winding of a stretchable plastic film where the winding forces are important.

It is conceivable that the use of this cardboard tube has many disadvantages. In particular, this carton significantly increases the cost of the coil. It is also necessary to have at the place of manufacture of the reels, a large stock of tubes requiring a large storage location, and therefore significant investments. Finally, it is appropriate to manage the waste resulting from the use of the reels, since after having completely unwound the reel, the cardboard tube is not reusable.

As an indication, for a pallet comprising 360 coils, the 360 cardboard tubes represent waste with a weight and volume of 144 Kg and a cost of 63 €.

The object of the invention is to remedy these disadvantages in a simple, safe, effective and rational manner.

The problem to be solved by the invention is to no longer use a cardboard tube to perform the winding operation as such, with the possibility of shipping reels of plastic film no longer having this tube. cardboard, and more generally no support mandrel.

Solutions have been proposed to try to make the coils not having a cardboard tube to be shipped without any mandrel. However, the solutions chosen are not satisfactory since the retained coils are deformed under the effect of the winding tension of the plastic film, especially in the case of a plastic film of stretchable material. In other words, these attempts have not made it possible to propose, on an industrial level, coreless coils suitable for use under normal conditions.

• on enroule le film sur un support tubulaire rigide pour réaliser la bobine ;
• on soumet le support à l'action de moyens aptes à assurer son éjection de manière à former une bobine sans mandrin.

To solve such a problem, it has been conceived and developed a method for winding a plastic film in order to produce a coil, according to which:

• the film is wound on a rigid tubular support to form the coil;
• the support is subjected to the action of means capable of ensuring its ejection so as to form a coil without mandrel.

Another problem to be solved by the invention is to be able to use a machine of coiling type, in accordance with that commonly used by a person skilled in the field of winding, without making significant changes, but simple adjustments.

• on enroule le film sur un tube faisant office temporairement de mandrin d'enroulement ;
• on soumet le tube, après enroulement, à l'action d'un vérin dont la tête du piston coopère, d'une manière étanche, avec une extrémité dudit tube en vue de son éjection en combinaison avec un envoi d'air comprimé pour créer un coussin d'air à la périphérie externe du tube ;
• on réintroduit le tube dans une machine de bobinage pour un prochain enroulement.

To solve such a problem:

• the film is wound on a tube temporarily acting as a winding mandrel;
• the tube is subjected, after winding, to the action of a jack whose piston head cooperates, in a sealed manner, with an end of said tube with a view to its ejection in combination with a compressed air supply to create an air cushion at the outer periphery of the tube;
• we reintroduce the tube in a winding machine for a next winding.

For the implementation of the method according to the invention, the device comprises a winding tube of rigid material shaped to cooperate, after winding of the film, with a pneumatic jack adapted to exert a thrust force and to send air under pressure, so as to create a cushion or an air film at the periphery of said tube for its ejection so as to form a coil without mandrel.

According to another characteristic, the winding tube delimits an internal recess in communication, on the one hand, with the outside by a plurality of microperforations formed at the periphery of said tube and, on the other hand, with an internal centering span. shaped to receive, in a sealed manner, the piston head connected to a compressed air compressor.

In order to solve the problem of ensuring the ejection of the tube by considering the tension forces exerted on the latter resulting from the winding, particularly in the case of a stretchable film, the internal centering surface is formed at one of the ends of the tube and is in communication with the internal chambering of said tube and with an internal channel of the head and the piston rod for the injection of air.

The piston head peripherally has arrangements capable of sealing after introduction of the centering bearing.

The arrangements consist of at least one O-ring.

In a preferred embodiment, the tube is made of a non-deformable rigid material, in particular steel.

Given the basic characteristics of the invention, it appears that to achieve the coil as such, simply replace the tube cardboard generally used, by the steel tube or other non-deformable material, which tube is reused for the realization of another coil.

The plastic film reel obtained, has a completely free and smooth bore adapted to receive, at the time of use, at least one handling tip.

• la figure 1 est une vue à caractère purement schématique d'une bobineuse utilisant un tube carton pour la réalisation de bobines ;
• la figure 2 est une vue à caractère purement schématique montrant la même machine que celle illustrée figure 1 où le tube en carton est remplacé par un support tubulaire rigide faisant office d'axe d'enroulement ;
• la figure 3 est une vue en perspective d'une partie du dispositif d'éjection du tube support d'enroulement, avant actionnement du vérin d'éjection ;
• la figure 4 est une vue en perspective du tube d'enroulement ;
• la figure 5 est une vue en perspective d'une bobine résultant de la mise en oeuvre de l'invention ;
• les figures 6, 7 et 8 sont des vues en coupe à caractère schématique montrant l'éjection du tube support d'enroulement pour la réalisation d'une bobine sans mandrin.

The invention is described below in more detail with reference to the figures of the accompanying drawings, in which:

• the figure 1 is a purely schematic view of a winder using a cardboard tube for producing coils;
• the figure 2 is a purely schematic view showing the same machine as illustrated figure 1 where the cardboard tube is replaced by a rigid tubular support acting as a winding axis;
• the figure 3 is a perspective view of a part of the ejection device of the winding support tube, before actuation of the ejection cylinder;
• the figure 4 is a perspective view of the winding tube;
• the figure 5 is a perspective view of a reel resulting from the implementation of the invention;
• the Figures 6, 7 and 8 are schematic sectional views showing the ejection of the winding support tube for the realization of a mandrelless coil.

As indicated, the method according to the invention uses a machine of the coiling type essentially comprising, in a known manner, a mother reel (B) of the considered plastic film (F) which is unwound, via different removals and drives, for make the coil, the cardboard tube (T) ( figure 1 ) is replaced, according to the invention, by a rigid tubular support (1) in particular in the form of a steel tube or other dimensionally stable material. The coil as such remains in the known manner. On the other hand, at the exit of the winder, the spool is equipped with the winding support (1) which is subjected to the action of a means (2) capable of ensuring its ejection so as to form a mandrel-free spool ( figure 5 ).

As will be indicated in the following description, the winding support (1) is subjected to the action of a jack (2) whose piston head (2a) cooperates with an end of said support for its ejection in combination with the formation of an air film to create an air cushion at the outer periphery of said support. Advantageously, the support (1) is constituted by a steel tube.

The winding tube (1) defines an internal recess (1a) in communication with the outside by a plurality of microperforations (1b) formed at the periphery (1). The internal recess (1a) is in communication, at one end of the tube (1), with an internal centering surface (1c). The communication between the recess (1a) and the internal span (1c) is effected for example by means of a coaxial opening (1d). The internal bearing (1e) is intended to receive, in a sealed manner, the head (2a) of the piston whose rod (2b) is in communication by an internal channel (2c) with a pneumatic unit (3) for the sending compressed air.

In the illustrated embodiment, the end of the piston head (2a) peripherally has arrangements capable of sealing after insertion into the centering surface (1c). For example, these arrangements consist of at least one O-ring (4).

• Le support d'enroulement (1) est disposé dans une bobineuse du type de celle illustrée figure 2, en lieu et place du tube de carton (T) généralement utilisé. La formation de la bobine sur le tube ou support d'enroulement (1) demeure donc réalisée de manière classique. A la sortie de la bobineuse, la bobine (BO) est équipée du tube en acier (1).
• La bobine (BO) avec le tube (1) est transférée, par tout moyen connu et approprié, notamment d'une manière entièrement automatique, vers un poste d'éjection comprenant notamment au moins le vérin pneumatique (2).
• La bobine (BO) avec le tube (1) est positionnée et centrée dans un berceau d'appui, par exemple, en butée avec un flasque (5) présentant une ouverture centrale (5a) pour le passage du support (1).
• Lorsque le vérin (2) est actionné, la tête de piston (2a) est logée, de manière étanche, dans la portée interne de centrage (1c). De l'air est envoyé par le canal (2c) de la tige (2b) et comprimé dans le chambrage (1a) du tube support (1). Cet air comprimé a tendance à s'échapper par les microperforations (1b) en créant, à la périphérie du tube (1), un coussin d'air (C). Ce coussin d'air, sous l'action conjuguée de la force de poussée exercée par le vérin (2), permet l'éjection du tube (1).

Given the characteristics underlying the invention, the realization of a coil is carried out as follows:

• The winding support (1) is arranged in a winder of the type illustrated in FIG. figure 2 instead of the generally used cardboard tube (T). The formation of the coil on the tube or winding support (1) therefore remains in a conventional manner. At the exit of the winder, the coil (BO) is equipped with the steel tube (1).
• The coil (BO) with the tube (1) is transferred, by any known and appropriate means, including a fully automatic manner, to an ejection station comprising in particular at least the pneumatic cylinder (2).
• The coil (BO) with the tube (1) is positioned and centered in a support cradle, for example, in abutment with a flange (5) having a central opening (5a) for the passage of the support (1).
• When the cylinder (2) is actuated, the piston head (2a) is housed, tightly, in the inner centering surface (1c). Air is sent through the channel (2c) of the rod (2b) and compressed in the recess (1a) of the support tube (1). This compressed air tends to escape through the microperforations (1b) by creating, at the periphery of the tube (1), an air cushion (C). This air cushion, under the combined action of the thrust force exerted by the cylinder (2), allows the ejection of the tube (1).

We refer to Figures 6, 7 and 8 which show the principle of ejection of the support tube (1).

After ejection of the support tube (1), a coil (BO) is obtained ( figure 6 ) whose bore (a) is completely smooth and has no mandrel.

In view of this winding process, not only is it possible to obtain a coil ready to be shipped without any mandrel, but whose bore is perfectly smooth and of round section, as opposed to certain techniques used to attempt to achieve coil without chuck.

According to the invention, the appearance of the coil is therefore strictly identical to a coil equipped with a cardboard mandrel.

For the use of the coil according to the invention, for example for its unwinding, and considering that its bore (a) is perfectly circular and smooth, it is possible to equip each of the ends of the coil thus made of nozzles manipulation, plastic for example.

• la possibilité de réaliser une bobine apte à être expédiée sans aucun mandrin;
• l'économie réalisée résultant de la suppression du tube en carton ;
• la qualité du résultat obtenu, la bobine sans mandrin ayant le même aspect qu'une bobine avec un tube en carton, y compris dans le cas d'un bobinage de film plastique en matière étirable où les forces de tension sont très importantes.

The advantages stand out well from the description, in particular one underlines and recalls:

• the possibility of producing a coil that can be shipped without any mandrel;
• the realized savings resulting from the removal of the cardboard tube;
• the quality of the result obtained, the mandrelless coil having the same appearance as a coil with a cardboard tube, including in the case of a winding plastic film winding where the tension forces are very important.

Claims (8)

A method for winding a plastic film to produce a reel,
characterized in that the film (F) is wound on a tube (1) temporarily acting as a winding mandrel; the tube (1) on which the film is wound is subjected to the action of a jack (2) whose piston head (2a) cooperates, in a sealed manner, with an end of said tube (1) for ejection in combination with a compressed air supply to create an air cushion at the outer periphery of the tube, so as to form a mandrelless coil; - The tube is reintroduced into a winding machine for a next winding. Device for implementing the method according to claim 1, characterized in that it comprises a winding tube (1) of rigid material shaped to cooperate, after winding the film, with a pneumatic jack (2) able to exert a pushing force and sending air under pressure, so as to create a cushion or an air film at the periphery of said tube (1) for its ejection so as to form a coil without mandrel. Device according to claim 2, characterized in that the winding tube (1) delimits an internal chamber (1a) in communication, on the one hand, with the outside by a plurality of microperforations (1b) formed on the periphery of said tube (1) and, secondly, with an internal centering surface (1c) shaped to receive, in a sealed manner, the head (2a) of the piston connected to a compressed air compressor. Device according to claim 3, characterized in that the internal centering surface (1c) is formed at one end of the tube (1) and is in communication with the internal chamber (1a) of said tube and with an internal channel of the head and piston rod for the injection of air. Device according to claims 2 and 4, characterized in that the head (2a) of the piston peripherally has arrangements capable of sealing after introduction of the centering surface. Device according to claim 5, characterized in that the arrangements consist of at least one O-ring (4). Device according to claim 2, characterized in that the tube (1) is made of a non-deformable rigid material, in particular steel. Plastic film spool resulting from the implementation of the method according to claim 1, characterized in that it has a totally free and smooth bore adapted to receive, at the time of its use, at least one handling endpiece.

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