REWINDING MACHINE WITH SUPPORT SYSTEM FOR REEL AND RIBBON

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a rewinding machine equipped with a support system for the reel and the ribbon-like product. In particular, the present invention relates to a method and related apparatus for producing reels of ribbon-like material, such as paper, tissue paper, nonwoven fabric, plastic film and similar products, which includes using a support system comprising a web between the rewinding machine and the unwinding roller.

BACKGROUND ART

In the reel manufacturing industry, especially large reels of ribbon-like product, winding is generated by winding the product about a support which can be a rod or a cardboard core.

The product, from a parent reel, is unwound by unwinding machines to be cut lengthwise into strips and then rewound by a rewinding machine, thus obtaining reels of different widths for further processing.

The already known systems of rewinding machines for producing reels include both the mode in which motion is transmitted to the rod and the peripheral-motion mode in which the rod is idle and rotation is imparted by at least one motorized winder roller in peripheral contact with the reel surface. For example, patent U.S. Pat. No. 4,635,867A describes a peripheral traction winding system, consisting of two motorized feeding rollers which support the reel at the bottom from the first step of starting the winding onto the rod diameter is until the final reached. Such rewinding machines are defined as having carrier rollers.

The feeding during rotation with peripheral contact is achieved by the weight force which is discharged at the contact points between reel and carrier rollers. This system has the disadvantage that the increase in weight of the reel being formed increases the pressure on the surface thereof generated on the contact line with the feeding roller, resulting in a change of thickness of the ribbon-like product. In order to obviate this drawback, other devices can be added, such as supports at the rod ends which follow the displacement during the growth in order that the load on the reel surface can be lightened, but such contrivances are not sufficient because the weights involved for large reels are of several tons. In order to produce a good quality reel in a carrier roller rewinding machine, the pressure of the contact line between the reel and a roller should not exceed 4 kN per meter, depending on the type of ribbon-like product, of its thickness and quality, and required specifications.

In order to solve the problems related to the distribution of contact pressure on the reel, solutions have been found by adopting an additional support of the reel by means of an elastic belt, such as a rubber belt.

DE patent no. 2908294 describes a rewinding machine in which there are two fixed drums arranged in a vertical alignment and a third movable drum on which a belt is wound, which in turn is wound onto one of the fixed drums, specifically onto the lower drum. The winding system provides that as the reel diameter increases, the movable roller can take new positions, while the fixed upper roller, which in a first step when the reel is small has the function of keeping the reel under control by means of a third contact point at about 120° with respect to the other two, is geometrically out of play. Disadvantageously, the reel, having reached a large diameter, cannot be stabilized by the effects of vibration resulting in a limitation of the winding speed.

In patent U.S. Pat. No. 4,746,076, a support for the reel is used by means of multiple contact points obtained with two rollers in a fixed position, a roller in a movable position, and a belt segment. Specifically, the system involves a first fixed roller with a larger diameter and a second fixed roller adjacent thereto, on which a belt is wound. The latter also winds onto a third movable outer roller so as to create a belt segment to support the winding reel. Finally, a fourth movable upper roller completes the contact point on the reel during the growth. Disadvantageously, the geometry of the system does not allow a good control of the reel when it reaches a large diameter, because precisely in that step the movable outer roller, which has an opening movement with respect to the other rollers, leaves a large segment of the reel unsupported.

The production of reels of continuous strip products, such as paper, nonwoven fabric or plastic film, requires increasingly faster speeds to meet market requirements. As a natural result, the rotation speed when the reel is wound becomes a step in which the physical limits on the dynamics, due to the density of the reel, the eccentricity thereof, and the triggering of vibrations of all rolling members are reached. For this reason, the reel needs to be supported in an even and distributed manner, and furthermore an equivalent distance should be maintained between the contact points. This feature is not achieved by the patents described above.

Patent IT-FI980131A1 describes a rewinding machine in which the carrier rollers are lowered with respect to the center of the reel and keep the contact points fairly equidistant, but do not solve the drawback of high specific pressure when supporting a large reel on the carrier rollers themselves.

There are speed limitations for the reel production when the ribbon-like product has low grammage, such as in certain cases with paper or nonwoven fabric, due to the fact that it is not possible to apply the necessary tensioning to the product to convey it stably from one roller to another.

Patent DE 675979C provides a winding between two carrier rollers between which a belt is placed and in which the carrier rollers move away from each other as the reel grows, improving the contact point and the weight distribution.

However, disadvantageously, the belt imposes the same rotation speed on the carrier rollers and prevents control over the winding features of the reel, which is known to be achieved by adjusting a speed difference between the two carrier rollers, a crucial factor in fulfilling all market requirements for reels with different winding densities.

In the machine of the aforesaid patent, the ribbon-like product is conveyed by means of two closed belt loops which are mutually supported so as to retain it over the path between the unwinder and the winder, offering the advantage of avoiding product tensioning. However, crushing between the conveyor belts can disadvantageously generate damage, e.g., in thick products, and thus change the features thereof. Finally, this method makes the machine more complex and expensive. Many ribbon-shaped products cannot be tensioned, otherwise they will take a completely different shape once the tensioning ceases. For products such as paper, nonwoven fabric, or the like, it is important for the ribbon to be conveyed with the utmost care and not undergo any changes in the machine, so that the properties of the concerned materials are preserved.

In almost all cases, the systems for conveying the ribbon-like product from the unwinding machine to the rewinding machine are created by means of rotating rollers, which can be idle or motorized for the supporting and feeding function. Therefore, it is apparent that the ribbon-like product needs to be tensioned to overcome air resistance during fast movement with all the side effects described above. The product tensioning also generates a narrowing of the width thereof with the formation of creases. The latter need devices to be eliminated, such as other motorized widening rollers which add cost and complexity to the systems.

Devices are also known in which rubberized belts are used to convey sheets or fabrics, but these applications have been limited to partial conveyance of materials with more consistency and only for short distances, not completely achieving the purpose and not solving all the drawbacks.

SUMMARY OF THE INVENTION

It is the object of the present invention to suggest a method for winding reels of ribbon-like products which allows achieving a winding adapted to maintain the product quality. Such an object is achieved as outlined below, using the peripheral winding mode in a rewinding machine of the carrier roller type and inserting a web segment such as to allow obviating the drawbacks of the prior art.

In essence, the winding method of the present invention includes using a third roller between the two carrier rollers so that a flexible web forms, with a carrier roller, a reel support segment for weight distribution. In certain embodiments, the present invention provides that the closed loop web extends up to the unwinding machine so as to also operate as a conveying means for the ribbon-like product.

The invention allows guiding the ribbon-like product through the operating units so that no change in its conditions or physical features can occur.

The invention allows reaching high production speeds without reel vibration problems.

It is another object to produce ribbon-like product reels even with low-density winding while maintaining good production speeds.

The invention allows producing ribbon-like product reels with low grammage while keeping the product stable without the formation of creases and without the need to tension the material (width reduction). The invention also allows reducing the effect of air resistance on the ribbon-like product by virtue of it being accompanied by the web.

It is another object to facilitate the passage of the ribbon-like product between the unwinding machine and the rewinding machine whenever the process is started.

The invention allows removing dust residues from the ribbon-like product.

The objects outlined above and others are achieved by a rewinding machine as defined in the appended claims, the definitions of which form an integral part of the present description.

In general terms, the rewinding machine of the invention comprises:

• • a fixed support structure which supports an unwinding unit and a rewinding unit;
  • a first independent motorized carrier roller;
  • a second independent carrier roller placed horizontally with respect to the first carrier roller;
  • a third roller, placed between the first and second carrier rollers;
  • a set of driving rollers placed along a path between the unwinding unit and the rewinding unit;
  • a web, forming at least one web loop, made of a material with an air-permeable texture, said web unwinding between the second carrier roller, the third roller, and the set of driving rollers;
  • optionally, one or more suction boxes placed under the web to retain the ribbon-like product.

A rewinding machine as outlined above is characterized in that the ribbon-like product intended for rewinding is conveyed from the zone of the unwinding unit up to the position of the third roller located between the two carrier rollers, by means of a web segment which supports the weight of the reel during the growth and the ribbon along the path.

Advantageously, the reel, being also supported on the web segment formed between the third roller and the second carrier roller, discharges its own weight over a very large surface, of about 8-10 times greater than that possibly achieved with the reel being supported only by the two carrier rollers, with the benefit of greatly reducing the specific pressure. There are several benefits as a result of the specific pressure reduction, such as: the thickness of the ribbon-like product is preserved, the reel does not sag between support points avoiding slipping between the winding turns, more speed control is achieved, and vibrations due to unstable support are not established.

Advantageously, the embodiment with the carrier rollers installed on movable supports, i.e., such as to change position, allows creating an ideal reel support geometry in the different sizes of its diameter during the growth; in particular, when the reel has a large diameter, it can benefit from supports with a wide base in favor of vibration reduction.

Advantageously, the ribbon-like product is transferred to the rewinding machine without the need to apply tensioning because the product is supported on the web, which conveys it directly. The tensioning on the product would have caused creases to occur and would have required the installation of devices to eliminate them with added cost and complexity to the system.

Advantageously, the web is wound onto the second carrier roller and the third roller, leaving the first carrier roller free to take an adjustable speed to gain control over the winding features.

Advantageously, the web facilitates the transition of the ribbon-like product from one operating unit to another, making it faster to restore the operating conditions whenever an interruption occurs.

Advantageously, the third roller is on a movable element which allows varying the width arc of the web on the reel and thus having an instrument for adjusting the support thrust thereof or for damping the natural vibrations of the reel mass.

Advantageously, using the web for conveying the ribbon-like product, a straight product path is created, with several benefits in terms of reducing the dispersion of product residues and fibers into the air, because all the bending segments that would have been present with the type of product conveyance with motorized rollers are avoided. Indeed, the bending and folding segments of the product under fast movement would have generated stress and a release of fibers into the air.

Advantageously, since the conveying web is of the air-permeable texture type, it allows applying suction boxes to the side opposite to the support surface of the ribbon-like product, thus achieving two benefits: improving the product stability on the web when conveyed and aspirating dust residues present on the product itself.

In certain embodiments, the web is made in two parts, in particular, a first loop can be made including a winding only on the second carrier roller and the third roller, and a second loop including a winding on the set of driving rollers so as to convey the product from the unwinding unit zone to the zone adjacent to the second carrier roller. This series of operations allows applying a different speed between the webs and thus benefiting from a speed adjustment between the two segments.

In particular, the invention is directed to:

• • 1) a rewinding machine for a ribbon-like product, comprising:
    • a fixed support structure which supports an unwinding unit and a rewinding unit;
    • an independent first carrier roller, movable along a direction parallel to a support surface of the rewinding machine;
    • a second independent carrier roller, movable in the opposite direction with respect to the first carrier roller;
    • a third roller, placed between the first and second carrier rollers and movable integrally with the first carrier roller or the second carrier roller;
    • a set of driving rollers placed along a path between the unwinding unit and the rewinding unit;
    • a web, forming at least one web loop, made of a material with an air-permeable texture, said web unwinding between the second carrier roller, the third roller, and the set of driving rollers;
    • optionally, one or more suction boxes placed under a lower surface of the web to retain the ribbon-like product;
  • 2) a rewinding machine according to item 1, wherein the rewinding unit comprises a fixed structure which supports a first movable structure and a second movable structure, said movable structures being movable on a plane parallel to the support surface of the rewinding machine, wherein the first movable structure supports the first carrier roller and the second movable structure supports the second carrier roller;
  • 3) a rewinding machine according to item 1 or 2, wherein an arm pivots on the rotation axis of the first carrier roller or the second carrier roller, the third roller pivoting at the distal end of the arm, wherein said arm is connected, in a point adjacent to the third roller, to an actuator, e.g., a pneumatic, hydraulic, pneumatic-hydraulic or electric actuator, to control the position register of the third roller;
  • 4) a rewinding machine according to item 2 or 3, wherein the second movable structure supports the second carrier roller and a cutting unit configured to make cuts on the ribbon-like product;
  • 5) a rewinding machine according to any one of items 1 to 5, wherein said web has a width at least equal to the width of the ribbon-like product and comprises a web guiding system which allows the web to remain in a central position;
  • 6) a rewinding machine according to any one of items 1 to 5, wherein the driving rollers comprise a tensioning roller, installed on a slide movable by means of an actuator, which keeps the web taut as a function of the displacement of the movable structures;
  • 7) a rewinding machine according to any one of items 4 to 6, wherein a suction box, having a length equal to the width of the web, is placed between the second carrier roller and the cutting unit, parallel to the roller axis, and is positioned to skim the bottom surface of the web;
  • 8) a rewinding machine according to any one of items 4 to 7, comprising two web loops, of which:
    • a first loop forms a path about the third roller, about the second carrier roller, and closes by means of diverter rollers, thus unwinding between the two movable structures,
    • a second web loop forms a support path for the ribbon-like product from the tensioning roller to a diverter roller close to the cutting unit,
    • wherein the first loop and the second loop are configured to be moved at different speeds;
  • 9) a rewinding machine according to any one of items 1 to 8, comprising a third web loop provided with suction boxes and a web guiding system, which accompanies the ribbon-like product immediately downstream of the unwinding point from the reel (BSV) up to near a web loop;
  • 10) a rewinding machine according to any one of items 4 to 9, wherein at least one of said web loops is operatively coupled to a presser belt so that the ribbon-like product is kept sandwiched between web loop and presser belt up to near the cutting unit;
  • 11) a method of rewinding a ribbon-like product unwound from a reel and rewound onto a second reel, comprising the steps of:
  • a) providing a rewinding machine according to any one of items 1 to 10,
  • b) as the winding of the ribbon-like product progresses to form the reel, increasing the mutual distance between said first carrier roller and said second carrier roller, until a distance is created between said carrier rollers so that the third roller can be introduced therebetween,
  • c) taking said third roller from a lowered position to a contact position with the reel, so as to create a segment of web for supporting the reel,
  • d) continuing to increase the mutual distance between said first carrier roller and said second carrier roller and thus the width of the support segment of web until the winding of the reel is completed;
  • 12) a method according to item 11, wherein the rotation speed of the first carrier roller is different from the rotation speed of the second carrier roller;
  • 13) a method according to item 11 or 12, wherein, when the rewinding machine is as defined in item 8, the speed of the first loop of the web is different from the speed of the second loop of the web.

BRIEF DESCRIPTION OF THE FIGURES

These and further advantages and embodiments of the present invention will be better understood from the following description with the aid of the accompanying drawings, provided by way of non-limiting example, in which:

FIG. 1 shows a side view of a rewinding machine according to the invention in an operating sequence in a step of starting the winding;

FIG. 2 is a side view of the rewinding machine in FIG. 1 in an operating sequence in a step of ending the winding;

FIG. 3 shows a detail of the carrier rollers and the third roller of the rewinding unit in a step of the advanced winding of a reel;

FIG. 4 shows a side view of a different embodiment of the rewinding machine of the invention in an operating sequence;

FIG. 5 shows a side view of the rewinding machine according to a different embodiment in a step of ending the winding;

FIG. 6 shows a side view of the rewinding machine according to a yet different embodiment in a step of ending the winding;

FIG. 7 shows a side view of the rewinding machine according to a further embodiment in a step of ending the winding;

FIG. 8 shows a detail of the carrier rollers and the third roller of the rewinding unit in FIG. 7 in a step of the advanced winding of a reel.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the figures from 1 to 3, a rewinding machine indicated by reference numeral 1 will first be described as a whole, comprising an unwinding unit SV and a rewinding unit RB of the carrier roller type.

The rewinding unit RB consists of a fixed structure 12 and a first 9 and a second 8 movable structure, which are movable preferably on a horizontal plane. Said movable structures 8, 9 support a first carrier roller 2 and a second carrier roller 4, respectively. The first movable structure 9 supports the first carrier roller 2. An arm 3.1 pivots on the rotation axis of the first carrier roller 2, a third roller 3 pivoting on the distal end of the arm. An actuator 3.2, e.g., a pneumatic or hydraulic actuator, is installed to control the position register of the third roller 3 by acting, e.g., by means of a piston, on a point of the arm 3.1 adjacent to the third roller 3.

The second movable structure 8 supports the second carrier roller 4 and a cutting unit 7, of the type known in the industry, consisting of a series of circular blades to make cuts on the ribbon-like product N.

A web, at least as wide as the ribbon-like product N, closed in a loop and made of a material with an air-permeable texture (e.g., a woven synthetic fiber material or a set of coupled belts), unwinds on a set of driving rollers 110 between the rewinding unit RB and the unwinding unit SV, so that it acts as a conveyor for the ribbon-like product N. A web guiding system 13, not described here because known from the prior art, allows the web 10 to remain in the center of the line.

In certain embodiments, the web is made of a polymer fiber woven into warp and weft. For example, the polymer fiber can incorporate carbon fibers, or it can be PEEK (polyetheretherketone) or PPS (polyphenylene sulfide) fiber to achieve antistatic properties.

The driving rollers 110 comprise a tensioning roller 14, installed on a slide 14.1 movable by means of an actuator, which keeps the web 10 taut as a function of the displacement of the movable structures 8 and 9.

A suction box 6, having a length equal to the width of the web 10, is placed between the second carrier roller 4 and the cutting unit 7, parallel to the roller axis. The suction box 6 is positioned to skim the bottom surface of web 10.

The web 10 extends as follows: from the unwinding unit SV, in particular between the tensioning roller 14 to near the cutting unit 7, the web 10 travels along a straight segment which coincides with the path of the ribbon-like product N, after that the web 10, by means of the diverter rollers 11 (belonging to the set of driving rollers 110), passes under the cutting unit 7 until it winds about the second carrier roller 4, the third roller 3 and then returns, under the straight segment described above, to the tensioning roller 14.

From the unwinding unit SV, where the members for rotating the reel BSV adapted to unwind it are not shown for simplicity of the drawing because they are known from the prior art, the ribbon-like product N is accompanied by the support rollers 15 up to tangency with web 10. Other suction boxes 6 are installed in the straight segment of web 10, on the side opposite to the support surface of the ribbon-like product N, in a number which varies as a function of the specifications of the processed ribbon-like strip product N. All suction boxes 6 are connected by means of pipes to vacuum means, e.g., a pump to generate an air vacuum, thus allowing the suction boxes 6 to apply a retaining force to the product itself.

It is easy to understand the operation of the conveying function of the web 10 without affecting, modifying, or stressing the ribbon-like product N. Furthermore, the suction air for the retaining force on the ribbon product N also performs a function of removing dust particles from the ribbon-like product N, so as to prevent them from being released into the environment.

During the step of rewinding, the segment of the web 10 between the third roller 3 and the second carrier roller 4, shown in FIG. 3 with reference numeral 10t, is of critical importance for supporting the reel B being formed. As mentioned above, it is easy to see the beneficial effect of discharging the weight of the reel B especially when it reaches a large diameter.

The operation of the rewinding process is described below.

The movable structures 9, 8 of the carrier rollers 2, 4 are positioned at a short distance so as to contain the small diameter of the reel B at the start of the winding, while the third roller 3 is lowered so that it does not interfere with the second carrier roller 4.

A rider roller 5, as referred to in jargon because known from the prior art, is placed at the top of the reel B with the function of stabilizing it and accompanying its growth in diameter.

As winding progresses and thus as the diameter of the reel B grows, the carrier rollers 8, 9 are progressively moved symmetrically away from each other by an extent determined by the production specifications.

As soon as the sufficient space is created, the third roller 3 is lifted by the actuator 3.2 and inserted between the carrier rollers 2, 4, thus moving the web segment 10t supporting the reel B (FIG. 3).

Advantageously, the third roller 3, being aboard the movable structure 9 which has a displacement away from the second carrier roller 4, allows increasing the web segment 10t proportionally to the increase in diameter of the reel B and thus in its weight. By means of the arm 3.1, the third roller 3 can also apply an additional pressure or possibly modify the web segment 10t, as a function of the establishment of critical speeds which naturally occur with masses at high rotation speed.

The first carrier roller 2, remaining independent from the speed of the second carrier roller 4, can be adjusted while winding to create a reel B with different density according to the required specifications.

FIG. 4 shows a different embodiment in which two web loops are obtained, the first loop 10a of which forms a path about the third roller 3, about the second carrier roller 4, and closes by means of diverter rollers 11, thus unwinding between the two movable structures 8, 9. A second web loop 10b forms a support path for the ribbon-like product N from the tensioning roller 14 up to a diverter roller 11 close to the cutting unit 7. In this embodiment, the possibility to diversify the speed between the two web loops 10a, 10b is advantageously obtained, in order to manage the tensioning of the ribbon-like product N as a function of the cutting process of the cutting unit 7.

FIG. 5 shows a different embodiment yet, entirely similar to that in FIGS. 1 and 2, but further comprising a third web loop 10c, provided with suction boxes 6 and a web guiding system 13, which accompanies the ribbon-like product N immediately downstream of the unwinding point from the reel BSV to near the first web loop 10, where a support roller 15 promotes the change of direction thereof.

In such an embodiment, as shown by the arrow in the figure, the unwinding of the reel BSV takes place in the opposite direction, i.e., counterclockwise, with respect to the embodiment in FIG. 1.

FIG. 6 shows a further embodiment, similar to that in FIG. 5, but in which both the first and the third web loops 10, 10c are operatively coupled to a presser belt 20 so that the ribbon-like product N is kept sandwiched between the web 10, 10c and the presser belt 20 up to near the cutting unit 7. Although FIG. 6 shows the suction boxes 6, the latter could also be omitted by virtue of the retaining action applied by the presser belt 20.

FIGS. 7 and 8 show a yet further embodiment, comprising a first, a second and a third web loop 10a, 10b, 10c as described above. In this embodiment, the third roller 3 pivots on the distal end of an arm 3.1, which pivots on the rotation axis of the second carrier roller 4. An actuator 3.2, e.g., a pneumatic, hydraulic, hydraulic-pneumatic or electric actuator, is installed to control the position register of the third roller 3 by acting, e.g., by means of a piston, on a point of the arm 3.1 adjacent to the third roller 3.

Of course, the features described in connection with the aforesaid embodiments can be combined in manners other than that described in the figures. For example, the presser belt 20 can also be coupled to the machine in FIGS. 1 and 2, adapting it to a uniquely horizontal shape.

Similarly, the third roller 3 can also be made integral with the second movable support 8 in the machine in FIG. 1 or in those in FIG. 5 or 6.

All steps of loading the winding spindle between the carrier rollers of the rewinding unit RB or unloading the reel B when winding is completed have not been shown to simplify the drawings because they are common systems of already known machines.

Finally, the aforesaid advantages remain safeguarded even in the presence of variations or modifications of a practical application nature which can be made by those skilled in the art to a rewinding line as described above, while remaining within the scope of protection defined by the following claims.