Patent Application
20170253450
The present disclosure relates to an apparatus for the production of convolutely wound rolls of web material. The present disclosure more particularly relates to an improvement to the leading edge of the winding cradle of a surface winding machine used for the production of rolls of convolutely wound web material wound about a core. The improved leading edge device significantly reduces the slippage of the core after its initial insertion between the concave cradle and upper winding roll of a surface winder.
Paper is normally produced by continuously running machines that, through the delivery of a stock of cellulose fibers and water distributed from head-boxes, generate a ply of cellulose material on a forming fabric. The ply is typically dried and wound in reels having a very large diameter (known in the industry as parent rolls). These reels are subsequently unwound and rewound about a core material to form logs having a smaller diameter. The logs are subsequently divided into rolls having dimensions that are equal to the dimension of the end product. Paper products such as rolls of bath tissue, kitchen towels, or other tissue paper products are normally manufactured with this process.
Generally, rewinding machines (or rewinders) are used to produce convolutely wound rolls or “logs” of web material wound about a core. Rewinders are used to convert the large parent rolls of paper into retail sized rolls and bathroom tissue and paper towels. These rewinding machines typically wind a predetermined length of web material about a tubular winding core normally made of cardboard. These rolls, or logs, are then each cut into a plurality of smaller-size rolls intended for commercial sale and consumer use. The tubular winding core section remains inside each convolutely wound roll of web material. In both cases the end product contains a tubular core made of material that is different from that forming the web material.
Rewinding machines are generally divided into two categories depending on the manner in which the winding movement is provided. A first type of rewinding machine, known as a central spindle rewinding machine (or center winder), provides a spindle supported on support elements disposed between a pair of side walls. The center winder receives a tubular winding core on which the roll or log is formed by means of rotation of the spindle which, for this purpose, is typically associated with a drive means. The winding movement of the web material about the core is provided centrally by the spindle.
A second type of rewinding machine, known as a surface rewinding machine (or surface winder), uses the rotational movement of the tubular core (on which the roll or log is formed) provided by peripheral members in the form of rollers or rotating cylinders and/or belts. The roll or log is kept in contact with the rollers or rotating cylinders and/or belts during log formation. Exemplary surface winders are disclosed in U.S. Pat. Nos. 3,630,462; 3,791,602; 4,541,583; 4,723,724; 4,828,195; 4,856,752; 4,909,452; 4,962,897; 5,104,155; 5,137,225; 5,226,611; 5,267,703; 5,285,979; 5,312,059; 5,368,252; 5,370,335; 5,402,960; 5,431,357; 5,505,405; 5,538,199; 5,542,622; 5,603,467; 5,769,352; 5,772,149; 5,779,180; 5,839,680; 5,845,867; 5,909,856; 5,979,818; 6,000,657; 6,056,229; 6,565,033; 6,595,458; 6,595,459; 6,648,266; 6,659,387; 6,698,681; 6,715,709; 6,729,572; 6,752,344; 6,752,345; and 6,866,220. Additionally, exemplary surface winders are discusses in International Publication Nos. 01/16008 A1; 02/055420 A1; 03/074398 A2; 99/02439; 99/42393; and EPO Patent Application No. 0514226 A1.
Generally, a surface winder is comprised of three principle winding rolls that perform the surface winding process. These rolls are known to those of skill in the art as the first winding roller (or upper winding roll (UWR)), the second winding roller (or lower winding roll (LWR)), and the third winding roller (or rider roll (RR)). These respective rolls are named due to where, or how, they contact a winding log. The UWR and LWR contact the winding log on the upper and lower portions respectively and the RR “rides” on the upper portion of the winding log as it increases in diameter as web material is wound thereabout. The core enters the surface winder and is typically adhesively attached to a web material to be wound thereabout in a region of compression disposed between the UWR and LWR. The winding log (core plus any web material convolutely wound thereabout) is initially rotated by the UWR in a region disposed between the UWR and a stationary core cradle. The winding log is then rotationally translated to a region disposed intermediate the rotating, but stationary, UWR and LWR (known as the winding nest region). The RR contacts the surface of the rotating winding log in the winding nest region and translates away from the UWR and LWR as web material continues to be convolutely wound about the winding log (core plus all web material convolutely wound thereabout).
In an exemplary surface wind system, a web material is convolutely wound about a paperboard core of 1.5″ to 1.7″ diameter and of a length that corresponds to the width of the tissue parent roll which comes from the paper machine, usually in width from 65″ to 155″.
However useful, current surface winders do have known limitations. As shown in
First, the entry portion of the cradle positioned at a fixed point disposed orbitally about the UWR typically has a smooth surface. An exemplary entry point is shown in
Second, the glue-laden core is targeted to contact the web material in contact with the UWR at a predetermined location by the requirements of the winding process. Typically the targeted contact location on the web material is disposed immediately adjacent a perforation between two separable sheets of web material. If this targeted attachment location changes, several unfavorable results can occur in the early stage formation of the convolutely wound material.
For example, if the web attachment point occurs at a point removed backwards from the region near the perforation (e.g., behind the perforation), any excess leading web material will ‘fold-back’ upon the core and overlap the region of actual attachment of the web material to the core. This causes a consumer undesirable and unattractively wound product.
If the web attachment point occurs at a point removed forwards from the region near the perforation (e.g., ahead of the perforation), the web material can fail to attach to the core. This can result in the deposition of the adhesive disposed upon the core material (e.g., the so-called core glue) upon the manufacturing equipment. Ultimately, this can result in a build-up of core glue upon the surfaces of the process equipment and result in a process shut-down. Not only will the web material need to be re-threaded though the converting equipment, but adhesive will also have to be manually removed from the surfaces of the rewinding equipment such as the winding cradle and UWR.
Thus, there is a clearly defined need to increase the acceleration of the core surface speed at the point of insertion of the core into the winding cradle to prevent the drawbacks observed by current surface winding equipment that meets current manufacturing financial and processing targets.
The present disclosure provides for an improvement to a surface winder for winding a web material around a core having a radius, R, to obtain a log. The surface winder comprises a glue applicator for dispensing glue onto the core, a core inserter for transporting and inserting the core provided with the glue disposed thereon into a winding cradle defined at a top by an upper winding roller, supplied from above with the web material directed towards the winding cradle at a velocity, v, and at a bottom by a concave cradle associated downstream to a lower winding roller. The surface winder further comprises a third oscillating roller arranged above the lower winding roller. The upper winding roller, the lower winding roller, and the third oscillating roller each have a respective axis parallel to each other and perpendicular to the feeding direction of the web material and cooperating with each other downstream of the winding cradle in order to wind the web material around the core to obtain the log. The concave cradle comprises an introductory portion. The introductory portion of the concave cradle comprises a leading edge device. The leading edge device has a surface for contacting the core and has a texture provided thereto.
The present disclosure also provides for a leading edge device for incorporation into an introductory portion a concave cradle. The concave cradle is associated with an upper winding roller of a surface winder to form a winding cradle for winding a web material having a velocity, v, around a core having a radius, R, inserted therein to obtain a log. The leading edge device has a surface having a texture provided thereto for contacting the core.
An exemplary embodiment of a prior art rewinder is shown in
The winding head of the exemplary prior art rewinder is generically indicated with 1. In this exemplary embodiment, the winding head of the rewinding machine comprises a first winding roller 3 (also referred to herein as upper winding roll 3) with a rotation axis 3A, a second winding roller 5 (also referred to herein as lower winding roll 5) rotating about a rotation axis 5A and a third winding roller 7 (also referred to herein as rider roll 7) rotating about a third rotation axis 7A. A nip 11 is defined between the two winding rollers 3 and 5 for passage of the web material, having a speed, v, which can be equal to the surface speed of upper winding roll 3, wound about a core A.
In some embodiments the axis 3A of the first winding roller 3 is fixed with respect to a load bearing structure (not shown) of the rewinder. In other embodiments the axis 3A can be moving with respect to the load bearing structure (not shown).
In some embodiments the axis 5A of the second winding roller 5 is movable. In some embodiments the axis 5A can be moved to produce logs with a winding core A. In other embodiments, the rotation axis 5A of the second winding roller 5 can be movable in a controlled manner also during each winding cycle of logs upon a core A having a variable diameter. Ideally, the axis 5A of the second winding roller 5 can be movable to adapt the machine to winding cores A or mandrels having different diameters. In any regard, the first winding roller 3 can have a moving axis 3A for the same reasons indicated above. Further, both the winding rollers 3 and 5 can be movable and adjustable.
The third winding roller 7 is advantageously carried, for example, by a pair of arms 9 pivoting with a reciprocating movement according to the double arrow f9 about a pivoting axis 9A. The movement according to the double arrow f9 enables the third winding roller 7 to move toward or away from the first winding roller 3 and second winding roller 5 according to the diameter of the log L during the step of formation inside the winding cradle defined by the three winding rollers 3, 5 and 7.
The exemplary prior art rewinding machine 1 can be provided with a concave cradle 41. The concave cradle 41 is in actual fact preferably formed by a series of mutually parallel shaped plates, only one of which is visible in the drawing and the others being superimposed thereon. The various shaped plates all have a concave edge forming a concave surface for rolling of the winding cores.
The winding cores A are fed along a feeder 47. Single winding cores A can be picked up by a core inserter 49 after a longitudinal line of glue has been applied thereto by a glue applicator 51. The machine in this arrangement has substantially the same structure and operation as that described in U.S. Pat. No. 5,979,818 and therefore the operating cycle will not be described in detail.
As shown in
In this regard, movable finger 28 can emanate from a centroid of cam housing 34 in a manner that causes cam housing 34 to orbit about the longitudinal axis 38 of cam-controlled core inserter 10. As cam housing 34 orbits about the longitudinal axis 38 while disposed in contacting and moveable engagement with cam housing 34, cam housing 34 can define the motion of movable finger 28 relative to the longitudinal axis 38, fixed finger 22, and winding core A. Without desiring to be bound by theory, it is believed that by providing a cam housing 34 system to control the movement of movable finger 28 of cam-controlled core inserter 10 can provide a more reliable and consistent contact and release system for the insertion of a winding core A into the introductory portion 12 of winding cradle 13.
As shown in
Returning again to
Interaction between the concave cradle 41 and the moving member 21 is permitted by the fact that the former has a comb shaped structure formed by a plurality of parallel plates. In this way, the pads 23 of the moving member 21 can pass between adjacent plates and enter the feed channel of the winding cores A formed between the concave surface 41A of the cradle 41 and the cylindrical surface 3B of the winding roller 3.
The concave cradle 41 can be supported rotating about the rotation axis 21C of the moving member 21. The moving member passes from an idle position to an operating position by pivoting about the rotation axis 21C. Pivoting can be controlled by a piston-cylinder actuator.
Moving member 21 can be provided with a reciprocating oscillatory or rotary movement around said axis. The moving member 21 rotates in clockwise direction to come into contact with the web material N and pinch it against the cylindrical surface of the winding roller 3 and perform severing of the web material N.
As mentioned previously, single winding cores A are picked up by a core inserter 49 after a longitudinal line of glue has been applied thereto by a glue applicator 51. The core inserter 49 translates the winding core A having glue disposed thereon to a point of entry into the introductory portion 12 of the surface rewinding machine disposed between the upper winding roll 3 having a web material N disposed about at least a portion thereof and the concave cradle 41. The region disposed between concave cradle 41 and upper winding roll 3 is referred to herein as winding cradle 13. The region disposed between leading edge device 14 and upper winding roll 3 forms the introductory portion 12 of winding cradle 13. While it is possible for web material N to have a velocity, v, that is different from the surface velocity of upper winding roll 3 about its longitudinal axis 3A, for purposes of discussion herein, it can be presumed that the velocity, v, of web material N is the same as the surface velocity of upper winding roll 3 about its longitudinal axis 3A.
As shown in
As shown in
One of skill in the art will understand that when rolling of winding core A happens without slipping, the point of contact of winding core A has zero linear velocity relative to the surface 15 of leading edge device 14. When slipping (with or without rolling) of the winding core A occurs, the point of contact of winding core A with the surface 15 of leading edge device 14 has a non-zero linear velocity relative to the surface 15 of leading edge device 14. As the winding core A essentially (or effectively) slides along (or upon) the surface 15 of leading edge device 14, kinetic friction, f, eventually reduces the linear (e.g., non-rotational) velocity of winding core A relative to the surface 15 of leading edge device 14. This frictional force, f, also causes the winding core A to start rotating about its center of mass (cm). The linear velocity along the surface 15 of the leading edge device 14 of the winding core A decreases and the angular velocity, w, of winding core A increases until the non-slip condition vcm=Rω is met. Then winding core A effectively rolls upon the surface 15 of leading edge device 14 about its center of mass without (or with reduced) slipping.
In other purely mechanical terms, the linear velocity, v, of the winding core A must always equal the rate of rotation, ω, of the winding core A multiplied by the radius, R, of the winding core A from the center of rotation to the point of contact of winding core A with upper winding roll 3. If the magnitude of the linear velocity at the edge of the rotating winding core A does not equal the magnitude of the linear velocity of the center of rotation of the rotating winding core A, then there must be slipping at the point of contact of winding core A with upper winding roll 3 or the surface 15 of leading edge device 14. This results in the linear, non-rotating (i.e., translational) movement of winding core A relative to the surface 15 of leading edge device 14 because the center of rotation/mass of the winding core A must move faster than the rotation of upper winding roll 3 can move it. In other words, when winding core A experiences pure translational motion, all of its points move with the same velocity as the center of mass (e.g., in the same direction and with the same speed (v=vcm). The force of friction, f, from the surface 15 of leading edge device 14 is the only force acting upon the surface of winding core A to cause the winding core A to reduce the translational velocity, v, and increase the rotational velocity of winding core A to match the surface speed of upper winding roll 3 and web material N in contacting engagement therewith (e.g., in the rewinder described herein—also having a velocity v).
Mathematically stated, at the point of insertion of the winding core A into the introductory portion 12 of winding cradle 13 slipping and rolling forward provides vcm<Rω. Thus, the path of winding core A through the introductory portion 12 of winding cradle 13 forms a prolate (contracted) cycloid because it is traced out to points on the surface of the generating circle that is slipping while rolling with a velocity of vcm<Rω.
Therefore, one of skill in the art would understand that it can be desirable to provide the winding core A with a rotational velocity (i.e., a rolling motion) at the point of contact with upper winding roll 3 and the surface 15 of leading edge device 14. In this way, the rolling of winding core A becomes a combination of both translational and rotational motion. Thus, when the winding core A experiences pure rotational motion about its center of mass, all of its points move at right angles to the radius, R, in a plane perpendicular to the axis of rotation, so that points on opposite sides of the axis of rotation of winding core A move in opposite directions, and move with a speed proportional to radius (v=Rω), so that the center of mass does not move (since R=0) and points on the outer radius of winding core A move with speed v=Rω, and move in a circle centered on the axis of rotation (also the center of mass).
As shown in
By way of non-limiting example, as shown in
Further, each protuberance can have any geometry that may be required to reduce the slippage between a respective winding core A and the surface 15A of leading edge device 14A. For example, each protuberance can be provided as a pin extending from the surface 15A of leading edge device 14A. Alternatively, each protuberance can be provided as a polyhedron having a shape that is a pyramid, a cylinder, a cone, a truncated cone, a sphere, a prism, an ellipsoid, and/or combinations thereof. Clearly, one of skill in the art will recognize that the plurality of protuberances can be provided as combinations thereof.
As shown in
Any dimensions and/or values disclosed herein are not to be understood as being strictly limited to the exact dimensions and/or numerical values recited. Instead, unless otherwise specified, each such dimension and/or value is intended to mean both the recited dimension and/or value and a functionally equivalent range surrounding that dimension or value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention. To the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
| Number | Date | Country | |
|---|---|---|---|
| 62303448 | Mar 2016 | US |
