Method and Apparatus For Producing Coreless Roll Products

Abstract

A coreless log of convolutely wound web material is formed by directing the web around an applicator roller that is in contact with a first surface of the web. An additive is transferred from a supply roller to the applicator roller over a first distance of the web and stopped over a second distance of the web. The web is directed around at least one further roller that is in contact with the second surface of the web that is opposite the first surface. The web is then wound around an elongated mandrel. The first distance of the web comprises a first set of windings nearest the center of the log, and the second distance of the web comprises a second set of windings wound around and extending radially outward from the first set of windings. The mandrel may then be removed to form the coreless log.

Claims

1. A rewinder for winding a web of material about a mandrel into a roll of convolutely wound web material, the rewinder comprising: a first winding drum; a second winding drum opposite the first winding drum; an applicator roller configured to engage a first surface of the web; at least one further roller opposite the applicator roller configured to engage a second surface of the web that is opposite of the first side of the web, the at least one further roller being configured to direct the web between a nip formed between the upper winding drum and the lower winding drum in which the roll of convolutely wound web material is wound; a supply roller opposite the applicator roller, the supply roller being configured to meter a supply of an additive to the applicator roll; and wherein the applicator roller is configured to apply the supply of the additive to the first side of the web over a first distance of the web material and the applicator roller is configured to cease applying the supply of the additive to the first side of the web over a second distance of the web material, wherein when the web is wound around the mandrel into the roll, the first distance of the web material comprises a first set of windings nearest the center of the roll, and wherein the second distance of the web material comprises a second set of windings wound around the first set of windings and extending radially outward from the first set of windings; and wherein when the web is wound around the mandrel into the roll, the mandrel is removable from the roll after the roll is formed.

2. The rewinder of claim 1 wherein the supply roller is an anilox roller.

3. The rewinder of claim 2 further comprising a doctor chamber configured to meter the additive onto a peripheral surface of the anilox roller.

4. The rewinder of claim 1 wherein the at least one further roller comprises a draw roller.

5. The rewinder of claim 1 wherein the supply roll is configured for pivoting motion relative to the applicator roller between a supplying position and withholding position, wherein in the supplying position, the supply roller pivots sufficiently adjacent to the applicator roller to meter the supply of the additive to applicator roller over the first distance of the web material and wherein in the withholding position, the supply roller pivots sufficiently away from the applicator roller so as to withhold the supply of the additive from the supply roller to the applicator roller over the second distance of the web.

6. The rewinder of claim 5 wherein a source of the supply of the additive is configured to pivot together with the supply roller between the supplying position and the withholding position of the supply roller.

7. The rewinder of claim 5 wherein the supply roller is one in a plurality of supply rollers each opposite the applicator roller and configured to meter the supply the additive to the applicator roller.

8. The rewinder of claim 1 wherein the applicator roller and the supply roller are configured for pivoting motion together relative to the web between a supplying position and withholding position, wherein in the supplying position, the applicator roller pivots sufficiently adjacent to the first side of the web to apply the supply of the additive to applicator roller over the first distance of the web material and wherein in the withholding position, the applicator roller pivots sufficiently away from the first side of the web so as to cease applying the supply of the additive over the second distance of the web.

9. The rewinder of claim 8 wherein a source of the supply of the additive is configured to pivot together with the applicator roller and the supply roller between the supplying position and the withholding position of the applicator roller and the supply roller.

10. The rewinder of claim 8 wherein the supply roller is one in a plurality of supply rollers each opposite the applicator roller and configured to meter the supply the additive to the applicator roller.

11. The rewinder of claim 1 further comprising a secondary applicator opposite the applicator roller configured to engage the second side of the web.

12. The rewinder of claim 11 wherein the secondary applicator includes an actuator, the actuator is configured to actuate the secondary applicator to engage the second side of the web during the first distance of the web material and the actuator is configured to disengage from the second side of the web over the second distance of the web material.

13. The rewinder of claim 11 wherein the secondary applicator includes a brush operatively connected with the actuator.

14. The rewinder of claim 1 wherein the additive comprises at least one of a hole reinforcement agent, aqueous solutions of adhesive, aqueous solutions of polyanions, solutions of polycations, aqueous solutions of cationic starches, aqueous solutions of anionic starches, aqueous solutions or dispersions of inorganic cationic fillers, and aqueous solutions or dispersions of inorganic cationic nanofillers.

15. (canceled)

16. A method of forming a log of convolutely wound web material, the web material comprising a first surface and an opposite second surface, the method comprising the steps of: a. directing the web material around an applicator roller, wherein the applicator roller is in contact with the first surface of the web material; b. metering an additive onto a peripheral surface of a supply roller; C. transferring the additive from the supply roller to the applicator roller over a first distance of the web material; d. ceasing to transfer the additive from the supply roller to the applicator roller over a second distance of the web material; e. directing the web material around at least one further roller, wherein the at least one further roller is in contact with the second surface of the web material; f. winding the web material around an elongated mandrel to form the log of convolutely wound web material, wherein the first distance of the web material comprises a first set of windings nearest the center of the log, and wherein the second distance of the web material comprises a second set of windings wound around the first set of windings and extending radially outward from the first set of windings; and g. removing the mandrel from the log.

17. The method of claim 16 wherein the supply roller is an anilox roller.

18. The method of claim 17 wherein the step of metering the additive comprises metering the additive onto a peripheral surface of the anilox roller with a doctor chamber.

19-32. (canceled)

33. A method of installing an additive applicator on a rewinder, the method comprising: removing an upper outfeed draw roller from the rewinder; installing an applicator roller in place of the upper outfeed draw roller; adjacent to the applicator roller, installing the additive applicator, wherein the additive applicator is adapted and configured to alternatingly transfer an additive from a supply roller to the applicator roller over a first distance of a web material passing through the rewinder and cease to transfer the additive from the supply roller to the applicator roller over a second distance of the web material such that when the web material is directed through the rewinder and wound around an elongated mandrel to form a log of convolutely wound web material, the first distance of the web material comprises a first set of windings nearest the center of the log, and the second distance of the web material comprises a second set of windings wound around the first set of windings and extending radially outward from the first set of windings.

34. The method of claim 33 wherein the supply roller is an anilox roller.

35. The method of claim 34 wherein the additive applicator comprises a doctor chamber adapted and configured to meter the additive onto the anilox roller.

36-51. (canceled)

Description

DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is a schematic side elevation view of an exemplary rewinder.

[0008] FIG. 2 is a schematic side elevation view of the rewinder of FIG. 1 showing additional detail of an additive applicator mounted adjacent to outfeed draw rollers of the rewinder.

[0009] FIG. 3 is a partial, enlarged side elevation view of the rewinder from detail area 3-3 of FIG. 2 showing additional detail of the additive applicator.

[0010] FIG. 4 is a partial, enlarged perspective view of the additive applicator of FIG. 3.

[0011] FIG. 5 is a plan view of an embodiment of the additive applicator of FIG. 3.

[0012] FIG. 6 is a plan view of an alternate embodiment of the additive applicator of FIG. 3.

[0013] FIG. 7 is a schematic view of a web material after passing the additive applicator of FIG. 2.

[0014] FIG. 8 is a side cross sectional view of a log after passing the additive applicator of FIG. 2.

[0015] FIG. 9 is a partial, enlarged side elevation view of the rewinder similar to detail area 3-3 of FIG. 2 but showing additional detail of an additive applicator and secondary applicator.

DETAILED DESCRIPTION

[0016] The exemplary rewinder 10 for winding coreless products includes an upper winding drum 12 and a lower winding drum 14, and optionally may include a rider roller. The web 16 approaches the upper winding drum 12 from above and wraps around the upper winding drum in a web winding region 18 formed between the upper winding drum, the lower winding drum 14, and if applicable, the rider roller. The web 16 may be fed to the upper winding drum via one or more outfeed rollers, which may comprise an upper outfeed roller 22 and a lower outfeed roller 24. A curved rolling surface 26 may be used to guide a winding mandrel 28 into the winding region 18 during web transfer and then guide the rolling log 30 to the winding region. Preferably, the winding mandrel is a reusable mandrel with dimensions similar to a typical carboard core, is substantially axially elastic, and is comprised of a material having a tensile yield strength divided by elastic modulus greater than 2.0%.

[0017] The additive applicator 40 may be provided in the rewinder in a location typically proximate to the location of the upper or first outfeed draw roller 22 in a typical or conventional rewinder such as shown in FIG. 1. In a typical or conventional rewinder, the upper or first outfeed draw roller 22 may be a pivoting roll in the rewinder's lower draw unit. In the configuration described below, the applicator roller 42 occupies the location of the upper or first outfeed draw roller 22, or in the case of a retrofit, first outfeed draw roller 22 is replaced with the applicator roller 42. This location is preferred for application of the additive from the additive applicator 40 as the additive may be applied from the additive applicator on a side of the web 16 that does not contact any other rollers, and the additive may be applied to the side of the web which becomes wound to form the interior of the roll of finished product. The additive applicator 40 provides the additive to a leading edge 43A (or near the leading edge) and to a first portion 43B of the web that forms the first set of windings around the mandrel 28 after web transfer. As mentioned above, the additive may be used to facilitate removal of a winding mandrel 28 from the central hole of the log 30, improve the appearance of the central hole, stabilize the central hole, help the central hole retain its shape, and/or facilitate the central hole returning to a round shape by a consumer if the roll is a compressed roll format or if the hole has become mis-shapen.

[0018] In one aspect, the additive applicator 40 includes a supply roller 44 that alternatingly transfers and ceases to transfer the additive to the applicator roller 42. In one aspect, as shown in the drawings by way of a non-limiting example, the supply roller 44 may be an anilox roller, and the additive may be supplied to the anilox roller 44 from a doctor chamber 46. Thus, the additive is transferred from the doctor chamber 46 to the applicator roller 42 with the anilox roller 44, and applied to the web 16 with the applicator roller 42. The applicator roller may be covered with a nitrile-based compound, a polyurethane-based compound, or another suitable elastomeric material. The anilox roller 44 may have a cell volume in the range of around 10-60 cubic centimeters per square meter. In some applications an anilox roller cell volume in the range of 40-60 cubic centimeters per square meter may be preferred. The applicator roller 42 may be driven at a rotational speed such that its surface speed is the same as that of a first outfeed draw roller in a conventional rewinder, that is to say, at or near the speed of the web as dictated by desired tension or draw settings. The supply roller 44 may be driven at a rotational speed that is a percentage of the rotational speed of the applicator roller 42, for example 10%, 20%, or up to and including 100% of the rotational speed of the applicator roller 42, depending on the viscosity and other properties of the additive. The rotational speed of the supply roller may be varied with web speed, either increased as web speed increases, or decreased as web speed increases, depending on behavior of the web and/or the additive. Alternatively, the applicator roller may apply the additive directly to the mandrel instead of the web. If the additive is applied directly to the mandrel, the additive may be a liquid, a solid, or a film. In another aspect, spray guns or another type of applicator may transfer and cease to transfer the additive from a supply of the additive to the supply roller.

[0019] The supply roller 44 may be configured to intermittently supply the additive to the applicator roller 42, which in turn intermittently applies the additive to the web 16 and/or mandrel 28, as the case may be. As shown in the drawings, the supply roller 44 (comprising an anilox roller) and the doctor chamber 46 are mounted to a subplate 48. The subplate 48 is operatively pivotally mounted to a structure 50 of the rewinder 10 adjacent the applicator roller 42. The applicator roller 42 is arranged in a position above the lower outfeed draw roller 24. In one aspect, for instance, a retrofit of an existing rewinder, the upper outfeed draw roller 22 typically found on a rewinder may be replaced with the applicator roller 42, and the additive applicator 40 installed adjacent thereto in a manner as described herein. The subplate 48 may be oscillated between an application position and an idle position with an actuator 52, for example, an electric movement unit comprising an electric cylinder controlled by a servo motor, or alternatively a pneumatic actuator. A mirror image subplate and actuator may be provided on the opposite side of the rewinder, such that both the operator side and the drive side of the rewinder each have a subplate and actuator.

[0020] When in the application position of the subplate 48, the anilox (supply) roller 44 may be moved into position to apply the additive to the applicator roller 42. In the application position of the subplate 48, the anilox (supply) roller 44 engages with the applicator roller 42 so as to allow the applicator roller to apply the additive to the leading edge 43A and the first portion 43B of the web 16 forming the first set of windings around the mandrel 28 for each coreless log product 30, or to begin to apply the additive near the leading edge 43A of the web 16 at a location beyond the location where a transfer adhesive applied to the winding mandrel 28 makes contact with the web 16 and to continue to apply the additive to the remainder of the first portion 43B of the web 16 forming the first set of windings around the mandrel 28 for each coreless log product 30. In the idle position of the subplate 48, the anilox (supply) roller 44 may be moved to a position to disengage from the applicator roller 42 so as to stop the transfer of additive from the applicator roller to the web over a second distance 43C of the web 16. The period of oscillation may be set to coincide with the timing of web transfer, for instance, when the additive applicator 40 is configured for use with a hole reinforcing agent. In one example implementation, a coreless bathroom tissue product with a total web length of 30 meters may be provided with an additive on the first 1.5 m of the web that forms the first set of windings around the mandrel after web transfer. At a web speed of 600 meters per minute, one log of the example product would be produced every 3 seconds, with the supply roller in the engaged position for 0.15 seconds and in the disengaged position for 2.85 seconds. Various settings may be varied with web speed, depending on the extent to which the amount of additive transferred to the web varies with web speed. The rotational speed of the supply roller 44 may be varied with web speed. The proximity of the supply roller 44 to the applicator roller 42 when in the engaged position may be varied with web speed, for example via direct servo position feedback of the position of the supply roller, or for example via changing a position of one or more mechanical stops to which the supply roller assembly is pivoted. The length of web over which the additive is applied may be different for different products and/or paper grades, and/or the length of web over which the additive is applied may be varied with web speed. The period of oscillation may be set to coincide with other parameters, for instance, when the additive applicator 40 is configured for use with a coating for the log 30. FIGS. 6 and 7 show configurations of the log with the additive applied to the leading edge 43A of the web material and the first portion 43B of the web material and discontinuance of application of the additive in the second portion 43C of the web material. Additive supply lines 54 may lead from an additive source such as a tank (not shown) to the doctor chamber 46 so as to supply the additive to the supply roller 44.

[0021] In another aspect, the applicator roller may be configured to intermittently supply the additive to the web and/or mandrel, as the case may be. In such an arrangement, the applicator roller, the supply roller and the doctor chamber may be mounted on the subplate. In such a configuration, in the application position of the subplate, the applicator roller may engage with the web so to apply the additive to the first portion of the web forming the first set of winding around the mandrel for each coreless log product. In the idle position of the subplate, the applicator roller may be moved to a position to disengage from the web. The supply roller may be positioned relative to the applicator roller so as to apply the additive to the applicator roller on a continuous basis.

[0022] As there is often limited space in the rewinder 10 for the additive applicator 40, the anilox (supply) roller 44 and doctor chamber 46 may need to be relatively small. When space is very limited, two or more additive applicators 40 each comprising the subplate 48 with the anilox (supply) roller 44 and doctor chamber 46 may be spaced in the cross machine direction, for instance, as shown in FIG. 5. One or more applicator rollers 42 may be used. For instance, as shown in FIG. 6, an applicator roller is used with each supply roller. While such a configuration may result in one or more gaps in the additive application, the spacing and properties of the additive may be sufficiently functional as if applied across the entire width of the web 16.

[0023] In another aspect, the applicator roller 42 may be configured to intermittently supply an additive to a last portion of the web that forms the last set of windings 18 around the mandrel after web transfer for tail sealing in a manner similar to that described earlier when the applicator roller applies the additive to the leading edge 43A of the web material. For coreless products with additives applied, the additive would ideally also serve as the tail sealing adhesive. For cored products, the additive may be a tail sealing adhesive.

[0024] In another aspect, a secondary applicator 56 may be used to assist in absorption of the additive into the web material. For instance, as shown in FIG. 9, the secondary applicator 56 may include a brush 58 that is arranged opposite the applicator roller 42 to press lightly on the back side of the web 16 (on the side of the web opposite the applicator roller) to help the web absorb the fluid additive. The secondary applicator 56 may include an actuator 60 arranged to move the brush as needed, for instance, so the brush engages and disengages with the web as desired. The period of oscillation of the actuator 60, and thus the brush 58, may coincide with period of oscillation of the subplate 48 so the brush 58 (or secondary applicator) is applied to the web simultaneously or substantially simultaneously with the additive from the applicator roller 42. In the alternative, the brush (or secondary applicator) may be applied to the web continuously in which case an actuator may not be needed. In the alternative, application of the brush (or secondary applicator) may be based upon web speed, that is, the brush (or secondary applicator) is applied to the web whenever the web speed is above a certain threshold speed. The angle of the brush 58 relative to the web 16, and the amount of interference between the brush 58 and the web 16, may be adjustable to suit the needs of the application.

[0025] Further embodiments can be envisioned by one of ordinary skill in the art after reading this disclosure. In other embodiments, combinations or sub-combinations of the above-disclosed invention can be advantageously made. The example arrangements of components are shown for purposes of illustration and it should be understood that combinations, additions, re-arrangements, and the like are contemplated in alternative embodiments of the present invention. Thus, various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims and that the invention is intended to cover all modifications and equivalents within the scope of the following claims.