INTRODUCTION

This disclosure relates to rewinding machines that wind a web material to form logs of wound web material, particularly rewinding machines that wind web material into solid logs by winding the web material around itself, without a central cardboard core, tube, mandrel, or shaft. Specifically, the disclosure is directed to an improved apparatus and method for severing the web, initiating winding of the web, and for controlling the logs during the introduction and winding phases. In particular, at least one belt is used in conjunction with a winding drum, which feeds the web, to form a winding nest. The web material may be fed between the drum and the belt. The speed of the belt relative to the web and winding drum, and position of the belt relative to the web and winding drum, may be controlled to cause severing of the web, which produces a leading edge in the web, and initiation of winding of the web into a log by rolling the leading end of the web up on itself and around itself, to form a rotating nucleus which is the beginning of the next log. The belt may be brought in close proximity to the winding drum and cooperate with the winding drum to sever the web material and initiate winding of the web material. The position and surface speed of the belt, relative to the winding drum, are also used to control the logs during the introduction, winding, and discharge phases.

BACKGROUND AND SUMMARY

A rewinder is used to convert large parent rolls of web into smaller sized rolls of bathroom tissue, kitchen towel, hardwound towel, industrial products, nonwovens products, and the like. A rewinder line consists of one or more unwind stations, modules for finishing—such as embossing, printing, perforating—and a rewind station at the end for winding. Typically the rewind station produces logs having a diameter of between 90 mm and 180 mm for bath tissue and kitchen towel and between 150 mm to 350 mm diameter for hardwound towel and industrial products. The width of the logs is usually 1.5 m to 5.4 m, depending on the parent roll width. Typically the logs are subsequently cut transversely to obtain small rolls having a width of between 90 mm and 115 mm for bath tissue and between 200 mm to 300 mm for kitchen towel and hardwound towel. In some cases the web from the parent roll is slit into ribbons and wound with the finished roll width at the rewind station, without the need for subsequent transverse cutting.

Typically the finished rolls have a through hole, or passage, at the central part of the roll, parallel to the axis of the roll. This passage may be formed by a tubular core, or the roll may be coreless. The central passage is useful for mounting the finished roll on a shaft or spindle for dispensing. However, some finished rolls have no through hole, or central passage, and instead are wound solid. The solid rolls do not have a separate core, but the center “core” is in essence a solid nucleus of web material windings. Depending on the methods and the conditions at the start of the winding, the nucleus may be higher or lower density than the windings of web around it. Nonetheless, the roll may be regarded as solid. A benefit of solid rolls is that more web material may be fit into the same diameter roll, due to the lack of a central passage, or void.

Two types of rewinding systems are commonly used for producing wound logs: center winders and surface winders. The defining characteristic of center winders is that the web is wound on a core that is supported and rotationally driven by a mandrel within the core, or in the alternative, the web may be wound directly on the mandrel, as in the case of coreless products. Because center winders require through holes in the finished logs for the winding mandrels, solid logs and rolls are produced on surface winders. The defining characteristic of surface winders is that the web is wound into a log that is supported and rotationally driven by machine elements at the log periphery. Thus, surface winding does not require through holes in the finished logs, and may be adapted to produce solid logs.

In co-owned and co-pending PCT application serial no. PCT/US2018/062462, and U.S. application Ser. No. 16/201,034, the disclosures of which are incorporated by reference herein, a surface rewinder is disclosed for winding the web material around central cores to form logs of wound web material, and for controlling the logs during the introduction, winding, and discharge phases. At least one belt is used in conjunction with a winding drum, which feeds the web, to form a winding nest. Between the drum and belt is a space through which the winding cores are inserted and through which the web material is fed. The belt is a continuous flexible member arranged as an endless loop, operably mounted so it can be moved with a velocity tangent to its surface. The belt is made to move with surface velocity in a direction generally opposite that of the inserted core and feeding web. This surface velocity of the belt, acting with the generally opposite surface velocity of the winding drum, causes the log to turn in rotation to wind the web material. In the co-owned and co-pending applications, it is disclosed that a stationary rolling surface is provided upstream from the belt, on the same side of the space between the winding drum and the belt as the belt. The inserted core is driven in rotation by the winding drum along the stationary rolling surface and then into a space between the winding drum and the belt.

In the present disclosure, it is an object to provide a rewinding system capable of being easily changed over between winding web material on cores or mandrels and winding web material into solid logs without a core or mandrel. It is also an object to provide a rewinding system that is capable of winding solid logs.

Thus, in one aspect, the rewinding system as disclosed in the co-owned and co-pending applications may be modified and adjusted to allow the surface of the belt to be brought into close proximity to the winding drum and cooperate with the winding drum to sever the web material and initiate winding of the web material around a lead edge (e.g., the just severed edge) of the web material to form a solid roll. The position and surface speed of the belt relative to the winding drum may be further used to control the progression of the winding log during its introduction into the winding nest, and thereafter, the subsequent winding and discharge phases of the wind cycle. It is advantageous that a single device, the belt, may be used for severing the web at the start of a product cycle, initiating winding of the web into a rotating log, controlling its introduction into the winding nest, completing the winding of the log, and controlling its discharge.

As will be described in more detail below, at least one belt is used in conjunction with a winding drum to form a winding nest. The web material is fed between the drum and belt. The belt is a continuous flexible member arranged as an endless loop, operatively mounted relative to the winding nest, so the belt can be moved with a velocity tangent to its surface. The belt may be adjusted to be near the winding drum so as to cooperate with the winding drum to sever the web material and initiate winding of a successive roll about the lead edge of the web material, for instance, the edge just severed. For instance, as the time for the severing of the web material approaches, the belt may be moved from its log winding position to a position close to the winding drum. The surface speed of the belt may be reduced, causing the winding log to separate from contact with the winding drum thereby initiating discharge of the winding log. Then, the surface of the belt may be moved toward the winding drum, and depending upon the application, against the winding drum, into contact with the web material between the winding drum and the belt. The belt may be made to move with surface velocity in a direction generally opposite that of the feeding web. The surface velocity of the belt acting with the generally opposite surface velocity of the winding drum serves to sever the web. It is preferable that the web have at least one line of perforations, where it is intended to be severed, and that the moment and duration of contact of the belt with the web material against the winding drum be synchronized with the line or lines of perforations in the web material so that a line of perforations immediately downstream of the point of contact of the belt with the web material is cleanly severed.

The pressure of the belt and its opposite direction of travel may induce the leading end of the web material to roll over itself, and around itself, and thereby form a rotating nucleus of the web material about which the remainder of the roll is wound. The position and surface speed of the belt are controlled to cause the forming log to roll forward as it rotates, so it advances through the space between the winding drum and the belt and progresses into the winding nest as it rotates and increases in diameter. As mentioned above, the belt is made to move with surface velocity in a direction generally opposite that of the feeding web. The surface velocity of the belt, acting with the generally opposite surface velocity of the winding drum, causes the log to turn in rotation to wind the web material about itself.

In another aspect of the disclosure, the surface velocity of the belt is varied cyclically relative to the velocity of the winding drum to control the advancement of a log through the space between the winding drum and the belt into the winding nest.

In another aspect of the disclosure, the surface velocity of the belt is varied cyclically relative to the velocity of the winding drum to control the winding of a log in the winding nest.

In another aspect of the disclosure, the surface velocity of the belt is varied cyclically relative to the velocity of the winding drum to control the discharge of a log from the winding nest.

In another aspect of the disclosure, the surface velocity of the belt is varied cyclically relative to the velocity of the winding drum and the distance between the belt and the winding drum is varied cyclically to control the advancement of a log through the space between the winding drum and the belt into the winding nest.

In another aspect of the disclosure, the surface velocity of the belt is varied cyclically relative to the velocity of the winding drum and the distance between the belt and the winding drum is varied cyclically to control the winding of a log in the winding nest.

In another aspect of the disclosure, the surface velocity of the belt is varied cyclically relative to the velocity of the winding drum and the distance between the belt and the winding drum is varied cyclically to control the discharge of a log from the winding nest.

In another aspect of the disclosure, the winding nest is provided with a rider roll, which is rotatably mounted, and is movable relative to the winding drum and the belt to allow an increase in diameter of each log in the winding nest.

In another aspect of the disclosure, the belt is substantially under the winding log in the winding nest.

In another aspect of the disclosure, the winding log remains substantially in contact with the winding drum during a preponderance of the winding cycle, until it is nearly complete, when it separates from the winding drum at the start of log discharge from the winding nest.

In another aspect of the disclosure, the winding log remains substantially in contact with the belt during a preponderance of the winding cycle, from when it first contacts the belt, until it moves away from the belt during log discharge from the winding nest.

In another aspect of the disclosure, the winding log remains substantially in contact with a rider roll during a preponderance of the winding, from when it first contacts the rider roll, until it is nearly complete, when it separates from the rider roll during log discharge from the winding nest.

