PASSIVE EDGE GUIDING METHOD AND APPARATUS

Abstract

Web handling apparatuses and methods are provided to passively control a lateral position of a moving web. The web wraps around support rollers adjacent opposed web edges. One or more guide rollers are positioned adjacent to the support rollers. The guide rollers are in rolling contact with the web edge to guide the moving, misguided web back into its desired lateral position.

Description

BACKGROUND

In general, a functional film can be made on a process line by delivering an uncoated web material, applying a coating composition to the web material, and performing drying or other treatment steps to process the coating composition to form a coating layer on the web material. The coating composition is often not coated across the full width of the web material, and the uncoated margins are eventually cut off prior to winding up the coated web product.

Rollers can be utilized to convey the web material on the process line. Thin web substrate materials can be particularly difficult to transport over or between the rollers on the process line without causing wrinkles, kinks, bagginess, and the like, and such defects can significantly reduce the value of the coated web product. In addition, passing very thin or delicate coatings over and through rollers can damage the coating layer, which also reduces the value of the coated web product to a potential customer. Various techniques for web handling are described in, for example, WO2013/090134 (Swanson et al.) and WO2016/106043 (Jerry et al.).

Reducing frictional force at an interface between the surface of the rollers and the surface of the web material can be helpful in reducing these types of defects. For example, reducing the tension on the web substrate material, changing the material on the surfaces of the rollers that contacts the web substrate (for example, using o-rings or sleeves on the contacting surfaces of the rollers), and reducing the wrap angle at which the web substrate contacts the roller have been employed.

SUMMARY

There is a desire to precisely control the position of a moving web in a cross direction perpendicular to the longitudinal, or “machine direction.” Some embodiments of the apparatus disclosed in WO2016/106043 (Jerry et al.) disclose transporting a web substrate material over an arrangement of at least two support rollers in which the rollers contact the web substrate material only at opposed edges thereof. The web wraps the at least two support rollers with a substantial wrap angle. This wrap angle is part of what allows the positioning of rollers at opposed edges of the web substrate material, leaving a center region of the web substrate material substantially unsupported by the rollers. In effect, the web material is forced into a configuration as a partial cylinder, increasing its resistance to buckling.

The present disclosure found that this buckling resistance can be exploited to provide a mechanism to steer the lateral edge of the web for applications where precise positioning in the cross web direction is required. In some embodiments, one or more guide rollers can be positioned adjacent to the support rollers to passively control a lateral position of a moving web: when the guide rollers are in rolling contact with the respective web edge(s) of the moving web along a cross-web or lateral direction, the web can be guided to move back to its desired lateral position. In some embodiments, the term “passive control” means that the position of a guide roller can be fixed and achieve the objective of moving the misguided web back into the target position by exerting force on the edge of the web. In some embodiments, the position of a guide roller can be pre-adjusted to be at a predetermined position so as to be in rolling contact with the edge of the web.

In one aspect, the present disclosure is directed to a web handling apparatus having first and second support rollers. A web is configured to wrap around the first and second support rollers adjacent first and second web edges, respectively. The first and second support rollers are rotatable to move the web along a length direction thereof. The web handling apparatus further includes first and second guide rollers positioned adjacent the first and second support rollers, respectively. The first and second guide rollers are configured to control a lateral position of the web by contacting the respective first or second edge of the web along a lateral direction thereof substantially perpendicular to the length direction.

In another aspect, the present disclosure is directed to an apparatus for transporting a web material. The apparatus includes a first support roller positioned to contact a major surface of a web adjacent a first edge of the web, and a second support roller positioned to contact the major surface of the web adjacent a second edge thereof opposite the first edge. A first guide roller is positioned adjacent the first support roller. The web wraps around the first and second support rollers adjacent the first and second edges thereof, respectively. The first guide roller is configured to be in rolling contact with the first edge of the substrate when the web shifts laterally toward the first guide roller.

In yet another aspect, the present disclosure is directed to a method including wrapping a web around first and second support rollers adjacent opposite first and second edges of the web, respectively. The first and second support rollers are rotatable to move the web along a length direction thereof. The method further includes providing a first guide roller adjacent the first support roller, and adjusting the lateral position of the web by contacting the first guide roller to the first edge of the web along a lateral direction of the web substantially perpendicular to the length direction.

Various unexpected results and advantages are obtained in exemplary embodiments of the disclosure. One such advantage of exemplary embodiments of the present disclosure is that the lateral position of a web can be precisely controlled without touching the central portion of the web's major surfaces. This is accomplished by positioning one or more guide rollers adjacent to the support rollers. When a moving web shifts laterally from its desired position, the one or more guide rollers can be in rolling contact with the web edge(s) to guide the web back into its desired lateral position.

Various aspects and advantages of exemplary embodiments of the disclosure have been summarized. The above Summary is not intended to describe each illustrated embodiment or every implementation of the present certain exemplary embodiments of the present disclosure. The Drawings and the Detailed Description that follow more particularly exemplify certain preferred embodiments using the principles disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more completely understood in consideration of the following detailed description of various embodiments of the disclosure in connection with the accompanying figures, in which:

FIG. 1 is a schematic perspective view of an embodiment of a web handling apparatus.

FIG. 2 is a schematic side view of a roller in a web handling apparatus.

FIG. 3 is a schematic perspective view of an embodiment of a web handling apparatus.

FIG. 4 is a schematic overhead view of a die coating system including an embodiment of a web handling apparatus.

FIG. 5 is a schematic side view of a spray coating system including an embodiment of a web handling apparatus.

FIG. 6 is a web material processing system including an embodiment of a web handling apparatus.

FIG. 7A is a perspective view of a guide roller, according to one embodiment.

FIG. 7B is a perspective view of a guide roller including a groove, according to another embodiment.

In the drawings, like reference numerals indicate like elements. While the above-identified drawing, which may not be drawn to scale, sets forth various embodiments of the present disclosure, other embodiments are also contemplated, as noted in the Detailed Description. In all cases, this disclosure describes the presently disclosed disclosure by way of representation of exemplary embodiments and not by express limitations. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of this disclosure.

DETAILED DESCRIPTION

There is a desire to precisely control the position of a moving web in a cross direction perpendicular to the longitudinal, or “machine direction.” Some embodiments of the apparatus disclosed in WO2016/106043 (Jerry et al.) include a substantial wrap angle around the at least two rollers which contact a substrate in the form of a web of material of indefinite length. This wrap angle is part of what allows the positioning the rollers at opposed edges of the web substrate material, leaving a center region of the web substrate material substantially unsupported by the rollers. In effect, the web is forced into a configuration as a partial cylinder, increasing its resistance to buckling.

The present disclosure found that this buckling resistance can be exploited to provide a mechanism to steer the lateral edge of the web for applications where precise positioning in the cross web direction is required. One or more guide rollers can be positioned adjacent to the support rollers to passively control a lateral position of a moving web: when the guide rollers are in rolling contact with the respective web edge(s) of the moving web along a cross-web or lateral direction, the web can be guided to move back to its desired lateral position.

Exemplary embodiments of the present disclosure may take on various modifications and alterations without departing from the spirit and scope of the present disclosure. Accordingly, it is to be understood that the embodiments of the present disclosure are not to be limited to the following described exemplary embodiments, but is to be controlled by the limitations set forth in the claims and any equivalents thereof.

Various exemplary embodiments of the disclosure will now be described with particular reference to the Drawings. Exemplary embodiments of the present disclosure may take on various modifications and alterations without departing from the spirit and scope of the disclosure. Accordingly, it is to be understood that the embodiments of the present disclosure are not to be limited to the following described exemplary embodiments, but are to be controlled by the limitations set forth in the claims and any equivalents thereof.

Referring to FIG. 1, an embodiment of a portion of a web handling apparatus 120 is illustrated. A web material 122 with a first edge 122a and second opposed edge 122b moves in a direction D₁. The web material 122 has a length substantially longer than its width, and moves along its length direction. In this view, components of the web handling apparatus 120 that are shown through the transparent web material 122 are depicted with lines of lighter weight for visual clarity.

The web material 122 wraps around a first support roller 130 and a second support roller 132 adjacent the first edge 122a and the second edge 122b, respectively. The support rollers each may have a width substantially smaller than the width of the web material. A shaft 124 is provided to support the first roller 130 and the second roller 132. The web material 122 has its surface portions 14 and 15 adjacent the first and second edges 122a and 122b to move over the surfaces of the support rollers 130, 132, turns, and moves downstream of the support rollers 130, 132 in a direction D₂. In some embodiments, the surfaces of the support rollers 130, 132 can include o-rings or sleeves to modify the coefficient of static friction at an interface with the web material 122. In some embodiments, the support rollers 130, 132 can be idler rollers.

The support rollers 130 and 132 toe outwardly at angles θ₁ and θ₂, respectively, with respect to the direction A to produce an optimum path for the web material 122. While not wishing to be bound by any theory, presently available evidence indicates that the toed outward orientation of at least one of the rollers can gently pull the web material 122 in a web-cross or lateral direction normal to its length direction (e.g., the direction A), which can maintain tension in the web material 122 and help to maintain sufficient engagement between the support rollers 130, 132 and the opposed surface portions 14 and 15 to transport the web material 122.

In the depicted embodiment, the shaft 124 is sufficiently bowed to cause at least one of the support rollers 130, 132 to toe outwardly. It is to be understood that the support rollers 130 and 132 can be supported by different shafts and the outward angles θ₁ and θ₂ can be separately controlled. It should be noted that it is not necessary that θ₁=θ₂, and θ₁ and θ₂ can be independently selected from greater than about 0° to about 6°, or greater than about 0 to about 2°, or greater than about 0° to about 1°, or about 0.2° to about 0.8°.

The shaft 124 may be bowed using any suitable mechanical mechanism such as, for example, a push rod, a four-bar mechanism, a cam mechanism, and the like. In the embodiment of FIG. 1, a push rod 134, which is mounted on a support 136 and adjustable by a suitable mechanism such as a threaded bolt 138, engages the shaft 124 and moves the shaft 124 in the direction A. The “bowing” of the shaft 124 can be modified by adjusting the push rod 134.

The web handling apparatus 120 of FIG. 1 further includes a first guide roller 32 and a second guide roller 34 that are shown in contact with the first edge 122a and the second edge 122b, respectively. The first and second guide rollers 32 and 34 are provided to constrain the cross-web or lateral position of web material 122 by contacting the respective first or second edge 122a or 122b along a lateral direction thereof substantially perpendicular to the length direction A. In some embodiments, the guide rollers 32 and 34 can be supported by their respective shafts (not shown) substantially perpendicular to the shaft 124.

The first and second guide rollers 32 and 34 each are rotatable about their respective axes. See arrows 32a and 34a in FIG. 1. The first and second guide rollers 32 and 34 each have a contacting surface 32s or 34s positioned to be in rolling contact with the respective first or second web edge 122a or 122b. Upon contacting the web edges, the guide rollers 32 and 34 can rotate as indicated by the arrows 32a and 34a. When the lateral position of web material 122 shifts towards one side (e.g., towards the first guide roller 32 or the second guide roller 34), the corresponding guide roller 32 or 34 can be in rolling contact with the respective edges 122a or 122b of the web material 122 to guide the web material 122 to move back to its original lateral position.

The surfaces 32s, 34s of the guide rollers 32, 34 in rolling contact the web material 122 can be independently selected from a wide range of materials including, for example, natural and synthetic rubber, silicone, polymeric materials, metals, and the like. In some embodiments, the surfaces 32s, 34s of the guide rollers 32, 34 can include o-rings or sleeves to modify the coefficient of static friction at an interface with the web material 122. In some embodiments, the surfaces 32s, 34s of the guide rollers 32, 34 can be independently shaped or modified to achieve the desired rolling contact with the web edges. Exemplary guide rollers are shown in FIGS. 7A-B and will be described further below.

Surprisingly the web material 122 even with a thin thickness can endure the contact to the guide rollers 32 or 34 without substantial bending or tearing, which may be, at least partially, attributed to that the first 32 and second 34 guide rollers are positioned adjacent the first 130 and second 132 support rollers, respectively. In some embodiments, the longitudinal distance d1 or d2 of the span of the web material 122 between the guide roller 32/34 and the support roller 130/132 may be in a range, for example, from about 1 cm to about 10 cm. It is to be understood that the longitudinal distance d1 or d2 may depend on other process parameters such as, for example, the width of the web material, the thickness of the web material, the stiffness of the web material, the stress applied to the web material by the support rollers, the length of the span of the web material between adjacent support rollers along the length direction, etc. In general, the guide rollers 32 or 34 can be positioned at any suitable distance adjacent to the corresponding support roller as long as such rolling contact with the web edge would not introduce any substantial bending or tearing in the web material 122.

In the depicted embodiment, the first 32 and second 34 guide rollers are upstream of first 130 and second 132 support rollers, meaning that the advancing web material 122 may encounter the first 32 and second 34 guide rollers before it encounters the first 130 and second 132 support rollers. This is believed to be a more convenient positioning, but placement of guide rollers downstream of the support rollers 130 and 134 is considered to be within the scope of this disclosure.

In some embodiments, one or a pair of first guide rollers can be positioned upstream of the support rollers; one or a pair of second guide rollers can be positioned downstream of the support rollers. This configuration can facilitate running web both forwards and backwards. It might be desirable to place guide rollers at the web entrance and web exit of each idler roller so that a guide roller can be always positioned at the end of the web span entering the idler roller, no matter which direction the web may be travelling.

In some embodiments, the first and second guide rollers 32 and 34 are positioned such that a distance between the contacting surfaces 32s, 34s is substantially the same as the width of the web material 122. In some embodiments, the distance between the contacting surfaces 32s, 34s may be slightly greater than the width of the web material 122 with a predetermined tolerance T, which may be in the range, for example, from about 0.1 mm to about 10 cm. Any possible lateral shift of the moving web material 122 can be constrained to be smaller than the tolerance T.

It is not necessary that embodiments of apparatus 120 within the scope of the present disclosure have both guide rollers 32 and 34. In some embodiments, only one of the guide rollers 32, 34 is provided to be positioned adjacent to the corresponding support roller 130 or 132. At least one of the support rollers 130, 132 can be adjusted such that a tension can be maintained in the web material 122 to prevent it from shifting laterally toward one direction. For example, in some embodiments, angles θ₁ and θ₂ may be chosen to impart a slight bias towards a single guide roller (32, say) which can alone locate the position of the corresponding edge (122a).

In the depicted embodiment of FIG. 1, the pair of support rollers 130 and 132 are provided to pull the web material 122 in the lateral direction and maintain tension in the web material 122 when it turns around the support rollers 130 and 132. At least one of the guide rollers 32 and 34 is positioned to be in rolling contact with the edges of the moving web material 122 when the web material 122 shifts laterally from its desired position. Regarding the longitudinal position of the guide roller(s), it can be positioned adjacent to the corresponding support roller where a sufficient web tension is maintained to prevent any substantial bending or tearing in the web material caused by the rolling contact. It is to be understood that any mechanisms that can supplement or replace the support roller(s) to provide suitable web tension can be used.

Referring to FIG. 2, a schematic side view of the embodiment of FIG. 1 is illustrated so as to clarify what is meant by wrap angle. The web material 122 moving in the direction D1, contacts the first roller 130 of FIG. 1 at a first point A, wraps at an angle β around the circumference of the first roller 130, and then separates from the first roller 130 at a point B to turn and move in the direction D2. In various embodiments, wrap angles of about 90° to about 230° have been found to be suitable, depending on the nature of the web material 122 and process conditions.

In another embodiment shown in FIG. 3, a portion of a web handling apparatus 200 includes a roller 230 mounted on a shaft 224. The shaft 224 is mounted to or part of a roller support 250. The shaft 224 is angularly adjustable through a pivot point 252 between the roller support 250 and a structural mounting element 254. As shown schematically in FIG. 3, the shaft 224 can move through a wide range of angles α in a plane including a longitudinal axis of the shaft 224 along a direction y and a direction of travel x of a web material 222. In other embodiments not shown in FIG. 3, the shaft 224 could also be made angularly adjustable through a range of angles above or below the plane including the longitudinal axis y of the shaft 224 and the direction of travel x of the web material 222. As the shaft 224 is adjusted through the angles α, the angle of contact between the roller 230 mounted thereon and the web material 222 also changes, and the shaft 224 can be adjusted to produce a desired contact angle between the roller 230 and the web material 222. As shown in FIG. 3, the shaft 224 can be adjusted such that an edge 222a of the web material approaching the first contacting roller 230 and moving in direction D₁ upstream of the roller 230 turns about the roller 230 and moves in a direction D₂ downstream of the roller 230 without wrinkling, creasing or bunching.

Various configurations of support roller are described in WO2016/106043 (Jerry et al.), “Edge Contact Substrate Transport Method and Apparatus,” where the support rollers contact the web substrate material only at opposed edges thereof. Positioning the rollers at opposed edges of the web substrate material leaves a center region of the web substrate material between the opposed edges that is un-contacted by the rollers and remains substantially unsupported by the rollers. WO2016/106043 (Jerry et al.) is hereby incorporated by reference as if rewritten.

The web handling apparatus 200 of FIG. 3 further includes a guide roller 36 that is shown in contact with the web edge 222a. The guide roller 36 is provided to constrain the cross-web or lateral position of web material 222. In some embodiments, the guide roller 222a can be supported by a shaft substantially perpendicular to the mounting element 254.

The guide roller is rotatable about its axis. See arrow 36a in FIG. 3. The guide roller 36 has a contacting surface 36s to contact the web edge 222a. Upon contacting the web edge, the guide roller 36 can rotate as indicated by the arrow 36a. When the lateral position of web material 222 shifts towards the first guide roller 36, the guide roller 36 can contact the web edges 222a, rotate, and guide the web material 222 to move back to its original lateral position.

The web handling apparatuses described above can be used in a wide variety of web material processing operations. For example, a portion of a roll-to-roll web material processing system 750 depicted in FIG. 4 includes a web material handling apparatus 700 and a coating die 752. In the web handling apparatus 700, a web material 722 moves in a direction A and traverses an arrangement of support rollers 712, 714. The support rollers 712, 714 rotate about a shaft 720. At least one of the support rollers 712, 714 is toed outward and positioned at an angle θ in a plane x-y with respect to a direction x normal to a longitudinal axis y of the shaft 720. In the embodiment of FIG. 4, the support roller 712 is angled at an angle θ₁ and the support roller 714 is angled at an angle θ₂ with respect to the direction x. In various embodiments, it is not necessary that θ₁=θ₂, and θ₁ and θ₂ can be independently selected from greater than about 0° to about 6°, or greater than about 0 to about 2°, or greater than about 0° to about 1°, or about 0.2° to about 0.8°. As the web material 722 traverses the support rollers 712, 714, the coating die 752 deposits a coating composition 753 on a surface 725 of the web material 722 to form a coating layer 755 thereon.

The web handling apparatus 700 further include guide rollers 732 and 734 to provide web lateral position control in the cross web direction y. The guide rollers 732 and 734 may have similar structures as the guide rollers 32 and 34 of FIG. 1, and configured to control a lateral position of the web material 722 by contacting the edges of the web along the cross-web or lateral direction thereof, while rotating about their respective axes.

In another example shown in FIG. 5, a roll-to-roll web material processing system 850 includes a web material handling apparatus 800 and a spray coater 852. The web handling system 800 includes a set of support rollers 802. A web material 822 wraps around the set of support rollers 802 at the opposite web edges thereof. The set of support rollers 802 may have a similar configuration as the support rollers of FIG. 1 or 3. A guide roller 832 is positioned adjacent to one of the support rollers 802, and configured to control a lateral position of the web material 822 by contacting the adjacent web edge along the cross-web direction (e.g., into the paper).

As the web material 822 traverses guide roller 832 and roller 802, the spray coater 852 deposits a coating composition 853 on a surface 825 of the web material 822 to form a coating layer 855 thereon. The processing system 850 shown schematically in FIG. 5 is particularly well suited to deposition of very thin coating layers 855 or deposition of coating compositions on very delicate web materials 822, or both. While not wishing to be bound by any theory, presently available evidence suggests that reducing the number and width of rollers underlying the web material 822 can reduce or substantially prevent damage to sensitive coatings or wrinkling and creases in very thin web materials.

In another example shown in FIG. 6, a roll-to-roll web material processing system 950 includes a web material handling apparatus 900 in a multi-chamber deposition apparatus 960. The web material handling apparatus 900 includes a first set of drive rollers 902 and a second set of drive rollers 904. At least one roller in the first set of drive rollers 902 and the second set of drive rollers 904 is bowed outward at an angle selected from greater than about 0° to about 6°, or greater than about 0 to about 2°, or greater than about 0° to about 1°, or about 0.2° to about 0.8°. The web handling system 900 further includes a first set of idler rollers 980 and a second set of idler rollers 982, each arranged to turn a web material 922. The web material 922 wraps around the rollers 902, rolls 980 and 982 at opposite travelling web spans, and rollers 904. The sets of rollers 980 and 982 can be respectively angled outwardly in a manner similar as shown in FIG. 1.

The deposition chamber apparatus 960 includes a first deposition chamber 961, a third deposition chamber 963, and a second deposition chamber 962 between the first deposition chamber 961 and the third deposition chamber 963. The deposition chambers 961, 962, 963 are substantially isolated from one another. The second deposition chamber houses the first set of drive rollers 902 and the second set of drive rollers 904. The first deposition chamber 961 houses the first arrangement of idler rollers 980 and the third deposition chamber 963 houses the second arrangement of idler rollers 982.

In some embodiments, a first coating composition enters the first deposition chamber 961 at the first deposition chamber inlet 991A and exits the first deposition chamber outlet 991B. As the web material 922 enters the first deposition chamber 961, the first coating composition contacts a surface 925 of the web material 922 to form a coating layer thereon (not shown in FIG. 6). Following deposition of the first coating composition on the surface 925, the web material 922 then enters the second deposition chamber 962, which in some embodiments contains an inert gas input via a second deposition chamber inlet 992A. A second coating composition enters the third deposition chamber 963 at the third deposition chamber inlet 993A and exits the third deposition chamber outlet 993B. The web material enters the third deposition chamber 963 and the second coating composition is applied on the first coating layer forms a coating layer overlying the first coating layer. The web material then traverses the second deposition chamber 962 and the first deposition chamber 961 a predetermined number of additional times forming additional layers of the first coating composition and the second coating composition before the completed coated article is wound up on the second set of rollers 904 in the second deposition chamber.

In another embodiment, the first coating composition and the second coating composition may react to form a coating layer on the surface 925.

The web material handling apparatus 900 further includes one or more guide rollers configured to passively guide the cross-web or lateral position of the moving web material 922. In the depicted embodiment of FIG. 6, one or a pair of first guide rollers 932a are positioned adjacent to the idler roller 980a, configured to be in rolling contact with the edge(s) of the moving web material 922; one or a pair of second guide rollers 932b are positioned adjacent to the idler roller 982a, configured to be in rolling contact with the edge(s) of the moving web material 922. Positioning in the cross-web direction can be accomplished via the one or more guide rollers (e.g., 932a and 932b in the illustrated embodiment).

In some embodiments, it might be most effective to position one or a pair of support rollers at the end of the web span approaching the respective idler rollers 980 or 982, in a similar manner as shown in FIG. 1. For example, for the web travelling in the direction indicated by the arrows on 902, 904, the guide roller(s) 932a are positioned as the web approaches the idler roller 980a. A similarly positioned guide roller would be placed on each of the idler rollers 980, 982.

In some embodiments, it might be desirable to place guide rollers at both the web entrance and web exit of each idler roller so that a guide roller can be always positioned at the end of the web span entering the idler roller, no matter which direction the web may be travelling. For example, when the web travels backwards in a direction opposite to the direction as indicated by the arrows on 902, 904, the guide roller(s) 932b are positioned as the web approaches the idler roller 982a. A similarly positioned guide roller would be placed on each of the idler rollers 980, 982.

In another embodiment, the web handling apparatuses described above may be useful in inspection systems. Since the rollers described herein used have a width that is narrow relative to the width of the web material, the web material is less likely to be distorted by contacting a wide roller or system of rollers, and debris on the rollers is less likely to contaminate the sample being inspected.

Referring now to FIGS. 7A-B, exemplary guide rollers described herein are shown, according to some embodiments. FIG. 7A illustrates a guide roller 30 that is rotatable about its axis and has a periphery surface 30s. A bearing 35 is provided to support the guide roller 30 in rolling contact with a web edge. When the guide roller 30 is in rolling contact with a web edge (e.g., 122a or 122b in FIG. 1), the periphery surface 30s contacts the web edge along a cross-web or lateral direction to control a lateral position of the web. In some embodiments, the periphery surface 30s can be shaped or modified to optimize the rolling contact to the web edge.

In the embodiment of FIG. 7B, a groove 33 is formed into the periphery surface 30s of a guide roller 30′ to receive and further support the edge of the web against folding or buckling. The groove 33 has first and second opposite sides, 33a and 33b, and a bottom surface (not visible in FIG. 7B). The guide roller 30′ is rotatable about its axis. The bearing 35 to support the guide roller 30′ in rolling contact with a web edge can also be seen. When the guide roller 30′ is in rolling contact with a web edge, the web edge (e.g., 122a or 122b in FIG. 1) can contact the bottom surface of the groove 33. The sides 33a or 33b of the groove 33 may contact the surface portions of the web received by the groove 33 to prevent possible folding or buckling. The size of the groove 33 may depend on the desired application. In some embodiments, the groove 33 may have a depth, for example, from about 1 mm to 100 mm, from about 3 mm to 50 mm, or from about 5 mm to 30 mm; the groove 33 may have a width, for example, from about 5 mm to 100 mm, from about 10 mm to 50 mm, or from about 15 mm to 30 mm.

The web handling apparatuses described herein may be used to process web materials at a wide variety of web speeds from about 5 feet per minute (about 13 cm/sec) to about 3000 feet per minute (about 76 m/sec), and may be used in any surrounding medium including air, inert gases, water, vacuum and the like.

In some embodiments, a control system may optionally be used to control and/or maintain the toe out angle of the rollers.

The operation of the present disclosure will be further described with regard to the following detailed example(s). These example(s) are offered to further illustrate the various specific and preferred embodiments and techniques. It should be understood, however, that many variations and modifications may be made while remaining within the scope of the present disclosure.

Example

These Examples are merely for illustrative purposes and are not meant to be overly limiting on the scope of the appended claims. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the present disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

A web handling apparatus was constructed generally as depicted in FIG. 1 with support rollers spaced apart at a distance of 14 inches (35.56 cm) and used to transport web material in the form of a web of indefinite length. Several runs were made with polyethylene terephthalate (PET) of different thicknesses, specifically 0.13 mm, 0.076 mm, and 0.051 mm. The rollers were toed out at an angle of about greater than about 0° to about 6°, or greater than about 0 to about 2°, or greater than about 0° to about 1°, or about 0.2° to about 0.8° as shown in FIG. 1. A web tension of 10 pound-force was applied across the span of the web (1.25 N/linear cm). Guide rollers having a diameter of 1.75 inches (4.45 cm) and possessing a groove having a width of 0.605 inch (1.54 cm) and a depth of 0.25 inch (0.64 cm) were positioned 2.5 inches (6.4 cm) upstream of the support rollers, such that the web was retained within the groove. The web was advanced at a speed of 100 feet/min (30.5 m/min). In spite of the thinness of the web and the length of the unsupported span between the support rollers, the web was conveyed smoothly and without buckling. Further, the contact with the guide rollers was maintained without folding or buckling, such that the cross web position of the web was constrained to a high degree of certainty.

Listing of Exemplary Embodiments

Various embodiments of the present disclosure have been described. These and other embodiments are within the scope of the following claims.

Embodiment A is directed to a web handling apparatus comprising:

first and second support rollers, a web being configured to wrap around the first and second support rollers at first and second web edges, respectively, the first and second support rollers being rotatable to move the web along a length direction thereof; and

first and second guide rollers positioned adjacent the first and second support rollers, respectively, the first and second guide rollers being configured to control a lateral position of the web by contacting the respective first or second edge of the web along a lateral direction thereof substantially perpendicular to the length direction.

Embodiment B is directed to the web handling apparatus according to Embodiment A, wherein the web wraps around the first and second support rollers with a wrap angle of about 90° to about 230°.

Embodiment C is directed to the web handling apparatus according to Embodiments A or B, wherein a span of the web between the first guide roller and the first support roller has a length of about 1 cm to about 10 cm.

Embodiment D is directed to the web handling apparatus according to any of the preceding Embodiments A-C, wherein at least one of the first and second guide rollers includes a groove to receive the first or second edge of the web, the groove having opposite sides configured to contact opposite major surfaces of the web at the first edge.

Embodiment E is directed to the web handling apparatus according to any of the preceding Embodiments A-D, wherein the first and second guide rollers are positioned with a distance therebetween substantially the same as the width of the web.

Embodiment F is directed to the web handling apparatus according to any of the preceding Embodiments A-E, wherein the web comprises an un-contacted region between the first and the second support rolls comprising at least about 50% of the width of the web.

Embodiment G is directed to the web handling apparatus according to any of the preceding Embodiments A-F, wherein at least one of the first support roller and the second support roller is supported on the bowed shaft such that at least one of the first and second support rollers is angled outwardly with respect to a direction of web travel.

Embodiment H is directed to the web handling apparatus according to any of the preceding Embodiments A-G, wherein the first and second support rollers are respectively angled outwardly with an angle θ.

Embodiment I is directed to the web handling apparatus according to Embodiment H, wherein the angle θ is adjustable in a range of about 0° to about 6°.

Embodiment J is directed to the web handling apparatus according to any of the preceding Embodiments A-I, wherein the first and second guide rollers each are positioned at an upstream position of the respective first and second support rollers.

Embodiment K is directed to an apparatus for transporting a web material, the apparatus comprising:

a first support roller positioned to contact a major surface of a web adjacent a first edge of the web;

a second support roller positioned to contact the major surface of the web adjacent a second edge thereof opposite the first edge; and

a first guide roller positioned adjacent the first support roller,

wherein the web wraps around the first and second support rollers adjacent the first and second edges thereof, respectively, and wherein the first guide roller is configured to be in rolling contact with the first edge of the substrate when the web shifts laterally toward the first guide roller.

Embodiment L is directed to an apparatus for transporting a web material according to embodiment K, further comprising a second guide roller positioned adjacent the second support roller, and configured to contact the second edge of the substrate.

Embodiment M is directed to an apparatus for transporting a web material according to embodiments K or L, wherein the first guide roller is positioned at an upstream position of the first support roller.

Embodiment N is directed to a method comprising: wrapping a web around first and second support rollers adjacent opposite first and second edges of the web, respectively, the first and second support rollers being rotatable to move the web along a length direction thereof;

providing a first guide roller adjacent the first support roller; and

adjusting the lateral position of the web by contacting the first guide roller to the first edge of the web along a lateral direction of the web substantially perpendicular to the length direction.

Embodiment O is directed to the method according to Embodiment N, further comprising providing a groove to the first guide roller to receive the first edge of the web, the groove has opposite sides configured to contact opposite major surfaces of the web at the first edge.

Embodiment P is directed to the method according to Embodiments N or O, wherein a central region of the web between the first support roller and the second support roller comprising at least about 80% of a width of the web is free of support from a roller.

Embodiment Q is directed to the method according to Embodiments N-P, wherein the web wraps about the first roller and the second roller at an angle of about 90° to about 230°.

Embodiment R is directed to the method according to Embodiments N-Q, further comprising orienting at least one of the first and second support rollers at an angle θ in a plane x-y with respect to the length direction x normal to the width direction y of the web, and wherein the angle θ is adjustable in a range of about 0° to about 6°.

Embodiment S is directed to the method according to Embodiments N-R, further comprising positioning a second guide roller adjacent the second support roller to contact the second edge of the web.

Embodiment T is directed to the method according to Embodiments N-S, further comprising applying a coating composition on the web, and processing the coating composition to form a coating layer on the web.

Reference throughout this specification to “one embodiment,” “certain embodiments,” “one or more embodiments” or “an embodiment,” whether or not including the term “exemplary” preceding the term “embodiment,” means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the certain exemplary embodiments of the present disclosure. Thus, the appearances of the phrases such as “in one or more embodiments,” “in certain embodiments,” “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily referring to the same embodiment of the certain exemplary embodiments of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

While the specification has described in detail certain exemplary embodiments, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily conceive of alterations to, variations of, and equivalents to these embodiments. Accordingly, it should be understood that this disclosure is not to be unduly limited to the illustrative embodiments set forth hereinabove. In particular, as used herein, the recitation of numerical ranges by endpoints is intended to include all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). In addition, all numbers used herein are assumed to be modified by the term “about.”

Furthermore, all publications and patents referenced herein are incorporated by reference in their entirety to the same extent as if each individual publication or patent was specifically and individually indicated to be incorporated by reference. Various exemplary embodiments have been described. These and other embodiments are within the scope of the following claims.

Claims

1. A web handling apparatus comprising: first and second support rollers, a web being configured to wrap around the first and second support rollers adjacent first and second web edges thereof, respectively, the first and second support rollers being rotatable to move the web along a length direction thereof; andfirst and second guide rollers positioned adjacent the first and second support rollers, respectively, the first and second guide rollers being configured to control a lateral position of the web by contacting the respective first or second web edge along a lateral direction thereof substantially perpendicular to the length direction.

2. The web handling apparatus of claim 1, wherein the web wraps around the first and second support rollers with a wrap angle of about 90° to about 230°.

3. The web handling apparatus of claim 1, wherein a span of the web between the first guide roller and the first support roller has a length of about 1 cm to about 10 cm.

4. The web handling apparatus of claim 1, wherein at least one of the first and second guide rollers includes a groove to receive the first or second edge of the web, the groove has opposite sides configured to contact opposite major surfaces of the web at the first edge.

5. The web handling apparatus of claim 1, wherein the first and second guide rollers are positioned with a distance therebetween substantially the same as the width of the web.

6. The web handling apparatus of claim 1, wherein the web comprises an un-contacted region between the first and the second support rolls comprising at least about 50% of the width of the web.

7. The web handling apparatus of claim 1 further comprises a bowed shaft, wherein at least one of the first support roller and the second support roller is supported on the bowed shaft such that at least one of the first and second support rollers is angled outwardly with respect to a direction of web travel.

8. The web handling apparatus of claim 1, wherein the first and second support rollers are respectively angled outwardly with an angle θ.

9. The web handling apparatus of claim 8, wherein the angle θ is adjustable in a range of about 0° to about 6°.

10. The web handling apparatus of claim 1, wherein the first and second guide rollers each are positioned at an upstream position of the respective first and second support rollers.

11. An apparatus for transporting a web material, the apparatus comprising: a first support roller positioned to contact a major surface of a web adjacent a first edge of the web;a second support roller positioned to contact the major surface of the web adjacent a second edge thereof opposite the first edge; anda first guide roller positioned adjacent the first support roller,wherein the web wraps around the first and second support rollers adjacent the first and second edges thereof, respectively, andwherein the first guide roller is configured to be in rolling contact with the first edge of the web when the web shifts laterally toward the first guide roller.

12. The apparatus of claim 11 further comprising a second guide roller positioned adjacent the second support roller, and the second guide roller being configured to contact the second edge of the web.

13. The apparatus of claim 11, wherein the first guide roller is positioned at an upstream position of the first support roller.

14. A method comprising: wrapping a web around first and second support rollers adjacent opposite first and second edges of the web, respectively, the first and second support rollers being rotatable to move the web along a length direction thereof;providing a first guide roller adjacent the first support roller; andadjusting the lateral position of the web by contacting the first guide roller to the first edge of the web along a lateral direction of the web substantially perpendicular to the length direction.

15. The method of claim 14 further comprising providing a groove to the first guide roller to receive the first edge of the web, the groove has opposite sides configured to contact opposite major surfaces of the web at the first edge.

16. The method of claim 14, wherein a central region of the web between the first support roller and the second support roller comprising at least about 80% of a width of the web is free of support from a roller.

17. The method of claim 14, wherein the web wraps about the first roller and the second roller at an angle of about 90° to about 230°.

18. The method of claim 14 further comprising orienting at least one of the first and second support rollers at an angle θ in a plane x-y with respect to the length direction x normal to the width direction y of the web, and wherein the angle θ is adjustable in a range of about 0° to about 6°.

19. The method of claim 14 further comprising positioning a second guide roller adjacent the second support roller to contact the second edge of the web.

20. The method of claim 14 further comprising applying a coating composition on the web, and processing the coating composition to form a coating layer on the web.