Referring initially to
The composite web 11 is formed (or reoriented after forming) with the fluted web component 15 facing upwardly. As the composite web 11 exits the single facer 16, it is slit longitudinally on its centerline by a slitting blade 20 to form two web halves 21 and 22. A suitable glue or adhesive is applied to the flute tips of the lower web half 21 by a glue roll 23. The other web half 21 is directed onto an angled turning bar 24 around which it is wrapped and displaced laterally to bring it into contact with the glued web half 21 where the smooth web face of the web half 22 is laid onto the glued flute tips of the other web half 21 to form an open face double wall web 25. The double wall web 25 is directed over a heating plate 26 or other heating device to cure the adhesive and permanently join the two web halves 21 and 22. As will be described in greater detail below with respect to the presently preferred embodiment, the flutes of the two component webs forming the open face double wall web 25 are brought together and joined so that the flutes of the two component webs are in flute tip-to-flue tip alignment.
The open face double wall web 25 is then slit longitudinally with a multi-blade slitter 27 to form a plurality of equal width open face double wall strips 28. The open face double wall web 25 has an upper exposed fluted face and, therefore, the strips 28 also have laterally extending flutes. The strips then pass beneath a second glue roll 30 which applies a suitable adhesive to the exposed flute tips. When the plurality of strips 28 reaches a selected length in the machine direction, a cut-off knife 31 downstream of the glue roll cuts the strips 28 to a common length. The strips are preferably cut at the bottom of the next flute which will provide a core element just slightly larger than the desired length. The plurality of glued and cut strips 32 is accelerated on a transport conveyor 33 to form a gap between the strips and the next-following uncut strips.
The plurality of glued and cut strips 32 is then cross-transferred out of the machine direction path of the next following plurality of strips and onto a lateral feed conveyor 34 to a strip upender 35. As is best seen in
In this embodiment, as the core element 13 is being formed, a set of conveyor belts 41, positioned over the top of the core element, applies a normal force to assist in compacting the core element and press the glued flute tips of each strip to the smooth face of the preceding strip by running slightly faster than the advancing core block which is held back by downstream holding rolls.
When a core element 13 comprising a desired number of strips has been formed, the core element 13 is accelerated into a trim and cut station where it can be cut into any number of smaller core elements. In the example shown in
The height or thickness of the core element 13 depends on the width to which the strips 28 are slit. The length of the core element 13 can be varied as desired. Thus, the system has the capability of continuously and rapidly forming core elements of widely varying dimensions.
Composite fluted webs, useful in forming core elements, can be made in a number of different ways, can utilize different kinds of web materials, and the fluted web can be formed in various ways. As indicated above, it is preferable to utilize a flute size for the fluted web that is larger than flutes commonly made on a typical single facer. A larger flute size will provide adequate strength for the core element, but utilize significantly less paper or other web material in the formation of the fluted web.
Referring to
As the webs 44 and 46 come into the fluting nip 45, they are simultaneously fluted, one flute at a time, and joined by the adhesive previously applied to the contacting face of one of the webs. The joined webs are held together in a straight fluting run 54 of the fluting conveyors 50 and 51 to which heat is applied by upper and lower heating elements 50 and 51 to bond and cure the adhesive. Each of the fluting conveyors 50 and 51 may include flute pre-heaters 57 to help maintain the temperature of the fluting bars 52. A composite fluted web 58 exits the fluting conveyors 50 and 51 at their head ends where, preferably, the conveyor flights are separated gradually on a much larger radius arc than that of the tail sprockets 47 and 48. The resulting composite fluted web 58 is substantially cured and rigid enough for further processing with or without the addition of a smooth facing web.
A composite fluted web 58 of the foregoing type could, for example, be glued to a smooth web and the web processed to form core elements in the manner previously described. However, the composite fluted web 58 also has utility for other applications, such as a substitute for the ubiquitous styrofoam peanuts used as packaging filler and cushioning material.
An alternate apparatus for forming a fluted web is shown schematically in
Although a single wall composite web, having one fluted web and one smooth web, can be utilized in the overall process of the present invention, it is preferable to use an open face double wall web such as web 25 used in the process described with respect to
Another embodiment of a system for carrying out the process for the continuous manufacture of open core elements is shown in
The web 60 is slit in a multi-blade slitting knife 62 into open face double wall strips 63 with the flutes oriented upwardly. As with the previously described process and methods, the width of the strips 63 determines the height or thickness of the finished open core elements. The strips 63 move from the slitting knife under a glue roll 64 where glue is applied to the exposed flute tips. However, in this embodiment one strip is left unglued. The unglued strip 65 may be provided in a number of ways, such as using a laterally movable scraper blade operatively engaging the glue roll to prevent glue from being applied to the unglued strip 65. Successive unglued strips 65 are placed among the strips exiting the glue roll to space between them a selected number of glued strips 63 desired in the finally formed core element. Thus, the unglued strips 65 may not always be in the same lateral position on the strips exiting the glue roll 64 because the desired core element may utilize more or less than the total number strips 63 slit from the incoming web 60.
Each group of strips 63 exiting the glue roll is accelerated on a speed-up conveyor 66 to separate the strips from the next incoming group of strips. The strip group 68 is then cross-transferred onto a lateral feed conveyor 67 where each of the strips now extends laterally across the feed conveyor 67. At the downstream end of the lateral feed conveyor 67, a strip upender 35 identical to the one described with respect to the preceding embodiment, operates to sequentially reorient each strip 63 from a horizontal to a vertical position. Each reoriented strip is positioned with its glued flute tips extending vertically and facing in the downstream direction and is brought into contact with the smooth web on the back of the preceding strip 63.
Referring to
Instead of utilizing an unglued strip 65, it is also possible to insert an unglued sheet of paper 84 which adheres to the glued flute tips of the facing strip and becomes part of the core element 70. Alternately, the face of the downstream compactor plate 73, in the previously described embodiment, may be coated with a non-stick material.
In an alternate method for compacting the formed core elements 70, the element forming conveyor 72 may be angled downwardly to utilize the force of gravity to help press the strips 63 together. In addition, a weighted plate may be inserted against the smooth web face of the rearmost strip of the core element 70.
In a presently preferred apparatus for forming flutes in a continuous web, reference is made to
A lower rotary counterroll 91 is mounted and positioned for counterrotational engagement with the fluting roll 85. Typically, the upper fluting roll 85 is the driving roll and the counterroll 91 is the driven roll. The nominal diameter of the counterroll 91 may be 8″ (about 203 mm). The counterroll 91 also has a rigid cylindrical interior shell 92, but it is covered on its exterior with an elastomer sleeve 93, preferably made of a relatively hard rubber, such as conventional die rubber. Imbedded in the elastomer sleeve 93 are a plurality of circumferentially spaced fluting bars 94 having round outer tips 95 circumferentially spaced at the pitch of the fluting roll 85. As may be seen in the drawings, the fluting bars 94 have a sort of tear drop cross sectional shape and are preferably made from hollow aluminum extrusions. The fluting bars 94 and the flute teeth 87 of the fluting roll 85 extend axially together and parallel to one another the full width of the rolls 85 and 91, which conveniently may be 96″ (about 245 cm). However, axial roll length is not critical and the rolls may be made with any length suited to the web material on which they operate.
The flute teeth 87 of the fluting roll 85 are generally V-shaped in cross section with the gullets 90 having a circular cross section. The tips 88 also have a circular cross section. The flute teeth 87 have flat flanks 96 between the tips and gullets. It is significant in the formation of large pitch flutes in a web 97, as shown in
Preferably, the tips 95 of the fluting bars 94 have a radius slightly less than the radius of the flute teeth gullets 90 of the fluting roll 85. Typically, for a web 97 of a given thickness, radius of the fluting tips 95 is less than the radius of the flute teeth gullets 90 by an amount approximately equal to the web thickness, e.g. 0.009″ (0.23 mm). Instead of circular cross section tips 88 and 95 on the fluting roll teeth 85 and fluting bars 94, respectively, a compound radius may be used.
The rubber sleeve 93 in which the fluting bars 94 are embedded serves two important functions, in addition to providing firm support for the bars. First, if the lower counterroll 91 were made with the fluting bars 94 rigidly attached to the steel shell 92, the vertical radial distance between the two roll centers, as the paper web 97 passes through the fluting nip, is forced to change. Without the cushioning effect provided by the rubber sleeve 93, the rigid steel rolls would be forced to deflect, resulting in high vibration and noise and, quite possibly, damage to the web. For example, using a 16″ diameter fluting roll 85 and an 8″ diameter counterroll 91, referring to
In addition, after the fluting bar 94 passes the top dead center position (moving from
To assist in formation of the flutes 98, it is desirable to provide vacuum to the gullets 90 of the upper roll flute teeth 87. Vacuum is supplied through a series of circumferentially spaced, axially extending vacuum bores 102 in the fluting roll shell 86. With appropriate internal valving, the vacuum is preferably applied at the point of flute formation, as shown in
It may also be desirable to heat the fluting roll 85 by supplying steam to a circumferentially spaced, axially extending series of steam bores 104 formed in the fluting roll shell 86. As shown, the steam bores 104 alternate circumferentially with the vacuum bores 102. However, any convenient arrangement may be used. The heat applied to the roll 85 and the web 97 helps precondition the fluted web for downstream application of an adhesive, such as a starch-based glue, to the flute tips of the fluted web 103, as will be described in more detail below.
Because in some applications it may be desirable to waterproof a paper web 97, the heated fluting roll 85 may assist in drying a liquid adhesive applied to the web 97 before fluting. For example, if an A-phase phenolic resin is applied to the paper web, it is dried to a B-phase before fluting.
In accordance with the overall system of the present invention for producing open core elements, fluted webs are joined with an adhesive to plane unfluted webs in various steps of the operation to progressively form the open core elements as shown schematically in
In
A presently preferred pump 106 comprises a ganged array of positive displacement pumps commonly driven to provide laterally spaced beads of adhesive to the glue roll 110 of the glue roll assembly 107. Preferably, the pump 106 comprises a ganged peristaltic pump which receives a supply of a liquid adhesive to the inlet ends 111 of laterally spaced flexible tubes 112 made of a suitable synthetic rubber, such as neoprene. The tubes extend through the pump 106 and terminate in outlet ends 113 evenly spaced laterally across the surface of the glue roll 110. The pump 106 may, for example, have 24 supply tubes 112 and, if the adhesive is being applied to a 48″ web, the tubes 112 would be spaced at about 2″ intervals.
The pump 106 includes a supporting frame 114 that has a semicylindrical backing surface 115 and a driven rotating roller assembly 116 that has an axis of rotation coincident with the axis of the backing surface 115. In the embodiment shown, there are four laterally spaced roller assemblies, each of which carries three orbitally mounted rollers 117. The adhesive supply tubes 112 extend from an upstream tube harness 118 downwardly between the backing surface 115 and the roller assembly 116 to the outlet ends 113 of the tubes adjacent the surface of the glue roll 110. Rotation of the orbital rollers 117 brings individual rollers sequentially into contact with the tubes 112, squeezing them against the backing surface 115 and pushing accurately metered amounts of liquid adhesive through the tubes to the outlet ends 113. By carefully controlling the supply of liquid adhesive to the inlet ends 111 of the tubes 112, the pre-calculated exact volume of adhesive desired to be applied to the web is delivered by the pump to the glue roll. In this manner, the pump supplies only the volume of adhesive needed and there is no need to recirculate unused adhesive which could be contaminated or otherwise unsatisfactory for reuse. Once the starch formula has been used to calculate the mix of starch and water (with other well known additives), the volume to be supplied to the pump and the transferred to the glue roll is calculated based on pump rotational speed, web speed and web width. One important benefit of utilizing a peristaltic pump apparatus is that none of the pump mechanism, except the tubes 112, is contacted by the adhesive. This minimizes adhesive build up on internal parts and facilitates considerably the cleaning of the glue machine, as will be described.
The outlet ends 113 of the adhesive supply tubes 112 are attached to a tube outlet support assembly 120 extending across the width of the glue machine 105 above the glue roll 110. The glue roll assembly 107 includes a flexible adhesive spreading tongue 121 that has its upper edge attached to a tongue support 122 and a free downstream end 123 that is shaped to lie against and conform to the cylindrical surface of the glue applicator roll 110. The beads of liquid adhesive supplied to the glue roll surface upstream of the shaped end 123 of the spreading tongue 121 are smoothed into a uniform layer on an engraved surface on the glue roll 110 from which it is applied to the flute tips of the incoming web 108 that makes tangent contact with the glue roll 110.
The outlet ends 113 of the adhesive supply tubes 112 are mounted on the support assembly 120 such that their positions can be selectively adjusted to a desired spacing in order to accommodate different width webs 108. In the embodiment shown in
The glue machine 105 also includes a laterally adjustable adhesive width control assembly 127 that includes a pair of laterally adjustable doctor blades 128 which may be moved into contact with the glue roll surface to remove unneeded adhesive and to define the width of the glue layer to be applied to the incoming web 108. The doctor blades 128 are slidably mounted on a lateral support member 130 and each doctor blade assembly includes a vacuum connection 131 to carry unused glue away. When the glue supply from the pump 106 is terminated, the inlet ends 111 of the glue supply tubes 112 are supplied with a cleaning fluid that travels through the tubes, onto the glue roll and mating face of the spreading tongue 121 and over the cleaning doctor blade 133.
It is also preferable to mount the adhesive supply tubes 112 so they can be adjusted axially in the tube harness to change their positions to present different areas to contact by the pump rollers 117. In this manner, the points at which constant intermittent squeezing of the tubes occurs can be changed to present fresh unstressed tube portions to the rollers.
This is a continuation-in-part of application Ser. No. 11/476,474, filed Jun. 28, 2006.
Number | Date | Country | |
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Parent | 11476474 | Jun 2006 | US |
Child | 11769879 | US |