Abstract:
A release liner staging unit for depositing a release liner onto an adhesive layer. The unit includes an accumulator that creates a buffer between an amount of release liner supplied and an amount needed for covering a layer of adhesive. The tendency of release liner placed within the accumulator to settle allows additional release liner to be introduced, thereby producing a slightly saturated level of release liner in the accumulator. Time delays can be accounted for to reduce the number of times a drive mechanism needs to operate, thereby reducing wear on such componentry. The unit may also form part of a larger release liner application device and adhesive application system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is based on U.S. provisional application Ser. No. 60/565,646, filed Apr. 27, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention relates generally to a device for applying a release liner to an adhesive that is disposed on a substrate, and more particularly to an improved accumulator that regulates the tension in the release liner as the liner is being applied.  
         [0003]     Automated gluing systems are routinely used to affect high-speed, repeatable application of adhesives to various substrates such that upon contact between the adhesive-containing substrate and another surface, a bond or seal is formed. Such systems are employed in deferred-use packaging, where a pressure-sensitive adhesive is covered with a release liner such that upon subsequent removal of the release liner and placement of the exposed adhesive in contact with a desired surface, the surface on which the adhesive is placed and the desired surface can be joined. In one form, the adhesive is integrated into a double-sided transfer tape that can be placed onto a substrate, where the side of the tape facing away from the substrate retains its layer of release liner to prevent the adhesive from being exposed until needed. While the transfer tape generally performs well, it is expensive and, due in part to its multiplicity of layers, very bulky. In another popular form, the adhesive is placed in a hot-melt liquid form onto a substrate, then covered with a layer of release liner. The hot melt approach is advantageous over the transfer tape approach because the lower bulk permits longer run-times between replenishment of the adhesive and release liner. In addition, the material costs are considerably lower than for transfer tape-based systems. Both the hot-melt approach and the transfer tape approach have been used extensively in the manufacture of paper and related products, such as corrugated cardboard sheet.  
         [0004]     In a conventional gluing station utilizing the hot-melt approach, the sheet is fed adjacent an aligned valve and nozzle such that upon actuation of the valve, a stream of the adhesive is deposited onto the desired location on the sheet through the nozzle. Downstream of that, a release liner application station places a layer of release liner (such as a silicone-coated film or tape) on top of the adhesive to protect it. One shortcoming of existing release liner application stations is that the liner tape or film is pulled from a roll that exhibits inertial effects that can alternately place too much or too little tension on the release liner. In situations involving too much tension on the liner, the concomitant pulling produces a tendency in the liner to slide out of the desired position on the underlying adhesive. Similarly, in situations involving too little tension, the liner can become slack, such that when tension is restored, a snapping motion can ensue, enhancing the possibility of liner breakage, especially in situations where the liner is very thin in order to keep cost and bulk down. Accordingly, what is needed is a way to buffer the supply of release liner so that it can be applied intermittently and at low tension to a layer of adhesive disposed on a substrate.  
       SUMMARY OF THE INVENTION  
       [0005]     This need is met by the present invention, wherein a release liner not subject to the inertial effect inherent in a conventional supply roll can be placed over adhesive for deferred use applications. According to an aspect of the invention, a release liner staging unit that can be filled with release liner is disclosed. The unit includes an accumulator with an inlet, a release liner storage compartment and an outlet to allow release liner to be at least temporarily stored in the accumulator. In the present context, an accumulator functions as a temporary storage or collection site for release liner. In this way, tension-producing inertial effects associated with a constantly-moving supply of release liner are reduced, as the release liner can (even if for only a brief moment) be stored in the accumulator without being pulled by a workpiece or a downstream component. This allows for rapid acceleration and deceleration of the release liner without a high level of tension in the liner. The unit also includes a drive mechanism to selectively advance release liner into the accumulator. One feature of the drive mechanism is that its operation involves a measure of hysteresis such that it continues to introduce release liner into the storage compartment even after attainment of a predetermined level of release liner therein. This produces a saturated level of release liner that results in lower amounts of drive mechanism cycling. The design of the release liner staging unit ensures that inertial effects are low, allowing liner to be intermittently pulled from the unit under rapid acceleration and deceleration, yet under low tension.  
         [0006]     Optionally, the thickness of the release liner staging unit is only slightly greater than the width of the release liner, thereby inhibiting twisting of the liner when situated in the liner storage compartment. Thus, by limiting the paths for air resident in the accumulator to circulate, this has the additional benefit of forming an air cushion to inhibit the formation of an overly dense stacking of release liner in the accumulator. Furthermore, the width of the unit can be made variable to accommodate release liner of differing widths, where a combination of spacers and panels that mount in the box take up the excess space that would cause the liner disposed in the unit to fall to the side. In addition, the unit may include access regions to facilitate cleaning, threading of the liner or the like. Moreover, anti-static devices (such as tinsel) can be placed at the inlet to prevent static from building up on the roll of web, where static can cause the loops of release liner to not fall into a correct serpentine pattern in the unit due to an adhesion of the release liner to electrically-chargeable plastic components (such as a door) situated at the unit inlet.  
         [0007]     In one form, the release liner advancing member is a drive roller, where a guide plate cooperates with the drive roller. In a particular form, the guide plate comprises at least one projecting finger and the drive roller comprises a complementary groove such that the guide plate and the drive roller cooperate to inhibit wrapping of the release liner around the drive roller. An anti-backlash roller clutch has a rubber-coated non-driven nip roller with the ability to promote adjustable tension. The clutch prevents the roll from rotating backward due to the weight of the full reel of release liner that would otherwise cause the web to create slack and consequent misalignment or breakage on the driven roller. The drive mechanism may include a brake that upon engagement inhibits movement of a liner supply device (the latter of which may be in the form of a spool as discussed below) from coasting. One form of the brake is a pneumatic brake. An air bleed valve can further be included to provide a blast of low-pressure air to keep the release liner tape lower in the unit so that the serpentine loops occur in a more organized fashion, thereby reducing the risk of a double feed through the output slot. In the present context, a double feed occurs when an upstream folded-over portion of the liner gets fed through the outlet along with downstream portions of the liner. Upon dispensing of this upstream portion of the liner, a snapping motion could cause the liner to break.  
         [0008]     The outlet, which is preferably formed in a bottom side plate of the accumulator, can be adjusted to control the tension created on the outlet of the unit. In one form, the dimensions of an orifice at the outlet can be tightened or loosened. For example, when the dimension of the outlet is tightened, the release liner pulls through the outlet with more tension. In addition, the outlet may define a tortuous path to for example promote additional resistance to release liner movement when no pulling tension is being applied. In addition, a plurality of release liner outlets may be disposed in the accumulator, thereby permitting orientation of the accumulator to coincide with that of other componentry useable in the dispensing of release liner. In a preferred embodiment, the tortuous path defines a chevron shape. The release liner staging unit may also include a controller with one or more sensors configured to detect a quantity of release liner in the accumulator. A feedback mechanism can be used to operate a motor (or related means for turning the drive roller) and the brake upon receipt of an appropriate signal from the sensor. In a more particular form, the controller is coupled to a time delay relay to promote hysteresis in the filling of the accumulator with release liner.  
         [0009]     According to another aspect of the invention, a device is disclosed. In addition to the release liner staging unit discussed in conjunction with the previous aspect, the device includes a liner supply device and a liner affixing device configured to dispense the release liner from the release liner staging unit. As with the previous embodiment, movement of release liner may be by a motor coupled to a roller or related release liner advancing member. Optionally, the device includes an adhesive dispenser configured to place adhesive on a substrate. In another option, the liner supply device comprises a spool. The spool further comprises a plurality of retaining disks to promote substantial alignment of the release liner. In the present context, the term “substantial” and its variants are utilized to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. As such, it refers to an arrangement of elements or features that, while in theory would be expected to exhibit exact correspondence or behavior, may in practice embody something slightly less than exact. The term also represents the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. These spool retaining disks can be placed at axial ends of the roll&#39;s core, thereby preventing the lateral slippage and release of the liner due to side loads, surface irregularities or skewed pulled to one side by the release liner application device. One or more spacers may be disposed between the retaining disks, thereby allowing differing widths of the release liner to be placed on the spool. Regarding the spool, it may include an air chuck to promote ease on spool loading and unloading. The air chuck allows the user to release compressed air for selective engagement of reels of release liner. Furthermore, at least two of the rollers can be placed in contact with one another to form an adjustable tensioning device. In addition, at least one of these cooperating rollers can include a knurled surface to facilitate threading of the liner. A guide plate incorporating anti-wrap fingers can be placed inside grooves in the driven roller at the unit inlet. The fingers prevent loops of release liner from winding up around the driven roller and otherwise causing the web to break. In another option, the release liner staging unit is substantially aligned with the supply of release liner along the liner&#39;s lengthwise dimension.  
         [0010]     In yet another option, the device includes one or more sensors to monitor release liner parameters, such as movement or the presence of the liner. Such sensors can be signally coupled to a controller. In one form, the sensors can monitor for a break in the release liner; upon such sensing and subsequent signal sent the controller, the device can be shut down. A time delay relay may also be included to control the delay between the time that the sensor indicates the presence of release liner in the unit and when a feed motor supplying release liner to the unit is shut off. This delay allows the unit to be more densely filled in the accumulator, thus reducing the unit&#39;s duty cycle. A pneumatic brake can be included to stop the roll from supplying release liner to the unit, thereby avoiding “coasting” that would otherwise create slack that could break the web when the device starts feeding again. Optionally, the device may further include an air chuck that allows the user to release compressed air for engaging and disengaging the hub holding the reels of release liner.  
         [0011]     According to another aspect of the invention, a method of affixing a release liner onto an adhesive layer is disclosed. The method includes arranging a substrate to have the adhesive layer disposed on it, selectively feeding and storing a supply of release liner to an accumulator, moving at least a portion of the release liner stored in the accumulator to a position adjacent the adhesive layer disposed on the substrate, and covering at least a portion of the adhesive layer with the release liner. The accumulator functions in a manner similar to that of the previously-described aspects.  
         [0012]     Optionally, storing the selectively fed release liner includes storing it in a substantially serpentine pattern in the accumulator&#39;s storage compartment. In another option, a drive mechanism is operated to effect feeding of the release liner, where the drive mechanism includes a motor, one or more drive roller responsive to the motor such that they movably contact the release liner, and a brake cooperative with the motor. The brake and motor can work together such that when the motor is turning the drive roller, the brake is preferably disengaged, thereby not substantially inhibiting the movement of the release liner into the accumulator. Contrarily, when operation of the motor ceases, the brake engages the release liner to slow down or stop movement of the release liner into the accumulator. A controller may be coupled to the drive mechanism and the accumulator such that upon detecting an absence of release liner in the accumulator, the controller can instruct the motor to introduce additional release liner into the accumulator. The aforementioned hysteresis to produce the saturated level in the storage compartment can be achieved by having a time delay protocol built into the controller. For example, an appropriate time delay relay can be used to effect such hysteresis. In addition, a liner affixing device can be used to dispense the release liner from the accumulator. Furthermore, adhesive may be applied on a substrate such that upon a downstream passage of the adhesive by the liner affixing device, the liner covers at least a portion of the adhesive placed on the substrate.  
         [0013]     According to still another aspect of the invention, a method of reducing inertial effect from a supply of release liner is disclosed. The method includes selectively feeding release liner to an accumulator, storing the release liner in a substantially serpentine pattern in the accumulator, measuring an amount of space in the storage compartment occupied by the release liner and operating a time delay cooperative with the measuring such that after the amount of space occupied by the stored release liner drops below a predetermined threshold, additional release liner is introduced into the accumulator to saturate a level of release liner therein. In one optional form, either a fixed-speed or a variable-speed drive mechanism (for example, a variable speed motor or related means for operating a release liner advancing member) could be incorporated to facilitate feeding release liner to the accumulator. Such a drive mechanism could be similarly used in conjunction with the devices of the previously-described aspects. Use of a variable-speed drive mechanism could promote continuous (rather than stop-start) operation, where a quiescent operating point could be established. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0014]     The following detailed description of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:  
         [0015]      FIG. 1  is a front elevation view of a system for applying adhesive and a release liner onto a substrate according to the prior art;  
         [0016]      FIG. 2  shows a front elevation view of a release liner application system incorporating an accumulator according to the prior art;  
         [0017]      FIG. 3A  shows a front elevation view of a system including an adhesive application device, release liner application device and release liner staging unit according to an aspect of the present invention;  
         [0018]      FIG. 3B  shows a top view of a portion of the system of  FIG. 3A ;  
         [0019]      FIG. 3C  shows a detail view of an outlet of the release liner staging unit of  FIG. 3A ;  
         [0020]      FIG. 3D  shows a perspective view of a drive roller and corresponding guide plate according to an aspect of the present invention;  
         [0021]      FIG. 3E  shows an elevation view of the engagement of the drive roller and corresponding guide plate of  FIG. 3D ;  
         [0022]      FIG. 3F  shows a rear elevation view of the release liner staging unit of  FIG. 3A ;  
         [0023]      FIG. 3G  shows a side elevation view of the release liner staging unit of  FIG. 3A ; and  
         [0024]      FIG. 4  shows a perspective view of a simplified release liner application device. 
     
    
     DETAILED DESCRIPTION  
       [0025]     Referring first to  FIG. 1 , an adhesive layer and release liner application system  10  according to the prior art is shown. The system  10  sequentially places an adhesive layer  2  and a release liner  3  onto a moving substrate  1 . In one configuration, the adhesive layer  2  is a hot melt adhesive that is deposited in viscous liquid form, while the release liner  3  is a relatively thin (on the order of a few mils or less) film of silicone coated paper or similar non-adherent material. The substrate is a generally planar paper, plastic or cardboard material which, after adhesive deposition, can be folded or stacked for subsequent use. The system  10  includes an adhesive application device  20 , spool  30  of release liner and a release liner application device  40  with numerous rollers  42 . Adhesive application device  20  typically includes a vat to store the adhesive, as well as related heating devices and conduit to liquefy and transport the adhesive to one or more deposition nozzles.  
         [0026]     Referring next to  FIG. 2 , a variation on the prior art adhesive layer and release liner application system  10  is shown, where in addition to the aforementioned spool  30  of release liner and release liner application device  40  (presently shown in more detail) with numerous rollers  42 , there is an accumulator  70  used as a buffer to avoid improper feeding of release liner  3  during operational transients. The accumulator  70  is in the nature of a passive box, in that it merely acts as a temporary storage place for release liner  3 ; it possesses no ability to match the liner needs of release liner application device  40  to the supply needs of spool  30 . Motor  50  turns a drive roller  93  to coax release liner  3  into the accumulator  70 , while a pivoting dancer arm  60  can be used to match the delivery of release liner  3  to accumulator  70 . Inlet  70 A and outlet  70 B are mounted on the side of accumulator  70  to allow horizontal ingress and egress of release liner  3 . When a supply of release liner  3  is no longer required, such as through a limit reached inside the accumulator  70 , a lever arm  72  moves, activating fill switch  71  and causing motor  50  to be turned off. Nevertheless, frequent cycling of the motor  50  can cause compatibility problems with the accumulator  70 , especially in terms of misfeeding release liner  3  through inlet  70 A and outlet  70 B. An additional shortcoming of system  10  when equipped as shown is that the dancer arm  60  has different response characteristics over the course of spool  30  depletion. For example, its spring response rate may be optimized for a spool  30  that is relatively fresh, but grossly mismatched as the diameter of the spool  30  decreases. Such performance can lead to snapping movement that could cause the release liner  3  to break, as well as overfilling the accumulator  70 , thus defeating the purpose of the accumulator  70 . In addition, relatively heavy gauge liner must be used, as otherwise the lever arm  72  and fill switch  71  will not respond until the serpentine buildup of liner  3  in the accumulator  70  has become excessive.  
         [0027]     Referring next to  FIGS. 3A through 3G , an adhesive layer and release liner application system  110  is disclosed. The system  110  includes an adhesive application device  120 , spool  130  of release liner  3 , release liner application device  140  and release liner staging unit  170  with inlet  170 A, outlet  170 B and accumulator (also referred to as an accumulation chamber, chamber or a release liner storage compartment)  170 C (which defines the interior, liner-storing portion of the housing that makes up release liner staging unit  170 ) between the inlet and outlet. Substrate  1  is moved, such as by conveyor (not shown), sequentially underneath adhesive application device  120  and release liner application device  140 , picking up adhesive  2  and release liner  3 , respectively. Release liner  3  is supplied to release liner application device  140  from spool  130  through inlet  170 A, where it passes between drive roller  193  and an adjacent idler roller  192  to be stored in accumulation chamber  170 C until needed by release liner application device  140 , at which time it is pulled through outlet  170 B in bottom side plate  172  of the housing. The configuration of the release liner in storage compartment  170 C is such that it assumes a substantially serpentine pattern as shown in the figure. Spool retaining disks  180  over spool  130  and a door panel  240  used to cover accumulation chamber  170 C serve to keep release liner  3  from becoming axially misaligned. In one embodiment, the door panel  240  may be made from a transparent material (such as Lexan® or acrylic) so that an individual monitoring the operation of the release liner application system  110  can visually verify that the storage of release liner  3  in accumulation chamber  170 C is being done properly. In addition, spacers (not shown) can be added such that door panel  240  can be mounted to accumulation chamber  170 C in differing widths, thereby accommodating release liner  3  of differing widths.  
         [0028]     Main power box  153  includes a switch to turn the release liner staging unit  170  on and off, while sensor  210  is placed in accumulation chamber  170 C to detect when the chamber reaches a predetermined fill level. A controller (which may, for example, be microprocessor-based, and made up of numerous components) may be used to establish a circuit used to coordinate operation of the motor  150  and pneumatic brake  160  in response to detected signals from sensor  210  or other related detector. In one configuration, the controller may include a power source (such as main power box  153 ), sensor  210 , associated circuitry, and related components, such as the time delay relay  155  (discussed below). The controller acts through a feedback mechanism to automatically stop and start the motor  150  and brake  160  as needed. For example, if the accumulator  170 C is filling up with release liner  3 , and upon receipt of an appropriate (either manual or detected) signal, the controller instructs motor  150  (discussed below) to stop and causes a pneumatic brake  160  (also discussed below) to engage. An anti-static tinsel device  225  can be placed just upstream of drive roller  193 .  
         [0029]     Referring with particularity to the top view of  FIG. 3B , the connection of the motor  150  to drive roller  193  through rear wall  174 , as well as the connection of pneumatic brake  160  to spool  130 , is shown. Together, motor  150  and rollers  192 ,  193  make up a release liner drive unit  200  to ensure that, upon an appropriate signal, more release liner  3  is either fed into or prevented from entering into the accumulation chamber  170 C. The aforementioned controller and sensor  210  may also form part of the drive unit  200 , or may be separate components configured to cooperate with the drive unit  200 . Similarly, motor  150  may form either an integral component of drive unit  200 , or may be a separate component that that can be made to turn drive roller  193  on an as-needed basis. Pneumatic brake  160  can be made to cooperate with the drive unit  200  to ensure smooth, coordinated operation, thereby avoiding excessive release liner  3  buildup in accumulator  170 C and snapping of the release liner  3  upon startup of motor  150 . Brake mounting extension arm  175  rigidly couples the pneumatic brake  160  and spool  130  to rear wall  174  of release liner staging unit  170 . Drive roller  193  includes grooves  194  the use of which will be discussed in more detail below. Pneumatic brake  160  is coupled to spool  130  through idler shaft  260 , while spool  130  is mounted to a pneumatic chuck  135 , which includes an inflatable core to allow quick mounting and dismounting of spool  130 . A pair of spool retaining disks  180  as previously discussed are spaced along pneumatic chuck  135  to provide lateral support to release liner (not presently shown).  
         [0030]     Motor  150  and pneumatic brake  160  are responsive to sensor (for example, a light sensor)  210  shown in  FIG. 3A  such that upon the level of release liner  3  stored in accumulator  170 C falling below a threshold determined by sensor  210 , the controller instructs motor  150  to commence, thereby turning drive roller  193  (which may include a relatively high friction surface to better engage the release liner  3 ) to pull release liner  3  from spool  130  until enough release liner  3  is replenished in chamber  170 C, at which time motor  150  is stopped, and pneumatic brake  160  can be activated. By the coordinated operation of the motor  150  and pneumatic brake  160  to ensure a smooth flow of release liner  3 , dancer arms (such as those discussed in conjunction with the prior art) can be removed or their operation simplified.  
         [0031]     Referring with particularity to  FIGS. 3F and 3G , a time delay relay  155  is coupled to pneumatic brake  160  and motor  150  through a series of tubing  228 , valves  229  and regulator  230  to effect a hysteresis-like response in filling chamber  170 C with release liner  3 . The presence of an air cushion that is made possible by the relatively close fit between the release liner  3  and its lateral support in the release liner staging unit  170 , coupled with the relatively compliant nature of the serpentine storage profile (as shown in  FIG. 3A ) assumed by release liner  3  when disposed in chamber  170 C, is such that after a period of time, the release liner  3  settles (such as due to the weight of later-added liner onto the earlier-added liner within the chamber  170 C, as well as the gradual escaping of air between the serpentine layers), thereby increasing the amount of available space in the chamber  170 C available for storing release liner  3 . By using time delay relay  155  and the ancillary equipment discussed above, this hysteresis can be exploited to delay the onset of motor  150  stoppage and pneumatic brake  160  deployment to allow the chamber  170 C to slightly saturate, thereby reducing the duty cycle (including concomitant heat buildup) of the motor  150  and pneumatic brake  160  and extending the life of these components. In a slightly saturated configuration, the release liner storage compartment  170 C of the accumulator is overfilled enough to slightly compress the relatively compliant stack of release liner  3 , but not so great as to cause the release liner  3  to crimp, crease, twist or otherwise lose its ability to maintain a discontinuity-free profile. In addition, a backlash roller clutch (using, for example, needle bearings (not shown) inside idler roller  192 ) may be included to cooperate with idler roller  192 . The operation of pneumatic brake  160  is such that it prevents the spool  130  from coasting, which would otherwise lead to slack developing in the release liner  3  during periods of system  110  inactivity, slack that upon reactivation of the system  110  could produce a snapping effect in and possible damage to the liner.  
         [0032]     Referring next to  FIG. 3C , a detail view of outlet  170 B of release liner staging unit  170  is shown. The lowermost portion of chamber  170 C is defined by bottom side plate  172 . Rather than having a straight-through passage of bottom side plate  172 , a tortuous path is formed, thereby inhibiting the tendency of the release liner  3  from being forced through outlet  170 B during periods of system inactivity. In the present context, a tortuous path includes any such path that involves at least one significant change in direction (for example, an angle change of between ninety and two hundred and seventy degrees) or multiple changes of direction the cumulative effect of which is to significantly hamper the ability of a release liner  3  not under an external pulling force (i.e., a pulling force other than that associated with the gravity of the portion of the release liner already below the bottom outlet  170 B) to continue passing through bottom outlet  170 B. In the version shown, the tortuous path defines a sideways chevron shape. It will be appreciated by those skilled in the art that the bottom outlet  170 B could also involve a serpentine shape. The bottom outlet  170 B is more conducive to smooth delivery of release liner  3  to the application device  140  than the side-mounted exit of the prior art, while the tortuous path of bottom side plate  172  reduces the likelihood of inadvertent release of the liner during periods where there is no demand from the substrate  1 . The accumulator  170 C needs to be reversible, depending on the feed direction of the release liner  3 . Thus, although not presently shown, it will be appreciated by those skilled in the art that the accumulator  170 C can have an outlet  170 B at each side of bottom side plate  172 . This would allow one accumulator  170 C to be used on either side of a release liner application system. In certain instances, it may be necessary to pass spliced release liner. Bottom outlet  170 B could be made larger to accommodate the increased thickness of such a splice, although not so large as to promote the free-flow gravity feed of release liner. In an alternative approach, bottom outlet  170 B can be made adjustable via spring-loaded or other self-adjusting features. In this way, bottom outlet  170 B could be both compatible with splices as well as avoid the inadvertent release of liner during periods where there is no demand.  
         [0033]     Referring with particularity to  FIGS. 3D and 3E , the relationship between drive roller  193  and guide plate  244  is shown. Drive roller  193  may include a series of grooves  194  that allow complementary-shaped anti-wrap fingers  245  that are cantilevered from guide plate  244  to cooperate with one another. The fingers  245  are biased to keep contact between them and the grooves  194  of drive roller  193 , thereby deterring the release liner  3  from getting caught up and winding around drive roller  193 . Guide plate  244  can be mounted to appropriate structure within chamber  170 C.  
         [0034]     Referring next to  FIG. 4 , a perspective view showing the application of release liner  3  to an adhesive layer that has been placed on top of substrate  1  includes a simplified representation of release liner application device  140  with rollers  142 . As previously indicated, the release liner is made from a relatively non-stick material (such as silicone-coated paper) that allows ease of removal during a deferred-use application. By avoiding over-tensioning and related deformation of the release liner  3  through the use of saturating the accumulator of the of release liner staging unit  170 , the release liner will not pull away from or slide off the applied adhesive.  
         [0035]     While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention, which is defined in the appended claims.