Patent Application
20150375951
The present disclosure provides for attaching the tail to the body of a convolutely wound log of web material.
In the manufacture of rolled web products, such as bath tissue or paper towels, a winder winds a web of material to form a large parent roll. The parent roll is then subsequently unwound, subjected to a variety of conversions, such as embossing, and then rewound by a rewinder into a consumer diameter sized convolutely wound log. The convolutely wound log is eventually cut into consumer width sized rolls, such as bath tissue, paper towels and similar finished products. To efficiently process the convolutely wound log through converting processes, cutting and packaging, the loose end of the log (i.e., the tail) is often secured or sealed to the body (i.e., the non-tail portion) during a tail sealing process.
Common gluing, moistening and other systems known to those in the tail sealing art typically require some manipulation of the tail for correct alignment for adhesive application, proper winding or rewinding and the like. In most commercially available embodiments, the tail is laid flat and unwrinkled against the log with the tail being secured to the log at a position a short distance from the very end of the tail using an adhesive-based material. This tail sealing arrangement leaves a small length of the end of the tail unsecured (the so-called “tab”) to enable the end user to grasp, unseal and unwind the convolutely wound product.
The teal sealing process is typically used to aid in the downstream converting processes, such as to keep the roll from undesirably becoming unwound before it has been property packaged. As a consequence, however, the consumer is tasked with breaking the bond in order to use the rolled web product. Many known systems have been found deficient when attempting to obtain an amount of adhesion or type of adhesive that is sufficient for downstream manufacturing processes, yet not forming a bond that may be considered too strong from a consumer perspective. If the bond strength is too low, the processing difficulty may be experienced yet if the bond strength is too high, a consumer interacting with the wound roll may experience difficulty when attempting to separate the tail from the wound roll from the body. For example, if the strength of the bond is stronger than the web substrate, the web material may undesirably tear when a consumer attempts to separate the tail from the body. In such instances, the torn portions of the roll may be considered unusable and wasted, resulting in consumer dissatisfaction or frustration.
Moreover, known tail sealing systems often utilize adhesives that dry relatively slowly. It is desirable, however, that tail seal adhesive dry quickly so that the bond is properly set in advance of downstream converting operations (e.g., wrapping, bundling, and other manipulation). A log typically is processed through such processes in about 5-10 minutes. Yet, known systems utilize adhesives with drying times of more than an hour, which fully dry long after the product is cycled through the manufacturing processes. In some cases, the bond strength even continues to increase even after the wound roll has been discharged from the manufacturing process and has been packaged.
Additionally, using conventional adhesive-based tail sealing techniques, once the adhesive is applied to the wound roll and the bond is formed through evaporation, the bond strength of the adhesive cannot be reduced. Therefore, although the tail does not necessarily need to be adhered to the body with relatively high bond strength subsequent to the manufacturing process, conventional bonding techniques do not allow for selective reversibility of the bond strength.
Thus, it would be advantageous to provide for a tail sealing system that addresses one or more of these issues. Indeed, it would be advantageous to provide for a tail sealing method that provides sufficient bonding for downstream converting operations while reducing negative end user feedback during interactions with the roll. It would be also advantageous to provide a tail seal having a bond strength that can be selectively increased and/or decreased. Specifically, it would be desirable to provide a tail seal with a bond strength that can be increased for manufacturing processes and then subsequently decreased in order to allow a consumer to more easily separate the tail from the body of the wound roll.
The present disclosure fulfills the needs described above by, in one embodiment, providing a method for bonding the tail of a convolutely wound log of web material to the body of the log, where the method comprises providing a web material; winding the web material into a convolutely wound log having a body and a tail; providing a nonadhesive phase-change material in an amorphous phase; and applying the nonadhesive phase-change material in the amorphous phase to the web material at an application site proximate to the tail. The nonadhesive phase-change material alters to a non-amorphous phase to create a bond between the tail and the body.
In another embodiment, a method is provided for adhesively bonding a tail of a convolutely wound log of web material to the body of the log comprises providing a web material having a peak and a valley; winding the web material into a convolutely wound log having a body and a tail; providing a nonadhesive phase-change material in an amorphous phase; and applying the nonadhesive phase-change material in the amorphous phase to the web material at an application site proximate to the tail. The nonadhesive phase-change material alters to a non-amorphous phase to create a bond between the tail and the body.
In yet another embodiment, a convolutely wound material is provided having a tail and body, the tail being bonded to the body with a nonadhesive phase-change material
The present disclosure provides for methods of tail sealing a convolutely wound log of material using a nonadhesive phase-change material. Various nonlimiting embodiments of the present disclosure will now be described to provide an overall understanding of the principles of the function, design and use of the tail sealing methods as well as the tail sealed convolutely wound products disclosed herein. One or more examples of these nonlimiting embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the methods described herein and illustrated in the accompanying drawings are nonlimiting example embodiments and that the scope of the various nonlimiting embodiments of the present disclosure are defined solely by the claims. The features illustrated or described in connection with one nonlimiting embodiment can be combined with the features of other nonlimiting embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure.
“Fibrous structure” as used herein means a structure that comprises one or more filaments and/or fibers. Nonlimiting examples of processes for making fibrous structures include known wet-laid papermaking processes and air-laid papermaking processes. Such processes typically include steps of preparing a fiber composition in the form of a suspension in a medium, either wet, more specifically aqueous medium, or dry, more specifically gaseous, i.e. with air as medium. The aqueous medium used for wet-laid processes is oftentimes referred to as a fiber slurry. The fibrous slurry is then used to deposit a plurality of fibers onto a forming wire or belt such that an embryonic fibrous structure is formed, after which drying and/or bonding the fibers together results in a fibrous structure. Further processing the fibrous structure may be carried out such that a finished fibrous structure is formed. For example, in typical papermaking processes, the finished fibrous structure is the fibrous structure that is wound on the reel at the end of papermaking and may subsequently be converted into a finished product (e.g., a sanitary tissue product such as a paper towel product). The fibrous structures of the present invention may be homogeneous or may be layered. If layered, the fibrous structures may comprise at least two and/or at least three and/or at least four and/or at least five layers. The fibrous structures of the present disclosure may be co-formed fibrous structures.
“Fiber” and/or “Filament” as used herein means an elongate particulate having an apparent length greatly exceeding its apparent width (i.e., a length to diameter ratio of at least about 10). In one example, a “fiber” is an elongate particulate as described above that exhibits a length of less than 5.08 cm (2 in.) and a “filament” is an elongate particulate as described above that exhibits a length of greater than or equal to 5.08 cm (2 in.).
Fibers are typically considered discontinuous in nature. Nonlimiting examples of fibers include wood pulp fibers and synthetic staple fibers such as polyester fibers.
Filaments are typically considered continuous or substantially continuous in nature. Filaments are relatively longer than fibers. Nonlimiting examples of filaments include meltblown and/or spunbond filaments. Nonlimiting examples of materials that can be spun into filaments include natural polymers, such as starch, starch derivatives, cellulose and cellulose derivatives, hemicellulose, hemicellulose derivatives, and synthetic polymers including, but not limited to polyvinyl alcohol filaments and/or polyvinyl alcohol derivative filaments, and thermoplastic polymer filaments, such as polyesters, nylons, polyolefins such as polypropylene filaments, polyethylene filaments, and biodegradable or compostable thermoplastic fibers such as polylactic acid filaments, polyhydroxyalkanoate filaments and polycaprolactone filaments. The filaments may be monocomponent or multicomponent, such as bicomponent filaments.
In one example of the present disclosure, “fiber” refers to papermaking fibers. Papermaking fibers useful in the present disclosure include cellulosic fibers commonly known as wood pulp fibers. Applicable wood pulps include chemical pulps, such as Kraft, sulfite, and sulfate pulps, as well as mechanical pulps including, for example, groundwood, thermomechanical pulp and chemically modified thermomechanical pulp. Chemical pulps, however, may be preferred since they impart a superior tactile sense of softness to tissue sheets made therefrom. Pulps derived from both deciduous trees (hereinafter, also referred to as “hardwood”) and coniferous trees (hereinafter, also referred to as “softwood”) may be utilized. The hardwood and softwood fibers can be blended, or alternatively, can be deposited in layers to provide a stratified web. Also applicable to the present disclosure are fibers derived from recycled paper, which may contain any or all of the above categories as well as other non-fibrous materials such as fillers and adhesives used to facilitate the original papermaking.
“Sanitary tissue product” as used herein means a soft, low density (i.e., <about 0.15 g/cm3) web useful as a wiping implement for post-urinary and post-bowel movement cleaning (toilet tissue), for otorhinolaryngological discharges (facial tissue) and multi-functional absorbent and cleaning uses (absorbent towels). The sanitary tissue product may be convolutely wound upon itself about a core or without a core to form a sanitary tissue product roll.
The sanitary tissue products and/or fibrous structures of the present disclosure may exhibit a basis weight of greater than 15 g/m2 (9.2 lbs/3000 ft2) to about 120 g/m2 (73.8 lbs/3000 ft2) and/or from about 15 g/m2 (9.2 lbs/3000 ft2) to about 110 g/m2 (67.7 lbs/3000 ft2) and/or from about 20 g/m2 (12.3 lbs/3000 ft2) to about 100 g/m2 (61.5 lbs/3000 ft2) and/or from about 30 (18.5 lbs/3000 ft2) to 90 g/m2 (55.4 lbs/3000 ft2). In addition, the sanitary tissue products and/or fibrous structures of the present disclosure may exhibit a basis weight between about 40 g/m2 (24.6 lbs/3000 ft2) to about 120 g/m2 (73.8 lbs/3000 ft2) and/or from about 50 g/m2 (30.8 lbs/3000 ft2) to about 110 g/m2 (67.7 lbs/3000 ft2) and/or from about 55 g/m2 (33.8 lbs/3000 ft2) to about 105 g/m2 (64.6 lbs/3000 ft2) and/or from about 60 (36.9 lbs/3000 ft2) to 100 g/m2 (61.5 lbs/3000 ft2).
The sanitary tissue products of the present disclosure may exhibit a total dry tensile strength of greater than about 59 g/cm (150 g/in) and/or from about 78 g/cm (200 g/in) to about 394 g/cm (1000 g/in) and/or from about 98 g/cm (250 g/in) to about 335 g/cm (850 g/in). In addition, the sanitary tissue product of the present disclosure may exhibit a total dry tensile strength of greater than about 196 g/cm (500 g/in) and/or from about 196 g/cm (500 g/in) to about 394 g/cm (1000 g/in) and/or from about 216 g/cm (550 g/in) to about 335 g/cm (850 g/in) and/or from about 236 g/cm (600 g/in) to about 315 g/cm (800 g/in). In one example, the sanitary tissue product exhibits a total dry tensile strength of less than about 394 g/cm (1000 g/in) and/or less than about 335 g/cm (850 g/in).
In another example, the sanitary tissue products of the present disclosure may exhibit a total dry tensile strength of greater than about 196 g/cm (500 g/in) and/or greater than about 236 g/cm (600 g/in) and/or greater than about 276 g/cm (700 g/in) and/or greater than about 315 g/cm (800 g/in) and/or greater than about 354 g/cm (900 g/in) and/or greater than about 394 g/cm (1000 g/in) and/or from about 315 g/cm (800 g/in) to about 1968 g/cm (5000 g/in) and/or from about 354 g/cm (900 g/in) to about 1181 g/cm (3000 g/in) and/or from about 354 g/cm (900 g/in) to about 984 g/cm (2500 g/in) and/or from about 394 g/cm (1000 g/in) to about 787 g/cm (2000 g/in).
The sanitary tissue products of the present disclosure may exhibit an initial total wet tensile strength of less than about 78 g/cm (200 g/in) and/or less than about 59 g/cm (150 g/in) and/or less than about 39 g/cm (100 g/in) and/or less than about 29 g/cm (75 g/in).
The sanitary tissue products of the present disclosure may exhibit an initial total wet tensile strength of greater than about 118 g/cm (300 g/in) and/or greater than about 157 g/cm (400 g/in) and/or greater than about 196 g/cm (500 g/in) and/or greater than about 236 g/cm (600 g/in) and/or greater than about 276 g/cm (700 g/in) and/or greater than about 315 g/cm (800 g/in) and/or greater than about 354 g/cm (900 g/in) and/or greater than about 394 g/cm (1000 g/in) and/or from about 118 g/cm (300 g/in) to about 1968 g/cm (5000 g/in) and/or from about 157 g/cm (400 g/in) to about 1181 g/cm (3000 g/in) and/or from about 196 g/cm (500 g/in) to about 984 g/cm (2500 g/in) and/or from about 196 g/cm (500 g/in) to about 787 g/cm (2000 g/in) and/or from about 196 g/cm (500 g/in) to about 591 g/cm (1500 g/in).
The sanitary tissue products of the present disclosure may exhibit a density (measured at 95 g/in2) of less than about 0.60 g/cm3 and/or less than about 0.30 g/cm3 and/or less than about 0.20 g/cm3 and/or less than about 0.10 g/cm3 and/or less than about 0.07 g/cm3 and/or less than about 0.05 g/cm3 and/or from about 0.01 g/cm3 to about 0.20 g/cm3 and/or from about 0.02 g/cm3 to about 0.10 g/cm3.
The sanitary tissue products of the present disclosure may comprise additives such as softening agents, such as quaternary ammonium softening agents, temporary wet strength agents, permanent wet strength agents, bulk softening agents, lotions, silicones, wetting agents, latexes, dry strength agents, and other types of additives suitable for inclusion in and/or on sanitary tissue products.
The embodiments discussed herein may be utilized with a convolutely wound log of web material, such as a convolutely wound log of a fibrous structure. The fibrous structure may comprise a sanitary tissue product.
“Consumer-sized product unit” as used in herein means the width of a finished product of convolutely wound web material, as measured in the cross machine direction, as such product will be packaged, sold, distributed or otherwise provided to end users.
“Phase-change material” (PCM) as used herein means a substance that changes from a solid phase to an amorphous phase, and vice versa, as heat is absorbed or released. When the PCM is heated to above its transition temperature, the PCM generally behaves as a low viscosity Newtonian fluid. The transition temperature is the temperature at which a phase change from amorphous to non-amorphous occurs or where a remarkable change in viscosity from high viscosity to low viscosity occurs.
“Nonadhesive PCM” as used herein means a PCM is void or substantially void of glue or other types of adhesives. When used to bond web substrates, the nonadhesive PCM utilizes mechanical entanglement of fibers of each of the web substrates to form the bond. Further, unlike adhesive materials, a nonadhesive PCM does not rely on evaporation to transition from an amorphous phase to a non-amorphous phase.
“Application site” as used herein means the desired location at which a nonadhesive PCM is to be deposited on a web material. The application site may be located, for example, on the tail, the body (i.e., the non-tail portion of the log) or, the crevice where the tail and the body meet.
“Machine direction” or “MD” as used herein means the direction parallel to the flow of the web material through the manufacturing equipment.
“Cross machine direction” or “CD” as used herein means the direction parallel to the width of the manufacturing equipment and perpendicular to the machine direction.
The Z-direction is orthogonal both the machine direction and cross machine direction, such that the machine direction, cross machine direction and Z-direction form a Cartesian coordinate system.
“Line of Nonadhesive PCM” as used herein means a macroscopically linear shape that may be essentially continuous (or unbroken) or semi-continuous (wherein the line of Nonadhesive PCM is intermittent, such as a dotted line). In one embodiment, the line of Nonadhesive PCM extends in the cross machine direction. As used herein, a shape is “macroscopically linear” if, when viewed with the unaided human eye at a distance of about 12 inches, such shape appears to form a substantially straight line (continuous or semi-continuous) or a substantially repeating pattern (continuous or semi-continuous).
“Above”, “over”, “top”, “up”, “below”, “beneath”, “bottom” and “under” and similar orientational words and phrases, except upstream and downstream, as used herein to describe embodiments are to be construed relative to the normal orientation, where the floor is located in the Z-direction below, beneath or under a tail sealing apparatus and the ceiling is located in the Z-direction above or over a tail sealing apparatus. Articles expressed as being above, over, on top and the like are located (or moving) in the Z-direction closer to the ceiling than the items to which they are being compared. Similarly, articles expressed as being below, beneath or under and the like are located (or moving) in the Z-direction closer to the floor than their respective comparators. One of skill in the art will recognize that the relationship between the article and its respective comparator is more significant than the relationship between the article and the floor or the ceiling. As such, inverted arrangements of articles as disclosed herein are included within the scope of this disclosure. Said differently, to the extent such configurations are workable, this disclosure is intended to include an apparatus and/or method where everything expressed as “below” is inverted to be “above” and everything expressed as “above” is inverted to be “below” and similar reversals or inversions.
“Downstream” as used herein means a step or system occurring or present later in a processing continuum. “Upstream” as used herein means a step or system occurring or present earlier in a processing continuum.
Referring now to
As shown in
The in-feed rolls 210 initially rotate in the same direction but at mismatched speeds, with the upper in-feed roll 212 rotating faster than the lower in-feed (or vacuum) roll 214. The distance of upper in-feed roll 212 relative to lower in-feed roll 214 can be adjusted to accommodate the wound log 120 diameter. However, the upper in-feed roll 212 is typically positioned to create some interference with the wound log 120. When the wound log 120 is fed into the in-feed rolls 210, the wound log 120 may be controlled at the top and bottom log 120 positions because of the interference and rate of log 120 travel is controlled by the speed difference between the in-feed rolls 210. If there is too little or no interference, the wound log 120 could slide through the in-feed rolls 210. Conversely, if there is too much interference, the logs 120 may not feed into the in-feed rolls 210 correctly and could cause a jam up at the index paddle 200.
As the wound log 120 contacts the in-feed rolls 210, it is pulled into the nip between the in-feed rolls 210 by the differential speed. As the wound log 120 reaches the diagonal center of the in-feed rolls 210, it blocks the log in-feed rollers detector 216 (e.g., photo eye sensor) at which time the in-feed rolls 210 rotate at a matched speed. This holds the wound log 120 in position while an airblast nozzle 259 emits a stream of air to separate the tail 220 from the wound log 120 and positions the tail 220 flat onto the table 240 where a tail detector 260 (e.g., a photoelectric cell) becomes blocked by the tail 220. As the wound log 120 rotates and rewinds the separated tail 220, the tail detector 260 becomes unblocked when the edge of the tail 220 has been located.
After the edge of the tail 220 is detected, the tail 220 is rewound onto the wound log 120 until the edge of the tail 220 is directly underneath the body 130 of the wound log 120. The in-feed rolls 210 stop and reverse direction, which unrolls the tail 220 from the body 130. The tail 220 is held by vacuum to the lower in-feed roll 214 and follows the lower in-feed roll 214 as it is unwound until a calculated length of tail 220 has been separated from the body 130. The in-feed rolls 210 then stop and the upper in-feed roll 212 starts rotating back in the forward direction to eject the body 120 from the in-feed rolls 210. The tail length centerline controls the amount of tail 220 that is unwound from the wound log 120 and is typically adjusted to get the target tab length. The speed of in-feed rolls 210 can impact consistent tail detection. Higher speeds can reduce the time to rotate the wound log 120 but may not increase rate capability. The speed of in-feed rolls 210 can be adjusted to consistently detect the tail 220 on the first revolution.
Pan 292 may contain a nonadhesive PCM in an amorphous state. Additional details regarding the nonadhesive PCM are provided below. In order to maintain a desired viscosity of the nonadhesive PCM the pan 292 may be heated. While the tail 220 is being detected, the blade (or bar or wire) 280 of the blade-in-pan assembly (or bar or wire and pan assembly) 290 is submerged in the pan 292. After the tail of log 220 is detected, the blade 280 is raised out of the pan 292 carrying an amount of the nonadhesive PCM in an amorphous state and is timed so that the body 130 rolls over blade 280 after being ejected from the in-feed rolls 210. After the wound log 120 passes, the blade 280 is lowered back into the pan 292. The blade 280 height can be adjusted so that the top of the blade 280 is slightly higher than the adjacent table 240.
After application of the nonadhesive PCM, the wound log 120 rolls down the table 240 to the out-feed rolls 294 which compress the tail 220 to the body 130. The nonadhesive PCM, while in tis amorphous state, wicks through the fibers of each of the tail 220 and the body 130 to form mechanical bonds. In some embodiments, subsequent to applying the heated nonadhesive PCM material to the application site, heat can be removed from the applied nonadhesive PCM to expedite the phase change from an amorphous state to a non-amorphous (e.g., a solid state) to expedite the bonding process. In other embodiments, ambient temperature is sufficient to change the phase of the nonadhesive PCM material at a suitable rate.
The lower out-feed roll 296 runs slower than the upper out-feed roll 298, which moves the wound log 120 through the out-feed rolls 294 for a controlled duration, similar to the in-feed rolls 210. The lower out-feed roll 296 speed is controlled as a percentage of the upper out-feed roll 298 speed. More closely matching the upper out-feed roll 298 and lower out-feed roll 296 speeds will allow the out-feed rolls 294 to hold the wound log 120 longer.
When the wound log 120 is released from the out-feed rolls 294, it rolls down the table 240 to the next converting operation—typically an accumulator in-feed. A typical blade-in-pan style tail sealer 100 may operate at a rate of not less than about 20 logs processed/minute, or at rate of about 30 to about 60 logs processed/minute, or a rate of about 50 to about 60 logs processed/minute. As one of skill in the art will recognize, other arrangements of portions of the exemplary tail sealers 100 can be used. For instance, the relative speeds of the upper in-feed rolls 212 and lower in-feed rolls 214 may be changed, the table 240 placement as well as the presence of a log in-feed section, log index to sealing station, tail identifying, tail winding and log discharge portions may be modified. As a nonlimiting example, belts may be used in lieu of rolls. Likewise, the angles and distances of the blade 280 and/or the he pan 292 relative to the application site and/or table 240 may be altered as may the application pressure or velocity. Additionally, timers and/or other control features may be used to manage the rate of operation and/or prevent backlog or overfeeding of the logs 120 into the tail sealer 100.
Furthermore, while
Once cut into consumer-sized product units the convolutely wound log 120 having its tail 220 bonded with the nonadhesive PCM in accordance with the present disclosure may have a tail seal release ranging from about 50 g/11 inch roll to about 400 g/11 inch roll, or from about 80g/11 inch roll to about 300 g/11 inch roll, or from about 100 g/11 inch roll to about 200 g/11 inch roll as determined by the Tail Seal Release Strength Method described herein.
The wound log 120 may comprise a web material 250 that is a fibrous structure. The web material 250 may be provided as a single-ply or multi-ply sanitary tissue product, such as a paper towel product or a bath tissue product, for example. As shown in the cross-sectional view of an example web material 250 shown in
Generally, the peaks 252 and valleys 254 extend in opposite directions in Z-direction. In one nonlimiting example, a peak 252 extends upward in the Z-direction. The valley 254 in this case may extend downward in the Z-direction, away from the peak 252. In one embodiment, the peak 252 is located on the tail 220. In another embodiment, the peak 252 is located on the body 130 (i.e., the non-tail portion). Alternatively, the peaks 252 may be found on both the body 130 and the tail 220. Likewise, valleys 254 may be located on the tail 220, the body 130 or both the portions of the web material 250. The peaks 252 and/or valleys 254 may be found on one or multiple sides of the web material 250. Where multiple peaks 252 are found on the web material 250, said peaks 252 may comprise different heights, shapes and/or sizes. Likewise, where multiple valleys 254 are found on a web material 250, the valleys 254 may comprise different heights, shapes and/or sizes.
In one nonlimiting example, a peak 252 and valley 254 are adjacent and have a maximum height distance, H, of about 180 microns to about 1750 microns between them. In another nonlimiting example, the maximum height distance, H, is from about 365 microns to about 780 microns. The height distance is measured by measuring distance between the furthest points on the peak 252 and the valley 254 in the Z-direction. In one nonlimiting example, as shown in
In accordance with some embodiments, the bond strength between the tail 220 and the body 130 can be selectively reduced subsequent to forming the bond between the tail 220 and the body 130. For example, once the wound log 120 is cut into consumer sized widths and packaged, or at least ready for packaging, the nonadhesive PCM 406 may be in a generally solid state and mechanically entangled with the both the tail 220 and the body 130. It may not be necessary, however, to maintain a relatively high bond strength at this point in the manufacturing process. A strength degradation accelerator may be used to change the phase of the nonadhesive PCM 406 to the amorphous state. In one embodiment, heat is used as the strength degradation accelerator and the wound log 120 is passed through a heat tunnel or other type of oven. The particular amount of heat necessary to initiate the phase change may be based on, for example, the amount of nonadhesive PCM 406 present on the wound log 120. Additionally or alternatively, other strength degradation accelerators may be used, such as pressure changes, vibrations, and/or combinations thereof, for example. In one embodiment, the wound log 120 is individually heated. In other embodiments, heat is applied to a package of a plurality of consumer-sized widths of the wound log 120 that have been prepared for shipping or distribution. In any event, once in the amorphous state, the nonadhesive PCM 406 may wick through the webs of the tail 220 and the body 130, thereby reducing the relative bond strength. The nonadhesive PCM 406 can then be transitioned back to the solid state through a removal of heat, either by removing the heat source or using other cooling techniques. In view of this reduction of the bond strength, a consumer interacting with the product may be able to separate the tail from the body with relative ease due to the diminished bond strength.
Tail Seal Release Strength Method
Tail seal release strength of typical paper towel or tissue sample sealed in accordance with the apparatus and method described above can be evaluated using this method. Time of evaluation should be chosen to correlate with desired intervals of importance in the product's life-cycle (i.e. during processing, at consumer use, etc.)
A) Start timing from application to the wound log.
B) Collect the roll once it is in consumer-sized finished roll format.
C) Once desired time interval has elapsed after application, begin testing. Hold roll in a horizontal position with the tail disposed at the 3 o'clock position, where the tail is pointed upwards as shown in
D) While holding roll in position attach weighted clips having known weights to the center of the tail. Successive clips are attached to alternating sides of the preceding clip. Alternatively, a single weighted clip having a known weight can be used in combination with a set of known weights which can be added to the single clip either singly or in combination. (See
E) Once the tail fully releases from the roll, stop and remove clips and/or weights.
F) Sum up the masses of all the clips/weights that were attached to the roll at tail release. This total weight is the tail-release strength.
G) Enter the total weight in the summary sheet.
Also shown in graph 600 is a horizontal line 608 that represents the initial tail release strength of the nonadhesive PCM. It is noted that the tail release strength of Glue C (curve 606) does not reach the same tail release strength as initial tail release strength of the nonadhesive PCM, shown as intersection A, until approximately 480 minutes (8 hours) after the glue is applied to the log. The tail release strength of Glue D (curve 604) takes approximately 800 minutes (13+hours) to reach the same tail release strength as the initial tail release nonadhesive PCM, shown as intersection B.
As is to be appreciated, the tail release strength over time may differ based on the particular composition of the nonadhesive PCM that is used to bond the tail to the body. For example, some nonadhesive PCMs may offer higher or lower initial tail release strengths and then subsequently decline in strength and a greater or lesser rate that the curves 502, 602 depicted in
The differential scanning calorimetry data presented in
The dimensions and/or values disclosed herein are not to be understood as being strictly limited to the exact numerical dimension and/or values recited. Instead, unless otherwise specified, each such dimension and/or value is intended to mean both the recited dimension and/or value and a functionally equivalent range surrounding that dimension and/or value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”.
Every document cited herein, including any cross referenced or related patent or application is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
