Patent Application
20090292270
This invention relates to fastener tabs for disposable absorbent articles.
Disposable absorbent articles, such as diapers, training pants, incontinence garments, feminine hygiene garments, and the like typically include a self-fastening mechanism that allows the absorbent article to be fastened about the waist of a wearer. One type of self-fastening mechanism is a fastener tab. The fastener tab includes an installation portion that is fixed to an anchor region of the absorbent article (e.g., diaper chassis, including the back waist portion) and a fastening portion that is configured to be fastened to an attachment region of the absorbent article, which is sometimes executed as a landing zone, to hold the absorbent article in place about a wearer's waist. The installation portion may be permanently affixed to the anchor region. The fastening portion is configured to be capable of removal from a release surface (e.g., a release substrate surface) on which it is installed during the manufacture of the absorbent article. The fastening portion is then able to be attached to the attachment region.
It is desirable that the fastening portion be capable of being removed and refastened to the attachment region several times while still providing an acceptable strength of connection with the attachment region during use. Thus, a typical fastener tab must provide two different types of adhesion with respect to the absorbent article, a permanent connection via the installation portion and a removable and refastenable connection via the fastening portion. Often, the fastening portion includes a layer of some type of mechanical fastening means, such as, for example, hooks. Hooks require a mating element in the attachment region, which typically includes a separate fibrous layer of loops. The hook/loop systems, as well as other mechanical fastening systems, however, add avoidable costs and complexities to the manufacture of absorbent articles. As such, it is desirable to eliminate these costs in order to provide a low cost absorbent article, while retaining the refastenable connection between the fastener tab and the attachment region.
An alternative to using a mechanical fastening system would be to use a fastener tab consisting only of an adhesive. Such a system would not provide a cost advantage, however, in light of how typical fastener tabs are made. For instance, typical fastener tabs are made from a plastic substrate that includes a coating of a single type of adhesive that covers both the installation portion and the fastening portion. Because a single type of adhesive is used for both the installation and fastening portions, the adhesive is not singularly optimized for both the installation or fastening portions. As such, additional features are often added to the absorbent article to achieve the desired fastener tab functionality. For example, if an adhesive that allows for removal and refastening of the fastening portion is used, the installation portion may require additional measures, such as mechanical bonding, to provide a permanent bond with the absorbent article. If an adhesive that allows for a permanent bond of the installation portion is used, the fastening portion will not be refastenable without the use of special coating on the release surface and the attachment region. These measures add additional material and processing costs to the absorbent article. As such, it is desirable to eliminate these costs in order to provide a low cost absorbent article. Specifically, it is desirable to provide a fastener tab that is capable of being permanently connected to the anchor region of the absorbent article and refastenably connected to the attachment region of the absorbent article without resorting to the use of extra measures (e.g., mechanical bonding or release surface coatings).
In order to overcome the problems discussed above, it would be desirable to create a fastener tab consisting of a substrate with one or more adhesives that create a fastening portion having different adhesion characteristics than the installation portion, such that mechanical fasteners on the fastening portion and mechanical bonds securing the installation portion to the chassis are unnecessary. Because of the scale and equipment commonly used by the fastener tab suppliers, however, such would be cost prohibitive. As background, typically, fastener tabs are fabricated from large (e.g., 6-8 feet) rolls of tape substrate off site from the absorbent article lines. The rolls of tape substrate are made by applying a release agent to one side of a tape substrate and winding the tape substrate onto a roll. As the roll of tape substrate is unwound the other side of the substrate is coated with an adhesive (typically via a spray coater), forming a tape stock. The tape stock is then rewound into wide rolls and cut to customer specified widths prior to shipping. Finally, at the place of manufacture of the absorbent article, the tape is unwound, cut to length, and joined to the chassis of an absorbent article. The use of prefabricated fastener tabs adds material cost to the absorbent article because it requires the use of release agent on the side opposite the adhesive side of the tape substrate so that the tape substrate can be rolled up for shipment.
Creating the above-described desired fastener tabs having different adhesion characteristics would be cost prohibitive and impractical for a fastener tab supplier for multiple reasons. First, in order to continue to fabricate large tape stock rolls, the supplier would have to invest in a more precise adhesive applicator (e.g., transition from a spray coater to multiple slot coaters), which would be cost intensive. Second, highly precise cutting units would need to be used to cut the appropriate fastener tab roll sections from the larger tape stock roll, which would be cost intensive and executionally impractical (waste would be substantially higher in this process). Third, fastener tab suppliers can't switch over to making individual fastener tab rolls because it would require substantially the same time to fabricate a much smaller fastener tab roll as it does a large tape stock roll, or be more capital intensive to do so. Thus, production time and cost would increase. For all of these reasons it would be desirable to fabricate a fastener tab on-line, simultaneously with the absorbent articles themselves. Particularly, it would be desirable to avoid the need to use a release agent, and to have the flexibility to make slight adjustments to the adhesion characteristics of the fastener tab for a variety of reasons, including adjusting adhesion characteristics to 1) geographic climate variations where the absorbent article is made or where it will be used, 2) needs of the wearer, 3) size/surface area of the fastener tab, and 4) the needs of the care provider.
Made in accordance with an embodiment of the present invention, a fastener tab includes a tab substrate having a first side and a second side. A first adhesive region is applied to an installation portion of the first side and a second adhesive region is applied to a fastening portion of the first side. The first and second adhesive regions are configured to provide different adhesion characteristics.
Made in accordance with an embodiment of the present invention, a fastener tab includes a tape substrate having a first side and a second side. A first adhesive is applied to an installation portion of the first side to form a first adhesive region and a second adhesive is applied to a fastening portion of the first side to form a second adhesive region. The first and second adhesive regions are configured to provide different adhesion characteristics.
A fastener tab in accordance with an embodiment of the present invention may include a fastening portion, an installation portion, and a grip region disposed along an outer edge of the fastening portion that is substantially free of adhesive. The fastening portion has a first adhesive region and the installation portion has a second adhesive region. The fastening portion may have a lower peel force than the installation portion. The first adhesive region may include a first adhesive and the second adhesive region may include a second adhesive. The first adhesive and second adhesive may be applied according to different patterns, such as, for example, a continuous coating, stripes, or discrete regions. The adhesives in the first and second adhesive regions may be applied to a nonwoven layer of the tab substrate.
An absorbent article in accordance with an embodiment of the present invention includes a backsheet having an exterior surface and an interior surface. The exterior surface includes an anchor region and an attachment region. The absorbent article also includes at least one fastener tab. The fastener tab comprises a tab substrate having a first side and a second side, a first adhesive region applied to an installation portion of the first side and a second adhesive region applied to a fastening portion of the first side. The first and second adhesive regions are configured to provide different adhesion characteristics. The fastener tab is fixed to the anchor region with the first adhesive region and the second adhesive region is releasably connected to a release surface of a release substrate.
a-2c are cross section views of a fastener tab installed on an absorbent article in accordance with one or more embodiments of the present invention.
a-3d are plan views of fastener tabs constructed in accordance with various embodiments of the present invention.
a and 7b are schematic illustrations of a fastener tab constructed in accordance with one or more embodiments of the present invention being tested for dynamic shear strength according to a described test method.
a and 8b are schematic illustrations of a fastener tab constructed in accordance with one or more embodiments of the present invention being tested for shear hang time according to a described test method.
With reference to
In
When the absorbent article 20 is fastened to a wearer, the fastening portion 143 of the fastener tab 40 is deployed from the release surface 45 as shown in
While an absorbent article 20 will be referenced in this description, it will be apparent to one of skill in the art that the fastener tab 40 described herein may be advantageously employed in connection with any number of absorbent articles 20 that utilize fastener tabs 40. Other exemplary absorbent articles that may be used with the fastener tabs 40 of the present invention include U.S. Pub. Nos. 2005/0171499, 2005/0203475, 2005/0288645, 2005/0288646, 2006/0264860, 2006/0264861, 2006/0271005, 2006/0293637, and 2006/0293638.
a is a cross section view of the fastener tab 40 folded over as installed or fixed on an ear flap 30 at the time of manufacture.
Many tab substrates 140 are known, many of which are laminates of various films and/or nonwovens and include at least one side that is a plastic film on which adhesive is applied. Tab substrates 140 are typically constructed to have a tensile strength of more than about 18 Newtons per centimeter (“N/cm”) and have a thickness of at least 50 microns. Nonwovens are often selected for an external layer of the tab substrate 140 because they present a soft, cloth-like texture. However, because nonwovens have holes or interstitial spaces between their fibers through which adhesive is prone to migrate, the tab substrate 140 includes a plastic film layer (not shown) on which adhesive (e.g., a first adhesive 70 and second 72) is applied. To construct such a laminated tab substrate 140, the nonwoven is typically glued to a plastic film layer and the plastic film layer is then coated with adhesive.
One exemplary tab substrate (not shown) includes two nonwoven, spun-bond fiber layers on either side of a melt-blown layer (not shown). In this embodiment, the various adhesives may be applied directly to a nonwoven tab substrate instead of a plastic film. The nonwoven to which the adhesive is applied has an air permeability of less than about 12 m3/m2/min. It is believed that an air permeability in this range provides sufficient resistance against adhesive migration.
As may best be seen in
The release surface 45 may be formed by, for example, a release substrate 151 that is adhered to an interior surface 74 of the ear flap 30 with release substrate adhesive 153. One exemplary release substrate 151 is an 80 micron thick plastic film coated with a release substrate adhesive 153 such as, for example, Bostik 2861. In the embodiment shown in
The difference in adhesion characteristics between the first adhesive region 157 on the installation portion 141 and the second adhesive region 159 on the fastening portion 143 may be achieved in any number of ways. For example, the fastener tab 40 shown in
The fastener tabs 40 shown in
In other embodiments the second adhesive region 159 on the fastening portion 143 is configured to fix some other fastening mechanism, for example, a mechanical fastening mechanism, such as a patch of hooked material that is configured to engage a fibrous layer of loops in the attachment region (not shown), to the fastener tab.
The various adhesion characteristics of a bond between an adhesive region (e.g. first adhesive region 157 and the second adhesive region 159) and the absorbent article 20 (e.g., the anchor region 53 and the attachment region 55) can be quantified in many ways. Three commonly measured qualities of the bond are, for example, T-Peel strength, dynamic shear, and shear hang time. These qualities can be measured by many different methods that are recognized in industry. For informational purposes, an exemplary method for measuring T-Peel strength, dynamic shear, and shear hang time are provided below.
For each of the sample preparations described below, the fastener tab 40, the anchoring region 53, and the attachment region 55 must be handled with care to avoid contact with hands, skin, or other contaminating surfaces. Clean sheets of untreated paper may be used to protect the surfaces of the fastening surfaces during the sample preparation.
Referring now to
Sample Preparation—The sample preparation for T-peel test will vary based on whether the fastener tab 40 and specifically the fastening portion 143 is available as a discrete web or is incorporated in a product. T-Peel forces referenced herein are in the context of the fastening portion 143 being tested after being bonding to the attachment region 55.
A skilled artisan should recognize that bonded specimens of other dimensions may be used in the T-Peel Method. The dimensions of the receiving and engaging members may vary from those listed above; however, the effective bonding area should be used to normalize the resultant T-Peel force recorded per inch of bonded width (i.e., the bonded width being the width of the bonded area measured substantially parallel to the grip width once the sample is mounted in the tensile tester).
Materials incorporated in a product: To perform the T-peel test, the fastener tab 40 material is cut from the product so as to isolate the fastening portion 143 and the attachment region 55, if possible. Removal of the materials from the product should be done to preserve the integrity of the materials (e.g., fastener tab 40, especially the fastening portion 143, and the attachment region 55 should not be permanently deformed or should not be debonded from each other). Before loading the samples for T-peel test, the fastening portion 143 and attachment region 55 should be separated approximately 1-5 mm to initiate the peeling if a grip portion 145 is not available. The front waist 32 portion of the sample including the attachment region 55 is the receiving sample, and the fastener tab 40 of the sample including the fastening portion 143 is the engaging sample. The receiving sample and engaging sample should each extend at least 5 millimeters beyond the bonded portion of the samples such that the proximal edge of the receiving sample and the proximal edge of the engaging sample can be easily placed in the test instrument's grips. If needed, an additional length of 2 mil PET film (not shown) may be attached to the proximal edges of the front waist 32 and the grip portion 145 using double sided tape. The T-peel test should be performed on the bonded materials as described in the method below. A skilled artisan should recognize that peel angle can affect the peel force. During peeling, the peel angle should be maintained around 90 degrees. Furthermore, if the fastening portion 143 or attachment region 55 are elastomeric, the fastening portion 143 or attachment region 55 must be backed with a similar sized sheet of 2 mil (0.05 mm) PET film (not shown) in order to prevent stretching of the tested substrate.
If the product is not pre-engaged, the materials are cut from the product and sample preparation would be similar to the method presented above for a sample in a film form. The average load calculated in peel force test should be normalized by the width of the fastener (in inches).
Refastened samples—Any of the above mentioned bonded samples may be refastened. The bonded sample is debonded using the tensile tester and following the Test Conditions for the T-Peel Test as provided for below (e.g., crosshead speed of 12 inches/minute). The fastening portion 143 and attachment region 55 are refastened in a configuration substantially similar to the configuration in which they were originally attached while avoiding wrinkles with only exception being that a fresh surface of the attachment region 55 is used. The refastened sample is rolled with a 4.5 pound (2 kg) HR-100 ASTM 80 shore rubber-faced roller. Two full strokes (i.e., back and forth) are applied to the sample at a speed of approximately 10 mm/sec (i.e., rolling should take approximately 40 seconds. After 1 minute of dwell time, the T-Peel Test is performed. This is the first refastened T-Peel force. This procedure may be repeated as needed to yield sequential refastened T-Peel forces (i.e., a second refastened T-Peel force, a third refastened T-Peel force, etc.).
Test Conditions—The T-Peel test method is performed in a controlled room at 22° C.+/−2° C. and RH 50% +/−10%. Suitable instruments for this test include tensile testers commercially available from Instron Engineering Corp., Canton, Mass. (e.g. Instron 5564) or from MTS Systems Corp., Eden Prairie, Minn. (e.g. Alliance RT/1 or Sintech 1/S). The following procedure illustrates the measurement when using the Instron 5564. The instrument is interfaced with a computer loaded with the Instron® Merlin™ Material Testing Software which controls the testing parameters, performs data acquisition and calculation, and provides graphs and data reports. The instrument is configured with a data acquisition speed of 50 Hz. Any resulting graphs are plotted using the Average Value (integral) setting on the instrument. A load cell is selected so that the forces to be measured will be between 10% and 90% of the capacity of the load cell or the load range used (e.g., typically, a 10 N to 100 N load cell). The instrument is calibrated to an accuracy of at least 1% and, ideally, less than 0.1% according to the manufacturer's instructions. The instrument has two grips: a stationary grip 850 and a movable grip 852. The grips 850, 852 used are wider than the sample; typically, 2 inch (5.08 cm) wide grips are used. The grips 850, 852 are air-actuated grips and are designed to concentrate the entire gripping force along a plane perpendicular to the direction of testing stress. The distance between the lines of the gripping force (i.e., gauge length) is set to 1″ (2.54 cm). The load reading on the instrument is zeroed to account for the mass of the fixture and grips. The bonded sample is mounted into the grips. The bonded sample is mounted so that the proximal edge of the receiving sample is in the movable grip and the proximal edge of the engaging sample is in the stationary grip. The bonded sample is mounted such that there is a minimum amount of slack in the receiving sample or engaging sample between the grips. The load cell is zeroed.
The receiving sample is separated from the engaging sample using a crosshead speed of 12 inches/min (305 mm/min). An average load is calculated as the average load between about 1″ (about 25 mm) and about 3.5″ (about 88 mm) displacement. For samples that do not meet the dimensions provided in the Sample Preparation, the average load is calculated from the loads acquired from the crosshead extension between about 25% to about 87.5% of the sample length. For example, if the sample is 6 inches long, the average load is calculated between about 1.5 inches and about 5.24 inches of crosshead extension. The average load is normalized to a width of 1″ (2.54 cm) as follows: normalized load=average load÷initial bond width in inches.
a and 7b show a fastener tab 40 installed in clamps 950 and 952 for dynamic shear testing. This method is used to determine the shear strength of the bond formed between the fastener tab 40, specifically the installation portion 141, to the anchor region 53 and the fastener tab 40, specifically the fastening portion 143, to the attachment region 55. Additionally this method is used to determine the shear strength of the bond formed between the fastener tab 40, specifically the fastening portion 143, after refastening such that a bond has been broken and subsequently a new bond created with the fastening portion 143 and a fresh section of the attachment region 55.
Sample Preparation—The sample preparation for Dynamic Shear test will vary based on whether the material is available as a discrete web or is incorporated in a product. Dynamic shear forces referenced herein are in the context of the fastening portion being tested after being bonded to the attachment region.
To perform the dynamic shear test, the material is cut from the product so as to isolate the anchor region 53 or the attachment region 55 and the installation portion 141 or the fastening portion 143 respectively, if possible. Removal of the materials from the product should be done to preserve the integrity of the materials (e.g., anchor region 53 and installation portion 141 should not be permanently deformed or debonded). The anchoring region 53 is attached to a 2″×6″ stainless steel plate 928 to form an engaging sample. The installation portion 141 should have a distal edge that extends at least 5 millimeters from the bonded portion of the fastener tab 40 and anchor region 53 such that the distal edge can be easily inserted into the test instrument's grips. If needed, an additional length of 2 mil PET film (not shown) may be attached to the distal edge of the fastener tab 40 using double sided tape. The Dynamic Shear test should be performed on the bonded materials as described in the method below.
If the product is not pre-engaged, the materials are cut from the product and sample preparation would be similar to the method presented above for a sample in a film form.
The sample is rolled with a 4.5 pound (2 kg) HR-100 ASTM 80 shore rubber-faced roller. Two full strokes (i.e., back and forth) are applied to the sample at a speed of approximately 10 mm/sec. The resulting sample, called a bonded sample 910, is allowed to sit for 1 minute of dwell time.
Test Conditions—The Dynamic Shear test method is performed in a controlled room at 22° C. +/−2° C. and RH 50% +/−10%. The tensile tester is the same as used in the T-Peel test. A load cell is selected so that the forces to be measured will be between 10% and 90% of the capacity of the load cell or the load range used (e.g., typically, a 100 N to 250 N load cell). The instrument is calibrated to an accuracy of at least 1% and, ideally, less than 0.1% according to the manufacturer's instructions. The tensile tester has two grips: a stationary grip 950 and a movable grip 952. The grips are wider than the fastener tab 40 or anchor region 53 (e.g., typically, about 1 to about 2 inch wide (2.54-5.08 cm)). The grips 950, 952 are air-actuated grips and designed to concentrate the entire gripping force along a plane perpendicular to the direction of testing stress. Referring to
The anchoring region 53 is separated from the installation portion 141 using a crosshead speed of 12 inches/min (305 mm/min) until the two samples are completely disengaged or one of the bonded samples 910 fails (e.g., the anchor region 53 tears, the fastener tab 40 tears, or the sample debonds at an interface other than of that between the anchoring region 53 and the installation portion 141).
If the bonded sample fails at any location other than the interface between the anchoring region 53 and the installation portion 141 prior to reaching a maximum load of at least 20 N/in2, the data is to be discarded and another sample must be run using a backing material to prevent the sample form tearing and/or using a stronger double sided tape.
The Maximum Load is recorded and normalized to Newtons per inch2 as follows: normalized load=measured load÷bonded area in inches squared.
a and 8b illustrate a sample fastener tab 40 installed on backing surface (e.g. an attachment region 55 in
Sample Preparation—The sample preparation for Shear Hang Time test will vary based on whether the material is available as a discrete web or is incorporated in a product. Tape shear hang time results referenced herein are in the context of the installation portion being incorporated in the product at the anchor region.
For a fastener tab 40 having a fastening portion 143 or a installation portion 141, an attachment region 55 or anchor region 53 respectively is resized using cutting dies to create a rectangular sample with the dimensions of about 3.5 cm×about 7.5 cm (1.4″×3.0″). The adherend being either an attachment region 55 or anchor region 53 is backed with a like sized backing sheet of (polyethylene terephthalate) film or paper (not shown). The backing sheet must be positioned and sized so as to not interfere with the interface of the fastening portion 143 or installation portion 141 to the attachment region 55 or anchor region 53 respectively.
For the attachment region 55 or anchor region 53, an approximately 1.3 cm×2.54 cm (0.5″×1″) piece of an attachment region 55 or anchor region 53 is bonded in a face-to-face relationship to a similarly sized piece of double-sided tape 1026 (such as FT 239 available from Avery Denninson Corp., Painesville, Ohio or 9589 available from 3M, St. Paul, Minn.). The fastening portion 143 or installation portion 141 is to be wrinkle free. It should be appreciated that the fastening portion 143 or installation portion 141/double sided tape 1026 laminate can be created with larger sized materials and then resized to 1.3 cm×2.54 cm. The other side of the double side tape 1026 is bonded to a test panel 1028 having a proximal edge 1042 and a distal edge 1046. The double side tape 1026 is bonded adjacent the proximal edge 1042 of the test panel 1028. The test panel 1028 is ideally made from steel (ASTM A666 specification); alternately, the test panel 1028 may be made from a corrugated cardboard with a thickness of at least about 3-4 mm. The attachment region 55 or anchor region 53 is bonded onto the fastening portion 143 or installation portion 141 respectively. The bonded sample 1010 is then rolled with a 4.5 pound (2 kg) HR-100 ASTM 80 shore rubber-faced roller. Two full strokes (i.e., back and forth) are applied to the sample 1010 at a speed of approximately 5 mm/sec. The bonded area should be approximately 2.54 cm×1.3 cm (0.5″×1.0″).
A skilled artisan should recognize that bonded specimens of other dimensions may be used in the Shear Hang Time Test Method. The dimensions of the receiving and engaging members may vary from those listed above. However, if the bonded area exceeds approximately 2.54 cm×1.3 cm (0.5″×1.0″), the sample should be resized to yield a bonded area of 2.54 cm×1.3 cm (0.5″×1.0″).
Materials incorporated in a product: To perform the tape shear hang time test, the material is cut from the product so as to isolate the attachment region 55 or anchor region 53 and the fastening portion 143 or installation portion 141 respectively, if possible. However, if the attachment region 55 or anchor region 53 and/or the fastening portion 143 or installation portion 141 respectively are joined to other materials in a face-to-face configuration, the face-to-face configuration between the attachment region 55 or anchor region 53 and the other material or the fastening portion 143 or installation portion 141 respectively and the other material should be maintained. Removal of the materials from the product should be done to preserve the integrity of the materials (e.g., the attachment region 55 or anchor region 53 and the fastening portion 143 or installation portion 141 respectively should not be permanently deformed and should not be debonded from each other). The fastening portion 143 or installation portion 141 should have a distal edge 1044 that extends at least 50 millimeters from the bonded portion of the attachment region 55 or anchor region 53 and the fastening portion 143 or installation portion 141 respectively such that the distal edge can be easily be folded over to form a loop 1062. If the distal edge does not extend at least 50 mm, an additional length of 2 mil PET film (not shown) may be attached to the distal edge 1044 using double sided tape. The shear hang test should be performed on the bonded materials as described in the method below.
If the product is not pre-engaged, the materials are cut from the product and sample preparation would be similar to the method presented above for a sample in a film form.
When determining the tape shear hang time of the fastening portion 143 to the attachment region 55 the bonded sample is rolled with a 4.5 pound (2 kg) HR-100 ASTM 80 shore rubber-faced roller. Two full strokes (i.e., back and forth) are applied to the sample at a speed of approximately 5 mm/sec. The sample is allowed to sit for 1 minute of dwell time.
Test Conditions—The bonded sample 1010 is prepared at ambient room conditions (e.g., 22° C.+/−2° C. and RH 50% +/−10%). The bonded sample 1010 is brought into a temperature chamber immediately prior to the commencement of testing. The time between introduction of the bonded sample 1010 into the temperature chamber and commencement of testing is to be less than 5 minutes. The test is conducted in a 100° F. controlled temperature chamber or oven (37.5° C. +/−2° C.). Suitable instruments for this test are the RT10 or RT30 available from ChemInstruments Inc, Fairfield, Ohio or any apparatus having a rack or jig capable of holding a test plate within 0° to 2° of vertical. The time is measured by an automated timer capable of reading to the nearest minute.
a and 8b are cross-sectional views of the bonded sample 1010 in a test apparatus. The distal edge 1044 of the fastening portion 143 or installation portion 141 is folded onto itself and affixed with a staple 1060 to form a loop 1062. The distal edge 1046 of the attachment region 55 or anchor region 53 is placed into a rack 1068 so that the fastening portion 143 or installation portion 141 hangs downwards. The 1 kg weight 1064 is attached to the looped end of the fastening portion 143 or installation portion 141. The timer is started once the weight 1064 hangs freely from the fastening portion 143 or installation portion 141. The time required for debonding of the fastening portion 143 or installation portion 141 and the attachment region 55 or anchor region 53 is recorded (i.e., the fastening portion 143 or installation portion 141 separates and falls from the attachment region 55 or anchor region 53). The test can be manually stopped if the sample remains bonded beyond a prescribed time period.
If the bonded sample fails at a time less than specified with this disclosure for some reason other than separation of the interface between the fastening portion 143 or installation portion 141 with the attachment region 55 or anchor region 53 respectively (e.g., the fastening portion 143 or installation portion 141 tears, attachment region 55 or anchor region 53 tears, or the sample debonds at an interface other than of that between the fastening portion 143 or installation portion 141 and the attachment region 55 or anchor region 53 respectively, the data is discarded and another sample must be run using a backing material to prevent the sample from tearing and/or using a stronger double sided tape to prevent separation at interfaces other than between the fastening portion 143 or installation portion 141 and the attachment region 55 or anchor region 53 respectively.
Turning now to
To achieve the striped pattern shown in the second adhesive region 159′, a shim 211 is placed on the slot coater 210 that blocks a portion of the nozzles 177. The shim 211 includes a central opening 183 corresponding roughly to the size and shape of the first nozzle 175. The shim also includes holes 178 that are aligned in front of the nozzles 177 and through which the second adhesive 72 flows to create the striped pattern of adhesive. The use of the shim 211 on the slot coater 210 enables the specific pattern of adhesive to be varied by a simple change of shims. It will be apparent to one of skill in the art that other patterns of adhesive (e.g., the first and second adhesives 70 and 72) can be achieved in the first or second adhesive regions 157 and 159 by varying the size, shape, or configuration of the shim 211, as well as the flow of adhesive through the first and second nozzles 175 and 177.
The grip region 145 can be seen on either side edge 80 and 82 of the processed tab substrate 140. If the grip region 145 is not desired, the second nozzles 177 may direct the flow of adhesive to the side edges 80 and 82 of the tab substrate 140.
The substrate 140 shown in
While any number of substrates, laminates, films, and adhesives can be used in the practice of the present invention, the following materials are considered to be suitable examples. The fastener tab substrate 140 may be unglued Avery fastening tape (3-4 mil polypropylene), unglued Clopay tape (3-4 mil polyethylene), unglued Clopay tape (2-3 mil) laminated to 10 gsm nonwoven substrate, 78 gsm nonwoven (SMS and SMMS) from PGI, or a lamination of 66 gsm nonwoven (RKW)/50 gsm spunbond nonwoven (RKW)/cPP Plastic (80 micron) (Novel). The release substrate 151 may be unglued Avery release substrate (3-4 mil polypropylene), unglued Clopay tape (2 mil) silicone coated), or cPP plastic film (50 or 80 micron)(Novel). Adhesives that can be used as substrate adhesive 153 or in the first or second adhesive regions 157 and 159 can be Avery, hot melt, Fuller 1358LO, Bostik 2861, NSC 526, or NSC 395c.
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that 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.
This application claims the benefit of U.S. Provisional Application Nos. 61/055,853 and 61/055,860, each filed on May 23, 2008, the substances of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61055853 | May 2008 | US | |
| 61055860 | May 2008 | US |
