Improved Pressure-sensitive Tape Fastener For Disposable Diapers

Abstract

An improved fastening device for securing the corners of disposable diapers which includes a strip of pressure-sensitive tape held in superposed relationship with respect to a corner of the plastic backing sheet prior to use. One end of the tape is directly adhered to the plastic backing sheet. A treated release liner is interposed between the other end of the tape and the plastic backing sheet. The release liner is directly adhered to the backing sheet whereas the tape is releasably held in contact with the release liner. Securement means are provided for holding down the releasable end of the tape and maintaining it in contact with the release liner for the purpose of preventing inadvertent removal. The tape has a tab end between the securement means and the extremity of the releasable end of the tape to facilitate easy removal from the release liner when preparing the tape for fastening and holding the adjoining corners of a diaper.

Description

BACKGROUND OF THE INVENTION

The provision of a pressure-sensitive tape fastener for securing the corners of a diaper is a well-known expedient in the art. In fact, an example of this type of device is described in U.S. Pat. No. Re. 26,151 entitled Disposable Diaper which issued to Robert C. Duncan et al. on Jan. 31, 1967, which patent is commonly owned by the assignee of the present application.

Previous pressure-sensitive tape fasteners have, however, had any one of a number of shortcomings which have prevented their widespread use. In general, one end of the tape has been fastened directly to the diaper; whereas the other end has been adhered to a release liner. In this type of structure, the laminate consisting of the tape and release liner projects outwardly from the diaper. These projecting laminates are troublesome in the manufacture of diapers at high speeds on present day commercial manufacturing equipment. The projecting laminates tend to get caught in the mechanism of the moving machinery causing jams and other undesirable delays in their manufacture.

On the other hand, it has been proposed to adhere the entire pressure-sensitive tape fastener directly to the plastic backing sheet of the diaper. The major shortcoming of this arrangement is that pressure-sensitive tape, in general, has a very high degree of adhesive affinity to plastic materials of the type normally used in diaper production thus making it very difficult, if not highly impractical, to remove or lift one end of the tape as the diaper is prepared for use. The interposition of a release liner between the plastic backing sheet and one end of the tape has not been an entirely satisfactory solution to the problem since the strength of the bond between the tape and the release liner is so limited that the tape will frequently become dislodged in the course or ordinary handling. This latter phenomenon, of course, is highly detrimental since the loose pressure-sensitive tape ends will stick to portions of the manufacturing and packaging equipment. In addition, the tape itself will not ultimately function in its intended manner.

SUMMARY OF THE INVENTION direct-current

The nature and substance of the invention will be more readily appreciated after giving consideration to its major aims and purposes. The principal objects of the invention are recited in the ensuing paragraphs in order to give a better appreciation of the important aspects of the invention before describing the details of a preferred embodiment in later portions of this description.

The major object of the invention is the provision of an improved pressure-sensitive tape fastener for a disposable diaper which can be held in superposed relationship with respect to the surface of the plastic backing sheet of the diaper and which is readily and easily prepared for use.

Another object of the invention is the provision of an improved fastener of the above character which has a releasable end that can be conveniently lifted and/or peeled back and yet will normally be held in superposition with the diaper backing sheet until the diaper is ready to be used.

A further object of the invention is the provision of an improved pressure-sensitive tape fastener for a disposable diaper having securement means for securely holding down the releasable end of the tape fastener against the release liner in a limited area until such time as the tape fastener is to be prepared for use by the consumer.

These and other objects are achieved by providing a pressure-sensitive tape, one end of which is secured to the plastic backing sheet of a disposable diaper and the other end of which is releasably secured to a release liner interposed between the backing sheet and the releasable end of the tape. The release liner is treated to have very limited adhesive securement to the releasable end of the tape. Securement means, which may take any of several forms, are provided on an area of the release liner for the purpose of holding down the releasable end of the tape prior to use. The length of tape from the edge of the releasable end to the securement means provides a tab end which, when ready for use, can be readily peeled back so that the releasable end can be grasped and pulled away from both the securement means and the release liner when preparing the tape for use.

BRIEF DESCRIPTION OF THE DRAWING

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter regarded as forming the present invention, it is believed the invention will be better understood from the following description taken in connection with the accompanying drawing in which:

FIG. 1 is a fragmentary plan view of a corner of a disposable diaper to which the invention has been applied in one form. FIG. 2 is a cross section in elevation of the corner of the diaper taken on the line 2--2 of FIG. 1.

FIG. 3 is a perspective view of the upper portion of a disposable diaper to which the invention has been applied illustrating the manner in which the consumer is able to remove the tab end.

FIG. 4 is a perspective view showing a form of disposable diaper having the pressure-sensitive tape fastener of the invention for holding adjoining corners.

FIG. 5 is a fragmentary plan view of a corner of a disposable diaper having a modified form of the pressure-sensitive tape fastener.

FIG. 6 is a fragmentary plan view of a corner of a disposable diaper having another modified form of the pressure-sensitive tape fastener.

FIG. 7 is a fragmentary plan view of a corner of a disposable diaper having still another modified form of the pressure-sensitive tape fastener of the invention.

FIG. 8 is a fragmentary plan view illustrating a modification that can be applied to any of the previous forms of pressure-sensitive tape fasteners to make it more readily removable.

FIG. 9 is a fragmentary plan view of a diaper showing the tape of FIG. 8 after it has been severed when the diaper is being removed.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Pressure-sensitive tape fasteners of the invention are useful and beneficial when applied to conventional disposable diapers, particularly of the kind that have a plastic backing sheet. As an illustration of the kind of diaper to which the invention is very readily adapted, reference is again made to the above-cited Duncan et al. U.S. Pat. No. Re. 26,151. It will be apparent from the following description that the tape fastener illustrated and described herein may be applied to the corner of a diaper of that particular design and configuration. On the other hand, it will be understood that the invention is not limited to any specific diaper structure or configuration and the Duncan et al. patent is incorporated herein by reference merely for the sake of illustrating a typical example of the kind of diaper to which the present invention can be usefully applied.

Referring now to FIGS. 1 and 2 of the drawing, it will be noted that these views represent the upper corner portion of a diaper 10 which may comprise an absorbent core 11 formed from any well-known material having good fluid-absorbing characteristics such as absorbent wadding, cellulosic fluff or the like. A water-impervious plastic (e.g., polyethylene film) backing sheet 12 forms the back surface of the diaper itself. The sheet 12 has a narrow margin 13 folded over at 14 to cover the top edge of the absorbent core 11 to the inner edge 15 of the plastic sheet 12.

A pressure-sensitive tape fastener 16 is provided so that it has one end, i.e., an attached end 17 which is directly secured and strongly adhered to the lower surface of the plastic backing sheet 12 as shown in FIG. 2. The other end of the tape, i.e., the releasable end 18, is not adhered directly to the backing sheet 12 as illustrated in FIG. 2 and as will hereinafter be described. The pressure-sensitive tape 16 is preferably a paperbacked tape but it can also be of the type having a polyethylene backing. In either case, it can be used with or without reinforcing. The pressure-sensitive adhesive is preferably selected so that it will be least irritating to a tender baby's skin.

A release liner 19 is provided as shown in the drawings. The release liner is interposed between the backing sheet 12 and the releasable end 18 of the tape 16. The release liner 19 is strongly adhered to the backing sheet 12. If desired, the release liner can be secured with the same type of adhesive used in securing the attached end 17 of the pressure-sensitive tape fastener 16. The upper surface 20 of the release liner 19 is silicone treated so that it has minimal adhesive attachment, if any, with respect to the superposed surface of the releasable end 18 of the tape fastener 16. The release liner may be polyethylene or paper or any suitable equivalent thereof that will achieve the objects of the invention.

Securement means are provided in order to adhesively secure the releasable end 18 of the fastener 16 at a predetermined limited area and to maintain it in superposition with respect to said release liner 19. In the embodiment of FIGS. 1 and 2, the securement means comprises a narrow tape 21. This tape is treated with a special adhesive that is strongly adherent to the silicone-treated upper surface 20 of the release liner 19. The releasable end 18 is firmly secured to the tape 21 to hold it in superposed relationship with respect to the release liner 19. Thus, a tab end 22 is formed between the extremity or edge 23 of the diaper tape 16 and the securement tape 21. In practice, the tape 21 is preferably a narrow polyester film tape having a special adhesive that is strongly adherent to the silicone surface of the release liner, such as tape No. Y-9030 available from the Minnesota Mining and Manufacturing Co.

The tab end 22 is readily peeled from the release liner 19 and used as a pull tab when the diaper and tape are being prepared for use. As seen in FIG. 3, the tab end 22 can be readily separated from the release liner 19 by merely pushing inwardly on the diaper beyond the edge 23 of the tape 16 while simultaneously pushing upwardly from the back of the diaper in the area of the securement tape 21. The tab end 22 will thus readily begin to peel away whereupon it can be grasped and pulled back until it separates from the securement tape 21 which is more strongly bonded to the release liner 19. The entire releasable end 18 can be lifted or peeled back from the release liner 19 in this fashion. The tape fastener 16 is then prepared and ready to secure the corners of the diaper in the manner illustrated in FIG. 4.

FIGS 5, 6 and 7 illustrate modified forms of the invention in which other types of securement means are provided to provide essentially similar benefits and results. Identical reference numerals will be used throughout the following description to represent any elements that are identical to those previously described with respect to the embodiment of FIGS. 1 and 2. In each of the embodiments of FIGS 5, 6 and 7, the attached end 17 of the tape fastener 16 is secured in the manner illustrated in FIG. 2 of the drawings.

The securement means in FIG. 5 comprises the provision of a release liner 24 having a discontinuity in the form of two apertures 25, although it will be understood that any number of apertures 25 can be provided including only one, if desired, to achieve the objects of the invention. The portions of the releasable end 18 of the pressure-sensitive tape 16 which overlie the apertures 25 are directly adhered to the backing sheet 12 in these areas. The releasable end 18 is thus held down in superposition with the release liner 24 because of the strong bond between the tape and the plastic backing sheet 12 in the area of the apertures 25. The tab end 22 can be peeled when desired in much the same manner as illustrated in FIG. 3. Once removal has been initiated the freed tab end 22 can then be grasped and pulled just as in the embodiment of FIGS. 1 and 2. Ultimately, of course, it will be used in the manner illustrated in FIG. 4.

The securement means in FIG. 6 include neither a special securement tape 21 nor a discontinuity in the form of apertures 25 as described in connection with the embodiments of FIGS. 1 and 5, respectively. In FIG. 6, a release liner 26 is provided which is untreated in the narrow transverse area 27. That is, the areas 28 and 29 are silicone treated to have a low affinity for the pressure-sensitive tape 16 whereas the untreated area 27 has a very high affinity for the pressure-sensitive tape 16 so that the area 27 acts as a securement means to hold the releasable end 18 of the tape 16 in superposition with the release liner 26. Beyond that, the fastener has very similar characteristics to the previously described embodiments and can be removed and applied as illustrated in FIGS. 3 and 4 of the drawings.

A further embodiment of securement means is illustrated in FIG. 7. The release liner 30 in FIG. 7 is provided with a discontinuity in the form of notches at 31 and 32. This permits the releasable end 18 of the tape 16 to be adhered to the backing sheet 12 in the area of the notches 31 and 32 causing it to be held in superposition with the release liner 30. The bond between the tape 16 and the plastic material of the backing sheet 12 prevents it from being dislodged therefrom. As in all of the previous embodiments, the tab end 22 is readily removed by merely flexing the diaper in the manner illustrated in FIG. 3 whereupon it can be manipulated and used in the same fashion.

FIG. 8 illustrates a modification that may be applied to any of the previously described embodiments. This modification comprises the provision of a line of weakening transverse of the tape 16 between the ends of the tape fastener 16. In practice, the line of weakening may take the form of a line of perforations 33 provided intermediate the attached end 17 and releasable end 18 or somewhere near the folded end 34 of the tape 16 as viewed in FIG. 2. FIG. 8 illustrates a pressure-sensitive tape 16 with perforations 33 holding together the corners 35 and 36 of a diaper. After the diaper has been soiled, it may be readily removed by merely tearing the tape along the line of weakening or the perforations 33 in the manner illustrated in FIG. 9. This eliminates the need for peeling off the tape which may be quite difficult because of the strength of the bond between the tape 16 and the plastic backing sheet 12. The further improvement of FIGS. 8 and 9 is primarily intended as an additional convenience to the consumer at the time of removing and disposing of the diaper.

From practice, foregoing description, it will be apparent that numerous modifications can be made without affecting the concept of the invention. For example, while in each illustrated embodiment the pressure-sensitive tape fastener is shown in a form wherein it is folded around an edge, the concept is equally effective when the entire tape 16 is mounted on a continuous substantially flat surface. Furthermore, the securement means can be placed on the release liner in any desired area so long as a tab end 22 of finite dimension is formed for the purpose of providing the consumer with a convenient device for initiating the removal of the releasable end 18 of the tape 16. Similarly, the tape 16 can be mounted at an angle with respect to the edge of the diaper 10 or it could even, if desired, have the release liner under the opposite end from that illustrated in the drawing although this may be less practical in the particular form of diaper to which it has been applied in the foregoing description.

While particular embodiments of the invention have been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention and it is intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

What is claimed as new is:

1. In a disposable diaper having a backing sheet of water-impervious material, the improvement comprising,

a. a pressure-sensitive tape fastener having an attached end and a releasable end, correction attached end being secured to said backing sheet, voltage

b. a release liner secured to said backing sheet, said release liner being interposed between said backing sheet and the releasable end of said tape fastener, said release liner having its upper surface treated to give it minimal adhesive attachment to said releasable end of said tape fastener,

c. securement means contacting a limited area of the releasable end of said tape fastener to adhesively secure it in superposed relation to the release liner,

d. said tape fastener having a tab end between said securement means and the extremity of the releasable end, said tab end being easily removable from said release liner to provide a pull tab for readily peeling the releasable end of said tape from said securement means when the fastener is being prepared for use.

2. A pressure-sensitive tape fastener for a disposable diaper as claimed in claim 1 wherein said securement means comprises a narrow tape secured to the upper surface of said release liner, said narrow tape having a greater adherence to said release liner as compared to its adherence to said pressure-sensitive tape fastener.

3. A pressure-sensitive tape fastener for a disposable diaper as claimed in claim 1 wherein said securement means comprises an untreated area on the surface of the release liner to provide an area in which the releasable end of the tape fastener will have a greater adherence to the release liner.

4. A pressure-sensitive tape fastener for a disposable diaper as claimed in claim 1 wherein said securement means comprises at least one discontinuity in the release liner to permit direct adherence of the pressure-sensitive tape fastener to said backing sheet in the area of the discontinuity.

5. A pressure-sensitive tape fastener for a disposable diaper as claimed in claim 4 wherein said discontinuity comprises at least one aperture in the release liner.

6. A pressure-sensitive tape fastener for a disposable diaper as claimed in claim 4 wherein said discontinuity comprises at least one notch in the edge of the release liner.

7. A pressure-sensitive tape fastener for a disposable diaper as claimed in claim 1 including a line of weakening between the attached end and the releasable end to facilitate severance of said tape at the time of diaper removal.

8. A pressure-sensitive tape fastener for a disposable diaper as claimed in claim 2 including a line of weakening between the attached end and the releasable end to facilitate severance of said tape at the time of diaper removal.

9. A pressure-sensitive tape fastener for a disposable diaper as claimed in claim 3 including a line of weakening between the attached end and the releasable end to facilitate severance of said tape at the time of diaper removal.

10. A pressure-sensitive tape fastener for a disposable diaper as claimed in claim 4 including a line of weakening between the attached end and the releasable end to facilitate severance of said tape at the time of diaper removal.