Patent Publication Number: US-3874386-A

Title: Pressure-sensitive tape fastener for disposable diapers

Description:
United States Patent Kozak Apr. 1,, 1975 [54] PRESSURE-SENSITIVE TAPE FASTENER 3,642,001 2/1972 Sabee 128/287 OR DISPOSABLE DIAPERS 3,646,937 3/1972 Gellert l28/287 Theodore F. Kozak, Peekskill, NY.  
 Union Carbide Corporation, New York, N.Y.  
 Filed: Mar. 19, 1974 Appl. N0.: 452,609  
 Related US. Application Data Continuation-impart of Ser, No. 402,088, Oct. 1, I973, abandoned Inventor:  
 Assignee:  
 US. Cl. 128/287, 128/284 Int. Cl. A6lf 13/16 Field of Search 128/284, 286, 287, 290 R,  
 References Cited UNITED STATES PATENTS 12/1971 Endres l28/287 Primary ExaminerAldrich F. Medbery Attorney, Agent, or Firm-Clement .l. Vicari [57] ABSTRACT A disposable diaper having a top sheet, a backing sheet and an absorbent core interposed therebetween and a pressure-sensitive tape fastener having a fixed end segment, a middle segment and a releasable end segment which is folded in a manner such that the releasable end segment and the :middle segment are superimposed over the fixed end segment with the lower surface of the releasable end segment being in contacting relation and releasably secured to the lower surface of the middle segment.  
 9 Claims, 6 Drawing Figures are pressure-sensitive tape fasteners which are pre- I ferred over conventional safety pins because of the elimination of the well-known danger incident to the use of safety pins.  
  Unfortunately, however, the known pressuresensitive tape fasteners for diaper use are not entirely satisfactory from a practical standpoint. For example, in general, some types of pressure-sensitive tape fasteners utilize a throw-away release paper which is normally adhered to a portion of the tape tab. When it is desired to secure the diaper on an infant, the operator removes the release paper from the tap exposing an adhesively treated surface which is, thereafter, fixed in adhesive relation on the desired surface of the diaper. Since this operation is conducted while the diaper is on the infant, it is difficult for the operator to both apply the diaper to the infant while at the same time releasing the release paper from the tape fastener.  
  It is therefore an object of the present invention to provide an improved pressure-sensitive tape fastener for a disposable diaper which does not utilize a disposable throw-away release material, such as a release paper, with the pressure-sensitive tape fastenen Another object of the present invention is the provision of an improved pressure-sensitive tape fastener for a disposable diaper which is easily manufactured, and is simple to apply to an infant.  
  These and other objects will become apparent from the following description of the invention taken in conjunction with the accompanying drawings in which:  
  FIG. 1 is a perspective view looking upwardly at the bottom of the improved pressure-sensitive tape fastener of the present invention showing the location of the adhesive surfaces and the release surface of the fastener. 7  
  FIG. 2 is a side view showing the pressure-sensitive tape fastener indicating the location of the folds of the fastener.  
  FIG. 3 is a fragmentary perspective view ofa disposable diaper showing the position of the tape fastener in non-operating position, i.e., only one end affixed to a corner of the diaper.  
  FIG. 4 is a view showing the tape fastener in operating position. i.e., both ends affixed to adjoining corners of a diaper in securing position.  
  FIG. 5 is a view similar to FIG. 1 showing however, a modified form of the pressure-sensitive tape fastener wherein a portion of the free end is not treated with adhesive.  
  FIG. 6 is a view similiar to FIG. 1 showing however, another embodiment of the pressure-sensitive tape fastener wherein portions of the middle segment and releasable end segment contain laterally extending strips of release material on their surfaces.  
  Broadly contemplated, the present invention provides an improvement in a disposable diaper having a top sheet, a backing sheet and an adsorbent core interposed therebetween, the improvement being a pressure sensitive tape fastener having an upper surface and a lower surface, the latter being divided widthwise into two end segments at least one of which is adhesively treated and a middle segment containing a release agent. One of the end segments is a fixed end segment which is permanently secured to the backsheet and the other end segment which is adhesively treated is a releasable end segment. The tape fastener is folded in a manner such that the releasable end segment and the middle segment are superimposed over the fixed end segment with the lower surface of the releasable end segment being in contacting relation and releasably secured to the lower surface of the middle segment.  
  Referring to FIG. 1 of the drawings, it will be seen that the pressure-sensitive tape fastener of the present invention, generally indicated by reference numeral 10 has an upper surface 11 and a lower surface 12. The lower surface is divided widthwise into three segments, including two end segments or ends 13 and 15 and a middle segment 14. Depending upon the positioning of the tape fastener on the diaper, either end 13 or 15 can be termed a fixed or attached end in which case the other end would be termed a free or releasable end. The pressure-sensitive tape is preferably a paperbacked tape but it can also be any of several well-known commerical types including the type having a polyethylene backing. In either case, it can be used with or without reinforcing. At least one of the end segments 13 and 15 on the lower surface 12 are coated with a pressuresensitive adhesive which can be any of the conventional types well known in the art. The middle segment 14 is treated with a release agent, so that when the releasable end is adhered to the middle segment, as will hereafter be described, there is a minimal adhesive attachment therewith. Thus, according to the invention, the adhesive portions and the release portion are all disposed on the same side of the pressure-sensitive tape i.e., the lower surface 12 of the tape. When the pressuresensitive tape fastener is in non-operating position, i.e., prior to securing the diaper on an infant, the pressuresensitive tape has a system of folds as indicated in FIG. 2.  
  Referring specifically to FIG. 2, it will be seen that the folds occur at the inward ends of the segments 13 and 15 with the releasable end 15 being superimposed and in contact with the middle segment 14 containing the release agent. The resultant configuration depends upon which end is the fixed end. When segment 13 is the fixed end i.e., the end permanently secured to the diaper, the resultant configuration has an S-shape, whereas if the fixed end is segment 15, then the resultant configuration is Z-shaped.  
  The pressure-sensitive tape fastener can be employed with any conventional disposable diaper particularly of the kind that has a plastic backing sheet. Merely as illustrative, of the kind of diaper to which the invention is readily adapted, reference is made to the diaper described in my copending application Ser. No. 3 l2,l 31 filed on Dec. 4, 1972.  
  It will be obvious 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 disclosure of the above copending application 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 to FIG. 3 which illustrates the location of the tape fastener in non-operating position, on a corner of a disposable diaper, the diaper generally designated by reference numeral 16 contains an absorbent core 17. The core can be formed from any well known material having good fluid-absorbing characteristics such as absorbent wadding, cellulosic fluff and the like. Preferably, however, the absorbent core is in the form of an absorbent pad which is substantially centrally located and sandwiched between the thin flexible backing sheet 18 of liquid impermeable material such as polyethylene film, and the thin flexible top sheet 19 also of a normally liquid impermeable material which has been treated such as by providing openings or slits therein so as to permit the passage of liquid therethough. It will be understood however, that both the top sheet 19 and backing sheet 18 may be any suitable material and need not be plastic, particularly when the diaper is to be covered with plastic panties or the like. In its preferred form, backing sheet 18 and top sheet 19 are of approximately equal size and are of a length and width slightly greater than the corresponding dimensions of the absorbent core 17. The edges of backing sheet 18 and top sheet 19 are sealed to each other (if plastic) around the entire periphery of the diaper and just outside the outermost edges of absorbent core (pad) 17.  
  The sealing can be accomplished by any convenient means, such as by the use of an adhesive, however heat sealing around the periphery of the diaper is preferred.  
  The pressure-sensitive tape fastener 10 has one end, e.g., the fixed end 13 which is strongly adhered and permanently secured to the backing sheet 18 as shown in FIG. 3 (for simplicity of illustration, only one tape 10 is-shown but it will be understood that normally two tapes are provided on two diaper corners in a complete diaper structure). When the pressure-sensitive tape fastener is fabricated from a thermoplastic material for application to a backsheet also of thermoplastic material, then the securing of the fixed end can be effected by heat sealing. However, when heat sealing is not possible, then the fixed end segment can be coated on the lower surface with an adhesive material so that both end segments would be adhesively treated. The other end of the tape, i.e., the releasable end when in nonoperating position, is superimposed over the middle segment 14, containing the release agent, and is adhesively, albeit minimally, secured thereto.  
  FIG. 4 illustrates the tape fastener 10 after the operator has released the releasable end 15 and positioned it on the adjacent corner of a diaper in securing engagement therewith.  
  A further embodiment of the tape fastener 10 is illustrated in FIG. 5. The releasable end 15 has an end portion 21 on the lower surface 12 which is not treated with adhesive material. The non-adhesive portion 21 is of a length which will permit the operator to grasp and hold the non-adhesive portion while releasing the releasable end 15 from the middle segment 14. Normally a minimum of about one-eighth inch in length is sufficient for accomplishing the above.  
  In another embodiment of the invention as shown in FIG. 6, the middle segment, 14 and the releasable end 15, have a system of release sections 22, and adhesive sections 23 laterally extending across the lower surface 12 of the middle segment 14 and the lower surface of the releasable end 15. These sections are characterized in that they also contain a release material and when superimposed over each other the release sections are in nonmating relationship, i.e., the release sections do not overlie each other. It will, of course, be understood that the release sections can be disposed on the lower surfaces of the middle and releasable end segments by other design configurations. Thus, the release sections can run in sections lengthwise across the lower surface of themiddle and end segments, the important criterion being that they be in non-mating relationship when folded in the S- or Z-fold on the diaper. The size of these sections should be such as to make the releasable end 15 easily releasable from the middle segment 14. Moreover the exposed adhesive portions on the lower surface of the middle and releasable end segments, i.e., those portions not having the release material thereon, should be sufficient to provide adhesive holding power when the tape fastener is in operating position. The size of the release portions and the adhesive portions required for the above purposes are easily ascertainable by those skilled in the art and hence no further detailed discussion appears necessary.  
  In a typical mode of operation, the operator unfolds the diaper and wraps it around the infant in the usual manner. The pressure-sensitive tape fastener 10 is in the non-operating position as shown in FIG. 3. The operator thereafter grasps the releasable end and releases it from the middle segment 14. The adjacent corners are urged towards each other and the operator positions and secures the releasable end on the backingsheet of the adjacent corner of the diaper as shown in FIG. 4. The operation is repeated on the other adjacent corners with sufficient force being exerted so as to provide a tight, comfortable fitting diaper.  
  As mentioned previously the end segments 13 and 15 of the tape fastener 10 can be treated on the lower surface 12 with a conventional adhesive material. The adhesive material should be of sufficient bond strength to adhere to the backing sheet 18 under normal stress and strain during movement of the infant. The middle segment 14 of the tape fastener 10 is likewise treated on the lower surface with a release agent so as to provide minimal adhesive attachment with the releasable end. Although a wide variety of release agents are known, a silicone treated lower surface of the middle segment is preferred.  
  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.  
 What is claimed is:  
  1. In a disposable diaper having a top sheet, a backing sheet and an absorbent core interposed therebetween, a means for providing self-stored protective access to a portion of the adhesive surface of a diaper tape fastener comprising, a pressure-sensitive tape fastener having an upper surface and a lower surface, said lower surface being divided widthwise into two end segments at least one of which is adhesively treated and a middle segment containing a release agent, one of said end segments being a&#39;fixed end segment which is secured to said backsheet, the other of said end segments being a releasable end segment; said fastener being folded in manner such that said releasable end segment and said middle segment are superimposed over said fixed end segment with the lower surface of said releasable end segment being in contacting relation and releasably secured to the lower surface of said middle segment.  
  2. A disposable diaper as claimed in claim 1 wherein said fixed end segment is secured to said backing sheet by adhering said fixed end segment to said backing sheet.  
  3. A disposable diaper as claimed in claim 1 wherein said backing sheet and said pressure-sensitive tape fastener are fabricated from a thermoplastic material and wherein said fixed end segment is secured to said backing sheet by heat sealing.  
  4. A disposable diaper according to claim 3 wherein said backing sheet and said pressure-sensitive tape fastener are fabricated from polyethylene.  
  5. A disposable diaper as claimed in claim 1 wherein said release agent on said middle segment is silicone.  
  6. A disposable diaper as claimed in claim 1 wherein said releasable end segment has an end portion on the lower surface of said pressure-sensitive tape fastener which is not treated with adhesive.  
 7. In a disposable diaper having a top sheet, a backing sheet and an absorbent core interposed therebetween, a means for providing self-stored protective access to a portion of the adhesive surface of a diaper tape fastener comprising, a pressure-sensitive tape fastener having an upper surface and a lower surface, said lower surface being divided widthwise into two end segments and a middle segment, one of said end segments being a fixed end segment which is secured to said backsheet, the other of said end segments being a releasable end segment, a system of release sections and adhesive sections disposed on the lower surface of said releasable end segment and said middle segment; said fastener being folded in manner such that said releasable end segment and said middle segment are superimposed over said fixed end segment with the lower surface of said releasable end segment being in contacting relation and releasably secured to the lower surface of said middle segment and being further characterized in that said release sections are in non-mating relationship when said fastener is in folded position.  
  8. A disposable diaper as claimed in claim 7 wherein said release sections and said adhesive sections extend laterally across the lower surface of said middle segment and said end segment.  
  9. A disposable diaper as claimed in claim 7 wherein said release sections and said adhesive sections extend lengthwise across the lower surface of said middle segment and said end segment.  
 Disclaimer 3,874,386.The0d0m F. Kosak, Peekskill, NY. PRESSURE-SENSITIVE TAPE FASTENER FOR DISPOSABLE DIAPERS. Patent dated Apr. 1, 1975. Disclaimer filed Aug. 18, 1977, by the assignee, Union Carbide Gowpomtz&#39;on. Hereby enters this disclaimer to claims 1 through 6 of said patent.  
 [Ofiicz&#39;al Gazette Octobe 18, 1.977.]