Absorbent product provided in roll form

A supply of absorbent panty liner pads formed by a contiguous longitudinal array of pad segments forming a strip. The strip has locally weakened zones to facilitate tearing off segments from the strip without the use of a cutting tool. Each pad segment is shorter than a standard panty liner pad so that approximately three segments are required to form a standard length pad. By tearing off two, three, four, or five segments in one piece, the user can create a panty liner having a short, standard, long or extra long length to suit her needs on any given day. The strip is wrapped upon itself into a roll so that pressure sensitive positioning adhesive strips are placed into contact with release surfaces formed on the strip, thereby protecting the adhesive prior to use without the need for release paper.

FIELD OF THE INVENTION
 The current invention is directed to absorbent products such as panty
 liners, sanitary napkins, incontinence pads and the like. More
 specifically, the current invention is directed to an absorbent product
 provided in roll form that is segmented to allow the user to customize the
 length of the product and that eliminates the need for release paper.
 BACKGROUND OF THE INVENTION
 In the past, absorbent pads such as panty liners, sanitary napkins and
 incontinence pads have been sold in fixed lengths. Typically, the user
 will desire a longer length on those days when she expects a large flow
 and a shorter length when she expects a small flow. However, absorbent
 pads are generally sold in only two predetermined lengths--standard and
 long. Consequently, a user whose needs could be optimally met by a pad
 having an intermediate length between standard and long, or by a very
 short or very long pad, will have to settle for a pad having less than
 optimal length. Moreover, even if the user finds that "standard" and
 "long" pads are of suitable length, she must still purchase and store both
 types so that the appropriate pad can be selected on any given day.
 Consequently, it would be desirable to provide an absorbent pad in a
 continuous strip, preferably in roll form, in such a manner that the user
 could readily customize the pad length to her individual needs on any
 given day.
 Past approaches to providing absorbent pads in roll form have not been
 entirely adequate. Generally, such rolls contain pads of fixed length,
 offering the user no more flexibility in terms of pad length than when
 buying individual pads. Illustrative of this approach are U.S. Pat. Nos.
 3,183,910 (Patterson) and 4,598,528 (McFarland). Another approach,
 disclosed in U.S. Pat. No. 4,505,704 (Roeder), allows the user to cut the
 rolled pad into any desired length. However, it is necessary to either
 supply the roll in a dispenser having a cutting edge, or to instruct the
 user to employ scissors to cut the roll into individual pads of the
 desired length.
 Consequently, it would be desirable to provide a pad in roll form that
 could be divided into pads of various lengths without requiring the user
 to carry about a special dispenser or a pair of scissors.
 Another problem associated with traditional absorbent pads arises because
 they are generally held in place by pressure sensitive adhesive, typically
 a double sided tape or a hot melt type glue, disposed on the garment
 facing side of the pad. The pressure sensitive adhesive holds the pad in
 place by adhering it to the crotch of the wearer's undergarment. The
 pressure sensitive adhesive is covered with release paper that protects
 the adhesive from dirt and unintended adhesion during manufacture,
 packaging and storage. Since the release paper must be removed by the user
 just prior to application of the product to an undergarment, its presence
 creates waste and complicates the utilization of the product.
 Consequently, it would be desirable to provide an absorbent pad in roll
 form that utilized pressure sensitive adhesive strips for pad placement
 but that did not require release paper.
 SUMMARY OF THE INVENTION
 It is an object of the current invention to provide an absorbent pad in
 roll form that can be divided into pads of various lengths, without
 requiring the user to carry about a special dispenser or a pair of
 scissors, and that utilized pressure sensitive adhesive for pad placement
 but that did not require release paper to protect the adhesive. These and
 other objects are accomplished in a strip of absorbent product from which
 individual absorbent pads may be torn, comprising (i) longitudinally
 extending body facing and garment facing surfaces formed on opposing sides
 of the absorbent product strip, (ii) a longitudinally extending strip of
 absorbent material having a length, a width, and first and second
 longitudinally extending surfaces, and (iii) a longitudinally extending
 fluid impervious barrier strip, at least a portion of the barrier strip
 covering the first surface of the absorbent material strip and forming the
 garment facing surface. The strip of absorbent material has a plurality of
 weakened zones. The weakened zones are arranged along lines extending
 substantially transversely across the width of the absorbent material
 strip so as to form preferential tearing lines. The tearing lines are
 spaced at predetermined intervals along the length of the absorbent
 material strip so to form strip segments.
 In one embodiment of the current invention, the absorbent product strip is
 formed into a roll by wrapping the absorbent material strip, with the
 barrier strip covering the first surface, onto itself so as to bring the
 body facing surface into contact with the garment facing surface. In this
 embodiment, the strip of absorbent product further comprises (i) a strip
 of pressure sensitive adhesive disposed on the garment facing surface, and
 (ii) a release surface formed on the body facing surface. When the
 absorbent product strip is wrapped into the roll, the strip of pressure
 sensitive adhesive is brought into contact with the release surface,
 thereby protecting the adhesive.
 The current invention also encompasses a method of making absorbent pads
 for use in absorbing body fluids so as to prevent staining of a user's
 garment. In one embodiment of the method, the absorbent pads are made by
 the steps of (i) forming a longitudinally extending strip of absorbent
 material having a length and a width, (ii) forming a plurality of weakened
 zones in the strip of absorbent material, the weakened zones arranged
 along lines extending substantially transversely across the width of the
 strip of absorbent material so as to form preferential tearing lines, the
 tearing lines spaced at predetermined intervals along the length of the
 strip of absorbent material so as to define strip segments therebetween,
 and (iii) tearing a plurality of contiguous strip segments from the
 absorbent material strip by tearing along one of the weakened zones so as
 to form an absorbent pad formed by the plurality of contiguous strip
 segments.
 Accordingly, the claimed invention relates to a supply of absorbent pads
 for use in absorbing body fluids so as to prevent staining of a user's
 garment, comprising a longitudinally extending strip of absorbent pad
 segments, the pad segments having a predetermined uniform interval length
 of from about 1 to about 3 inches said strip being tearable into
 individual absorbent pads without the use of a dispenser having a cutting
 edge or scissors, said strip of absorbent pad segments having
 longitudinally extending first and second edges and: a) a longitudinally
 extending body facing surface defined in part by a first major surface of
 a longitudinally extending strip of absorbent material having a plurality
 of substantially transverse weakened zones forming preferential tearing
 lines, said weakened zones spaced at predetermined intervals along said
 absorbent material strip corresponding to the predetermined interval
 lengths of said pad segments; (b) a longitudinally extending fluid
 impervious barrier strip, wherein a portion of said barrier strip overlies
 and is adhesively bonded to the absorbent material covering a second major
 surface, opposite the first major surface of said absorbent material strip
 and forming a longitudinally extending garment facing surface of said
 strip of absorbent pad segments, and portions of said barrier strip
 forming first and second portions of said body facing surface adjacent
 said first and second longitudinally extending edges, respectively; (c) a
 pressure sensitive adhesive disposed on said garment-facing surface of
 said strip of the absorbent pad segments; and (d) a continuous,
 longitudinally extending release surface formed on said first and second
 portions of said body-facing surface formed by said barrier strip,
 proximate the edges; wherein said fluid impervious barrier strip forms a
 fluid barrier which prevents fluid leakage during use of said absorbent
 pads, said longitudinally extending strip of absorbent pad segments is
 wrapped around itself into a roll to place said pressure sensitive
 adhesive into contact with at least a portion of said release surface and
 said individual absorbent pads are formed of a plurality of absorbent pad
 segments.
 The claimed invention also relates to a method of making absorbent pads,
 comprising the steps of: (a) forming a longitudinally extending strip of
 an absorbent element, said absorbent element having first and second
 opposed longitudinally extending surfaces, longitudinally extending edges,
 and a plurality of substantially transverse weakened zones forming
 preferential tearing lines, said weakened zones spaced at predetermined,
 uniform intervals about 1 to about 3 inches along said absorbent element
 to define absorbent pad segments therebetween; (b) overlaying said second
 surface, said longitudinally extending edges, and a portion of said first
 surface, with a fluid impervious barrier strip; (c) depositing a pressure
 sensitive adhesive on at least a portion of said barrier strip overlaying
 said second surface; (d) forming a release surface on at least a portion
 of said barrier strip overlaying said portion of said first surface; and
 (e) wrapping said strip of absorbent element around itself into a roll so
 as to place said pressure sensitive adhesive into contact with at least a
 portion of said release surface.

DESCRIPTION OF THE PREFERRED EMBODIMENT
 A supply of panty liner pads, provided in a strip 1 according to the
 current invention, is shown in FIGS. 1 and 2. As shown best in FIG. 2, the
 panty liner supply strip 1 is comprised of a longitudinally extending
 strip of an absorbent material 3 and a longitudinally extending barrier
 strip 7. The absorbent strip 3 has an upper surface 4, which forms a
 portion of the body facing surface of the product in use, and a lower
 surface 5. In the preferred embodiment, the absorbent strip 3 is a
 non-woven fusible fiber pulp fabric available from Personal Products Co.
 of Miltown, N.J., or HILOFT fabric, a pulp fabric available from Scott
 Paper Company.
 As shown in FIG. 2, the entirety of the lower surface 5 of the absorbent
 strip 3 is covered by a longitudinally extending fluid impervious barrier
 7. The barrier 7 forms the garment facing surface 16 of the product in
 use. The barrier 7 is attached to the lower surface 5 of the absorbent
 strip by means of a layer of adhesive 6, such as Scotch SPRA-MENT
 adhesive, available from 3-M Company, St. Paul, Minn. In the preferred
 embodiment, the barrier 7 is formed from a 1.35 mil thick layer of 40%
 high density and 60% low density polyethylene. Suitable barrier films are
 available from Banner Packaging Inc., Winnenbago, Wis.
 The barrier 7 could also be formed from a polytetraflouroethylene (TEFLON)
 film. Such a film would not require a release coating to form a release
 surface since it inherently forms a low bond strength with adhesives.
 However, in such cases, the barrier film would have to be treated on the
 garment facing side to ensure that the adhesive remained in place.
 In addition to covering the lower surface 5 of the strip of absorbent
 material 3, the barrier 7 is wrapped around the longitudinally extending
 edges 13 of the absorbent strip 3 and the portions of its upper surface 4
 adjacent each of the edges 13, as shown in FIG. 2. By covering the edges
 13 of the absorbent strip 3, the barrier 7 prevents side leakage of fluid
 that might stain the user's undergarment. By covering portions of the
 upper surface 4 of the absorbent strip 3, the barrier 7 creates a surface
 on which a release surface can be formed, as discussed further below. The
 barrier 7 is attached to the upper surface 4 of the absorbent strip 3 by
 means of a strip of adhesive 15, such as Fuller L-3585, available from,
 H.B. Fuller Co., St. Paul, Minn.
 As is well known in the art, panty liner pads are utilized by attaching
 them to the crotch portion of the user's undergarment using a positioning
 adhesive. Consequently, pressure sensitive adhesive 8 is applied to the
 barrier 7 adjacent each of the edges 13 of the absorbent strip 3. In the
 preferred embodiment, the adhesive 8 is applied in continuous,
 longitudinally extending strips that run the length of the absorbent strip
 3. However, as those skilled in the art will readily appreciate, the
 adhesive 8 could also be applied in intermittent strips, patches or a
 variety of other patterns. In the preferred embodiment, the pressure
 sensitive adhesive is of the hot melt type, such as an A-B-A block
 copolymer (i.e., styrene-ethylene-butylene-styrene block copolymer). By
 way of example, the pressure sensitive adhesive may be Fuller HM-6514,
 available from, H.B. Fuller Co., St. Paul, Minn., applied at approximately
 74 mg/in.sup.2. Alternatively, a double sided adhesive tape could be
 utilized. As will be discussed further below, according to the current
 invention, no release paper is necessary to protect the pressure sensitive
 adhesive 8 prior to application of the panty liner pad to the
 undergarment.
 As shown in FIGS. 1 and 2, a release surface 9 is formed on the portions of
 the barrier 7 that cover the portions of the upper surface 4 of the
 adhesive strip 3 adjacent its edges 13. In the preferred embodiment, the
 release surface is formed by coating the portions of the barrier 7 with
 silicone prior to joining the barrier to the absorbent strip 3. The
 silicone coating is deposited in a continuous, longitudinally extending
 strip and may be applied by a variety of methods, such as direct or
 reverse gravure coaters or ink jet printing. After it is applied to the
 barrier film 7, the silicone coating may be cured, such as by ultraviolet
 curing, heat curing or electron beam curing. Suitable coating can be
 performed by Release Technologies of Chicago, Ill.
 As shown in FIG. 1, according to an important aspect of the current
 invention, the supply strip of panty liners 1 is formed by a number of
 contiguous segments 2 arranged longitudinally along the length of the
 strip. Each segment 2 is delineated from the adjacent segments by
 preferential tear lines 11 that extend transversely across the width of
 the absorbent strip 3, as shown in FIG. 1. The tear lines 11 are formed by
 locally weakening the absorbent strip 3. In the preferred embodiment, the
 tear lines 11 are formed by perforating the absorbent strip 3. As a result
 of this localized weakening of the strip 3, the application of sufficient
 tearing force to the absorbent strip will cause a segment to separate from
 the strip at a tear line 11 between segments, rather than tearing within a
 segment.
 In the preferred embodiment, preferential tearing along lines 11 is further
 enhanced by the formation of notches 10 in the portions of the barrier 7
 covering each of the sides 13 of the absorbent strip 3. In the preferred
 embodiment, the notches 10 are formed by cutting slits in the barrier 7.
 As shown in FIG. 1, the notches 10 in the barrier 7 are longitudinally
 aligned with the tear lines 11 in the absorbent strip 3. The notches 10
 act to concentrate the stress applied to the panty liner supply strip 1
 when a segment 2 is torn off, thereby facilitating the fracture of the
 barrier 7 at the notch 10 location. Since, as discussed below, each panty
 liner may comprise several contiguous segments 2, one or more intermediate
 tear lines 11 will remain within the panty liner after it has been
 separated from the strip 1. Thus, unlike the absorbent strip 3, the
 barrier 7 is not perforated at the tear lines 11 since such perforations
 could result in leakage through such intermediate tear lines.
 According to an important aspect of the current invention, the length L of
 each segment 2, shown in FIG. 1, is less than that required for a panty
 liner pad. In fact, the length L should be sufficiently small so that
 approximately three segments 2 are required to form a standard size panty
 liner pad 14, shown in FIG. 3. Thus, should the user expect only a small
 stain on any given day, she will tear off two segments 2 in one piece to
 form a short panty liner pad. By tearing off three, four or five segments
 2 in one piece, the user can create a standard length, long or extra long
 panty liner pad. In the preferred embodiment, the length L is less than
 approximately four inches, preferably in the range of approximately one to
 three inches, most preferably approximately two inches. Moreover, in the
 preferred embodiment, the overall length of the panty liner strip 1 is at
 least approximately fifty inches, preferably approximately one hundred to
 one hundred fifty inches. Most preferably, the overall length is
 approximately one hundred thirty two inches so that, if the segments 2 are
 two inches long and a standard size pad is three segments long (i.e., six
 inches), a single strip 1 will contain a supply of at least twenty two
 standard size panty liner pads.
 As can readily be appreciated, the user is given considerable flexibility
 in choosing the pad length that will suit her needs on any given day,
 without the necessity of purchasing pads in varying length. Since the
 panty liner supply strip 1 is preferentially weakened between each
 segment, no special dispenser is required to cut the segments from the
 strip 1, nor need the user carry a pair of scissors.
 According to another important aspect of the current invention, the panty
 liner supply strip 1 can be wrapped upon itself to form a roll 12, with
 the body facing surface 4 of the strip in contact with the garment facing
 surface 16, as shown in FIG. 4. By wrapping the strip 1 so that the
 garment facing surface 16 formed by the barrier 7 is wrapped upon itself,
 the strips of adhesive 8 are placed against the release surfaces 9, with
 the release surfaces being disposed on the outside of the roll 12, as
 shown in FIGS. 4 and 5. Advantageously, the release surfaces 9 are wider
 than the strips of pressure sensitive adhesive 8 so as to provide
 sufficient tolerance to ensure that all of the adhesive will contact a
 release surface. In the preferred embodiment, each release surface 9 is
 approximately 0.4 inch wide and each strip of pressure sensitive adhesive
 8 is approximately 0.25 inch wide.
 As can be appreciated, the pressure sensitive adhesive strips are protected
 from contamination or inadvertent sticking prior to use without the
 necessity of release paper. The user merely pulls the panty liner strip 1
 from the roll 12 and tears off a sufficient number of segments 2 in one
 piece to form a panty liner pad to suit her needs on that occasion and
 applies the pad to an undergarment.
 Although the current invention has been discussed with reference to panty
 liner pads, the invention is also applicable to other types of absorbent
 products, such as sanitary napkins and incontinence pads. Accordingly, the
 present invention may be embodied in other specific forms without
 departing from the spirit or essential attributes thereof and,
 accordingly, reference should be made to the appended claims, rather than
 to the foregoing specification, as indicating the scope of the invention.