US2773503A

US2773503A - Absorbent product

Info

Publication number: US2773503A
Application number: US454152A
Authority: US
Inventors: Brownlee Robert Nelson; Griswold Hector Wallace
Original assignee: Personal Products Co
Current assignee: Personal Products Co
Priority date: 1954-09-03
Filing date: 1954-09-03
Publication date: 1956-12-11
Anticipated expiration: 1973-12-11

Description

DCC- 11, 1956` R. N. BROWNLEE ET A'. 2,773,503

ABSORBENT PRODUCT Filed Sept. 3, 1954 United States Patent() ABSORBENT PRODUCT Application September 3, 1954, Serial No. 454,152

6 Claims. (Cl. 12S-290) This invention relates to absorbent dressings and more particularly to improvements in sanitary napkins which have a cover or wrapper of pervious, non-woven fabric.

Conventional sanitary napkins are comprised of an absorbent pad or core enclosed within a cover of pervious fabric. The cover extends beyond the ends ofthe absorbent pad to provide attaching tabs for fastening the napkin in position by pinning to an undergarment orattaching to a supporting belt. Many sanitary napkins have a .cotton gauze cover because cotton gauze is readily permeable and provides attaching tabs with sufficient strength to insure secure attachment of the napkin. However, gauze napkin covers are being replaced to a great extent by non-woven fabrics because gauze is expensive and uncomfortable due to its chaiing properties in contradistinc-t tion to non-woven fabrics which are less expensive and which impart a smoother, softer surface to the napkin and are therefore less irritating and more comfortable to the wearer. i

Most non-woven fabrics acceptable as sanitary napkin covers, such as a rayon or cotton web formed by carding, garnetting or air deposition of fibers, dovnot possess sufcient strength to provide tabs which can be securely attached in the conventional manner. It is customary practice, therefore, to incorporate into the napkin a wide, high weave count gauze web whose ends are substantially coextensive with the ends of the non-woven fabric cover and in this manner provide reinforced attaching tabs. While such napkins have received wide acceptance, they are still subject to numerous disadvantages. The tabs often tear, even though they are reinforced. The napkins are uncomfortable because the gauze web, due to its width and tendency to distort, bunches or ropes in use, particularly in napkins having folded tabs. The cost of the gauze web continues to remain a significant part of the total cost of the napkin for it is necessary to use a Wide, high weave count gauze web substantially the width of the napkin in order to provide tabs with reasonable attaching strength, Further, considerable difficulty is experienced in slitting gauze stock into webs of desired widths and in `handling the gauze during manufacture of napkins because gauze is unstable and unravels readily.

We have found that these and other disadvantages of sanitary napkins of this type may be obviated by providing the napkins with a gauze web that has been dimensionally stabilized.

Dimensionally stabilized gauze refers to gauze which resists distortion from its general woven configuration by those forces encountered during conditions of normal use which cause gauze to unravel, rope or otherwise lose its woven structure. The threads of such gauze tend to remain in position in contradistinction to the threads of unstabilized gauze, which may be easily displaced or removed.

By incorporating a dimensionally stabilized gauze web into the napkins, substantial savings in the cost of manufacture can be effected. A superior, more comfortable napkin is obtained because the web resists bunching or 2,773,503 Patented Dec. 11, k19576A ice , 2 roping in use and provides, in conjunction with the nonwoven fabric cover, attaching tabs which `are stronger than those provided by an unstabilized gauze web. Further, the manufacturing problems encountered in slitting and handling unstabilized gauze can be substantially reduced.

To more fully understand the general nature of the invention, reference is made to the accompanying drawing which illustrates a preferred embodiment.

In the drawings: f

Fig. 1 is a perspective view of a sanitary napkin with a non-woven fabric cover and incorporating a dimensionally stabilized gauze web in accordance with the present invention. The center portion of the napkin is cut away in part to reveal its inner construction.

Fig. 2 is a perspective view of the dimensionally sta# bilized gauze web incorporated into the napkin of Fig. 1 and illustrates a way in which dimensional stability of'the gauze web may be obtained.

Fig. 3 is a cross-sectional view along the lines 3 3 of the napkin illustrated in Fig. l.

Fig. 4 is an enlarged plan view of the gauze web illustrated in Fig. 2.

In the embodiment of the invention illustrated in the drawings, a napkin 1 is comprised of an elongated absorbent pad or core 2 having a dimensionally stabilized gauze web 3 superimposed thereon. The pad and the gauze web are enclosed within a pervious, non-woven fabric cover 4. The absorbent pad 2 may be of any desired construction and may consist of multi-ply tissue paper, loosely matted wood pulp, or other absorbent fibers and combinations thereof preferably selected and arranged to obtain high absorbency. Generally, the pad is elongated with rounded ends and in average size is approximately seven and one-half inches long by three inches wide.

The dimensioually stabilized gauze web 3 is centrally superimposed on the absorbent pad 2 with the major dimension of the'absorbent pad. The ends 5 of the gauze web extend beyond the ends of the absorbent pad to provide tabs for attaching the napkin in position to a supporting belt or the like. In a sanitary napkin of average size, a dimensionally stabilized gauze web about one and one-quarter inches 'wide and eighteen inches long and with a thread count of 14 x 8 (fourteen lengthwise or warp threads per inch and eight crosswise or lling threads per inch) is satisfactory. The gauze web may be composed of' various fibers, such 'as natural fibers, synthetic fibers, and the like, alone or in combination. Rayon or cotton gauze is particularly suitable since such gauze is readily avail-V able, inexpensive and can be dimensionally stabilized with little difficulty.

The absorbent pad and the stabilized .gauze web are enclosed in the pervious, non-woven fabric cover 4, which is folded around the pad and the gauze web, and prefer ably in such a manner as to overlap on one face of the pad, thereby providing the opposite face with a smooth, uninterrupted surface which can be applied next to the body of the wearer of the napkin. The ends of the cover 4 are made substantially coextensive with the ends 5 of the gauze insert 3 and in combination with the insert ends provide tabs for attaching the napkin. While the non-woven fabric cover may consist of a web of bers prepared by any of the conventional processes, it is preferred that it be a web having a large percentage of bers substantially in alignment with the length of the cover; i. e. in the direction of the napkins long dimension. The cover may be treated or processed to increase its softness and fluiiness.

The gauze web 3 may be obtained in desired widths by slitting larger stock rolls of gauze that have been dimensionally stabilized. Dimensional stability of the gauze may be obtained, .as shown in Figs. .2 and 4, by securing the warp threads 6 and lling threads 7 in position at their points of intersection by locally applying a bonding material 8 to these `points 'or by inte'rrnixing thermoplastic fibers with thefibers which form the gauze threads and subsequently hot calendering thegauze woven from the threads to melt the thermoplastic fibers thereby securing the threads at their points of intersection.

While it is apparent that a more stable gauze web may be obtained by securing the threads Vat every intersection, it is not necessary for `purposes of this invention. Acceptable stabilization of the gauze can be obtained by securing the threads at alternate intersections, as shown in Fig. 4, `and other arrangements and variations in bonding patterns are satisfactory, providing the gauze resulting therefrom is adequately integrated to resist distortion by the forces normally encountered in use. Effective stabilization of gauze may .be `obtained by bonding the gauze threads at every fourth or fifth intersection; or by bonding every fifth filling thread to the warp threads that it intersects.

The bonding agent should be present in'suicient quantities to insure effective stabilization of the gauze without unduly imparting stiffness and hardness. Preferably, the bonding material should be applied only to the points of intersection of the gauze threads with the remaining partsof the threads free from the bonding material since a more supple stabilized gauze web is obtained. Based upon the dry weight of gauze, gauze having 20-25 percent of the bonding material as solids provides an eiectively stabilized gauze which is suiciently liexible for the purposes herein described. The bonding material should also be tiexible, compatible with `conditions of use and should be non-irritating, colorless, odorless and capable of withstanding aging process. A particularly suitable bonding material consists of aqueous polyvinyl chloride with 40 to 50 percent resin solids and plasticized with 35 percent dibutyl phthalate. Another suitable bonding agent is aqueous polyvinyl acetate plasticized with 20 percent of the same plasticizing agent.

It is apparent that changes, variations and modications of the invention as illustrated in the foregoing embodiment may be made withoutV departing from the scope of the following claims.

We claim:

l. A sanitary napkin comprising an absorbent pad, a gauze web in the form of a narrow reinforcing strip adjacent the pad and having ends extending beyond the ends of the pad, a separate woven fabric covering said pad and said web and having ends substantially coextensive with the ends of thegauze web,l the threads of the web being secured at a multiplicity of points where they-intersect each other whereby the gauze web has imparted to it the characteristic of resisting those forces encountered during conditions of normal use which cause a gauze web to distort.

2. A sanitary napkin comprising an absorbent pad, a wauze web in the form of a narrow reinforcing strip adjacent the pad and having ends extending beyond the ends of the pad, a separate non-woven fabric covering said pad and said web and having ends substantially coextensive with the ends of the gauze web, the threads of the web being secured at a multiplicity of points where they intersect each other by an adhesive material whereby the gauze web has imparted to it the characteristic of resisting those forces encountered during conditions of normal use which cause a. gauze web `to distort.

3. A sanitary napkin comprising an absorbent pad, a gauze web in the Vform of a narrow reinforcing strip adjacent the pad and having ends` extending beyond the` ends of the pad, a separate non-woven fabric covering said pad and said web and having ends substantially co extensive with the ends of the gauze web, the threads of the Web being secured at a multiplicity of points where they intersect each other by plasticized polyvinyl acetate whereby the gauze web has imparted to it the characteristic of resisting those forces encountered during conditions of normal use which cause a gauze web to distort.

4. A sanitary napkin comprising an absorbent pad, a gauze web in the form of a narrow reinforcing strip adjacent the pad vand having ends extending beyond the ends of the pad, a separate non-woven fabric covering said pad and said web and having ends substantially coextensive with the ends of the gauze web, the threads of the web being secured at a multiplicity of points where they intersect each other by plasticized polyvinyl chloride whereby the gauze web hasimparted to it the characteristic of resisting those forces encountered during conditions of normal use which cause a gauze web to distort.

5. A sanitary napkin comprising an absorbent pad, a gauze web inthe form of a narrow reinforcing strip adjacent the pad and having ends extending beyond the ends of the pad, a separate non-woven fabric covering said pad and said web and having ends substantially coextensive with the ends of the gauze web, the threads of the web being secured at a multiplicity of points where they intersect each other with a bonding material, said bonding mai terial being present as solids, based upon the dry weight of the gauze web, to the extent of 20 to 50 percent whereby the gauze web has imparted to it the characteristic of resisting those forces encountered during conditions of normal use which cause a gauze web to distort.

6. A lsanitary napkin comprising an absorbent pad, a gauze web in the `form of a narrow reinforcing strip adjacent the pad and having ends extending beyond the ends of the pad, a separate nonwoven fabric covering said pad and said web and having ends substantially coextensive with the ends of the gauze web, the threads of the web being secured at a multiplicity of points where they intersect each other with a bonding material, said bonding material being present as solids, based upon the dry weight of the gauze web, to the extent of 20 to 25 percent whereby the gauze web has imparted to it the characteristic of resisting those forces encountered during conditions of normal use which cause a gauze web to distort.

References Cited in the tile of this patent UNITED STATES PATENTS 2,564,689 Harwood et al. Aug..21, 1951