DE2525988A1 - DIAPER PAD - Google Patents

Description

PATENT ADVOCATE DIPL-ING

HELMUT GÖRTZ

6 Frankfurt am Main 70 Schneckenhofsir. 27 - Tel. 617079.

June 10, 1975 Gzm / Wa.

UNION CARBIDE CORPORATION, 270, Part Avenue, New York, N.Y 10017, U.S.A.

Diaper insert

The present invention relates to diapers, particularly to liners to throw away after single use for one or reusable diapers that are suitable for absorbency to increase and which can be used once and then be thrown away. In particular, those according to the invention Disposable diaper liners together with single or multiple uses Used diapers, with only the disposable diaper insert being excreted after soiling; this makes it possible continue to use the diaper.

Tangling away has been known for a number of years: finding them in broad consumer circles, both in private households and in hospitals and similar institutions. The current success of the disposable diapers is based on the fact that there is no need to store, wash and fold them in contrast to conventional cotton diapers.

In order to compete with the conventional product, the price of the disposable diaper must be relatively low; Farther the disposable diaper should be similar to the cloth diaper in terms of absorbency, softness, space requirements and fit.

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With both types of diapers, premature removal from the child adds considerably to the problems of consumption; this shows up either in the greater amount of work that is necessary is to clean the conventional diaper or in the cost necessary to replace the disposable diaper. These premature removal can be motivated by a number of factors, but the effect of partial saturation of the Diaper mainly contributes to this. If a child partially soils the diapers, then the mother or the consumer tends to replace the diaper immediately because they associate soiling with "diaper rash", odor, discomfort or such other characteristics.

Try to solve the problems with diaper aids, e.g. absorbent Single-use disposable diaper liners have not been satisfactory for a number of reasons. To illuminate this point, it should be noted that the conventional diapers suffer from one or more of the following disadvantages exhibit:

a) they do not have sufficient absorbency;

b) they are inconvenient for the consumer;

c) they have poor retention of liquid after absorbing it.

Of course, the terms "diaper aid", "diaper liners" be interpreted differently. In the context of the present invention, these terms denote absorbent Material or products that co-exist with conventional Diapers are used to achieve additional benefits,

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such as improved absorbency and decreased diaper drainage.

It is the object of the present invention to develop a diaper insert that can be used in conjunction with conventional diapers can be used in order to achieve increased absorbency in this way and which can be easily removed after soiling the diaper can be removed; this makes it possible to continue using the diaper.

Another object of the present invention is to develop a diaper insert for disposable diapers which allows to use the diaper for a longer period of time and is therefore more economical.

Another object of the invention is to develop a diaper liner for diapers that are highly liquid holding back.

Finally, it is the aim of the present invention to develop an insert for disposable diapers which has high absorption properties having.

Further features, advantages and possible applications of the invention emerge from the following description of an embodiment shown in the accompanying drawings, the drawings of which are seven figures contain.

Show it:

Fig. I shows a perspective view of the invention Diaper insert; some parts are open to other parts and certain details of construction

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to show.

Fig. 2 shows a section along line 2-2 of the Fig. I.

FIG. 3 shows an enlarged partial section of FIG. 2; then part of the diaper insert is shown in the unsaturated state.

Fig. H differs from Fig. 3 only in that the diaper insert is saturated with liquid.

Figure 5 is a plan view of a portion of the diaper liner in accordance with another method of the present invention Invention.

Figure 6 is a plan view of a diaper liner showing the contours of the absorbent material.

Figure 7 is a plan view of a conventional diaper with the diaper liner on top of the diaper.

The disposable diaper insert according to the invention consists at least from an absorbent pad, which is located between liquid-impermeable sheets, which are on the top and bottom are located; each sheet is made of a hydrophobic material such as a thermoplastic film; every movie is characterized by having a multitude of tubular UBd contains a system of wells across its openings Surface is distributed.

In Fig. 1 a disposable diaper insert is shown, generally designated 10, this consists of a right-angled absorbent pad 12, which is centrally mounted and, like a sandwich, is mounted between a thin, flexible, liquid-impermeable film ik or 16. The lower film

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_and the upper film 16 have a multiplicity of slots 18 and a system of depressions 22.

The foil 14 on the underside and the foil l6 on the Top side are roughly the same size, their length and height dimensions are slightly larger than the corresponding dimensions of the suction pad 12. The edges of the film 14 on the underside and the film 16 on the upper side are connected to one another, namely along the entire circumference of the insert 10 and outside the extreme corners of the suction pad 12. The bonding can be accomplished by any means, such as e.g. through the use of adhesive, but heat sealing is preferred (see the closure 20 around the periphery the deposit).

The absorbent pad 12 may consist of a plurality of layers including absorbent gauze paper or cotton. The cotton layers do not need to adhere to one another, as it is common practice to seal the layers with adhesive, to secure mechanically or in some other way, so that the relative position of the layers to each other is preserved and also the Shape of the absorbent pad; The same can be done with the insert according to the invention. The cotton wool can become a pillow you want Height to be stacked; this makes it possible to control the absorbency for any desired purpose.

Absorbent material that does not consist of fabric and wadding is of course also useful for the insert according to the invention. For example, absorbent pads that are not woven can be made up to any height and used instead of the absorbent pads described above. One such absorbent pad, which has been used very often for disposable diapers, is a pulp product which is made in the same way as a non-knitted fabric. Such absorbent pads

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can also be used for the deposits according to the invention.

The only criteria for use related to. of the present invention require that the material be absorbent is, can be made in the form of a pillow, with the waste products with which it will come in contact, is tolerated and does not irritate the skin.

Various natural and synthetic polymers are themselves absorbent, or can be made absorbent and are therefore useful as or in conjunction with the absorbent pad of the invention. A group of particularly preferred polymers includes insoluble hydrophiles, homopolymers and copolymers which form a gel upon absorption of water. These materials offer the advantage that they adhere firmly to the liquid and prevent the liquid from leaking out of the absorbent The object leaks and wets the skin or clothing with which the absorbent object is in contact.

The materials that are particularly useful in this context are made up of insoluble hydrophilic polymers composed of the following raw materials are represented: poly (alkylene oxides), e.g. poly (ethylene oxide), polyvinyl alcohol, Polyvinyl methyl ether, copolymers of maleic anhydride and ethylene, copolymers of maleic anhydride and vinyl methyl ether, polyelectrolytes, etc.

Insoluble hydrophilic polymers, sometimes called hydrogels, are particularly useful in connection with the present invention because they have the property of being very to be able to absorb large amounts of water (25 to 10 times as much their dry weight).

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The term insoluble, which is used in connection with these polymers, defines the formation of a gel that does not flow and does not give off water at the pressures that occur when using the products described above.

Insolubility can be accomplished by a number of methods, including ionizing and non-ionizing Radiation and crosslinking by covalent or ionic bonding.

A particularly preferred hydrogel comprises at least one hydropilic polymeric compound of the formula

-0

that has been networked;

• R,

stand for hydrogen, alkyl

groups and alkyl-substituted aryl groups; R until Rg stand for hydrogen, methyl, phenyl and vinyl groups and η is greater than one.

The hydrogels are polymeric compounds that show at least one of the structural units shown below:

-C t

H ι

C t

R,

-0

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R. to R. stand for hydrogen, methyl, phenyl and vinyl groups.

These hydrophilic polymers can be made up of carbon chains exist, which are networked with one another via carbon-carbon bonds; a small number of ties may comprise two oxygen atoms attached to carbon atoms are bound.

The crosslinking in the polymeric gel compounds can be over inter-molecular or intramolecular bonds occur, also about combinations of intra- and intermolecular bonds.

The hydrogels can be used for the diaper according to the invention are either in the form of thin, transparent foils that are sandwiched between them, or instead of the gauze layers the suction pad; they can also be stored in the fibers of the absorbent pillow as a powder in the form of chips will. The manner in which these materials are introduced into the pillow does not need special attention as it all that matters is that the polymers are in contact with the liquid that forms the top sheet of the absorbent article penetrates.

In the manufacture of the top and bottom sheets of the invention Diaper insert does not depend on a special chemical composition of the materials used,

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because it depends more on their physical properties than on their chemical properties. These materials should of course be thin _} flexible, self-supporting and water-impermeable sheets or films. Preferably they are thermoplastic films that can be hot-bonded to one another.

The top and bottom sheets can be an olefinic or vinyl film. For example, polyethylene can be used is approximately 0.4 to 1.5 mm thick. That kind of movie was already used very often in the past for disposable diapers and had stuck a pattern on the surface to simulate fabric. This manufacturing technique is also used in the Find diaper liners according to the invention application.

Any film that is suitable as a film for the underside is atich suitable as the upper side of the absorbent material according to the invention Diaper insert. However, a film, the fabric, is preferably used as the film for the underside and upper side resembles in appearance. A film that is particularly suitable for this consists of ethylene-ethyl acrylate. After slitting it is this copolymer is like a fabric, softer and stronger than a polyethylene film. The film should be about 0.4 to 2, ο mm thick (preferably 1.0 to 1.5 mm).

As described above, the film on the underside and on the top consists mainly of a liquid-impermeable one Material that must be provided with tube-like openings in order to be used as a diaper insert according to the invention works.

The term "tubular" refers to openings located on the lower and upper sheets that can open to allow liquid to pass under certain circumstances

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- ίο -

and which can close to delay the passage of liquid under certain circumstances. When they open then the tube-like openings should allow at least 20 milliliters of liquid to pass through within 10 seconds, when an area of about 835 qcra is wet. These openings can consist essentially of straight slots and holes exist.

The slots of the invention must be substantially straight because when they are curved or V-shaped they form Flaps on the surface of the film that open too easily and stay open. During such slots the passage ensure the liquid in the direction of the absorbent pad to a sufficient extent, they do not significantly reduce the Reflux of the liquid, which is the main object of the present invention. This disadvantage also exists when there are holes in the Film can be drilled by removing portions of the film, as opposed to piercing the film without removing filler material will. As a result, liquid can pass in both directions in an uncontrolled manner.

Fig. 1 shows the preferred arrangement of the slots. The slots 18 are arranged in longitudinal rows so that each row forms a longitudinal array of parallel straight slots, each slot forming an angle with the longitudinal axis of the row. Adjacent rows are similarly arranged, except that the slots are arranged so that the end points of each slot line up between the end points of corresponding slots in the adjacent rows. The slots should be between 0.076 cm and 0.63 cm long. Preferably there are about 30 to 150 slits per 6 cm ² ; each of these slots is approximately 0.17 cm to 0.5 cm long. The pre-

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2 drawn film contains approximately 81 slots per 6.4 cm; every slot is approximately 0.25 cm long.

According to the methods described in U.S. Patent 3,762,255 the slots can be made. In said US patent a method for and an apparatus for drilling through thin foil material, e.g. Plastic film described; In this process, the sheet material passes through a bore member that is flexible with a number of independent . Protrusions protruding therefrom are provided; the piercing member also includes a support member that is reticulated has outer surface. The piercing member is moved with respect to the other member, thereby causing the elastic Protrusions to follow the reticulated surface and the film selectively pierce. The piercing member can be a metal comb, a hairbrush, or a variety of metal strips parallel slots extending from one end to the other. The support member can be a wire mesh, a perforated one Metal foil, an etched metal roll or an endless belt which is moved along the piercing member.

The low-lying areas 22 (depressions) are distributed over the surface of the top and back sheets in the manner shown in Figures i through h. It can be seen that the lower film 1h and the upper film 16 contain a large number of depressions which are arranged in zigzag parallel rows (see Fig. 1) and which extend over the plane of the lower and upper film (Fig. 2 and 3). The arrangement of these depressions can be circular, elliptical, rectangular; they are to be manufactured in such a way that the upper film is not broken or cut during the manufacturing process.

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The advantages according to the invention are not achieved if, during the production of the depressions, the lower or upper film is broken, cut or melted to such an extent that the controlled passage of the liquid
is obstructed to the suction pad. If one of the foils is cut or broken during the production of the depressions, it is evident that the liquid will pass through this damage if the absorbent pad is unsaturated; is this

Suction pads saturated, or even only partially saturated, like this
it is evident that through these inlet openings the liquid exits through the upper sheet when the upper sheet
The foil is in contact with the child's skin.

Based on these considerations and in view of the ease of manufacture, we have found that the preferred form of Wells is circular (see Figures 1 to 4).

The depressions can be in the lower and upper foil
different types can be produced. With the preferred
Method uses a roller that can be heated and has a number of tips protruding from it. The tips, which have smooth, round end points, can be applied at desired intervals on the roller, so that
the desired number of indentations on the diaper liner
can be attached. The wells are preferred
applied after the tube-like openings on the diaper liner; this operation can be carried out by bringing the diaper liner with the tubular openings into contact with the heated roller. In this technique, the diaper insert is supported on an elastic pressure member, such as an endless conveyor belt or an elastic pressure roller. How deep that

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Depression can be controlled by limiting the depth to which the specimens indent the film. If if desired, portions of the top and bottom sheets can be left untreated, i.e., without dimples. This can be done, for example, by an approximate 2.54 cm wide strip located on the periphery of the lower and upper sheets. Because every slide or any film is made of thermoplastic material, the heat and pressure applied must be strictly controlled, to prevent the material from penetrating. The required The amount of heat should be enough to soften the film and the pressure required to soften the film plastically deform according to the contour of the specimen. The exact conditions regarding heat and pressure depend among other things the length of time the film is in contact with the roller; also on the thickness of the absorbent pad, etc. Since the If correct conditions can easily be determined by a person skilled in the art, it does not seem necessary to further the conditions describe in detail.

3 and 4 it can be seen that the depressions 22 extend over the surface of the lower sheet Ik and the upper sheet; it can also be seen that the absorbent material 12a is in a compressed state immediately above or below each well. At the point where a recess is formed over part of the slot 18, the slot is more open than corresponding slots which are further away from the recesses 22. The slots between corresponding indentations are much more open than would be the case if there were no indentations. We attribute this to the fact that under the action of the pressure exerted by the depressions on the surface of the upper and lower

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Exercise foil, the slits are slightly opened by the stretching of the foil. Parts of the compressed absorbent pad are included connected to these opened slots; Because of this connection, a suction effect (wieking) is created to a previously unknown extent achieved. In fact, in most cases the suction (wicking) occurs instantly. As the liquid does is conveyed to the suction pad 12, the suction pad sucks the liquid up to partial or complete saturation. As can be seen from Fig. 4, the compressed material 12a expands and pushes the indentations 22 outward, closer to the plane of the lower and upper sheets. This process is used to to close the previously opened slots, being the main tightness the liquid is retained in the absorbent pad.

This advantageously achieves maximum wicking and absorption during the critical period when excessive occurs in liquid; the backflow of the liquid from the suction pad through the same slit opening is thanks to the combination the valve effect of the slot and the recess is significantly reduced.

The wells can be on the absorbent device in different Patterns are attached. The pattern can be diamond-shaped, curvilinear; a herringbone pattern also comes in Question. The preferred pattern consists mainly of a system of zigzag rows arranged in parallel on the Surface of the upper slide. The number of depressions per 6.4 cm of the absorbent pad can be relatively wide Range can be varied.

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The advantages and wicking characteristics of the combination recess-slot are described in detail in the application by Theodore Fredrick Kozak ("Absorbent Single Use Disposable Item, "Serial No. 312,131, filed December 4, 1972 and to an assignee assigned). Therein the range of the slot size, the size of the recess and the population density are disclosed. The principal difference between the absorbent article disclosed there and the diaper liners is that Both sides of the diaper insert, i.e. the upper and lower film, are provided with slits and depressions, which makes it quick Absorption on both sides of the diaper insert is possible. As disclosed and demonstrated in the aforementioned application progress has been noted, if only one deepening per 6.4 cm of the absorbent pad were used (the recess is approximately 0.12 cm in diameter). Good results is obtained if 100 depressions are used per 6.4 cm of the absorbent pad (diameter of the depression 0.12 cm). It is

It is clear that the number of depressions per: 6.4 cm of the absorbent pad depends on the size of the depression. In general, the total area occupied by the depressions should not take up more than 20 % of the area of the absorbent material. Excellent results are obtained when the total area of the wells is between 4 and 12 $ of the area of the absorbent material. Preferably there are about 3 to 25 depressions per 6.4 cm of absorbent material (0.54 cm diameter); ideally, however, there are between 6 and 15 depressions per 6.4 cm of the absorbent pad.

Generally, the diameter of the recess will range between 0.063 and 0.63 cm. From the point of view of functioning

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and from an aesthetic point of view, a diameter between 0.19 cm and 0.38 cm is preferred for the recess.

In another, less preferred embodiment, the depressions are provided with the diaper insert shown in FIG tied together; there the slots 18 are straight and in parallon Arranged in rows.

The diaper liner can be made by a number of processes will. In a preferred manufacturing technique, a thin film of thermoplastic material such as a Ethylenäthylacrylat film of the desired thickness the procedure described earlier. After the slit, the diaper insert is more or less built up according to conventional manufacturing methods. Pieces of the same size the top and bottom sheets are trimmed; these correspond to the desired size of the diaper insert. Corresponding The size can be varied according to the intended use; a rectangular diaper insert can, for example, have a width of 25 cm to 29 cm and have a length of 64 cm to 115 cm.

The top and bottom sheets are placed on top of each other, with in the center of the foils the absorbent pad is sandwiched between them. The absorbent pad should be somewhat lengthwise and widthwise be smaller than the upper and lower foil, around the upper foil with the lower foil along their periphery! associate to be able to. A protrusion of about 1.25 cm on each side should suffice. It is convenient to have the kantan hot with each other stick together. The hot gluing can also be used to trim the edges at the same time to remove excess Edging material from the diaper and an attractive shape

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to reach the diaper.

If desired, the absorbent pad can be in the shape of an hourglass to have. In this case, and doing the manufacture to make it easier, only the absorbent pad shows the shape of an hourglass. The upper and bottom sheet can be rectangular to facilitate hot gluing of the edges.

From Fig. 6 it can be seen that the suction pad 12 has the shape of an hourglass; it is sandwiched between the top sheet 1h and the bottom sheet 16. It will be noted that the bottom and top sheets are essentially rectangular, while the absorbent pad 12 is in the shape of an hourglass. This shape was chosen only to make it easier to manufacture; Obviously, the upper and lower sheets can also have the shape of an hourglass, corresponding to the shape of the absorbent pad 12.

The diaper insert according to the invention can be used in connection with ordinary diapers for single or multiple use. Usually the liner is in the center of the diaper as shown in Figure 7; the diaper liner 10 is on the diaper 2k on the side that is normally in contact with the child's skin. The diaper 24 shown in Figure 7 is of the drop type of diaper having a 'wing' pattern. This type of folding allows the diaper to be used without holding devices, because the insert can be held in its correct position by the edges which are formed by the wing-like fold. Other types of design may require attaching means such as adhesive tape to

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prevent the insert from slipping during use. These types of holding devices are well known and therefore will be they are not described in detail.

When positioned correctly on the diaper, the structure of the insert allows the liquid to be absorbed quickly through the upper slide. However, if the hydration is too abundant, some fluids may appear around the body Insert iierum between the lower film of the insert and the absorbent surface of the conventional diaper flows. Since the lower film of the insert can also absorb liquid, some liquid gets into the insert via the lower film, whereby the passage of excess fluid into the diaper is prevented.

Surprisingly, it was found that the combination of diaper insert and the diaper absorbs more urine overall than if the absorbent material contained in the diaper liner were to the absorbent material would have been added to the diaper and formed part of the diaper. In other words, the absorbency is larger when the diaper insert and diaper are used according to the invention, in contrast to the use of the diaper without a diaper insert, but with the combined amount of absorbent material of the simple diaper and the diaper insert.

The combination of slot and recess is the reason why the liquid is easily absorbed and in the already described Kind is retained by the deposit. If the deposit is saturated or only partially saturated, so the consumer only has to replace the insert, while the simple diaper can still be used. This means

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of course time and labor savings, what a practical one Is highly desirable from a point of view.

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Claims (11)

- 20 claims (T) A diaper insert, characterized in that this least? contains an absorbent pad that is placed between a liquid-impermeable, hydrophobic lower film and a liquid-impermeable, hydrophobic upper film is mounted, each of these films has a plurality of tubular openings that tube-like openings are essentially closable to prevent the return flow of the suction pad through the röhrenar term Openings to slow down absorbed liquid, a system of depressions that appear on the top slide and on the The bottom sheet is attached with at least one depression per 6.4 cm "of the absorbent pad. 2. A diaper liner according to claim 1, characterized in that the plurality of tubular openings are substantially parallel straight slots are arranged in longitudinal rows each slot is inclined at an angle from the longitudinal axis of the row and is arranged so that the end points of each slot on a line substantially between the endpoints of corresponding slots of adjacent ones Lie in their own right. 3. A diaper liner according to claim 2, characterized in that each slot is between 0.17 cm and 0.5 cm long and the slots on the top sheet and the bottom sheet in a number between 30 to 150 pieces per 6.4 cm of the top slide and bottom slide are present. 509881/0395 4. A diaper liner according to claim 1, characterized in that the depressions on the upper film and the lower Slide in a number between 1 to 100 wells per 6.4 cm of the suction pad are present. 5. A diaper liner according to claim 1, characterized in that the depressions on the upper sheet and the lower Foil in a number between 5 to 25 depressions per 6.4 cnf of the absorbent pad. 6. A diaper liner according to claim 1, characterized in that the depressions & ui of the upper film and the lower film are present in a number between 6 to 15 depressions per 6.4 cm of the absorbent pad. 7. A diaper liner according to claim 1, characterized in that the depressions have a circular shape with a Diameter from 0.06 cm to 0.6 cm. 8. A diaper liner according to claim i, characterized in that the top sheet and the bottom sheet are each 0.5 to 2.0 mm thick, have substantially the same dimensions x are at least partially around their periphery are glued together to form a complete structure that substantially encloses the absorbent pad and this like a sandwich between the top sheet and the bottom sheet. 9. A diaper liner according to claim 8, characterized in that the top sheet and the bottom sheet of ethylene ethyl acrylate getting produced. 509881/0395 10. A diaper liner according to claim 1, characterized in that that this has a rectangular shape. 11. A diaper liner according to claim 1, characterized in that that the absorbent pad has a contour-shaped outline. 509881/0395