DE3039847A1 - FASTENER WITH A TWO-LAYER ABSORPTION SYSTEM - Google Patents

Description

description

The invention relates to a new sanitary napkin (sanitary napkin), it relates to in particular a sanitary napkin with layers of materials with different absorbency or absorbency.

A sanitary napkin or sanitary napkin should have several characteristics. It must be comfortable, it must have a high absorbency (absorption capacity) have, must drain liquid quickly from the surface adjacent to the support and be relatively cheap to manufacture.

Wood pulp or cellulose fibers or other similar natural cellulose fiber systems have long been used as the primary absorbent component of these napkins. A wood pulp or. Cellulose fluff is soft, elastic, absorbent and cheap.

One of the difficulties encountered when using wood pulp alone as a Absorbent for the menstrual fluid occurs, is that it has no permeability in a preferred direction, so that there are higher concentrations of exudate in the areas closest to immediate contact. The result is one Wet upholstery or pillow surface that tends to leak prematurely. These permeability problems are even more pronounced, when the cushion (pillow) gets wetter.

These problems have already been recognized and attempts have been made to find suitable ones Absorbent composite systems using wood pulp (cellulose) or the like as one of the absorbent layers to develop. The other absorbent or absorbent layer,

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which is usually placed on top of it, was selected on the It is based on the theory that it is desirable for the liquid to cross the surface of the upper absorbent layer happened asap. In some cases, this can be achieved by letting the top surface of the upper absorbent resp. absorbent layer 'is made "hydrophobic" and / or by that the more viscous parts of the Kenstrual Fluid in the upper layer are selectively absorbed, at least hypothetically the aqueous portion of the menstrual fluid is prevented from the flaky layer (fluff layer) to. happen. It was too theoretically assumed that absorption systems in which two units with a high absorbency or a high absorbency used in successive layers would be particularly advantageous.

An example of such absorbent or absorbent composite systems is given in US Pat. No. 3,371,667, in which a highly porous elastic element is described which serves to "capture highly viscous mucous membrane and gelatin constituents of body fluids". This patent specifies that the upper layer (cover layer) described in this way would allow the less viscous components to pass through. Suitable fibers that have been contemplated are rayon fibers which have been made relatively hydrophobic on the surface, but in which the inner part of the fibrous web has been treated with hydrophilic agents.

Another example of a composite binder is described in US Patent A-037,531, which has an outer layer made of fluff a thermomechanical pulp (flaky layer) (flaky in conjunction with a traditional fluff layer

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Layer) is used as an absorption system. Again, the principle described in this patent is the use of a "hydrophobic" fiber in the top layer.

There are already other absorbent or absorbent composite systems known, but they all obviously describe the use of a top layer (top layer), less at best is absorbent (absorbent) than the bottom layer (bottom layer) and is, in fact, poor in practical absorbency, in particular in relation to the aqueous component / »the menstrual fluid, exhibit.

The invention relates to an absorbent system for a sanitary napkin or sanitary napkin or the like with two layers, the layer closest to the wearer's body being liquid easily passes through the upper surface while maintaining good overall absorbency or good overall absorbency, while at the same time the lower surface (floor surface) of a conventional cellulose fiber mat is wetted.

It has now been found that these composite absorption systems are essential Can be improved by using a top layer (cover layer) that acts as an absorbent for all components of menstrual fluid can serve by combining high absorbency (high absorbency) with good liquid permeability properties.

The invention relates in particular to a sanitary napkin or sanitary napkin with two layers that are related to their composition are different from each other. The lower absorption layer contains

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any of the conventional cellulosic materials such as wood pulp (Pulp), while the upper layer (cover layer) made of a material with a relatively large capillary action and a there is controlled fluid retention. The bandage is made of a liquid-permeable layer that comes into contact with the body Material and a lower liquid-impermeable Layer (underlay).

When the menstrual fluid with the upper absorbent layer the composite sanitary napkin or sanitary napkin according to the invention comes into contact, it quickly passes the upper surface of the layer and spreads rapidly in the radial direction as it traverses the thickness of the first layer. During this pass it becomes a part of all components the liquid retained.

The top layer must have relatively large distances between the fibers have so that the upper layer can quickly let the liquid through. When the top layer has extremely high fluid retention the liquid runs after the upper layer is saturated with it is, between the upper layer and the cellulose fiber layer butted thereto, resulting in a problem that the liquid runs out laterally. It can also happen that in the case of a highly absorbent or highly absorbent upper layer (cover layer) the Blockage of the capillaries in this layer as a result of the high absorption prevents at least part of the flow from entering the second Absorbent layer comes into contact.

It has now been found that an upper layer (top layer) with a Capillary absorption composite value of not more than 0.5 and an equal

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weight capacity of not more than 4.6 grams of absorbed material per gram of absorbent in combination with a conventional cellulo * loose layer, e.g. from wood pulp fibers (cellulose fibers), results in a highly effective absorbent or absorbent system, in the absorption capacity of both layers is used with a high degree of efficiency, without leakage to the side or a & Surface puddle on top of each absorbent layer occurs.

The invention is described below with reference to the accompanying Drawings explained in more detail. Show:

Fig. 1 is a perspective view, partly in section, of the structure a typical feminine or sanitary napkin and

FIGS. 2 and 3 are schematic representations of the tests used for characterization of the upper absorption layer in the pad (pillow) according to the invention.

The sanitary napkin (sanitary napkin) N shown in FIG. 1 has a liquid-permeable outer shell, which the other loading ■ Completely encloses parts of the bandage. Just below the top bottom surface of the surrounding envelope is an upper absorbent Layer 2 arranged. The absorbent layer 3 made of conventional wood pulp or a similar absorbent Material is just below the top absorbent layer and on top of a liquid impervious barrier layer (Diaphragm) 4 arranged. The liquid impervious barrier layer in practice surrounds the sides of the lower absorbent Layer and can extend up to the cover part of the sides of the

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Upper absorbent layer extend. This structure has the advantage that the lateral leakage of the liquid from the cushion (pillow) is kept to a minimum. The pad (cushion) is sealed at the front and rear edges 5 and 6 in a conventional manner, for example by adhesive sealing. The seal is indicated by the two closely spaced lines inward of the edges at their respective ends. This special cushion is the strdfafros version and, as partially shown by dashed lines, it has an adhesive strip with an exposed lower adhesive surface for attachment to the undergarments. The pad shown in Fig. 1 (cushion) is the presently preferred embodiment, in which an outer liquid permeable cover of bonded polypropylene spun * ^w i ^ß disclosed in U.S. Patent 3,886,942, and a presently preferred barrier layer of 1.52 cm (0.6 mil) polypropylene is used. The presently preferred lower absorbent layer is made of pulp fluff, and the upper absorbent layer is selected based on the judgment as shown in the table below and the cost.

It is clear that the embodiment shown in Fig. 1 only is an example of a specific setup that can be chosen, and that the invention is in no way limited to this structure. For example, a sandwich type sanitary napkin can be made in which the liquid-permeable upper layer extends only to the edge of the cushion (cushion) and the liquid-impermeable lower film or barrier layer completely around the perimeter of the cushion or cushion directly on the liquid-permeable upper layer is fixed.

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* (Spunbonded polypropylene)

The composite capillary absorption value is obtained using the capillary absorption composite test. This test is carried out as follows: first, the material to be examined is placed on a Web making apparatus made for the purpose of comparison

to the production of a web with a basis weight of 40.66 g / m

(34 g / ft.) Is set. The material is punched for production a circle 3 inches in diameter. In the same way, a similar disc is made from punched out Cut out 3 inch diameter pulp fluff and placed under the experimental absorbent material for testing. The test apparatus used is shown in FIG.

The test apparatus consists of a variable speed injection pump or rate and means to keep the temperature and pressure on the sample constant. With the one used for the test The liquid is bovine blood, the hematocrit of which, i. its red blood cell content, to a value of 20 wt the solution has been discontinued. The blood is pumped past a magnetic stirrer 12 through an injection ejector 13 into the Receiving tube 14 introduced. The receiving tube 14 leads into a hollow-walled one Heat exchanger 15, which, as shown in the partial cross-section, rests on a carrier block B, which in turn rests on the sample pad 19. The colostomy bag stands over the colostomy insertion tube 21 via the pump P in fluid communication with a constant temperature bath. As shown in the drawings, leads the pump P also has a temperature regulating water flow through a water supply line 20 into the heat exchanger 15. The standpipe 22 is also in communication with the colostomy bag through the pressure pipe 24, The standpipe, in conjunction with the constant temperature bath 23, regulates both the temperature and the pressure. The sample is at a

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constant temperature of 37 C, which is body temperature is held by means of the in the constant temperature bath generated liquid flow, which is introduced through the pipe 20 into the heat exchanger 15 (wherein the liquid through the Outlet line 16 exits from the heat exchanger jacket), and also by the current which is introduced into the colostomy structure 17 through the conduit 21. The pressure is kept at 75 cm FLO and the Modified Bovine Blood Stream. will be for 90 minutes at a Maintained flow rate of 2 ml per hour. The capillary absorption composite value is calculated after the end of the test », The value is the ratio between the surface area the color stain from the bovine blood on the lower surface of the absorbent topsheet and the surface size of the color stain on the lower surface of the lower absorbent layer. The lower the value, the greater the amount of passage of the Liquid in the Z-direction and the distribution of the liquid along the lower surface of the absorbent material. It should be emphasized that the calculated value not only reflects the capillary action (capillarity) or size of the capillaries. If this were desired, would be the test is only a measure of the time that the bulk of the liquid is consumed needed to go through from one surface to another. By measuring the actual radial spread or distribution of the Liquid along the lower surface and by comparing this value with the distribution (spread) on the upper side is obtained an indication of capillarity related to absorption.

The second method that is used to characterize the upper absorption layer in the cushion (pad) according to the invention, is the controlled capacity. As used herein, the term "controlled capacity" is to be understood as meaning that the absorbent layer

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a certain but limited pumping speed or absorption capacity owns. As indicated above, it is desirable that the second absorption layer contribute significantly to the absorption process, and in order to achieve this, it is necessary to carefully control the absorbency (absorbency) of the top layer (steer). The value for the absorption capacity is determined by the capillary sorption apparatus as shown in FIG. 3. This Test is explained in more detail below with reference to the individual parts of the apparatus shown.

In general, this particular test can be called an analysis, in which the relationship between the pore volume and the capillary pressure during the absorption of a particular system is determined. The for Apparatus used to carry out this test comprises a filter funnel 35 with a flat (planar) ground Pyrex filter disc 40 medium porosity. The filter disk is 3 inches in diameter and is as described in the test above The sample prepared and cut to a 3 inch diameter is placed on the filter disc. A pipe 33 connects the funnel with a long capillary glass tube that is fixed in a horizontal position. The liquid reservoir 30 is connected to the capillary tube 31 by a three-way blocking path 32. There is one between the capillary tube 31 and the stopcock 32 Drain line 36. The capillary tube is either inside or using a. Dipstick calibrated so that the liquid volume per cm pipe can be calculated. The reservoir 30 is provided with an im

(R) Commercially available research fluid called Isotorr. This liquid has a pH of 7.4 and the surface tension of the same was adjusted to 54 dynes. After the reservoir has been filled, an uninterrupted liquid

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column from the lower surface of the filter plate into the capillary tube into it. A porous Teflon weight of about 210 g is placed on top of the sample when it rests on the sample plate, and a lid is placed on the filter funnel to prevent fluid loss to prevent. The filter funnel 35 is mounted on a graduated dipstick 34 and the funnel is closed with it closed Stopcock raised to a position of 60 cm. The stopcock is then opened to allow free flow of the liquid from the tested Allow sample into the capillary tube. The system is then allowed to equilibrate, the establishment of the equilibrium (equilibration) depends on the particular absorbent pad or pattern chosen. The cell is then lowered at predetermined intervals, whereby the equilibrium can be set in each case until the entire cavity volume of the sample has been filled, i.e. is 0 cm. At this point the sample has gone from dry to full saturation. For the purposes of the In the respective tests, the selected absorption value is the amount of liquid per gram of absorbent at a level of 30 cm is retained in the desorption cycle.

Using the test procedure described above, a A number of absorbent materials were tested and the results obtained are given in the table below.

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Tabel Characterization of the materials

material Grundge
weight in _
q / _m 2 (c, / ft. ² ) Body padding
(20 layers) 40.66
(34g / ft ^Z ) Cellulose-
fluff 38.27
(32g / ft ² ) Polyester,
3.0 denier 38.27
(32g / ft ² ) ABSORBIT,
3.3 denier 40.31
(33.7g / ft ^) ABSORBIT,
1.5 denier 39.47
(33g / ft ^Z ) Rayon,
1.5 denier 38.27 ₂ Rayon,
3 _r 0 denier 38.27 ₂ Polyester / rayon
(80 / 2O) mixture
3.0 denier 38.27 ₂

Top / bottom capacity / side-stain- capillary tension

1.07 0.77 0.06

0.78

1.14 0.28 0.05

1.54

4.6

0.6

2.8

3.0

1.4

0.4

BUCKEYE CLD 40.66
(34g / ft ² ) 0.12 7.58 AQUALON 40.66
(34g / ft ² ) 0.10 7.79 Thermomechanical
(Australian TMP)
(Pinus Radiata) 40.66 ₂ 1.39 3.40

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In the case of the one designated as "thermomechanical" in the table above Pulp is an example of that in U.S. Patent 4,047,531, which has already been discussed above Material.

AQUALON is a trademark of the Hercules company Incorporated for a material with particularly good absorbency properties or so-called superabsorbent properties (superabsorbents). The composition is that of carboxymethylated cotton waste.

BUCKEYE CLD is a trademark of Procter & Gamble and is included it is also a so-called superabsorbent material (Superabsorbent material) and it consists of carboxymethylated cellulose fibers.

ABSORBIT is a trademark of American Enka, Division of Akzona, for a cellulose mixed fuser that uses an alkali metal or Ammonium salt of a copolymer or terpolymer of acrylic acid and / or methacrylic acid.

It should be noted that "the denier is an essential Influence on the performance of the selected material seems to have. It should be noted that the ABSORBIT and Rayon samples, each with higher denier, meet the criteria of the test that however, the ABSORBIT and Rayon samples, each lower denier do not meet these criteria. It therefore appears that factors other than the choice of absorbent material also play a role in this Fulfillment of the respective test parameters which define the present invention.

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Although the invention has been preferred with reference to FIG Embodiments explained in more detail, but it is for those skilled in the art it goes without saying that it is by no means restricted to this, but that these are changed and modified in many ways can without thereby departing from the scope of the present invention.

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Empty soap

Claims (3)

Claims I. Flexible, soft sanitary napkin, characterized in that that it contains or consists of a combination of a) a liquid- or fluid-permeable upper layer, b) a first absorbent layer (2) made of a relatively thin, highly absorbent material with a high capillary action, the absorbent material having a capillary absorption composite value of has no more than 0.5 and a pumping speed (capacity) of no more than 4.6 g absorbed material / g absorbent, c) a second layer (3) made of a conventional absorbent Cellulose material, which is arranged below the first layer (2), and d) a liquid- or fluid-impermeable barrier layer (4). 2. A sanitary napkin according to claim I, characterized in that the upper layer (2) 5 to 80 wt -.% Of the total absorbent material matters. 130018/0899 TELEPHONE (Ο89) 22 28 62 TELEX O5-2Ö38O TELEGRAMS MONAPTH TELECOPER 3. A sanitary napkin according to claim 1 and / or 2, characterized in that the upper layer (2) 15 to 60 wt -.% Makes up the entire absorbent material. 130018/0898