JP3144514B2 - Absorbent product and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an absorbent product such as a diaper for children or adults, in particular in the form of pants, ie a tapeless type, and to a method for producing such an absorbent product. About.

[0002]

2. Description of the Related Art Absorbent products, such as diapers for children or adults, are generally separated on both sides of the waist and can be deployed flat, and the back waist and the front waist can be detachably connected with tape when worn. And a tapeless type in the form of pants having a waist hole and two leg holes. In either form,
A back sheet made of a liquid-impermeable material and a top sheet made of a liquid-permeable, non-hydrophilic material placed inside the sheet are overlapped, and a body containing an absorber is partially expanded and contracted between them. It has a structure in which a waist portion and a leg hole portion are formed. Of these, the tapeless type absorbent products are particularly suitable for infants who can walk, because of their high stability when attached and the ability to be attached and detached while standing. Widespread.

[0003] A conventional tapeless type absorbent product generally has an absorbent material between a liquid-permeable top sheet and a liquid-impermeable back sheet as disclosed in Japanese Patent Application Laid-Open No. 3-82467. It has a structure in which a top sheet and a back sheet are thermocompression-bonded around the body.

[0004] In the absorbent product having such a structure, basically, an absorbent is placed on a top sheet, and the absorbent is placed outside at a central portion (a portion to be a crotch) of the absorbent. It is usually manufactured through a process in which the back sheet is folded into two and a back sheet is arranged on the outer side thereof, and then thermocompression-bonded at both sides and a crotch portion (see, for example, JP-A-3-123551).

[0005]

SUMMARY OF THE INVENTION It has been recognized that such conventional tapeless absorbent products cannot meet various demands which differ depending on the use or use form. Taking a disposable diaper as an example, the part where it is desired to have the largest absorption capacity is different between men's and women's, and in order to cope with this requirement, as an absorber, the front side of the crotch is sandwiched. It is necessary to use a member having a different absorbing capacity, that is, an amount of the absorbing material, between the member located and the portion located on the rear side.

However, absorbers having different amounts of absorbent material on the front side and the rear side naturally have different thicknesses and hardnesses on the front and rear sides. When such an absorbent body is bent into two at its central portion, It becomes difficult to perform bending at the correct position. If the absorber is not bent at the correct position, the bent position of the top sheet overlaid on it will also be out of order, and in this state, the top sheet and the thermo-compressed part will be displaced, especially at the waist, Lose commercial value.

In order to prevent such defective products from being produced, it is necessary to accurately position the overlapping portions when the top sheet is bent.
It is not easy for an industrial-scale manufacturing apparatus to accurately hold such a flexible material at a predetermined position, which causes a rise in equipment costs and a decrease in productivity.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems caused by folding an absorber into two parts in a conventional tapeless absorbent product, and to easily cope with various usage forms. It is to provide a tapeless type absorbent product which can be used.

[0009] Another object of the present invention is to provide a method of making such an improved absorbent product.

[0010]

According to the present invention, there is provided a body having a waist hole and two leg holes, an annular elastic waist along the waist hole,
An absorbent product comprising: a leg gather provided along a peripheral edge of the leg hole, wherein the main body includes a front body and a rear body mutually connected at both sides and a crotch part; Each of the front and back bodies is shaped like a crotch
With tabs formed and interconnected by this tab
A back sheet, a top sheet disposed inside the back sheet, and an absorber disposed between the back sheet and the top sheet .
At least one of a top sheet, a back sheet, and an absorber
One is provided with an absorbent product, wherein the product is made of a material different from that of the back body .

That is, the tapeless absorbent article according to the present invention is configured such that the front body and the rear body have a structure independent of each other by a combination of desired materials. Therefore, an absorbent product can be obtained which can freely cope with a use form in which different functions are required on the front side and the rear side.

When the absorbent product of the present invention is used as, for example, a diaper for infants who often take a prone position, an absorbent having a very large absorbing capacity such as pulp is used in the front body. In the back body, a thin and large-area absorber is used. This makes it possible to share the urine absorption capacity on the front side of the absorbent product and the stool processing capacity on the rear side.

As a top sheet, a bulky and fine mesh sheet made of a hydrophobic material subjected to a hydrophilic treatment is used in the front body, and a hydrophilic and coarse mesh sheet is used in the rear view. The ability to absorb urine and the ability to treat stool as described in can be maximized.

Further, by using a highly water-resistant film for the front body and a highly breathable film for the back body, it is possible to remarkably improve the usability when worn. Alternatively, by constituting the back sheet from films having different colors or patterns between the front body and the back body, it is easy to visually identify the front and rear of the absorbent product.

Further, according to the present invention, there is provided a main body having a waist hole and two leg holes, wherein an annular elastic waist portion is provided along the waist hole, and a main body provided along a peripheral edge of the leg hole. A method of manufacturing an absorbent product having leg gathers, comprising: a first step of forming a front body comprising a topsheet, an absorbent body, and a backsheet; and a method comprising the topsheet, an absorbent body, and a backsheet. A method of producing a back body, and a third step of superimposing said front body and said back body on each other and interconnecting each side and crotch. Is provided.

Prior to the third step, an elastic body serving as an elastic waist portion is formed along the edges of the front and back waist holes, and a leg gather is formed along the edges of the leg holes. A step of attaching each elastic body can be added.

Further, according to the present invention, there is provided a main body having a waist hole and two leg holes, wherein an annular elastic waist portion is provided along the waist hole, and a main body provided along a peripheral edge of the leg hole. A method of manufacturing an absorbent product having leg gathers, the absorbent product being disposed at a predetermined interval between a first continuous web and a second continuous web running in a longitudinal direction. A first step of forming one assembly and an absorber arranged at predetermined intervals between a third continuous web and a fourth continuous web running in the longitudinal direction to form a second assembly. A second step, the first assembly and the second
A third step in which the first assembly and the second assembly are thermocompression-bonded at both sides and a crotch portion while running the assemblies in the same direction.
The first, second, and third portions are thermocompressed in the third step.
A fourth step of cutting the third and fourth continuous webs;
There is provided a method comprising:

One of the important advantages of the method of the present invention is that the foresight and backsight are made in separate steps and then joined at both sides and crotch, so that the topsheet, backsheet and There is no need for a step of bending the member provided with the absorber into two at the crotch. Therefore, troublesome positioning associated with the bending is not required, and the efficiency of the process can be improved and the incidence of defective products can be reduced.

An embodiment of the present invention will be described below with reference to the drawings.

[0020]

1 to 3 show an example of a tapeless absorbent product constructed according to the present invention. In the figure, a main body denoted by reference numeral 1 is composed of a front body 1A and a back body 1B, and both are connected by a suitable means such as thermocompression bonding at a connecting portion 2a on both sides and a connecting portion 2b on a crotch portion. ing. A waist hole 3 and two leg holes 4 are formed in the main body 1, and a waist gather 5 made of an annular elastic sheet is formed along the periphery of the waist hole 3, and along the periphery of each leg hole 4. Each leg gather 6 is provided.

As shown in FIG. 2, the front body 1A and the back body 1B are made of a liquid-permeable and non-hydrophilic sheet material, for example, a top sheet 11 made of a nonwoven fabric, and a liquid-impermeable back sheet made of a sheet material. 12 and an absorber 13 disposed between the two.

What is important here is that the topsheet 11,
Each of the back sheet 12 and the absorber 13 has a front body 1
That is, it is divided at the boundary between A and the back body 1B and becomes discontinuous. That is, the front body 1A and the back body 1B are independent of each other, and are integrated only by being connected by the connecting portions 2a and 2b.

In the absorbent product of the present invention thus configured, the main body 1 has a structure in which the front body 1A and the back body 1B, which are independent of each other, are connected by the connecting parts 2a and 2b. Therefore, between the front body 1A and the back body 1B,
At least one of the top sheet 11, the back sheet 12, and the absorber 13 constituting these can be made of different materials. In other words, the front body 1A and the back body 1B can have different functions.

For example, regarding the absorber 13, an absorber having a very large absorption capacity, which is a combination of pulp and superabsorbent (SAP), is used for the front body 1A and thin and large in area for the back body 1B. By using the absorber, it becomes possible to share urine absorption capacity and stool processing capacity.

As the top sheet 11, a front body 1A
Use a bulky and fine mesh sheet made of a hydrophobic material that has been subjected to hydrophilic treatment, and use a hydrophilic and coarse mesh sheet for the rear view 1B. The ability can be maximized.

FIGS. 4 to 6 show an absorbent product according to a second embodiment of the present invention. In the absorbent product of this example, the configuration of the front body 11 is the same as that shown in FIGS. 1 to 3, but the rear body 12 includes an elastic composite sheet 21 described later,
It consists of an absorption pad 22 disposed inside. As shown in FIG. 5, the absorbent pad 22 has an absorbent core 24 inside a bag-shaped cover 23 whose periphery is sealed.
, And is joined to the front body 1A together with the composite sheet 21 by only one side by means of thermocompression bonding or the like. In FIGS. 4 to 6, FIGS.
Are denoted by the same reference numerals, and detailed description thereof will be omitted.

The elastic composite sheet 21 used to form the back body 1B is made of synthetic rubber, as shown in FIG.
Polyurethane, styrene-butadiene block polymers, such as polyolefin elastomer, on one or both sides of the binding by thermocompression bonding or the like are composed of a material capable film or nonwoven elastic sheet 31 (both sides in the illustrated example), the skin The nonwoven fabrics 32 and 33 having excellent feeling to the user are overlapped, and these are joined in a linear connection portion 3 arranged in parallel with each other.
4 and has a structure joined by thermocompression bonding. Preferably, a channel-like space 35 is formed between the elastic sheet 31 and the nonwoven fabrics 32 and 33 between the joining portions 34 and 34 adjacent to each other.

An absorbent product having such a structure has a back body 1
Since B is composed of the composite sheet 21 having excellent elasticity, it can be easily attached and detached, and is excellent in following the shape or movement of the body in a worn state.
Gives a very good feeling of use.

FIGS. 8 to 11 show an absorbent product according to a third embodiment of the present invention. In the absorbent product of this example, side gathers 41a made of two laminated elastic composite sheets are connected to both sides of the front body 1A.
B is also connected to a side gather 41b made of two layers of stretchable composite sheets, and the connection at both sides of the front body 1A and the back body 1B is performed at the side edges of the side gathers 41a and 41b.

The waist gather 5 is arranged along the edge of the waist hole 3 in a state of being sandwiched between the top sheet 11 and the back sheet 12, while the leg gathers 6 are provided on the side gathers 41a and 41b. Installed.

The side gathers 41a and 41b assist the elasticity of the elastic waist provided along the waist hole by their excellent elasticity, thereby making it easier to attach and detach, and to provide a fit when worn. Helps improve sex.

FIG. 12 and FIG. 13 show a fourth embodiment of the absorbent product of the present invention. In this example, 1
As A, an assembly composed of a back sheet 11, a top sheet 12, an absorber 13, a waist gather 5, and a leg gather 6 and having the same configuration as that of the first embodiment shown in FIG. 3 is used. Has cuff barriers 51a and 51b added to this configuration. The cuff barriers 51a and 51b can be formed of, for example, an elastic composite sheet as shown in FIG. Each of the cuff barriers 51a and 51b extends from both side edges of the back view 1B toward the center to cover the top sheet 12 of the back view 1B, but a part thereof is cut off to form the opening 52. I have.

Therefore, the top sheet 12 of the back view 1B
Opening 5 between the cuff barriers 51a and 51b.
A pocket for accommodating the stool, which is connected to the outside through 2, is formed.

FIGS. 14 to 16 show a fifth embodiment of the absorbent product of the present invention. In this example, the front view 1A and the back view 1B are the backsheet 11, the topsheet 1
2, an absorber 13, a waist gather 5, and a leg gather 6, for example, an assembly having the same structure as that of the first embodiment shown in FIG. A pad 60 is attached. The absorbent pad 60 is provided inside a rectangular bag-shaped cover 61 made of a liquid-permeable sheet.
2 and is connected to the joint between the front view 1A and the rear view 1B only by one side edge of the cover 61.

In the state shown in FIG.
Is positioned so as to overlap with the top sheet on the 1A side when viewed from the front, and this state exhibits excellent absorption performance as a diaper for boys, for example. In addition, in a state where the absorbent pad 60 is tilted to the side 1B at the rear view, the absorbent pad 60 is optimal for a diaper for girls, for example.

As described above, the most significant feature of the present invention is that the main body constituting the absorbent product connects the front and rear views each made separately to each other at both sides and the crotch. It is in. In general, in the absorbent product, the crotch is the place where the excrement is most concentrated in normal use, and the absorption capacity and liquid tightness of this part are one of the important factors that determine the performance of the absorbent product It is. In the present invention, the junction between the foresight and the foresight is located at the crotch, so that the liquid tightness of the connection at this part is important.

If a material that can be easily bonded by thermocompression bonding or the like is used as the material of the top sheet and the back sheet, a product that does not hinder practical use can be obtained by bonding using ordinary bonding means. However, when using a material that does not provide sufficient liquid tightness with ordinary bonding means, or in the case of an absorbent product used for an application where extremely high liquid tightness is desired,
An ingenuity is required for the connection in the crotch part.

FIG. 17 shows an example of the structure of the connecting portion for obtaining a very high liquid tightness. In FIG. 17, the top sheet 11 and the back sheet 12 of the front view 1A are shown.
Are overlapped with each other at the crotch side end to form a tab 71A.
1 and the backsheet 12 are also overlapped with each other at the crotch side end to form a tab 71B. The tabs 71A and 71B are abutted against each other, an adhesive 72 such as a hot melt is applied to the opposing surfaces, and then joined by a linear joining line 73 by thermocompression bonding.

According to such a configuration, high liquid tightness is maintained even at the boundary between the foresight 1A and the foresight 1B, and no liquid leakage occurs in any use mode.

As shown in FIG. 18, a tape-like reinforcing member 74 extends along the boundary between the front view 1A and the rear view 1B.
By attaching, it is possible to improve not only the liquid leakage prevention property but also the strength against tearing.

In the absorbent product of the present invention, the combination of materials or structures for sharing functions between the front body 1A and the back body 1B used in each of the above-described embodiments is merely an example. It can be freely selected according to different requirements depending on the form. Further, by forming the back sheet from films having different colors or patterns in the front body and the back body, it is possible to obtain an effect that it is easy to visually identify the front and rear of the absorbent product.

Next, an example of a method for producing an absorbent product having the structure shown in FIGS. 1 to 3 according to the present invention will be described with reference to FIG. In this example, the first step of forming the front body and the second step of forming the back body proceed simultaneously, and in the subsequent third step, the separately formed front and back bodies are combined. Is done.

First, the first step of forming the front body will be described.
In FIG. 19, a first sheet 101 in the form of a continuous web is drawn from a roll 102 at a predetermined constant speed. Further, a carrier sheet 104 is continuously pulled out from the roll 103, and an absorbent material such as pulp is successively provided thereon at a predetermined interval by a pulp former 105 as an absorber (not shown) having a predetermined shape. And then superimposed on the first sheet 101 to form the first assembly 100.

Next, the second sheet drawn from the roll 106
Sheet 107 is bonded to the elastic body 109 for leg gathers pulled out of the roll 108 by means (not shown), and then stacked on the first sheet 101 and the absorber, and further, the waist pulled out of the roll 110 The gathers 111 are stacked below the first sheet 101 and sent to the next stage.

On the other hand, in the same step as the above-mentioned step, a second step for making a guardian is performed. That is, the second sheet 201 in the form of a continuous web is drawn from the roll 202 at a predetermined constant speed. Also, the carrier sheet 204 is continuously pulled out from the roll 203, and on top of that,
An absorbent material, such as pulp, may be
Then, they are sequentially arranged at predetermined intervals as absorbers (not shown) having a predetermined shape, and then are stacked on the second sheet 201 to form the second assembly 200.

Next, the second sheet drawn from the roll 206
Sheet 207 is bonded to the elastic body 209 for leg gathers pulled out of the roll 208 by means not shown, and then stacked on the second sheet 201 and the absorber, and further, the waist pulled out of the roll 210 The gathers 211 are stacked and sent to the next stage. However, the vertical relationship between the second sheet 201, the carrier sheet 204, the absorber, and the waist gather 211 is opposite to the vertical relationship of each element with respect to the first sheet 101.

In this example, the first sheet 101 is a non-woven fabric serving as a top sheet, and the second sheet 201 is a liquid impermeable film serving as a back sheet.

The first assembly 100 and the second assembly 200 obtained through the above steps are superimposed on each other so that the respective absorbers are on the inside, and the next ultrasonic sealing device 301 is used to seal both products. The thermocompression bonding is performed at the sides and the crotch, and the front view and the back view are joined. At this time, it is important to accurately align the first and second assemblies 100 and 200 with each other. This alignment can be easily realized by synchronizing the transport speeds of the assemblies 100 and 200 with each other.

After the joining is completed, cutting for forming a leg hole is performed in the next round cutter 302, and then separated into individual products by the end cutter 303.

In the case of manufacturing an absorbent product having a structure in which the front body and the back body are connected by elastic side bands 7 on both sides thereof as shown in FIG.
On both sides of the sheets 31 and 32, elastic bands which are to be side bands are connected in advance by thermocompression bonding or the like, and the ends of the bands are connected to each other by the ultrasonic sealing device 301.

Alternatively, both ends of the elastic waist portion 5 may be extended, and this extended portion may be used as the side band 7.

[0052]

As described above, in the absorbent product of the present invention, the top sheet, the back sheet, and the absorber are separate for the front body and the back body, and the front body and the back body are separated. A structure in which both sides and the crotch are connected by a suitable connecting means such as thermocompression bonding is employed. Therefore, it is possible to freely cope with a usage form in which different functions are required on the front side and the rear side.

Further, according to the manufacturing method of the present invention, the foresight and the foresight are formed separately from each other, and finally combined into one product. Therefore, unlike the conventional method, there is no step of bending the assembly in which the absorber is combined with the top sheet at the crotch part, and troublesome positioning of both sides in the bending step is unnecessary. Therefore, not only process control becomes easy,
The defective rate can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an absorbent product according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the absorbent product of FIG.

FIG. 3 is a developed perspective plan view of the absorbent product of FIG. 1;

FIG. 4 is a partially cutaway perspective view showing an absorbent product according to a second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of the absorbent product of FIG. 4;

FIG. 6 is a developed perspective plan view of the absorbent product of FIG. 4;

FIG. 7 is a longitudinal sectional view of a part of a stretchable composite sheet suitable for use in the absorbent product of the present invention.

FIG. 8 is a partially cutaway perspective view showing an absorbent product according to a third embodiment of the present invention.

9 is a longitudinal sectional view of the absorbent product of FIG.

FIG. 10 is a developed perspective plan view of the absorbent product of FIG. 8;

FIG. 11 is an enlarged sectional view taken along line AA of FIG. 10;

FIG. 12 is a developed perspective plan view of an absorbent product according to a fourth embodiment of the present invention.

FIG. 13 is an enlarged sectional view taken along line BB of FIG. 12;

FIG. 14 is a partially cutaway perspective view showing an absorbent product according to a fifth embodiment of the present invention.

FIG. 15 is a longitudinal sectional view of the absorbent product of FIG. 14;

FIG. 16 is a developed perspective plan view of the absorbent product of FIG. 14;

FIG. 17 is a partially cutaway perspective view showing a preferred form of a joint between a front view and a back view in the absorbent product of the present invention.

FIG. 18 is a partially cutaway perspective view showing another preferred form of the joint between the front view and the back view of the absorbent product of the present invention.

FIG. 19 is a system diagram showing an example of a process of manufacturing an absorbent product according to the first embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 1A Front body 1B Back body 2a, 2b Connection part 3 West hole 4 Leg hole 5 Elastic waist part 6 Leg gather 7 Side band 11 Top sheet 12 Back sheet 13 Absorbent 21 Elastic composite sheet 22 Absorbing pad 23 Cover 24 Absorbent cores 51a, 51b Cuff barrier 60 Absorbing pad 61 Bag-shaped cover 62 Absorber 71A, 71B Tab 72 Adhesive 73 Reinforcement member 100 First assembly 200 Second assembly 101, 201 First sheet 104, 104 Carrier sheet 105 , 205 Pulp former 107, 207 Second sheet 109, 209 Elastic body 301 Ultrasonic sealing device 302 Round cutter 303 End cutter

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A61F 13/49-13/84

Claims (14)

(57) [Claims] 1. An absorber comprising: a main body having a waist hole and two leg holes; an elastic waist portion having an annular shape along the waist hole; and a leg gather provided along a peripheral edge of the leg hole. The product, wherein the main body is composed of a front body and a back body mutually connected at both sides and a crotch part, and each of the front body and the back body has a tab formed on the crotch part. , Mutual in this tab
Together are coupled to, contact comprises a backsheet, a topsheet disposed on the inside, an absorber and said disposed between the backsheet and said topsheet
And the front body top sheet, back sheet, and absorber
At least one of which is different from the back body
An absorbent product characterized by being made of a material . 2. The absorbent product according to claim 1 , wherein the tabs are connected to each other via a hot melt adhesive. To wherein the front body and the back body are tabs formed on each end of the crotch portion, each tab is bonded by means of the hot melt adhesive, further wherein the back body and the back body The absorbent product according to any one of claims 1 and 2, wherein a tape-shaped reinforcing member is attached along a boundary line between the crotch portions. 4. The backsheet of the back body is formed of a liquid-impermeable stretchable composite sheet .
4. The absorbent product according to any one of 3 . Wherein said stretchable composite sheet, superposed film or nonwoven nonwoven on at least one surface of the elastic sheet, bonded by thermocompression bonding at these arranged parallel to each other a linear coupling portion The absorbent product according to claim 4 , which is constituted by a stretchable composite sheet having a structure. Wherein said front body and the back body is at its both sides unit, absorbent body according to any one of claims 1 to 5 connected to each other via a sideband of resilient sheet Product. 7. The rear body includes a cuff barrier attached to form a space between the back body and the top sheet, and the cuff barrier has an opening for transferring excrement to the space. The absorbent product according to any one of claims 1 to 6 . 8. An absorbent pad disposed between the front body and the rear body, the absorbent pad being connected to the crotch joint at only one end thereof, and connected to the front body or the rear body. the absorbent product according to any one of claims 1 to 7, the are <br/> positioned to overlap the top sheet. 9. A main body having a waist hole and two leg holes, wherein an annular elastic waist portion is provided along the waist hole, and a leg gather provided along a periphery of the leg hole. a method of manufacturing an absorbent product with the topsheet, absorbent body, and a first step of making a pre <br/> body consisting of the backsheet, topsheet, absorbent core, and after consisting backsheet how to a second step of making the body, the front body and overlaid the back body together, characterized in that a third step of connecting together at both sides portion and the crotch portion of each. 10. An elastic body serving as an elastic waist portion along an edge of a waist hole of the front body and the back body, and a leg along an edge of a leg hole prior to the third step. The method according to claim 9 , further comprising attaching elastic bodies to be gathers. Wherein said third step, according to claim 10 carried out in a stretched state to the front body and the said leg gathers each attached to the back body elastic body and an elastic body that becomes the waist gather the method of. 12. A body having a waist hole and two leg holes, and having a ring-shaped elastic waist portion provided along the waist hole, and a leg gather provided along a peripheral edge of the leg hole. A method of manufacturing an absorbent product comprising a first continuous web and a second continuous web running in a longitudinal direction, wherein an absorber is arranged at a predetermined interval to form a first assembly. A second step of arranging absorbers at predetermined intervals between a third continuous web and a fourth continuous web running in the longitudinal direction to form a second assembly; The first assembly and the second assembly are overlapped while running in the same direction, and the first assembly and the second assembly are thermocompression-bonded at both sides and the crotch portion. A third step, and the first, second, and
Method characterized by comprising <br/> a fourth step of cutting the third and fourth continuous web. 13. The method according to claim 1, wherein the first step is performed prior to the third step.
And between the second continuous web and the third and fourth webs
A step of attaching an elastic body serving as a stretchable waist along the edge of the waist hole and an elastic body serving as a leg gather along the edge of the leg hole. 13. The method according to 12 . 14. The third step is, between the first assembly and the second assembly, according to claim 1 including an operation of placing an elastic sheet comprising a sideband
3. The method according to 3 .