CN1188404A - Continuous adhesive printing on a non-continuous sequence of disposable absorbent articles - Google Patents

Abstract

The present invention relates to a process for making disposable absorbent articles (10) comprising two materials (10,20) which are adhered to each other. Importantly, the process utilises continuous roll printing (30) to provide the adhesive (2) onto a discontinuous series of separated pieces (10) of a substrate.

Description

Continuous adhesive printing on a non-continuous sequence of disposable absorbent articles

The present invention relates to the process of making disposable absorbent articles such as sanitary napkins, pantiliners, menstrual pads, incontinent pads, and adult or infant diapers. In particular, the present invention relates to the process of making disposable absorbent articles having two materials bonded to each other. In particular, the process uses a continuous roll printing to print the adhesive onto a non-continuous sequence of individual individual pieces of substrate material. The application of this adhesive printing process allows the entire surface to be covered with adhesive without having to cut at the site of the adhesive when separating individual substrate materials after printing the adhesive.

Disposable absorbent articles such as sanitary napkins, pantiliners, menstrual pads, incontinent pads, and adult or baby diapers typically have adhesive on their garment-facing surfaces to allow them to adhere to the surface during use. on the user's clothing. In particular, sanitary napkins and pantiliners generally have pressure sensitive or hot melt adhesives to allow them to be attached to the wearer's panties so that the article fits and is comfortable to the wearer. These adhesives are generally covered with a release liner prior to use.

More generally, the absorbent article will have regions of adhesive to hold together the materials that ultimately make up all or part of the absorbent article. Specifically, the multilayer structure comprising the topsheet, absorbent core and backsheet of the absorbent article is usually held together by adhesives. The attachment of the topsheet, absorbent core and backsheet to each other can also be accomplished by adhesives.

Typically, these products are produced by high speed machines. The machine includes equipment for adding adhesives in a fast and efficient manner, ensuring consistent performance across a wide range of absorbent products.

A common way to provide adhesive is by slot-coating or spraying the adhesive onto a continuously conveying web of material fibers. The adhesive-covered surface of said material is joined together with other materials to form all or part of a disposable absorbent article. These adhesive application methods eliminate the need for contact between the device and the covered material while the adhesive is being applied. This is especially necessary for thermoplastic film or nonwoven materials commonly used in disposable absorbent articles, as these materials are highly heat sensitive and cannot be bonded using high melting temperature bonding methods.

Another method of applying adhesives to materials used in absorbent articles is screen printing. In the screen printing method, the adhesive is applied to a perforated rotating roll. The roller (also called the wire mesh) is in contact with the continuously fed material fibers so that the adhesive passes through the holes and onto the material. Also, only the adhesive is heated and the screen in contact with the surface to which the adhesive is applied is not heated.

Yet another method of applying the adhesive is to prime coat the adhesive on one of the materials used to manufacture the absorbent article. This operation can be done as a separate process before the material is used in an absorbent article. For example adhesive tapes or films (as used in baby diapers) have an adhesive side and an adhesive-free side. When the adhesive tape or film is rolled into a roll, the adhesive side does not stick (or at least really sticks) to the non-adhesive side very well. To use the material, unroll the roll and apply the adhesive side to the material to be attached with the adhesive tape or film.

US Patent 5,064,492 prints on a liquid impervious film a special adhesive which is said to not freeze below about 43°C (110H) in the following manner. The approach is to apply the adhesive to the film with a patterned printing roll and a chilled make-up roll or a series of such printing units if an adhesive pattern is desired. Roll the film-covered adhesive below the adhesive's setting temperature.

This method of providing a pre-cover film adds to the complexity of logistics, storage and finishing of the absorbent article, and even inadvertent heating of any part of the pre-cover roll will render the adhesive unusable (self-blocking). Difficult alignment when unrolling the film also makes it impossible to accurately position the adhesive print. Furthermore, the adhesive has to be heated repeatedly to return to the viscous state, which increases energy consumption, and there is also the possibility of the adhesive melting and passing through the underlying film material. This heating of the adhesive also degrades the quality of the adhesive because it increases the thermal cycling of the adhesive.

In a similar patent application entitled "Adhesive Printing of Disposable Absorbent Articles" an adhesive printing process is disclosed which involves applying a continuous or patterned adhesive to a continuous On the fibers of the first material, especially for continuous adhesive applied in this form, it is necessary to cut the adhesive layer to separate it into individual substrates.

Common disadvantages of all of the above adhesive application processes are that they are not adjustable, the pattern of adhesive applied is imprecise, and they essentially only provide a continuous supply of adhesive followed by the need to cut the adhesive layer. A disadvantage of an on-off system for application or spraying is that it delays system response and generally suffers from intermittent fast and slow flow of adhesive clumps. For hollow cylindrical screen printing, it is possible to engrave a pattern on the screen to obtain the adhesive pattern, but this is subject to certain restrictions, that is, the distribution of adhesive application locations (holes) on the screen needs to be fairly uniform To reduce temperature variations that ultimately lead to unstable application processes. In addition, in terms of its stability, adhesive screen printing is not possible to uniformly cover the entire surface with adhesive, which is due to the maximum pore size and the entire open area of this screen.

Even though the system in use allows intermittent application of adhesive to a continuous substrate, the operation of separating the continuous substrate into individual pieces requires a high degree of precision in the placement of the adhesive relative to the cutting machine (cutting) Otherwise, the cutting machine will cut the adhesive layer. Cutting the adhesive layer has obvious disadvantages, namely increased wear and reduced efficiency, because this practice increases the need for cleaning of the cutting equipment.

Applicants have now found a process for applying adhesive to an area of a disposable absorbent article which extends at least to the periphery of the substrate without having to cut the adhesive. The process allows the entire surface to be covered with adhesive and is generally more stable and precise than existing treatments. The process of the present invention reduces downtime during production compared to conventional adhesive application methods.

It is therefore an object of the process of the present invention to provide an absorbent article having an adhesive region which joins two materials within the absorbent article. In particular it is an object of the present invention to provide an accurate and efficient process to replace the existing adhesive application process, which allows the area of adhesive to extend to the periphery of the substrate to which it is applied. This has not been possible before in the manufacture of disposable absorbent articles at conventional production rates.

The present invention relates to a process for applying a region of adhesive to a first surface of a substrate for a disposable absorbent article. The process includes the following steps:

(a) Providing a series of individual monolithic substrates, each monolith having a usable first surface.

(b) Feed a series of individual monolithic substrates (rather than continuous substrate fibers) into the machine in the machine direction.

(c) Applying an area of adhesive to the first surface of each monolithic substrate by continuous roll printing. In this process, at least a portion of the perimeter of the adhesive region is overlapped with the perimeter of the first surface of each monolithic substrate. Preferably, the printing of the roll coats the entire surface of the first substrate with the adhesive such that the area of adhesive is completely aligned with the perimeter of the first surface.

The roll printing step in the process of the present invention is preferably provided with a rotating transfer roll to transfer the adhesive. The transfer roller continuously receives adhesive at the receiving portion of its path of rotation. The transfer roller transfers the adhesive onto the first surface at the transfer portion of its path of rotation. Since the individual pieces occur intermittently, the adhesive is delivered discontinuously.

Adhesives are typically hot-melt and are typically provided in a liquid state after being melted. Thus, the receiving portion of the path of rotation of the transfer roller is typically within a container containing the adhesive in a molten state.

In one embodiment of the process of the present invention, the region of adhesive provides a means for the separate monolithic substrate to be permanently attached to the remainder of the disposable absorbent article.

In another embodiment of the process of the present invention, the disposable absorbent article for use in the user's underpants has a panty fastening adhesive that attaches the absorbent article to the user's underpants, and the connection is releasable. of. The panty fastening adhesive is provided by the process of the present invention, which typically cuts a continuous substrate into individual pieces on which areas of the panty fastening adhesive are applied to obtain a disposable absorbent supplies. Such absorbent articles are generally sanitary napkins, menstrual pads or pantiliners, which all include a topsheet, a backsheet and an absorbent core positioned between the topsheet and the backsheet. Typically the backsheet will be the first surface on which the adhesive areas will be printed according to the process of the invention.

Pants fastening adhesives are generally covered with a continuous strip as the removable covering means, which is in most cases a silicone-coated release liner. The release liner is placed in a continuous strip over the adhesive areas of the individual absorbent articles, and the continuous strip is then cut at gaps between the individual absorbent articles to obtain individual disposable articles. Alternatively, the continuous strip of removable covering means may not be cut but stored for later removal of the absorbent article from the continuous strip of removable covering means.

In a possible embodiment of the process according to the invention, the adhesive is applied from the bottom onto the first surface, which ensures that no dripping occurs during the application of the adhesive, without the need for additional protection against dripping.

The process of the present invention allows the adhesive area to have a shape that includes portions that are neither parallel nor perpendicular to the machine direction, and preferably are not linear.

At least a portion of the perimeter of the area of adhesive applied to the first surface coincides with the perimeter of the surface of the material to which the adhesive is applied. The adhesive areas preferably cover the entire surface of the first material so that their perimeters will overlap completely.

The adhesive area acts as a peel-off attachment, as does the release paper and the shorts fastening adhesive. However, the process described above is not limited to the use of this adhesive, which can also permanently join the first and second materials together.

Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. In the attached picture:

Figure 1 is a schematic diagram of one embodiment of the process of the present invention.

Fig. 2 is a schematic sectional view of a printing device used in the adhesive printing step of the present invention.

Figures 3-14 illustrate interchangeable engraved grooves and their cross-sectional configurations for use in the rotating conveyor roll of the present invention.

Absorbent articles have a body-facing side, a garment-facing side, and an absorbent structure, wherein the body-facing side is generally a liquid-permeable substrate having a fibrous or film-like structure, commonly referred to as a topsheet; The garment side is preferably liquid-impermeable but breathable, commonly referred to as the backsheet; and the absorbent structure is placed between the body-facing side and the garment-facing side, generally referred to as the absorbent core. The absorbent article has a longitudinal axis and a transverse axis and can have any base and components used in the art. In particular absorbent articles may have lateral wrapping base members, side flap members or wings and various stretchable, elastic members.

Absorbent articles for absorbing liquids will be described below using sanitary napkins or pantiliners as examples. Of course, products such as adult or baby diaper pads with adhesives can also use the process of the present invention.

Preferred sanitary napkins or pantiliners made in accordance with the present invention have a pair of side wrapping base members or "panty covering members". They overlay the wearer's shorts to reduce side soiling (ie, soiling the sides of the crotch of the shorts) and they are generally smaller than normal side flaps or flaps.

Whether integral with the absorbent article itself or separately formed and joined together, the improved performance of the lateral wrapping members is also in that they are extensible in a direction parallel to the longitudinal and/or transverse axis. This extensibility may be present in all or only a portion of the lateral wrapping member. Extensibility can be achieved by pleating or ring rolling these sections.

A typical sanitary napkin or pantiliner comprises a liquid permeable topsheet, a liquid impermeable backsheet connected to the topsheet and an absorbent core positioned between the topsheet and the backsheet. There is an adhesive area on the backsheet to form a pant fastening adhesive which is covered by a release paper or the like before the absorbent article is used.

The present invention relates to a process for making a disposable absorbent article having a first material and a second material joined together by an adhesive. The material is any material commonly used in disposable absorbent articles. Included in the process is the need to provide a permanent and releasable adhesive surface, thus including covering the area of the adhesive on the garment facing surface covered by a protective covering such as a release liner.

During the production of absorbent articles, some adhesive connections are generally formed, and the process of the present invention can be used in all or part of or at least one of the processes. Thus the application of the present invention which will be described hereinafter is generally advantageous for disposable absorbent articles.

The adhesive applied in the process of the present invention may be any adhesive. , hot melt adhesives generally comprising a thermoplastic base material, mixed with an adhesive resin or comprising a mixture of various such materials may be used in the process of the present invention. Typical hot melt adhesives have a minimum melting temperature of about 80°C and often reach about 100°C. Of course, these hot melt adhesives should be able to maintain their adhesive properties throughout the processing, storage, transportation and use of the disposable absorbent article until the disposable absorbent article is discarded. Generally, the highest temperature that the adhesive is subjected to during the entire process is the use temperature when the disposable absorbent article is used on the human body - 40°C, but higher temperatures can also occur, for example, when the absorbent article is placed on the human body. In the case of a car under the sun, the temperature here is reported to be 60°C or higher.

When applying the adhesive with a printing roller according to the present invention, the cohesive force of the adhesive should be smaller than the force with which the adhesive adheres to the printed substrate, and the cohesive force inside the substrate printed with the adhesive should be lower than that of the adhesive. The cohesion is large. If these forces do not correlate properly, a portion of the substrate will detach from the substrate and adhere to the adhesive surface of the print roll. To ensure that this does not happen, it is necessary to maintain close temperature control at all times, since the cohesion of hot melt adhesives is highly dependent on the temperature of the adhesive. A simple experiment for those skilled in the art can immediately determine whether adhesive roller printing can be performed on a substrate, as well as determine the temperature required for the adhesive.

In order to more fully evaluate the utility of the process of the present invention, a typical disposable absorbent article is described below. top sheet

The topsheet is compliant, soft to the touch and non-irritating to the wearer's skin. Suitable topsheets are well known in the art, especially those disclosed in the pending patent application "Disposable Absorbent Articles With Specific Shaped Panty Fastening Adhesives".

When referring to the topsheet, either multilayer or single layer structures are contemplated. The subject matter of the process of the present invention is the attachment of the topsheet to the rest of the absorbent article or the attachment of the interior of a multilayer topsheet. Hygroscopic structure

When referring to absorbent structures, either multilayer or single layer structures are contemplated. The subject matter of the process of the present invention is the joining of absorbent structures to other parts of absorbent articles or the joining of interiors of multilayer structures. Suitable absorbent structures are well known in the art, especially those disclosed in the co-pending patent application "Disposable Absorbent Articles With Specific Shaped Panty Fastening Adhesive".

In order to join a surface of an absorbent structure or a layer of an absorbent structure with another surface, it is important to note the above discussion regarding cohesion and adhesion forces and their interrelationships. It has often been found that the absorbent structure of certain cellulosic fluff materials does not have the desired sufficient cohesion to allow it to be printed. In this case, a possible solution is to use an adhesive roller printing process on the joining surfaces so that the cellulose fiber absorbent structure or the layers of the absorbent structure are joined together. Negative

The backsheet is primarily used to prevent leakage of absorbed exudates and to retain them within the absorbent structure so as not to wet articles that come into contact with the absorbent structure, such as drawers, panties, pajamas, underwear, and the like. Suitable backsheets are well known in the art, particularly those disclosed in the co-pending patent application "Disposable Absorbent Articles Having Specific Shaped Panty Fastening Adhesives". When referring to a backsheet, either multi-layer or single-layer structures are contemplated. The subject matter of the process of the present invention is the joining of the backsheet to the rest of the absorbent article or the joining of the interior of a multilayer backsheet. Adhesive for shorts

The backsheet generally forms the garment-facing side of the absorbent article on which the pant fastening adhesive is located. The pant fastening adhesive may comprise known adhesives or glues for this purpose. These adhesives are generally pressure sensitive and remain tacky well at their application temperature.

Suitable non-extensible adhesives are Savare LA203 and Savare LA303 produced by Savare I.C. of Milan in Italy, Coramelt 867 produced by Koemmerling in Pirmasens in Germany, Fuller D3964ZP and Fuller H2238ZP produced by H.B Fuller Co. In Lueneburg in Germany. Suitable adhesive fastening means are also described in US Patent No. 4,917,697.

It is a feature of the present invention that the shape of the pant fastening adhesive region may include non-rectilinear portions which do not coincide with the periphery of the garment facing side of the absorbent article. The panty fastening adhesive need not but can be coextensive with the garment facing side of the sanitary napkin.

Prior to use of the absorbent article, the panty fastening adhesive is generally protected by a protective covering to prevent undesired soiling or sticking to any surface. The protective covering is a silicone coated release paper, a plastic film or any easily removable covering. The protective covering means may be a single integral piece or may comprise parts of, for example, multiple pieces covering the adhesive areas respectively. The protective covering may also serve other functions, such as providing individual packaging of the absorbent article or providing a disposal function. Process step of the present invention

Preferred embodiments of the underpants fastening adhesive for sanitary napkins of the present invention will be described below with reference to the accompanying drawings.

The process of the present invention is shown in Fig. 1, wherein a series of independent monolithic substrates (by "independent" substrates is meant the entire sanitary napkin 10 without panty fastening adhesive) are pressed by machine along the substrate conveying path. Directions are fed into the system. In the second step, the continuous material 20, the release paper, is also fed into the system. FIG. 1 also shows a schematic view of the roller printing unit 30 for providing the adhesive 2 to the first surface 11 of the sanitary napkin 10 .

The continuous delivery of the adhesive 2 to the first surface 11 is shown in the detailed cross-sectional view of FIG. 2 . The adhesive 2 is delivered from the roller printing unit 30 only when the roller is actually in contact with the sanitary napkin 10, that is, in a discontinuous manner.

As can be seen in Figure 2, the sanitary napkin 10 is conveyed in the machine direction (ie generally to the right as shown) by the material guide system 12. The sanitary napkin 10 is conveyed from a material guide system 12 to another material guide system 14 which conveys it to a roll printing unit 30 .

The roll printing unit 30 includes a rotating transfer roll 31 . The circular section of the rotary transfer roller 31 shows the rotation path of the rotary transfer roller 31 . At the receiving portion 34 of the path of rotation the roller 31 is immersed in a container 36 of adhesive. This is typically the adhesive in the molten state within the roll printing unit 30, which is maintained at a constant temperature by heating elements (not shown). Also the roller 31 may preferably have internal heating means, eg the roller has passages for hot oil or water in order to keep the surface of the transfer roller 31 at a constant temperature.

The delivery roller 31 is wetted with the adhesive in a molten state at the receiving portion 34 of the rotation path. The surface of the roller is continuously rotated along the path of rotation out of the adhesive container 36 while excess adhesive is scraped off the rotating transfer roller 31 by scraper blades 35 . The scraping blades 35 are substantially suspended from the surface of the rotating conveyor roll 31 and may be held at a constant nip by spacer rings or other means for maintaining distance. It is also possible to apply a constant pressure on the cylinder by means of a spring scraper disc 35 or other means known in the printing art. In addition, the amount of adhesive sticking to the rotating transfer roller can be determined by the temperature and viscosity of the adhesive 36 in the molten state contained in the container and the length of the receiving portion of the rotating path, so that the scraping disc 35 can also be removed. needed.

The next path of the rotating transfer roller is the transfer portion 33 of the rotating path where the adhesive 2 is transferred from the transfer roller onto the first surface 11 . In order to transfer the adhesive 2, the adhesive force between the adhesive 2 and the first surface 11 should be or greater than the cohesive force inside the adhesive, or greater than the adhesive force between the adhesive 2 and the surface of the transfer roller 31, Or greater than both at the same time. Once the adhesive 2 is transferred onto the first surface 11 , it is further transferred away with the sanitary napkin 10 and attached to the release paper 20 .

The material guide system 14 acts as a support for the individual sanitary napkin 10 during the printing process. Material guide system 14 receives individual pieces, such as sanitary napkins, from material guide system 12 . As shown in FIG. 2, material guide system 14 holds individual substrate monolith 10 against gravity. It is also possible to use any known method to achieve the above object, in particular the method of upward vacuum suction relative to the direction of gravity. Figure 2 shows a vacuum chamber 15 over which the web transfer surface of the guide system 14 moves.

In particular, the material guide system 14 must hold the individual substrate sheets in tight contact with the conveying portion of the rotary path because the adhesive separates from the print roll surface at the contact portion of the two and separates from the print roll surface Where the first surfaces 11 of the substrate 14 are held together. As an example, an enhanced vacuum suction or other means known in the art may be employed at this point. The force required by the guide system 14 for holding the single sheet must obviously be greater than the force of the adhesive to hold the single sheet on the printing roller 31, otherwise the single sheet will no longer continue to advance along the conveying path as shown in Figure 2 and stick to it. A production stop is caused on the adhesive transfer roller 31 .

In the process of the present invention, the release paper 20 is also introduced by a guided conveying system 22 as shown in FIG. 2 . The interval between applying the adhesive 2 between the first surface 11 and the second surface 21 and joining the release paper to the sanitary napkin must be carefully set so that the adhesive remains in the desired state for adhesive attachment.

The pattern of adhesive is continuous in the machine direction 1, but it is also possible to set the pattern to be continuous or discontinuous in a direction parallel to the axis of rotation of the rotating transfer roller 31 as determined by the printing surface of the rotating transfer roller 31 . The pattern is preferably formed by engraved grooves or indentations 32 having rectilinear lines, most preferably the entire surface of the roll has engraved grooves or engravings 32 .

The entire surface of the transfer roller 31 including the engraved grooves will be wetted with the adhesive 2 at the receiving portion in the path of rotation of the transfer roller 31 . At the scraping disc 35, the adhesive sticking to the outside of the engraved groove 32 on the surface of the roller is scraped off and guided back to the container 36 of the adhesive in the molten state, only the remaining adhesive in the engraved groove , the adhesive is conveyed to the conveying portion of the rotating path of the rotating conveying roller.

The term "engraved groove pattern" here refers to a macroscopic area which is applied to the first surface 11 as an adhesive area. The pattern consists of a plurality of engraved grooves 32, which are generally small enough to cover the entire adhesive area with a constant amount of adhesive per surface area. As an example, the engraved groove pattern may be straight or striped. Other adhesive applications could use other novel patterns, such as a peripheral pattern to attach the backsheet to the topsheet along the periphery of the absorbent core. In addition, there are many patterns that can be used, and it is easy for those skilled in the art to determine the suitable pattern according to the needs of the application.

As can be foreseen by those skilled in the art, in addition to the overall pattern of engraved grooves, the shape of the individual engraved grooves on the surface of the rotating conveyor roller, the depth of the engraving and the distribution density of the grooves will be decisive. 11 The key parameters on the adhesive quantity and basis weight value. For example, it has been found that the typical pattern of engraved grooves shown in Figures 3 to 14 is suitable for application to disposable absorbent articles such as sanitary napkins and incontinent pads. Figures 3 to 14 show top views of engraved grooves viewed from the surface of the rotating transfer roll. For orientation, a line (indicated by numeral 3 ) is shown in the figure, which is parallel to the axis of rotation of the rotary transport roller 31 .

As can be seen from Figure 1 or 2, the above-mentioned direction is generally perpendicular to the machine direction defined by the production path of the first material.

Fig. 3 shows a square pyramid-shaped engraving groove, the concave angle of which is about 45°. FIG. 4 is a cross-sectional view of the engraved groove shown in FIG. 3 . Engraving grooves at other angles such as 30°, 15° or steep 60° or 75° are suitable for this. FIG. 5 shows a square pyramid-shaped engraving groove similar to FIG. 3, except that the central part of the pyramid is truncated, as shown in the cross-sectional view of FIG. 6.

The direction of each engraved groove can of course vary with respect to the direction of the axis of rotation 3 . Comparing FIGS. 5 and 7 , it can be seen that they show the same truncated pyramid-shaped square engraved grooves, but their position relative to direction 3 is changed. Figure 8 shows a truncated engraved groove similar to that shown in Figure 7, except that the corners of the square portion are rounded. Figure 9 shows engraved grooves similar to those shown in Figure 8, but the direction of the engraved grooves is different. FIG. 10 is a cross-sectional view of the engraved groove shown in FIG. 9 .

FIG. 11 shows another embodiment of engraved grooves, which are truncated hexagonal pyramids. A cross-sectional view of such an engraved groove is shown in FIG. 12 . Fig. 13 and Fig. 14 show yet another embodiment, that is, an engraved groove with a circular periphery.

The outer diameter and distribution density of these engraved grooves are mainly determined by the desired result of the adhesive printing step of the present invention. The preferred range of engraved grooves will be given below.

The depth of each individual engraved groove can be from 0.01 mm when only a small amount of adhesive needs to be provided to 0.8 mm when a large amount of adhesive needs to be delivered. It is known that the side of the square engraved groove or the diameter of the circular engraved groove can be 0.01 mm to 2.5 mm. Those skilled in the art can easily select the outer diameter dimensions of the engraved grooves which are neither square nor circular, which are of course also measured on the surface of the rotating transfer roller. It is known that when the distance between the engraved grooves is 0.5 times to 50 times the depth thereof, an approximately uniform adhesive distribution can be obtained on the entire engraved groove pattern.

The number of engraved grooves per unit area depends on the size of a single engraved groove. Adhesive delivery can be made more uniform across the bonded area by increasing the number of engraved grooves and reducing the size of the individual engraved grooves, resulting in a "full surface engraved recess" parallel to the entire adhesive area. Groove", but this requires a distance ring or similar device to keep the scraping blade at a certain distance from the roller.

As an example, an engraved groove that has been successfully used within the scope of the present invention is the engraved groove with a depth of 0.067 mm, a size of 0.2 mm×0.2 mm, and 567 grooves per square centimeter as shown in FIG. 6 . Following the general discussion above, these engraved grooves are used to attach the panty fastening adhesive to the polyethylene backsheet of the sanitary napkin. The panty fastening adhesive area is kept at a constant distance of approximately 4 mm from the peripheral contour of the sanitary napkin in a so-called sub-bell shape.

Four alternative shorts fastening adhesives have been successfully tested at different temperatures, Savare LA203 at 130°C, Savare LA303 at 110°C, Fuller D3964ZP at 140°C and Fuller D3964ZP at 140°C Coramelt 867 under. All of these application tests were carried out at surface speeds not greater than 100m/min. The second material providing the second surface is a commonly used silicone release paper. Savare adhesives are available from Savare I.C. in Milan, Italy, Fuller adhesives are available from H.B. Fuller of Lueneburg, Germany, and Coramelt adhesives are available from Koemmerling in Pormasens, Germany.

Claims (9)

CLAIMS 1. A process for applying a region of adhesive on a first surface of a substrate for a disposable absorbent article, said region of adhesive having a perimeter, said process comprising: a) providing a series of individual pieces of said substrate, each said piece of said substrate having said first surface, said first surface having a perimeter, b) conveying said series of individual pieces of said substrate in a machine direction, c) applying an area of adhesive on said first surface of said single piece of said substrate, The process is characterized in that, The adhesive area is provided by continuous roll printing, which produces an adhesive area with at least a portion of its perimeter coinciding with the perimeter of the first surface. 2. The process of claim 1 wherein all of said perimeter of said adhesive region coincides with said perimeter of said first surface. 3. A process as claimed in claim 1 or 2, wherein said continuous roll printing comprises a rotating transport roll for continuously transporting said adhesive, said roll being continuous at a receiving portion of its path of rotation. receiving the adhesive, the receiving portion is located in a container containing the adhesive, and the roller continuously conveys the adhesive by rotation from the receiving portion of the roller's rotational path to the roller's The roller discontinuously delivers the adhesive onto the first surface at the conveying portion of its rotational path and due to the discontinuous presence of the individual individual pieces. 4. A process according to any one of the preceding claims, wherein said adhesive region provides a permanent attachment means of said substrate to said disposable absorbent article. 5. A process as claimed in claim 1, 2 or 3, wherein said disposable absorbent article is intended for use in the underpants of a user, and said disposable absorbent article includes a user operatively attachable article to the article. The panty fastening adhesive on the underpants of the utility model, the adhesive area provides the panty fastening adhesive. 6. The process of claim 5, wherein said disposable absorbent article is prepared from a continuous substrate, said substrate is broken to form individual absorbent articles, and said individual absorbent articles are subsequently applied The shorts are secured with adhesive. 7. The process of claim 6, wherein said disposable absorbent article is a sanitary napkin, menstrual pad, or pantiliner, comprising a topsheet, a backsheet, and an interposition between said topsheet and said backsheet. The absorbent core, said backsheet providing, in use, the garment-facing side of said article, said first surface being the garment-facing side of said backsheet. 8. The process as claimed in claim 6 or 7, further comprising the steps of: d) providing a continuous strip of removable cover means; e) placing said covering means on the adhesive area of said self-contained absorbent article, and f) Disconnecting the covering means to obtain individual disposables. 9. The process as claimed in claim 6 or 7, further comprising the steps of: c) providing a continuous strip of removable cover means; d) placing said covering means on the adhesive area of said self-contained absorbent article, and e) retaining said continuous strip of said covering means to obtain a series of disposables which can be peeled off when required.

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