WO2020130959A1

WO2020130959A1 - Optimized absorbent core layer for hygiene products

Info

Publication number: WO2020130959A1
Application number: PCT/TR2018/050849
Authority: WO
Inventors: Özlem ESEN; Çağla BEKTAŞ
Original assignee: Evyap Sabun Yag Gliserin Sanayi Ve Ticaret Anonim Sirketi
Priority date: 2018-12-20
Filing date: 2018-12-20
Publication date: 2020-06-25

Abstract

The absorbent core layer (1) to absorb the body fluids or fecal matters in hygiene products, comprising; %20-70 the pulp fibers (2), %30-80 superabsorbent polymers (SAP) (3) and increased amount of SAP (3) and pulp (2) percentage in the middle part of hygiene product. SAP (3) and pulp (2) amount in front and on back parts of the hygiene products is less, compared with the amount in the middle part. This provides the quick absorption of body fluids and fecal matters, high absorption capacity, strong core integrity and easy fit to the body.

Description

OPTIMIZED ABSORBENT CORE LAYER FOR HYGIENE PRODUCTS

DESCRIPTION

Field of the invention

The present invention relates to the optimization of 3D core layers on diapers, training pants, adult incontinence undergarments, feminine hygiene products, breast pads, care mats, bibs, wound dressing products, and the like, for increasing the absorption performance and supporting easy fit to the body.

Background of the invention

In recent years, with the sustained and rapid growth of the domestic economy, people's material and living standards have been improved and their lifestyles have become more convenient. The use of diapers by infants and the elderly has been increasing year by year. At present, there is a wide variety of baby diapers on the market in order to prevent infants from wetting their beds. Existing disposable diapers for babies rely on wood pulp and super absorbent polymer (SAP) to absorb and lock the baby's urine to keep the baby's buttocks dry. Infants less than one year old cannot control spontaneous bowel movements, defecation frequency is also more, traditionally parents use cotton pads to absorb urine in the baby's buttocks, keep the baby's buttocks dry.

Traditional diapers have a mature production process in making cotton core and making the three-dimensional guard, which can well achieve the effect of liquid absorption without side leakage. However, when the wearer lies on his back, the phenomenon of back leakage occurs. Cause clothing contamination and skin discomfort.

Absorbent articles for personal hygiene, such as disposable diapers for infants, training pants for toddlers or adult incontinence undergarments, are designed to absorb and contain body exudates, in particular large quantity of urine. These absorbent articles comprise several layers providing different functions, for example a topsheet, a backsheet and in-between an absorbent core, among other layers.

The function of the absorbent core is to absorb and retain the exudates for a prolonged amount of time, for example overnight for a diaper, minimize re-wet to keep the wearer dry and avoid soiling of clothes or bed sheets. The majority of currently marketed absorbent articles comprise as absorbent material a blend of comminuted wood pulp with super absorbent polymers (SAP) in particulate form, also called absorbent gelling materials (AGM).

The United States patent document numbered US008568566 discloses an apparatus and method for producing absorbent structures with absorbent layers with channel(s) without absorbent material, using a first moving endless surface with specific raised strip(s) and a second moving endless surface with specific mating strip(s). With the channel technology, it was claimed that the body exudates are rapidly absorbed into the absorbent core and distributed to the front and back part of it, thus provide the effective use of diaper capacity.

The United States patent document numbered US20150073366 discloses an absorbent article comprising a pair of leg cuffs with a raised section and an absorbent core comprising at least one channel at least partially oriented in the longitudinal direction of the article. The article has crotch width before use as measured between the proximal edges of the leg cuffs at the level of the crotch point of from to 70 mm to 200 mm, and a Relative Crotch Width Reduction (RCWR) of at least 30 mm/kg. In the diaper with about 80% SAP, one or more channeled structures have been formed in the absorbent core layer on a vertical plane and have been claimed to have active fluid dispersion throughout the cloth. Channels consist of gaps with no SAP. The ADL layer (acquisition and distribution layer) between the absorbent core layer and the topsheet (the top layer which touches the baby's skin) and any intermediate layers are also not found in the regions with channels. It is also mentioned that shorter small channels may be present in the front and back of the diaper. The United States patent document numbered US20150038931 discloses disposable absorbent diapers which are provided with improved comfort, fit and liquid transportation. The absorbent core of the disposable absorbent diapers includes at least one absorbent structure comprising a substrate layer and an absorbent layer with channels. It was stated that the elasticity of the absorbent core layer increased with two longitudinal channels and that the anatomical structure was more compatible with the baby's body and the fastest urine absorption was achieved by two-channeled structure.

In the state of the art, the production of one or more channels on hygiene products are in common, especially for the hygiene products including high percent of SAP in the absorbent core layer. However, the amount of absorbent material is reduced due to the location of the channels in the absorbent layer, this is because no SAP is located in the channel area. Although the fast liquid absorption and effective fluid distribution is provided on the absorbent core of diaper with the effect of channels, lower capacity of the diaper due to lower amount of absorbent material in the core (channel areas don’t have SAP) leads to leakage problems. In addition, when the capacity is full with large amount of body fluid, this is accompanied by anormal amount of core swelling which causes uncomfortable structure and makes it difficult to fit the body. In order to provide comfortable body fit of the channeled product when it is wet with body exudates, the amount of absorbent material is used even lower than before, thus provide the desired elasticity to fit the body, but causes very poor absorption capacity in the final product.

Objectives of the invention

One objective of the invention is to provide heterogeneous distribution of pulp and super absorbent polymer (SAP) in core layer without any performance loss of absorbency on diapers. Thus, the hygiene product provides superior capacity.

Another objective of the invention is to transfer the urine to the core layer quickly due to the 3D structure of core layer of diaper. Another objective of the invention is that 3D helps effective fluid distribution and prevent the deformation of diapers core integrity.

Another objective of the invention is to provide easy fit to the user body when the product becomes wet with body exudates.

Detailed description of the invention

A realized to fulfil the objective of the present invention is illustrated in the accompanying figures, in which:

Figure 1. shows a perspective view of the drum to produce the core layer of diaper. Figure 2. shows a perspective view of the production of homogenous core layer of diaper.

Figure 3. shows a perspective view of the production of optimized core layer of diaper. Figure 4. shows a perspective view of the specific mold which is prepared to produce the core layer of diaper.

Figure 5. shows a schematic view of the specific mold which is prepared to produce the core layer of diaper.

The parts illustrated in the figure are individually numbered where the numbers refer to the following:

1. Absorbent core layer

2. Pulp

3. SAP

D. Drum

M. Mold

The absorbent core layer (1) to absorb the body fluids or fecal matters in hygiene products, comprising; %20-70 the pulp fibers (2),

%30-80 super absorbent polymers (SAP) (3).

The present invention relates the absorbent core layer on the hygiene products such as diapers, training pants, adult incontinence undergarments, feminine hygiene products, breast pads, care mats, bibs, wound dressing products, and the like.

The absorbent core layer is produced by mixing the pulp fibers (2) and SAP (3) to be supplied into rotatable drum device (D). There are more than one molds and each one of all, is provided to produce the absorbent core layer (1), on the rotating drum (D). SAP (3) and pulp (2) is feeding continuously to the rotating drum (D). Feeding is proceeded in vacuum media which differentiate according to the percentage of SAP (3) and pulp (2) in the hygiene products. In the middle part of the product, amount of SAP (3) and pulp (2) is increased during the production stage by using special molds (M) with different open-close areas.

On the upper part of rotating drum (D), there is SAP-Pulp feeder and special molds (M). Percentage of SAP (3) and pulp (2) can be arranged by filling the mixture by applying the vacuum into these special molds (M) which have different open-close parts. At the same time, drum (D) is rotating and filled special molds (M) are changed with the empty ones. On the lower part of rotating drum (D), filled special molds (M) are left to belt conveyor by changing/decreasing the vacuum.

In the SAP (3) and pulp (2) feeding stage, rotating drum (D), special molds (M) are inserted to the drum. This special molds (M) are produced by sintering the stainless steel metal plate with stainless steel wire sieve. Wires are generally smaller than 100 mesh, preferably smaller than 90 mesh. Metal plates or metal sheets are generally in the range of 100-400 micron, preferably smaller than 300 microns, more preferably between 150-250 micron. More preferably between 3-85 mesh wires is used. The metal sheet and wire sieve are used together to provide the desired open and closed area on the mold (spaces) for producing the three-dimensional structure of the absorbent core layer (1). Special molds (M) are produced by spot welding. There are basically 3 layers. Bottom layer is stainless steel wire sieve with 2-10 mesh, middle layer is stainless steel metal sheet with 150-250 microns and top layer is 20-80 mesh stainless steel wire sieve. Those three layers are sintered at 200□ than stainless sheet and sieve are spot welded and re-fired.

In hygiene products, especially in diapers, using those specific production molds (M) for absorbent core layer, provide the usage of diaper with maximum yield. By using SAP (3) and pulp (2) amount in front and on back parts of the hygiene products is less, compared with the amount in the middle part to provide 3D structure. This provides the quick absorption of body fluids and fecal matters. Unlike the previous channelled technique, the use of super absorbent polymer on everywhere of the core also provides superior diaper capacity performance. In addition, unlike the prior art of hygiene products exposed to large body fluids and fecal matters and provide an uncomfortable fit and feeling, the present invention provides a hygiene product having a comfortable feel and easy fit even when it absorbs high amount of body fluids and fecal matters.

Claims

1. The absorbent core layer (1) to absorb the body fluids or fecal matters in hygiene products, comprising;

%20-70 the pulp fibers (2),

%30-80 super absorbent polymers (SAP) (3) and

increased amount of SAP (3) and pulp (2) percentage in the middle part of hygiene product.

2. The absorbent core layer (1) according to claim 1, wherein SAP (3) and pulp (2) are fed in continuously to the rotating drum (D).

3. The absorbent core layer (1) according to claim 1, wherein the percentage distribution of SAP (3) and pulp fibers (2) are arranged with special molds (M).

4. The absorbent core layer (1) according to claim 1, wherein the percentage of (SAP) (3) and pulp fibers (2) are arranged with special molds (M).

5. The special molds (M) to provide the percentage distribution of SAP (3) and pulp fibers (2) comprising,

- one stainless steel wire sieve bottom layer with 2-10 mesh,

- one stainless steel metal sheet middle layer with 150-250 microns and

- one stainless steel wire sieve top layer with 20-80 mesh.

6. The special molds (M) according to claim 5, wherein the three layer is produced by spot welding.