WO2015097330A1

WO2015097330A1 - Nonwoven fabric, manufacturing method thereof and personal hygiene wipe of said nonwoven fabric

Info

Publication number: WO2015097330A1
Application number: PCT/ES2014/070951
Authority: WO
Inventors: Carlos Viñas Pich
Original assignee: Bc Nonwovens, S.L.
Priority date: 2013-12-26
Filing date: 2014-12-22
Publication date: 2015-07-02
Also published as: ES2543895B1; ES2543895A1

Abstract

The invention relates to a nonwoven fabric which comprises fibers bound among themselves, which is characterized in that said fibers have a length of 4 to 18 mm, all the fibers being of the same length or of different lengths. The method for manufacturing the nonwoven fabric is characterized in that it comprises the steps of extruding fibers having a length of 4 to 18 mm; of carding said fibers; and of mechanically binding said fibers using pressurized water. A nonwoven fabric dispersible in water can thereby be provided, which is suitable for being used in intimate hygiene moist wipes and is smooth and spongy, and at the same time meets the current standard which enables same to be classified as disposable in water.

Description

FABRIC NON-WOVEN, PROCEDURE FOR MANUFACTURING AND TOWEL OF PERSONAL HYGIENE OF SUCH FABRIC NOT WOVEN

DESCRIPTION

The present invention relates to a non-woven fabric, which is dispersible in water and which is specially designed for use in the manufacture of wet personal hygiene wipes, which once used are thrown into the toilet bowl, dispersing in the water .

In addition, the present invention also relates to the method of manufacturing said nonwoven fabric and to a personal hygiene wipe of said nonwoven fabric.

Background of the invention

Several different technologies are known for making nonwoven fabric. Basically, these techniques differ, on the one hand, in the type of raw material used and its feeding / processing in the production line and, on the other hand, in the way of linking / linking the raw material to form the final fabric.

Thus, the first material can be continuous filament, segmented fibers or pulp, and in the case of segmented fibers the feed / process mode in the production line is carded and the bonded / bonded mode can be hydroentangled (fibers are linked mechanically with pressurized water), punching with needles (fibers are mechanically bonded with needles), thermal bonding (fibers are bonded by hot air treatment or by calendering) or chemical bonding (fibers are chemically bonded by the addition of binders , polymers, etc.).

One of the main applications of nonwovens is its use for the production of hygiene products, geotextiles, industrial, etc. Within the hygiene sector, its use in the manufacture of diapers and wet wipes stands out.

It is known that, among all the technologies for the manufacture of nonwoven fabric, the preferable technique for making baby wipes is the one that It combines the process of carding and hydroentangleting of segmented fibers (mixture of fibers of natural origin and synthetic fibers), due to the following advantages that it brings, with respect to the other manufacturing methods mentioned previously:

- Softness and fluffiness: the spongy and soft touch of the original fiber is maintained through the carding and hydroentangleting process.

- Resistance to the manipulation, necessary so that the wipe does not break during its packaging and its use (the non-woven fabric from this process allows a certain elongation).

- Low cost (it is not necessary to add chemicals or apply long drying times).

Another application for non-woven fabric is its use for the preparation of water-dispersible personal hygiene wipes.

Unlike the baby wipes mentioned above, this product, when thrown into the toilet after use, goes to wastewater treatment plants, so it must be biodegradable and, in addition, should not generate any problem in the water collection system.

In this regard, the EDANA ("European Disposables And Nonwovens Association") and INDA ("International Nonwovens and Disposables Association") associations have agreed on standards that non-woven fabrics must meet in order to be certified as disposable in water.

Currently, although biodegradable non-woven fabric can be manufactured (using 100% natural fibers), there are no water disposable personal hygiene wipes on the market (that is, they comply with this new EDANA / INDA regulation ) manufactured from fiber and hydroentangleted carding technology.

As a general rule, for the carding of the fiber its length is required to be 30 to 60 mm, to avoid problems in the processing and risks of breakage of the equipment that are part of the production line. Due to this fiber length, the resulting tissue is strongly bound and does not disperse when thrown into the water. On the other hand, it is possible to manufacture non-woven fabric dispersible in water (that is, that complies with the EDANA / INDA regulations), using cellulose pulp (partially or totally) as raw material that is processed by the "wet laid" technique or "air laid", but not by carding. The pulp is a cellulose pulp that is obtained from the mechanical and / or chemical crushing of softwoods, while segmented cellulose fibers are made by dissolving plant material and subsequently extruding this solution to form filaments of Cellulose, which is finally cut to obtain segmented fibers.

This pulp has certain inconveniences for the end user, such as that it is rough, it is not very spongy, and it is brittle, since it breaks easily, because the nonwoven fabric does not allow elongation. It is clear that these aspects are critical for market acceptance, given the widespread application of intimate hygiene to which this product is intended.

Therefore, the objective of the present invention is to provide a water-dispersible non-woven fabric suitable for use in wet wipes of intimate hygiene that is soft and spongy and, at the same time, complies with current regulations that allow it to be classified as disposable in Water.

Description of the invention With the non-woven fabric of the invention, the aforementioned drawbacks are resolved, presenting other advantages that will be described below.

According to a first aspect, the present invention relates to a nonwoven fabric, comprising fibers bonded together, and characterized in that said fibers have a length between 4 and 18 mm, all fibers of the same length or of different length may be.

Advantageously, said fibers are curly fibers, including 2 to 10 curls / cm.

In addition, said fibers are preferably natural fibers, such as cellulose, viscose or rayon.

If desired, said nonwoven fabric may comprise between 55% and 45% of fibers between 1 1 and 18 mm, between 25% and 15% of fibers between 8 and 1 1 mm, and between 35% and 25% of fibers between 4 and 8 mm.

According to a second aspect, the present invention also relates to a process for the manufacture of a non-woven fabric as indicated above, comprising the steps of:

- extrusion of fibers with a length between 4 and 18 mm;

- carding said fibers; Y

- mechanical bonding of said fibers with pressurized water.

Advantageously, the process for manufacturing a nonwoven fabric according to the present invention comprises the mechanical curling stage of said fibers after said extrusion of the fibers, and in the curling stage the fibers are preferably curled with 2 to 10 curls / cm

According to a third aspect, the present refers to a personal hygiene wipe, which is formed from the non-woven fabric indicated above and which is manufactured in accordance with the above procedure.

The non-woven fabric according to the present invention has, among others, the following advantages: - Complies with current regulations to be classified as disposable in water;

- It is soft and fluffy, since the spongy and soft touch of the original fiber is maintained by the carding and hydroentangleting process;

- It is a non-brittle product, as it offers a resistance to handling, necessary so that the wipe does not break during use (the non-woven fabric from this process allows a certain elongation). - It is low cost, since it is not necessary to add chemicals or apply long drying times.

DESCRIPTION OF A PREFERRED EMBODIMENT The nonwoven fabric according to the present invention is biodegradable and water dispersible which is obtained by carding technology (by means of rotating cylinders provided with spikes and placed very close to each other) and hydroentangleted (linked from fibers mechanically with water under pressure) using extruded fibers of natural origin (for example, viscose or rayon cellulose) of a length of 4 to 18 mm and with a recommended level of curl of 2-10 curls / cm, and, preferably, curly mechanically.

The fact of limiting the length of the fiber to 4 to 18 mm is not random, but it is because when the length is greater than 18 mm, the resulting product does not meet water dispersability standards. This is due to the inverse relationship between the number of knots per fiber and their degree of dispersibility. In order to reduce the number of knots between fibers generated in the carding and hydroentangleting process, it is necessary to reduce the length of the fibers. According to the calculations made, this length should be ≤ 18mm. When the length is less than 4 mm, it is not possible to process the fiber.

It should be noted that in the same non-woven fabric according to the present invention, the length of the fibers can be different from each other, that is, it can comprise between 55% and 45% of fibers between 1 1 and 18 mm, between 25% and a 15% of fibers between 8 and 1 1 mm, and between 35% and 25% of fibers between 4 and 8 mm, as indicated in Example 2 according to the present invention.

The fact that the fiber is optionally rice is due to the further improvement of the soft and spongy touch of the nonwoven fabric obtained by carding and hydroentangling the fiber.

Therefore, with this new non-woven fabric product, the need to be able to make water-dispersible personal hygiene wipes that, in turn, have at least the same softness, fluffiness and resistance properties demanded by the market.

An example of the nonwoven fabric according to the present invention and a comparative example, indicating its properties, are included below.

The following analysis methods have been used to determine their properties:

- Fluffiness: It is provided by the thickness of the nonwoven fabric (expressed in millimeters and measured according to the EDANA ERT-30.5-99 standard).

- Softness: A blind test is performed consisting of the evaluation by 5 different people of the softness of several samples of nonwoven fabric, so that each person scores the softness on a scale of 0 to 5 (0 being a rough fabric and 5 a very soft product).

- Elongation (expressed in% and measured according to EDANA ERT. 20.2-89) in MD (machine direction) and CD (transverse direction), which is related to the deformability of the nonwoven fabric before breaking. Thus, the greater the elongation, the product obtained is less brittle.

- Dispersability in water: It is evaluated by means of the test called "Slosh Box Desintegration Test" in accordance with the EDANA / INDA regulations ("Guidelines for Assessing the Flushability of Disposable Nonwovens Products"; Third edition; June 2013).

Within the EDANA / INDA regulations (previously mentioned), the "Slosh Box Desintegration Test" is established to determine if a non-woven fabric is dispersible in water. Through this test, the disintegration capacity of a product is evaluated when it is subjected to mechanical agitation in the water.

The system used in this test basically consists of an oscillating box (26 rpm) containing 2.0 liters of water, into which an individual product (for example, a wipe) is introduced for 3 hours. Subsequently, the rest of the product dispersed in water is filtered through a 12.5 mm pore diameter mesh.

The residue retained in the mesh is dried and the percentage of product (non-woven fabric) passing through the 12.5 mm mesh (% dispersed mass) is measured gravimetrically. This test must be carried out with 6 samples of the product.

Thus, a non-woven fabric is considered dispersible in water when the percentage of mass dispersed through the 12.5 mm mesh is at least 25% in at least 80% of the analyzed samples. .

Both the example according to the present invention and the comparative example are nonwoven fabrics made of viscose cellulose fibers by carding and hydroentangling.

Curly ElongaElonga¬

Length Dispersed in Fiber Thickness Smoothness

fiber (mm) sense direction (mm) in water

(# / cm) MD CD

Example of

the invention 12 3 0.58 5 28.2% 43.0% 98.0% 1

50% 12

Example 3

mm

the invention 0.61 5 34.8% 45.9% 100.9%

20% 10

2 4

mm 30% 6

4

mm

0

Example

40 (fiber no 0.49 5 0.3% 13.1% 99.7% comparative

curly)

From the above table it can be seen that the example of nonwoven fabric according to the present invention is more spongy (due to its greater thickness), it disperses much better in water, it can be lengthened much more in the MD direction.

As indicated above, the present invention also relates to a personal hygiene wipe, formed from said nonwoven fabric and manufactured by the procedure indicated above. Although reference has been made to a specific embodiment of the invention, it is apparent to one skilled in the art that the nonwoven fabric, the procedure and the personal hygiene wipe described are susceptible of numerous variations and modifications, and that all the mentioned details can be substituted by other technically equivalent ones, without departing from the scope of protection defined by the appended claims.

Claims

1. Nonwoven fabric, comprising fibers bonded together, characterized in that said fibers have a length between 4 and 18 mm, all fibers being the same length or different length.

2. Nonwoven fabric according to claim 1, wherein said fibers are curly fibers.

3. Nonwoven fabric according to claim 1 or 2, wherein said fibers are natural fibers, such as cellulose, viscose or rayon.

4. Nonwoven fabric according to claim 2, wherein said fibers include 2 to 10 curls / cm.

5. Nonwoven fabric according to claim 1, comprising between 55% and 45% of fibers between 11 and 18 mm, between 25% and 15% of fibers between 8 and 1 1 mm, and between 35% and 25% fibers between 4 and 8 mm.

Method for manufacturing a nonwoven fabric according to any one of the preceding claims, characterized in that it comprises the steps of:

- extrusion of fibers with a length between 4 and 18 mm;

- carding of said fibers; Y

- mechanical bonding of said fibers with pressurized water.

7. Method for manufacturing a nonwoven fabric according to claim 6, comprising the mechanical curling step of said fibers after said extrusion of the fibers.

8. Procedure for the manufacture of a non-woven fabric according to the claim 7, wherein in the curling stage the fibers are curled with 2 to 10 curls / cm.

9. Personal hygiene wipe, which is formed from the nonwoven fabric according to any one of claims 1 to 5.