HK1227955A1 - Flushable hydroentangled moist wipe or hygiene tissue - Google Patents

Description

Flushable hydroentangled wet wipe or toilet paper

Technical Field

The present invention relates to a flushable hydroentangled tissue or toilet paper impregnated with a wetting composition, wherein the nonwoven material comprises cellulose pulp fibres and/or staple fibres.

Background

Pre-moistened towels or toilet tissue are often used for cleaning different parts of the human body. Examples of specific uses are baby care, hand wiping, feminine care, and replenishment of toilet or toilet paper.

Because a long period of time often passes from the time of manufacture until the time of use of the pre-moistened wipes, they must have sufficient structural integrity for their intended wiping function during this period of time. The addition of wet strength agents to paper towels provides such wet integrity. However, particularly when used as toilet paper, there is a strong desire that paper towels or toilet paper can be flushed in a sewer without causing problems with clogging pipes and filters. Paper towels or toilet tissue having a high wet strength do not break up or break down into small fiber clusters when flushed in a conventional domestic toilet system, which may lead to clogging of the drainage system.

Previously wet flushable pre-moistened wipes and toilet paper on the market were flushable due to their small volume. They can move along drainage and sewer pipes but are not easily dispersed and may therefore cause problems with clogging pipes and filters. Currently, decomposable materials are used for flushable paper towels and toilet tissue.

US 4,755,421 discloses hydroentangled decomposable nonwoven fabrics for use as flushable wet wipes. The fabric comprises a mixture of pulp fibers and short length regenerated cellulose fibers. No binder was added.

US 2004/0013859 discloses a hydroentangled nonwoven web for use as a wet wipe which disintegrates on mild agitation in water. The nonwoven web comprises natural cellulose fibers and highly crystalline cellulose fibers, preferably lyocell (lyocell) fibers. A binder is also added, for example in the form of binder fibers. Nonwoven webs are believed to have high wet tensile strength, but disintegrate or disperse when gently agitated in water, making them flushable in a sewer.

WO 2013/015735 discloses flushable hydroentangled wet wipes. The tissue material comprises pulp fibres having a length of 8-20mm and poly (lactic acid) fibres. The tissue is free of added binders and wet strength agents.

JP 2008073357 discloses hydroentangled tissue materials having water-soluble properties. The tissue material comprises hydrophilic fibers and fibers having a modified cross-section.

JP 2012057289 discloses a flat hollow rayon fiber with wrinkles formed in the outer surface. These flat rayon fibers can be used in different kinds of products, of which one example mentioned is a water-dispersible paper.

However, there remains a need for a wet wipe or toilet paper that has sufficient structural integrity for its intended wiping function, but is readily disintegrable upon flushing in a sewer.

Disclosure of Invention

It is therefore an object of the present invention to provide a wet wipe or hygiene tissue which has sufficient wet strength for its intended use but which disintegrates when the sewer is flushed. The object of the invention is solved by the following solutions: the wet tissue or the sanitary napkinThe paper comprises a hydroentangled nonwoven material impregnated with a wetting composition, said nonwoven material comprising cellulose pulp fibres and/or staple fibres, wherein said nonwoven material further comprises a nonwoven material having a thickness of 2-50mm²And an aspect ratio of 1-10.

These disintegrating elements can create points in the nonwoven material which weaken the material, resulting in a material that disintegrates or disperses in water under mild agitation, such as that present in a standard sewer.

The flushable tissue or toilet tissue may comprise 0.5-2.5 wt.% of said disintegrating elements, calculated on the dry weight of the tissue or toilet tissue.

The disintegrating elements may comprise a material having a disintegration time, measured by french standard NF Q34-020, different from that of the nonwoven material.

The disintegrating elements may comprise a material having a longer disintegration time as measured by french standard NF Q34-020 than the disintegration time of the nonwoven material.

The decomposing element may contain a material selected from the group consisting of: plant elements, paper containing wet strength agents, nonwoven materials, film materials.

The decomposition elements may have an aspect ratio of 1-7.

The thickness of the disintegrating elements may be between 50 μm and the thickness of the nonwoven material, preferably 1mm or less.

The disintegrating elements may be embedded by fibres in the nonwoven material.

The decomposing element can have a different color or shade compared to the rest of the nonwoven material.

The decomposition element may have a decorative and/or informative shape, such as symbols, words, logos, etc.

Drawings

Figure 1 is a schematic representation of a hydroentangled material comprising a disintegration element of the invention.

Fig. 2a-h are schematic diagrams of exploded elements with different shapes and illustrate how the aspect ratio is measured.

Detailed Description

The pre-moistened wipes or toilet tissue of the present invention comprise a hydroentangled nonwoven material impregnated with a wetting composition. Depending on the intended use, the wetting composition may comprise water and other ingredients in major proportions. Wetting compositions useful for wet wipes and toilet tissue are well known in the art.

Hydroentanglement or hydroentanglement is a technique introduced during the seventies of the twentieth century to form nonwoven webs, see, for example, CA patent No. 841938. The process involves forming a dry-laid (drylaid) or wet-laid (wetlaid) fibrous web, after which the fibers are entangled by very fine water jets under high pressure. Several drainage jets are directed at the web supported by a movable porous support or perforated cylinder. During this process, the fibers entangle with each other, providing sufficient bond strength to the web without the use of chemical adhesives. The entangled fiber web is then dried. The fibres used in the material may be natural fibres, in particular cellulose pulp fibres, manmade staple fibres and mixtures of pulp fibres and staple fibres. Hydroentangled materials can be produced in high quality at reasonable cost and have a high absorption capacity.

The tissue or hygiene tissue of the invention may comprise a mixture of cellulose pulp fibres and manmade fibres, preferably biodegradable manmade fibres such as regenerated cellulose fibres, e.g. viscose, rayon and lyocell, and/or poly (lactic acid) fibres. The length of these staple fibres may be 4-20 mm. Other natural fibers besides pulp fibers may also be included in the fiber web, such as cotton, sisal, hemp, ramie, flax, and the like. These natural fibers typically have a length of more than 4 mm.

The cellulose pulp fibers may be selected from any type of pulp and mixtures thereof. Preferably, the pulp is characterized by being entirely natural cellulosic fibers, and may contain wood fibers as well as cotton. The preferred pulp fibers are softwood papermaking pulps, but hardwood pulps and non-wood pulps, such as hemp and sisal, may be used. The length of the pulp fibers can vary from under 1mm for hardwood pulp and recycled pulp to as long as 6mm for some types of softwood pulp. Pulp fibers are advantageously used because they are inexpensive, readily available and absorbent.

A suitable amount of cellulose pulp fibers in the nonwoven material forming the wet tissue or toilet paper may be 0 to 95% by weight of cellulose pulp fibers, preferably 50 to 95% by weight of cellulose pulp fibers, and more preferably 70 to 95% by weight of cellulose pulp fibers. A suitable amount of the rayon in the nonwoven fabric material forming the wet tissue or the toilet paper may be 5 to 100% by weight of the rayon, preferably 5 to 50% by weight of the rayon, and more preferably 5 to 30% by weight of the rayon. The tissue or toilet tissue may have a basis weight of 30-100gsm, preferably 40-80gsm, based on the dry weight of the material.

The fibers forming the nonwoven material of the present invention may be wet laid, wherein a slurry containing the fibers is wet laid on a moving forming fabric by a headbox in a conventional papermaking apparatus. A particular variant of wet-laying or wet-forming is foam-forming, in which the fibres are dispersed in a foam liquid comprising water and surfactant. Alternatively, the fibers may be dry-laid on a moving forming fabric to form a dry-laid fibrous web, which is then hydroentangled.

In addition to the fibres, the nonwoven material 1 comprises disintegration elements 2 in the form of sheets having a diameter of 2mm²-50mm²And an aspect ratio L/D of 1-10, preferably 1-7. The projected surface area can be measured by image analysis.

The aspect ratio is defined as the ratio of the length L of the splitting element 2 to the width D. The length L is defined as the longest straight line that can be drawn/found in the element. The width D is defined as the longest straight line perpendicular to the line L that can be found/drawn in the element. Portions of lines L and D should not pass through the edges of the element, i.e., the entire length of lines L and D must be within the element. In case two or more lines are found to be of the same length (L1-L2- … Lx), the length L yielding the longest line D should be used, i.e. the length L resulting in the lowest L/D ratio.

Fig. 2a-h show how the aspect ratio L/D is measured for decomposition elements 2 having different shapes.

The disintegrating elements 2 are mixed with fibres, for example in a pulp for wet laying.

The disintegrating elements 2 in the form of sheets having the above-described ratio are different from the fibers and are not easily entangled with the fibers during the hydroentanglement. They form points in the nonwoven material which weaken the material, preferably in the Cross Direction (CD), thus making it easier to break down when flushed in a sewer.

The disintegrating elements 2 may be included in the nonwoven material 1 in an amount of 0.5 wt.% to 2.5 wt.%, calculated on the dry weight of the nonwoven material 1 (i.e. excluding the wetting composition). The disintegration elements 2 are preferably distributed over the entire area of the nonwoven material 1.

The decomposition element 2 may contain a material selected from the group consisting of: a plant element; wet strength paper, i.e. paper comprising a wet strength agent; a non-woven material; a membrane material. Preferably, the decomposition element 2 may contain a biodegradable material. They should also contain materials whose decomposition time (measured by French Standard NF Q34-020) differs from that of the nonwoven material, for example longer decomposition times, for example at least 10% longer decomposition times than the nonwoven material. This ensures that they remain weakening the effect of the nonwoven material until it has broken down. The thickness of the disintegrating elements should be at least 50 μm and not exceed the thickness of the nonwoven material, preferably less than 1 mm.

Examples of plant elements suitable for use as decomposition elements are petals, for example from marigold, lavender or similar flowers. Such plant elements may have a color or shade different from the nonwoven material. They may also have a fragrance and/or skin care effect.

The disintegrating element 2 may be formed from a cut sheet of sheet material, such as wet-strength paper, nonwoven or film material. The sheets may have a different colour or shade to the rest of the nonwoven material. They may also have decorative and/or informative shapes such as symbols, words, logos, etc.

Description of the test methods

The test method used to measure the disintegration time was French Standard NF Q34-020, month 8 of 1998. In addition to measuring the disintegration time, we also measured the weight of the remaining fibre mass (if any) in the test vessel. The test was performed in the following manner:

-placing the dried sample in a climate chamber at 23 ℃ and 50% humidity for a minimum of 4 hours;

-weighing the sample before starting;

decomposition to less than 1cm in the sample²Stopping the timer and recording the decomposition time when the fragments are broken;

-selecting 1: stirring was started again and continued for 10 minutes (including the initial decomposition time);

-selecting 2: the additional step of stirring for 10 minutes was omitted;

-picking up the remaining pieces with tweezers;

-placing the block in a 900ml beaker containing up to 300ml of water, waiting 5 seconds;

-pick up the block with tweezers and let the excess drip off, waiting 5 seconds;

-placing the block in a second 900ml beaker containing up to 300ml of water and waiting for 5 seconds;

-pick up the block with tweezers and let the excess drip off, waiting 5 seconds;

-placing the block on toilet paper to drain excess water;

-the block is placed in a climate chamber at 80 ℃ for 2h to dry;

-placing the dried pieces in a climate chamber at 23 ℃ and 50% humidity for a minimum of 4 h;

-weighing the mass;

the remaining weight of the dried piece was calculated as the percentage of the initial dry sample weight (dry weight of remaining piece/dry weight of sample) x 100 (%).

Examples

Hydroentangled nonwoven materials of the invention containing disintegration elements in the form of marigold petals and comparative samples without disintegration elements were tested. The samples had the following composition.

And (3) comparison:80 wt% cellulose pulp +10 wt% lyocell fibre 12mm +10 wt% PLA: poly (lactic acid) fiber 12 mm. The basis weight was 60gsm and the material was hydroentangled at 60 bar with entangling nozzles of 3 tubes/jet belts on each side of the web, the aperture of the entangling nozzles being 115 μm and the spacing between the apertures being 0.8 mm. The sample size and number of folds are suitable for samples 1-4 mentioned below.

Sample 1: 79 wt% cellulose pulp +10 wt% lyocell fibre 12mm +10 wt% PLA: 12mm of poly (lactic acid) fiber and 1 wt% of marigold petals. The basis weight was 60gsm and the material was hydroentangled with entangling nozzles of 3 tubes/jet belts on each side of the web at 60 bar. Sample size 10x25cm, folded longitudinally twice.

Sample 2: 79 wt% cellulose pulp +10 wt% lyocell fibre 12mm +10 wt% PLA: 12mm of poly (lactic acid) fiber and 1 wt% of marigold petals. The basis weight was 60gsm and the material was hydroentangled with entangling nozzles of 3 tubes/jet belts on each side of the web at 60 bar. Sample size 10x25cm, folded longitudinally once.

Sample 3：a)79wt％Cellulose pulp +10 wt% lyocell fibre 12mm +10 wt% PLA: 12mm +1 wt% marigold petals of poly (lactic acid) fibers; b)77 wt% cellulose pulp +10 wt% lyocell fibre 12mm +10 wt% PLA: 12mm of poly (lactic acid) fiber and 3 wt% of marigold petals. The basis weight was 60gsm and the material was hydroentangled with entangling nozzles of 3 tubes/jet belts on each side of the web at 60 bar. Sample size was 10x10cm with no folds.

Sample No. 4: 77 wt% cellulose pulp +10 wt% lyocell fibre 12mm +10 wt% PLA: 12mm of poly (lactic acid) fiber and 3 wt% of marigold petals. The basis weight was 60gsm and the material was hydroentangled with entangling nozzles of 3 tubes/jet belts on each side of the web at 60 bar. Sample size 10x25cm, folded longitudinally once.

Wet strength on CD was measured in water according to SS-EN ISO 12625-5:2005 for different samples, and the time to break down and the weight of the remaining cake were measured. The following results were obtained.

Sample 1

	CD wet tensile Strength1(N/m)	Basis weight2(g/m2)	Time of decomposition3(sec)	Block (wt%)
					Comparison of	24.5	62.0	163	Small, not measured
1% of calendula officinalis	24.4	63.4	139	Small, not measured
					Difference (comparative-1%):	-0.2％		-14.7％

¹average of 10 samples²Average of 15 samples³Average of 8 samples

Sample 2

¹Average of 10 samples²Average of 9 samples

Sample 3

¹Average of 5 samples

Sample No. 4

¹Average of 5 samples²Average of 4 samples³Average of 9 samples

It is interesting to note that the mixing of 1% marigold petals resulted in a significantly lower disintegration time and clumping than the control, while the CD wet strength was maintained. However, the mixing of 3% marigold petals resulted in increased disintegration time and clumping and a reduction in CD wet strength.

Claims (10)

1. A flushable wipe or hygiene tissue comprising a hydroentangled nonwoven material impregnated with a wetting composition, wherein the nonwoven material (1) comprises cellulose pulp fibres and/or staple fibres, characterized in that the nonwoven material comprises a nonwoven material having a thickness of 2-50mm²And an aspect ratio (L/D) of 1-10.

2. A flushable wipe or hygiene tissue as claimed in claim 1, characterized in that the wipe or hygiene tissue comprises 0.5-2.5 wt.% of the disintegrating elements (2), calculated on the dry weight of the wipe or hygiene tissue.

3. A flushable wipe or hygiene tissue as claimed in claim 1 or 2, characterized in that the disintegrating elements (2) comprise a material having a disintegration time, measured by french standard NF Q34-020, which is different from the disintegration time of the nonwoven material.

4. A flushable wipe or hygiene tissue as claimed in claim 3, characterized in that the disintegrating elements (2) comprise a material having a longer disintegration time as measured by french standard NF Q34-020 than that of the nonwoven material.

5. A flushable wipe or hygiene tissue as claimed in any of the preceding claims, characterized in that the disintegrating elements (2) comprise a material selected from the group consisting of: plant elements, paper containing wet strength agents, nonwoven materials, film materials.

6. A flushable wipe or hygiene tissue as claimed in any of the preceding claims, characterized in that the disintegrating elements (2) have an aspect ratio of 1 to 7.

7. A flushable wipe or hygiene tissue as claimed in any of the preceding claims, characterized in that the thickness of the disintegrating elements (2) is between 50 μm and the thickness of the nonwoven material, preferably 1mm or less.

8. A flushable wipe or hygiene tissue as claimed in any of the preceding claims, characterized in that the disintegrating elements (2) are embedded by fibres in the nonwoven material.

9. A flushable wipe or hygiene tissue as claimed in any of the preceding claims, characterized in that the disintegrating elements (2) have a different colour or shade from the rest of the nonwoven material.

10. A flushable wipe or hygiene tissue as claimed in any of the preceding claims, characterized in that the disintegration elements have a decorative and/or informative shape, such as symbols, letters, logos or the like.