EP2547819A1

EP2547819A1 - Cleaning cloth made from nonwoven fabric and method for producing it

Info

Publication number: EP2547819A1
Application number: EP10808903A
Authority: EP
Inventors: Oliver Staudenmayer; Peter Grynaeus; Hans Rettig; Holger KÖHNLEIN; Joachim Hendler
Original assignee: Carl Freudenberg KG
Current assignee: Carl Freudenberg KG
Priority date: 2010-03-19
Filing date: 2010-12-09
Publication date: 2013-01-23
Also published as: CN102741466A; AR080769A1; WO2011113462A1; DE102010012193A1; TW201138702A

Abstract

In a cleaning cloth made from nonwoven fabric, which cleaning cloth can be used, in particular, in industrial and household cleaning and in the medical, cosmetic or personal hygiene sectors, and has a carrier layer made from a fibrous web which is bound by means of a binding agent in selected surface regions and is not bound in the remaining surface regions, and at least one active ingredient with a predefined functionality in and/or on the carrier layer, it is provided according to the invention that the at least one active ingredient is bound by means of the binding agent on the carrier-layer surface and/or in the carrier layer. A cleaning cloth according to the invention is distinguished by excellent haptic and use properties and can be produced simply and inexpensively.

Description

Cleaning cloth made of nonwoven fabric and process for its preparation

description

The invention relates to a cleaning cloth made of nonwoven fabric, particularly useful in industrial and household cleaning and in the medical, cosmetic or personal care sector, with a carrier layer of a batt, which is bound in selected surface areas by means of a binder and unbound in the other surface areas, and at least an active substance with a predetermined functionality in and / or on the carrier layer. The invention further relates to a method for producing such a cleaning cloth.

Cleaning cloths based on nonwovens are widely used and usually consist of water-jet-bonded nonwoven materials. All wipes have a very soft and comfortable feel. For subjective perception and handling, materials are preferred which give the user a certain volume or feel voluminous in the application. One differentiates between dry cleaning and damp cleaning. In the wet wipes, including commonly used in the personal care sector, in the Haulshaltsreinigung or in car care, a carrier material made of nonwoven fabric, with an active substance, for example, a care product, water or alcohol or mixtures thereof, soaked, in addition to the cleaning effect of Carrier material even for the user to provide a further functionality. This additional functionality can be used for An example of this is an intensification of the cleaning effect, a skin-care effect, such as a moisturizing of the skin, or even a paint or wood care effect, to name only a few examples. Dry cleaning is, for example, cleaning with a dust wipe. In order to store the dust in the fibrous sheet, it is preferable that the cleaning side of the fibrous sheet is made relatively open.

It is usually desired that cleaning wipes not only fulfill one but several functionalities. For example, US 2005/0136099 A1 discloses a nonwoven-based cosmetic article impregnated with a skin-care lotion, which has a further functionality in addition to the cleaning action. Thus, according to US 2005/0136099 A1 punctiform elevations of microbeads (peeling grains) are provided on the surface of a nonwoven carrier, which in addition to the cleaning and care by the lotion should additionally exert an exfoliating effect on the skin. These punctiform elevations, which are applied according to the document in a separate step on a finished nonwoven carrier, consist of an elastomeric material. However, peeling granules are also known from vegetable materials, such as bamboo or ground olive kernels or from salt or sugar granules or other mineral substances.

The object of the present invention is to provide a nonwoven fabric cleaning cloth which is characterized by very good tactile properties, such as a soft feel and a large volume, and has a multifunctional cleaning effect. The cleaning cloth should also be easy and inexpensive to produce. This object is achieved with a cleaning cloth having all the features of claim 1. Claim 6 relates to a preferred Process for producing a cleaning cloth according to the invention. Preferred embodiments of the invention are described in the subclaims. According to the invention, in the case of a cleaning cloth made of nonwoven fabric which can be used in particular in industrial and household cleaning and in the medical, cosmetic or personal care sector and which is a carrier layer of a batt that is bound in selected surface areas by means of a binder and unbound in the other surface areas is, as well as at least one active substance having a predetermined functionality in and / or on the carrier layer, which binds at least one active substance by means of the binder to the carrier layer surface and / or in the carrier layer. The fact that the batt is bound only in selected areas and also provided with an active substance only in these areas, results in a maximum possible mobility of the fibers between the solidified and provided with the active substance areas. In contrast to the conventionally hydroentangled flat and less bulky nonwovens traditionally used for cleaning wipes, a cleaning wipe according to the invention is characterized by a large volume, high resilience to elasticity, high softness and a pleasant feel.

The binder used binds the batt to a nonwoven fabric. By simultaneously added active substances can be additionally achieved other functionalities and thus achieve a multifunctional cleaning effect.

By the ratio of the amount of binder used to the amount of active substance (s) and by the variation of the wettability of the batt can be very strong set, abrasion resistant products or very soft Products with surfaces that may correspond to roughened fabrics obtained. The proportions of active substance (s) can be varied over large parts. By modifying the surface of the active substances, which are usually present in particulate form, directly or indirectly from the liquor, their incorporation into the binder matrix can be varied.

The selection of the fibers to be used for the carrier layer, of the binder and of the active substance (s) takes place with regard to the respective intended use. The invention has no limits in principle here. The person skilled in the art can easily find the material combination suitable for his application here.

Thus, the fibers of the batt can consist of chemical fibers or else of natural fibers or of freely varied mixtures. As chemical fibers are preferably polyolefin, e.g. (PP, PE, CoPO), polyester (eg from PET, PBT, PTT, CoPES), polyamide (eg PA6, PA66, CoPA), polylactide, polyvinyl alcohol, polyvinyl acetate or cellulose regenerated fibers, such as viscose or lyocell, and / or corresponding binding fibers used as natural fibers, for example typically wool or cotton fibers. But other types, such as flax, hemp, sisal and the like are conceivable. Depending on the desired property profile, mixtures of corresponding hydrophilic and hydrophobic fibers may prove suitable.

The man-made fibers may in this case comprise crimpable, crimped and / or uncracked staple fibers, crimpable, crimped and / or uncurled, directly spun continuous fibers and / or finite fibers, such as meltblown fibers. With the help of an Airlaid fleece laying and the appropriate equipment also pulp can be used. Strongly crimped fibers or fibers that curl stronger in the process lead to more elastic products. The carrier layer can be constructed on one or the same or different fiber layers in multiple layers. Particularly suitable for cleaning wipes are fibers with a fiber titer up to a maximum of 10 dtex. Coarser titers are usually not used because of their high fiber stiffness. Fiber titer is preferably in the range from 0.9 dtex to 3.3 dtex, but microfibers with a titre well below 1 dtex are also conceivable. The basis weights of the fibrous webs used vary between 12 g / m ² and 100 g / m ² , preferably between 25 g / m ² and 60 g / m ² .

The binder may be a binder of the acrylate, styrene acrylate, ethylene vinyl acetate, butadiene acrylate, SBR, NBR and / or polyurethane type.

The weight ratio of fiber to solid binder content can vary between 1: 9 and 9: 1, preferably between 1: 2 and 5: 1. Added soft, sticky binder dispersions or appropriately selected binder mixtures lead to an improved dust adhesion in addition to the fiber-pile consolidation. The addition of solid substances can also achieve different effects. Added powders or microgranules from LD-PE or other polymer classes, glass particles, glitter platelets, ground vegetable raw materials (bamboo, olive pits, etc.) or mineral substances serve as exfoliating agent. Microencapsulated, particulate additives that break up during use can supplement the exfoliation effect with exiting active ingredients. Similar functions, also as an agent depot or donor possess zeolites, cyclodextrins or similar substances. Expanding microcapsules enhance the peeling effect by breaking the capsule and increasing the volume of the abrasive point. Moisture-absorbing particles are conceivable for absorbing moisture, as well as a freely selectable combination of the added solid, active substances. Active ingredients that are released from the active substances mentioned are listed below as examples, such as herbal extracts (eg Aloe Vera), oils, vitamins various types, fragrances, antimicrobial Sustanzen, anti-inflammatory substances, alcohols of all kinds (eg polyols), body lotions, detergent ingredients (soaps) or the like. This list is exemplary and not restrictive. The proportions per unit weight between binder and active substance preferably vary between 1: 0 and 1: 4.

The mixture of binder and optionally active substance, which may be based on a liquid, such as an aqueous dispersion or in the form of a paste, is preferably applied to the carrier layer in a dot pattern. This ensures a special softness and resilience of the material. The dot pattern may be regular or irregular. The present invention is by no means limited to dot patterns. The mixture of binder and active substance (s) can be applied in any desired geometries, e.g. also in the form of lines, stripes, mesh or grid-like structures, points with rectangular, diamond-shaped or oval geometry or the like.

A preferred method for producing a cleaning cloth according to the invention comprises the following measures: a) producing a carrier layer from a fiber web of fibers on a depositing device in a manner known per se,

b) optionally preconsolidating the carrier layer to produce a weak pre-binding in the batt,

c) setting a process-specific residual moisture in the batt d) producing a mixture of binder and the at least one active substance and applying the mixture to selected ones

Surface areas of the carrier layer

e) temperature treatment of the carrier layer obtained from step d) with the mixture for drying and for joining fibers of the batt through the binder to a nonwoven fabric and optionally

Crosslinking of the binder and for fixing the at least one active substance to the carrier layer surface or in the carrier layer by means of the binder and optionally together sintering of

Active substance particles.

The method described above has the advantage that it is simple and inexpensive to carry out. The bonding of the batt into a nonwoven fabric and the provision of the active substance (s), in contrast to the prior art mentioned above, in a single step. Here, the active substance or the active substances, as will be described below, depending on the desired application in a simple manner both introduced into the carrier layer and enriched on the support surface layer.

For the production of the batt, the known per se technologies can be used. For the weakly pre-bonded batt with moderate nonwoven strength, low cost fiber stocks can be used, provided they meet the handle requirements.

In the case of the use of staple fibers, it is advantageous to card these with at least one card to a batt. Preference is here given to a Wirrlegung (random-technology), but also combinations of longitudinal and / or transverse laying or even more complicated carding arrangements are possible if special nonwoven properties are to be allowed or if multi-layer fiber structures are desired. Combinations with airlaid nonwoven are also possible. The carrier layer of a batt is preferably added after the deposition of the fibers on the storage device to improve the handling the further processing steps, according to a preferred embodiment of the invention by means of a low pressure water jet method. This is preferably carried out at pressures of up to 50 bar, more preferably at hole diameters of the single or multi-row arranged water jet nozzles of 70 to 120 pm and a distance of the nozzle to the support layer of 0.2 to 0.8 mm.

It has been found that it is precisely the application of a low-pressure water jet method, the properties of a batt influenced for later use as a cleaning cloth in a particularly advantageous manner. Thus, the mechanical strength of the batt is just increased so much that further handling in the production process significantly improved. On the other hand, the weakly bonded fibrous webs are still characterized by an extremely soft touch and a large volume, making them particularly suitable for use as a cleaning cloth. Another advantage is that the batt is automatically moistened by the solidification process, so that the usual pre-wetting with water to increase the production reliability of the printing process, for example by means of padding / scooping rolls eliminated. By selecting suitable stencils on the opposite side of the low-pressure water starling method, which is facing away from the nozzle, it is possible, for example, to produce perforated, slotted fibrous batt structures, which then serve as the corresponding carrier layer. Subsequent to the preconsolidation, the fibrous web support layer is provided with a mixture of the binder and the at least one active substance. The mixture is preferably in the form of a dispersion for printing. The carrier layer can then be printed directly in a printing machine with the dispersion containing the binder and the added (s) active substances. The dispersion used preferably comprises - crosslinking or crosslinkable binders of the acrylate, styrene-acrylate, ethylene-vinyl acetate, butadiene-acrylate, SBR, NBR and / or polyurethane type, as well as

- aids,

o such as thickeners (for example partially crosslinked polyacrylates and their salts),

o dispersants,

o wetting agent,

o running aids,

Handle modifiers (for example silicone compounds or fatty acid ester derivatives) and / or

o fillers

- and if necessary of active substance (s).

The active substance or the active substances can be introduced into the carrier layer via the binder as well as enriched on its surface. Which variant is preferred depends on the desired application.

For the enrichment on the surface, the added substances or active substances are preferably in particle form, ie a dispersion of binder and particles is used. From the dispersion almost any combination of binder and particles of various kinds can be printed. It has surprisingly been found that when printing the carrier layer with a dispersion of the particles and the binder and possibly other components, the coarser particles are filtered off to a large extent on the surface of the porous support material become. The result is the formation of a colon-like structure: the coarser particles from or with the active substance (s) accumulate on the carrier surface and are bound by a part of the binder to the carrier layer surface, so that at the carrier layer surface with their ( free surface), while another part of the binder penetrates deeper into the porous support material, anchors there and leads to binding in the support material.

The size of the particles is expediently oriented on the surface to be printed, for example the desired size of a binding point in the carrier layer. In the case of a dot pattern, the particle diameter may vary between> 0 pm and 500 pm. Basically, the particle sizes of an active substance are not uniform, but follow a distribution, i. one always has a particle size spectrum. The limits given above are the respective main fractions. The particle size must be matched to the desired application quantity, point size and point distribution.

Furthermore, the size of the particles is based on the porosity of the substrate to be printed in order to ensure that the particles remain on the substrate surface. Experience from the liquid filtration show that at a particle diameter, which is about 1/3 of the average pore diameter of the support material, after all, still 90% of the particles are filtered off at the surface of the support material. With a particle diameter of the order of half the mean pore diameter, even 99% of the particles are filtered off at the carrier surface. In practice, particles with particle diameters <500 μm, preferably between 100 μm and 300 μm, have proven successful in the case of the usually used fibrous webs. The skilled person, however, it is easily possible, without inventive step with the aid of the above rule of thumb for a Carrier material with a predetermined porosity to find a suitable particle size.

The binders used are preferably (mixed) polymer dispersions with particle size δθμιτι. The binders used are commercially available products for nonwoven binding and consist of preferably aqueous polymer dispersions.

The binders used may vary in their glass transition point, but soft products tend to use "soft" binders with a Tg <10 ° C. Soft binders tend to be rather sticky, so for some applications, for example, the dust receptacle is increased Adjuvants are used to adjust the viscosity of the paste, with suitable binders the haptics of the cleaning cloth can be varied within a wide range.

Subsequent to the printing process, the material is subjected to a temperature treatment for drying and, if appropriate, crosslinking of the binder and for sintering and / or co-sintering of the added active substance (s) substances onto / with the carrier layer surface with the binder.

Then the material can be wound up. Preferred applications of the cleaning cloth according to the invention are the applications in the household, hygiene, cosmetic and / or medical field.

The invention is described below without limiting the generality with reference to two embodiments. Embodiment # 1: A 35g / m ² carded fibrous web consisting of 100% (polyester) 1 7dtex / 34mm recycled polyester fibers is pre-wetted / compacted through a 15 bar water jet die strip and attached to a second nozzle strip from the other side subjected to 35 bar water pressure. The excess water is drawn off to a residual moisture content of 160%. The solidification is very weak due to the low pressure compared to a hydroentanglement solidification. The bonded to a very soft, voluminous nonwoven fibrous web then goes into a rotary screen printing machine with 20 points / cm ² and is punctiform printed with a binder-polymer dispersion with 20 g / m ^{2 support} . The printed nonwoven fabric is dried in a belt dryer at 180 ° C., the binder is crosslinked and the polymer particles are sintered up and sintered together.

The binder-polymer dispersion is composed as follows:

Self-crosslinking butyl / acrylate polymer binder dib .; tg = -28 ° C: 15 parts of CoPolyamide powder, 80-170μ; with melting range around 109 °: 21 parts

Wetting agent a / n / i 2 part

Thickener 3 parts

Water 59 parts A nonwoven fabric is obtained with a maximum tensile force of 100 N / 5 cm, transverse 13.5 N / 5 cm and a maximum elongation at break of 61% longitudinal, transverse 190%. The added copolyamide powder has a abrasive effect and causes exfoliation. The cleaning cloth has a soft handle. It has a thickness of 2.656 mm (four-day, measured at a load of 0.5 kPa on a surface of 25 cm ² over 10 sec), resulting in a specific gravity of 0.051 mg / cm ³ . Commercially available nonwoven wipes based on 100% On the other hand, polyester fibers and a dot-shaped imprint of the prior art produced in a two-stage process have a specific gravity of 0.075 mg / cm ² and are thus firmer, that is, less soft and compact, have less volume, and can be less dense due to the higher density Save dirt. As a result, they are disadvantaged compared to the cleaning cloths according to the invention.

Embodiment # 2:

A carded fibrous web having a basis weight of 50 g / m ² , consisting of 100% (polyester) recycled fibers of 1, 7dtex / 34mm is pre-wetted / compacted through a jet strip with 15 bar water pressure and on a second jet strip from the other side subjected to 35 bar water pressure. The excess water is removed to a residual moisture content of 140%. The solidification is very weak due to the low pressure compared to a hydroentanglement solidification. The bonded to a very soft, voluminous nonwoven fibrous web then goes into a rotary screen printing machine with 10 points / cm ² and is punctiform printed with a binder polymer-expansive microsphere capsule dispersion with 30 g / m ^{2 support} . The printed nonwoven fabric is dried in a belt dryer at 180 ° C, the binder cross-linked, burst the expansive microspheres capsules and the polymer particles are sintered and sintered together and.

The binder-polymer dispersion is composed as follows:

Self-crosslinking butyl / acrylate polymer binder dib .; tg = -28 ° C: 15 parts

HDPE powder for cosmetic purposes, 100-300μ 14 parts Expanding microcapsules, 10-20μ (untreated) 7 parts wetting agent a / n / i 2 part

Thickener 3 parts Water 59 parts

A nonwoven fabric having a maximum tensile force of 130 N / 5 cm, transverse 21 N / 5 cm and a maximum tensile elongation of longitudinally 65%, transverse 204%. The added HD-PE powder has an abrasive effect and causes exfoliation, which is reinforced by the very raised points caused by the expansive microcapsules even stronger. The cleaning cloth has a soft feel, visible even in high elasticity. It has a voluminous thickness of 6.9 mm (four-ply, measured at a load of 0.5 kPa on a surface of 25 cm ² over 10 sec), resulting in a specific gravity of 0.031 mg / cm ³ .

Claims

claims

1. Cleaning cloth made of nonwoven fabric, particularly useful in industrial and household cleaning and in the medical, cosmetic or personal care sector, with a carrier layer of a batt that is bound in selected surface areas by means of a binder and unbound in the remaining surface areas, and at least one active substance with a predetermined functionality in and / or on the carrier layer, characterized in that the at least one active substance is bound by means of the binder to the carrier layer surface and / or in the carrier layer.

2. Cleaning cloth according to claim 1, characterized in that the batt crimpable, crimped and / or uncracked staple fibers, crimpable, crimped and / or uncrimped direct spun continuous fibers or finite fibers, such as meltblown fibers of polyester, polyamide, and Celluloseregenerat- / or binding fibers and / or natural fibers, such as wool or cotton fibers, as well as short-cut fiber for airlaid processes.

3. Cleaning cloth according to claim 1 or 2, characterized in that the fiber denier of the fibers is <6.7 dtex.

4. Cleaning cloth according to one of claims 1 to 3, characterized in that the at least one active substance polymer granules, microencapsulated agents, expansive microcapsules, zeolites, cyclodextrins, glass particles, (glitter platelets), mineral or vegetable powders, which may be additionally acted upon by active ingredients can, includes.

5. Cleaning cloth according to one of claims 1 to 4, characterized in that the binder and the at least one active substance are applied in a regular or irregularly distributed dot pattern on the carrier layer.

6. A process for producing a cleaning cloth according to any one of claims 1 to 5, characterized by the following process steps:

a) producing a carrier layer by depositing a batt

Fibers on a depositing device in a manner known per se, b) optionally preconsolidating the carrier layer to produce a weak pre-binding in the fiber web,

c) Setting a process-specific residual moisture

d) preparing a mixture of the binder and the

at least one active substance and applying the mixture to selected surface areas of the carrier layer and

e) temperature treatment of the carrier layer obtained from step d) with the mixture for drying and bonding fibers of the batt through the binder to a nonwoven fabric and optionally crosslinking the binder and for fixing the at least one active substance to the carrier layer surface or in the carrier layer by means of Binder and optionally together sintering of active substance particles.

7. The method according to claim 6, characterized in that the pre-consolidation takes place by means of a low-pressure water jet method.

8. The method according to claim 7, characterized in that the preconsolidation of the batt is carried out by means of low-pressure water jet method at pressures of 15 to 50 bar.

9. The method according to any one of claims 6 to 8, characterized in that the pre-consolidated batt before the application of the mixture of binder and at least one active substance is adjusted to a residual moisture content of 30 - 500%.

10. The method according to any one of claims 6 to 9, characterized in that polymers and / or mixed polymerized binders of the acrylate, styrene acrylate, ethylene-vinyl acetate, butadiene-acrylate, SBR, NBR and / or polyurethane type be used.

1 1. A method according to any one of claims 6 to 10, characterized in that the mixture of the at least one active substance and the binder is applied in the form of a dispersion.

12. The method according to claim 11, characterized in that the dispersion additionally aids such as thickeners, dispersants, wetting agents, flow aids, handle modifiers and / or fillers are added.

13. The method of claim 1 1 or 12, characterized in that the dispersion is applied by means of a screen printing process.

14. Nonwoven fabric according to one of claims 6 to 13, characterized in that the mixture or the dispersion of binder and active substance is applied in a regular or irregularly distributed dot pattern on the surface of the carrier layer.

15. The method according to at least one of claims 6 to 14, characterized in that for the preparation of the mixture, the at least one active substance is added in particulate form.

16. The method according to claim 15, characterized in that particles are used which have a diameter which is smaller than the mean pore diameter of the carrier layer and at least 1/3 (33%) of the average pore diameter.

17. The method according to claim 15 or 16, characterized in that particles are used with a diameter <500 [im.

18. The method according to claim 17, characterized in that particles are used which have a diameter between 100 μιη and 300 im.