WO2009098725A2

WO2009098725A2 - Cleaning cloth

Info

Publication number: WO2009098725A2
Application number: PCT/IT2009/000029
Authority: WO
Inventors: Mirko Gamenoni
Original assignee: Toscana Non Tessuti S.R.L.
Priority date: 2008-02-06
Filing date: 2009-02-03
Publication date: 2009-08-13
Also published as: ITFI20080018A1; WO2009098725A3

Abstract

A cleaning cloth comprising at least one base layer (B) consisting at least partly of cellulose-based staple fibres and having a first face and a second face; at least one first covering layer (A) associated with the first face of said base layer (B); and at least one second covering layer (C) associated with the second face of said base layer (B).

Description

"CLEANING CLOTH"

DESCRIPTION Technical field

The present invention concerns a multilayer cleaning cloth, particularly but not exclusively for domestic use, able to absorb liquids and retain dirt, and a relative production method. State of the art

In the cleaning sector the production of multilayer cloths is known, in which each layer comprises non-woven material partly differing from one layer to the other, to give the finished product particular properties.

The cloth can therefore include different layers in order to balance the properties of the finished product, for example softness, flexibility, tenacity, absorbency, the ability to retain liquids, tensile strength and abrasion resistance or other. Object and summary of the invention

The object of the invention is the provision of a cloth for cleaning surfaces with improved properties, which is particularly effective in use, and a relative manufacturing method.

These objects and advantages are achieved substantially by a cloth as claimed in claim 1 and by a method for the production thereof as claimed in claim 17.

The subject of the invention is a cleaning cloth comprising at least one base layer of non-woven fabric consisting at least partly of cellulose-based staple fibres and having a first face and a second face; at least a first covering layer associated with the first face of said base layer and at least a second covering layer associated with the second face of said base layer.

In the context of the present invention and the attached claims, by

"associated covering layer" a layer is intended, which can include further intermediate layers or if necessary in which said further intermediate layers are overlaid; in short, the cloth can consist of a plurality of covering layers one on top of another.

The term "cellulose-based staple fibres" includes fibres produced by cutting continuous fibres obtained via a cellulose spinning process.

Said spinning process involves - in short - producing filaments in the liquid state which are passed through the capillary holes of a spinneret; said filaments are then coagulated and solidified according to various processes for producing continuous fibre.

In a particularly advantageous embodiment of the invention, the cellulose-based staple fibres are viscose fibres; however, said cellulose fibres can be at least partly of another type, for example cupro, modal or other fibers.

Viscose, also called "artificial silk", is used in general in the form of continuous fibres spun to produce various products (for example fabrics for garments or furnishing upholstery) which have a very soft hand, like silk, and are at the same time very inexpensive. It is generally produced from wood cellulose or cellulose from other vegetable sources such as trees or cotton or straw, treated with a solution of caustic soda; carbon sulphide is then added to form cellulose xanthogenate, which is further dissolved with more caustic soda. The colloidal solution thus formed is extruded and the filaments produced by the spinneret form the viscose fibres.

Advantageously, the cellulose fibres in the base layer have a length varying from 10 mm to 100 mm or more and denier of less than one; in this way it is possible to give the finished product a particular softness and at the same time very high liquid and oil absorption qualities.

It should be noted that by increasing the number and reducing the denier (den) of the cellulose fibres in the base layer, the liquid and oil absorbency of the finished product increases, since the number and surface of the fibres in contact with the liquid inside said layer increases. In one embodiment of the invention, the base layer consists 100% of cellulose fibres, resulting in a finished product with particularly good characteristics in terms of softness and liquid absorption capacity.

In further advantageous embodiments, the base layer advantageously consists of cellulose fibres in combination with fibres of other types in varying quantities according to working or utilisation requirements.

In the latter case, in the base layer the cellulose fibres are advantageously and preferably preponderant with respect to any fibres of other types.

In particular, the base layer can comprise fibres of one or more different types to increase some characteristics or properties of the finished product, as described below.

The first covering layer and the second covering layer are permeable to liquids (i.e. suitable for the passage of water) and are advantageously and preferably made of copolymer latex or foam so as to obtain a particularly tenacious covering resistant to numerous chemical agents (except for particularly aggressive solvents); the finished cloth can therefore be washed and re-used numerous times.

According to another aspect, the invention concerns a method for producing a multilayer cleaning cloth, which comprises at least the following steps:

- producing a base layer made of non-woven fabric comprising at least partly cellulose-based staple fibres and having a first face and a second face;

- applying to the first face and to the second face a first and a second covering layer respectively.

In one embodiment of the invention, the base layer (both when made entirely of cellulose fibres and when made of a combination of cellulose fibres and fibres of other types) is produced by means of carding and needlefelting, so as to give the finished product a very marked softness in a simple and inexpensive way.

In short, "carding" is an operation which is part of the process of spinning or - more generally - of the formation of a textile support and consists in freeing from impurities, disentangling and making parallel the textile fibres also of several different layers to permit subsequent operations such as spinning or needlefelting.

"Needlefelting" is the process by which, by vertical movement of the needles of a needlefelting machine, compactness is given to the web of fibres obtained at the outlet of a carding machine, by overlaying several layers of web. Needlefelting can also be of the water type (hydroentangling), which uses very fine jets of water at high pressure instead of needles. In any case, a fabric with a certain texture is obtained due to penetration of part of the fibres vertically shifted by the movement of the needles or the jets of water. Subsequently, to increase the resistance of the product, further processes can be performed, such as resin finishing or heat-setting. Obviously production of the base layer can involve operations other than carding or needlefelting. For example, heat-setting can be performed by means of low-melting synthetic fibres or by means of specific chemical additives; the latter cases, however, result in degradation of the characteristics of the finished product, which can furthermore have a higher environmental impact (the chemical additives used for heat-setting are generally not easily biodegradable).

The covering layers are advantageously and preferably applied on the base layer by means of impregnation or by means of coating, with dyes if necessary.

By "impregnation" a textile process is meant, for application of a covering layer of a certain thickness on a base layer in the form of a strip, which consists in application of materials in the form of more or less fluid pastes or foams on the base layer. In particular, the impregnation can be performed by means of a padding mangle for textile impregnation that comprises two rotating cylinders through which the base layer in the form of a strip is passed and on which the covering material (foam or other) is applied; a binder can be provided if necessary in said covering material. The covering material is therefore deposited on the base layer running between the impregnation cylinders.

By "coating" a textile process is understood, for the formation of a covering layer of a certain thickness on a base layer in the form of a strip, which consists in the continuous application of materials in the form of more or less fluid pastes or foams on the base layer followed by a finishing treatment (polymerisation, wrinkle-resistant finish or other). In general, coating is performed by means of roller coating machines which permanently adhere the covering layer to the base layer; appropriate adhesive substances can be used for better adhesion between the base layer and the covering layer.

Obviously the above-mentioned methods for production or application of the various layers can vary according to particular applications or particular fibres used.

Advantageously, further means can be adopted in order to increase the surface tension of the base layer so that the covering material (latex, foam or similar) does not spread to the inside of said base layer, avoiding deterioration of the characteristics of the finished product.

A particular advantage of the present invention is the high quality of the finished product. In fact, it has a high cleaning and degreasing power, also without the use of detergents, in combination with a high level of softness. Furthermore, if the covering material is latex or foam, deposit of the covering material is of high quality and uniform; the appearance of the finished product is therefore also improved, since its optical characteristics are improved, for example lustre and shine.

A further advantage is that it is easy to provide different types of cleaning cloth according to the invention depending on the specific surfaces to be cleaned, providing within the base layer an appropriate combination of viscose fibres and fibres of other types. It is therefore possible to optimise the finished product according to particular uses.

A further advantage is that the production process is simplified, since it is not necessary to comprise the viscose fibres in the covering layers, at the same time obtaining a finished product of considerable efficiency and effectiveness. Furthermore, it is not strictly necessary to provide materials or substances to bind the fibres together inside the base layer.

A further advantage is given by the fact that the above-mentioned cleaning cloth has an excellent level of biodegradability, since it is made of large quantities of viscose cellulose fibre - in particular when the base layer consists of 100% viscose - a characteristic that is increasingly required by the current market.

A further advantage is that the cleaning cloth according to the invention can be produced using traditional machines; it is therefore easy to produce with machines of said type.

In short, the cloth according to the invention is simple and inexpensive to produce and particularly versatile and efficient in use.

Further advantageous characteristics and embodiments of the method and product according to the invention are indicated in the attached dependent claims and will be further described below with reference to some non-limiting embodiments. Brief description of the drawings

The present invention can be better understood and its numerous objects and advantages will be evident to a person skilled in the art with reference to the schematic drawing attached, which shows a practical non- limiting exemple of the invention.

In particular Figure 1 shows a schematic vertical section of a cleaning cloth according to an embodiment of the invention.

Detailed disclosure of some embodiments of the invention

The cloth is indicated by 1 in Fig. 1 and has a base layer B with a first face B1 and a second face B2, with which a first covering layer A and a second covering layer C are associated respectively. In a particularly advantageous embodiment of the invention, the base layer B is made entirely of viscose-based staple fibres.

Advantageously, the first and second covering layer A and C can be made of one or more latexes or foams of copolymers in variable ratios, for example in a ratio from approximately 0:100 to 100:0 when made with two elements (latex and/or foam); vulcanising pastes or dyes can be used if necessary according to particular technical or aesthetic and use requirements.

The above-mentioned copolymers can be acrylic, polyurethane or styrene-butadiene (SBR), nitrile-butadiene (NBR) or polylactic acid (PLA) or other. In particular, the polylactic acid (PLA), which is a copolymer derived from maize, in the form of a foamable emulsion is a particularly advantageous form of application with the cloth according to the invention, since it makes the finished product fully biodegradable (when the base layer is 100% viscose).

The first and second covering layers A and C may be made of at least partly different materials, according to particular use requirements.

In another advantageous embodiment of the invention, the base layer

B consists of at least 70% viscose fibre and the remaining 30% of synthetic microfibres, i.e. fibres with denier less than one and of the type comprising molecules obtained by synthesis; the covering layers A and C can be substantially the same as those described above.

In particular, the synthetic microfibres can be one or more of the following: polyester, nylon, polypropylene, acrylics, polylactic acid or other.

It should be noted that in the latter case, polylactic acid is in the form of microfibre and not emulsion. More specifically, a base layer B can be produced comprising approximately 70% viscose fibre and approximately 30% polyester microfibre so as to increase the tenacity of said base layer B and produce a finished product particularly suitable for cleaning very textured or rough surfaces such as terracotta floors. In fact, the covering layer may not be sufficient to provide the necessary tenacity for the cloth on these surfaces.

The base layer B could obviously comprise viscose fibres in combination with synthetic microfibres according to different ratios and variable quantities depending on specific working or use requirements. For example, the viscose fibres and the synthetic microfibres can be in a ratio from 100:0 to 50:50 in weight with respect to said base layer B.

In any case, the base layer B, made entirely or only partly from viscose fibres, preferably has a weight per square unit ranging from 50 g/m² to 500 g/m². The above-mentioned viscose microfibres and any synthetic microfibres can be in various sizes, preferably from approximately 10 mm to approximately 100 mm, preferably from approximately 30 mm to 60 mm, and can have deniers varying from approximately 0.5 deniers to approximately 1 denier. The above-mentioned cleaning cloth can be used for cleaning by hand on any type of surface; it can also be used as an accessory on a cleaning machine.

It is understood that the illustration provided herein represents only a possible non-limiting embodiment of the invention, which can vary in forms and arrangements without departing from the scope of the concept underlying the invention. Any presence of reference numbers in the attached claims has the sole purpose of facilitating the reading thereof in the light of the preceding description and accompanying drawings and does not limit the scope of protection of the claims.

Claims

1) A cleaning cloth characterised by comprising: at least one base layer (B) consisting at least partly of cellulose-based staple fibres and having a first face (B1) and a second face (B2); at least one first covering layer (A) associated with said first face (B1) of said base layer (B); and at least one second covering layer (C) associated with said second face (B2) of said base layer (B).

2) Cleaning cloth as claimed in claim 1 , characterised in that said base layer (B) is a non-woven fabric made at least partly of said cellulose- based staple fibres.

3) Cleaning cloth as claimed in claim 1 and/or 2, characterised in that said cellulose-based staple fibres are at least partly viscose fibres.

4) Cleaning cloth as claimed in at least one of the preceding claims, characterised in that said cellulose-based staple fibres have varying sizes.

5) Cleaning cloth as claimed in at least one of the preceding claims, characterised in that said cellulose-based staple fibres have deniers (den) of less than one.

6) Cleaning cloth as claimed in at least one of the preceding claims, characterised in that said base layer (B) is made entirely by cellulose-based staple fibres.

7) Cleaning cloth as claimed in at least one of the claims from 1 to 5, characterised in that said base layer (B) is made of cellulose-based staple fibres in combination with further fibres in a varying ratio. 8) Cleaning cloth as claimed at least in claim 1 and/or 7, characterised in that said cellulose-based staple fibres are preponderant with respect to said further fibres within said base layer (B).

9) Cleaning cloth as claimed in at least one of the claims 7 and/or

8, characterised in that said further fibres are synthetic microfibres of one or more different types in order to increase some characteristics or properties of said cleaning cloth (1), for example microfibres of polyester, nylon, polypropylene, acrylics, polylactic acid or other.

10) Cleaning cloth as claimed in at least one of the claims from 7 to

9, characterised in that said base layer B is made of approximately 70% of cellulose-based staple fibres and approximately 30% of further fibres.

11) Cleaning cloth as claimed in at least one of the claims from 7 to 10, characterised in that said base layer (B) comprises a combination of cellulose-based staple fibres and of said further fibres suitable for increasing the tenacity of said base layer (B) so that said cleaning cloth (1) is particularly suitable for use on very textured or rough surfaces.

12) Cleaning cloth as claimed in at least one of the preceding claims, characterised in that said base layer (B) has a weight per square unit from approximately 50 (g/m²) to approximately 500 (g/m²). 13) Cleaning cloth as claimed in at least one of the preceding claims, characterised in that said cellulose-based staple fibres and if necessary said further fibres have varying sizes and deniers, for example lengths from approximately 10 (mm) to 100 (mm) or more, or preferably from approximately 30 (mm) to approximately 60 (mm), and deniers from approximately 0.5 (den) to approximately 1 (den).

14) Cleaning cloth as claimed in at least one of the preceding claims, characterised in that said first covering layer (A) and/or said second covering layer (C) are permeable to water.

15) Cleaning cloth as claimed in at least one of the preceding claims, characterised in that said first covering layer (A) and/or said second covering layer (C) are made of latex or foam, for example acrylic foam, styrene- butadiene (SBR)₁ nitrile-butadiene (NBR), polylactic acid (PLA) or polyurethane or other; with vulcanising pastes and/or dyes or other if necessary. 16) Cleaning cloth as claimed in at least one of the preceding claims, characterised in that said first covering layer (A) and/or said second covering layer (C) can be made with at least two copolymer foams in ratios varying from 0:100 to 100:0.

17) Method for producing a multilayer cleaning cloth (1) which comprises at least the following steps: producing a base layer (B) comprising at least partly cellulose- based staple fibres and having a first face (B1) and a second face (B2); applying to said first face (B1) and to said second face (B2) a first and a second covering layer (A; C) respectively. 18) Method as claimed in claim 17, characterised in that said base layer (B) is produced by carding and needlefelting or similar.

19) Method as claimed in claim 17 and/or 18, characterised in that said covering layers (A; C) are applied on said base layer (B) by means of impregnation or coating, with dyes or other if necessary.

20) Method as claimed in at least one of the claims from 17 to 19, characterised in that said base layer (B) is produced partly or entirely with viscose-based staple fibres in varying sizes and with deniers (den) of less than one.