FR2983394A3 - SPONGE COMPRISING A VEGETABLE SPONGE TISSUE LAYER - Google Patents

Abstract

The invention relates to a sponge (10) comprising at least one layer of vegetable sponge (12) attached to a layer of hydrophilic synthetic foam (14). An abrasive surface (16) may at least partially cover one side of the synthetic foam layer (14). Alternatively, two layers of vegetable sponge cloth are attached to the hydrophilic synthetic foam layer (14).

Description

The present invention relates to a sponge, in particular a scouring sponge, comprising a layer of vegetable terry cloth.

Scouring sponges are particularly known having a sponge portion for absorbing liquids and an abrasive portion for scouring. The sponge portion for absorbing liquids is either synthetic sponge or vegetable sponge. The vegetable sponge (or cellulosic) is made by regeneration of cellulose fibers. However, these cellulose fibers are absorbent and hydrophilic. These cellulose fibers thus contribute to better absorption of liquid by the sponge portion. The wiping ability of this type of sponge is also very good. However, this type of sponge is relatively expensive to produce. In addition, the vegetable sponge has some weakness in terms of wear resistance. The method of manufacture of this type of sponge indeed tend to weaken the cellulose fibers that compose it. In addition, the vegetable sponge is not elastic in traction, and is therefore fragile in terms of tear resistance. The conventional synthetic sponge (or foam), particularly a polyurethane foam having a density of 20 to 30 kg / m 3, generally has poor wiping power. However, there are hydrophilic synthetic foams, that is to say with a capacitance of liquid capillary absorption so that when the foam is in contact with a liquid, it enters spontaneously into the foam. This capillary absorption power can be obtained by means of a high density foam, typically of the order of 80 kg / m3. However, the manufacturing cost of a synthetic foam being substantially proportional to its density, this solution is expensive. According to another solution, a hydrophilic foam is produced by a particular formulation and chemical process.

Indeed, synthetic sponges are polyurethane foams obtained by the chemical combination of reagents, mainly an isocyanate and a polyol. The chemical nature of polyurethane foams is primarily defined by the polyol used. Thus, the hydrophobic, conventional polyurethane foams are often based on hydrophobic polyols such as, for example, propylene-based polyols. On the contrary, by using hydrophilic polyols, such as for example polyethylene glycol, a hydrophilic polyurethane can be obtained. The wiping performance of low density hydrophilic synthetic foams (20 to 30 kg / m3) R: \ 33200 \ 33272 NIC \ 33272-111205-application tq filed.docx 1/11 05/12/2011 5:26 272 EURV 2, however, remain significantly lower than the wiping performance of the vegetable sponge. The object of the present invention is to provide a sponge not having the aforementioned respective disadvantages.

More particularly, the invention aims to provide a sponge resistant to wear, having a high liquid absorption capacity and good wiping performance and, preferably, a good scrubbing power, that is to say say a good scratching power. To this end, the present invention provides a sponge comprising at least one layer of vegetable sponge attached to a layer of hydrophilic synthetic foam. According to preferred embodiments, the sponge according to the invention has one or more of the following characteristics, taken alone or in combination: the layer of vegetable terry cloth has a fine cellular structure; the vegetable sponge layer has pores less than 1 mm in diameter; the vegetable toweling layer has a basis weight greater than 40 kg / m3; an abrasive surface at least partially covers one side of the synthetic foam layer; the abrasive surface is made by means of a nonwoven fabric impregnated with thermosetting resin, and preferably including abrasive fillers; the thickness of the vegetable sponge layer is from 3 to 12 mm, preferably from 4 to 6 mm; the synthetic foam layer has a capillary absorption rate of at least 0.10 g / cm 2, preferably at least 0.50 g / cm 2; the thickness of the hydrophilic synthetic foam layer is between 10 and 50 mm; the vegetable terry cloth layer extends mainly in a plane, the vegetable terry cloth layer having reliefs, distinct from the pores of the vegetable terry cloth layer, recessed or protruding from the extension plane; the sponge comprises a reinforcing grid, made of synthetic or vegetable material, incorporated in the thickness of the vegetable sponge layer; the hydrophilic synthetic foam layer has closed pores, preferably less than 0.7 mm in size; the hydrophilic synthetic foam layer has open pores, preferably larger than 1 mm; R: \ 33200 \ 33272 NIC \ 33272-111205-application tq deposited.docx 2/11 05/12/2011 5:26 272 EURV 3 - the layer of hydrophilic synthetic foam has a density greater than or equal to 25 kg / m3; the hydrophilic synthetic foam layer has a tensile strength greater than or equal to 120 kPa; the layer of hydrophilic synthetic foam has an elasticity greater than or equal to 200%; the vegetable sponge layer and the hydrophilic synthetic foam layer are fixed together by means of an adhesive having a viscosity greater than 10,000 mPa.s at 25 ° C., which adhesive is deposited at a rate of not more than 200 g / m2, preferably at most 150 g / m2; the hydrophilic synthetic foam layer comprises at least one recess adapted to facilitate the gripping of the sponge; Other features and advantages of the invention will appear on reading the following description of preferred embodiments of the invention, given by way of example and with reference to the appended figures. Figure 1 shows schematically an example of sponge. FIG. 2 represents a cross section of the sponge of FIG. 1. The sponge 10, as represented in FIGS. 1 and 2, comprises three layers 12, 14, 16 superimposed and glued in pairs by means of layers of adhesives 18, 20.

This sponge 10 has for example a thickness of between 20 and 50 mm, a length of between 9 and 15 mm and a width of between 5 and 10 mm. The sponge 10 here has a substantially parallelepiped shape. However other forms can be envisaged. In particular, the sponge 10 may have one or two sides forming corrugations to allow better grip of the sponge by a user. Other non-rectilinear shapes, more original and visually more attractive to consumers, can also be envisaged. In all cases, these forms are made in a known manner by correspondingly digging or cutting one or more of the layers 12, 14, 16 forming the sponge 10. The first layer 12 is a layer of vegetable or cellulosic sponge cloth.

This type of terry cloth has superior qualities of capillary absorption and wiping. This layer of vegetable sponge cloth 12 preferably has a thickness of between 3 and 12 mm, preferably less than 10 mm, more preferably between 4 and 6 mm. Indeed, the layer of vegetable sponge cloth must be large enough to allow wiping and absorbing liquids. However, the thickness of this layer of vegetable sponge cloth 12 must be limited to avoid premature wear of this layer of vegetable sponge 12. The layer of R: 333200333272 NIC \ 33272--111205- application tq filed.docx 3 / 11 05/12/2011 5:26 272 EURV 4 vegetable sponge fabric may have a density of between 40 and 80 kg / m3, preferably substantially equal to 50 kg / m3. To prevent premature wear of the layer of vegetable sponge cloth, it can be reinforced, for example by means of a reinforcing grid. This reinforcing grid may be synthetic material or plant material. This reinforcing grid may in particular comprise cellulose fibers. The reinforcing grid is preferably incorporated into the thickness of the vegetable toweling layer. The vegetable terry cloth layer has a fine cellular structure, that is to say it has pores with a diameter of less than 1 mm, in order to ensure good capillary absorption capacity of the fabric layer vegetable sponge. There are indeed two types of vegetable sponges: - the vegetable sponge with irregular porosity, containing pores that can measure a few millimeters, and - the vegetable sponge with fine porosity, whose pores have a diameter of less than 1 mm, usually encountered in the form of wiping cloths or sponges. A fine porosity has a double advantage in terms of absorption and wiping: on the one hand, the fine porosity sponge contains more cellulose (which are the absorbing fibers) and fewer holes. On the other hand, thanks to its fine porosity, the sponge with a fine porosity has a higher capillary power. Finally, the fine cellular structure corresponds to a superior wiping performance since the absorbed water is less easily springing out of the holes and leaves less traces on the wiped support. In addition, the vegetable sponge of irregular porosity has weights (dry weight relative to the wet volume) of the order of 30 kg / m3, while the vegetable sponge of fine porosity is about twice as dense. Such a density is suitable for vegetable-type products (thickness of the order of 5 mm), but it lends itself less to sponges of greater thickness (of the order of 20 mm or more) because of the lack of flexibility resulting from high density and cost. The vegetable terry cloth layer may extend primarily in a plane.

In this case, the layer of vegetable terry cloth may have reliefs, distinct from the pores of the vegetal sponge layer, hollow or protruding, relative to the extension plane. These reliefs can in particular help to accentuate the cleaning power of the sponge. These reliefs can be obtained in the following manner: the first step of manufacturing the cellulosic sponge consists in transforming the cellulose into viscose. Then, it is added grains of salt, pigments and possibly reinforcing fibers. The pasty mass thus obtained is then layered on a carpet in relief, then coagulated for example by heat. 272 EURV (steam). The cellulose fibers are regenerated, the melted salt grains give way to voids that determine the porosity of the sponge and the conveyor belt prints its relief on the surface of the sponge. The second layer 14 is a layer of hydrophilic synthetic sponge (or foam), in particular a layer of hydrophilic polyurethane foam. Hydrophilic synthetic polyurethane foams and processes for obtaining such foams are known to those skilled in the art and are described in particular in US-B-4,051,081, US-B-3,873,476, GB-A-1,429,711 and US-B. -6271277. By sponge or "hydrophilic" foam is meant, in the present text and in the claims, a sponge or a foam having a layer of thickness equal to 20 mm has a capillary absorption rate greater than 0.10 g / cm 2, preferably greater than 0.50 g / cm 2. In other words, a sponge or hydrophilic foam is a foam or sponge with a layer of thickness equal to 20 mm has an absorption rate by capillarity: - greater than or equal to 0.10 g / cm 2 and strictly less than 0.50 g / cm 2, or - greater than or equal to 0.50 g / cm 2. This measurement of the absorption rate by capillarity is carried out according to the following procedure: - a material sample, of given thickness, is immersed in city water for 3 minutes - then rinsed and pressed three times once manually out of the water; the sample is then filtered off for 3 minutes; the weight Pi of the sample is then weighed; the flat surface S of the sample is measured; - In a tray 6 mm in height with a stream of water running, the sample is laid flat for 15 s; the sample is removed from the tank and the weight is then weighed. the capillary absorption level defined for the thickness e of the sample is determined to be equal to: P2 PI -Cabs -S The hydrophilic synthetic foam layer may exhibit a breaking strength, measured according to the ISO standard 1798, fourth edition (ie ISO 1798: 2008), substantially equal to 150 kPa or more. This reinforces the vegetable sponge layer to limit wear. The hydrophilic synthetic foam layer 14 preferably has a thickness of between 10 and 50 mm. R: \ 33200 \ 33272 NIC \ 33272-111205-application tq filed.docx 5/11 05/12/2011 5:26 (1) 272 EURV 6 The hydrophilic synthetic foam layer may be of high density, preferably greater than 25 kg / m3. Indeed, a foam of lower density, appears light compared to the layer of vegetable sponge cloth with which it is associated. Density is measured according to ISO 845, third edition (ie ISO 845: 2006). Finally, the hydrophilic synthetic foam layer has a value of elasticity, that is to say an elongation at break, equal to 200% or more. Elongation at break is also measured in accordance with ISO 1798, fourth edition (ie ISO 1798: 2008).

For a better grip, the hydrophilic synthetic foam layer may have one or more lateral recesses or lateral cavities 22a, 22b adapted (s) to facilitate the seizure of the sponge by the user. To do this, these recesses or cavities, dug in the hydrophilic synthetic foam layer, have a length of at least 2 cm, a height of at least 5 mm and a depth of at least 5 mm. These cavities may for example be made by grinding. The third layer 16 forms an abrasive surface. In this case, this third layer 16 is made by means of a nonwoven fabric impregnated with thermosetting resin, and preferably including abrasive fillers. These abrasive fillers may for example be iron filings, quartz, corundum, recycled glass, talc particles or fine plastic grains. In this case, the glue used in the glue layers 18 and 20 between the hydrophilic synthetic foam layer 14 and the vegetable sponge layer 12 and the abrasive surface layer 16, respectively, is a viscous polyurethane glue of viscosity. greater than 10,000 mPa.S at 25 ° C. This viscosity is measured according to ASTM D 4889 of 2004 (ie ASTM D 4889-04, published April 2004). Such an adhesive makes the various layers integral after polymerization. It should be noted that this type of glue is impervious to water. Therefore, it should be ensured that it only partially covers the two surfaces of the vegetable sponge layer and the hydrophilic synthetic sponge layer to be bonded, in order to allow the passage of water between these two layers. As these layers of vegetable sponge and hydrophilic synthetic sponge have a honeycomb structure, the desired result can be achieved by: - depositing the glue with a roller rather than spraying; and / or in R: \ 33200 \ 33272 NIC \ 33272-111205-application tq filed.docx 6/11 05/12/2011 5:26 272 EURV 7 using a sufficiently viscous adhesive, in particular with a viscosity greater than 10 000 mPa at 25 ° C, as mentioned above, and limiting the amount deposited for example to 150 g / m2. Thus, the glue is deposited mainly on the projecting parts of the surface without penetrating deep or completely cover the cells. The presence in the hydrophilic synthetic sponge layer of large cells, in particular larger than 1 mm, makes it possible to obtain this effect. Alternatively, the layers are fixed together by thermal fusion on the surface of one of the bonded layers.

In the sponge 10 as described above, the lower layer of vegetable terry cloth effectively wipes the wet surfaces with which it is in contact. In addition by using a hydrophilic synthetic material in contact with the layer of vegetable sponge fabric, the capillary power of the layer of vegetable sponge is relayed by the intermediate layer which will also act as a reservoir.

In other words, the liquid first absorbed by the vegetable sponge layer is diffused into the intermediate layer of synthetic sponge which stores this liquid. The layer of vegetable sponge cloth saturates less quickly and it is therefore possible to wipe longer with the sponge without wringing it. To accentuate the "reservoir" effect of the hydrophilic synthetic foam, it may have a closed pore (or cell) structure. In particular, such a hydrophilic synthetic foam with closed-pore structure can better retain the detergent foam, and longer compared to a vegetable sponge whose fibrous structure does not allow long detain the detergent. This optimizes the washing capacity of the sponge and the consumption of detergent.

However, in this case, the sponge 2 has a hydrophilic synthetic foam layer with irregular porosity. In other words, the synthetic foam has: i) pores or cells of reduced size, that is to say of the order of a few tenths of a millimeter and preferably less than 0.7 mm, generally closed. These small cells promote absorption by capillarity. ii) pores or cells of larger sizes, that is to say of the order of one to a few millimeters and preferably from one to five millimeters, generally open. These cells of larger sizes facilitate the exchange of liquid between the layer of vegetable sponge and the layer of synthetic foam, through the layer of glue that does not completely cover them.

In addition, the vegetable sponge layer is flexible when wet. Dry, it shrinks and hardens. The abrasive surface layer bonded to the synthetic sponge layer is, for its part, not very extensible. The synthetic foam R: \ 33200 \ 33272 NIC \ 33272-111205-application tq filed.docx 7/11 05/12/2011 5:26 272 EURV 8 is a very elastic material. This foam acts as a mechanical buffer between the layer of vegetable terry cloth and the abrasive surface layer which are not very elastic. This avoids a succession of tensions and releases at the bonding surface of the vegetable sponge layer and the abrasive surface layer, this succession of tensions and releases causing, in the sponges of the prior art, detachments different layers. Of course, the present invention is not limited to the examples and to the embodiment described and shown, but it is capable of numerous variants accessible to those skilled in the art.

In particular, the third layer may, alternatively, be replaced by a second layer of vegetable or cellulosic sponge cloth, or even by a layer of vegetable or cellulosic sponge. The sponge thus formed has a high absorbency on two opposite sides and a better wear resistance than a conventional cellulosic sponge due to the presence of a layer of intermediate hydrophilic synthetic foam between the two layers of terry cloth plant, respectively between the layer of vegetable sponge and the vegetable sponge layer. Alternatively, the sponge may not have a third layer. In this case, it is possible to form the abrasive surface by direct printing on the second layer of terry cloth, by means of an ink comprising a binder based on a thermosetting compound and, preferably, abrasive fillers as described above. R: \ 33200 33272 NIC 33272-111205-application tq filed.docx 8/11 05/12/2011 5:26

Claims (18)

REVENDICATIONS1. A sponge (10) comprising at least one layer of vegetable sponge (12) attached to a layer of hydrophilic synthetic foam (14). The sponge of claim 1, wherein the vegetable sponge layer (12) has a fine cell structure. The sponge of claim 1 or 2, wherein the vegetable sponge layer has pores less than 1 mm in diameter. 4. Sponge according to one of claims 1 to 3 wherein the layer of vegetable sponge has a basis weight greater than 40 kg / m3. 5. Sponge according to one of the preceding claims, wherein an abrasive surface (16) at least partially covers one side of the synthetic foam layer (14). 6. Sponge according to claim 5, wherein the abrasive surface (16) is made by means of a nonwoven fabric impregnated with thermosetting resin, and preferably including abrasive fillers. The sponge of any preceding claim, wherein the thickness of the vegetable sponge layer (12) is from 3 to 12 mm, preferably from 4 to 6 mm. A sponge according to any one of the preceding claims, wherein the synthetic foam layer (14) has a capillary absorption rate of at least 0.10 g / cm 2, preferably at least 0.50. g / cm2. The sponge of any preceding claim, wherein the thickness of the hydrophilic synthetic foam layer (14) is 10 to 50 mm. A sponge according to any one of the preceding claims, wherein the plant sponge layer extends substantially in a plane, the layer of R: \ 33200 \ 33272 NIC \ 33272-111205-application tq filed.docx 9 / 11 05/12/2011 5: 26272 EURV 10 Vegetable terry cloth with reliefs, distinct from the pores of the vegetable terry cloth layer, recessed or protruding from the extension plane. 11. Sponge according to any one of the preceding claims, comprising a reinforcing grid, synthetic or vegetable, incorporated in the thickness of the vegetable sponge layer. 12. Sponge according to any one of the preceding claims, wherein the hydrophilic synthetic foam layer (14) has closed pores, preferably less than 0.7 mm in size. 13. Sponge according to any one of the preceding claims, wherein the hydrophilic synthetic foam layer (14) has open pores, preferably larger than 1 mm. 14. Sponge according to any one of the preceding claims, wherein the hydrophilic synthetic foam layer (14) has a density greater than or equal to 25 kg / m3. The sponge of any preceding claim, wherein the hydrophilic synthetic foam layer (14) has a tensile strength greater than or equal to 120 kPa. 16. Sponge according to any one of the preceding claims, wherein the hydrophilic synthetic foam layer (14) has an elasticity greater than or equal to 200%. The sponge of any of the claims, wherein the vegetable sponge layer (12) and the hydrophilic synthetic foam layer (14) are secured together by an adhesive (18) of viscosity greater than 10,000. mPa.s at 25 ° C, which adhesive is deposited at a rate of at most 200 g / m2, preferably at most 150 g / m2. 18. Sponge according to any one of the preceding claims, wherein the hydrophilic synthetic foam layer (14) comprises at least one recess (22a, 22b) adapted to facilitate the gripping of the sponge. R: \ 33200 \ 33272 NIC \ 33272-111205-application tq filed.docx 10/11 05/12/2011 5:26