MXPA99004634A - Embossed wet-laid fibrous structures - Google Patents

Abstract

The use of a repeating embossing pattern on a wet-laid cellulosic fibrous structure (10) is described to improve the cleaning performance of said cellulosic fibrous structure (10), said embossing pattern being non-continuous in at least one diagonal direction and comprising non-equidistant discrete embossing sites (14), the cleaning performance index (CPI E) being not less than 105, wherein said index (CPI E) is represented in terms of the following equation CPI E=(CPV E - CPV R) x 100+100/CPV R. The cleaning performance index (CPI E) is preferably 110. In a preferred embodiment of the present invention, the embossing pattern is of an angular nature. In a more preferred embodiment of the present invention, the embossing pattern is in the form of a rhombus.

Description

STRUCTURES OF FIBERS TENDED IN HUMID, RECORDED IN HIGH RELIEF FIELD OF THE INVENTION This invention relates to the use of a design embossed in high relief on a structure of cellulose fibers, wet laid, for a superior response in cleaning tasks. The present invention has particular application in cellulosic fiber structures that can be used for the cleaning of areas of the human body, for example dry towels of paper for perfumery, paper towels, disposable facial tissues, articles for the care of the skin for purposes cosmetic and therapeutic and dry towels; for cleaning other surfaces, for example, kitchen and bathroom surfaces; and for surfaces that require cleaning in the industry, for example, surfaces in machinery or vehicles. For simplicity, the following description focuses on cellulose fiber structures, such as towels and tissues for perfumery to be applied to human skin, but the foregoing should be understood in the light of the above comments regarding the broadest possibility of application of the present invention.

BACKGROUND OF THE INVENTION The cellulosic fiber structures engraved in high relief are well known in the art and are a product of general consumption of everyday life. The cellulosic fiber structures are formed, in general, by superimposed sheets. Normally, the engraving is carried out by means of one of two processes; mainly, engraved enea ble where the protuberances of one roller are intermeshed between the protuberances of another roller; and protruding projection with projection wherein the protrusions on axially parallel rollers, juxtaposed to form a point of contact between them, are made to coincide with the protuberances on the opposite roller. U.S. Patent Nos. 4,325,773, 4,487,796, 3,940,529, 3,414,459, 3,547,723, 3,556,907, 3,708,366, 3,738,905, 4,483,728 and 3,867,224 illustrate cellulose fiber structures engraved in high relief, which comprise engravings of type either detachable or projecting with projection , on the sheet that constitutes them. Furthermore, Patents Nos. 5,294,475 and 5,468,323 of the United States show a recorded cellulosic structure and an improved apparatus and process for making these engraved cellulose structures. It has been recognized that the sheets are engraved for the two aesthetic purposes: to maintain the sheets in a face-to-face relationship and to provide space between the sheets for a thicker thickness and a quilted appearance similar to the fabric, so that the consumer A product is presented that has a quality appearance and does not allow the separation of the sheets during use. However, none of the aforementioned patents exploits the use of a wet laid cellulosic fiber structure comprising a particular design for a superior and improved response in cleaning tasks. Surprisingly, it has thus been discovered in the present invention, that the use of a wet laid cellulose fiber structure, with a non-continuous repeat pattern in at least one diagonal direction, can be instinctively exploited by a consumer for an improvement exemplary in cleaning tasks, without compromising the basic attributes of fiber structure of tensile strength, bond strength, absorbency and softness. As a result of this improved cleaning performance, the use of the material is significantly improved and a high level of satisfaction and consumer confidence is achieved. The performance in cleaning tasks can, in fact, be measured and expressed in terms of a cleaning performance index. For the wet laying cellulosic fiber structure comprising the particular design of the present invention, P817 typically values exceeding 105.

SUMMARY OF THE INVENTION The use of a high relief engraving design on a wet laid cellulose fiber structure is described. The engraved design is discontinuous in at least one diagonal direction and comprises discrete engraving sites, not equidistant. The performance in cleaning tasks of the cellulosic fiber structure can be measured and expressed in terms of an index, the index is not less than 105 and preferably is 110. The index is represented in terms of an equation. In a preferred embodiment of the present invention, the engraved design is angular in nature. In a more preferred embodiment of the present invention, the engraved design is diamond-shaped. Normally, the cellulosic fiber structure comprises at least two sheets. Each of the sheets comprises discrete engraved sites and essentially continuous non-engraved regions; each of the discrete engraved sites of a sheet is oriented towards the non-engraved region of the opposite sheet.

BRIEF DESCRIPTION OF THE DRAWINGS OR FIGURES It is considered that the invention will be better understood from the following description taken in the form P817 together with the accompanying drawings, wherein: Figure 1 is a fragmented vertical sectional view of the wet cellulosic fiber laying structure, in accordance with the present invention; and Figure 2 is a plan view of the most preferred etching design, in the wet laying structure of cellulose fiber.

DETAILED DESCRIPTION OF THE INVENTION As used herein, the term "high relief engraving" refers to the process of deflecting a relatively small portion of a normal cellulosic fiber structure with respect to its plane and striking the projected portion of the fiber structure cellulose against a relatively hard surface, to permanently undo fiber to fiber links. The engraving typically results in a localized permanent deformation of the "engraved site" that has been deflected in this manner. The etched site is normally projected towards the plane of the cellulosic fiber structure and towards the opposite sheet. As used herein, the term "discrete" means non-contiguous.

Structures of cellulose fiber Structure 10 of cellulose fiber, of P817 according to the present invention is macroscopically two-dimensional and planar, although not necessarily planar. The cellulosic fiber structure 10 has some thickness in the third dimension. The third dimension is, however, relatively small compared to the first two real dimensions or with the ability to make a cellulosic fiber structure 10 with relatively large dimensions in the first two dimensions. Figure 1 shows a fragmented view in vertical section of a cellulosic fiber structure 10 of the present invention, comprising at least two sheets, mainly sheet 11 and sheet 12. Each of the sheets 11 and 12 comprise two distinct zones, essentially unbroken continuous regions 13, and discrete engraving sites 14, which project generally outwardly of the structure and, preferably, orthogonal to it. Each discrete engraved site 14 of a sheet 11, 12 is oriented towards the unlabeled region 13 of the opposite sheet 11, 12. The uncut regions 13 and the engraved sites 14 of each sheet 11, 12 are composed of approximate fibers by linear elements. The fibers are components of the cellulosic fiber structure 10 having a relatively large dimension (along the longitudinal axis of the fiber), compared with the other two relatively small dimensions (perpendicular to each other, and which are both radial and perpendicular to the fiber). longitudinal axis of the fiber), so that the linearity is approximate. While the microscopic examination of the fibers can reveal two other dimensions that are small compared to the main dimension of the fibers, these other two dimensions do not need to be substantially equivalent or constant over the entire axial length of the fiber. It is only important that the fiber be able to bend around its axis, be able to join other fibers and be distributed by means of a liquid carrier or by air. The fibers comprising the structure 10 of cellulosic fibers can be synthetic, for example polyolefin or polyester, they are preferably cellulosic, such as cotton wool, rayon or bagasse; and more preferably they are wood pulp, for example from soft woods (gymnosperms or conifers) or from hardwoods (angiosper as or deciduous). As used herein, a fibrous structure is considered "cellulosic" if the fibrous structure comprises at least about 50 volume percent cellulosic fibers, including but not limited to those fibers listed in the foregoing. It has been found that a cellulosic mixture of wood pulp fibers comprising softwood fibers, which have a length of 2.0 to about 4.5 millimeters, and with a diameter of about 25 microns to about 50 microns, and hardwood fibers with a length of less than about 1.0 millimeters and with a diameter of about 12 microns to about 25 micrometers, works well for the cellulosic fiber structures 10 described herein. If the wood pulp fibers are selected for the structures of cellulosic fibers, the fibers can be produced by any process to produce pulp, among which are included chemical processes such as sulfite, sulphate and soda processes.; and mechanical processes such as wood defibrated in stone. Alternatively, the fibers can be produced by combinations of chemical and mechanical processes or can be recycled. The type, combination and process of the fibers used are not relevant to the present invention. The hardwood and softwood fibers can be layered throughout the thickness of the cellulosic fiber structures.

Structures of wet laying cellulosic fibers In accordance with the present invention, the cellulosic fiber structure 10 is wet laid in accordance with the principles and machinery associated with the production of paper in the wet laying process; the fibers are first mixed with chemical elements and with water to obtain a uniform dispersion known as pulp, at very high dilutions of 0.01 to 0.5 percent by weight of the fiber. The fiber is then deposited in a wire mesh in motion, where the excess water is drained, leaving the fibers randomly distributed in a uniform pattern, which is then joined and terminated as required. The wefts are usually formed at speeds up to 300 meters per minute from textile fibers up to 2500 meters per minute for tissue paper made from pulp fibers.

Embossed design in high relief As is evident from Figure 1, the engraved sites 14 of the sheet 11 are not matched with the engraved sites 14 of the sheet 12. The engraved sites 14 of each sheet 11, 12 represent discrete regions of relatively high density, due to the compaction of fibers that occurs during engraving. The essentially unregistered regions 13 have a density less than that of the engraved sites 14, since the essentially unregistered regions 13 are not compacted in the etching process. The density of the essentially unregistered regions 13 approximates the density of the recorded discrete sites 14 before engraving starts. In accordance with the present invention, use is made of a repeated engraved design in a structure 10 of wet laying cellulosic fibers, to improve the performance that the structure 10 of cellulosic fibers has in the cleaning operation, the engraved design is discontinuous in at least one diagonal direction and comprises engraving sites 14, discrete, not equidistant. Being "non-continuous", there is an interruption in the equidistant separation of the engraving sites 14 on the plates 11, 12. As used herein, the term "repeating" means that the design is formed more than once in the cellulosic fiber structure 10. The engraved sites 14 of the cellulosic fiber structure 10 correspond to the topography of the apparatus used to make the cellulose fiber structure 10. A preferred embodiment of the present invention is that the engraving pattern or pattern is angular in nature. A more preferred embodiment of the present invention is that the engraving is diamond-shaped. The most preferred embodiment is illustrated in Figure 2. However, any form is possible and the forms include, but are not limited to: polygons, semicircles, ellipsoids, etc., and any combinations thereof provided the pattern is a diagonal of repetition does not continue.

P817 Cleaning Performance Indexes As described above, a repeating etching pattern is used on the cellulosic fiber structure 10 in order to improve the performance of the structure 10 in a cleaning operation. Cleaning performance is expressed in terms of a CPIE index, the index is not less than 105 and preferably is 110. Table I indicates the results obtained from the tests where the performance in the cleaning of the DNE samples was measured. (samples with the preferred engraving pattern) and regular samples (samples with engraving but without pattern). A suitable method for allowing the calculation of the cleaning performance index for the cellulosic fiber structure 10 of the present invention is described later in the section "Description of the test procedure".

For all samples tested, the base weight P817 was 46.8 grams per square meter, the pressure applied in cleaning (in terms of weight) was 800 grams and the number of leaves involved in the cleaning action was 4. While these particular values were selected for the test, other values are equally possible. Twenty measurements were taken and the average values were tabulated in Table I above. The performance in cleaning tasks is a function of the removed grime, divided by the number of sheets used in the cleaning. For experimental purposes, a value of 0.8 grams is selected to represent the maximum amount of dirt that can be removed. In this way, for an ideal performance in cleaning tasks, the amount of grime removed is 0.8 grams and the number of sheets used by the consumer is 1, resulting in a cleaning performance value calculated for the DNE samples and for For the regular CPVE and CPVR samples, the CPIE cleaning performance index can be calculated. The CPIE cleaning performance index is represented in terms of the following equation: CPI, E. = - (aCPV_E - CPV.R -) * - x 100 + 100 CPVR where, CPIE is the index of cleaning performance of the structure of fibers 10.

P817 CPVE is the cleaning performance value of the fibrous structure 10; CPVR is the cleaning performance value of the fibrous structure 10 without the pattern of high relief engraving; and CPVE = dirt removed from the fiber structure 10 no. of fiber structure sheets 10 CPVR = muscle removed from fiber structure 10 without pattern no. of fiber structure sheets 10 without the pattern In the previous CPIE equation, a value of 100 is assumed for the cleaning performance index for the regular sample type. It is more evident from the results in Table I that the cleaning performance index for the CPIE samples is much greater than 100, that is, not less than 105 and preferably 110. This suggests that the consumer is more positively influenced by the presence of a pattern of engraving in particular on a structure 10 of cellulosic fiber.

DESCRIPTION OF THE TEST PROCEDURE A method is described here which delineates the procedure for calculating the cleaning performance index for the cellulosic fiber structure 10 of the present invention. The structure 10 of cellulosic fiber is considered to be a sheet of sanitary tissue paper.

P817 Methodology for mechanical cleaning 1.1. Materials 1.1.1 DC-fix metallic foil 1.1.2 Light gray cardboard is used as a cushion for the DC-fix metal foil; 1.1.3 Artificial fecal matter (Feclone BFPS 6, 1.3 percent early solution) 1.1.4 Glass bottle with lid (dimensions: 75 millimeters X 75 millimeters); 1.1.5 Storage bag (block of measures: 80 mm X 80 mm); 1.1.6 Speed control equipment (motor); 1.1.7 Balance for weighing. 1. 2 Procedure 1.2.1 Prepare artificial faecal material following the manufacturer's instructions. (It is very important to observe that the mass should be cooled to room temperature without mechanical help, for example with a mixer). 1.2.2 Adjust the weight of the slide to the appropriate weight for the tissue paper. 1.2.3 Take the weight of four sheets of tissue paper and tabulate it.

P817 .2.4 Place the four sheets in a stack at the bottom of the slide and connect the row with the speed control equipment. 1.2.5 Place the prepared slide horizontally on its side. 1.2.6 Place the slide on the scale to weigh and apply 0.8 grams of artificial faecal material. Clean the dough directly from the slide to a box marked on the DC-fix metal foil. 1.2.7 Apply the glass bottle to the dough and make circular movements (5 times) to spread the dough to a diameter of approximately 30 to 40 millimeters. Do this without applying extra pressure to the glass. 1.2.8. Apply a weight of 1000 grams directly in the middle of the glass jar and close with lid. After 5 seconds, push the glass bottle with the weight on the dough without applying any additional pressure. Place two fingers on the back of the glass jar and push the glass bottle with these fingers towards yourself (spread within 5 seconds). 1.2.9 Remove the weight and the glass jar. 1. 2.10 Push the dough all the way back into the box marked on the DC-fix metal foil using the sharp edge of the glass jar. Push from the bottom and top. 1.2.11 Take the glass jar and apply it to the dough. Place the glass jar directly before the edge of the DC-fix metal sheet without applying any additional pressure to the glass jar. 1.2.12 Leave the slide for 5 seconds. 1.2.13 Turn on the speed control equipment and move the glass bottle through the mass using a speed of 7.8 centimeters per second. 1.2.14 Stop the machine after a sweeping distance of 10 centimeters 1.2.15 Leave the slide for 5 seconds. 1.2.16 Take the weight of tissue paper and tabular tissue. Note: Clean the DC-fix metal foil after each measurement. Mix artificial fecal material before placing it on the slide.

GLOSSARY Structure of cellulose fibers, 12 Plate Region not engraved in high relief. Sites recorded in high relief 7

Claims (6)

1. CLAIMS 1. Use of a pattern of repetition of engraving in high relief on a structure of cellulosic fibers of wet laying to improve the cleaning performance of the cellulosic fiber structure; the pattern of high relief engraving is non-continuous in at least one diagonal direction and comprises discrete engraving sites in high relief, not equidistant; the cleaning performance index is not less than 105, where the index is represented in terms of the following equation:
2. CPIE = (CPVE - CPVr) x 100 + 100 CPVR where, CPIE is the index of performance in cleaning the fiber structure; CPVE is the performance value in cleaning the fibrous structure; CPVR is the performance value in cleaning the fibrous structure without the pattern of high relief engraving; Y
3. CPVE = dirt removed from the fiber structure no. of fiber structure sheets
4. CPVR = dirt removed from the fiber structure (10) without pattern no. of fiber structure sheets without the pattern 2. Use of a high relief engraving pattern according to claim 1, wherein the cleaning performance index is preferably 110. 3. Use of a high relief engraving pattern according to Claim 1, wherein the pattern of high relief engraving is angular in nature. 4. Use of a high relief engraving pattern according to claim 3, wherein the high relief engraving pattern is diamond-shaped.
5. 5. Use of a high relief engraving pattern according to claim 1, wherein the cellulosic fiber structure comprises at least two sheets.
6. 6. Use of a high relief engraving pattern according to claim 5, wherein each of the sheets comprises discrete sites of engravings and essentially continuous non-engraved regions, each of the discrete engraved sites of the sheet being oriented towards the region not engraved from the opposite sheet. P817