KR20000053359A - Embossed wet-laid fibrous structures - Google Patents

Abstract

PURPOSE: Embossed cellulosic fibrous structures can be used for cleaning areas of the human person, for example, dry toilet tissue, paper towels, facial tissues, skin care articles for cosmetic and therapeutic purposes and dry wipes; for cleaning other surfaces, for example, kitchen and bathroom surfaces; and for surfaces which require cleaning in industry, for example, machinery or vehicle surfaces. CONSTITUTION: Use of a repeating embossing pattern on a wet-laid cellulosic fibrous structure(10) is provided to improve cleaning performance of the cellulosic fibrous structure(10), the embossing pattern being non-continuous in at least one diagonal direction and comprising non-equidistant discrete embossing sites(14), the cleaning performance index (CPIE) being not less than 105, wherein the index (CPIE) is represented in terms of the following equation: CPIE = ££(CPVE - CPVR)/CPVR| x 100| + 100, wherein CPIE is the cleaning performance index of the fibrous structure(10); CPVE is the cleaning performance value of the fibrous structure(10); CPVR is the cleaning performance value of the fibrous structure(10) without the embossing pattern; and CPVE = soil removed from the fibrous structure(10) DIVIDED no. of the fibrous structure(10) sheets CPVR = soil removed from the fibrous structure(10) without the pattern DIVIDED no. of the fibrous structure(10) sheets without the pattern.

Description

Embossed Wet-laid Fibrous Structures

Embossed cellulosic fibrous structures are well known in the art and are used in everyday life. Generally, cellulosic fibrous structures are formed by overlapping layers. Typically, nested embossing methods in which the projections of the roll mesh are present between the projections of the other rolls, and projections on the rolls parallel to the axis juxtaposed to form a nip between the projections. It is embossed by one of the knob-to-knob embossing methods that overlap with the projections on opposite rolls. US Patent 4,325,773, US Patent 4,487,796, US Patent 3,940,529, US Patent 3,414,459, US Patent 3,547,723, US Patent 3,556,907, US Patent 3,708,366, US Patent 3,738,905, US Patent 4,483,728, US Pat. No. 3,867,224, illustrates an embossed cellulosic fibrous structure comprising an embossed pattern or a knob-to-knob embossed pattern nested on a constituent layer. In addition, US Pat. No. 5,294,475 and US Pat. No. 5,468,323 teach embossed cellulosic structures, and improved methods and apparatus for making such embossed cellulosic structures. This layer is embossed to maintain the layer in a face-to-face relationship and to be spaced between the layers for both thicker calipers and quilted cloth-like appearance (both for aesthetic purposes) so that the appearance is good and the layers do not separate in use. It has been recognized to provide products to consumers.

Nevertheless, none of the aforementioned patents discloses the use of wet-laminated cellulosic fibrous structures that include unusual patterns for superior and enhanced cleaning reactions. Surprisingly, in the present invention, when using a wet-laminated cellulosic fibrous structure having a discontinuous repeating pattern in one or more diagonal directions, the tensile strength, the bond strength, the absorbency, and the flexibility of the fibrous structure can be cleaned without any compromise on the basic properties of the fibrous structure. It has been found that can be greatly improved. By this improved cleaning ability, the usefulness of the material is greatly improved, and at the same time, high satisfaction and reliability are provided to the consumer. In fact, the cleaning power can be measured and expressed as the cleaning power index. For wet-laminated cellulosic fibrous structures comprising the unique pattern of the invention, values greater than 105 are typically obtained.

Summary of the Invention

The use of repeated embossing patterns on wet-laid cellulosic fibrous structures is disclosed to improve the cleanability of cellulosic fibrous structures. The embossing pattern is discontinuous in one or more diagonal directions and includes discontinuous embossed portions of different distances. The detergency of the cellulosic fibrous structure can be measured and denoted as one index (index is 105 or greater, preferably 110). Exponents are represented by equations. In a preferred embodiment of the invention, the embossed pattern is in angular form. In a more preferred aspect of the invention, the embossed pattern is in the form of a lozenge. Typically, the cellulosic fibrous structure comprises two or more layers. Each layer comprises discontinuous embossed regions and essentially continuous unembossed regions, each of the discontinuous embossed regions of one layer being oriented into the unembossed region of the opposite layer.

The present invention relates to the use of embossing patterns on wet-laminated cellulosic fibrous structures for excellent cleaning reactions. The present invention relates to cellulosic fibrous structures that can be used in human cleansing areas, such as dry toilet tissues, paper towels, cosmetic tissues, cosmetic and therapeutic skin care products and dry wipes, and other surfaces such as kitchens and It applies in particular for cellulosic fibrous structures which can be used to clean bathroom surfaces and to clean surfaces in need of cleaning, such as machine or vehicle surfaces. Briefly, the following will focus on cellulosic fibrous structures, such as paper towels and toilet tissues, for application to human skin, but should be understood in view of the foregoing description of the broader applicability of the present invention.

It is believed that the present invention will be better understood from the description with reference to the accompanying drawings, in which:

1 is a partial vertical cross-sectional view of a wet-laminated cellulosic fibrous structure according to the present invention;

2 is a plan view of a more preferred embossing pattern on the wet-laminated cellulosic fibrous structure.

As used herein, the term “embossing” refers to fiber-fiber bonding by vertically deflecting a relatively small portion thereof relative to the plane of the cellulosic fibrous structure and impinging the projected portion of the cellulosic fibrous structure against a relatively hard surface. Refers to the process of permanently cleaving. Typically, embossing results in permanently deformed deformation of the deflected "embossed site". The embossed portion protrudes toward the opposite layer, at right angles to the plane of the cellulosic fibrous structure. As used herein, the term "discontinuous" means not adjacent.

Cellulosic fiber structure

The cellulosic fibrous structure 10 according to the invention is not necessarily flat but is macroscopic two-dimensional plane. The cellulosic fibrous structure 10 has some thickness in the third dimension. However, the third dimension is relatively small compared to the actual two dimensions, or the ability to manufacture the cellulosic fibrous structure 10 having a relatively large measure in the first two dimensions. 1 shows a partial vertical cross-sectional view of a cellulosic fibrous structure 10 according to the present invention. The cellulosic fibrous structure 10 of the present invention comprises at least two layers, ie layers 11 and 12. Each of layers 11 and 12 has two discrete bands, ie generally essentially continuous unembossed region 13, and discontinuous embossed portions 14 projecting outwardly, preferably perpendicularly therefrom. It includes. Each of the discontinuous embossed portions 14 of one layer 11 and 12 is oriented towards the non-embossed region 13 of the opposite layers 11 and 12. The non-embossed region 13, and the embossed portion 14 of each layer 11 and 12, consist of fibers close to the linear element.

This fiber is a constituent of the cellulosic fibrous structure 10, which has one dimension along the longitudinal axis of the fiber being two relatively small other dimensions (perpendicular to each other, radial and perpendicular to the longitudinal axis of the fiber). It is relatively large because it is relatively large. Microscopic examination of the fiber may reveal two different dimensions compared to the major dimension of the fiber, but these other two smaller dimensions need not be substantially the same or constant throughout the axial length of the fiber. It is important, however, that the fiber can be bent about its axis, can bind to other fibers, and can be dispensed by a liquid carrier or air. Fibers comprising the cellulosic fibrous structure 10 can be synthesized (eg, polyolefins or polyesters); Preferably cellulosic (eg, cotton linter, rayon or bagase); More preferably wood pulp, such as soft wood (bark or conifer) or hard wood (pizza or deciduous). Herein, the fiber structure 10 is considered to be "cellulosic" when it comprises at least about 50% by weight or at least about 50% by volume of cellulosic fibers not limited to the fibers listed above. Cellulose mixtures of the wood pulp fibers comprising soft wood fibers having a length of 2.0 to about 4.5 mm and a diameter of about 25 μm to 50 μm and hard wood having a length of less than about 1.0 mm and a diameter of about 12 μm to 25 μm are described herein. It has been found to be suitable for work for sex fiber structures. If wood pulp fibers are selected for the cellulosic fibrous structure 10, the fibers may include chemical processes (eg, sulfite, pearlate and soda processes) and mechanical processes (eg, stone groundwood processes). It can be prepared by any pulp process. Alternatively, the fibers can be produced or recycled by a combination of chemical and mechanical processes. The type, combination and process of fibers used is not critical to the present invention. Hard wood and soft wood fibers may be layered throughout the thickness of the cellulosic fibrous structure 10.

Wet-Laminated Cellulose Fiber Structures

According to the invention, the cellulosic fibrous structure 10 is wet-laminated using a machine associated therewith according to the theory associated with papermaking. In the wet-lamination process, the fibers are mixed with chemicals and then mixed with water to obtain a single dispersion called so-called slurry at a very high dilution of 0.01 to 0.5% by weight of fibers. The slurry is then deposited on a mobile wire screen that drains excess water and randomly places the fibers within a single web, and then binds and finishes as needed. Webs are typically formed at speeds of up to 300 meters per minute from textile fibers and 2500 meters per minute for tissue made from pulp fibers.

Embossing pattern

As in FIG. 1, the embossed portions 14 of the layer 11 do not overlap with the embossed portions 14 of the layer 12. The embossed portions 14 of each layer 11 and 12 show relatively high density discontinuous areas due to the denseness of the fibers occurring during the embossing process. The essentially continuous non-embossed region 13 has less density than the embossed region 14, but the essentially continuous non-embossed region 13 is not dense in the embossing process. In essence, the density of the continuous non-embossed region 13 is close to the density of the discontinuous embossed portions 14 before the embossing process begins.

According to the present invention, using a repetitive embossing pattern on the wet-laid cellulosic fibrous structure 10 to improve the cleaning performance of the cellulosic fibrous structure 10, the embossing pattern is discontinuous in one or more diagonal directions. And discontinuous embossing portions 14 of different distances. "Discontinuous" means that there is an interruption in equidistant intervals of the embossed portion 14 on the layers 11 and 12. As used herein, the term "repetitive" means that the pattern is formed one or more times in the cellulosic fibrous structure 10. The embossed portion 14 of the cellulosic fibrous structure 10 depends on the type of device used to make the cellulosic fibrous structure 10. A preferred aspect of the present invention is that the embossed pattern has a angular form. In a more preferred embodiment of the invention the embossed pattern is in the form of a lozenge. More preferred embodiments are illustrated in FIG. 2. However, any shape is possible, and these shapes include polygons, semicircles, ellipses, and the like, which include but are not limited to any combination of shapes that provide discontinuous repetitive diagonal patterns.

Detergent Index

As mentioned above, a repetitive embossing pattern is used thereon to improve the cleanability of the cellulosic fibrous structure 10. The detergency is expressed by the index CPI _E , which is 105 or more, preferably 110. Table 1 shows the results from the test in which the cleaning performance of DNE (sample with preferred embossing pattern) and normal sample (sample with embossing but no pattern) is measured. Suitable methods for calculating the cleanability index of the cellulosic fibrous structure 10 of the present invention are described in the section "Description of Test Procedures" below.

In all the samples tested, the basis weight was 46.8 g per 1 m ² , the cleaning pressure applied was 800 g (by weight) and 4 sheets with the cleaning action applied. These specific values have been chosen for testing, but other values may equally apply. Twelve measurements were obtained and their average values are prepared in Table 1 above. Cleanability is a function of the amount of contaminant removed divided by the number of sheets used for cleaning. For experimental purposes, a value of 0.8 g is chosen to represent the maximum removable amount of contaminants. Thus, at the ideal cleaning ability, the amount of contaminants removed is 0.8 g and the sheet used by the consumer is one, so that the cleaning capacity has a value of 0.8. Using DNE and the calculated cleanliness values (CPV _E and CPV _R ) of the normal sample, the cleanliness index (CPI _E ) can be calculated. The cleansing power index (CPI _E ) is represented by the following equation:

Where

CPI _E is the cleaning power index of the fiber structure 10;

CPV _E is the cleaning capacity value of the fiber structure 10;

CPV _R is the washability value of the fiber structure 10 without the embossing pattern;

CPV _E is the number of contaminants / sheet of the fiber structure 10 removed from the fiber structure 10;

CPV _R is the number of contaminants removed from the fiber structure 10 without the pattern / the sheet of fiber structure 10 without the pattern.

In the above CPI _E equation, the value 100 is assumed to be the washability index of a normal sample type. From the results shown in Table 1 it can be very clearly seen that the CPI _E 's washability index for the DNE samples is much greater than 100 (ie 105 or more, preferably 110). This suggests that the consumer has a very positive response due to the presence of certain embossing patterns on the cellulosic fibrous structure 10.

Description of the test procedure

Described herein is a method for schematically describing a procedure for calculating the cleanability index of the cellulosic fibrous structure 10 of the present invention. The cellulosic fiber structure 10 to be used as a sheet of toilet tissue is selected.

Mechanical cleaning method

1.1 materials

1.1.1 DC-fix foil (Product No. 346-0012 from Konrad Hornbush AG, 64679 Weissbak, Germany);

1.1.2 light gray plates used as pads for DC-fixed foils;

1.1.3 artificial fecal material (Feclone BFPS 6, 1.3% initial solution);

1.1.4 glass jars with lid (dimensions 75 mm × 75 mm);

1.1.5 slide (dimension of wood block: 80 mm × 80 mm);

1.1.6 speed regulating equipment (motors);

1.1.7 Weighing Scales

1.2 Procedure

1.2.1 Prepare artificial fecal material according to the manufacturer's instructions. (It is important to note that the mass should be cooled at room temperature without mechanical assistance (eg mixer)).

1.2.2 Adjust the weight of the slide to the appropriate weight for the toilet tissue.

1.2.3 Weigh the four sheets of toilet tissue and fill in the table.

1.2.4 Place four sheets in a pile at the base of the slide and connect them to the speed control equipment.

1.2.5 Place the prepared slide horizontally on its face.

1.2.6 Place the slide on a weighing balance and add 0.8 g of artificial fecal material. The mass is swept away from the slurry directly into the indicated box on the DC-fixed foil.

1.2.7 Glass jars are applied to the mass, and circular motions (five times) are performed to disperse the mass to about 30-40 mm in diameter. The procedure is carried out without additional pressure on the glass.

1.2.8 Insert a 1000g weight directly into the center of the glass jar and close with a lid. After 5 seconds, the glass jar is pushed over the mass with the weight without applying additional pressure. Place two fingers on the back of the glass jar and use these fingers to push the glass jar towards you (distribute it within 5 seconds).

1.2.9 Remove the weight and glass jar.

1.2.10 The dispersed mass is pushed back into the box marked on the DC-fixed foil using the sharp edge of the glass jar. Push from base to top

1.2.11 Take a glass jar and apply it to the mass. The glass jar is placed just above the edge of the DC-fixed foil without applying any additional pressure on it.

1.2.12 Leave the slide for 5 seconds.

1.2.13 Turn on the speed control and pull the glass jar over the mass using 7.8 cm per second.

1.2.14 After scrubbing 10 cm away, stop the machine.

1.2.15 Leave the slide for 5 seconds.

1.2.16 Weigh toilet paper and fill in the table.

Precautions:

Clean the DC-fixed foil after each measurement.

The artificial fecal material is mixed before placing on the slide.

Glossary of Terms

10 Cellulose Fiber Structure

11, 12 layers

13 non-embossed areas

14 embossed areas

Claims (6)

Detergency to improve the detergency of the cellulosic fibrous structure 10 of a repetitive embossing pattern comprising discontinuous embossed portions 14 of discontinuous and different distances in one or more diagonal directions (indicated by Equation 1 below) Use on wet-laminated cellulosic fibrous structure 10 such that the index (CPI _E ) is 105 or greater): Equation 1 Where CPI _E is the cleaning power index of the fiber structure 10; CPV _E is the cleaning capacity value of the fiber structure 10; CPV _R is the washability value of the fiber structure 10 without the embossing pattern; CPV _E is the number of contaminants / sheet of the fiber structure 10 removed from the fiber structure 10; CPV _R is the number of contaminants removed from the fiber structure 10 without the pattern / the sheet of fiber structure 10 without the pattern. The method of claim 1, Use of an embossing pattern with a cleansing power index (CPI _E ) of preferably 110. The method according to claim 1 or 2, Use of angular embossing patterns. The method of claim 3, wherein Use of an embossed pattern in the form of a lozenge. The method according to any one of claims 1 to 4, Use of an embossed pattern in which the cellulosic fibrous structure (10) comprises at least two layers (11 and 12). The method according to any one of claims 1 to 5, Each layer 11 and 12 includes a discontinuous embossed portion 14 and an essentially continuous non-embossed region 13, each of the discontinuous embossed portions 14 of the one layer 11. Use of an embossed pattern oriented towards the non-embossed region 13 of this opposite layer 12.