TISÜ OF CONTINUOUS DRYING NOT CREATED TREATED AND SOFTBackground of the InventionRecently a process has been described (European Patent Application Number 94109734.7, Publication No. 0631014) which allows the protection of soft absorbent tissue structures without the use of traditional Yank.ee creping. The sheets produced by this non-creped continuous drying process can be characterized as being very three dimensional with high volume, high absorbent capacity and a fast absorbing rate. However, due to the high degree of surface contour, such leaves can also rub on the skin. Furthermore, even though the high absorbent capacity and the rapid absorbent rate of the sheets produced in this way may be ideal for some absorbent products, soft tissues such as facial tissue and for the toilet frequently find advantages in a more controlled and absorbing rate. even slower while maintaining a high absorbent capacity.
While it is known to provide tissues with lotions that can improve softness, the addition of such materials can decrease the thickness of the tissue sheets due to a partial folding of the crepe structure when exposed to processing and moisture pressures. Therefore, there is a first need to reduce the potential for rubbing of the skin while not losing the thickness of non-creped continuous drying tissues. Second, there is a need to better control the absorbent rate without losing the high absorbent capacity of these sheets.
Synthesis of the InventionIt has now been discovered that due to the wet elasticity of the non-creped continuous drying base sheet, the liquid treatment compositions can be extended to one or both outer surfaces of a non-creped continuous drying tissue without substantially decreasing the absorbent capacity or the perceived thickness of the product. The liquid treatment composition may be water-based or oil-based. Suitable water-based compositions include, but are not limited to, emulsions and water-dispersible compositions which may contain, for example, debonders (cationic, anionic or non-ionic surfactants), or polyhydroxy compounds such as glycerin or propylene glycol . More typically, the non-creped continuous drying base sheet will be treated with a bicomponent system comprising a debonder and a polyhydroxy compound. Both components can be added separately or mixed together before being applied to the base sheet.
More specifically, a non-creped and superior continuous drying tissue can be made by uniformly applying, on the surface (s) of the tissue, large numbers of individual deposits of the melted protective / wetting composition comprising a wax and an oil, and then resolidifying the composition to form a uniform distribution of the solid deposits on the surface (s) of the tissue. Because the composition is a solid at room temperature and solidifies rapidly after deposit, there is less tendency to penetrate and migrate into the sheet. Compared to tissues with liquid formulas, it leaves a greater percentage of the aggregate composition on the surface of the sheet where it can make contact and transfer to the user's skin to provide a benefit. In addition, a lower aggregate amount can be used to deliver the same benefit at a lower cost due to the efficient placement of the composition essentially on the surface of the sheet.
Therefore, in one aspect, the invention resides in a soft tissue product having one or more layers of non-creped continuous drying tissue, wherein a liquid composition has been added to one or both of the exterior surfaces of the product without a essential decrease (20 percent greater) in the absorbent capacity and / or in the perceived thickness of the product in relation to the product of untreated tissue.
In another aspect, the present invention resides in a non-creped continuous drying tissue product having one or more non-creped continuous drying layers, wherein one or both of the outer surfaces of the product have distributed, generally uniformly, deposits solidified from a composition comprising from about 30 to 90 percent by weight and from about 10 to about 40 percent by weight of wax, preferably also containing from about 5 to about 40 percent by weight of fatty alcohol, said composition having a melting point of from about 30 ° C to about 70 ° C, more specifically from about 40 ° C to about 60 ° C. For the purposes mentioned here "melting point" is the temperature at which Most of the melting occurs, recognizing that the melting actually occurs over a range of temperatures.
In another aspect, the invention resides in a method for making a soft tissue product comprising (a) heating a composition comprising an oil, wax and preferably a fatty alcohol, at a temperature above the melting point of the composition, making that the composition melts, said composition having a melting point of from about 30 ° C to about 70 ° C (b) uniformly applying the melted composition to one or both surfaces of the tissue tissue in spaced and separate reservoirs; and (c) resolidify the deposits of the melted composition. The resolidification of the deposits can occur almost instantaneously, without the need for external cooling means such as the cooling rollers, if the composition is heated to a temperature only slightly above or at the melting point of the composition. However, external cooling means such as the cooling rollers, either before or after the application of the melt, can be used if desired to accelerate the resolidification. Such instant resolidification tends to prevent the penetration of the composition into the tissue and to retain it on the surface of the tissue, which is advantageous. For example, the temperature of the melted composition may advantageously be above the melting point by about 10 c, or less, more specifically about 5 c or less, and even more specifically by about 2 c or less. As the temperature of the melted composition approaches the melting point, the viscosity of the melted composition generally increases, which further improves the tendency of the melted composition to be retained on the surface.
The amount of oil in the composition can be from about 30 to about 90 percent by weight, more specifically from about 40 to about 70 percent by weight, and even more specifically from about 45 to about of 60 percent by weight. Suitable oils include, but are not limited to, the following classes of oils: mineral oils or petroleum, such as mineral oil and petrolatum; animal oils, such as mink oil and lanolin oil; plant oils, such as aloe extract, sunflower oil and avocado oil; and silicone oils such as alkylmethyl and dimethicone silicones.
The amount of wax in the composition can be from about 10 to about 40 percent by weight, more specifically from about 10 to about 30 percent by weight, and even more specifically from about 15 to about 25 percent by weight. Suitable waxes include, but are not limited to the following classes: natural waxes, such as beeswax and carnauba wax; petroleum waxes, such as paraffin wax and ceresin; silicone waxes, such as methyl alkali metal siloxanes; or synthetic waxes, such as synthetic beeswaxes and synthetic sperm waxes.
The amount of fatty alcohol in the composition, if present, can be from about 5 to about 40 percent by weight, more specifically from about 10 to about 30 percent by weight, and even more specifically from from around 15 to around 25 percent by weight. Suitable fatty alcohols include alcohols having a carbon chain length of C? - C30, including cetyl alcohol, stearyl alcohol, behenyl alcohol and dodecyl alcohol.
In order to better benefit consumers, additional ingredients may be used. The classes of ingredients and their corresponding benefits include, without limitation, C1Q or higher fatty alcohols (lubricity, body, opacity); fatty esters (lubricity, modification of sensation); vitamins (topical medicinal benefits); Dimethicone (skin protection); powders (lubricity, oil absorption, skin protection); preservatives and antioxidants(product integrity); ethoxylated fatty alcohols; (wettability, wax processing aids); fragrance(consumer attraction); optical brighteners, sun lotions, alpha hydroxy acids, natural herb extracts, and the like.
The aggregate amount of total tissue of the composition can be from about 1 to about 40 percent by weight, more specifically from about 5 to about 25 percent by weight, and even more specifically from about 10 percent. to about 15 percent by weight, based on the weight of the tissue. The aggregate over a quantity will depend on the desired effect of the composition on the attributes of the product and the specific composition. A preferred method for uniformly applying the heated composition to the surface of tissue tissue is rotogravure printing, either direct or indirect (offset), because this is the most accurate printing process and offers maximum control of the distribution of composition and transfer rate. However other printing methods as well as flexographic printing can be used.
The coverage of the surface area of the composition is preferably uniform over substantially the entire surface of the tissue, but only partially covers the surface (s) of the tissue product. This is achieved by a large number of small spaced-apart deposits which, when viewed with normal view, seem to cover the entire surface, but in fact they do not. The actual surface area coverage of the deposits can be from about 30 to about 99 percent, more specifically from about 50 to about 80 percent. By providing a large number of very small deposits, the penetration of the composition can be controlled more easily to remain essentially on or near the surface of the tissue. Gravure printing is ideally suited for such an application by providing, for example, from about 10 to about 1000 deposits per linear inch of surface, or from about 100 to about 1,000,000 deposits per square inch. This encompasses several well-known etching techniques, such as mechanical engraving, etching-etching, electronic engraving and ceramic laser engraving. An example of suitable electronic engraving is about 250 deposits per linear inch of surface, or about 62,500 deposits per square inch. By providing such a large number of small deposits, the uniformity of the distribution of the deposit is very high. Also, due to the large number of small deposits applied to the tissue surface, the deposits are resolidified more quickly on the surface of the tissue where these are more effective to benefit the user. As a consequence, a relatively small amount of the composition can be used to cover a large area.
The uniformity of the distribution of the deposit and the degree of penetration of the composition into the tissue can be quantified by image analysis of the surface or surfaces of the tissue after treatment with osmium tetroxide to stain the aggregate-composition black. The uniformity of osmium stained tissues can be characterized by a percent coefficient of variation of about 15 or less, more specifically about 10 or less, and even more specifically from about 5 to 15. The degree of penetration ( or the lack of penetration) of the osmium stained composition can be characterized by a major gray level difference between the opposite sides of the tissue, GLnt; FF(hereinafter defined), of about 5 or greater, more specifically about 10 or greater, and even more specifically from about 5 to about 15.
The osmium tetroxide spotting treatment used to measure the uniformity and penetration of the composition is carried out by placing the tissues loosely in a glass bell jar having an opening diameter of about 12-16 inches and a depth of about 12 inches. Care must be taken not to stack the tissues, which may impair the proper penetration of the vapors to all tissues. The osmium tetroxide is received as a crystalline solid in the sealed glass ampule which is broken and placed in the bell jar with the tissues. The upper part is placed on the bell jar forming an air-tight seal. The tissues remain in the bell jar for around 24 to 48 hours. Osmium tetroxide has a high vapor pressure and easily sublimates a gas which penetrates the bell jar chamber. After the staining is completed, the bell jar is opened and the samples are allowed to vent 12 to 24 hours before handling in order to release any residual unreacted vapors. Note: great care must be taken when using osmium tetroxide. This is a powerful and highly toxic oxidizer. All procedures with this material must be carried out in a flue gas cover with adequate air flow.
In order to measure the percent coefficient of variation, the osmium-treated sheet is seen with an omnidirectional dark field light produced with an 8-bulb octagonal ring illuminator surrounding a 50-millimeter EL-Nikkor lens attached to an optical tube. extension of C-mount 10 mm. This is put into a uantimet 970 image analysis system (Leica, Deerfield, Illinois) by a chalnicon examiner. The field size (standard live frame) is 2.77 centimeters by 2.17 centimeters. Several fields of the tissue sample treated with osmium are placed under the lenses and are measured using a black screen background. Six (6) fields in total are measured. The white level examiner is always set to 1.00 volts. At the end, the histógram is printed outside and its standard deviation divided by its main gray level is the coefficient of variation. When multiplied by 100, this becomes the percent coefficient of variation.
In order to determine the main gray level difference, the image and optical conditions used are the same as described above for the uniformity measurement. But in this case, the pieces of the upper surface and the bottom surface of each tissue layer are tightly placed close together to form a "butt joint" without any separation between the two pieces. The sample is placed under the lenses with, for example, the lightest bottom surface part on the right side of the image frame and the darker top surface part on the left side of the image frame.
If the gray level histógram of the lighter background surface is measured first, the variable live frame is placed on just that region of the complete frame, with the white level of the examiner set to 1.00 volts for the entire field. Then the sample is rotated so that the lighter background surface is now on the left. The examiner adjusts again to 1.00 volts and this surface is again isolated by the variable live frame. These data accumulate in the same gray-level histógram. The main gray level of the background surface is re T TÍstra «The same procedure is carried out on the darker upper surface occupied by the other half of the image, again with the white level examiner set to 1.00 volts for the whole image. (This will tend to compensate for the general differences in the amount of the composition added to the tissue, while the purpose is to determine more accurately if the composition is on the upper surface of the background, which reflects the degree of penetration). Again, the main gray level of the upper surface is recorded, GLSüpERI0R-Finally, the difference between the two main gray levels, GLDIFF is calculated as a value inversely related to penetration.
GLDIFF = GLFONDO "GLSUPERIORNote that if GLDIFF is zero or negative, then full penetration has occurred. If GLDIFF is strongly positive, then most of the composition stained with osmium is seated on the upper surface of the tissue.
In some embodiments, the products of this invention can be characterized by their hydrophobicity which helps to avoid "wet transfer" to the user's hands during use. This property can be objectively measured by the sinking time, which is described in U.S. Patent No. 4,950,545 entitled "Multifunctional Facial Tissue" issued August 21, 1990 to Walter et al., Which is incorporated herein. by reference. The sinking time may be about 30 seconds or more, more specifically about 40 seconds or more, even more specifically from about 50 about 150 seconds or more. These sinking times can be dramatically increased by a factor of 3-5 times by heating the treated tissues of this invention to temperatures of from about 100 to about 150 ° F. Tissues treated with heat may exhibit sink times of about 150 or greater.
The tissue product of this invention may be of a stratum, of two strata, of three strata or more. In all cases, the composition is applied to the upper surface (s) of the product. The composition can be applied after the layers are put together or before the layers are put together. Individual layers can be layered or mixed (homogeneous). Surprisingly, it has been found that the mixed base sheets of tissue provide equivalent performance to the base sheets in layers, therefore the layers are unnecessary.
Brief Description of the DrawingsFigure 1 is a schematic process flow diagram for a method for making a non-creped tissue base sheet as would be done in preparation for off-line printing of the heated composition.
Fig. 2 is a schematic process flow diagram for a method of this invention in which the parent rolls of the non-creped continuous drying tissue are treated on one side using an off-line heated etching process.
Figure 3 is a schematic display of the heated rotogravure process in which the melted composition is applied to both sides of the tissue.
Figure 4 is a schematic display of a method of this invention in which both sides of the tissue product are printed with the melted composition using a combination of a heated, de-gravure photogravure printing and a heated direct gravure printing.
Figure 5 is a further schematic display of a method of this invention in which both sides of the tissue are printed simultaneously with the melted composition using the heated decentrated gravure printing.
Figure 6 is a further schematic display of a method of this invention in which both sides of the tissue sheet are printed consecutively with the melted composition using the heated decentrated gravure printing.
Figure 7 is a schematic diagram showing a process for making a non-creped continuous drying tissue sheet and applying the heated composition during the manufacturing process using a heated rotogravure printer in accordance with this invention.
Detailed Drawing DescriptionReferring to Figure 1, a method for carrying out this invention will be described in greater detail. Figure 1 describes a process for making non-creped continuous drying base sheets suitable for off-line application of the heated compositions. A trainer is shown of twin wire having a head box for making paper in layers 1 which injects or deposits a stream of an aqueous suspension of fibers to make paper on the forming fabric 2. The fabric is then transferred to the fabric 4 which serves to support and bringing the freshly formed moist fabric down in the process as the fabric is partially dewatered to a consistency of about 10 percent by dry weight. Further dewatering of the wet fabric can be carried out such as by vacuum suction, while the wet fabric is supported by the forming fabric.
The wet fabric is then transferred from the forming fabric to a transfer fabric 6 moving at a slower speed than that of the forming fabric in order to impart a stretch in the direction of the machine augmented to the fabric. A kiss transfer is carried out to avoid compression of the wet fabric, preferably with the help of a vacuum shoe 5. The fabric is then transferred from the transfer fabric to the continuous drying fabric 8 with the help of a roller vacuum transfer 7 or a vacuum transfer shoe. The continuous drying fabric can be moved at about the same speed or at a different speed in relation to the transfer fabric. If desired, the continuous drying fabric can run at a slower speed to further improve the stretch in the machine direction. The transfer is preferably carried out with the aid of vacuum to ensure deformation of the sheet to conform to the continuous drying fabric, thereby giving the desired volume, flexibility, stretch in the transverse direction and appearance.
The level of vacuum used for vacuum transfers can be from about 3 to about 15 inches of mercury (from 75 to about 380 millimeters of mercury), preferably about 10 inches (254 millimeters) of mercury. The vacuum shoe (negative pressure) can be supplemented or replaced by the use of positive pressure from the opposite side of the fabric to blow the fabric onto the next fabric in addition or as a replacement to suck it onto the next fabric with vacuum. Also, a vacuum roller or rollers can be used to replace the vacuum shoe (s).
While held by the continuous drying fabric, the fabric is finally dried to a consistency of about 94 percent greater by the continuous dryer 9 and then transferred to an upper carrier fabric 11.
The dried base sheet 13 is transported between the upper and lower transfer fabrics 11 and 12, respectively, to the reel 14 where it is wound on a roll 15 for subsequent printing of the heated composition and further conversion.
Figure 2 shows off-line printing, in which the printing operation is carried out independently of the tissue sheet manufacturing process. The sheet that is printed with the melted composition may be of a single layer or this may be of multiple layers. The roll 20 of tissue to be treated is shown being unwound. The tissue sheet 21 is passed to a heated engraving printing station comprising a backing roller 21 and an engraving roller 23, at which point the treatment composition is applied to a surface of the tissue. The resulting sheet is then wound on a roll 24 for further conversion operations.
During the printing operation, the melted composition to be applied to the tissue sheet was supplied by a heated supply tank 25 and pumped to the heated doctor application head 26 by a suitable dosing pump. It is necessary to maintain a constant temperature in the process. Therefore, the melted composition is continuously circulated between the supply tank and the application head while maintaining an adequate amount in the tank. The heated doctor applicator head supplies the melted composition to the engraved roller 7, the surface of which contains a plurality of small cells having a transfer volume necessary to achieve the desired touch effect. By way of example, a suitable etching roll has a line grid of 250 and a volume of 5.0 billion cubic microns (BCM) per square inch of the roll surface. The typical cell dimensions for this roller are 150 microns in length, 110 microns wide and 30 microns deep.
In operation the engraved roller is loaded onto the backing roller 6 to force the tissue or tissue sheet to contact the engraving roller. The backing roll can be of any material that fills the process requirements such as natural rubber, synthetic rubber or other compressible surfaces. The loading pressures may vary from about 5-50 pli (roller-to-roll interference) to an engraving roller / backing roll gap of 0.008"(no roll-to-roll contact).
Figure 3 is similar to that of Figure 2, but illustrates the printing of hot rotogravure printing on two sides of the sheet using two printing stations in sequence. Two-sided printing is desirable when the effect of the composition is desired on both sides and / or the tissue sheet consists of two or more layers.
Fig. 4 depicts the printing of two sides of the tissue sheet using a heated rotogravure printing method offset on one side of the sheet and a rotogravure printing method heated directly on the other side of the sheet. In this method, the engraving roll 23 and the backing roll 22 (now functioning as a decentered applicator roll) can be the same as the rolls used for the previously described methods. However, the second engraved roll 30 requires different liquid delivery characteristics and therefore is recorded slightly differently. For such rollers, for example, engraving specifications can be 250-line display, 5.0 BCM. Typical cell dimensions for such a roller may be 150 microns in length, 110 microns in width, and 30 microns in depth. Degraded engraving specifications can be 250 lines, 4.0 BCM, 140 microns long, 110 microns wide, and 26 microns deep.
Fig. 5 depicts a method of printing both sides of the sheet using the simultaneous heated, decentered rotogravure printing.
Figure 6 depicts a method of printing both sides of the sheet in succession using two heated offset de-roto printing stations. For each printing station, the addition of a backup roller 31 is necessary.
Figure 7 is similar to that of Figure 1 except that the dried base sheet 13 is transported to a heated rotogravure printing station comprising the backing roll 22 and the engraved roll 23. At which point the melted composition is applied to a surface of the leaf. The non-creped and treated continuous dried tissue sheet is then wound onto a roll 15 for subsequent conversion operations.
ExamplesExample 1In order to illustrate this invention, a non-creped continuous drying tissue was produced using the method essentially as illustrated in Figure 1. More specifically, the three layer single layer toilet tissue is made in which the outer layers comprise Cenibra denatured and dispersed eucalyptus fibers and the central layer comprises refined northern softwood kraft fibers.
Before forming, the eucalyptus fibers were pulped for 15 minutes at a 10 percent consistency and drained to a 30 percent consistency. The pulp was then fed to a Maule shaft disperser operated at 70oc with a force input of 2.6 kilowatts-days per metric ton. Subsequent to the dispersion, the softening agent (Berocell 596) was added to the pulp in the amount of 15 pounds of Berocell per metric ton of dry fiber (0.75 percent by weight).
The softwood fibers were pulped for 30 minutes at a 4 percent consistency and diluted to a 3.2 percent consistency after pulping, while the dispersed, disjointed eucalyptus fibers were diluted to a consistency of 2 percent. The weight of the general layer sheet was divided 35% / 30% / 35% between the layers of dispersed eucalyptus / soft refined wood / eucalyptus dispersed. The core layer was refined to levels required to achieve the target strength values, while the outer layers provided the smoothness and volume of surface. Parez 631NC was added to the core layer at 10-13 pounds (4.5-5.9 kilograms) per metric ton of pulp based on the core layer.
A four-layer head box was used to form the wet fabric with the supply of soft northern wood kraft refined in the two central layers of the head box to produce a single central layer for the described three-layer product. The turbulence generating inserts lowered about 75 millimeters of the slice and the layer dividers were used extending about 150 millimeters beyond the slice. Flexible lip extensions being held about 150 millimeters past the slice were also used, as shown in United States Patent No. 5,129,988 issued July 14, 1992 to Farrington, Jr. entitled "Slice. of extended flexible head box with parallel flexible lip extensions and extended internal dividers ", which is incorporated herein by reference. The net slice opening was about 23 millimeters and the water flows in all four layers of head box were comparable. The consistency of the supply fed to the headbox was around 0.09 percent by weight.
The resulting three-layer sheet was formed on a twin-wire former, forming roll with suction, with the forming fabrics (12 and 13 in Figure 1), Lindsay fabrics 2164 and Asten 866, respectively. The speed of the forming fabrics was 11.9 meters per second. The newly formed fabric was then dewatered to a consistency of about 20-27 percent using vacuum suction from below the forming fabric before transferring to the transfer fabric, which traveled at 9.1 meters per second (30% of the fast transfer). The transfer fabric was an Appleton Wire 94M. A vacuum shoe pulling around 150-380 millimeters of mercury vacuum was used to transfer the fabric to the transfer fabric.
The fabric was then transferred to a continuous drying fabric (Lindsay Wire T216-3). The continuous drying fabric was moving at a speed of about 9.1 meters per second. The fabric was carried on a continuous Honeycomb dryer operating at a temperature of about 175 ° C and dried to a final dryness of about a 94-98 percent consistency.
The resulting non-creped continuous drying sheet had the following properties: basis weight, 17.0 pounds / 2880 square feet; sensory panel above sand (hereinafter defined), 4.59; grit sensory panel below (hereinafter defined), 5.07; thickness of sensory panel (hereinafter defined), 4.62; absorbent rate (hereinafter defined), 1.9 seconds; and absorbent capacity (hereinafter defined), 10.8 grams of water per gram of fiber.
The "Arenilla" is determined by a trained sensory panel tester, who places the sample of interest on a smooth surface and passes his middle and index fingers through the sample in all four directions. A numerical value of 0-15 is assigned to the address with the most grit based on several standards for comparison. This is done for both sides of the tissue. The "Arenilla arriba" refers to the side of the sheet which was presented to the continuous dryer fabric. The "Sandwich down" refers to the side of the sheet presented out of the continuous dryer fabric. This parameter is associated with the amount of abrasive or sharp particles or fibers on the sheet surface. The upper numbers represent a higher degree of grit or abrasivity.
The "thickness" is also determined by a trained sensory panel. This is representative of the perceived thickness as experienced by an ordinary tissue user. The thickness was determined by holding the tissue with the thumb between the index fingers and the second. The sheet is then pulled out of this retention and the thickness value from 0-15 is assigned to the sample based on a comparison with several standard rates of different thicknesses. Higher numbers mean a greater perceived thickness.
The "Absorbent Capacity" was determined by cutting 20 sheets of the product to be tested in a square of4 inches by 4 inches and stapling the 4 corners together to form a 20-sheet pad. The pad was placed in a wire mesh basket with the tips stapled down and lowered into a water bath (30oc). When the pad became completely wet, it was removed and allowed to drain for 30 seconds while it was in the wire basket. The weight of the remaining water in the pad after 30 seconds is the amount absorbed. This value is divided by the weight of the pad to determine the absorbent capacity, which for the purposes given herein is expressed as grams of water absorbed per gram of fiber.
The "Absorbent Rate" was determined by the same procedure as the absorbent capacity except for the size of the pad that was 2.5 inches by 2.5 inches. The time of the pad to completely wet after being lowered into the water bath is the absorbing rate, expressed in seconds. Higher numbers mean that the rate at which water was absorbed is slower.
Example 2The non-creped continuous drying toilet tissue was made as described in Example 1, except that it was dispersed and a 50/50 mixture of southern hardwood and eucalyptus was used as a direct replacement for the eucalyptus dispersed in the layers. outside.
The resulting non-creped continuous drying sheet had the following properties: basis weight, 17.0 pounds / 2880 square feet; sensory panel grit up, 4.6; sensory panel grit down, 4.6; sensory panel thickness, 4.9; absorbent rate, 1.8 seconds; Absorbent capacity 10.8 grams of water per gram of fiber.
Example 3The non-creped continuous drying toilet tissue was made as described in Example 2, except that it was aimed at a sheet basis weight of 16.0 pounds / 2880 square feet.
The resulting non-creped continuous dried sheet had the following properties: basis weight, 16.0 pounds / 2880 square feet; sensory panel grit up, 5.6; sensory panel grit down, 5.9; sensory panel thickness.4. 8; absorbent rate, 1.4 seconds; and absorbent capacity, 11.2 grams of water per gram of fiber.
Example 4A moisturizing formula of the skin was prepared having a melting point of about 55-60 c having the following composition: Percent by weight1. Mineral oil 59.0 2. Ceresin wax (M.P. 64-67oC) 20.0 3. Cetearyl alcohol 20.0 4. Zinc oxide 1.0The formula was prepared by heating the mineral oil to a temperature of 55-60oC. Ceresin wax was added. The mixture was further heated to 60-65 ° C, with stirring until the ceresin wax melted. Cetearyl alcohol was slowly added to the mixture while stirring was maintained to avoid lumping. The temperature was maintained at around 55-60oC. and the mixing was continued until the cetearyl alcohol melted. The zinc oxide was added with continuous mixing. At this point the formula was ready to be used.
The resulting formula was applied to both surfaces of a non-creped continuous drying tissue base sheet as described in Example 1 through a rotogravure printing process heated to an aggregate aggregate 15 percent aggregate level as described. in Figure 4. Specifically, the formula was pre-melted at around 56 << ~ > C in a heated stainless steel supply tank. The press and press supply system (supply hoses, doctor application heads and engraving rollers) were preheated to around 55oC. The formula was transferred from the heated application heads to the decentrated and direct gravure rollers heated.
The gravure rollers were electronically recorded, and chromed on copper rollers supplied by Southern Graphic Systems, of Louisville, Kentucky. The direct engraving roll had a line screen of 250 cells per linear inch and a volume of 5.0 BCM per square inch of roll surface. The typical cell dimensions for this roller were 150 microns in length, 110 microns wide, and 30 microns deep. The offset engraving roller was a screen with 250 lines, 4.0 BCM, 150 microns long, 110 microns wide and 26 microns deep. The rubber backing roller / decentered applicator roller was a 72 Shore A Flex Touch 1 hardness tester supplied by Republic Roller, of Three Rivers, Michigan.
The direct engraving roller was set to a condition having a separation of about 0.003 inches from the rubber backing roller. The offset engraving roller was set to a condition having an interference of 0.375 inches between the gravure roller and the rubber backing roller. The combination of heated offset and direct heated engraving printer was run at a speed of 50 feet per minute. The composition deposits solidified essentially instantaneously after leaving the press.
When they were converted into individual toilet tissue rolls, the resulting tissue product was preferred by consumers for softness, thickness, absorbency and generally on the CHARMIN® Plus toilet tissue.
Examples 5-7In order to illustrate the ability of the compositions of this invention, in combination with a non-creped continuous drying tissue sheet, to improve surface feel and reduce skin abrasion while not negatively impacting the perception of sheet thickness , and to control (decelerate) the absorbent rate while not significantly reducing the absorbent capacity, three compositions were prepared as described in Table 1 given below and applied to different non-creped continuous drying tissue base sheets. The resulting properties of the three treated tissue base sheets were compared to the untreated base sheet. All compositions had melting points in the range of from about 55 ° C to about 60 ° C.
Table 1 Heated compositionsIngredient Composition 1 Composition 2Composition 3 Percent by weight Percent by weight Percent by weightMineral Oil 45 60 59 Ceresin wax 20 20 19 Behenyl alcohol 0 20 19 Dimethicone 2 0 0 Isopropyl palmitate 4 0 0 Acetulan 5 0 0 Aloe Vera Lipo Quinone 2 0 0 Vitamin E acetate 0 0 0 Stearilic alcohol 20 0 0 Zinc oxide (Microfino) 0 0 3 E emplo 5The ability of Composition 2 to reduce the abrasiveness (Arenilla) of a non-creped continuous drying tissue without significantly impacting the perception of thickness is demonstrated by Table 2. The non-creped continuous drying tissue was produced as described in Example 1. The melted compositions were applied through off-line two-sided rotogravure printing as described in figure 4. The sample designated "Not treated" was run through the machine off-line but with the printing process inactive to achieve a zero aggregate. The top aggregate (15.6 percent by weight) was achieved using the following machine conditions: The two-sided rotogravure process was operated with an interference of 0.375 inches between the direct gravure roller and the rubber backing roller. The off-center roller was set to a condition having an interference of 0.312 inches between the gravure roller and the back-up roller (or an off-center applicator roller). The cell volumes of the direct and decentralized gravure rolls were 6.0 and 5.0 BCM, respectively. The printing process was heated and maintained at around 60oc. The decreased aggregate (5.9 percent by weight) was achieved by changing the 0.375-inch interference between the direct gravure roll and the back-up roll to a 0.008-inch gap. All other conditions of the machine remained the same. Note that the aggregates of 5.9 and 15.6 percent by weight had an equal effect on leaf properties.
Table 2Effect of Composition 2 on the abrasiveness of the sheet and the thickness as perceived by the human sensory panelCompound Added Abrasivity Abrasivity Thickness (% by weight) top downNot treated 0. 0 2 .04 2 .28 4.15 2 5. 9 1. 67 1.68 4.30 2 15. 6 1. 6 1 .78 4.23Example 6The ability of compositions 1, 2 and 3 to effect large changes in the absorbent rate without significantly decreasing the absorbent capacity when applied to the non-creped continuous drying sheets was shown in Table 3. The dried tissue in continuous non-creped form was produced as described in Example 1. The heated formulas were applied through an off-line two-sided rotogravure printing as described in Example 5.
Table 3Effect of the compositions on the absorbent rate and the absorbent capacityAggregate composition Absorbent rate Capacity (% by weight) (seconds) absorbentBase sheet 1.8 10.8 1 16.4 13 9.4 2 15.4 190 9.8 3 14.9 103 9.8As shown, the decrease in absorbent capacity was only around 10 percent, even though the absorbing rate increased by one or two orders of magnitude.
Example 7The ability of composition 2, at different aggregate levels, to affect large changes in the absorbent rate without significantly decreasing the absorbent capacity when applied to the non-creped continuous drying sheets was shown in Table 4 below. The base tissue sheet was produced as described in Example 1. The heated formulas were applied through the off-line two-sided rotogravure printing as described in Example 5. Table 4Effect of composition 2 on the absorbent rate and absorbent capacityAggregate composition Absorbent rate Capacity (% by weight) (seconds) absorbentBase sheet 1.9 10.8 2 5.9 23.5 10.6 2 15.6 114 8.8It will be appreciated that the following examples, given for the purposes of illustration, are not to be construed as limiting the scope of the invention, which is defined by the following claims and all equivalents thereof.