CN1240904C - Lotioned and embossed tissuepaper - Google Patents

Abstract

The present invention relates to a paper tissue, and in particular to facial tissue, and disposable handkerchiefs. Claimed and described is a method for making a tissue paper product from a tissue paper web, the method comprising the steps of: - Passing said tissue paper web through an embossing nip formed between a first and a second embossing roll, wherein at least one of said embossing rolls comprises at least 30 embossing elements per squarecentimetre. - Applying a transferable lotion to at least portions of said tissue paper webFurther claimed are paper tissue products made in accordance with the above method.

Description

Lotion embossed tissue paper

field of invention

The present invention relates to tissue products, especially facial tissues and disposable handkerchiefs. More particularly, the present invention relates to a lotion tissue product utilizing improved quality tissue paper.

Background of the invention

Webs of paper or paper, sometimes called tubes or sheets, tissues, and products made thereof (such as paper towels, sometimes called facial tissues), are used in many ways in modern society. Facial tissue, toilet tissue, and napkin are trade terms that are collectively referred to herein as tissue products. It has long been recognized that important physical attributes for these products include strength, thickness, softness, smoothness, absorbency and lint resistance. The current research and development direction is to improve one property or improve two or three properties at the same time without seriously affecting other properties.

Softness and smoothness relate to the tactile sensation a user feels when they hold a product in their hands, rub the product against their skin, or crumple the product in their hands. Haptics is a combination of several physical properties. It can be obtained by the parameter of interest - the Physiological Surface Smoothness (PSS) parameter (eg from US Patent 5,855,738). The thickness of tissue paper products is very important to the user's touch.

Strength refers to the ability of a product to maintain physical integrity and resist tearing, tearing and shredding under conditions of use.

Absorbency refers to the ability of a product to absorb large quantities of liquids, especially aqueous solutions or dispersions. Overall absorbency as perceived by the user is generally considered to be the total amount of liquid absorbed and the rate at which liquid is absorbed when a given mass of tissue is saturated.

Hair removal resistance refers to the ability of a fibrous product and its constituent webs to bond under conditions of use, including when wet. In other words, the higher the lint resistance, the less likely the cellulose paper is to lint.

Products with high wet burst strength and typically relatively thick are produced using the air-dried method. However, traditional paper machines do not have air drying equipment, and providing such equipment represents a considerable financial investment. On the other hand, ventilated drying equipment consumes more energy than conventional drying equipment. Therefore, it is still attractive to use conventional paper machines to provide high-quality paper.

The following prior art represents the improvement of at least some of the above-discussed paper properties by processing procedures known in the art, which are particularly useful for conventionally produced papers.

WO 98/58124 published on December 23, 1998 discloses an embossing process in which the embossing units used have a height of at least 1 mm.

EP 0 408 248 published on January 16, 1991 discloses a processing method in which an embossing process and a calendering process are carried out simultaneously.

EP 0 668 152, published 23 December 1998, discloses an embossing method using non-matching embossing embossing units.

EP 0 696 334, published March 10, 1999, discloses an embossing process that avoids volume increase.

US Patent 5,855,738 discloses a method of making glossy tissue paper including a calendering process.

It is well known in the art that facial tissues and paper towels have additives such as added lotions to obtain skin care or medical benefits.

Typical representatives of these achievements are as follows:

U.S. Patent 5 525 345, published on June 11, 1996, discloses a lotion that imparts a soft and smooth feel. This patent includes a description of some of the unwanted effects of mineral oils commonly used in the art to enhance comfort. One of the important side effects is that mineral oils are easy to penetrate, for example, may penetrate the packaging material of tissue products and stain it, so special packaging materials need to be used, such as expensive moisture-proof materials. In describing these detrimental effects, this patent discloses a lotion compound comprising up to 80% fixative.

EP 0 808 157, granted 9 June 1999, discloses a medicated tissue product in which the lotion consists of both solid and liquid components. This patent relates to methods for economical delivery of lotions using improved lotion mixtures.

The present invention attempts to reduce the ill effects of very penetrating lotions by providing a paper quality and structure which is particularly suitable for lotion tissue papers, which can still be produced in a very economical manner.

In view of the prior art and the considerations described above, there remains a need for tissue products, especially facial tissues, which:

- Combining optimum strength (i.e. wet burst strength), absorbency and anti-hair removal;

- also has the ideal touch of softness, smoothness and thickness;

- It can be produced with high cost-efficiency ratio, and is more suitable for traditional paper machine production;

-Provides skin care benefits;

- realize the economic utilization of lotion;

-Ensure that sufficient lotion is transferred to the user when needed, while avoiding premature transfer of lotion when not needed.

Summary of the invention

The present invention relates to tissue products, especially facial tissues and disposable handkerchiefs. The present invention claims and describes a method of producing a tissue product using a tissue web comprising the steps of:

- passing said tissue web through an embossing nip formed between first and second embossing rolls, wherein at least one embossing roll comprises at least 30 embossing elements per square centimeter.

-applying a transferable lotion to at least a portion of said tissue web.

Tissue paper products produced according to the method described above are also claimed.

Detailed description of the invention

Suitable papermaking process

According to the present invention, the fibrous structure is produced by wet lay-up using principles and machinery well known in the papermaking art. Suitable pulp furnishes for making tissue paper substrates preferably include papermaking fibers whose basic constituent material is cellulose fibers (commonly known as wood pulp fibers) or fibers made from cellulose (eg, rayon, viscose). The present invention contemplates the use of fibers from softwoods (gymnosperms and conifers) and hardwoods (angiosperms and deciduous trees). The specific tree species from which the fibers are extracted is not important. Wood pulp fibers can be produced from natural wood by a simple pulping process. Applicable chemical methods are: sulfite method, sulfate (including sulfate slurry) method and caustic soda method. Mechanical methods such as thermochemical or Asplund methods are also suitable. In addition, various semi-chemical and semi-mechanical methods can also be used. Both bleached and unbleached fibers can be used. It is best not to use non-cellulosic fibers such as rubber.

In accordance with the present invention, tissue paper may contain a highly preferred ingredient - wet strength chemicals. Wet strength chemicals such as water soluble permanent and temporary wet strength resins preferably comprise up to 3.0%, preferably at least 0.5%, more preferably at least 0.8%, based on dry fiber weight.

A wide variety of wet strength resins can be used with the present invention. For example, Westfelt in Cellulose Chemistry and Technology (1979) Vol. 13, pp. 813 to 825, describes a number of such materials and discusses their chemical properties.

Typically, wet strength resins are water-soluble cationic materials. That is, the resin is water soluble when added to the papermaking furnish. It is very likely (even certain) that subsequent events (such as crosslinking) will produce a water insoluble resin. Also, some resins are only soluble under certain conditions (eg, pH values outside a defined range). It is generally believed that wet strength resins undergo crosslinking or other curing reactions after they are deposited on, in, or between papermaking fibers. But as long as there is a lot of water, crosslinking or curing doesn't happen very often.

Various polyamide-epichlorohydrin resins have particular uses. These materials are low molecular weight polymers with reactive functional groups such as amino, epoxy and azetidine groups. This patent document contains extensive descriptions of methods for the manufacture of such materials, including US-A-3 700 623 issued to Keim on October 24, 1972 and US-A-3 772 issued to Keim on November 13, 1973. 076 patent.

Kymene 557H and Kymene LX polyamide-shrunk chloride resins sold under the Kymene trademark by Hercules, Inc. of Wilmington, Delaware are particularly useful in the present invention. These resins are generally described in the aforementioned patent to Keim.

Reactive polyamide-epichlorohydrin resins useful in the present invention are sold by Monsanto Corporation of St. Louis, Missouri, and are available as Santo Re 31 under the trademark Santo Res, among others. These materials are outlined in: US-A-3 855 158, issued December 17, 1974 to Petrovich; US-A-3 899 388, issued August 12, 1975 to Petrovich; December 12, 1978 Patent US-A-4 129 528 granted to Petrovich on April 3, 1979; US-A-4 147 586 patent granted to Petrovich on April 3, 1979; US-A-4 222 921 patent granted to Van Eenam on September 16, 1980.

Other water-soluble cationic resins useful in the present invention are Parez brand polyacrylamide resins sold by American Cyanamid Company of Stanford, Connecticut, such as Parez 631NC and the like. These materials are outlined in US-A-3 556 932 issued to Coscia et al. on January 19, 1971, and US-A-3 556 933 issued on January 19, 1971 to Williams et al.

Other water soluble resins useful in the present invention include acrylic emulsions and anionic styrene-butadiene rubbers. US-A 3 844 880 issued October 29, 1974 to Meisel Jr et al provides many examples of these types of resins. Other water-soluble cationic resins, such as urea-formaldehyde and melamine-formaldehyde resins, are also used in the present invention. The molecular weight of these multifunctional active polymers is as high as several thousand orders of magnitude. More common functional groups include nitrogen-containing groups such as nitrogen to which amino groups and hydroxymethyl groups and the like are attached. Although less preferred, polyethylenimine-type resins are also useful in the present invention.

For a more detailed description of the above water soluble resins and their manufacture, see TAPPI Monograph Series No. 29, "Wet Strength in paper and Paperboard", Technical Association of the Pulp and Paper Industry (Pulp and Paper Industry Technology Association) (New York; 1965).

Temporary wet strength agents such as modified starches may also optionally be used. Permanent and temporary wet strength agents can be used in combination.

The present invention may comprise dry strength chemicals, preferably at a level of 3% by weight, more preferably at least 0.1%, based on the dry weight of the fibers. A highly preferred dry strength chemical is carboxymethylcellulose. Other suitable dry strength chemicals include polyacrylamides (such as a mixture of Cypro ^™ 514 and Accoststrength ^™ 711 from American Cyanamid of Wayne, NJ); starches, such as corn starch and potato starch; polyvinyl alcohols, such as AirProducts of Allentown, PA. Airvol ^™ 540 by Inc.; Guam or locust bean gum and polyacrylate latex. Suitable starch raw materials may also include modified cationic starches, such as those produced by National Starch and Chemical Company (Bridgewater, NJ) having nitrogen-containing groups (eg, nitrogen with amino and hydroxymethyl groups attached).

Chemical softening compositions, including chemical stripping agents, are optional ingredients of the present invention. US-A-3 821 068, published on June 28, 1974, teaches that chemical release agents can be used to reduce the hardness and increase the softness of tissue webs. Suitable chemical stripping agents are disclosed in US-A-3554 862 patent published on January 12, 1971. These include quaternary ammonium salts.

A preferred chemical softening mixture comprises from about 0.01% to about 3.0% of a quaternary ammonium compound, preferably a biodegradable quaternary ammonium compound; from about 0.01% to about 3.0% of a polyol compound; preferably comprising the following groups: glycerol , sorbitol, polyglycerol having an average molecular weight of from about 150 to about 800, polyethylene oxide glycol, and polyoxypropylene having an average molecular weight of from about 200 to about 4,000. A preferred range for the weight ratio of quaternary ammonium compound to polyol is 1.0:0.1 to 0.1:1.0. It has been found that it is more effective to pre-mix the polyol with the quaternary ammonium compound, preferably at a temperature of at least 40°C, prior to addition to the papermaking furnish. Additionally or alternatively, the chemical softening composition can be applied to a fully dry tissue web by, for example, printing. Note that all percentages herein are calculated on dry fiber weight unless otherwise stated.

Examples of quaternary ammonium compounds suitable for use in the present invention include the following compounds as such (unmodified) or their monoester or diester variants: the well known dialkyldimethylammonium salts and alkyltrimethylammonium salts. Examples include the diester variant of di(hydrogenated tallow) dimethyl ammonium sulfate and the diester variant of di(hydrogenated tallow) dimethyl ammonium chloride. Without being bound by theory, it is believed that the ester moiety renders these compounds biodegradable. Witco Chemical Company Inc. of Dublin, Ohio manufactures and supplies this material under the trade name Rewoquat V3512. For detailed analysis and testing procedures, please refer to WO95/11343 published on April 27, 1995.

Examples of polyols useful in the present invention include polyethylene oxide glycols having an average molecular weight of from about 200 to about 600, of which "PEG-400" is particularly preferred.

Addition of specific chemicals among the preferred chemicals listed above will result in a very beneficial effect (i.e., softness) on the paper product. The tissue paper web used in the present invention can be any conventional chemical agent known to those skilled in the art. method manufacturing.

These papermaking methods include dewatering suitable pulp, for example, using one or more papermaking felts and/or belts. The present invention is more suitable for traditional papermaking methods. Any traditional papermaking method mentioned in the present invention does not comprise air drying process. In addition, it is also possible to choose to use a papermaking method including a through-air drying process.

Stretch embossing process

The present invention is particularly concerned with conversion processing procedures well known in the art.

An important transformation process to be performed according to the invention is the embossing process in which very fine patterns are pressed with low pressure.

A typical method of embossing a tissue web is to pass it through a nip between two embossing rolls, at least one of which includes an embossing unit. Typical embossing rolls include curved or flat surfaces. Embossing elements are projections of a certain height above the plane, measured from the direction perpendicular to the axis of the embossing roll, as the distance from the surface of the curved smooth roll to the furthest point of the projection. The embossing unit has a width which can be measured on the substantially flat side of the roll surface. As used herein, the term "width" means the diameter of a circular embossing unit measured in the plane specified above (i.e. the base plane of the embossing unit), or in said plane if the embossing unit is not circular The maximum width of .

According to the invention, the embossing unit can be of any shape, for example pyramidal or hemispherical, and its cross-section can be circular, oval or square. The embossed units may form a continuous pattern, but preferably the patterns are separated from each other.

According to the invention, the embossing unit is arranged on at least one embossing roll and forms very fine patterns. The minimum number of embossing units per square centimeter of the embossing roller is 30, preferably 50, more preferably 60, more preferably 70 and most preferably 80.

According to the invention, the embossing unit is not high, its height is preferably less than 1 mm, more preferably less than 0.8 mm, even more preferably less than 0.6 mm, still more preferably less than 0.5 mm, more preferably less than 0.4 mm, most preferably less than 0.3 mm.

The ratio of embossed area to unembossed area of stretch embossing is preferably in the range of 5% to 95%, more preferably 20% to 80%, most preferably 40% to 60%. That is, most preferably, 40% to 60% of the total surface area of the tissue web is embossed.

Any known embossing roll type and mode of operation thereof are within the scope of the present invention. In a preferred embodiment of the invention, two hard metal (e.g. steel) embossing rolls are used, wherein the first embossing roll (called the convex roll) comprises raised embossing elements and the second embossing roll (called concave rolls) include matching grooves. The grooves may be mirror images of the raised embossing elements, or may be slightly smaller than actual mirror images, ie the size or shape of the grooves (eg slopes) may be slightly different.

According to the present invention, in another highly preferred embossing process, a first embossing roll comprises hard metal raised embossing elements which provide the contact surface with the tissue web and a second embossing roll comprises A tissue web contact surface of a softer material (eg rubber, preferably a material with a Shore hardness of 40-70) where the grooves are in intimate contact with the raised embossing elements.

The size of the nip between the two embossing rolls depends on the tissue web to be processed and the embossing pattern used etc. It is also restricted by the following factors: the pressure for simultaneously rolling the first embossing roller and the second embossing roller is zero or may not be zero.

When two hard metal rolls (convex and concave) are used in this process, the embossing rolls should be operated so that there is a certain gap between the raised embossing units of the convex roll and the bottom of the grooves of the concave roll, The void width is 60% to 140% of the thickness of the unembossed tissue paper, preferably 80% to 120%.

When a hard metal roll and a rubber roll are used in combination, the two embossing rolls should exert a certain pressure on each other and squeeze together. The pressure range can be 10N to 1000N per square centimeter, preferably 20N to 200N, more preferably 50N to 100N.

Modes of operation are known to be suitable for the present invention, preferably the embossing rolls are unheated and run at the same speed, but in an alternative mode of operation at least one of the embossing rolls can be heated and run at different speeds .

An important effect of the fine pattern embossing described above is to increase the caliper, ie, the volume of the tissue web. Thus, in a highly preferred mode of the invention, a single ply tissue web or single ply tissue is passed through an embossing nip. In an optional mode, multiple layers of tissue paper can pass through the nip simultaneously. However, without being bound by theory, applicants believe that the deformed embossing described in the present invention can stretch the tissue paper, causing deformation, but does not cause substantial compaction of the tissue paper. A method of parallel embossing joining of layers of tissue paper. It is more contemplated to provide a multiply tissue product using a separate joining process, wherein the joining process preferably includes an embossing process, such as "joining embossing" described below.

Application of lotion

According to the present invention, the lotion is applied to the tissue product before and after stretch embossing, more preferably after stretch embossing. The lotion can be applied by any suitable method, such as printing and spraying. The lotion can be applied to the entire surface or a portion of the surface of the tissue web or tissue product. For multi-ply tissue paper products, the lotion can be applied to all plies or only to one or both sides of selected plies. In a preferred embodiment, the lotion is applied to both exterior surfaces of the tissue product.

It has been found that lotions improve the smoothness of tissue paper and lower its PSS parameter. In addition, the lotion has skin care benefits.

Lotions may include softening/exfoliating agents, emollients, fixatives, and mixtures thereof. Suitable softening/stripping agents include quaternary ammonium compounds, polysiloxanes, and mixtures thereof. Suitable emollients include propylene glycol, glycerol, triethylene glycol, spermaceti or other waxes, petrolatum, fatty acids, fatty alcohols, fatty alcohol ethers having from 12 to 28 carbon atoms in the fatty acid chain, mineral oil and others. Silicone oils (for example, simethicone and isopropyl palmitate), and mixtures thereof. Suitable fixatives include ozokerite, stearyl alcohol and paraffin waxes, polyhydroxy fatty acid esters, polyhydroxy fatty acid amides, and mixtures thereof.

Other optional ingredients include fragrances, antibacterial actives, antiviral actives, disinfectants, pharmaceutical actives, film formers, deodorants, sunscreens, astringents, solvents, and the like. Some examples of lotion ingredients include camphor, thymol, menthol, chamomile, aloe vera, calendula extract.

According to the present invention, a transferable lotion is used, most preferably a transferable lotion comprising the ingredients listed above, this transferability ensures excellent skin care and medicinal benefits. The skilled artisan is aware of the effect of the listed ingredients on the transferability of the lotion, and the amount of mineral oil present is of course a key parameter.

As used herein, the term "transferable lotion" refers to any lotion having a transfer rate greater than 0.25% in a static lotion transfer test on unembossed paper as described herein. The transferable lotion transfer rate is preferably greater than 0.5%, more preferably greater than 1%, 2% or 5%, according to the fixed lotion transfer test performed on unembossed paper as described in the present invention. To optimize the benefit of the lotion, the level of transferability of the lotion may be relatively high. The present invention has heretofore overcome the disadvantages associated with the extensive use of highly transferable lotions.

Data were obtained for stretched embossed and unembossed tissue products under static and dynamic conditions using the test method described below:

Unembossed product Same product stretch embossed

Before applying lotion

Static Transfer 5.14% 2.25%

Dynamic Transfer 21.83% 21.12%

Data obtained from the lotion test method described hereinafter demonstrates some of the benefits of products made in accordance with the present invention. Products stretch embossed in accordance with the present invention transfer very little lotion when in static contact with a surface, but significantly more lotion when rubbed across the surface.

Surface static contact represents the contact of the tissue product with the packaging material while the product is in the packaged state. The low lotion transfer rate avoids the use of expensive packaging materials. Surface static contact also refers to the contact of the product with the user's fingertip when the tissue product is removed from the package and is ready for use (for example, in the nose area). Generally speaking, when the benefits of a lotion are desired in the nose area of the user, it is highly undesirable that the lotion run down the fingertips as this can cause a nasty greasy feeling and even require hand washing.

Wiping the surface represents the use of a lotion-type tissue product on the target area (usually the nose area). Gentle rubbing of the nose area is a very common usage and this usage can certainly be enhanced by providing appropriate instructions for use to the user.

Stretch embossed products made in accordance with the present invention transfer significantly less wash when the surfaces are in static contact than unembossed products. However, the lotion transfer when rubbed was no worse than the unembossed tissue paper product.

According to the present invention, preferred tissue paper products will achieve a lotion transfer by rubbing of at least 1.1 times, preferably 1.5 times, more preferably 2 times, static lotion transfer measured according to the test procedure described below, 5 times or 7 times, most preferably at least 8 times.

Optional processing

The manufacture of the tissue paper product of the present invention may also include the following optional steps:

Any known calendering method can be used in the converting process, however, in accordance with the present invention, typically very high calendering pressures are used. Preferably, the calendering process should be performed after stretch embossing and before lotion application.

The calendering process of the present invention involves passing one or more layers of the tissue web through a calender nip between first and second calender rolls. Both calender rolls are typically in contact with the tissue web over a length, the length of contact in this context being measured in a direction parallel to the first calender roll. The pressure applied by the calender rolls to the tissue paper web is at least 30 N per centimeter of said contact length, with which the calender rolls will press against each other for calendering purposes. A preferred pressure range per centimeter of said length may be 50N to 300N, more preferably 60N to 250N, more preferably 70N to 200N, most preferably 120N to 150N. According to the present invention, the number of tissue fiber layers to be calendered is preferably equal to the number of layers the tissue product comprises, eg two, three or four ply tissue webs can all be calendered side by side in one operation.

With known equipment and modes of operation suitable for the present invention it is preferred that the calender rolls are unheated and of the same speed, but in an alternative mode of operation at least one roll may be heated and the speed of the calender rolls varied.

The calendering process is well known in the art to reduce the caliper of tissue paper webs and is typically chosen to ensure that the caliper of tissue paper products meets required specifications.

The calendering process is known to reduce the softness to the touch of tissue paper products since the application of pressure results in compaction of the tissue web. Thus, at least in the field of toilet paper (eg tissue), the calendering process need not be carried out at too high a pressure, typically 10 N/cm to 20 N/cm for embossed tissue paper webs.

When the present invention was conceived, it was surprisingly found that the specific claimed embossing process in combination with the calendering process can produce a thick, bulky, yet very soft paper product.

More particularly, it has been found that tissue webs subjected to the stretch embossing and calendering processes also have increased caliper compared to untreated tissue webs. (For example, when a three-ply tissue web is calendered in one operation, comparing a three-ply untreated tissue web to a three-ply embossed, calendered tissue web) The effect is very impressive. Surprisingly, it is well known that a high-pressure calendering process greatly reduces the thickness of a tissue web, as described in German patent application DE O 44 14 238.2.

It has been found that the claimed process increases the thickness of the tissue web by 10%, sometimes 30%, even as high as 40%, 60%, by comparing the untreated tissue web with the treated tissue web , 80% or 100%. The stretch embossing process alone can typically increase thickness by 50% to 200%.

The tissue paper of the present invention has first and second surfaces facing each other and having a thickness perpendicular to the first and second surfaces. This thickness also refers to thin paper thickness. According to the present invention, the thickness of the 3-ply tissue paper product preferably ranges from 0.1 mm to 1 mm, more preferably from 0.2 mm to 0.5 mm.

Furthermore, the wet burst strength of the tissue paper of the present invention is preferably greater than 50 g, more preferably greater than 100 g, more preferably 150 g to 500 g, more preferably 250 g to 400 g.

It has been found that the process as claimed in the present invention significantly reduces the dry tensile strength of the tissue without seriously affecting the wet tensile strength of the tissue. Tissue papers treated using the claimed process typically have a wet burst strength of 100 g to 300 g, with a preferred ratio of dry tensile strength to wet burst strength of 0.1 to 0.3, more preferably 0.125 to 0.25, most preferably 0.15 to 0.2 .

In another aspect, the tissue paper products of the present invention preferably have a physiological surface smoothness parameter of less than 1000 microns, more preferably from 650 microns to 50 microns, more preferably from 650 microns to 300 microns.

In a preferred embodiment of the present invention, the number of layers of the tissue paper product provided is two to four layers, most preferably three layers. For all tissue papers having a stretch embossed pattern, preferably the pattern occupies at least 50%, preferably 80%, and most preferably the entire surface area of the tissue product.

To provide a multi-ply tissue product, multiple layers of the tissue web are juxtaposed, preferably joined by joint embossing. "Connecting embossing" in the context of the present invention means an embossing by which, according to the present invention, all the layers of a multi-ply tissue paper can be embossed in one processing step. The preferred connecting embossing has no or at least no significant influence on the smoothness of the calendered layer. Thus it is preferred that the non-embossed surface of the tissue paper constitutes the majority of the total surface, and preferably on both the first and second surfaces. In the method used in the present invention, this means that the tissue has one or more areas without joint embossing, and optionally one or more areas including joint embossing, wherein; 50%, preferably at least 80%, and in some preferred embodiments up to 99% of the tissue surface area. Most commonly, the area including the joined embossing is near the edge of the tissue paper (such as along two or four edges); the area including the joined embossing can also be used for decorative purposes (such as forming a pattern or spelling out a logo or brand name) . Areas that do not include embossments are located in a continuous area intermediate and/or around areas that include connecting embossments. The preferred connecting embossing adopts the steel-to-steel, needle-oriented embossing method, with 10 to 40 embossing units per square centimeter, and the height of the embossing units is 0.01 mm to 1 mm, preferably 0.05 mm to 0.2 mm. The preferred percentage of connecting embossed areas relative to non-embossed or finely embossed areas is from 0.01% to 5% of the total surface of the tissue product. Joining embossing results in a considerable densification of the tissue product when the joining is effected. Thus, the gap between the embossing unit and its counterpart (e.g. using two needles for needle embossing) is smaller than the thickness of the tissue paper to be embossed, typically 5% to 50% of the thickness of the tissue paper , preferably 10% to 20%, which results in an embossing pressure of 10,000 to 50,000 N/cm2.

The method of the present invention may also include providing a paper converting process suitable for tissue paper products such as paper towels. These operations typically include cutting of the tissue web.

If desired, the tissue products of the present invention can be provided with functional or aesthetic indicia. Markings can be made on one or both sides of the tissue product surface. The indicia can cover all or part of the tissue product and can be in a continuous or non-continuous pattern.

Indicia can be applied to the surface of the tissue product by any method known in the art such as spraying, extrusion and preferably printing. Gravure or flexographic printing can be used. If printing is the chosen method of marking, a printing apparatus can be constructed as described in commonly assigned US Patent 5,213,037, issued May 25, 1993 to Leopardi, II. If desired, the device may have storage shelves, as disclosed in commonly assigned US Patent 5,255,603, issued October 26, 1993 to Sonneville et al. If desired, the indicia may have perforations or fan cuts, as disclosed in commonly assigned US Patent 5,802,974, issued September 8, 1998 to McNeil. The disclosures of the aforementioned patents are incorporated herein by reference.

Test Methods

Lotion transfer test

The ambient laboratory temperature for testing is 22°C+2.2°C, and the relative humidity is 50%+10%.

a) purpose

The purpose of this test is to measure the amount of wash solution transferred to a glass surface under static and/or frictional conditions.

b) List of Equipment/Materials

1.20cm x 30cm or a glass dish of known weight.

2. A metal weight with a 2 cm x 3 cm rectangular tissue product contact surface.

3. A 5mm thick hard rubber disc of the same size as the glass disc.

4. Analytical balance (0.0001 g resolution).

c) Sample preparation

Tissue paper samples of approximately 20 cm x 20 cm were used. Spray the lotion evenly on the sample, and the amount of lotion should be selected to reach 10g lotion per square meter.

d)

i) Static testing

Place the wash solution sample on a glass dish. Cover it with a hard rubber disc, and place metal weights on top of the rubber disc. The metal weight should exert a pressure of 9kPa on the paper/glass surface.

Wait 15 minutes, then carefully remove the metal weights, hard rubber disc, and paper. Now measure the weight of the rubber disk. Subtract the two weights (glass with wash solution - glass without wash solution) to obtain the weight of wash solution transferred.

ii) Dynamic test (friction test)

Remove the lotion sample and coat the metal weight paper contact surface. The metal weight should apply a pressure of 9kPa to the paper surface (the weight can be adjusted if necessary).

The metal strip/paper is placed on a glass surface of known weight and surface dimensions 100 x 30 mm.

On a 15 cm long glass surface, rub back and forth 10 times at a rate of 50 mm/sec. Then remove the metal strip with the paper attached and measure the difference in weight of the glass dish.

f) Results

Repeat the test 10 times and take the mathematical mean as the result. The average amount of lotion transferred is reported as a percentage of the amount of lotion contained in the tissue product.

The thickness measurement includes the following steps: before measuring the thickness, the tissue paper is pretreated for two hours in an environment with a temperature of 21° C. to 24° C. and a relative humidity of 48 to 52 percent. If you want to measure the thickness of tissue paper, first peel off 15 to 20 layers of paper. If measuring the thickness of facial tissue, a sample should be taken from near the center of the package. Samples were selected and then processed for an additional 15 minutes.

The thickness of the multi-ply thin paper used in the present invention refers to the thickness of the paper when subjected to a pressure load of 14.7 g/cm ² . Thickness is preferably measured using a low duty Thwing-Albert Micrometer (Model 89-11 ) manufactured by Thwing-Albert Instrument Company of Philadelphia, PA. The total thickness of multiple layers of tissue paper is divided by the number of layers to get the thickness of each layer. For single-ply tissue paper, each ply is equal to thickness. Areas with decorations, perforations, edge effects, etc. on thin paper should be avoided if possible.

Wet burst strength was measured using an electronic burst tester under the following test conditions. The burst tester is a Thwing-Albert Burst Tester Cat. No. 177 equipped with a 2000 g load cell. The Burst Tester is manufactured by Thwing-Albert Instrument Company, Philadelphia, PA 19154, USA.

Remove the eight sheets of tissue paper and place them in a stack of two. Use scissors to cut the sample so that the length of the sample is about 228mm in the processing direction and about 114mm in the vertical direction, both of which are the thickness of two finished units.

The samples were first held together with small paper clips to age for two hours, and the other end of the sample was ventilated to separate the paper layers, allowing air to circulate between the samples. Each sample was hung by clips in a forced air oven at 107°C (3°C) for 5 minutes (10 seconds). After heating, samples were removed from the oven and allowed to cool for at least three minutes before testing.

Remove the sample strip, hold the narrow transverse edge of the sample, and immerse the center of the sample in a dish filled with about 25 mm of distilled water. Allow the sample to immerse in water for four (4005) seconds. Remove the sample, hold it in your hand and wait three (3005) seconds for the water to flow out laterally. Continue testing immediately after draining. The sample is placed with the outer surface facing up in the lower ring of the sample holder so that the wetted portion of the sample completely covers the rough surface of the sample holder ring. If fine lines appear, discard the sample and repeat the test with a new sample. After properly placing the sample in the lower ring, turn on the lowering switch of the upper ring. The test sample is now securely held by the sample positioner. The burst test starts while pressing the start button. The pressure bar starts to rise. At the instant the sample is torn or ruptured, the maximum reading is reported. The pressure bar will automatically back up and return to its original position. Using another three samples, repeat the procedure above for a total of four tests, ie four replicates. Results are reported as the mean of four replicate experiments rounded to the nearest gram.

Dry tensile strength was measured as follows: In an environmental laboratory, the test was performed on one inch by five inch (approximately 2.5 cm by 12.7 cm) paper (including handsheets and other types of paper described below), Environmental The room temperature is 28°C+2.2°C and the relative humidity is 50%+10%. Use an electronic tensile tester (model 1122, manufactured by Instron Corp, Canton, MA) operating at a crosshead speed of 2.0 inches per minute (approximately 5.1 cm per minute) and a scale length of 4.0 inches (approximately 10.2 cm) . The machine direction reference means that the machine direction length of the prepared test sample should be 5 inches (about 13 cm). To measure the machine direction dry tensile strength in this way, the paper product is cut into strips of 5 inches (about 13 cm) in the machine direction. The paper product is cut into strips of 5 inches (about 13 cm) in the machine direction corresponding to the machine direction dry tensile strength. Machine direction and cross machine direction are well known terms in the papermaking art. The tensile strength in the processing direction and the processing vertical direction is determined using the above-mentioned equipment and traditional calculation methods. The strength in each direction must be tested on at least six paper strips, and then their arithmetic mean value is taken. The dry tensile strength used in the present invention is the arithmetic mean of the average machine direction tensile strength and the average machine perpendicular direction tensile strength.

For measurements of physiological surface smoothness reporting PSS parameters, selected tissue samples should avoid fine lines, tears, perforations, and severe deviations from macroscopic uniplanarity. Before the test, the sample should be placed in an environment of 22°C to 24°C and a relative humidity of 48% to 52% for at least two hours. The sample is placed on the motorized stage and held in place by magnetic forces. Either side of the sample can be selected for measurement, but all traces should be measured on the same side.

Physiological surface smoothness is measured by scanning the tissue sample in any direction using a profilometer to obtain the displacement in the Z direction as a function of distance. The Z-direction displacement is converted into a spectrum of amplitude versus frequency by a Fourier transform. The spectrum is then adjusted using a series of filters to match human tactile sensitivity. Computes the peak height sum of the filtered amplitude-frequency curve from 0 to 10 cycles per mm, resulting in the output.

Fix a tissue sample with dimensions approximately 100 mm x 100 mm on a motorized table. Any suitable bench can be used, a bench that has been found to work well is the KES-FB-4NKES-SE with Surface Tester from Kato TechCompany Limited of Koyota, Japan, or a NuStep 2C NuLogic Dual Axis in closed loop control mode CP3-22-01 DCI Micro Precision Workbench for Stepper Motor Controller. The table has a constant drive motor that runs at a speed of 1mm per second. The sample is scanned 30 mm in the forward direction, one mm wide in the lateral direction, and then reversed. Data were collected over an area centered at a scan distance of 26 mm in both forward and reverse directions. The first and last 2mm of each scan should be ignored and not used in the calculation.

The probe tip radius of the profilometer is 2.54 microns and the applied pressure is 0.20 grams. The gauge is specified for a total displacement of 3.5 mm in the Z direction. Over the scan distance of the sample, the profilometer measures the Z-direction probe displacement in millimeters. Digitize the gauge controller output voltage at a rate of at least 20 points per second. Over the full 26 mm scan range, 512 time-surface height data points were acquired in both forward and reverse scan directions. The profilometer is fixed on the sample table so that the surface topography can be measured. The EMD 4320 WI Vertical Displacement Transducer is a suitable profilometer with an EPT 010409 probe tip and an EAS 2351 analog amplifier. The device can be purchased from Federal Products in Providence, Rhode Island.

Import digitized data pairs into standard stochastic analysis packages for further analysis. A suitable software analysis package is SAS, Cary, NC, preferably LabVIEW Instrument Control Software 3.1, National Instruments, Austin, TX. When using LabVIEW software, using LabVIEW software's Mean.vi analysis tool will result in correlated raw data pairs of surface height and time during each scan centered on the mean. The 512 data points from 16 trajectories can be converted into 16 amplitude spectra by using the Amplitude and Phase Spectrum.vi tool. All spectra were smoothed using the method described in PROC Spectra Method of SAS software. The LabVIEW smoothing filter values used are 0.000246, 0.000485, 0.00756, 0.062997, 0.00756, 0.000485, 0.000246. The output value of this tool is considered as Amp Spectrum Mag(vrms).

The amplitude data is then adapted to human tactile sensitivity using a series of frequency filters designed from Verrillo's vibration-tactile threshold data (as a function of vibration frequency) as described in the Journal of Acoustical Society of America It was proposed in the paper "Effect Of Contactor Area On The Vibrotactile Threshold", Vol.35, 1962 (1963). The data above are reported in the time domain in cycles/second and converted to the spatial domain in cycles/mm. In the 1991 International Paper Physics Conference, TAPPI Book 1 article "Methods For The Measurement Of The Mechanical Properties Of Paper tissue" (Measurement Method Of The Mechanical Properties Of Paper Tissue) There are conversion factors and filter values in the process, the author is Ampulski et al. 19 and used the specific procedure outlined on page 22 entitled "Physiological Surface Smoothness" (Physiological Surface Smoothness). The response of the filter is set to a value of 0 (less than the minimum threshold, above the maximum response frequency), varying between 0 and 1, as described in the aforementioned Ampulski et al. paper.

By multiplying the above-mentioned amplitude with an appropriate filter value for each frequency, frequency amplitude data that has been adjusted for physiological perception can be obtained. A typical and filtered amplitude spectrum is illustrated in Figure 5 of the Ampulski et al. article mentioned. The frequency-amplitude curve for Verrillo adjustments is the sum of the points at 0 to 10 cycles per mm. This curve is considered the physiological surface smoothness. The obtained eight forward and eight backward physiological surface smoothness values were then averaged and reported in microns.

Physiological surface smoothness measurements using SAS software are described in the following references: Commonly Assigned U.S. Patents: 4,959,125, issued September 25, 1990, to Spendel; 5,059,282, issued October 22, 1991, to Ampulski et al; 5,855,738 , published Jan. 5, 1999 to Weisman et al.; 5,980,691, published Nov. 9, 1999 to Weisman et al.

Either side of the thin paper can be selected for smoothness measurement, but all scan traces need to be acquired on the same side. If each side of the tissue meets the smoothness criteria set forth in the present invention, the entire tissue sample is considered to meet this criterion. Preferably both surfaces of the tissue paper meet the above criteria. Any commonly assigned patents and patent applications in the direct patent application are hereby incorporated by reference.

Claims (8)

CLAIMS 1. A method of making a tissue product from a tissue web, said method comprising the steps of: - passing said tissue web through an embossing nip formed between first and second embossing rolls, wherein at least one of said embossing rolls comprises at least 30 embossing units per square centimeter, - applying a transferable lotion having a transfer rate greater than 0.25% to at least a portion of said tissue web. 2. The method according to claim 1, characterized in that at least one of said embossing rolls comprises at least 50 embossing units per square centimeter. 3. A method as claimed in any one of the preceding claims, characterized in that the height of the embossing units is less than 0.5 mm. 4. The method according to claim 1 or 2, characterized in that the first embossing roll has a web contacting surface comprising a rubber material and the second embossing roll has a web contacting surface comprising a hard metal. 5. The method of claim 1 or 2, wherein applying a lotion to at least a portion of the tissue web is performed after the step of passing the tissue web through an embossing nip above steps. 6. A method as claimed in claim 1 or 2, characterized in that the method further comprises the step of cutting the paper to provide tissue paper products. 7. A tissue product produced by the method of any one of the preceding claims. 8. The tissue product of claim 7, said tissue product transferring a first amount of said transferable lotion to a glass surface in static contact therewith, said tissue product transferring a second amount of of said transferable wash solution is transferred to a glass surface in dynamic contact therewith, characterized in that said second amount is at least two times greater than said first amount.