Classifications

• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47K—SANITARY EQUIPMENT NOT OTHERWISE PROVIDED FOR; TOILET ACCESSORIES
  • A47K10/00—Body-drying implements; Toilet paper; Holders therefor
  • A47K10/16—Paper towels; Toilet paper; Holders therefor
• • B08B1/143—
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B29/00—Layered products comprising a layer of paper or cardboard
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
  • D21H27/30—Multi-ply
  • D21H27/32—Multi-ply with materials applied between the sheets

Definitions

• the invention relates to a multi-ply wiping product consisting of tissue paper, be it kitchen towels, toilet paper, facial cleansing wipes, paper handkerchiefs, etc.
• Such a wiping product is used as a variety of tissue paper products.
• Various kinds of such products are available on the market, for example, in the form of kitchen towels, toilet paper, facial cleansing wipes, paper handkerchiefs, etc. Wipes of this kind are highly versatile in use and are suitable for a wealth of applications, from coarse wiping to wiping in highly demanding environments such as in printing and paint shops or in clean-room environments.
• tissue paper products and wipes available on the market are their limited absorbency.
• EP 0 851 950 Al describes a multi-ply tissue paper product including at least three plies, the middle ply of which consisting mainly of highly absorbing mechanical pulp incorporating no wet-strong means. This product has a relative water absorbency of but 5.2 g/g fiber material.
• US-PS-A-4, 360, 021 concerns an absorbent article and not wiping products.
• the absorbent article is made up of discrete zones of absorbent material which is enclosed between two tissue sheets.
• the problem to be solved with this subject matter is how to split a single big absorbent zone into many discrete smaller zones.
• With such an absorbent article the purpose is to be able to distribute and absorb a large amount of liquid which is deposited on a small area of the product. Thereby the absorbent article does need a high concentration of absorbent material on a quite small area.
• Such a product will be quite bulky, stiff and inflexible.
• the invention is based on the problem (object) of providing a multi-ply wiping product consisting of tissue paper having an improved liquid absorbency.
• tissue paper in which between at least two adjoining plies of tissue paper discrete liquid-absorbing zones of an absorbing material are located which has a higher liquid absorbency than the adjoining plies.
• tissue paper plies Preferably only tissue paper plies are present, between which the zones are provided.
• the size, distribution density and spacing of the absorbing zones need to be adapted to the particular application of the product. If the zones are too big and/or are arranged too dense or close one to another, the sheet product becomes too stiff and inflexible so that, for example, satisfactory wiping is no longer assured. On the other hand, if the zones are too small less liquid can be absorbed.
• Size in this context is understood to mean both the area (A) taken up by the individual absorbing zones between the plies and the height (H) of the individual zones.
• Distribution density is understood to be the number of absorbing zones per area unit of the sheet product .
• the spacing (L) of the absorbing zones from each other is measured between the nearest edges of two zones .
• An advantageous area (A) of the absorbing zones is in the range
• 0.01 cm 2 to 6 cm 2 preferably 0.01 cm 2 to 4 cm 2 and most preferred 0.05 cm 2 to 1 cm 2 .
• These zones may take various shapes, e.g. in the shape of a rectangle, a square, a circle, a triangle or a polygon. The zones may also be irregular in shape.
• the height (H) is in the range 0.01 cm to 2 cm, preferably 0.05 cm to 1 cm and most preferred 0.1 cm to 0.5 cm.
• the sheet product may also contain absorbing zones differing in size. The flexibility of the absorbing material also plays a role in the possible size of the absorbing zones. If the absorbing material is relatively flexible, for example in making use of mechanical pulp, larger zones may be employed without the web losing elasticity or flexibility. The situation is different when the zones consist of hard-compressed bentonite.
• the area of all absorbing zones amounts to max. 30%, preferably 20% and most preferred 10% of the area of the sheet product.
• the absorbing zones consist of a liquid-absorbing material which may be organic or inorganic.
• the absorbing material can, but need not have a higher relative absorption capacity (g absorbed liquid/g absorbing material) than the tissue paper and/or the non-woven fabrics . It is favourable for the absorbing material to have a relative absorption capacity, which is 20 %, preferably 50 % and most preferably 100 % higher than the relative absorption capacity of the tissue paper and/or the non- woven fabrics.
• Suitable inorganic material is an absorbent clay such as e.g. bentonite.
• Suitable organic materials are natural, cellulose fiber materials such as chemical pulp, mechanical pulp, CTMP, HTCTMP and chemi-mechanical pulp.
• DFR a substance of SCA Hygiene Products, Ostrand, Sweden is an example of a suitable absorbent cellulose fiber material having a high absorptive capacity.
• DFR is a compressed web having a basis weight in the range 30 to 2000 g/m 2 and a density of 0.2 to 1.0 g/cm 3 .
• DFR is further described in WO 94/10956.
• Superabsorbers having suitable properties may likewise be used, such as, for example, Saalsorb 88 made by Allid Colloids GmbH.
• the absorbing material may be put to use pelletized.
• the pellet may consist of agglomerated powdery or fibrous material compressed into a pellet.
• the absorbing material may also be achieved by size-reduction of larger components.
• the absorbing material may also quite naturally correspond to the shape of a pellet.
• the pellets can be adapted in size and shape to an embossing design.
• the size of said pellets corresponds to the aforementioned values for the absorbing zones.
• the flexibility of the absorbing material also plays a role in the possible size of the pellets. In case the absorbing material is relatively flexible, i.e. when it is, for example, mechanical pulp, larger pellets may be used without the web losing flexibility. The situation is different with pellets of hard-compressed bentonite.
• One advantageous area (A) of the absorbent pellet is in the range 0.01 cm 2 to 6 cm 2 , preferably 0.01 cm 2 to 4 cm 2 and most preferred 0.05 cm 2 to 1 cm 2 .
• the pellets may be of any known shape e.g. in the shape of a rectangle, a square, a circle, a triangle or a polygon. The pellets may also be irregular in shape.
• the height (H) is advantageously 0.01 cm to 2 cm, preferably 0.05 cm to 1 cm and most preferred 0.1 cm to 0.5 cm.
• the absorbing material may be powdery or fibrous .
• the absorbing material may be arranged in pockets between adjoining or superposed plies. These pockets are preferably formed by portions having ply bonding enclosing a portion having no ply bonding.
• the ply bonding may be achieved either purely mechanically by compression, e.g. by embossing or knurling, or chemimechanically by embossing and gluing or purely chemically by gluing.
• the portions of the ply bonding may either form a smooth transition or be discontinuous.
• the discontinuous ply bonding portions may consist of dotted or solid lines.
• an adhesive as used conventionally in paper processing may be employed, such as for example starch or polyvinyl alcohol (WO 97/11226) .
• polyvinyl acetate and carboxymethyl cellulose may also be put to use.
• polyethylene As the tissue adhesive, it needs to be melted (US 4,867,831) . Such hot melts may also be applied by spraying.
• the invention is compatible with all kinds of embossing.
• an embossing is used in which the protuberances of the embossing pattern may form the aforementioned pockets.
• embossing must not negatively affect the absorbing material. This is the reason why foot-to- foot, or punta punta, embossing or embossing by an embossing roll having protuberances against a hard, smooth roll is preferred.
• Nested (or DESL (DERW) ) embossing may also be used when the embossing pattern is suitable therefor.
• the absorbing material may be affixed by gluing one or both plies.
• an adhesive may be applied, for example, in a specific pattern to one ply. The absorbing material is then applied to this bonding substance before the second ply is brought together with the first ply.
• the absorbing material may be secured by a combination of direct gluing to one or both plies and enclosing the absorbing material in the pockets by the ply bond.
• Tissue paper consists in general and for example here of plant fibers, i.e. cellulose fibers.
• the tissue paper is formed on a fabric by dewatering an aqueous fiber suspension.
• the thus formed fiber web is then dried (DIN 6730, May 1996) .
• Tissue paper is a porous absorbing paper which is normally elastic due to wet or dry creping or rush-transfer of the paper web.
• all conventional kinds of multi-ply tissue papers having a basis weight in the range 8 to 60 g per ply may be used.
• the various plies may be the same or differ, for example, they may differ by the following properties: method of production, e.g. tissue dried by conventional methods or by through-air drying (TAD); basis weight; fiber composition or wet and/or dry strength.
• Fig. 1 is a schematic view of a prior-art tissue paper product
• Fig. 2 is a schematic view of a preferred embodiment of the invention.
• Fig. 3 is a schematic section view taken along the section line III-III in Fig. 2.
• FIG. 1 there is illustrated a schematic view of an embossed web of tissue paper 1 known from prior art.
• the circles 2 and 3 indicate the embossing pattern, each circle representing a protuberance thereof.
• FIG. 2 there is illustrated an embossed two-ply web 1 of two-ply tissue paper 5,6 in accordance with the invention.
• An embossing pattern is represented schematically on the web by small circles 2, 3.
• the shaded larger circles identify the location of absorbing zones 4 for absorbing liquid or water.
• the zones 4 may have a color different to the remainder of the product, but not necessarily so.
• the absorbing material in the absorbing zones is colorless or white, the absorbing material is hardly discernible from the outer side of the product.
• the absorbing material is colored, the color may be made use of for decorative purposes.
• the absorbing zones may also be characterized by the use of colored adhesive for gluing the absorbing material.
• characterizing the absorbing zones may also be achieved by a pattern printed on the web.
• the absorbing zones cover roughly 1.5% of the area of the two-ply web.
• Fig. 3 there is illustrated the web as shown in Fig. 2 as taken along the section line III-III.
• the absorbing material 7 of the absorbing zones 4 is enclosed by two tissue plies 5, 6 by means of protuberances of the individual plies which are connected with each other foot-to-foot.
• the water absorption of a normal, three-ply tissue paper was measured.
• the tissue paper concerned is a normal "Zewa Wisch und Weg” 1997 product of SCA Hygiene Products GmbH having a basis weight of 53 g/m 2 and an embossing pattern the same as that show in Fig. 1.
• Ply bonding is by foot-to-foot embossing with gluing. The results are listed in Table 1.
• a multi-ply web in accordance with the invention was produced manually by inserting pellets of bentonite into pockets 8.
• the pockets were formed between two plies of the three-ply tissue paper surrounded by protuberances (see Fig. 2) .
• the same tissue paper was used as in the comparative test.
• One side of the pockets was cut open in a paper ply sufficiently so that one pellet of bentonite per pocket could be inserted.
• the inserted bentonite pellets had an area of approx. 0.08 cm 2 , a height of 0.1 cm and covered roughly 0.8 to 0.9% of the area of the multiply tissue paper.
• the spacing between the edges of the nearest pellets was approx. 2.6 cm.
• the multi-ply web consists of 38 % by weight bentonite relative to dry paper. The water absorption is listed in Table 1.
• the pellets were produced by compressing dried bentonite made by Roth Vetriebsgesellschaft .
• the bentonite was compressed at 500 kPA into round wafers of approx. 10 mm diameter. These wafers were then pelletized to produce pellets of approx. 4 mm diameter.
• Test 2
• a multi-ply web in accordance with the invention was produced manually by applying between two plies pellets of superabsorber Salsorb 88 made by Allid Colloids GmbH in pockets 8.
• the pockets were formed between two plies of the three-ply tissue paper by being surrounded by embossed protuberances (see Fig. 2).
• the same tissue paper was used as in the comparative test.
• One side of the pockets was cut open sufficiently so that one pellet of superabsorber per pocket could be inserted.
• the superabsorber pellets were secured by a water-soluble double- sided adhesive tape produced by Nitto Tape.
• the inserted superabsorber pellets had an area of 0.2 cm 2 and a height of 0.03 cm. The spacing between the edges of the nearest pellets was approx. 2.5 cm.
• the tissue paper product consists of 9 % by weight superabsorber relative to dry paper. The water absorption is listed in Table 1. Table 1:

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• 2000
  • 2000-11-21 DE DE10057518A patent/DE10057518A1/de not_active Ceased
• 2001
  • 2001-11-16 AU AU2002216044A patent/AU2002216044A1/en not_active Abandoned
  • 2001-11-16 WO PCT/EP2001/013326 patent/WO2002042559A1/en not_active Application Discontinuation

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