MXPA00000998A - Process for producing multi-layered tissue paper products - Google Patents

Abstract

A process for producing multi-layered tissue paper products with increased softness comprises the following process steps:production of layered webs of tissue paper, assembly of the layered webs to form a multi-layered web of product which is untreated with respect to softness, and printing of the web of product in the dry state with a softening lotion having the following minimum composition in percent by weight:a quaternary ammonium compound 3 to 30%, siloxane foam suppressor 0.1 to 3.0%, aloe vera powder 0.1 to 10%a polyhydroxy softener, in particular polyethylene glycol 0.05 to 5%remainder water.

Description

PROCESS FOR DEVELOPING MULTI-LAYER TISSUE PAPER PRODUCTS FIELD PE THE INVENTION The invention relates to a process for making multi-ply tissue paper products, in particular paper handkerchiefs, with increased softness. With the requirements still increasing with respect to the quality and comfort of tissue paper products, maximum softness is becoming increasingly important, as well as improved softness and tear resistance - depending on the application of the product. In particular, softness is important in the case of paper handkerchiefs since the human nose is particularly sensitive when it is played.

BACKGROUND OF THE INVENTION It is known from the state of the art, for example from EP 0 239 910 A1 or from WO 93/09287 Al, how to produce a soft and absorbent tissue paper by adding a chemical solution to the pulp containing cellulose fiber. softener consisting, for example, of a quaternary ammonium compound such as diethyl ester dimethyl ammonium chloride and a polyhydroxy softener such as polyethylene glycol in a 1% solution. Other qualities of the product, for P977 example wet strength, improved biological degradation capacity, etc., can also be achieved for the improvement in softness, depending on the composition of the active ingredients of this solution. However, the addition of the softening solution in the wet region of the papermaking machine has disadvantages. For example, the active ingredients are distributed over the entire volume of the weft in tissue layers, thus, a large amount of softener has to be added with respect to the amount of the paper fiber. In addition, the positively charged molecules of the quaternary ammonium compound present in the solution have to neutralize the negatively charged fibers in the cellulosic pulp. This leads to increased consumption of softening solution. Finally, an amount of only 0.4 kg remains in the product as an active ingredient with an addition of, for example, 11 kg of active softener per ton of paper pulp. The known process therefore involves a great waste due to the addition - of the softening solution "to the end of the plot" of the production process.

OBJECTS AND ADVANTAGES OF THE INVENTION Based on the aforementioned problems, the P977 object of the invention is to provide a process for making multi-ply tissue paper products with increased softness, which is accompanied by the most economical consumption of softening substances.

DETAILED DESCRIPTION OF THE INVENTION This object is achieved by means of the process steps mentioned in claim 1, mainly: production of tissue paper plies in layers. assembly of the plies in layers to form a web of multiple layers of product that is not treated with respect to the softness, and printing of the web of product in the dry state, with a softening lotion having the following minimum composition in percentage by weight : - a quaternary ammonium compound 3 to 30% - siloxane foam suppressor 0.1 to 3.0% - aloe vera powder 0.01 to 10% - a polyhydroxy softener, in particular 0.05 to 5% polyethylene glycol - the rest is water the preferred quaternary ammonium compound has the formula: O [R] a -N * - (CHa) a-0-C-Ra X "R1 P977 and mixtures thereof; wherein each substituent R is a hydroxyalkyl or C 1 Cg alkyl group, or mixtures thereof, preferably R is selected from C 1 Cg alkyl, - R 1 is 0 I (CH 2) -OCR, R 1 or a hydrocarbyl group C13-C19 or mixtures thereof, preferably R1 is selected from C16-C18 alkyl; R2 is a C ^ -C ^ hydrocarbyl group, or mixtures thereof, preferably R2 is selected from C13-C17 alkyl; and X- is a compatible anion, preferably chloride or methyl sulfate. As an example, diethyl ether dimethyl ammonium chloride is mentioned. The softening lotion is applied advantageously, by means of printing the weft of the product, virtually only in a superficial form where it imparts pleasant properties to the paper product. The softener lotion consumption can be divided in half, for example, in relation to the prior art in which 5.5 kg per ton of paper is applied. Due to the printing process, this amount is virtually without loss in the final product. Corresponding titration tests on a four-layer paper tissue have shown that, of this amount, 5.3 kg per ton of paper are on the two layers P977 while the softener content is only 0.1 kg per ton of paper in the two inner layers. The specified chemical composition of the softening lotion provides several advantages, some of which are manifested in conjunction with the printing process. For example, a range of siloxane foam suppressor contents is used which is much higher than in the state of the art. This suds suppressor is traditionally used only to suppress the foam formed in the product by the pressure during the packaging process. However, as the packaging step oppresses the product relatively lightly, small portions of the foam suppressing agent are sufficient. The proportion of siloxane is usually 0.01% by weight, which is about 1/10 of the proportion specified in the case of the invention. This high proportion of siloxane acts against the formation of foam during the printing process that oppresses the product much more than the aforementioned packaging process.

SUMMARY OF THE INVENTION It is also pointed out in this connection that, surprisingly, the softening lotion is insensitive to the shear stress and the so-called drip penetration is not P977 decreases due to the large addition of siloxane foam suppressing agent, contrary to expectations. This means that the hydrophilic and absorbency properties of the tissue paper product according to the invention remain virtually only as good as compared to untreated products. The advantages of the invention can be summarized as follows: - Reduced use of softening lotion. The softening lotion does not leave an unpleasant oily odor. The hydrophilic and absorbency properties of the tissue paper product do not decrease. The softening lotion is insensitive to the shear stress when applied through a printing process. The process uses non-expensive chemical substances. The polydimethyl siloxane, which is mentioned in the state of the art for this purpose, is a preferred foam suppressing agent. Due to the acidity setting of the softening lotion, it is necessary to use preservatives in the tissue paper product. However, for the printing process, rotogravure printing cylinders with a corrosion resistant surface (eg ceramic material) will be used. By using a calcium chloride and a soil release agent, the viscosity agent of the emulsion is regulated and a certain storage stability is maintained. The gravure printing cylinders that apply the softening lotion on the outer sides of the multilayer weft of the product are advantageously used for the printing process. The weights per unit area in the range of 0.5 to 6.0 g / m2 on each external side will be selected for the desired softness effect. The invention is described in detail hereinafter with reference to an example. The woven plies of a tissue paper are produced in a fairly conventional manner in a papermaking machine to produce a multi-layered paper tissue. No additional description is necessary. It should be noted simply that the weight per unit area of the layered frames is in the range of approximately 12 to 18 g / m2 in each case. Four of the layered wefts are assembled in the dry state to form an untreated four-layer product web, the layers are connected by means of a stamping process of the type described, for example, in EP 0 755 212 Al. Exposition of this document is included here. The dried product web is finally guided through a pair of rotogravure printing cylinders which apply a softening lotion having a weight per unit area of 1.7 g / m2 in each case, to the surface of the two outer sides of the product plot. The softening lotion has the following chemical composition: diethyl ester dimethyl ammonium chloride in the form of NN-di (tallowyl-oxy-ethyl) -NN-dimethyl ammonium chloride with 3 weight percent. a siloxane foam suppressant in the form of polydimethylsiloxane with 0.5 weight percent. aloe vera powder with 8 percent by weight. a polydroxy softener in the form of polyethylene glycol with 2 weight percent. hydrochloric acid with 0.02 percent by weight. a dirt release agent with 0.5 weight percent calcium chloride with 0.2 weight percent. The following should be noted with respect to the compounds used: Further details can be obtained about polydi ethyl siloxane as a foam suppressant and soil release agent from EP 0239 910 A2, the disclosure of which is included herein. Polyethylene glycol can be obtained as a commercial product known as "PEG 4000" prepared by BASF, Ludwigshafen, Germany. The same product is sold under the name "PEG 4050" as a 50% solution in water. If the polyhydroxy softener is used in this form, the proportions in the chemical composition of the softening lotion according to the invention should be doubled accordingly. Aloe vera powder is a highly concentrated form of aloe vera whose concentration is approximately 200 times that of the liquid obtained by the squeezing of aloe vera leaves. In addition, the aforementioned softening lotion in fact has very good bactericidal properties by itself. This is not only due to the pH value, but in view of the nature of the active itself and the polyhydroxy compound.

Claims (10)

1. REGVINDICATIONS; A process for making multi-ply tissue paper products, in particular paper handkerchiefs, with increased softness, by means of the following process steps: production of tissue paper plies in layers, assembly of the plies in layers to form a raster of multiple layers of product that is not treated with respect to softness, and - printing of the raster of product in dry state, with a softening lotion having the following minimum composition in percent by weight: - a quaternary ammonium compound 3 a: 30% - siloxane foam suppressor 0.1 to 3.0% - aloe vera powder 0.1 to 10% - a polyhydroxy softener, in particular 0.05 to 5% polyethylene glycol - the remainder is water 2.
2. Process according to claim 1, wherein the quaternary ammonium compound has the formula 0 [R] 2-N + (CH.) a-0- CR, X "R1 and mixtures thereof, wherein each R substituent is a hydroxyalkyl or C1-C6 alkyl group, or mixtures thereof, preferably R is selected from C ^ -8 alkyl, - R1 is O (CH2) 2-0-C-R2 or a C13-C19 hydrocarbyl group or mixtures thereof, preferably R1 is selected from C16-C18 alkyl; R_ is a C13-C21 hydrocarbyl group, or mixtures thereof, preferably R_ is selected from C13-C17 alkyl; and X- is a compatible anion, preferably chloride or methyl sulfate.
3. Process according to claim 1, wherein the quaternary ammonium compound is a diethyl ester dimethyl ammonium chloride.
4. Process according to claim 1, wherein the siloxane foam suppressant is a polydimethyl siloxane.
5. The process according to claim 1, wherein the softening lotion is adjusted to be acidic, in particular by the addition of 0.01 to 0.5% by weight hydrochloric acid.
6. The process according to claim 1, wherein the soil release agent is added to the softening lotion in a proportion of 0.1 to 1.0% by weight.
7. Process according to claim 1, wherein calcium chloride is added to the softening lotion in a proportion of 0.01 to 1.5% by weight.
8. 8. Process according to claim 1, wherein P977 the softening lotion is applied to the outer sides of the product web by means of rotogravure printing cylinders.
9. 9. Process according to claim 8, wherein the softening lotion is applied to each outer side with a weight per unit area of 0.5 to 6.0 g / m2.
10. 10. Lotion in particular for use in a process according to claim 1, comprising the following minimum composition, in percent by weight: - a quaternary ammonium compound 3 to 30% - siloxane foam suppressor 0.1 to 3.0% - aloe vera powder 0.1 to 10% - a polyhydroxy softener, in particular 0.05 to 5% polyethylene glycol _- - - - _ - - the rest is water P977