FI71797C - FOERFARANDE FOER FOERBAETTRANDE AV KRAEPPAPPERSPRODUKTERS ABSORPTIONSEGENSKAPER GENOM SAETTANDE TILL PAPPERSBANAN AV SMAO MAENGDER YTAKTIVA VAET- OCH MJUKNINGSMEDEL. - Google Patents

Description

1 71797

The invention relates to a method for improving the absorption properties (absorption rate, absorption capacity) of crepe paper products such as toilet, kitchen towel and hand towel papers. The improvement of the absorbency takes place as a kind of processing step, in which 10 small amounts of surfactant wetting and softening agents are added to the paper web, which have the effect of improving the absorbent properties of the paper. Spraying or printing techniques or roller methods are used as the method of addition.

The absorbent chemicals (wetting and softening agents) on the market are known to improve the absorbent properties of crepe paper. Conventional attempts have been made to use them by adding them to the wet end of the paper machine, i.e. to the fiber stream entering the paper machine.

However, their use as a wet topping for a paper machine has certain negative effects on machine production, paper quality, and manufacturing economy; of them in the next.

One of the most interfering factors in crepe machine production and productivity when using a wetting and softening agent is the loss or "disturbance" of the adhesive layer between the Yankee cylinder and the paper web. A suitable training layer is essential for successful creping. This formation layer must not be too weak or too strong to obtain the desired degree of creping-30 for the crepe paper and the production of the paper machine is not disturbed. Too weak an adhesive layer results in frequent replacements of crepe scrapers and premature wear on the Yankee cylinder surface.

The use of wetting and softening agents at the wet end of the paper machine 35 also generally impairs the dry and wet strengths of the paper. Crepe papers are required to have certain strength properties in accordance with the runnability, processability and usability requirements of the paper. Dry strength is an important 2 71797 property on all crepe products and very important especially on toilet and kitchen towels. Wet cheese is most important mainly on kitchen towels, hand towels and face towels.

By adding the chemicals that improve the absorbent properties of the paper to the paper web according to the present invention, the above-mentioned negative features associated with conventional wet-topping can be eliminated. The amount of chemicals to be added in the process according to the invention is preferably 0.05 to 0.2% by weight of the paper. The chemicals are added to the paper in an organic or inorganic medium, e.g. as a 10-20% aqueous solution.

Absorbents can be surfactants (surfactants), such as wetting and softening agents, which are often polyether alcohol polyethylene oxide, sulfate, sulfonate or succinate-based surfactants or surfactant mixtures.

By selecting a suitable chemical, the absorbency of the fresh paper is improved and at the same time the chemical slows down the aging of the paper. Preferred chemicals in this way are, for example, cationic ethylene oxide derivatives of alkylarylamide and anionic phosphate esters.

The addition of very small amounts of chemicals to the surface of the paper is carried out by spraying or roller methods or by printing, e.g. flexographic printing. Spraying can be performed either airless or airy. Airless spraying is performed by liquid pressure alone and can be low or high pressure spraying. Because air is used in air spraying, the amount of diffuse spray is higher than in air-free spraying. When evaluating an air-free and air-free compression method in terms of usability, environmental hygiene (diffuse fog) and investment costs, airless low-pressure spraying could often be considered the best option.

In the following embodiments, different amounts of surfactants were added to different grades of paper (finished, dry paper web) by pressing or spraying as a 10-20% aqueous solution.

3,71797 To determine its absorbent properties, the paper thus treated was subjected to a water droplet test to determine the time taken for 1 ml of water to be absorbed into the paper. The effect of chemicals on paper aging was investigated by an immersion test if 2.5 g of aged paper (aged for 15 minutes at 130 ° C) was pressed into a ball and the time required for the paper ball to completely wet with water was determined. In addition, to investigate the strength properties of the paper, the tensile index of the paper was determined according to the standard SCAN P16: 76 and the wet strength of the paper according to the standard SCAN P20: 67 in the machine direction (KS) and cross direction (PS). Paper to which no surfactant had been added was used as a reference.

Example 1 2

To the bleached hand towel web (43 g / m 2) was added 15 flexographic printing techniques using Berocell 564 surfactant solution (cationic ethylene oxide derivative of alkylarylamine, manufactured by Berol Kemi AB). The surfactant solution was made up in water and contained 20% of active ingredient. The pulp composition of the paper was: bleached sulfite 100%.

2 20 Bleached hand towel, 43 g / m, Berocell 564

Surfactant% Water drop test Immersion test (s) aged (paper) (s) _ _ (15 min, 130 ° C) _ 0 (untreated) 15.4 17.5 0.08 6.0 5.5 25 0.14 5 .1 5.2 0.18 4.3 6.1 0.22 4.8 5.3 0.26 3.9 3.2 0.34 4.1 3.7 30 4 71 797

Surfactant% Tensile index (Nm / q) Wet strength (%) (paper) KS_PS_ KS_PS_ 0 (untreated) 13.0 13.0 20.7 19.5 0.08 11.7 13.8 22.1 17.9 5 0.14 12.4 12.6 19.7 17.9 0.18 11.8 12.3 20.2 17.9 0.22 12.3 13.5 21.3 17.1 0.26 12, 2 12.3 19.4 17.5 0.34 12.0 12.1 20.1 18.7 10

Example 2 2

Airless low pressure spray was added to the yellow hand towel web (43 g / m 2) using Berocell 564 surfactant solution. The surfactant solution was made up in water and contained 10% of active ingredient. The pulp composition of the paper was: bleached sulphite 20%, recycled pulp 80%.

2

Yellow hand towel, 43 g / m, Berocell 564

Surfactant% Water droplet test Immersion test (s) (aging

(from paper) _ (sj_ (nett 15 min, 1 30 ° C

20 0 (unprocessed) 13.3 15.1 0.12 7.8 9.7 0.15 7.9 8.6 0.20 6.9 7.8

Surfactant% Tensile index (Nm / g) Wet strength (%)

25 (from paper) KS_PS_ KS_PS

0 (raw) 8.8 7.6 18.7 17.6 0.12 8.9 6.9 19.3 18.0 0.15 8.4 7.3 19.9 18.3 0.20 8 , 7 6.6 19.2 18.2 30

Example 3

Progasol 104 surfactant solution (anionic phosphate ester, manufactured by Millmaster - Onyx Inter-35 national) was added to the bleached hand towel web using the flexographic printing technique. The surfactant solution was made up in water and contained 10% of the active ingredient. The pulp composition of the paper was: bleached sulfite 100%.

2

Bleached hand towel, 43 g / m, Progasol 104

Surfactant% Water drop test Immersion test (s) (aged 5 (from paper) _ (s) _ (nett 15 min / 130 C) 0 (untreated) 15.7 12.2 0.15 5.0 6.5 0.17 5.0 5.9 0.26 4.7 3.4 10 Surfactant% Tensile index (Nm / g) Wet strength (%)

(from paper) KS_PS_ KS_PS

0 (unprocessed) 12.4 13.1 21.0 19.5 0.15 12.4 13.1 19.8 16.7 0.17 13.2 12.5 19.4 18.0 15 0.26 12.3 12.7 20.0 17.5

Example 4 2

An airless low pressure spray was added to the household towel web (22 g / m 2) using Berocell 564 surfactant solution.

The surfactant solution was made up in water and contained 10% of active ingredient. The pulp composition of the paper was: bleached sulphite 60%, chemimechanical pulp 40%.

2

Household towel, 22 g / m, Berocell 564

Surfactant% Water drop test Immersion test (s) (aging (from paper) (s) 1 ml (15 min, 130 ° C) 0 (untreated) 14.3 40.4 0.20 1.9 4.5 0, 28 2.0 4.5 0.35 1.9 4.2 30 Surfactant% Tensile index (Nm / g) Wet strength (paper) KS_PS KS_PS_ 0 (untreated) 8.6 20.2 19.5 0.20 8, 3 20.0 19.5 0.28 8.7 19.8 19.2 35 0.35 8.4 20.2 19.7 6 71797

The results show that the absorbency of fresh paper (water-drip test) with the addition of surfactant is significantly improved compared to untreated paper. The results obtained from the immersion test on aged paper show that the paper treated with tensi-5s retains its sinking properties (wets well with water and thus decomposes more rapidly in water). Untreated aged paper, on the other hand, has poor sinking properties. No significant deterioration in tensile index and wet strength values of surfactant-treated paper was observed compared to untreated paper.

The amount of surfactant to be added is not essential within the given limits. The composition of the pulp or the additives added to the paper, e.g. dyes, also had no significant effect on the results.

Il

Claims (8)

A method for improving the absorbent properties of crepe paper products, characterized in that surfactant wetting and softening agents are added to the paper web in small amounts in an organic or inorganic medium, preferably 0.05 to 0.2% by weight of the paper. A method according to claim 1, characterized in that the surfactant wetting and plasticizing agents are added to the paper web by killing. Method according to Claim 2, characterized in that the spraying is carried out using air-free low-pressure spraying. Method according to Claim 1, characterized in that the wetting and softening agents are added to the paper web by pressing. Method according to Claim 4, characterized in that the printing is carried out using a flexographic printing technique. A method according to claim 1, characterized in that the surfactant wetting and softening agents are added to the paper web by roller methods. Process according to Claims 1 to 6, characterized in that a cationic ethylene oxide derivative of an alkylarylamide is used as the surfactant wetting and plasticizing agent. 7 71797 Process according to Claims 1 to 6, characterized in that an anionic phosphate ester is used as the surfactant wetting and plasticizing agent.