MANUFACTORING PROCESS OF the PACKING PAPER AND the PAPERBOARD BY ADDITION TO ALUMINIUM the FIBROUS POLYCHLORIDE AND CATION STARCH SUSPENSION

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The invention relates to a method for manufacturing the paper and more particularly the packaging paper and cardboard.

The paper pulp consisting essentially of cellulose fibres is made into a dilute aqueous suspension which is brought into the headbox of the paper machine from which it is delivered to a filter cloth that are the paper sheet. The sheet is then dewatered and dried. The qualities and properties of the resulting tissue are especially defined by the conditions of the paper machine, the raw dough, the different additives is introduced into the suspension prior to the formation of the sheet and also the products is layer on the sheet of paper after the filter cloth.

The present invention provides products is added before the formation of the sheet.

The main quality of the package is the strength, it may also be desirable to make the paper resistant to humidity. The cellulose fibers from pulp to paper but often recycled paper or board, sometimes mixed with the raw dough.

The patent English GB 2,015 614 provides a method of manufacturing the packing paper and splines of the carton wherein there is added to the fiber suspension, before the headbox, cationic starch and a polyaluminium chlorosulphate basic aluminum, or aluminum sulphate alumir. The amount of cationic starch does not exceed 0.4% of the weight of cellulose fibers. It is known that cationic starch contributes to the mechanical strength of the paper and it would be useful to be able to place many more 0.4 % especially in the suspension and retain the starch in the formed sheet. Or the starch is very hydrophilic and on exceeding an amount of 0.5% it is no longer possible form the paper sheet on the filter cloth otherwise in considerably reducing the productivity of the paper machine. According to the present invention, it has been found a novel method for using upper quantities of starch to 0.5 % in the headbox of the paper machine.

The present invention is a method of manufacturing the packing paper and cardboard, to is added to the suspension containing the cellulose fibers before the formation of the sheet:

a) more than 0.5 part of cationic starch for 100 parts of cellulose fibers,

b) polyaluminium chloride

The suspension comprising the cellulose fibres can be raw or bleached, or a mixture of raw dough and of bleached pulp. Very Bouvent is added beverage filter used to the above mixture.

The cationic starch is a mixture of one or more products being marketed as the cationic starch. Examples of such products are those described in KIRK OTHMER , 3ème edition, page 503 Vol. 21. The amount is advantageously between 0.5 and 5 parts per 100 parts of cellulose fibers, and preferably between 0.7 and 2.

The polyaluminiumchloride designates the products usually called "chloride", "basic aluminium polychloride", "polyaluminium chlorosulphate basic aluminum" and preferably one or more following products:

1/the salt of formula:

Al (OH) Cl

m n

3n-m

(1)

wherein n is any, 3n-m is positive, m and n are positive integers; said can further contain a polyvalent anion " eroism selected from anions of sulfuric acids, phosphor! rce, polyphosphoric, silica, chromic, carboxylic and sulfonic, the molar ratio T preferably being,

Al

0,015 between and 0.4.

2/the salt of formula:

Al (OE) Cl, -. (SO.),

k 3n-m-2k 4 n m

(II)

k wherein, m and n are positive integers, > m + 2k 3n, the basicity m/3n is between 0.3 and 0.7 ' and k/n * 0.01 to 0.3. The product can be prepared according to the method described in the Patent US 3,929 666;

3/the salt of formula:

Al (OK), , Cl (SO.)

n 3η-τη-2ρ p m 4

(III)

wherein (3n-m-2p) /3n = 0.4 to 0.7; p = 0.04 to 0, 25η ; m/p ' 8 to 35 ; k, m, n and p are integers and z is at least 1. The product is described in the Patent GB 2,128 977;

4/chlorosulphate basic aluminum of formula:

OH (SO.) Al , Cl

k m 4 n

3n-m-2k

(IV)

wherein the basicity or the molar ratio ^ · · x 100 is between about 40% and about 65% and in that it has an equivalent ratio Al/equivalent Cl between 2.8 and 5, an apparent molecular weight MA measured by conventional light diffusing and 0Z apparent hydrodynamic diameters and 0K diffusion measured by quasi-elastic light of the following values:

KA = 7000-35000

0Z (HAS) = 350-2500

0W (HAS) = 200-1200

The product is described in the French Patent FR 2,584 699.

The amount of aluminum chloride expressed in A^O^ to be used is preferably less than 1 part to 100 parts of cellulose fibers and preferably between 0.02 and 0.3 parts.

Although can be adding the products a and b in any order and anywhere before the headbox of the paper machine, it is preferred to add the aluminum chloride after the cationic amicon. It is also preferred that the aluminum chloride is added closest to the headbox.

May also be added in the suspension of cellulose fibers prior to forming the sheet and products a_ ^ and b, other products such as dyes.

In another embodiment of the invention, may be added in addition to the cationic starch one or more products selected from polyacrylamide, polyethyleneimines, carboxymethylcellulose, urea-formaldehyde resins, melamine-formaldehyde resins, aminopolyamide-epichlorohydrin resins, polyamide-epichlorohydrin resins. Advantageously these products is used in addition to the cationic starch and in the same amount.

May also according to another embodiment of the invention, further deé products a and b or in addition to the products is added with the cationic starch such as polyacrylamides and other previously mentioned, adding a bonding agent to render the paper somewhat hydrophobic against moisture.

Although any sizing agent is suitable, advantageously the rosin is used or a mixture of one or more products selected from alkyl ketene dimers and their derivatives, fluorinated phosphates, carboxylic acid anhydrides containing a fatty chain, certain polyurethanes, styrene/maleic anhydride copolymers.

Are preferred alkyls cétènee dimers anhydrides and the d ' carboxylic scides. The amount to be used is a function of the desired properties of the paper or paperboard. Advantageously the amount is less than 10 parts per 100 parts of cellulose fibers and preferably between 0.1 and 2 parts.

Preferably the sizing agent is added evant the aluminum chloride.

May also be added in the suspension, prior to the formation of the sheet, conventional additives such as dyes, etc...

Another advantage of the invention, in addition to the good mechanical properties obtained, is a significant decrease of the material suspended in the water collected under the filter cloth during the formation of the sheet.

Another advantage of the invention is a higher productivity of the machine to paper and improved internal cohesion. All of these advantages will appear in the examples. The following examples illustrate the invention.

EXAMPLE 1 (not according to the invention)

Composition-headbox:

100% waste paper

The sizing agent: Alkyl ketene dimer ' 0.15 parts

-Features of operation of the paper machine to:

Useful Table flat width: 2.6 m

Weight: 190 g/m²

Nature paper: cover for corrugated board

Treatment after formation of the sheet: native starch spraying surface.

Cationic starch is added, 1.4 parts per 100 parts of fiber.

Speed machine: 163 m/min

Total Retention: 79%

Mullen burst Index: 2.75 (according to standard afnor NF Q 03053)

pH (the head box): 7.2

EXAMPLE 2 (according to the invention)

The reaction is carried out as in the example 1 but is additionally added, before the headbox, a aluminum polvchlorure proportion of 0.15 parts expressed in P^for 100 parts of cellulose fibers.

Is obtained:

EXAMPLE 3 (Conform to the invention)

The reaction is carried out as in the example 2 but adding aluminum chloride 0.16 portion as in the example 2 for 100 parts of cellulose fibers, is obtained:

Speed machine: 220 m/min

Total Retention: 85"

Mullen: 2.96

pE (the head box): 7.2