EP0880616A1

EP0880616A1 - Use of sugar beet pulp for making paper or cardboard

Info

Publication number: EP0880616A1
Application number: EP97904489A
Authority: EP
Inventors: Emile Wong; Massimo Bregola
Original assignee: Eridania Beghin Say SA
Current assignee: Eridania Beghin Say SA
Priority date: 1996-02-13
Filing date: 1997-02-05
Publication date: 1998-12-02
Anticipated expiration: 2017-02-05
Also published as: DK0880616T3; DE69702499T2; AU1728097A; EP0880616B1; DE69702499D1; ATE194671T1; CZ246698A3; HUP9901632A3; FR2744735A1; NO983695L; US6074856A; FR2744735B1; PL328303A1; HUP9901632A2; PL190453B1; CA2243294A1; WO1997030215A1; NO983695D0; CZ293999B6

Abstract

The use of fermented sugar beet pulp for making paper or cardboard is disclosed as well as a fermented sugar beet pulp composition produced according to a method which comprises the steps of (a) storing the sugar beet pulp under conditions suitable for lactic acid fermentation, particularly until the pH is less than around 5 and advantageously higher than around 3.5, to give fermented pulp, (b) diluting the fermented pulp, particularly until its dry matter content is of around 1-10 %, (c) mechanically processing the diluted fermented pulp to separate the parenchymal cells from the pulp and achieve a pulp size of less than around 1000 micrometers, and (d) optionally bleaching the fermented pulp from step (a) simultaneously with step (b), or bleaching the fermented pulp from step (c).

Description

U.i ti l i sati on of sugar beet pulps in the manufacture of paper or cardboard.

Technical area

The present invention relates to the use of fermented sugar beet pulps in the manufacture of paper or cardboard. The present invention also relates to a process for manufacturing fermented beet pulps. The present invention describes a method for processing beet pulps to obtain a product having good characteristics as a substitute ingredient in the manufacture of paper.

Invention background

Paper is a film made up of a network of individual welded fibers. In general, its manufacture goes through a wet process which involves cellulosic fibers. Paper pulp is produced from wood and the composition varies according to the qualities of paper. The sheet is formed after draining a uniform deposit on a canvas provided for this purpose. The long fibers (obtained from hardwood) allow the formation of a network in which the short fibers are deposited (obtained from softwood) and the whole contributes to the mechanical resistance of the material formed after drying. Additives and bulking agents are very often used to improve characteristics such as appearance, porosity and surface condition.

Beet pulp is a by-product of the sugar beet processing industry. The beets are grated and the sugar is extracted with water. This is followed by pressing in order to increase the dry matter content to around 25 to 30%. The main components of beet pulp are on average cellulose (27%),

Fémicellulose (29%), pectin (29%), the minor components being sugar (3%), lignin (3%) and ash (4%). These components together form the characteristic cellular structure of beet pulp. This structure consists of parenchymal cells held together and linked transversely by xylem and tubular phloem.

Few new economic valuations of beet pulps have been developed, mainly due to the rapid degradation of this material. Currently, the main use is to dry the pulps, optionally mix with molasses and sell them as livestock feed (70% of European pulp in 1992).

Due to the high energy cost of drying, several attempts have been made to develop new uses and treatments for undried beet pulp. The following transformations and uses have been studied: chemical or enzymatic hydrolysis, production of ethanol, biogas, enzyme and protein-rich livestock feed. With regard to the possibility of using beet pulps in fields other than those mentioned above, papermaking seems promising. The paper industry faces severe environmental pressure to improve performance, reduce pollution, use fewer chemicals and increase recycling. The combination of these elements is not an objective that can be achieved directly and new processes and additives are constantly being developed. Until now, the use of fresh or fermented beet pulp has not been carried out. The main reasons are the low proportion of cellulose contained in the pulps and the cellular structure which does not allow obtaining long fibers which could for example replace the fibers of wood. As a result, beet pulp is not considered to be suitable for the production of paper as a simple wood substitute.

However, the use of dried beet pulps for papermaking is known. Some authors have even described the possibility of using pressed and ultra-pressed beet pulps in the manufacture of paper (G. VACCARI et al., XX General Assembly of CITS, Munich, 26th - 30th June 1995).

Some work has been done to obtain a suitable material for papermaking from beet pulp. When used as a filler, the product from the pulps always results from an extraction process. Patent EP 0102 829 teaches a method of separating polymers from plant materials containing parenchymal cells under extreme pH conditions and at an elevated temperature for a short reaction time. The isolated cellulosic material, called PCC (Parenchymal Cell Cellulose), is cited as being useful in food and possibly paper applications. However, the process, which includes a severe chemical treatment followed by steam cracking and a separation / purification step, is complex and requires treating the effluents because of the chemicals used. Patent CS 0174 308 describes a method of manufacturing paper from arabinose extraction residues from beet pulps.

Patent EP 0139 658 discloses a method of depectinization and dehydration of raw beet pulps. The raw pulps impregnated with acidified water are subjected to an alternating succession of compression and decompression stages. Mechanical work produces a kind of retting of the pulp fibers. The fibers separate from each other, their directional arrangement disappears and the pectins are dissolved. The dried end product is suitable for papermaking. Only one industrial process using beet pulps for papermaking without any prior extraction has been described.

Patent EP 0644 293 discloses a process for grinding the dried pulps and the use of these crushed pulps as a filler for the paper. The dried pulps are crushed and micronized. The resulting product is tested and used in papermaking on an industrial scale. The characteristics of the paper obtained are comparable with those of paper produced according to the same process but without the beet pulps. In this process the pulps are dried and the final filler product is therefore not commercially competitive compared to other by-products such as sawdust or straw. Since papermaking is a wet process, it does not seem useful to dry the load which must be rewetted later. In addition, the grinding of the dried pulps destroys the xylem and the phloem which, otherwise, could contribute by their fibrous structure to the increase in the resistance of the paper. The present invention relates to the use of fermented beet pulps in the manufacture of paper. More particularly, this invention relates to a method for preparing a product derived from sugar beet pulps, which can be added to the pulp so as to decrease the need for raw materials traditionally used in the manufacture of paper.

Summary of the invention

It is an object of the invention to provide a method for treating beet pulps such that the treated pulps become both physically and economically suitable for use in the preparation of paper or cardboard. The invention describes paper or cardboard containing beet pulp. The present invention also describes a process for obtaining a preparation of fermented beet pulps comprising the following stages: the beet pulps are ensiled under conditions giving rise to lactic fermentation, - the fermented pulps are diluted, the fermented pulps diluted with moderate mechanical shearing.

Silage is carried out according to known methods with pulps preferably containing 15 to 35% of dry matter. Silage is continued until the pH is at least below about 5 and above about

3.5.

During the ensilage, there is production of lactic acid in quantity varying according to the sugars available. The concentration of lactic acid generally varies from 1 to 10% of the dry matter of beet pulp. The pulps are diluted to 1 to 10% of dry matter before moderate mechanical shearing. The shearing must be carried out in order to obtain an adequate distribution of the dimensions of the fermented pulps.

The present invention describes a paper or cardboard composition comprising from 1 to 50% and preferably from 2 to 25% (expressed as dry matter) of fermented beet pulps. The optimal amounts of fermented pulp added depend on the type of paper or cardboard that is manufactured and their desired characteristics. It is nevertheless preferable to replace wood fibers or old paper with at least 10% (dry matter) of fermented pulps. Preferably, the fermented beet pulps are obtained according to the process of the invention.

The present invention reveals that the resistance of paper and cardboard, measured by different parameters, is considerably increased by the replacement of a certain amount of the wood pulp normally used by the fermented beet pulps of the invention. In order to reduce the draining time of the composition thus obtained, it is preferable to use fermented beet pulps whose distribution of dimensions is suitable. The diameter of the fraction of fermented beet pulps used for the production of cardboard is less than 1000 micrometers and preferably between 150 and 250 micrometers. The present invention also makes it possible to reduce the draining time by the addition of flocculants.

Such flocculants can be chosen from the flocculants usually used for the treatment of waste water. The flocculants used in the present invention are preferably cationic polymers with a high molecular weight (greater than 1 million).

In addition, the present invention describes various kinds of paper and cardboard which contain the fermented beet pulps. These include white paper, recycled paper (brown) and corrugated cardboard.

Detailed description of the invention

It has now been found that, under certain conditions, the wet pulps can be stored for a longer period and that the product obtained has characteristics which make it entirely suitable for use in the production of paper and cardboard.

When beet pulps are stored for a long time under anaerobic conditions, in silos or in silage, the pulps undergo lactic fermentation. This results in a change in the pH and the composition of the material.

The present invention discloses that after fermentation under these conditions, it is easier to separate the parenchymal cells and obtain, by moderate mechanical wet shearing, a product suitable for papermaking. In this way it is possible to obtain a suspension of cut xylem and phloem and separate parenchymal cells which is suitable for direct incorporation into the final wet papermaking process.

It is an object of the present invention to provide a method of processing beet pulps such that the treated pulps become both physically and economically suitable for use in the preparation of paper or cardboard.

The invention describes a process for obtaining a composition of fermented beet pulps comprising the following steps:

- the beet pulps are ensiled under conditions giving rise to lactic fermentation,

- the fermented pulps are diluted,

- the diluted fermented pulps are subjected to moderate mechanical shearing.

In the invention, the use of a composition of fermented sugar beet pulps in the manufacture of paper or cardboard can be considered in particular as a substitution for short wood fibers.

Silage is carried out according to known methods with pulps preferably containing 15 to 35% of dry matter. Silage is continued until the pH is at least below 5. The pulps are diluted to a dry matter content of 1 to 10% before moderate mechanical shearing.

It is known that pressed beet pulps can be ensiled to preserve them from unwanted decomposition. This process is most commonly used to protect this perishable product. The other alternative is drying up to 90% dry matter. This drying has the disadvantage of being very costly in energy, whereas it is useless since the load must be rewetted during its implementation in the wet process of manufacturing paper. The fermentation process starts spontaneously under anaerobic conditions with the lactic acid bacteria present, without the need to add a ferment. These microorganisms transform the residual sucrose from pressed beet pulps into lactic acid, causing a drop in pH and thus maintaining the structure of beet pulps. It is also possible to carry out the fermentation by inoculating the beet pulps with specific strains of microorganisms capable of developing well from polymeric substances such as cellulose, pectin and hemicellulose and which degrade these polymers. The outcome of silage is linked to the microbiological state of the pulps and also depends on conditions such as the initial temperature, temperature variations in the silo, the amount of sucrose still present, the oxygen content of the air, humidity and pH. When the correct conditions are applied, the result is a softer material whose acidity is mainly due to lactic acid and whose pH is less than 5. It has been found that fermented beet pulps which have been subjected to good lactic fermentation can easily undergo mechanical treatments in order to separate their parenchymal cells. The bonds between the cells are weaker than before fermentation and a moderate shear is sufficient to separate the cells from each other, avoiding the formation of aggregates.

One way to treat fermented pulps is to lower the dry matter content of the pulps from 15-35% to 1-10% by adding water or white water from the paper manufacturing circuits. Subsequently, the suspension is subjected to mechanical treatment. The mechanical treatment can be carried out with different devices and the resulting product preferably has a distribution of its dimensions which makes it ideally suitable for use in the production of paper or cardboard. The treatment can be shearing or grinding. Known beet pulp treatments such as alternate compression and decompression and so-called "steam explosion" are not necessary. The mechanical treatment can be carried out directly during the mechanical pulping of the dough if a pulping or refining step is carried out. The use of the fermented beet pulps of the invention therefore does not require significant investment in most of the existing paper production installations.

Beet pulps have an ivory white color and become greyish due to enzymatic phenomena or degradation by heat. For paper applications, it is important that the fermented beet pulps can be blanched without losing essential mechanical properties. The present invention reveals that such a blanching does not adversely modify the characteristics of the fermented beet pulps.

The heterogeneous suspension can be bleached with H2O2 or NaCIO when a whiter product is desired; in this case, the bleaching agent can be added directly during the dilution of the fermented pulps preceding the mechanical treatment.

The heterogeneous material obtained, consisting of separate cells and short xylem and phloem fibers, was used in a pulp formulation; laboratory formulas were shaped and their properties evaluated in comparison with a control.

The present invention describes a paper or cardboard composition comprising fermented beet pulps. Fermented beet pulps are used as an organic ingredient that improves the strength characteristics of the finished product. The amount of fermented beet pulp is 0 to 50% and preferably between 2 and 25% by weight of the dry matter of the ingredients of paper or cardboard. The optimum quantities of fermented beet pulp added depend on the type of paper or cardboard produced and their desired characteristics. It has been shown that replacing 15% of waste paper with fermented beet pulp is feasible.

The fermented beet pulps are preferably prepared according to the process of the invention. The process of the invention does not employ chemical treatment of the fermented beet pulps. The process makes it possible to manufacture paper and cardboard without producing additional chemical waste.

The properties of the final paper sheets differ in complex ways depending on the type of wood pulp tested. In general, there are improvements in opacity, length at break, tear strength and "Dennison". At the same time, the drip time and the Shopper Riegler indices are increased for all the samples while the Bendtsen porosity is greatly reduced, and finally the gloss is less while bleaching as described above leads to an improvement. .

The present invention reveals that the resistance of paper and cardboard obtained by adding a certain amount of fermented beet pulp is considerably increased. It is preferable to master the reduction in the dimensions of the fermented beet pulps before using them in the preparation of the dough, so as to avoid the excessive increase in the draining time of such a dough. It has been shown that the preferred diameter of the fermented beet pulps is less than 1000 micrometers and more particularly from 150 to 250 micrometers for the preparation of corrugated cardboard.

Example 1 teaches that before using the fermented beet pulps, it is necessary to check whether the fermentation has been carried out, that is to say if the fermented product has not been degraded. The pH and the amount of lactic acid formed are possible measures of the condition of beet pulp. A formulation of the ingredients of the acidic paper type was used to prepare sheets of paper. The composition of the paper was changed so that 10% of the fibers were replaced by fermented beet pulp.

In Example 1, the resistance of the paper expressed in terms of breaking length, internal cohesion and tear resistance is considerably increased. Example 2 shows that it is possible to easily adapt the composition of the paper pulp in the case where it is necessary to use fermented beet pulps in an existing paper manufacturing process. The various means of mechanical processing of the paper pulp do not have a critical influence on the characteristics of the paper obtained. In Example 3, the use of fermented beet pulp was evaluated as an additive substitute in the manufacture of corrugated cardboard. If 10% dry matter of fermented beet pulp is used with 90% dry matter of a formulation without wood pulp, we obtain cardboard with the desired resistance characteristics. Since the fermented beet pulps have an adverse effect on the gloss of the finished product, it was assessed whether the bleaching of the product containing the fermented beet pulps was possible without adversely affecting the strength characteristics. As can be seen in example 4, the Tear strength and length at break remain high after laundering.

The examples show that the resistance of the finished product, paper or cardboard, increases considerably with the addition of fermented beet pulps. On the other hand, the draining time of the paper composition becomes longer.

Example 5 shows that when the fermented beet pulps are crushed and sieved and then mixed with old paper, the draining time is only slightly increased (sample 2) compared to the old paper which is subjected to pulping. traditional (control), if the diameter of the product is between 150 and 250 micrometers. It can also be seen that the strength properties are influenced by the size of the fermented beet pulps. The sieving of fermented beet pulps leads to resistance properties slightly lower than those of unscreened fermented beet pulps, but both are considerably higher than the values measured on the wood pulp.

This example shows that the beet pulps strongly influence the draining time and the resistance properties. It has been shown that the product obtained, containing fermented beet pulps, has appreciable physical characteristics with only a small increase in the draining time.

Finally, Example 6 shows that cationic flocculants with high molecular weight, usually used for the treatment of waste water are effective as drainage additives. The suspension of beet pulp flocculated by these chemicals leads to a paper composition having a considerably reduced draining time compared to that of a paper composition containing non-flocculated beet pulps. The expression "reduced draining time" corresponds to the draining time of a paper composition in which there is no beet pulp.

These flocculants are very effective despite the dimensions of the refined beet pulp. A further improvement in drainage time can be obtained by adding the flocculants to the sifted beet pulps so as to combine the effects of Examples 5 and 6, namely the sieving of the beet pulps and the use of a flocculant.

The invention relates to the use of fermented sugar beet pulps for the preparation of paper or cardboard. According to an advantageous embodiment, the invention relates to a composition of fermented sugar beet pulps as obtained by the process comprising the following steps: a) sugar beet pulps are ensiled under suitable conditions to give rise to lactic fermentation, and in particular until the pH is less than approximately 5 and advantageously greater than approximately 3.5 in order to obtain fermented pulps, b) the fermented pulps are diluted, in particular until the material content dry is from about 1% to about 10%, c) the diluted fermented pulps are subjected to a mechanical treatment, in particular a shearing, making it possible to separate the parenchymal cells contained in the pulps and to obtain a dimension of the pulps less than approximately 1000 micrometers, d) optionally: - the fermented pulps obtained at the end of step a) to a simultaneous blanching in step b), or

- the fermented pulps obtained at the end of step c) to bleaching. The addition of flocculant can be done at the end of step c) defined above, that is to say at the end of the shearing of the fermented pulps. According to another advantageous embodiment, the invention relates to a composition of fermented sugar beet pulps defined above as obtained by a process comprising the steps defined above, in which the ensilage is carried out with pulps sugar beet with a dry matter content of about 15 to about 35%. According to another advantageous embodiment, the invention relates to a composition of fermented sugar beet pulps defined above, in which the size of the beet pulps is less than 250 micrometers, and in particular less than 150 micrometers.

The invention also relates to a process for the preparation of a composition of fermented sugar beet pulps comprising the following steps: a) silage of sugar beet pulps under suitable conditions to give rise to lactic fermentation, and in particular up to 'the pH is less than about 5 and advantageously more than about 3.5 to obtain fermented pulps, b) the fermented pulps are diluted, in particular until the dry matter content is approximately 1% at around 10%, c) the diluted fermented pulps are subjected to a mechanical treatment, in particular shearing, making it possible to separate the parenchymal cells contained in the pulps and to obtain a pulp dimension of less than approximately 1000 micrometers, d) optionally subject:

- the fermented pulps obtained at the end of step a) to a simultaneous blanching in step b), or

- the fermented pulps obtained at the end of step c) to bleaching. According to another advantageous embodiment, the invention relates to paper or cardboard comprising from approximately 1 to approximately 50% and preferably from approximately 2 to approximately 25%, expressed relative to the dry materials, of a pulp composition of sugar beet fermented according to the invention.

According to another advantageous embodiment, the invention relates to paper or cardboard defined above, characterized in that the fermented sugar beet pulps have a size of less than 1000 micrometers, and preferably ranging from approximately 150 to approximately 250 micrometers.

According to another advantageous embodiment, flocculants can be added to the suspension of fermented beet pulps used for papermaking. These flocculants are chosen from those available on the market, more particularly on the market for waste water treatment products. More specifically, the high molecular weight cationic polymers are effective in improving the drainage of the paper preparation.

According to another advantageous embodiment, the invention relates to paper or cardboard defined above, characterized in that the fermented sugar beet pulps are blanched.

The invention also relates to a process for preparing paper or cardboard according to the invention, characterized in that: a) sugar beet pulps are ensiled under conditions suitable for giving rise to lactic fermentation, and in particular up to that the pH is less than about 5 and advantageously more than about 3.5 to obtain fermented pulps, b) the fermented pulps are diluted, in particular until the dry matter content is approximately 1% to approximately 10%, c) the diluted fermented pulps are subjected to a mechanical treatment, in particular shearing, making it possible to separate the parenchymal cells contained in the pulps and to obtain a pulp dimension of less than approximately 1000 micrometers, d) optionally:

- the fermented pulps obtained at the end of step c) in a bleaching process, e) at a rate of about 1 to about 50%, and preferably about

2 to around 25%, expressed relative to dry matter, of the above composition obtained at the end of step c) or d) to the traditional raw materials of paper pulp or cardboard,

- Optionally adding a flocculant after step c) or step e), preferably after step c).

The addition of flocculant can be done at the end of step c) defined above, that is to say after the shearing of the fermented pulps or after step e), it is that is to say after incorporating the diluted fermented pulps sheared into the traditional materials of paper pulp or cardboard. Preferably, the addition of the flocculant is done at the end of step c).

The invention also relates to a process for preparing paper or cardboard according to the invention, characterized in that: a) sugar beet pulps are ensiled under conditions suitable for giving rise to lactic fermentation, and in particular up to that the pH is less than about 5 and advantageously more than about 3.5 to obtain fermented pulps, b) the fermented pulps are diluted, in particular until the dry matter content is approximately 1% to approximately 10%, c) there is incorporated in an amount of about 1 to about 50%, and preferably about 2 to about 25%, expressed relative to the dry materials, of the composition obtained at the end of step b ) to the traditional raw materials of paper pulp or cardboard, d) possibly:

the composition obtained at the end of step c) to bleaching, e) a pulping or refining of the composition obtained at the end of step c) or d) is carried out in combination with a mechanical treatment , in particular shearing, allowing the separation of the parenchymal cells contained in the fermented beet pulps and obtaining a pulp size of less than about 1000 micrometers,

- Optionally adding a flocculant after step c) or step e), preferably after step c). In the above and what follows, the opacity is defined with respect to DIN 53146, the gloss is defined with respect to DIN 53145 part II, the length at break is defined with respect to DIN 53112 Part I, internal cohesion is defined with respect to DIN 54516, tear resistance is defined with respect to DIN 53115, Bendtsen porosity is defined with respect to DIN 53120 Part I, CMT is defined by compared to DIN 53143, Dennison is defined in the TAPPI Journal 459om-88, the draining time and the degree of refinement are defined in the Zellcheming Journal No. V / 7/61.

Example 1

Fermented beet pulp

The composition of the fermented beet pulps ensiled in Italy during the 1994 marketing year was analyzed to know if they had undergone a good lactic fermentation. The following data were obtained:

Table 1 Fermented beet pulps

Dry matter 26.50%

Ash 1.38% pH 3.6

Nitrogen 1.66%

Lactic acid / dry matter 8, 65% Lactic acid / total acids 71, 00%

These data show that the beet pulps have undergone good lactic fermentation. The pulps were then diluted to 2% of dry matter and sheared in an Ika Ultra Turrax mixer. The dimensions after shearing of the fermented pulps were measured with a series of Prolabo sieves in comparison with fresh pulps. The results which appear in Table 2 show the favorable effect of fermentation on the ease of disintegration of beet pulps. Table 2

Fresh pulps Fermented pulps

Shearing time 2 min 2 min

Pulp size (micrometers)% by weight% by weight d> 500 81, 8 27.2

500> d> 200 4.3 21.5

200> d> 125 0.7 3.7

125> d> 80 0.5 4, 1 d <80 12.7 43.5

Microscopic analysis of the suspension obtained clearly showed the presence of separate parenchymal cells. At the same time, the phloem and xylem structures were cut into smaller pieces and short fibers of rootlets were obtained. The same kind of suspension was obtained after shearing more concentrated fermented beet pulps (7% dry matter) with a Frima colloid mill. The latter equipment therefore seems to be best suited for industrial application in paper mills which do not have a refining stage.

It has been found that with a double disc refiner, for example of the type produced by Sprout Walden, suspensions of even more concentrated beet pulp could be refined. It has even been possible to refine fermented beet pulps as they are, that is to say without any prior dilution (dry matter content of 20 to 30%). However, this last refining condition leads to a very viscous suspension which is difficult to use in the subsequent stages of papermaking.

A determined quantity of this suspension was dehydrated with ethanol in order to have a reference stock of dried fermented beet pulps. This stock was used as a reference material in subsequent tests relating to the quality of the paper, in order to have identical standard properties. Two series of laboratory formulas were shaped and tested: the control and the MB. For the control, an acid paper formulation was used, prepared as described in Table 3, while, for MB, 10% of the fibers of said formulation were replaced by a sample from the reference stock. Table 3

In the table above, the long fibers come from soft wood such as pine wood and have a dimension of approximately 3.5 to 4.8 mm and the short fibers come from hard wood such as birch wood and have a dimension of about 0.7 to about 1.7 mm.

The sample was prepared by mixing short and long fibers and beet pulps in the proportions indicated. The degree of refinement was that indicated in Table 3. The characteristics of the papers obtained are determined by standard methods. The sample containing beet pulps from the reference stock, MB, showed a significant improvement in the resistance indices and a slight increase in the draining time while the porosity was significantly reduced.

The use of a reference stock has proved to be very useful because, with a stable and readily available stock of material, it becomes possible to determine the relationship between the characteristics of the paper and the fermentation conditions of the beet pulps. Example 2

Refining of fermented beet pulps for quality paper.

The fermented beet pulps were processed with an Escher Wiss refiner to check if the equipment normally used in a paper mill is effective enough to separate the parenchymal cells from the beet pulps without at the same time breaking the cells. The following tests have been carried out:

Table 4

* Note: the witness consists of a formulation without wood pulp prepared with unselected corrugated paper plumped up to 30 ° SR.

Sample P showed the presence of rather large pieces while the other two samples, PR and MR, had pieces having dimensions comparable to those of the tests with the colloid mill. The samples were evaluated, after the shaping of the formulas, having used for each of them 10% dry matter of fermented beet pulp and 90% of the formulation (*) without wood pulp. The data were compared with 100% of a formulation without wood pulp (control) (*) and with a sample, MB1, containing 10% of material from the reference stock and 90% of the formulation (*) without pulp of wood. Table 5

With regard to increasing the strength of the paper, it can be seen that there is not much difference between the various types of mechanical processing. However, a higher draining time is observed for the mixed pulp and refined (MR) sample. This result could be due to the increase in the soluble fraction released inside the pulps during the refining stage.

(*) Note: the witness consists of formulation without wood pulp prepared with unselected corrugated paper plumped up to 30 ° SR.

Example 3

Refining of fermented beet pulps to make fluted paper.

A few tests were carried out by mixing fermented beet pulps with old brown paper. The purpose of these tests was to determine whether the fermented beet pulps could improve the characteristics of the waste paper used to make fluted paper, without significantly modifying the preparation conditions.

High values of CMT (Concora Medium Test), rigidity, internal cohesion and burst pressure are obtained for fluted paper. addition of starch to waste paper during manufacture. Fermented beet pulps could be of economic interest as a starch substitute, provided that these pulps significantly increase the desired characteristics while at the same time reducing the amount of starch required. On the other hand, it should be avoided to increase some parameters such as the draining time, the SR degree, the COD, the conductivity and the turbidity during the shaping of the sheets of paper. The evaluation of the laboratory formulas was carried out with different dosages of fermented beet pulp (PBF) in the old paper (control).

Table 6

Poly Aluminum Chloride

Note: Indicator = brown paper obtained by repulping unselected corrugated paper.

It can be observed that with the increase in the quantity of beet pulps in this corrugated cardboard, the quality of the paper, defined by internal cohesion, the CMT 30 and the burst pressure, increases. It is also found that the porosity drops to 100 ml / min for the highest amount of beet pulp, that is to say 15%. No effect of the quantity of beet pulp on rigidity is observed.

The maximum amount of beet pulp possible in the manufacture of corrugated board seems to be 10% because of the high value of the resulting drip time. Further improvement of drip characteristics could increase the amount of beet pulp in the dough.

Example 4

Blanched fermented pulps.

Fermented beet pulp, ensiled after the 1993 campaign was mechanically sheared. H2O2 was added during dilution (4% based on dry matter). The suspension obtained was then used for tests of paper sheets (10% of blanched fermented beet pulps, 90% of the acid paper formulation described in Example 1) and the results are compared with a control (the same as in example 1) as shown below.

Table 7

The bleaching of the sample leads to better gloss compared to the unbleached product. In addition, good results are again observed with regard to the strength properties such as tear resistance, length at break and "Dennison". These data indicate that the use of fermented beet pulp is suitable for the production of white paper.

Example 5

Draining time of fermented beet pulp.

In the previous examples 2 and 3, the physical properties of the paper containing the fermented beet pulps were measured with test conditions. The paper / fermented beet pulp mixture was pulped and refined with processing times that were only suitable for improving the paper, but without optimizing the processing time for the beet pulps. In addition, no sieving step has been carried out, although this is necessary during the industrial production of paper. It is known that the dimensions of the paper fibers suitable for corrugated cardboard must be between 150 and 250 micrometers.

For these reasons, a test was carried out using a mixture containing 90% of pulped and refined waste paper and 10% of sieved fermented beet pulps ranging in size from 150 to 250 micrometers.

The result of this test is shown below.

Table 8

VP = waste paper obtained by repulping unselected fluted paper PBF = fermented beet pulp.

These data show that when the fermented beet pulps are crushed and sieved and then mixed with the waste paper, the draining time is only slightly increased (sample 2) compared to the waste paper which is subjected to traditional mechanical pulping (control ). The draining time of sample 2 is in fact comparable to that of the control, while it is more than three times lower than that of sample 1.

It can also be seen that the resistance properties are slightly affected by the dimensions of the fermented beet pulps. However, sieved fermented beet pulps have resistance properties comparable to those of unscreened pulps and both are considerably higher than the values found for wood pulp. This example shows that the dimensions of the beet pulps strongly influence the draining time and the resistance properties. It has been shown that a product is obtained containing fermented beet pulps which has appreciable physical properties and only a slight increase in the draining time.

Example 6:

Use of flocculants as dripping aids:

Example 5 shows that the use of sieved fermented beet pulps ranging in size from 150 to 250 micrometers nevertheless leads to an increased draining time, although this increase is much less than when using pulp of unsifted fermented beets.

Another way to reduce drip time is to use flocculants. High molecular weight cationic flocculants are capable of flocculating the beet pulp suspensions used for papermaking. Among these, there may be mentioned: Zetag 89® from Allied Colloids, Bufloc 5327® and 5328® from Buckman, Floerger 4698® from SNF Floerger and products from the company Nalco. The use of flocculated beet pulps for papermaking leads to correct draining times. However, the extent of this improvement depends on several factors such as the shear of the paper suspension during manufacture, the amount of flocculant and the manner of use of the flocculant.

The draining time of a paper composition containing 89.5% waste paper, 10% fermented beet pulp and 0.5% flocculant

(Floerger 4698® from SNF Floerger) was measured with the Techpap drip jar at different shear times (Figure 1).

Figure 1 shows that the drip time is a function of the shear time when adding a flocculant. At low shear, the mixture of waste paper and flocculated beet pulp drips better than waste paper alone.

The laboratory formulas obtained by the use of flocculated beet pulp were physically characterized. As can be seen in Table 9, the good strength properties were retained despite the flocculation. In addition, the use of flocculant leads to a significant reduction in the COD of the waste water. Table 9

VP: old paper,

PBF: fermented beet pulp.

Claims

1. Use of fermented sugar beet pulps for the preparation of paper or cardboard.

2. Composition of fermented sugar beet pulps as obtained by the process comprising the following stages: a) sugar beet pulps are ensiled under appropriate conditions to give rise to lactic fermentation, and in particular until the pH is less than approximately 5 and advantageously greater than approximately 3.5 in order to obtain fermented pulps, b) the fermented pulps are diluted, in particular until the dry matter content is approximately 1% to approximately 10 %, c) the diluted fermented pulps are subjected to a mechanical treatment, in particular shearing, making it possible to separate the parenchymal cells contained in the pulps and to obtain a pulp size of less than about 1000 micrometers, and optionally the addition is carried out a flocculant, d) optionally subject:

- the fermented pulps obtained at the end of step c) to bleaching.

3. Composition of fermented sugar beet pulps according to claim 1, as obtained by a process comprising the steps of claim 2, in which the ensilage is carried out with sugar beet pulps whose dry matter content is about 15 to about 35%.

4. Composition of fermented sugar beet pulps according to one of claims 2 or 3, in which the size of the beet pulps is less than 250 micrometers, and in particular less than 150 micrometers.

5. A process for the preparation of a composition of fermented sugar beet pulps comprising the following steps: a) the sugar beet pulps are ensiled under appropriate conditions to give rise to lactic fermentation, and in particular until the pH be less than about 5 and advantageously more than about 3.5 to obtain fermented pulps, b) the fermented pulps are diluted, in particular until the dry matter content is from approximately 1% to approximately 10%, c) the diluted fermented pulps are subjected to a mechanical treatment, in particular shearing, making it possible to separate the parenchymal cells contained in the pulps and to obtain a pulp dimension of less than approximately 1000 micrometers, d) optionally subject: - the fermented pulps obtained at the end of step a) to a simultaneous bleaching in step b), or

- the fermented pulps obtained at the end of step c) to bleaching.

6. Paper or cardboard comprising from approximately 1 to approximately 50% and preferably from approximately 2 to approximately 25%, expressed relative to the dry matter, of a composition of fermented sugar beet pulps according to one of claims 2 to 4.

7. Paper or cardboard according to claim 6, characterized in that the fermented sugar beet pulps have a size less than 1000 micrometers, and preferably ranging from about 150 to about 250 micrometers.

8. Paper or cardboard according to one of claims 6 or 7, characterized in that the fermented sugar beet pulps are blanched.

9. A process for preparing paper or cardboard according to one of claims 6 to 8, characterized in that: a) sugar beet pulps are ensiled under appropriate conditions to give rise to lactic fermentation, and in particular up to the pH is less than about 5 and advantageously more than about 3.5 to obtain fermented pulps, b) the fermented pulps are diluted, in particular until the dry matter content is approximately 1% to approximately 10%, c) the diluted fermented pulps are subjected to a mechanical treatment, in particular shearing, making it possible to separate the parenchymal cells contained in the pulps and to obtain a pulp dimension of less than approximately 1000 micrometers, d) optionally:

- the fermented pulps obtained at the end of step c) in a bleaching process, e) incorporated at a rate of approximately 1 to approximately 50%, and preferably approximately 2 to approximately 25%, expressed relative to the dry matter, of the above composition obtained at the end of step c) or d) to the traditional raw materials of paper pulp or cardboard, - a flocculant is optionally added at the end of step c) or from step e), and preferably at the end of step c).

10. A process for the preparation of paper or cardboard according to one of claims 6 to 8, characterized in that: a) sugar beet pulps are ensiled under appropriate conditions to give rise to lactic fermentation, and in particular up to the pH is less than approximately 5 and advantageously greater than approximately 3.5 to obtain fermented pulps, b) the fermented pulps are diluted, in particular until the dry matter content is approximately 1% to about 10%, c) there is incorporated in an amount of about 1 to about 50%, and preferably about 2 to about 25%, expressed relative to the dry materials, of the composition obtained at the end of the step b) traditional raw materials for pulp or cardboard, d) possibly:

the composition obtained at the end of step c) after bleaching, e) pulping or refining of the composition obtained at the end of step c) or d) is effected in combination with a mechanical treatment , in particular shearing, allowing the separation of the parenchymal cells contained in the fermented beet pulps and obtaining a pulp size of less than about 1000 micrometers,

- Optionally adding a flocculant after step c) or step e), and preferably after step c).