Paper and cardboard comprising starch- and protein-containing material

Paper and cardboard containing starch and protein fractions of flour having improved strength, stiffness and surface properties, wherein the starch and protein fractions are subjected to a degradation with ammonium persulfate, amylase, an acid, protease or a combination thereof before being introduced to the paper or cardboard. After the starch and protein fractions have been degraded, they can be added to the paper fiber matrix or used as a sizing or glue.

The invention resides in the field of paper and cardboard manufacturing. In 
particular, the invention relates to the use of a combination of starch- 
and protein-containing material in paper and cardboard. In fact, in this 
specification and the claims, the term `paper` is meant to include 
cardboard as well. 
Traditionally, starches are used on a large scale and in large volumes in 
the paper and cardboard industry. In the production of coated paper, which 
is substantially used as graphic paper in the fine-paper industry, it is 
used as, inter alia, binding agent in the coating. In general, this starch 
is a modified starch. 
In addition, starch is used as admixture for improving the strength 
properties, and in particular the dry-strength properties, of the paper. 
For that purpose, starches conventionally used in the paper industry and 
anionic and cationic derivatives of these starches are used, for which 
reference can be made to, for instance, EP-A-0 545 228 and WO-A-94/05855. 
In this connection, further reference can be made to Kirk-Othmer, 
Encyclopedia of Chemical Technology, Third Edition (1981), John Wiley & 
Sons, Volume 16, p. 803 ff, in particular pp. 814-819. 
In the most current uses of starch as fiber-reinforcing component, it is 
either introduced--usually in the form of cationic starch--into the mass 
of the paper in the wet portion of the paper process, or 
impregnated--substantially in the form of solubilized native starch--into 
the paper fiber mass by means of the so-called size press. 
These known strength-improving additives are advantageous, both in an 
economical and in a technical or technological sense; they give the paper 
or the cardboard an added value. Apart from providing an added value in 
conventional paper and cardboard processes, the need for additives for 
increasing the strength is enhanced in particular by the increasing use of 
weaker fibers, old paper that is reused more and more often, and a further 
increasing use of fillers instead of fibers in this old paper, resulting 
in a decreasing strength potential, and the decreasing availability of 
strong, long-fiber components in the base pulp for paper. 
Actually, it is now emphasized that the invention is not limited to 
"waste-based" paper. The invention extends across the entire area of paper 
and cardboard manufacture, including paper based on "virgin fiber". 
The known starch-based additives can enter into large-scale interactions 
with the cellulose groups of paper fibers. Thus, an increase of the number 
of bonds between the mutual paper fibers is formed, which reinforces the 
fiber-fiber bond and, accordingly, improves the strength properties of the 
final product. 
In conventional processes wherein starches are used as strengthener, strict 
requirements are imposed on the protein content that may be present in the 
starch product used. In particular, native starch used for the manufacture 
of paper, substantially native wheat-, corn- or potato starch, is supplied 
with an additional specification for maximum protein contents of 0.3-0.5 
wt. %, calculated on the dry substance. Higher protein contents are 
supposed to have a contaminating effect and to cause lump formation and 
depositions in the system. For instance, the dispersion of gluten (the 
protein fraction in wheat flour) leads to lumping and foam formation. 
These drawbacks occur to an enlarged extent when these proteins are 
exposed to higher temperatures in the paper manufacturing process. 
The starch which forms the basic material for presently used starch 
additives in paper is recovered from a large number of vegetable sources, 
for instance from grains, such as wheat, corn and rice; from tubers, such 
as potatoes and tapioca; or from other plant parts, such as sago. 
From the above-mentioned vegetable sources, the starch is released by the 
use of a combination of mechanical steps, purifying steps and drying 
steps. The separated protein-containing fractions, as well as other 
by-product fractions, are discharged. The starch purification involves the 
release of many waste flows, such as water flows containing biological 
material. These flows are increasingly becoming an environmental problem, 
so that draining without more is no longer possible. 
The preparation of the starch that is used in the paper industry in the 
largest amounts as fiber-reinforcing and paper-stiffening agent, viz. 
wheat starch, is described as example. Similar processes are carried out 
for rendering starch from other vegetable sources applicable to the paper 
industry. 
Wheat grains substantially consist of two components. The core, the 
so-called endosperm, largely consists of starch and protein. The outer 
layer, the brans or the chaff, mainly contains cellulose. The ratio 
core:outer layer is about 80:20. 
These wheat grains are ground, the chaff being separated from the core. The 
separated endosperm, consisting for about 70-80% of starch and for about 
10-15% of protein, is commonly designated by the term "flour". Depending 
on the extraction degree of the wheat, more or less pure flour is 
obtained. For instance, at an extraction degree of about 80%, "grey flour" 
is obtained, while at a somewhat lower extraction degree of about 70%, 
considerably purer flour is obtained, because at this extraction degree, 
no parts other than the endosperm end up in the flour. 
In the production of starch for the paper industry, the protein, in 
particular the gluten, is subsequently washed from the flour. The flour is 
thus separated into two main components. As indicated, in this process, 
economically unprofitable drying steps are carried out, a part of the 
starting substance wheat cannot be used, and waste flows are created that 
have to be processed. 
The primary object of the present invention is to provide a method wherein 
an optimized use is made of raw materials in the sense that a largest 
possible fraction of the raw material can be used in the paper process. 
This object is realized by introducing the components of flour into the 
manufacturing process of paper or cardboard completely, without this flour 
or flour components being priorly modified by binding cationic or anionic 
groups thereto or without such protein/starch mixtures being priorly 
dry-modified. In other words, the object is realized by starting from 
native protein/starch mixtures and using them as such. In this 
specification and claims, by "flour" is meant a protein- and 
starch-containing fraction originating from one and the same vegetable 
source, or a natural mixture of protein and starch. 
More in particular, the invention relates to paper or cardboard comprising 
the components of native flour in the paper fiber matrix. In addition, the 
invention relates to a method for manufacturing paper or cardboard wherein 
flour is substantially subjected to a treatment whereby starch and protein 
are solubilized, after which the treated components of flour are jointly 
introduced into the paper fiber matrix in one step. Moreover, the 
invention relates to a method wherein vegetable starch sources can be used 
entirely, hence without generating waste products, in the paper industry. 
Accordingly, the invention relates to paper of cardboard comprising protein 
and starch, at least partly originating from the same source, in the paper 
fiber matrix. Further, the invention relates to paper or cardboard into 
which all components from vegetable starch/protein sources have been 
processed. 
It has been found that by the use of an amount of flour according to the 
invention, paper can be obtained which has substantially the same 
properties as paper wherein about the same amount of starch is used. In 
other words, the function of a part of the conventionally required starch 
can be taken over by the protein fraction in flour, although the prior art 
merely teaches disadvantageous properties. In addition to economical 
advantages--flour is cheaper than starch prepared therefrom--, 
technological and environmental advantages are obtained as well, because 
no drying steps or purifying steps have to be carried out, and/or because 
no waste flows have to be discharged. 
The paper according to the invention preferably comprises at least 0.1 wt. 
%, more preferably at least 0.3 wt. %, and usually 0.3-8 wt. % starch and 
at least 0.03 wt. %, preferably between 0.05 wt. % and 2.4 wt. %, usually 
0.05-1 wt. % protein in the paper fiber matrix, calculcated on the weight 
of the dry substance. If less than the minimum contents of protein and 
starch are used, the advantages obtained according to the present 
invention are too slight or other conventional auxiliary substances are 
required for obtaining the desired paper properties. It is true that if 
more than 8 wt. % starch and more than 1 wt. % protein is used, paper of a 
very high added value is obtained, but from a business-economical 
viewpoint, the process is often less attractive. 
Preferably, 2-5 wt. % starch in addition to 0.2-1 wt. % protein is 
introduced into the paper fiber matrix, because this combines the 
advantages of the invention with a favorable production price. 
In accordance with the present invention, the protein and starch fraction 
at least partly originates from one and the same vegetable source. As 
vegetable sources that can be used for this purpose, those having a high 
content of starch next to protein can be mentioned, for instance seeds, 
such as beans, peas and grains, for instance wheat, corn and rice grains; 
and other protein- and high starch-containing plant parts. In the present 
specification and claims, these products are designated by the term 
"flour". 
Preferably, flour originating from grains or pulses, preferably wheat 
flour, is introduced into the fiber mass of the paper or cardboard. A 
great advantage of the use of flour originating from grains and pulses is 
that from an economical viewpoint, for use in accordance with the present 
invention, this raw material is more attractive than the starch that is 
normally used. For instance, at this moment, the cost of wheat flour are 
about half the cost of native wheat starch. 
Further, because of the omission of the separation of flour into a starch 
and protein component, the energy consumption is reduced considerably, 
partly because no drying steps have to be carried out. 
Flour originating from grains or pulses, and in particular wheat flour, is 
used in amounts of preferably 2-5% calculated on the dry mass. 
Wheat flour cannot be introduced into the paper as such. If this is 
attempted, the drawbacks known from the prior art--high degree of 
deposition, lumping, dough formation, foam formation--occur. The problems 
prove not to occur when the flour is at least subjected to a treatment 
known for native starch in the paper industry. 
As a skilled person knows, for use on the size press, a product dissolved 
in water and having a Brookfield viscosity of less than about 100 cP is 
required. Such a solution (it is suitable to start from a 10 wt. % flour 
suspension) can be obtained by treating wheat flour with a chemical and/or 
enzymatic starch chain-degrading agent to obtain a viscosity in the 
above-mentioned range. For instance, flour can be subjected to a 
degradation with ammonium persulfate (APS), known for native starch, 
optionally in the presence of an acid, for instance acetic acid or citric 
acid. The presence of acid in this embodiment is for instance needed if 
wheat flour is started from, which is illustrated in Example 2. Other 
methods are treatments with amylases or combinations thereof with APS, 
optionally complemented with a protein-modifying step. 
Whereas for an interference-free size press treatment, the viscosity of 
native starch solutions known from the prior art is preferably between 
about 30 and 80 cP, a viscosity as low as only 15 cP is sufficient when 
flour is used. From Example 1 below, it appears that this produces a paper 
of the same quality as in the case where only starch is used. 
In fact, it is also possible to eliminate interfering properties caused by 
the protein component in flour by substantially degrading this protein 
component and, accordingly, only utilizing the starch component 
effectively. 
However, this embodiment lacks a number of the advantages of the present 
invention. 
Dutch patent application 1001218 describes that proteins can improve the 
strength properties of paper and cardboard and, in addition, have a large 
number of advantages when they are present in the paper fiber matrix. In 
particular, proteins inter alia provide, apart from improved stiffness 
values, SCT--("Shortspan Compression Test"), RCT--("Ring Crush Test"), and 
CMT--("Concora Medium Test") values--and strength values--inter alia burst 
pressure, tensile strength--, which values are a measure for specific 
strength properties of the paper, in particular for the production of 
corrugated board, optimization possibilities and improvements in other 
constructional paper properties, such as stiffness, in properties of 
processability, such as foldability and scoring facility, and in 
functional properties, such as permeability to gases and liquids. 
Moreover, the use of proteins in paper manufacturing provides optimization 
possibilities and improvements in the field of general process control, 
usability of raw and auxiliary materials, and energy demand. Further, the 
above-mentioned properties can be controlled depending on the 
manufacturing conditions and conditions of application, for instance 
climatological conditions, without this being at the expense of the 
reprocessability of the paper product and the output of the production 
process. 
In accordance with the present invention, it has now been found that the 
advantages mentioned in Dutch patent application 1001218 can also be 
obtained by the use of flour components in paper. For that purpose, not 
only the one-step treatment as known for native starch should be carried 
out, but a second treatment should be carried out as well. For the use of 
wheat flour with the size press, this second treatment is a deamidation 
reaction and/or a partial proteolysis. This second treatment renders the 
wheat gluten more water-soluble and can be carried out in a 
thermo-chemical manner (warming by acid) as well as in an enzymatic manner 
(protease). 
In a preferred embodiment, the wheat flour is treated with acid APS at a 
temperature of about 85-95.degree. C. In addition to the degradation of 
the starch, this treatment provides at the same time a processing of the 
protein. 
As appears from the examples given below, synergistic effects occur when a 
starch/protein mixture prepared in an unseparated manner is used in 
conformity with the invention. The effect of flour on the strength and 
stiffness properties of paper is as great as and sometimes even greater 
than the effect of an approximately equally large weight fraction of 
conventionally treated and used, native starch. 
It has been demonstrated that by introducing protein and starch molecules 
into the paper fiber matrix, in particular the stiffness and strength 
properties can be positively modified and controllably influenced. 
These paper properties are not only important in respect of wrapping papers 
based on recirculated material, but also in respect of solid cardboard and 
various types of paper based on "virgin fiber". 
For obtaining a good paper product, it is essential that the protein and/or 
starch molecules be present in the paper sheet. After all, the 
optimization of the fiber-fiber bond of the paper, whereby the resulting 
advantages can--probably--be explained, can only take place when 
sufficient protein and/or starch material is present on, in and between 
the fibers. In this manner, the paper fiber mass and the protein and 
starch fraction form a whole; no clearly sharply delimited protein and 
starch masses and paper fiber masses are distinguished. 
The advantageous effects of the use of protein in combination with starch 
in the bulk of the paper are dependent, sometimes even to a high degree, 
on the place or manner of applying and/or the nature of the protein 
introduced. After taking cognizance of the specification of the present 
invention, it will be within the scope of a skilled person to adjust the 
paper-manufacturing process, including the raw and auxiliary materials to 
be used, depending on the wishes of the customer/user and the conditions. 
These above-mentioned flour-processing methods generally and mainly bring 
the protein fraction into solution, while the starch is solubilized and 
degraded. The treatment of the flour can be carried out batchwise as well 
as continuously-in-line. 
The invention further relates to a method for manufacturing paper or 
cardboard, comprising at least a step wherein proteins and starch, i.e. 
the product as it is recovered from a natural product as unseparated 
vegetable protein/starch mixture, optionally after being subjected to the 
above-elaborated treatment analogously with the treatment carried out with 
native starch, is introduced into the paper fiber matrix. 
In conventional paper-manufacturing processes the first treatment consists 
in so-called pulping--preparing pulp by suspending fiber materials in 
paper that may or may not have been circulated. In a large vat, by the use 
of mechanical energy, usually by stirring, and heating, usually with steam 
or warm water, fiber material is added to water. Through the mechanical 
and physical treatment, the fiber material is dissolved or dispersed to 
create a liquid mash, the pulp. Next, the pulp is subjected to a number of 
treatments. For instance, the pulp is cleaned, with unusable, nonfibrous 
material being removed from the pulp. Moreover, if necessary, a fiber 
treatment, such a grinding, is carried out. Finally, the pulp is presented 
in a specific concentration to the paper machine which manufactures paper 
from the pulp. 
In accordance with the invention, during the method for manufacturing 
paper, at least a step is carried out whereby proteins and starch are 
jointly introduced into the paper fiber matrix. 
During the process pass from pulp vat to paper machine, auxiliary 
substances, including the protein-starch mixture used according to the 
present invention, preferably wheat flour, can be added. Moreover, after 
sheet formation, the protein and starch material can be provided thereon 
and then--by performing specific treatments--introduced into the fiber 
matrix. 
For instance, during the paper sheet formation, protein-starch solutions 
can be introduced into the paper layer or between different paper layers, 
if any, for instance through spraying or foaming. Also, the protein-starch 
material can be introduced into the fiber mass by means of a surface 
treatment or impregnation of the paper already formed, for instance and 
preferably by means of a size press treatment. Finally, reference is made 
to the possibility of applying protein material to the dry paper web 
through spraying or other known application techniques. 
In a preferred embodiment of the method according to the invention, 
protein-starch mixtures are introduced into the paper by means of a size 
press treatment. During the size press treatment--a treatment which is 
generally used in the paper industry and is therefore known to a skilled 
person--a solution or suspension containing the protein-starch mixture to 
be used is pressed into the paper by means of rolling. The size press 
treatment can be carried out single-sidedly on the top or bottom side of 
the paper web, as well as double-sidedly. 
In particular for use in the size press, higher protein and starch 
concentrations have advantages with regard to the maximally feasible 
properties and reduced drying energy thus required. 
In the above-mentioned techniques, it is always important that at least a 
part of the proteins and the starch be brought into close contact with the 
fibers in the paper fiber matrix. 
Further, it is possible to introduce, in addition to the joint introduction 
of a protein/starch mixture, supplementary amounts of starch or protein. 
This can take place at the same place by the use of the same technique, 
but also at other places in the paper-preparing process. 
The invention relates to the use of flour components in the fiber matrix of 
paper for improving and directing paper properties such as strength, 
stiffness, permeability, surface properties and elasticity. Moreover, the 
flour fraction treated according to the invention can be used as glue for 
fixing the corrugations in corrugated cardboard. 
The invention also relates to the use of protein- and starch-containing 
materials wherein, for attaining the desired paper properties, only the 
starch fraction is modified chemically or enzymatically. If the starting 
material contains, in addition to starch, for instance water-soluble 
proteins, it is not necessary to modify these proteins in order to produce 
a size having good processing and reinforcing properties. An example 
hereof is pea meal of which the proteins are soluble in an alkaline 
medium. 
Moreover, for reinforcing the paper, it is possible to use only the starch 
fraction of starch- and protein-containing materials. On the one hand, 
this can be effected on account of the fact that the protein, without 
modification, is water-soluble so that it is either pressed through the 
paper during the paper treatment, or, present in the paper matrix, does 
not contribute to the paper properties. On the other hand, the protein can 
be modified too far, as a consequence of which it does not contribute to 
the paper properties either. In the most extreme case, the protein is 
degraded into amino acids. An advantage hereof is that no sharply 
delimited processing degree of the protein has to be set, so that the 
conversion of starch- and protein-containing material into the suitable 
size is not a very critical process. 
Finally, the invention relates to a method for manufacturing paper wherein 
vegetable material having as main components protein and starch, 
preferably grain, is completely processed, comprising separating the 
vegetable material into (a) a fraction substantially consisting of the 
cellulose material and (b) a fraction substantially consisting of the 
protein and starch material, feeding fraction (a) to the usual starting 
paper fiber mass, for instance during the preparation of pulp, and feeding 
fraction (b) in the step wherein fiber-reinforcing additives are 
introduced. The fraction fed in the step wherein fiber-reinforced 
additives are introduced is treated in conformity with the above-described 
method. In particular, in this aspect of the invention it is possible to 
completely grind up a vegetable protein and starch source, for instance 
wheat, and to use the ground-up product directly--after a modification 
that is analogous with native starch and optionally after a modification 
wherein the protein properties are optimized--as fiber-reinforcing, 
quality-improving component, and to use the residual products, such as the 
chaff, directly as fiber material. The modification of the flour can 
consist of a thermochemical conversion, for instance with APS and/or acid, 
for instance citric acid, optionally in combination with an enzymatic 
modification with, for instance, amylase and/or protease.

Presently, the invention will be specified with reference to the following 
examples. 
EXAMPLE 1 
In this example, the effect of the use of flour (IJsvogel-flour, Meneba 
Nederland; moisture content 13.5%; about 10 wt. % gluten and about 89.5 
wt. % starch calculated on the dry product) was studied. For that purpose, 
suspensions of flour and--for comparison--native starch were introduced 
into paper by means of the size press method. 
The solutions of the above-mentioned macromolecules were set at a desired 
viscosity by subjecting both the starch fraction and the flour fraction to 
a degradation with ammonium persulfate (95.degree. C.). For an 
interference-free size press application, the viscosity of the starch 
suspension should be between 30 and 80 cP; good results with the flour 
suspension are already obtained at a viscosity of only 15 cP. 
The macromolecules-containing solutions were introduced into paper 
(recycled paper; D-Liner; Roermond Papier) by means of a laboratory size 
press (Einlehner, rate 30 m/min, temperature 70.degree. C., pressure 2 
bar). 
The SCT-value and the burst factor were determined according to 
standardized requirements. 
The SCT-value is the maximum compression force per width unit that a test 
strip can undergo under defined conditions until this strip becomes upset. 
In this example, the SCT-determination was carried out perpendicularly to 
the machine direction of the paper. The SCT-value is expressed in kN/m. 
The burst factor is determined from a burst pressure measurement. The burst 
pressure is the pressure exerted on a piece of paper at the moment when 
the paper cracks. The burst factor (expressed in kPa) is equal to the 
burst pressure multiplied by 100 divided by the basic weight (g/m.sup.2). 
The results are stated in the following table. 
TABLE 1 
______________________________________ 
Increase of the SCT-value and the burst factor 
relative to the control during the use of flour or starch 
SCT-value (kN/m) 
burst factor (kPa) 
______________________________________ 
starch 0.75 48 
flour 0.65 42 
______________________________________ 
It has been found that the use of flour gives almost the same increase in 
SCT-value and burst factor as starch. Moreover, a further influencing of 
the strength properties can be obtained by using a flour suspension having 
a different viscosity. 
EXAMPLE 2 
Pretreatments of Flour Slurries 
A) Treatment with Neutral APS 
A suspension of 694 g IJsvogel-flour in 1306 g water (50.degree. C.) was 
stirred in a beaker. 2.16 g APS was added, followed by stirring for 
another 30 minutes at 50.degree. C. The resulting solution was diluted to 
a 10 wt. % solution. Heating at 75.degree. C. took place for 30 minutes, 
after which the whole was boiled for another 60 minutes in a water bath. 
B) Treatment with Acid APS 
A suspension of 232 g IJsvogel-flour in 1309 g water was stirred in a 
beaker. Citric acid was added to a pH of 4, after which 0.72 g APS was 
fed. After that, the mixture was allowed to boil for 60 minutes in a water 
bath. 
C) Treatment with APS and Protease 
A suspension of 694 g IJsvogel-flour in 1306 g water (50.degree. C.) was 
stirred in a beaker. 1000 .mu.l Neutrase (NovoNordisk) was added, followed 
by stirring for another 30 minutes at 50.degree. C. The resulting solution 
was diluted into a 10 wt. % solution. 2.16 g APS was added. The whole was 
boiled for 60 minutes in a water bath. 
D) Treatment with Amylase and Protease 
A suspension of 694 g IJsvogel-flour in 1306 g water (50.degree. C.) was 
stirred in a beaker. 933 .mu.l Ban .alpha.-amylase and 1000 .mu.l Neutrase 
(both NovoNordisk) were added, followed by stirring for another 30 minutes 
at 50.degree. C. The resulting solution was diluted to a 10 wt. % 
solution. For 30 minutes the temperature was increased to 75.degree. C. 
After that, the whole was boiled in a water bath for another 30 minutes. 
Of the four slurries A-D treated, the Brookfield viscosity was determined 
in cP. The measuring results are shown in the following table. 
TABLE 2 
______________________________________ 
Brookfield viscosity (cP) 
______________________________________ 
A APS -- 700 
B APS citric acid 
40 
C APS protease 40 
D .alpha.-amylase 
protease 25 
______________________________________ 
The flour solutions having viscosities lower than 100 cP could readily be 
processed on the size press. 
EXAMPLE 3 
With a flour slurry obtained according to method D in Example 2 and a 10 
wt. % standard starch slurry, test sheets (Testliner 3 Roermond Papier, 
160.times.100 mm) were treated on a laboratory size press (Einlewner, rate 
30 m/min, temperature 70.degree. C., pressure 2 bar). The impregnated 
sheets were dried on a drying cylinder at 130.degree. C. 
Of these test sheets, the paper properties were determined under 
conditioned circumstances (23.degree. C., 50% RV) according to 
standardized methods. The measuring data are stated in the following 
table. 
TABLE 3 
______________________________________ 
Strength and stiffness properties 
activity 
paper starch flour rel. to 100% 
property (standard) 
(enzymatic) 
starch 
______________________________________ 
take-up (%) 3.2 3.2 
burst factor 241 273 +13% 
(kPa) 
breaking 6454 6915 +7% 
length (m) 
stretch (%) 1.93 2.13 +10% 
SCT (140 g) 2.46 2.76 +12% 
(kN/m) 
stiffness 1022 1036 +1% 
(kNm) 
CMT 30 (140 g) N 
278 284 +2% 
______________________________________ 
In this table, "take-up" is the weight percentage flour/starch relative to 
the dry paper. 
EXAMPLE 4 
Use of Pea Meal 
The proteins in pea meal are water-soluble. From pea meal, a flour size is 
made by modifying only the starch. In a number of experiments, the starch 
in pea meal is degraded by means of APS or enzymes. 
TABLE 4 
______________________________________ 
size viscosity 
treatment (cP) SCT-value (kN/m) 
______________________________________ 
APS 150 riot determined 
APS + citric 30 4.2 
acid 
BAN 80 4.2 
Termamyl 60 4.4 
______________________________________ 
If a suspension of pea meal is only treated with APS, the suspension 
obtains a high viscosity, as a consequence of which the size is difficult 
to apply to paper. By reducing the pH of the suspension with citric acid, 
the APS becomes more effective, so that a size is obtained that does meet 
the Theological requirements. When this size is applied to paper, the 
SCT-value is increased. Also the enzyme BAN and Termamyl degrade the 
starch sufficiently in a suspension of pea meal to obtain a viscosity 
lower than 100 cP. During application to paper, the SCT-value is 
increased. 
EXAMPLE 5 
Test on Production Scale 
In a test reactor, a four slurry with enzymes (Neutrase) was suspended. 
Next, this slurry was thermochemically gelatinized with ammonium 
persulfate over a jet-cooker (NEMO-converter). On the paper machine 1 
(PM1) of Roermond Papier, the flour slurry was processed on the size 
press. 
In particular, a practical production run of the quality Testliner 3 
(RP-Maasliner) in 140 g was carried out. 
Machine conditions: standard, i.e.: 
composition of raw material according to formulation (recycled material); 
2-layer embodiment; 
in-line treatment on size press; 
weight increase though size press treatment: about 3%; 
rate PM: 625 m/min; 
final moisture content paper: 7%. 
During this paper production, the size press solution of native wheat 
starch (thermochemical conversion with ammonium persulfate (APS)) was 
replaced during the run by flour (IJsvogel; conversion: starch 
thermochemically with APS and protein part enzymatically by means of 
Neutrase). 
Processing: good. Result comparable with 100% starch. 
Paper properties: the paper properties are equal to/comparable with starch. 
Depositions and foam formation resulting from gluten were not observed in 
the system. 
TABLE 5 
______________________________________ 
Practical test Maasliner (T.L.3), RP-PM1 
Paper properties Starch (standard) 
Flour 
______________________________________ 
Gram weight g/m.sup.2 
140.1 139.9 
Final moist. cont. 
% 7.1 7.0 
Take-up % 3.2 3.1 
(size press) 
Burst pressure 
kPa 340 335 
Burst factor kPa 243 239 
Breaking 1. 
m.d. m 6,610 6,640 
Stretch m.d. % 1.90 1.90 
R.C.T. t.d. kN/m 1.23 1.18 
S.C.T. m.d. kN/m 4.53 4.65 
S.C.T. t.d. kN/m 2.30 2.49 
Stiffness m.d. kN/m 960 940 
______________________________________ 
TABLE 6 
______________________________________ 
properties stated 
Paper property Unit Standard 
______________________________________ 
1. Gram weight g/m.sup.2 
ISO 536 
2. Moisture content % ISO 287 
3. Burst pressure kPa ISO 2758 
##STR1## kPa ISO 2758 
10. S.C.T. kN/m DIN 54518 
11. R.C.T. kN/m DIN 53134 
12. C.M.T.-30 N ISO 7263 
13. Porosity ml/min ISO 5636/3 
(acc. to Bendtsen) 
8. Stiffness kN/m ISO 1924/2 
5. Tensile strength kN/m ISO 1924/2 
9. Tearing strength mN ISO 1974 
14. Ply-bond J/m.sup.2 
Tappi UM 403 
(Scott-Bond) 
7. Stretch % ISO 1924/2 
6. Breaking length km ISO 1924/2 
______________________________________ 
Note: 
the determinations according to 5, 6, 7, 8, 9, 10, 11 and 12 can be 
performed in the fiber direction of the paper = machine direction (m.d.) 
or longitudinal direction (l.d.), or in the transverse direction (t.d.). 
EXAMPLE 6 
Example 5 was repeated, the flour slurry with citric acid being suspended. 
The results were comparable with those in Example 5.