Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/21—Macromolecular organic compounds of natural origin; Derivatives thereof
  • D21H17/24—Polysaccharides
  • D21H17/28—Starch
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
  • B29C43/22—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of indefinite length
  • B29C43/224—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of indefinite length having a profiled section, e.g. tubes, rods
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/08—Melt spinning methods

Definitions

• the use of a cold swelling starch has the advantage of avoiding the heat treatment necessary when a substance such as potato starch is used which is then liable to coagulate.
• the paper obtained by the process according to the invention has special and unexpected properties as compared with the paper manufactured by known processes.
• the paper formed by the new process has a much greater resilience, especially as to tearing, folding and perforation than paper manufactured from a similar pulp but sized in the ordinary manner.
• the paper manufactured according'to the present invention also has under the same conditions a far greater impermeability.
• the amount of increase of resistance of the paper to tearing, -folding-and perforation and the amount of increase of' its impermeability will depend on the quantity of cold swelling starch present in the paper manufactured.
• the incorporation in the paper of a cold swelling starch may be made in any desired manner.
• the cold swelling starch may be added in the dry state to the primary materials at the time of the preparation of the pulp and at any stage of this preparation. For example, it may be introduced in a dry state:
• a solution is prepared in water of In the latter case the papera cold swelling starch and this solution is incorporated either in the primary materials at the preparation'of the pulp, at the comminution of their treatment or at any phase of the latter, or
• the cold swelling starch is incorporated as a solution in the paper at any other stage of its manufacture.
• this solution can be incorporated in the paper sheet itself.
• the solution could be spread on the sheet by the. couching cylinders or at the commencement or at any other part of the drying process or by the immersion or dipping of ,the sheet in a bath of a cold swelling starch or by any other means.
• papers having the new valuable properties can be obtained by adding to the paper pulp in the rag engine, a quantity of cold swelling starch comprising between 0% and 5% of the weight of the paper obtained. A higher percentage may be utilized for special papers.
• Cold swelling starch has an 150- The starch is retained far better by the electric point causing it to be particularly well retained by the fibers when the pH is changed by the addition of aluminum sulfate (alum) in ordinary ways of making paper. Paper made in the new'way, it is found. has m- 2 I better mechanical properties with respect to folding, Mullen and breaking strength. In addition,
• cold swelling starch also has a favor- Results in first paper mill I Beating Beating Beafl'n Beating time 7 time 6% time time 7 hours hours hm titty it W o o 0 322.23 corncold lad starch swelling swelling arc starch 32% 32 32% 32+ 006 0. 0065 0. 0065 0. 0065 30 35 38 39 so 78 84 se Tear (cross direction) 73 70 78 79 Fold Emachine direction)- 74 77 100 112 Fold cross direction)..- 26 92 94 Density 23B 242" 3'16" 3' 25' Ink 7'l" 652" 8-27 8-52' Our].
• a further improvement caused by the use of a'cold swelling starch is the following.
• the majority of the disadvantages connected ⁇ .ith fastrunning paper making machines are located between the wet-calendar and the first drying cylinder. At this stage the paper is often too weak to withstand the speed of the machine. strength of the wet paperis influenced very favorably by the addition of cold swelling starch and due to this and also to the quicker-drying the speed of paper machines may be considerably increased. This increase in speed'of paper machines has in some instances amounted to 20%.
• the pH value is reduced to about pH 5 or pH 4.5, preferably by adding alum. This is necessary in order to obtain with this product the'greatest possible effect and also in order to fix the cold swelling starch in the-paper pulp.
• the incorporation of the cold swelling starch into the paper pulp is preferably effected at an early stage in the beater, at which stage the water does not as yet show an acid reaction, but is neutralor onlyslightly alkaline and after the I cold swelling starch is dissolved, then the pH is lowered to about 4.5 by the addition of alum.
• the properties 01 the cold swelling starch may be improved by adding before, during or after its manufacture, various chemicalswhich have an influence on the properties of the cold swelling starch, e. g. aluminium compounds such as alum, aluminium sulphate or alkali aluminates, feebly alkaline salts of sodium and potassium, such as borax or sodium phosphates, albuminous substances, etc.
• various chemicals which have an influence on the properties of the cold swelling starch, e. g. aluminium compounds such as alum, aluminium sulphate or alkali aluminates, feebly alkaline salts of sodium and potassium, such as borax or sodium phosphates, albuminous substances, etc.
• the starch would dissolve and owing to the high dispersity oithe solution it would not be satisfactorily retained bythe fibers.
• the percentage of starch retained in the paper when a cold swelling starch is used is far above the percentage retained when ordinary starches are used. When ordinary starches are used the The.
• starch products are used in a new and special form in which they have a quite distinct and better influence upon the paper than the ordinary starch products. heretofore used.
• ordinary starch to the pulp in the manufacture of paper has a favorable influence upon the properties of the paper.
• Such starch is mostly used in the form of ordinary starch which is boiled with water or 'heated until-it is swollen.
• the starch may be used inthe form of a thin boiling starch, or a chemically treated starch, or a soluble starch, oran attrition starch, or a converted starch, etc.
• a thin boiling starch, a chemically treated starch, a soluble starch, an attrition starch or a converted starch are insoluble in cold water but such starches are soluble in hot water.
• converted starch above such starch products as are obtained by stirring the starch with water and strong alkalies such as caustic soda or sodium silicate.
• the starches are converted into alkali starches which can form solutions which also have a higher dispersity than the pastes obtained by boiling raw starches. Solutions so obtained correspond with those of the chemically treated, thin boiling or soluble starches with the prising inasmuch as other forms'of starch have for a long time been used in the manufacture of paper.
• cold swelling starches it must be understood that such starch products are meant which when mixed with a quantity of cold waterof many times their weight, say 10 to 15 times the weight of the starch, will form a thick cohering mass and with greater amounts of water will form a good and tolerablyperma- 'nent dispersion.
• Starch granules comprise two different starch modifications, namely, the amylose which is present in the interior of the starch granules, and the amylopectin which forms the outer layer and which forms the characteristic structure by which starches of different origin may be distinguished under the microscope.
• amylopectin is the substance from which the starch paste derives its viscous properties.
• the granules of starch will absorb water and grow larger and larger.
• the absorption of water by the granules is so large that the granules may be considered as watery aggregates of the original starch granules.
• the above does not apply to the case where an exceedingly great excess of water is used.
• the swelling power of the starch granules will cause'a crowding whereby the soft swollen aggregates are pressed together and due to such pressing together they will stick together and will form a mass known as a paste which has a sticky characteristic.
• the outside layers of the starch granules constituting the amylopectin are composed disregarding their chemical constitution of layers which tend to counteract the swelling and which still remain after the swelling.
• a boiled starch paste therefore is composed more or less, dependent upon the strength of the boiling process, of partly damaged swollenv portions of the amylopectin shells or layers which support or carry the amylose which has not the ability to swell.
• a boiled starch paste therefore is a starch which has been changed slightly physically but not changed chemically and the structure of the layers or shells isstill apparent therein and may with alkalies or acids, these chains are shortened and the more intensive the hydrolyzing process, the shorter the chainsbecome and therefore their dispersion in a vehicle the greater.
• the colloidal particles of the modified starch in a vehicle are therefore smaller.
• the formation of a soluble or modified starch by' chemical action as by the hydrolyzing process does not cause the structure of the layers of amylopectin to disappear entirely. Even when hydrolyzed to dextrine with the exception of the lower grades oi dextrine, the original physical structure of the starch granules may be recognized.
• the starch In the case of thin boiling, chemically treated, soluble or converted starches, the starch has been subjected to the hydrolyzing process with suitable che micals suchas acids, oxidizing agents, diastase, etc. which render the product more easily soluble in hot water. In this way the starch particles have become smaller and solutions are obtained therefrom with a lower viscosity. In such solutions the aqueous starch aggregates are smaller so that the solution has a higher dispersity. This .is also the case with alkali starches.
• a cold swelling starch is also sharply distinguished from what is known as an attrition starch, such as is obtained by-grinding starch granules in a mill. In such. case the outer skin or layers of the starch granules are ruptured or otherwise mechanically broken. It is possible to separate an attrition starch into a soluble and an insoluble part by treating the same with water.
• cold swelling starch a homogenized paste is formed when mixed with cold water and not 'a product the granules of which swell in cold water to some extent without giving however a uniform mixture from which the swollen granules do not settle out on standing.
• Cold swelling starches useful for the present purposes. and having the properties described may be manufactured in the following manner: raw starch is mixed with a small quantity of cold water; the amount being less than that ordinarily employed in boiling up starch. For example, with a starch ordinarily requiring about 8 In a.
• the cold swelling starch should be so ground and sieved that the particles are substantially .larger than the granules of the original raw starch.
• the granules of raw-starch are so small that they may only be observed microscopically, which is not the case with the granules of cold swelling starch.
• the 'characteristic structure of ordinary granules of raw starch is not found in the new granules.
• the size of the particles of the cold swelling starch should be between a 10 mesh and 80 mesh sieve.
• the product obtained by allowing the cold swelling starch to swell in cold water has other properties than those of the other starches such as soluble, thin boiling, chemically treated, attrition or converted starches. This is equally the case with the solutions obtained from the different products owing to the fact that the particlesof the dried cold swelling starch are larger than 'the. original starch granules.
• a starch paste is dried and then ground, the product obtained will not thereafter swell with use into a paste since the product has become insoluble.
• the raw starch is mixed with very little water, for example only 10 2 parts and it is then suddenly heated to above the boiling point whereby a viscous mass is obtained that is dried at the same moment under mechanical presure by squeezing it out into thin layers which are then ground when dried.
• the product so obtained will swell with cold water into a paste or viscous mass and the jelly obtained from a cold swelling starch is not the same as that which is obtained by the boiling of starch into a paste as set forth above.
• a cold swelling starch due to the process above outlined for making the same differs materially from a modified or soluble starch in that in a cold swelling starch the change is not a chemical destruction or a 'hydrolization since the tributed throughout the paper; said cold swelling starch having been obtained by subjecting 1 part of raw starch mixed with 0.5 to 2 parts by weight of water to heat and pressure whereby said raw starch issimultaneously subjected to heat'above the gelatinization point and to pressure so as to burst the starch granules and forming cold swelling starch granules of substantially larger 'size than the granules of said raw Starch said cold swelling starch being present as an irreversible colloid little affected by moisture and temperature changes, said paper being resilient,
• a process of sizing paper comprising incorporating into the aqueous suspension of fibrousmaterial from which the paper is to be made, up to 5% by weight of a granular cold swelling starch which has been obtained by subjecting. 1 part of raw starch mixed with 0.5 to 2 parts by weight of water to heat and pressure whereby said raw starch is simultaneously subjected to sure so as to burst the starch granules and form'- ing said granular cold swelling starch with granules of substantially larger size than the granules of said raw starch, and then completing the manufacture of said paper whereby said paper is sized with said cold swelling starch, the said paper being resilient, having high folding, Mulion and tearing strengths and being non-picking parts by weight of water to heat and pressure 1 whereby said raw starch is simultaneously subjected to heat above the gelatinizationpoint and to pressure so as to burst the starch granules and forming said granular cold swelling starch with granules of substantially larger size than the
• a process of sizing paper comprising incorporating into the aqueous suspension of fibrous material from which the paper is to be made a
• alum is used to lower the pH value.
• alum is used to lower the pH value.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Paper (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=32031851

Family Applications (1)

Country Status (5)

Cited By (21)

• 0
  • BE BE385571D patent/BE385571A/xx unknown
  • NL NL59613D patent/NL59613B/xx unknown
• 1931
  • 1931-10-08 FR FR739592D patent/FR739592A/fr not_active Expired
  • 1931-12-23 GB GB35586/31A patent/GB380674A/en not_active Expired
• 1936
  • 1936-04-22 US US75887A patent/US2105052A/en not_active Expired - Lifetime

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