DE1031117B - Stiffened paper - Google Patents

Description

The invention relates to a method to stiffen fiber material, such as paper, and water and refractory and the products obtained. The stiffened paper can, for example, on can be used in the field of container and cardboard technology, and the products can be either impregnated fiberboard, corrugated cardboard or corrugated paper to be used as part of the cardboard any common fiber material such as natural wood pulp, sisal hemp, straw Od. The like. Or secondary pulp for chipboard, newsprint or the like. Or mixtures of these Pulps or containers, container elements, pipes and other things made from such materials be.

There are considerable difficulties in engineering To stiffen paper by impregnating it with various substances. To this end, though Nowadays many different substances are used, but they are all made of one or the other Basically unsatisfactory. For many years, sulfur was used for impregnation, although it is the paper strengthens and makes it water-resistant, but because of the high degree of flammability of the all in all, paper impregnated with it is not used with pleasure. It is also treated with sulfur Paper is very brittle and has a corrosive effect on certain metals that come into contact with it a. Another common waterproofing agent is molten paraffin or other wax; it but is only sufficient for waterproofing purposes as there is very little additional strength, and is also flammable. There are also various synthetic resins for impregnation used, but even the cheapest of these substances is still far too expensive for commercial use for example in the field of consumption containers. Various thermoplastics are also available used, but more as a coating than as an impregnation; they require a very high weight ratio of plastic to paper, and the resulting, Of course, a very expensive product must be considered a paper-backed plastic rather than an impregnated one Paper.

The aim of the present invention is to provide an economical method of converting paper sheets or containers made of paper increased rigidity, greater hardness, greater compressive strength and to give greater tear resistance and at the same time to make them more water and fire resistant. After present invention this is achieved in that paper in an impregnation bath of water and Ammonium or potassium alum of a certain temperature and concentration is immersed.

Stiffened paper

Applicant:

Immanuel Lichtenstein

and Abraham Goldstein,

New York, N.Y. (V. St. A.)

Representative: Dr. phil. G. Henkel, patent attorney,
Berlin-Schmargendorf, Auguste-Viktoria-Str. 63

Immanuel Lichtenstein, New York, NY (V. St. A.),
has been named as the inventor

The impregnation of cardboard, paper or press chips with a highly aqueous alum of the very highest 15% of the total weight of the mass to be impregnated is known per se, but it is lacking the products obtained in this way at the desired rigidity and strength. It has however, found to be particularly good quality in this regard by using molten Alum can be obtained if its content in the end product is at least 33V3%, as follows will be described in more detail.

Ammonium alum, Al ₂ (SO ₄ ) ₃ (NH ₄ ) ₂ SO,

24H ₂ O, melts at 93.5 ° C and possesses

in the undiluted, molten state a spec. " Weight of around 1,550.

Potash alum, Al ₂ (SO ₄ ) ₈ · K ₂ SO ₄ · 24 H ₂ O, melts at 92 ° C and has a spec. Weight of around 1.70.

According to the invention, the best results within certain, preferred ranges of spec. Weight and temperature reached. Preferably the ammonium or potassium alum is melted and the Melt so much water added that the spec. Weight between 1.452 to 1.455 in the case of ammonium alum and between 1.440 and 1.505 in the case of potash alum. Without the addition of water, the melted alum a thick and fairly syrupy consistency. By adding water in the above However, a viscosity is created to an extent that almost corresponds to that of pure water. Perhaps the mixture forms a higher hydrate of alum than the formula above indicates, and this assumption is supported by the fact that the for

809 528/390

Setting of a certain spec. Weight actually required amount of water deviates from the calculated one. In fact, however, there was no literature reference found about such a higher hydrate, and hence it is referred to herein as a mixture.

In order to achieve the best results, the alum-water mixture should be within the above-mentioned, preferred areas of the spec. Weight at a temperature of 108 to 109 ° C in the case of ammo

It is impossible to keep the temperature in the case of ammonium alum above about 109 ° C and in the case of pressure Potassium alum should be increased above about 104 ° C, as the mixture "boils" and at this temperature it evaporates steams or decomposes, although this limit temperature naturally has something to do with the spec. Weight fluctuates. The term "best results" used here takes into account the level of impregnation that required to achieve complete impregnation

nium alum and from 103 to 104 ° C in the case of potash 10 borrowed time and also the development of the highest festival alum held and the fiber body to be treated speed. For example, it is within the preferred therein be immersed so long that the mixture th range of temperature and spec. Weight on all sides can penetrate. Within the pre- lent, largely and evenly in about 30 seconds preferred ranges of spec. the gaps in the one below as special Weight and temperature will fill the penetration 15 example of the material described. That either The paper and cardboard products listed above have the products specified in the example, usually achieved in 30 seconds and less, exhibits excellent strength properties. the and to achieve satisfactory results from- Impregnation can be carried out with simultaneous reduction Ranging degrees of penetration will be shortened in 10 to the final strength when 30 seconds reached. Since water is constantly required in the bath, lower strength is required. A work temperature evaporates, it must constantly and in short outside the preferred ranges can generate time intervals be refilled to the spec. Deliver a benefit that is either incompletely saturated weight within the above, preferred range to or not so firmly with complete saturation keep. like the best example is. Such products can

Although the preferred 25 given above are completely sufficient or for certain application areas of the spec. Weight the best results may even be preferable for purposes of
experience has shown that they can deliver good results while within the preferred range of the

also with a slightly higher spec. Weight within the spec. Weight the preferred temperature just range from about 1.455 to 1.485 for ammonium is below the "boiling point" of the mixture, results in alum and from about 1.505 to 1.535 for potassium alum, notably at higher spec. Weights can be achieved in particular when the best temperatures are used outside of the preferred range. Comparative impregnation at lower temperatures,
wise meager results are obtained when one The present invention offers both

the spec. Weight far above 1.485 or 1.535, both from the point of view of the product and from the point of view of the product, because the associated viscosity advantages over paper impregnation make it difficult to obtain sufficient sulfur. According to the present invention, paper and the urgency can be ensured. If you have the spec. Weight of the paper products listed above by an Im less than 1.452 for ammonium alum or 1.440 for potash impregnation at only a few degrees above the alum, the results will be fluctuating, boiling point of the water temperatures because the alum is increasing the slope 40 and within only 30 Seconds or even less shows not to harden in places. You can even be largely solidified and stiffened, while the spec. The weight of ammonium alum falls below about < _{y as the} widespread sulfur impregnation process 1.440 and of potassium alum below 1.420, so at considerably higher temperatures and with much higher temperatures, the mixture no longer hardens when it cools down - longer impregnation times for the paper to give the paper the desired strength must be performed.

to give. In a corresponding manner, although the preferred temperature ranges for ammonium alum are between 108 and 109 ° C and for potassium alum between 103 and 104 ° C, still satisfactory results with ammonium alum in a temperature range of 106 to 108 ° C, if the spec. Weight is in the preferred range of 1.452 to 1.455, and can be achieved with potassium alum in a temperature range of about 102 to about 104 ° C if the spec. Weight is in the preferred range of 1.440 to 1.505. Potash alum at temperatures lying give even below about 106 ⁰ C at 102 ° C or ammonium alum relatively poor results, particularly with respect to the

As specific examples of the preferred process and to illustrate the desirable product properties the following is presented:

- ₀ - Example

A sheet of multi-layered kraft corrugated cardboard about 10 mm thick, consisting of three layers of 0.23 mm strong corrugated cardboard with A and B grooves (type A: 11.8 grooves per 100 mm, each groove 4.2 mm high, Type B: 16.7 grooves per 100 mm, each groove 2.46 mm high) with 0.41 mm thick intermediate layers Immersed for 30 seconds in a bath of ammonium alum and water, as close as possible to one spec. Weight within the range of 1.452 to

Extent of penetration. Only in the case of Ammo-60 1.455 and at a temperature between 108 and

aluminum alum in excess of the preferred range spec. Weight up to about 1.485 has shown to be better penetration at lower temperatures achieved. For example, a somewhat satisfactory penetration can be achieved a spec. Reach a weight of 1.485 and a temperature of around 104 ° C. In the case of the potash alum It is noteworthy that the slightly soaked products obtained at a temperature below 102 ° C

109 ° C was maintained. Were for the investigation cut off test strips 50 mm wide and 300 mm long from this sheet.

The test strips prepared according to the previous example were, with the B-groove facing up and only supported near the end by horizontal, 250 mm apart, cylindrical supports, subjected to uniform and local loads. the Strips carried an evenly distributed load of shot

have increased strength. At atmospheric 70 of 4.5 kg and an additional one on three points of the

5 6

Strips evenly distributed, local load of 15.9 kg, dripping of the product can be the percentage

d. H. a total load of 20.4 kg. Similar sample capacity in the case of ammonium alum

strips of non-impregnated cardboard equal up to 210% and in the case of potash alum up to 190%

baus failed even with a steady increase in shot; however, this depends on the economic standing load weighing just 2.7 kg. From a 5 point point of view, this is not the best measure

". · Considered TT.

¹ In the general sense of the application of the invention

A sheet of kraft cardboard as described in Example I on products of various types was fixed for 30 seconds in a bath that was immersed under potassium alum and water when the measures were carried out, the most preferred conditions for spec. Weight and close on a spec. Weight within the temperature range, the product has reached a percentage increase of 1.440 to 1.505 and a temperature tolerance of at least about 50% 103 and 104 ° C. The sheet will. If outside of the preferred ranges, but then taken out of the bath and off - still working within the limits, left to cool. In the manner indicated in Example I, sample products were obtained, experience has shown that the prostripe tends to be cut off and examined. As a result of the impregnation, it was found that the strips had an even shot load - from being quite high. If for example 4.5 kg in addition a i _m the case of ammonium alum kg, the measures for equally distributed load of 14.5 to three points of the strip, ie a total 20 comparatively high specific gravity. Weights between 1.455 load of 19 kg, carried. The specified lower value and 1.485 and comparatively lower temperature in the compressive strength. In terms of tensile strength, as stated above as permissible, the sample has not yet been carried out at the highest apparatus, the percentage possible load fluctuates from 36.3 kg. Similar probing capacity between 210 and 400%. strips of non-impregnated cardboard same up 25 I _n a similar manner, it varies in the case of Kalibaus failed at a uniform compressive load alum 190-400% when the measures kg of only 2.7. at spec. Weights between 1.505 and 1.535 by-The proportion of impregnating agent in the produce-to be carried. Under these conditions, nits according to the examples, expressed in weight - probably a large part of the alum in the form of percentages of impregnating agent to non-impregnating is wasted disproportionate and in Example II about 140%. This figure was calculated to be a modest contributor to the ultimate strength, adding the weight of the unimpregnated to the product.

Paper from the weight of the impregnated paper - according to the invention with ammonium or potassium alum drawn and the difference due to the weight of the 35 impregnated paper can not be in the absence of one impregnated paper was divided. The other's fuel did not ignite For the sake of simplicity, this number will be taken as the percentage, which gives it a great advantage Called absorption capacity. compared to the previously used, easily flammable, In order to achieve the greatest strength in the product without alum sulfur-impregnated paper. Burning, wasted sulfur Paper impregnated in the form of a superfluous coating 40 gives up large amounts of sulfur to achieve the surface and the paper fibers, dioxyd, which is not toxic, but very irritating was found to be particularly beneficial, works within and makes fire fighting more difficult. At Zerder above-mentioned preferred ranges of spec. disruption of such paper in an incinerator Weight and temperature to work. Within these, the sulfur dioxide also affects the atmosphere Areas can reach rapid soaking 45 harmful in the neighborhood. That according to the invention and the impregnated product runs so well. Impregnated paper, on the other hand, burns itself against that a completely impregnated product without the use of another fuel, not with an active one excessive surface coating remains. Open flame, and even in hot flame and in mutual can the percentage absorption of other fuel only glows and carbonizes it one within the preferred ranges of spec. 30 and is consumed. That means the highest grade Weight and temperature treated product due to fire resistance: The material offers no fire modification the impregnation time up to the dangerous and can still be in an incinerator The complete, all-round impregnation of the er-be destroyed, thereby the problem of the end product required period of time is modified valid elimination is solved.

the. For papers with the in the exemplary embodiments 55 The alum-impregnated paper according to the invention specified weights and properties are not hygroscopic and fairly water resistant, for complete impregnation approximately 30 Se- For certain purposes it can be known per se announce or below required. In such a way by spraying on paraffin or other Trap results in immersion of considerably under wax after alum impregnation A less complete 60 seconds will make the duration less complete. In particular, experience imbibition is achieved and a proportionately lower one according to the immersion of the impregnated generation percentage Absorbency. However, you can achieve nisses in a mixture of 50% paraffin and 50% excellent water resistance with the amount of montan wax added to the product, Impregnation agent the most favorable strength - whereby the fire resistance of the alum impregnated improvement. A useful increase in strength of the paper is largely retained. If so desired one achieves with the products which in the two measures can be combined in this way can be used by shortening it in such a way that the wax melts on the upper part Impregnation time that allows the alum-water bath to float within 30 seconds, so indicate a percentage holding capacity between each sheet or container of paper at about 50 to 150% is achieved. If the impregnation bath is insufficiently left a coating

absorbs from the selected wax or wax mixture.

If so desired, the paper can be given a Greater surface hardness can be given that the alum-water mixture described above neutral substances are added. Such increased surface hardness is particularly common in paper containers desirable, which are secured by steel straps, since the containers thereby counteract the cutting effect the steel belts become more resistant. Kaolin is preferred as a suitable material for this, however Fresh or used fuller's earth and nepheline syenite also give good results. The neutral fabric is preferably used in amounts equal to 1CH / o by weight of alum used, but good results are also obtained with additions of 5 to 25 percent by weight. In addition to increasing the surface hardness, the addition of such neutral substances to the impregnation bath gives the paper an even, opaque tint and thus a pleasant appearance.

The paper treatment according to the invention takes place in sheet form for building and construction purposes or on finished containers for storage and transport purposes. If desired, the paper can also be in Impregnated arc shape and shaped into containers before cooling. You can also use a fluted Impregnate paper and corrugate it while it is still hot, or impregnate it while it is soft Allow to cool, rewind for storage and / or transport and before assembly corrugate into corrugated cardboard with the help of the usual, heated corrugated rollers. In the latter case, the intermediate cardboard untreated or treated in a suitable manner or, if desired, impregnated according to the invention be.

The process of the invention can be economical to produce a very strong bonded paper be used, which is highly fire-resistant and, moreover, no harmful effects of corrosion exerts on common metal. Even in the case of pure copper, it only causes a slight surface blackening, and this is done to a far lesser extent than by sulfur impregnated paper or, for that matter, ordinary paper impregnated kraft paper.

Claims (4)

PATENT CLAIMS: 1. Stiffened alum-impregnated paper made from cellulose fibers, characterized in that the alum content is at least 33V3 ° / o. 2. A method for producing stiffened paper according to claim 1, characterized in that that the fiber material is immersed in a bath of water and ammonium or potassium alum, which when using ammonium alum on a spec. Weight in the range between 1.452 and 1.485 is set and kept at a temperature in the range between 104 to 109 ° C and that when using potash alum on a spec. Weight set in the range between 1.440 and 1.535 and maintained at a temperature in the range between 102 to about 104 ° C. 3. The method according to claim 2, characterized in that the alum solution finely divided, neutral Filler is added in an amount between about 5 to 25% by weight of alum. 4. The method according to claim 2 and 3, characterized in that the surface of the alum-water bath is covered with a floating layer of molten wax and the paper after impregnation through the Layer of molten wax is passed through. Considered publications:
German Patent Nos. 28 139, 80 998, 732, 599 402; Swiss patent specification 134112;
British Patent 690,434. © 809 828/390 5.58