DE2110599A1 - Process for the production of a continuous fiber web from an inorganic fiber suspension - Google Patents

Description

DipJ.-lng. C-H. Huss

Garmisch-Partenkirchen Sch 346 - He.

Rathausstrasse 14 Garmiseh-Partenk., 15th FeIJr. I971

Hs / Ht-Ü,

Glaswerk Schuller GmbH., Wertheim / Main, fiber path

Method of making an endless fiber faucet from an inorganic fiber coating

It is known to produce flat fiber structures according to the so-called wet process commonly used in papermaking to manufacture. You will do this with fibers, if necessary together with a binder, suspended in water to form a fiber suspension. This is a totally Uniform water-fiber suspension is decisive and therefore necessary for the quality of the fiber structure to be produced that the fiber raw material dissolves into individual fibers in the water. You then get fiber suspension on a rotating sieve on which they are evenly distributed should be knocked down. Ser so educated

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Layer is then withdrawn from the moisture, so that one coherent matted fiber web is created.

Recently, efforts have been made to keep this hot pulp and other natural fibers also use proven wet processes to be introduced in fiberglass technology · As a well-known fiber raw material, fiber bundles from * u stacks of chopped fiberglass strands or fiberglass β rovings are used. In this case, however, the complete opening of the fiber bundles into individual fibers creates great difficulties.

In the manufacture of fiberglass, it is known that a multitude of elenent threads of infinite length without twisting are used and therefore united in a largely parallel order to form a strand. To give the individual threads untwisted in the strand a cohesion and the abrasion resistance in the later To ensure processing, the threads are glued together during production using a binding bag. The threads go at the same time such an intimate connection with one another that it is difficult to hack them into stacks of the same length later on let the original single fibers break down.

Nan tried to reduce the amount of binder to a minimum in order to achieve a better dissolution of the bundles into individual fibers in water, but during the chopping process, in addition to a high level of dust, premature splitting occurred.

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that in no way favors dissolution, but rather only leads to the fact that the pasers become matted before they are added to the water and then all the more heavily or cannot be disentangled at all.

As a result of the insufficient dissolution in individual fibers of the fiberglass stacks mentioned at the beginning, so-called specks often occur in the web, which impair the even distribution of fibers To reduce this formation of specks to a large extent, nan has hitherto managed to take a number of precautions. Once you have the stack length set by ticking as possible kept low (e.g. max 6 am) and to the complex processing of the fiber suspension with the help of additional units accepted for the removal of the defex from the dissolving, storage and working chests. At the same time they tried a better one To dissolve still dp by adding appropriate additives, such as wetting agents, to the preparation and / or the Processing and dissolving times have been considerably extended.

In addition to the costs for these additives, there is also an extension of the processing and dissolving times for the same Machine capacity a significantly larger design of dissolving, Storage and working chutes, which increase costs for the system, the building and finally the production itself affects.

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_{In addition, the known show formation t} caused by the addition of τοη additives, such as the wetting agent, results in "clouds ¹¹ " appearing in the finished web. The quality of the webs is particularly adversely affected when they are very thin Fleece bits with a basis weight of, for example, 45-55 g / a ² are involved.

Such an inhomogeneity does not have due to the preferably used short stack length of e.g. 6 m only in terms of strength, but also visually negative effects. If such glass fiber fleece bits with uneven fiber distribution are used, e.g. as so-called surface fleece in the plastics industry, for insulation and decorative panels or as so-called painter's fleece, it cannot be avoided that on the uneven places bit of unequal porosity too an uneven coating or color absorption follows, which gives the later finished product an annoyingly spotty appearance.

Raising the use of stacks of chopped glass silk or glass silk bovings has also been tried, so-called. Fiber ribbons, which are often also referred to as slivers or goal yarns, are chopped into sections as fiber raw material use. It was believed that sections of this staple glass fiber tape, the staple fibers of which were not glued to one another by any binding agent, would loosen up as a result of the loosening and loose fiber structures in water would dissolve into individual fibers better than fiber bundles made from glass silk.

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However, it has been shown that the deficiencies described above, which are already in use of stacks of chopped glass fiber with a low proportion of binder occur, especially here in increased proportions. This already starts with the hacking process, because as a result of the different «:. long staple fibers of the fiber tape The fiber bundles produced from them do not contain fibers of the same length · In addition, there are fibers the fibers in the ribbon are not parallel and are already tangling very strong during the chopping or cutting process, often in addition to those already during the manufacture of the sliver resulting intimately matted connection of the individual fibers, so that an optional separation of the bundles in individual grains in water is no longer possible. she The result is a strong formation of flakes, which are visually disruptive as clouds in the finished web and to intolerable fluctuations in weight per unit area, strength, porosity and the resulting defects to lead.

The invention was therefore based on the object of finding a way that would be optimal with little effort The dissolution of Crlas fiber structures in single fibers is guaranteed, resulting in an end product with the greatest possible evenness the fiber distribution.

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In principle, this object is achieved in such a way that the individual threads of the fiber structure already have their . Manufacture to be moistened and up to «introduction into the The suspension is kept moist

You selection of the agent used for moistening from among the known liquids used in the manufacture of thread ropes, e.g. Sizing or lubricants, depends on the type of heavy liquid, mostly Yasser, in which case water or a liquid soluble in water is preferably also used for moistening.

Accordingly, the invention relates to a method for producing flat fiber structures from fiber suspensions by allowing the fibers to settle on a moving, permeable surface, e.g. an endless sieve or belt, in which for the fiber suspension from a multitude of finest threads drawn out streams of glass filament or fiber strands and from these individual fiber structures are produced by chopping, which is' characterized by the fact that using for fiber suspension of liquid jets on a winding drum known per se Endless glass threads wound up in a parallel arrangement are peeled off in the form of strands after a certain layer thickness has been reached and on pre-determined tangen chopped in a damp state can be used as parallel single structures.

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The fact that the fibers get into the heavy liquid in a moist state enables such a single fiber structure . practically completely aaf solve what dmreh the ear> allelity of the Fibers within the joint is still supported.

The dissolution of the fibers can be further improved if the wetting agents known for fiber suspension are used via the circuit water of the! Eromel spray, already at the fiber generation directly applies to the fibers · In such a case, the later dissolving of the fiber bundles into individual fibers, even if the fiber length undergoes drying has made world-wide easier

The procedure for realizing the invention Is shown schematically in its individual sections in the drawing.

It can proceed in such a way that, in a conventional manner, a multiplicity of parallel single fibers 1 from streams of liquid are contained in a tub 2 provided with nozzles at the bottom The glass can be pulled out, brought up to a rapidly rotating Sromel 3 and wound around the circumference of the Tronrael.

Un an intensive moistening of all single grains achieve, according to the invention, the xromel surface is on

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sprayed their entire length with a stream of water, for example with a water fan 4, thereby simultaneously good adhesion of the first fiber layer on the drum surface is also achieved.

The intensive moistening of the individual lurks brings about their mutual cohesion while maintaining their parallelism when, after a certain layer thickness has been reached, the drum is completely etched and the hole in the drum is cut in the longitudinal direction b of the drum and peeled off from the drum surface. The layer can also be divided into the drum circumference 6 in order to obtain smaller packages / the moist fiber structure.

In practical testing a durchöchnitt-JLcher moisture content of the Faeermenge at removal ^ of the drum of about 17 was measured fi, is depending on the elapsed time between the manufacturing and Hoes time dream to about 12 - 1i? # reduced.

An excessive drop in moisture content one can at every J? 'all through entuprijofifmde Mautmuhmen

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confront during storage.

However, it is particularly advantageous to immediately bring the still moist packages into a chopping device 8, where they are chopped into fiber structures 9 of preferably between 10 and 30 mm in length.

Here, eich shows another advantage of the use moistened oil-laser fibers in the method according to the invention. It consists in the brittleness that the glass fibers show in the dry state and that e.g. during transport and leads to breaking and matting when chopping, as well as avoiding the annoying development of dust for the operator .

The still moist, parallel single fiber structures 9 become then continuously, e.g. by a conveyor belt 10, preferably with the interposition of a metering device introduced into a mixing vat 11 at regular intervals and mixed with the suspension medium 12, usually water.

The fact that that which causes the cohesion of the fibers in the fiber structure and that which serves as a suspension medium Medium are the same, contributes to quick and complete

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Dissolution of the cohesion of the fibers among themselves. This results in a very intensive breakdown of the fibers guaranteed, so that the suspension, also referred to as "substance", from the mixing vat 11 is supplied by a pump 15 into the working bucket 16 and from there through a pump 17, possibly with the interposition of a final stipper 14 of known design, in the line 22 of the circulating water, and conveyed through this strongly diluted into the headbox 18 can be.

The suspension medium arrives from the Entwasserungskaamer 19 more usual via a line 20 after passing Filter devices in a storage basin 21, from which the circulating water by means of a pump 23 and that via a line 24 water supplied to the mixing vat is removed again.

It is therefore possible according to the invention, also with the known as particularly difficult to suspend glass fibers a continuous cycle of the suspension means 12 from the Mixing vat 11 over the working vat 16 and the headbox 1ö back to üischbütte 11 to achieve what you have been against so far had to work with several mixing and storage chests in such a way that alternating a torrats chute as a work chute was connected to the headbox while the other filled with the swelling of fibers coming from the mixing vat,

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During the time when the work session was empty, With the help of agitators or similar devices, the best possible record was made Prepare paeer vessels that have been pretreated in the Miechbütte strived for, but did not achieve the thoroughness which allows the application of the method according to the invention to be achieved.

Claims (2)

Patent claims Qy Process for the production of flat fiber structures from fiber suspensions by settling of the fibers a moving, permeable surface, e.g. an endless sieve or belt, in which the fiber suspension consists of a A multitude of the finest threads of drawn out fflas streams of thread or Fiber strands and made from these individual fiber structures by chopping "earth, characterized in that that for fiber suspension with the help of liquid jets endless glass thread wound up in a parallel arrangement on a winding drum known per se Reaching a certain layer thickness in the form of strands peeled off and chopped to predetermined lengths in the moist State can be used as a parallel single bevel structure » 2. The method according to claim 1, characterized in that the suspending agent in a continuous Circulation from the headbox via a dewatering chamber fed to a mixing vat, there mixed with the chopped, moist parallel single fiber structures, in a Work bucket and won there via a deflaker into the Headbox is guided. 209841/08 94