NO125091B - - Google Patents

Description

Method and device for the production of

fiberglass bodies.

In a known and in practice widely used method for the production of fiberglass bodies, continuous threads are obtained immediately from strands of liquid or softened glass with the aid of a rapidly rotating draw-off drum. For the completion of a one-time winding on the drum, these threads are pulled off by means of a scraper and are simultaneously divided into staple fibers by means of the same. The fibers thus obtained are then, being suspended in an air stream, fast along guide surfaces and remain on

somewhere at a distance from the extraction drum during the removal of air compressed into a final product in the form of a fiber body, e.g. a flat fibrous body, such as a mat or felt, or a

band-shaped fiber body, such as a fiber cord or fiber string, but also to a shaped body such as e.g. a tiller (German patents no. 825.<4>-56 and 976.682).

Both for the drawing of the threads and for the production of the bodies from the fibers obtained from the threads, the threads or fibers must be coated with a liquid medium. This usually happens on the way from the thread's unwinding point to the place where the thread touches the take-off drum for the first time. For this purpose, a device is mostly used which, in the form of a pad of an absorbent material, is arranged in a suitable place, so that it extends over the width of the run-off thread groups, resp. the width of the take-off drum, and as the parallel pulled threads touch the pad moistened with liquid, possibly under pressure. The pillow can e.g. consist of a cloth wound on a rod and which, due to the consumption of liquid, is continuously supplied with new liquid by means of a drip device. In practice, it is not easy to transfer the liquid from the pad to the high-speed (over 2,900 m/min) withdrawing threads. Of the many proposals for this purpose, the method according to Austrian patent no. 218,191 has above all succeeded.

In most cases, the coating of the pulling threads '

with a liquid, in practice called "lubrication", a triple task.

One task consists in giving the thread an adhesion to the surface of the extraction drum during its rapid rotation and which is great enough to prevent a slip between the thread and the drum surface. Secondly, the coating must make the individual glass strands flexible and

bendable to protect it from breakage or other mechanical damage during processing. Finally, the staple fibers obtained from split glass threads must be given a mutual tensile strength that gives the fibers in the fiberglass body produced by compression of the fibers, e.g. a fiber strand or a felt not yet treated with a binder, a certain cohesion resp. adhesion.

Next to these main purposes for a liquid coating agent

there are also other possibilities, but not related to the lubrication itself, such as e.g. coloring of the fiberglass bodies.

In practice, it is both with regard to the composition and also

with regard to the dosage of the coating agent, e.g. the lubricant,

a problem to satisfy these three requirements to the same extent. In the past, when producing the coating liquid, one was mostly forced to enter into a compromise, i.e. to put together a multi-component liquid whose components best ensured the adhesion of the threads to the drum circumference, spared the drum surface, ensured the scraper's operating characteristics and ensured the mutual adhesion between the fibers obtained from threads in the fiber body, which components also had to be miscible with each other and as much as possible had to work in the correct sequence and also possibly contain color or other coating media.

Also the dosage, of it per coating fluid emitted per unit of time caused considerable difficulties in practice, especially also for the reason that the aforementioned requirement that the components should work at the right time, in practice was not always possible to realize to the full extent.

For this reason, on the one hand, the threads must only be coated with as much coating agent as is necessary to make them suitable for being pulled off from the drum, while on the other hand, the individual staple fibers after leaving the take-off drum must

exhibit sufficient coating agent to ensure their wear resistance and mutual adhesion in the fiber body. An over-

dosing is therefore harmful as the threads then release part of the liquid on their way along the drum circumference during stretching and transport to the scraper, e.g. the lubricant, to the drum surface. The lubricant adhering to the drum surfaces will then soil the drum surface and split due to the constant rubbing between the scraper and the drum, whereby harmful residues are formed on these which prevent the continued removal of threads and the division of these into fibres. These residues also form, together with finely divided thread residues, a kind of "grinding paste" which attacks the surface and makes it unsuitable for continued wire drawing. Thus, one is faced with the problem of either sparing the drum surface by under-dosing, whereby however the fibers to be pressed together into a molded body are supplied with too little liquid so that the mutual adhesion

' deteriorates, or in the event of an overdose to exchange this disadvantage for a constant interruption in production for cleaning the drum surface.

An under- or overdosing, however, also has an adverse effect on the spinning process itself, i.e. the formation of the threads at the spinning cones on heated ends of glass rods or during spinning warts of a melting furnace or chute containing liquid glass, as well as the withdrawal and stretching by of an extraction drum. When the threads on the take-off drum get too little coating, their adhesion to the drum surface becomes insufficient and, as a result of slippage, they are pulled off with different thicknesses. This not only causes cross-sectional variations in the thread, but the threads can also, due to the jerky pulling that occurs during slippage, even wear out, or if they are not pulled off for a moment, in a way "stay put" and thus burn up at the pull-off points. In addition to the soiling of the drum surface and the scraper described above, a coating that is too heavy also has an adverse effect on the spinning process. The threads will then more or less "swim" on the drum surface, which in turn results in a varying thread thickness.

For the production of glass staple fiber strands, a sufficient and evenly distributed proportion of lubricant is above all of the greatest importance, as the yarn uniformity and tensile strength are directly dependent on this. On the other hand, a non-uniform proportion of lubricant will result in a non-uniform firmness, which in further processing of the fiber strand results in a different stretch which in turn leads to a non-uniform fiber yarn.

In the traditional way of supplying the withdrawing threads with a lubricant coating, it was left to the operator who worked at the fiber production device to supply the lubricant device located between the thread withdrawal point and the withdrawal drum with more or less lubricant liquid, whereby oscillations also inevitably arose in the finished fiber strand, which fluctuations could in practice be measured in values from 0.2 to 0.8% lubricant content. It is obvious that the operator therefore primarily aimed to prevent visible soiling of the drum surface in order to ensure unhindered movement of the drum and the wiper. Therefore, even where the production required a larger proportion of lubricant, too small a proportion was rather used, as the operator considered it more important to achieve a longer disturbance-free operation of the extraction device than the fiber bodies produced in connection therewith whose failure at the first moment did not was visible.

Here, it first seemed possible to add the lubricant, which in a way keeps the fibers weakly stuck together as far as the necessary cohesion of the fibers in the fiber body during the further processing of this is concerned, to the fibers in the mold body only after the formation of the same. However, this had the disadvantage that, according to its nature, this method, which only works on the surface, resulted in the fibers that were included in the glass fiber body and that were farthest from the lubricant application device, e.g. a spray device, sufficient lubricant was not supplied with certainty, which was above all evident in the production of a glass staple fiber strand or a pre-yarn. In practice, it has proved impossible with this method to add lubricant to the core of the fiber strand, which naturally has a detrimental effect on the tensile strength of the fiber strand in connection with the stresses during its winding and subsequent processing into yarn.

The method according to the invention avoids these disadvantages and generally involves coating the pulled threads and the fibers obtained from them with separate agents, in particular with substances which are adjusted to the relevant method step. For this purpose, first the threads are, in a manner known per se, at some suitable place between the spin-off point and the thread-de-airing device from the drum surface, and then the fibres, appropriately in the air stream which carries them to the point of compression of the mold body, are individually brought into contact with a suitable liquid coating agent, e.g. lubricant, glue, binder, color and the like. By proceeding in this way, there is no need for the composition or selection of the corresponding coating agent for forming the glass fiber body to take into account the spinning process of the threads, but can adjust these purely to the purpose of application or the processing of the corresponding product. Likewise, the lubricant required for pulling off the threads using the drum can be selected only for this purpose and applied to the threads in precisely dosed quantities.

The invention thus relates to a method for the production of glass fiber bodies, which e.g. mats, filters, strings, bands, shaped bodies etc. where threads, which are produced in an arbitrary manner, are drawn out and off by means of a drum and on the withdrawal from the circumference of the drum are divided into fibers which are suspended in a continuous stream of air, fed along guide surfaces to a surface or into a space to form the fiber body and during removal of the air portion is compressed into a running fiber body, the threads being fed to the drum being coated with a liquid which serves to increase the adhesion, to the drum surface during the withdrawal and also i.a. the mutual tearing strength of the fibers in the fiber body to be formed and as in a further stage separated both in terms of time and position another liquid treatment is carried out. This method is distinguished by the fact that the other liquid treatment

of the individual fibers which are formed by the threads and which are suspended in an air stream and are fed along the guide surface is carried out for the fibers to be compressed to form the fiber body, the fibers being fed individually past transfer elements emitting treatment fluid which project into the fiber path. The invention also relates to suitable devices for carrying out the method.

Since the idea underlying the invention consists in separating the coating of the threads with a liquid medium from the coating of the fibers during the production of glass fiber bodies, and since numerous methods for coating the threads, including others proposed by the inventors, are known, the proposals for devices for carrying out the method according to the invention only with the second method step, namely coating the fibers produced from the threads.

The invention will now be described in more detail with reference to

the accompanying drawings which illustrate a number of devices which are suitable for carrying out the method, and in which: Figure 1 schematically shows in partial section and on a reduced scale a device for producing a laminated glass fiber body, e.g. a felt, a mat or the like according to the invention. Figure 2 shows a side elevation of a device according to the invention for producing a cord- or yarn-like glass fiber body.

Figure 3 is a section along the line III-III in Figure 2.

Figure h- is a section through a detail of the device according to Figures 2 and 3. Figure 5 is a modified embodiment of the device according to Figure 3. Figure 6 is a vertical section through a further variant of a device according to the invention for production of a ribbon-like fiberglass body. Figure 7 is a vertical section through a further embodiment of the exemplary device shown in Figure 6.

Figure 1 shows the part of a plant of interest to the invention for the production of a laminated glass staple fiber body (e.g. according to German patent no. 976,682). The plant consists of a high-speed rotating take-off drum 1 on which a large number (approx. 130 to 500) of arbitrarily produced, parallel threads are placed after they have been, by means of a known smore device d, e.g. a rod, the necessary coating has been applied for the threads to stick to the draw drum. With the lubricant device od, one can also, as illustrated, force several rows of threads f into one thread plane f'. These threads pulled off with the help of the drum are then partly on the surface of the drawing drum, partly with the "rotating wind" or co-rotating boundary air layer produced by the rotation, fast to a scraper 2 which lies tangentially or almost tangentially against the drum surface and which is attached to a about an axis pivotable carrier strip 3-The extraction drum 1 moves in a housing that partially surrounds the drum, called "apron", if at a distance from the drum surface the surrounding wall h holds the circulating wind together. The continuation of the channel formed by the drum surface and the inside of the apron forms, with the scraper 2 as an intermediate link, a turning device generally denoted by 5 with a connected guiding device 6 which guides the fibers to the place where they are formed by compression into a fiber body.

The threads f entrained by the drum 1 when it rotates in the direction of the arrow A and continuously pulled from the thread production device (not shown) are raised by means of the scraper 2 from the drum surface and split into fibers of different lengths, whereby they together with the pulled-off form a winding a fiber air current S which is equal to the width of the drum.

At a suitable location, conveniently at the actual turning part, possibly also in the horizontally extending cover wall 6 serving as a guide device, a coating roller 7 rotates in the direction of the arrow B. It can, for example, rotate in an immersion bath containing

the liquid medium, or as illustrated, is continuously supplied with a film of the liquid coating agent by means of a dripping or spraying device 8. The coating roller 7, whose axis 9 is stored outside the turning part 5? protrudes with part 10 of its circumference into the turning device 5? i.e. that it interrupts the guide surface formed by the turning device and the cover wall which guides the reversed fiber stream F, so that the individual fibers are forced past the projecting surface of the turning device by the coating roller, whereby they are applied to the coating medium.

Thereby, it is achieved that the individual fibers on their way from the place of manufacture to the place of compression into a fiber body entirely or for a significant part come into contact with the current necessary amount of liquid medium, so that all or nearly all the fibers in the manufactured product is moistened with the desired amount of liquid medium and that the degree of wetting does not depend either on their location in the manufactured fiber body or on the intensity of the coating on the threads manufactured as a preliminary product.

Even with thin fiberglass filters, such as used as carrier material for the production of bitumen-containing glass felt roofing paper, corrosion protection bandages for rudders and containers, etc. , when using traditional methods, for reasons as mentioned above, it is difficult to evenly distribute a liquid treatment agent, even over a cross-section which only constitutes fractions of a millimetre. It is even more difficult, as will be known from practice, using the traditional methods, e.g. when lubricating threads or using a spray device after the production of a ribbon-like fiber body, to introduce a liquid, e.g. an adhesive liquid, evenly into the core of the fiberglass tape, a warp or strand. Only with the method according to the invention, whereby the individual fibers are brought into contact with the liquid after their production, has it been possible to produce a band-shaped fiber body which throughout its cross-section can exhibit a uniform and sufficient proportion of the pre-filed treatment liquid. Experiments have shown that the cohesion of the fibers in the fiber body can be increased considerably in this way and that the firmness will consequently increase accordingly.

A possibility for according to the method according to the invention

to produce a band-shaped body, e.g. a glass-stack elf ribbon, is visualized in figures 2 to h. For this purpose, a channel is used, a so-called "spinning funnel" 11 which here is composed of cylindrical sections 12 and 13, the section 13 being wholly or partially provided with air outflow openings ih- and the section 12 opens into an outlet tube 15 from which the fiber strip FB is pulled out. The section 12 can of course also be designed as a truncated cone and this is where the term "spinning funnel" comes from. In the joint between the non-perforated and the perforated section, a driven over-lining ring 17 is suitably arranged which runs in rollers 16, and whose peripheral surface 18 projects into the space bounded by the spinning funnel. The fiber air stream flowing in the direction of arrow C over a guide device 19 in the width of the extraction drum into the spinning funnel 11 is first deflected in the direction of the rear end surface 20 provided with openings, while the fiber air stream tries to expand due to the path of least resistance to which the openings lh in section 13 opens possibility. At the same time, however, the fiber air stream turns into a more and more compressed vortex motion revolving around the spinneret axis 21, whereby of course the fibers flowing into the spinneret in the vicinity of the outlet pipe 15 are not deflected at all or not as much as the others in the direction of the one with air outflow openings 14- supplied section 13. From the vortex continuously standing up in the spinning funnel, the fiber band FB is pulled out perpendicular to the direction of the fibers' inflow. The first one.

proportion of inflowing fibers, however, first ends up in the cylindrical rear section facing away from the outlet rib 15 and then runs along the projecting inner peripheral surface of the transfer ring 17, whereby the liquid on the surface is released to the fibers. The lining surface can, for example, as illustrated in fig. 4-, is supplied with the liquid medium which is to be transferred to the fibres. Therefore, it can e.g. in the transfer ring 17. be arranged bores 22

which runs at an angle to the radii, with which the ring is supplied with the liquid medium from a supply container 23 and which, upon further turning in the direction of arrow D, ends up in the inner circumferential surface 18 of the ring.

In this way, practically all fibers in the so-called "fiber tail" are brought into contact with the blended liquid, which is why, of course, several separate transfer rings 17 can be arranged along the spinning funnel 11.

A further design example for the production of glass staple fiber tape is shown schematically in fig. 5- According to the invention, one or more slowly rotating transfer disks 24-a, 24-b and 24-c project into the spinning funnel, which can be offset by 120° in relation to each other, where the disk 24-a receives coating liquid from a storage container 25 and transfer disks 24-b and 24-c receive liquid from drip devices 26a and 26b. During the slow rotation of the disks 24-a and 24-c, the liquid coating agent ends up in the interior of the spinning funnel and is released from the surfaces of these transfer disks to the individual fibers moving in the "fiber tail".

Arrangement of several disks arranged in a plane perpendicular to the axis of the spinning funnel or lying along this axis, e.g. three discs, may be appropriate especially at high withdrawal speeds to achieve an equal distribution of the liquid coating agent in the band-shaped fiber body. The rear part, the so-called fiber tail, of the fiber-air vortex that builds up in the spinneret is in this part mostly not at rest, but as a whole carries out a circular movement that follows a movement path K shown with a dash-dotted line. Therefore, when e.g.

a fiber strip is pulled off at high speed and only a single transfer disc is present, it may happen that only part of the fibers come into contact with the coating agent, which will be noticeable as untreated areas appearing with gaps in the finished product.

The transfer disks 24-a to 24-c are conveniently arranged so that they can be adjusted so that more or less peripheral sections can protrude into the part 13 of the spinning funnel provided with air outflow openings. This makes it possible through the selection of revolutions and/or

by setting the corresponding depth to that in the spinning funnel and thus the part projecting into the fiber stream to set the proportion of pre-filed coating agent.

The rollers, rings or discs 7, 17 or 24 shown in figures 1 to 5 which transfer the coating agent to the individual fibers must only be considered as suitable and exemplary embodiments.

When an absorbent and capillary-conducting material is used, these transfer parts can also fulfill their task in the form of motionless rods, rings or disks. In addition, figures 6 to 7 show further particularly suitable and practically tested possibilities for applying a coating agent to the individual fibres. Figure 6 schematically shows an embodiment where a liquid transfer element in the form of an absorbent material, e.g. felt 28, is arranged in the spinning funnel 27 and extends over all or a substantial part of its width and which is continuously supplied from the outside with a liquid which is absorbed by the same. The felt protrudes just enough into the inner space 29 of the spinning hopper so that the fibers which flow in along the guide surface 30 of the turning device and then move in the vortex W at or near the inner surface of the spinning hopper, brush along the edge 31 of the felt protruding into the inner space and thereby receives coating fluid. For this purpose, the felt can be fixed in a housing 32 and the liquid can be taken from a container 33. The degree of coating depends on the absorbency of the felt, the liquid level in the container 33 and the length or depth of the protruding part 31-

Apart from the possibility that several of the devices described above can be used in combination, the intensity of the coating can be further increased. In the event that an extremely high proportion of liquid coating agent is required, e.g. over 1%, then the felt 28 can be removed. Instead of the felt wiper edge 31, a channel-shaped wiper lip 34 can be used which extends over almost the entire width of the spinning funnel and in which a constant liquid level can be maintained supplied from the container 33 through it now

empty housing 2, 2.. The individual fibers, which are in circular motion, stroke along this chute-like wiper lip and then receive their coating directly from the liquid.

Finally, figure 7 shows an embodiment example as in manufacturing

of glass staple fiber tape enables the use of a very simple and maintenance-free construction and with which a constant and precisely adjustable wetting of the fibers is achieved. In this embodiment, the liquid transfer element 36 is pushed into or suspended in a slot-shaped opening 35 which extends over all or a substantial part of the width of the spinning funnel, in such a way that it protrudes into the spinning funnel. Next to felt, a densely meshed wire cloth has proven beneficial, which is preferably pulled over a carrying tin 37- The end of the protruding part of the transfer element can then be slightly offset to offer the fiber air stream a certain resistance so that the fibers iron along it. Compared to felt, which wears out after prolonged use and loses its absorption capacity as a result of resin formation and hardening of non-evaporated components of coating liquid, the fine-mesh wire cloth has the advantage of less wear and longer service life. Moreover, fluctuations of the coating agent in the finished fiber product are avoided,

e.g. a fiber tape, which can occur when using felt due to the reasons mentioned above.

The wire cloth, which is preferably placed on a carrying case, is practical

virtually indefinitely durable and can be easily washed if soiling occurs. Over a dosing device (not shown), liquid is

coating liquid, e.g. an adhesive or color. The task of the wire weave is to distribute the applied liquid evenly and to hold it, otherwise there would be a risk that the applied liquid would run off or drip off uncontrollably from a smooth surface. A hinge 39 makes it possible to open the part ho in the spinning funnel for cleaning.

Claims (8)

1. Method for the production of glass fiber bodies, such as e.g. mats, filters, strings, bands, shaped bodies etc. where threads, which are produced in an arbitrary manner, are drawn out and off by means of a drum and on the withdrawal from the circumference of the drum are divided into fibers which are suspended in a continuous stream of air, fed along guide surfaces to a surface or into a space to form the fiber body and during removal of the air portion is compressed into a continuous fibrous body, the threads being fed to the drum being coated with a liquid which serves to increase adhesion to the drum surface during the withdrawal and also i.a. the mutual tearing strength of the fibers in the fiber body to be formed, and as another liquid treatment is carried out in a further, both temporally and positionally separated step, characterized in that the second liquid treatment of the individual fibers formed by the threads, and which are suspended in an air stream and lined along guiding surfaces, lined through for the fibers to be compressed to form the fiber body, the fibers being individually lined past treatment liquid-emitting opposite inglemehter which project into the fiber web. 2. Device for carrying out the method as stated in claim 1, with a glass fiber manufacturing device comprising a pull-off drum for extracting and pulling the arbitrarily produced threads, a stripper arranged to remove the threads from the circumference of the pull-off drum and to divide the threads into individual fibres, a subsequent guide device which consists of guide surfaces and is arranged to guide the fiber stream further to a surface or into a space for forming the fiber body, as well as a device for applying lubricant to the threads that come to the extractor drum and a device for applying a treatment liquid to the fibers that are suspended from the drum circumference, characterized in that the guide surfaces define a room which lines the fibers suspended in an air stream, where one or more transfer elements (7, 17, 24-a, 24-b, 2<4>-c, 28, 36) are arranged for applying the treatment liquid to the fibers as with a part of its surface protrudes into the aforementioned space for dispensing the treatment liquid during transfer. 3. Device as stated in claim 2, characterized in that the transmission elements (10, 17, 24-a,b,c) are designed as a rotatably stored dwarf transmission wheel, disc etc. which with part of the circumference forms part of the guide surface surfaces. 4-. Device as specified in claim 2, characterized in that the transfer elements (28, 36) are designed as a fixed liquid-dispensing device, e.g. felt strips (28), gutter-shaped squeegees (37) or tightly meshed wire cloth (36). 5. Device as stated in claims 2-4-, for the production of a ribbon-shaped fiber body, characterized in that the space delimited by the guide surfaces ends in a fiber vortex-forming spinning funnel (11, 13, 27, 29) from which the ribbon-shaped fiber body is drawn axially out, where the spinning funnel optionally comprises a section (13) with air outlet openings (14-) and a non-perforated section (12) and where the transfer elements (17, 24-a, b,c, 28, 36) project partially into the spinning funnel. 6. Device as stated in claim 5? characterized in that the transfer elements are designed as a rotatably mounted ring (17) which projects into the spinning funnel section (13) which is designed with air vent openings (14-) or is arranged between the two sections (13, 12). 7. Device as stated in claim 55 characterized in that it comprises a number of transfer rings (17) which are arranged concentrically with the spinning funnel axis and which with the inner circumference (18) project into the spinning funnel (11). 8. Device as stated in claim 5? characterized in that it comprises a number of transfer wheels (2k) arranged in one or more places along the axis of the spinning funnel (11).