DE2531401A1 - METHOD AND APPARATUS FOR MANUFACTURING A FILTER, AND FILTER MANUFACTURED BY THE METHOD AND APPARATUS - Google Patents

Description

253Η0Ί

PATETJTANWALTE A. GRÜNECKER

DIPL-ING

H. KINKELDEY

Dft-ING

W. STOCKMAIR

URGENT. AoE (CALTECH

K. SCHUMANN

DR BER NAT. - 0IfV-PHVS

P. H. JAKOB

DCPU-ING.

G. BEZOLD

DR. HER NAT.- DlFL-CHEM.

MUNICH

E. K. WEIL

OR FBiOEC ING

8 MUNICH 22

MAXIMILIANSTRASSE 43

P 9408

14-. July 1975 BRUNSWICK CORPORATION

One Brunswick Plaza Skokie, Illinois 6OO76

United States

LINDAU

Method and device for producing a filter and filters produced by means of the method and device

The invention relates to a method and a device for producing a filter and to a method and a device of the device manufactured filter. The invention is used in particular for the production of filter cartridges or filter inserts Use.

So far, filter cartridges! produced in that a fibrous Yarn or sliver has been wrapped around a tubular body or mandrel. The tubular body is formed by a relatively stiff, perforated core that remains in the yarn after the yarn has been wound up, so that the filter has the required strength during operation.

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There are also other filters known that do not have a central one Core is provided and the rigidity of the wound fibers is achieved in that the fibers with an additional Binders are glued together by impregnating the filter cartridge with a synthetic resin, which then hardens.

The yarn is generally made from a raw textile material produced, which is processed into long carding belts by means of a carding or combing machine, so that a untwisted carding tape or so-called roving is produced. The roving can then be twisted to form a roving will be produced. The twisted rovings or roving are generally becoming more conventional with the filter candles Kind of processed. By using tightly twisted Pre-spun is the filtration performance of conventional filters or the filter property in order to a certain extent limited. The only way to improve filtration performance Changing conventional filters consists of changing the type of winding in the manufacture of the filter.

The invention is directed to a method and an apparatus to create a filter of the aforementioned type, which has the disadvantages of yarn or roving does not have manufactured known filter. The invention is further directed to a method and an apparatus to provide a more permeable filter which allows particles to pass through freely that have smaller dimensions than the particles to be filtered. At the same time, the method according to the invention is intended to reduce the Allow manufacturing costs of filter cartridges.

The method according to the invention for producing the filter

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is that a fibrous roving or the top is treated with a hardening agent serving to stiffen the roving, that the stiffened roving is spirally wound onto a core and that the wound roving is glued Candle wound, this filter candle does not have the disadvantages of filters made from twisted yarns. The starting material for the production of the filter candle according to the invention is a combed roving, which consists of a soft, untwisted fiber band and has an essentially circular cross-section. The roving can be made of any fibers and are produced on carding machines processing cotton or wool or worsted yarn The denier number of the fibers used to produce the roving has a great influence on the filtration properties in around the finished filter candle.

The roving used as the starting material is treated with a hardening Impregnation agent impregnated, which gives the roving extra strength. The roving can thereby given a ribbon-like shape that it passes through a funnel during impregnation. The excess Resin is removed with the aid of a set of nip rollers, and then the roving impregnated with the resin is removed dried at a temperature below the curing temperature of the synthetic resin.

A winding machine is provided for winding the roving impregnated with the synthetic resin onto a supporting core, which has a driven spindle, a pressure roller and a winding head. The core can be in the finished filter cartridge remain or be removed from the filter candle after the resin has hardened. The pressure roller or com-

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Pressionsvorrichtung exerts an externally acting pressure on the wound roving, while the winding head a Introduces tensile stress in the roving to be wound, so that the density of the filter when winding successively Roving layers can be changed in an advantageous manner. The roving is either parallel, helical Windings wound on the core or in crisscrossing or diamond-shaped windings. Thereby the winding designed in such a way that the individual roving layers extend somewhat beyond the ends of the supporting core.

The ends of the filter cartridge are formed in that on the ends of the wound filter cartridge are arranged flat closure body and that the filter cartridge is then inserted compressed between two stationary end walls of a compression device specially designed for this purpose will. The filter pakraoe becomes like this during the pressure load treated that the layers of the wound roving stick together, while at the same time the further hardening of the Synthetic resin and thus the stiffening of the roving takes place. If a thermosetting resin is used for stiffening of the roving is used, then a pre-consolidation of the roving takes place during the drying of the impregnated roving instead of and a final solidification and sticking during the hardening of the wound roving yarn. After hardening the finished filter cartridge can be machined and provided with grooves, for example.

A significant cost saving in the manufacture of the filter cartridge using the method according to the invention is achieved in that a roving is used in which Production one process step is saved compared to the production of conventional twisted yarns.

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Further features, details and advantages of the invention result from the following description of exemplary embodiments with reference to the drawing. Show in it:

1 shows a side view of a filter cartridge provided with grooves, which is produced by the method according to the invention;

2 shows a side view of a filter candle in which the windings run in a cross or diamond shape, with the filter paper using the method according to the invention is made;

3 shows a sectional view of the filter cartridge shown in FIG. along section line 3-3;

4 shows a schematic representation of the first method steps of the method according to the invention;

5 shows a partial illustration of further process steps of the method according to the invention;

6 shows a partial sectional view through the at the end of the process used compression device along the line 6-6 of Figure 7;

7 shows a side view of the compression device and

8 shows a side view of a in connection with the in the Fig.6 and 7 shown compression device used closure body.

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The filter cartridges with the method according to the invention are shown in FIGS. 1, 2 and 3. The filter cartridge 10 shown in Figure 1 is produced in that a stiffened roving in parallel Layers is helically wound around a supporting core. In the filter cartridge are then incorporated several grooves 12, so that the outer surface of the filter plate is enlarged. The filter cartridge 14 shown in Figures 2 and 3 was produced by that ribbon-shaped, synthetic resin-soaked rovings are wound around a supporting core with a cross-shaped or diamond-shaped pattern became. The density of the roving of the filter 14 increases towards the center of the filter cartridge, so that the An increasingly better filtration of smaller particles is achieved in the middle of the filter cartridge. Due to the irregular The surface created by the ribbon-shaped roving and the cross-shaped or diamond-shaped pattern becomes the outer surface the filter cartridge enlarged without the need to incorporate grooves. The filter cartridge 14 has as middle core 16 a perforated carrier, which can be a permanent part of the finished filter cartridge or after Hardening of the wound synthetic resin-soaked roving can be removed from the filter cartridge.

As shown in Fig.4, a fibrous roving 18 made of wool, cellulose acetate, viscous rayon or other natural fibers or synthetic fibers from a storage container 20 pulled out and over rollers 22 of a station for impregnation with a hardening impregnation agent fed. The roving 18 runs through a funnel 24 so that a thread-like roving shown in FIG. 2 is formed will. The funnel 24 is substantially conical and has a small rectangular or at its end

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elliptical opening. It should be noted, however, that the funnel 24 can also be omitted and the roving 18 in the untreated form with which it is made is withdrawn from the reservoir 20, is impregnated. By using the funnel 24, it becomes more uniform Thread generated so that a more uniform filter cartridge is produced.

While the roving 18 passes through the funnel 24, it is impregnated with a synthetic resin fed through a pipe 26. The synthetic resin, which is a thermosetting one Impregnation agent can be formed from a solution containing phenol-formaldehyde, urea-formaldehyde or contain other curable components. The synthetic resin is from a storage container 28 by means of a Pump 30 is fed to pipe 26. The preformed roving 18 impregnated with synthetic resin runs through two pairs of squeegee rollers 32, through which excess resin is removed. Two pipes 34 lead the excess resin off Collecting channels or drip trays to the storage container 28 back.

The impregnated roving 18 is then prevailing at a significantly below the curing temperature of the synthetic resin Temperature dried in an oven 36. By means of a fan 38, air is drawn into the furnace 36 and connected to electrical Heaters 40 conveyed past. The heated air is discharged by means of a fan arranged at the outlet of the furnace 36 32 sucked past the roving 18. The roving 18 loops around rollers 44 and 46 in multiple loops so that it traverses the length of oven 36 multiple times. This Method for drying the resin-impregnated roving allows the simultaneous processing of an enlarged

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Roving length so that the resin can cure without the need to increase the height of the oven 36. That dried roving 18 exiting oven 36 is wound onto a bobbin 48.

The dried, synthetic resin-impregnated roving 18 is of withdrawn from the spool 48 and wound onto a perforated, supporting core by means of a winder, like this is shown schematically in Fig.5. The roving 18 is passed through one or more guide eyes 50, which apply a tension controlled by a calibration device 52 to the roving. The tensioned roving 18 runs then by a guide device 54, which is given a reciprocating motion by means of a spindle 56. The design of the spindle 56 is decisive for whether the pattern according to FIG. 1 with a parallel thread course or the pattern is formed according to Figure 2 with intersecting threads.

The perforated central core 16 is rotated by means of a shaft 58 during winding.

One or more compression rollers 60 are provided which exert a radial compressive force on the roving 18 while it is wound onto the perforated core 16. By changing the pressure of the compression rollers and that of The tensile force applied to the winding head can change the packing density of successive layers of roving in the filter. The roving is applied helically to the supporting core 16 with the turns slightly over the ends of the supporting core 16 also extend. The ends of the filter cartridge are then placed under the application of an axial force Filterpafcraae deformed, whereby the axial force during the ab-

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final hardening acts uninterruptedly. The cured, finished filter cartridge can then be used in its unchanged condition are or are processed, so that the shape shown in Figure 1 results.

The method according to the invention was carried out, for example, using a liquid impregnating agent. This liquid impregnating agent was an aqueous solution of the phenol-formaldehyde resin with a solids content of 20 to 30%. The impregnated roving was dried at an oven temperature of about 100 to 200 ° C (200 to 400 ° F) for approximately 4 to 6 minutes. Other times and temperatures can be used for rovings of other weights and deniers and other impregnation mixtures. The wound filter cartridge under pressure then cured in a standard oven with air circulation at a temperature of about 160 ° C (320 ⁰ F) approximately one hour from long. Then the filter cartridge was taken out of the oven and could be used for filtration. For example, roving with a weight of 4.25 to 8.5 g / m (60 to 120 grains per yard) with fibers of different strengths brought the following filter performance:

Fiber blend

100% 3 denier 50% 3 denier - 50% 15 denier 25% 3 denier - 75% 15 denier 10% 3 denier - 90% 15 denier

100% 15 denier

Filter performance in ,around

1 cm

5 yum 10 yum 25 yum 50 um

Obviously, the best filter performance is achieved by that fibers with suitable fiber strengths are sorted out beforehand.

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6 to 8 show a Konipressionsvorrichtung with which an axial compressive force is applied to the filter cartridge while it hardens. The compression device has two identical end walls 64, which are held together by means of four tie rods 66, which in turn by means of fastening devices 68 are attached to the end walls. By using the tie rods 66 to connect the end walls 64 has the lateral area of the space between the end walls essentially no obstacles, so that the core is made more uniform. Two closure bodies 70, which are shown in FIG. 8, and a head part 72 and a shaft 74 with a bevel 76 can be found in Connection to the compression device 62 use. The closure body 70 is used in such a way that the shaft 74 is received in the wound filter cartridge so that the Ends of the filter cartridge between the end faces of two closure pieces 70 are included. Each closure body 70 has a bore 78 through which the bounded by the core Interior is accessible during curing. In the end walls 64 of the compression device 62 is in each case a recess 80 is provided in which the head part 72 of a closure body 70 is received. The end walls 64 are beveled at the points 82, so that when the closure body 70 is inserted, a compressive force is exerted on the filter cartridge is exercised when the closure bodies are displaced to the bottom of the recess 80. There are holes in the end walls 64 84 arranged, which coincide with the bores 78 of the closure body 70 when these are inserted into the recess 80, so that a connection to the interior space delimited by the core is established during curing. At the end of the compression device a handle 86 is attached, which the hand

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Handling of the device during the curing process is facilitated.

The end walls 64 are arranged at a distance from one another, which is smaller than the length of the wound filter cartridge is, so that an axial force is exerted on the filter cartridge when it is inserted into the recesses 80. at The compression device is an inexpensive device that uses the filter cartridge during curing a compressive force is applied and holds.

In deviation from the above description of the subject matter of the invention, it is of course also conceivable that the stiffening of the roving can be done using heated thermoplastic synthetic resins that cool down Harden. Chemically reacting hardeners such as epoxy resins to stiffen the roving could also be used be used for a long enough time. Hard agents with solvents could also be added, with the solvent evaporates during drying. The wound rovings are glued together by the subsequent Curing of the hardening agent or by treating the wound filter cartridge with an additional binding agent.

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Claims (25)

253H01 P 9408 Claims Process for the manufacture of a filter, characterized in that a fibrous roving is treated with a hardening agent serving to stiffen the roving so that the stiffened roving is spirally shaped is wound on a core (16) and that the wound roving is glued. 2. The method according to claim 1, characterized in that that the roving is impregnated with the hardening agent used to stiffen the roving and then is treated in such a way that the roving has sufficient structural strength so that undesirable compression of the roving structure is prevented during winding. 3. The method according to claim 1 or 2, characterized in that the hardening agent is under the influence cures by heat and the aftertreatment comprises a drying process that occurs at a temperature below the curing temperature lying temperature is carried out. 4. The method according to any one of claims 1 to 3, characterized in that the curing agent is an epoxy resin is used and the post-treatment time is such that a complete chemical curing of the epoxy resin is guaranteed. 5. The method according to any one of claims 1 to 4, characterized in that the hardening agent is a solvent 509885/0971 has medium, which is evaporated during the aftertreatment. 6. The method according to any one of claims 1 to 5, characterized characterized in that the curing of the roving is continued even during the gluing. 7. The method according to claim 1, characterized in that the fibrous roving is pre-stretched before it is wound up in the form of a thread. 8. The method according to any one of claims 1, 2 and 1, characterized in that the roving is wound up according to a cross or diamond pattern (see Figure 2). 9. The method according to claim 7, characterized in that the roving for pre-stretching is drawn through a funnel (24) during impregnation. 10. The method according to any one of claims 1 to 8, characterized in that the roving during the winding is subjected to pressure radially to the core (16). 11. The method according to claim 10, characterized in that the pressure load with rollers is applied and that the tensile force introduced into the roving is changed during winding. 12. The method according to claim 10 or 11, characterized in that the pressure load selected 509885/0971 25 3 H Ol rend of the winding of successive layers of roving is changed. 13. The method according to any one of claims 1 to 6, characterized characterized in that the wound roving during gluing in the axial direction of the core (16) is pressurized. 14. The method according to claim 13, characterized in that the axial pressure load is brought about by inserting the wound roving between two stationary surfaces (64), the distance between which is smaller than the length of the wound filter candle (10, 14). 15. The method according to claim 1, characterized in that the filter cartridge (10) for enlargement the outer surface is machined on its lateral surface. 16. Device for performing the method according to a of claims 1 to 15, comprising a compression device for making tubular articles, thereby characterized in that two walls (64) arranged at a lateral distance from one another are provided, which are fixed to one another by a connecting device (66) in such a way that laterally in the between the walls There are essentially no obstacles in the lying space and the space is only limited by the walls is, wherein the distance between the walls is smaller than the length of the tubular objects, so that they are inserted be compressed. 5 0 9885/0971 253H01 17. The device according to claim 16, characterized in that the connecting device tie rod (66). 18. The apparatus according to claim 16, characterized in that each side wall (64) has one Has recess (80) into which the tubular object is inserted and held. 19. The device according to claim 18, characterized in that the flanks of the recess (80) are beveled in the area of the inlet cross-section, so that the tubular object when inserted into the Recess is compressed. 20. Device according to one of claims 16 to 19, characterized characterized in that two closure bodies (70) are provided, each having a head piece (72) and have a shaft (74), and that the head piece in the recess (80) and the shaft in the opening of the tubular Object to be recorded. 21. Device according to one of claims 16 to 20, characterized in that the side walls (64) and the closure body (70) each have a hole (84), the holes coinciding when the closure body are inserted into the recesses (80) so that the interior of the tubular body is accessible is. 22. Filter, characterized by a fibrous roving, which acts under an from the outside Compressive force spirally to form a tubular body 509885/097 1 253H01 is wound and which is treated with a hardening impregnation agent, which in the hardened state ensures that the tubular body is under pressure Maintains the shape achieved. 23. Filter according to claim 22, characterized in that that the roving has the shape of a ribbon. 24. Filter according to claim 22 or 23, characterized in that the roving is wound spirally so that a cross or diamond pattern is created. 25. Filter according to one of claims 22 to 24, characterized in that the roving in successive Layers is wound under the influence of a different compressive force, so that the filter over the cross section has a different density in the individual layers. 509885/0971 Blank page