JP2857564B2 - Regeneration method of filtration filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for regenerating a filter for filtering a polymer in a spinneret pack used in a melt spinning process of polyester.

[0002]

2. Description of the Related Art When producing synthetic fibers, spinneret packs used in the spinning process are periodically replaced to maintain fiber quality and operability, and exchanged by changing brands in accordance with high-mix low-volume production. In addition, they are exchanged in large quantities due to sudden replacement due to troubles. Of the components that make up the spinneret pack, the pack body, spinneret, rectifying plate, measuring plate, etc. are regenerated and recycled, but for the polymer filtration filter used in the pack,
Even if it is recycled and recycled, the economic profit is small (for example, a filter opening occurs during use, and the filtration accuracy is reduced).

However, recently, the price of wire mesh filters has risen, the amount of expensive metal non-woven fabric filters that are more efficient in filtering than wire mesh filters has been used has increased, and the disposal of waste has been reduced. From the economic and social standpoints, such as the improvement in the morals of the filter, there is a demand for a filter filter regeneration technology, but no efficient regeneration technology has yet been proposed.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a method for efficiently regenerating a once-used polymer filtration filter.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention.

That is, the present invention relates to a method for reusing a laminated wire mesh or a metal non-woven fabric filter of a spinneret pack used in melt spinning of polyester.
A gist of the present invention is a method of regenerating a filtration filter, wherein the treatment is performed in the following steps (1) to (5). (1) The used filter is disposed at a position at least one third higher than the bottom in the treatment tank filled with the organic solvent, and the solvent is heated to dissolve and elute the polymer adhered to the filter. (2) Remove the filter from the processing tank while the temperature of the solvent is 60 ° C or higher, and wash with water or hot water. (3) Separate the filter into a rim section and individual filter sections, and then treat the filter section with an alkaline solution. (4) After the filter section is washed with water or hot water, finish washing is performed with ultrasonic waves or a low-pressure fluid. (5) After drying the filter part, perform aperture inspection and re-lamination assembly.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIGS. 1A and 1B are plan views showing one embodiment of a laminated filter applied to the present invention. FIG. 1A shows a donut type filter, and FIG. 1B shows a round type filter. FIG. 2 (a),
(B) is sectional drawing of FIG.1 (a) and (b), respectively. The filter is a filter section A through which the polymer passes
And aluminum rims B and C for holding the ends of the filter portion A. The filter portion A is composed of three types of filters, E and F are support filters for reinforcement, and G is a main filter made of a wire mesh or a nonwoven metal fabric.

The support filters E and F usually use a wire mesh having a large porosity, and the main filter G made of a wire mesh or a metal nonwoven fabric usually uses a material having a small porosity. In addition, the filters E, F, and G in the present invention are not particularly limited, and may include a number of different combinations such as the number of layers and mesh types.

Next, a method for regenerating the doughnut-type three-layer laminated type filter shown in FIG. 2A using the solvent processing tank apparatus shown in FIG. 3 will be described in detail.

In the solvent treatment tank apparatus shown in FIG.
Has a double structure made of stainless steel. The inner tank is filled with the solvent 7, and the circulating heating medium is introduced from the heating medium inlet / outlet H into the outer tank. The heating heat medium is sent from a heat medium inlet / outlet J to a heating circulation device (not shown) to heat the solvent 7 filled in the internal tank to a target temperature. In addition, a heater 9 for keeping heat is provided in an outer layer portion of the processing tank 1 in order to prevent temperature unevenness of the solvent 7. An opening / closing lid 2 is provided at an upper portion of the processing tank 1 so that a filter 5 set in a basket 4 can be inserted through a gasket 6, and a cooler 3 extending upward is provided at the center. . Cooling water introduced from the cold water inlet / outlet V and discharged from W is circulated in the cooler 3, and the vaporized solvent 7 is cooled and liquefied and returned to the processing tank. The temperature of the solvent 7 can be confirmed at the temperature detecting end 8, and the target temperature can be maintained by controlling the heating heat medium.

In the step (1), the used filter 5 is
It is disposed at a height of at least 1/3 from the bottom of the inner tank of the processing tank 1 filled with the solvent 7, and the solvent 7 is heated to dissolve and elute the polymer attached to the filter 5. If the position of the filter 5 is less than 1/3 of the bottom of the inner tank of the processing tank 1, the adhered polymer is dissolved with the heated solvent 7, and the precipitate of the dissolved polymer is again removed from the filter section A where the polymer is removed. Since they adhere to, permeate, and contaminate, they cannot be completely removed even if they are washed in a later step.

The upper limit position of the filter 5 is not particularly limited. However, when the vapor of the solvent 7 is cooled and liquefied by the cooler 3 or the like and refluxed, if the vapor is directly in contact with the filter 5, the temperature inside the filter 5 becomes lower. Drops, dissolves,
Since the elution efficiency is reduced, it is preferable to set the position where the solvent vapor does not contact.

Filter 5 after use with polymer attached
Is arranged at a height of 1/3 or more from the bottom surface of the processing tank 1 filled with the solvent 7, for example, a space divided into several stages is provided in the basket 4, and There is a method in which the filter 5 is set so as not to overlap on a stage having a height of / 3 or more, and the basket 4 is immersed in the treatment tank 1 together.

Although the temperature for heating the solvent 7 and the time for immersing the filter 5 differ depending on the type of the polymer adhered to the filter 5, the temperature for heating the solvent 7 depends on the type of the polymer.
It is preferable to heat to a temperature lower than the flash point so as to prevent ignition, steam deterioration of the environment, and burns.

The organic solvent used in the step (1) is not particularly limited as long as it is a solvent in which the polyester is soluble, but from the viewpoints of solubility, safety (high flash point), etc. Ethylene glycol and tetraethylene glycol are particularly preferred.

In the step (2), the polymer is dissolved in the step (1),
The eluted filter 5 is taken out of the processing tank 1 and
Washing is performed with water or hot water. At this time,
Since the solvent 7 is heated to a high temperature in order to dissolve the polymer in (1), the filter 5 is taken out after the temperature of the solvent 7 is lowered for safety. It is necessary to take out the filter 5 from the tank, more preferably at 70 ° C. or more.
When the temperature of the solvent 7 is lower than 60 ° C., the viscosity of the solvent 7 increases, and the suspended matter of the dissolved polymer which has not been completely precipitated during the temperature lowering adheres to the filter portion A when the filter 5 is taken out from the treatment tank 1. Is not preferred.

Next, the solvent 7 and the polymer residue remaining on the filter 5 are washed away with water or hot water. This washing may be performed by a usual method in consideration of drainage management. However, in order to increase the washing efficiency, a method of washing by performing a bubble shower with water or air from the bottom of a hot water tank is preferable.

In the step (3), the aluminum rims B and C of the washed filter 5 are cut and removed with scissors, nippers or the like so as not to damage the end of the filter portion A. , F and a main filter G made of wire mesh or metal nonwoven fabric, separated and treated with an alkaline solution in order to dissolve polymer residues that could not be completely removed in step (2). The alkaline solution referred to in the present invention includes a sodium hydroxide solution, a potassium hydroxide solution, and the like. It is preferable that the filter is arranged and immersed in these alkaline solutions so that the filter does not overlap. The separated aluminum rims B and C are used as aluminum for recycling.

In the step (4), first, the filters E, F and G treated with the alkaline solution are washed with water or hot water,
Remove the attached alkaline solution. At this time, if the washing is insufficient, there is a risk that a worker working in the next step may suffer a chemical injury, so that sufficient washing is necessary. Note that, similarly to the washing in the step (2), the washing efficiency is good if the washing is performed by a bubble shower with air from the bottom of the water or hot water tank.

Next, the filters are subjected to finish cleaning with ultrasonic waves or a low-compressed fluid to completely remove foreign matters adhering to the filters. At this time, if the main filter G made of a wire mesh or a metal nonwoven fabric having a small gap has an opening or the like, the filtering accuracy is affected.

In the step (5), the filters E, F, and G, which have been finished and cleaned, are dried, then subjected to a mesh inspection and a re-lamination assembly. After the filters E, F, and G are dried by a hot-air dryer, for example, a box-type milling cutter, a mesh inspection is performed. Since the support filters E and F are for reinforcement, the wire used is thick, and the gap is large and durable, it is sufficient to inspect the aperture and check for residue adhesion visually or by a projector.

Next, since the filtration accuracy of the main filter G made of a wire mesh or a metal nonwoven fabric having a small gap is important, an aperture inspection and a residue adhesion check are performed using a light transmission microscope or a projector. .

The filters E, F, and G that have passed the above-mentioned opening inspection are laminated and assembled again, but the main filter G made of wire mesh or metal nonwoven fabric is reinforced and laminated with the support filters E and F. Next, new aluminum rims B and C
By setting and fixing the press so that it does not move,
Regenerate filter 5.

The polyester as used in the present invention is a polyalkylene terephthalate or a copolymerized polyester containing the same as a main component, and includes organic substances such as a matting agent, a light-proofing agent, a heat-resistant agent, an antistatic agent, a conductive agent, and a pigment. It may contain an inorganic additive.

[0025]

Next, the present invention will be described specifically with reference to examples.

Example 1 Polyethylene terephthalate (containing titanium dioxide, 5% by weight) having an intrinsic viscosity of 0.65 (measured at 20 ° C. using an equal weight mixed solvent of phenol and ethane tetrachloride) was used as a core component. Is 0.60 polyethylene terephthalate (titanium dioxide, containing 0.5% by weight) as a sheath component.
A core-sheath type composite yarn having a sheath volume ratio of 60/40 was spun at a spinning temperature of 29.
168 hours (7 days) after attaching the spinneret pack under the manufacturing conditions of spinning at a speed of 3000 m / min at 0 ° C, a total discharge rate of 82 g / min, and spinning from a spinneret having 48 orifice holes at a speed of 3000 m / min.
, The pack components for 36 attachment weights were disassembled, and the used filtration filters were collected. Figure 2 shows the core polymer filtered out of these filters
FIG. 3 shows a three-layer laminated round filter (main filter G; stainless steel nonwoven fabric filter having an average porosity of 20 μm, support filters E and F; 80-mesh plain woven wire mesh) shown in FIG. Step (1) using
(5). The processing tank 1 has a cylindrical shape with a bottom.
The diameter was 40 cm, the height to the lid was 80 cm, the amount of solvent penetration (height) was 60 cm from the bottom, and unused tetraethylene glycol (boiling point: 327 ° C.) was used as the solvent. The number of filters to be regenerated was 24 sets, and the filters were set in a wire mesh basket. The washing conditions and the treatment conditions of the alkaline solution in each step are as follows. (1) The filter was placed at a height of 1/3 from the bottom in the solvent treatment tank, and the polymer was dissolved and eluted at a solvent temperature of 275 ° C and a treatment time of 3 hours (after the temperature was stabilized). (2) The temperature of the solvent was lowered, and the filter was taken out at 80 ° C., and washed with warm water of 50 ° C. from the floor of the washing tank with a bubble shower using air for 10 minutes. (3) The filter was separated into a rim portion and individual filter portions, and the separated filter portions were set in a wire mesh basket and immersed in an alkali solution (concentration 20% sodium hydroxide solution) treatment tank at 80 ° C. for 30 minutes. . (4) The filter was washed for 10 minutes in hot water at 50 ° C. while being subjected to a bubble shower with air from the floor of the washing tank. Further, after finishing washing with ultrasonic waves in hot water at 60 ° C. for 5 minutes, adhered water was removed with air at a pressure of 1 kg / cm ² . (5) Perform hot drying at 80 ° C for 15 minutes.
A mesh inspection was performed. The support filters E and F were visually inspected for opening, but hardly any residue was attached. The main filter G made of wire mesh or metal nonwoven fabric is
Using a projector and a light transmission microscope, a 10-point aperture test was performed at random for each sample to check for residue adhesion. Evaluation of residue adhesion was performed in the following four stages. ◎ ・ ・ No residue ○ ・ ・ Some residue △ ・ ・ A little residue × ・ ・ Less residue

Example 2 The same procedure as in Example 1 was carried out except that the position of the filter in step (1) and the solvent temperature at the time of removing the filter in step (2) were changed.

Comparative Example 1 The procedure of Example 1 was repeated except that the solvent temperature at the time of removing the filter in step (2) was changed, and the washing with hot water in step (2) was not performed.

Comparative Example 2 Same as Example 1 except that the solvent temperature when removing the filter in step (2) was changed, and the treatment with the alkaline solution in step (3) and the washing in step (4) were not performed. I went to.

Comparative Example 3 The same procedure as in Example 1 was carried out except that the solvent temperature at the time of removing the filter in step (2) was changed and the final washing in step (4) was not performed.

Comparative Example 4 The same procedure as in Example 1 was carried out except that the position of the filter in step (1) was changed.

Comparative Example 5 The same procedure as in Example 1 was carried out except that the position of the filter in step (1) and the solvent temperature at the time of removing the filter in step (2) were changed.

Comparative Example 6 The procedure of Example 2 was repeated except that the solvent temperature at the time of removing the filter in step (2) was changed.

Table 1 shows the processing conditions and the results of the residue evaluation performed in Examples 1 and 2 and Comparative Examples 1 to 6.

[0035]

[Table 1]

As apparent from Table 1, the laminated filters treated in Examples 1 and 2 were in a good condition with almost no residue.

In Comparative Example 1, there is no washing in the step (2). In Comparative Example 2, there is no alkaline solution treatment in the step (3). In Comparative Example 3, there is no finishing washing in the step (4). Therefore, in each case, the polymer remained in the filter. In Comparative Example 4, the filter position in the step (1) was 1 /
Therefore, in Comparative Example 5, the filter position in step (1) was less than 1/3 and the solvent temperature was 45 ° C.
, The polymer was not sufficiently dissolved. In Comparative Example 6, since the polymer was taken out when the solvent temperature was 35 ° C., a large amount of polymer remained in the filter in each case.

Example 3 Using the laminated filter subjected to the regeneration treatment of Example 1, the same melt spinning as in Example 1 was repeated five times, and the number of regenerations of the filter and the operability were evaluated. Was done. The manufacturing conditions were the same as in Example 1 except that the number of mounting weights was eight. The evaluation of the characteristic values is as follows. ΔP: pressure difference between the spinneret pack at the time of installation and at the time of 168 hours. Number of thread breaks: Number of thread breaks per total weight up to 168 hours after installation. Number of foreign substances generated: Four spools were sampled from the yarn collected after 168 hours, and when the yarn was passed through a ceramic slit guide at a length of 10 ⁴ m, foreign matter in the yarn caught between the slits ( This is the average of the number of insects.
The gap between the slits was a portion where no foreign matter was present, and was limited to a narrow width (about 25 to 30 μm) so as not to be caught by the slits.

Table 2 shows the results of the evaluation.

[0040]

[Table 2]

As is clear from Table 2, ΔP gradually increases as the number of regeneration treatments increases. However, as the size of the openings increases, the pressure of the spinneret pack gradually decreases. The number of occurrences increases. Therefore, it was possible to use the filter with good operability up to a filter having three times of regeneration processing, and it was possible to regenerate and use the filter five times in consideration of the intended use.

Comparative Example 7 The same procedure as in Example 3 was carried out except that the regeneration treatment of the laminated filter was performed under the conditions of Comparative Example 4. as a result,
The pressure difference of the spinneret pack reaches the maximum of 50 kg / cm ² after 72 hours of the first regeneration, and the pressure difference of the spinneret pack reaches the maximum after about 24 hours of the second regeneration filter. It reached a certain 50 kg / cm ² , the number of thread breaks and the number of foreign matters generated were large, and it was not very useful in the manufacturing process.

[0043]

According to the present invention, since the polymer filter once used can be efficiently regenerated, the production cost can be reduced without lowering the quality and operability of the obtained yarn. , Resources can be effectively used.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a laminated type filter according to the present invention.

FIG. 2 is a cross-sectional view of the laminated filter of FIG.

FIG. 3 is a schematic sectional view showing one embodiment of a solvent treatment tank device used in the present invention.

[Explanation of symbols]

 A Filter section B, C Aluminum rim E, F Support filter G Main filter made of wire mesh or non-woven metal fabric 1 Processing tank 2 Lid 3 Cooler 4 Basket 5 Filter 6 Gasket 7 Solvent 8 Temperature detection end 9 Heating heater H, J Heat medium in / out Part V, W Cold water inlet / outlet

Claims (1)

(57) [Claims] 1. The method of claim 1, wherein the polyester is used in melt spinning.
A method for regenerating a filtration filter, comprising performing the following steps (1) to (5) when reusing a laminated wire mesh or a metal nonwoven fabric filter of a spinneret pack. (1) The used filter is disposed at a position at least one third higher than the bottom in the treatment tank filled with the organic solvent, and the solvent is heated to dissolve and elute the polymer adhered to the filter. (2) Remove the filter from the processing tank while the temperature of the solvent is 60 ° C or higher, and wash with water or hot water. (3) Separate the filter into a rim section and individual filter sections, and then treat the filter section with an alkaline solution. (4) After the filter section is washed with water or hot water, finish washing is performed with ultrasonic waves or a low-pressure fluid. (5) After drying the filter part, perform aperture inspection and re-lamination assembly.