JPH0427625Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a filter member for polymers used in the production of films and fibers such as polyester and polyamide.

[Conventional technology]

When producing fibers or films by extruding molten polymer through a die or die, removing foreign matter and gel from the polymer is an extremely important issue in terms of product quality, and various filters have been developed and used. As one example, a leaf filter 1 shown in FIG. 4 is known. This leaf filter 1 is constructed by stacking thin disc-shaped filter media 2, 2 made of sintered metal fibers and having an opening in the center as a filter member, and fixing the outer periphery 2B by, for example, welding, and Coarse wire mesh 3 for forming air gaps
and perforated plates 4, 4 for supporting filter media. The filter media 2, 2 are usually composed of a sintered body of long metal fibers, and have an average mesh opening of 5 to 5.
40μ, thickness is about 0.2 to 2 mm. Such leaf filters 1 are stacked to form a filter unit around a polymer discharge pipe having a polymer conduction hole on the outer circumferential surface by using the central opening,
The polymer to be filtered enters the cavity 5 in the leaf filter 1 from the outside of the leaf filter 1 through the filter media 2, 2, and is taken out from the opening 2A to a polymer discharge pipe (not shown). During this filtration action, the filter media 2, 2 alone do not have enough rigidity to withstand the filtration pressure, so they are supported by the perforated plate 4 and the wire mesh 3.

[The problem that the idea aims to solve]

By the way, the sintered body of metal fibers constituting the filter medium 2 can have a large porosity even though the opening can be extremely small, and is extremely effective in removing solid foreign matter from the polymer. However, because metal fibers have a smooth surface, there is a problem in that they are not very effective in crushing and removing gel in polymers.

The present invention aims to solve such conventional problems, and provides a polymer filter member that can be used in a polymer filter to effectively remove foreign substances from the polymer and crush and remove gel. The purpose is to

[Means to solve the problem]

The present invention, which was made to achieve this purpose, consists of a first filter medium made of a sintered body of metal fibers, and a sintered metal having a larger average opening than the first filter medium in the flow direction of the polymer to be filtered. The gist is a polymer filter member formed by laminating a second filter material.

Here, the first filter medium is made to have a mesh size and thickness that can ensure the desired final filtration accuracy for foreign substances in the polymer, and for example, similar to the filter medium used in conventional leaf filters, The average opening is 5 to 40μ, and the thickness is about 0.2 to 2mm.

The average mesh opening of the second filter medium is selected to be larger than that of the first filter medium, usually 20 to 100μ, preferably
The thickness is selected to be approximately 30 to 60μ. Also, the thickness is 1 to 3
Approximately mm is preferable. The sintered metal constituting the second filter medium is one obtained by sintering granular metal or short metal fibers, and among these, one obtained by sintering short metal fibers arranged horizontally at random is preferable. Such a sintered body of short metal fibers is preferable because it can increase the porosity even if the opening is reduced, is less likely to cause clogging, and is effective in trapping and crushing gel.

[Effect]

In the polymer filter member configured as described above, the passing polymer first passes through the first filter medium having a small opening, and solid foreign matter in the polymer is removed with high accuracy here. In this case, since the first filter medium is a sintered body of metal fibers, it is possible to increase the porosity even if the opening is reduced, and filtration is possible without increasing the filtration pressure too much.

The polymer that has passed through the first filter medium then passes through a second filter medium of sintered metal. Since this second filter medium is a sintered body made of granular metal or short metal fibers,
The effect of crushing and removing gel is large, and the gel that has passed through the first filter medium can be captured well. Also,
This second filter material has a large opening, so
Filtration is possible without increasing the filtration pressure too much.

Thus, the polymer filter member having the above structure is capable of trapping foreign matter and gel well without significantly increasing the passage resistance of the polymer.

In addition, since the second filter medium is laminated behind the first filter medium, by providing appropriate rigidity to the second filter medium, it is possible to support the first filter medium, which has relatively low rigidity, against the filtration pressure. It is also possible to make it act as a body.

〔Example〕

Hereinafter, an embodiment in which the present invention is applied to a leaf filter will be described with reference to FIGS. 1 to 3.

In FIG. 1, a leaf filter 7 according to an embodiment of the present invention has thin disc-shaped first filter media 2, 2 having an opening 2A in the center, and a coarse wire mesh 3 for forming a gap in the center. There is. A second filter medium 8 is arranged on both sides of the wire mesh 3. This first filter medium 2 and second filter medium 8
constitute the filter member of the leaf filter, and both have approximately the same diameter, and are stacked with a porous sintered metal ring 9 sandwiched between them, and the outer periphery is further integrated with a welded part 10. is combined with The ring 9 has approximately the same thickness as the wire mesh 3, so that the first filter medium 2,2 and the second filter medium 8,
There is no need to bend the outer peripheral portion of the leaf filter 8 as in the conventional leaf filter 1, which is preferable. Note that the ring 9 is omitted and the conventional leaf filter 1 shown in FIG.
The first filter medium 2 and the second filter medium 8 may be bent and joined and fixed to each other as shown in FIG.

For the first filter media 2, 2, a sintered body of long metal fibers similar to the filter media in conventional leaf filters is used, and the average mesh opening is about 5 to 40μ, and the thickness is
It is about 0.2 to 2 mm.

A porous sintered metal made by sintering granular metal or short metal fibers is used for the second filter media 8, 8,
The average mesh size is selected to be larger than the average mesh size of the first filter medium 2, and is usually selected to be about 20 to 100μ, preferably about 30 to 60μ. Also, the thickness is 1
The thickness is preferably about 3 mm. In this embodiment, the second filter media 8, 8 act as a support for supporting the first filter media 2, 2 against the filtration pressure, and as shown in FIG. 2, when receiving the filtration pressure, Although it is supported by the wire mesh 3, it has enough rigidity to support the first filter media 2, 2.

The same sintered metal as the second filter medium 8 can be used for the ring 9. This ring 9 is the third
As shown by the arrow 11 in the figure, the polymer passing through the outer periphery of the first filter medium 2 and the second filter medium 8 is allowed to flow into the inside through the ring 9, thereby causing the polymer to flow inside the ring 9. This prevents the formation of stagnation areas.

The leaf filter 7 having the above structure is used in the same way as the conventional leaf filter shown in FIG. It passes through and enters the leaf filter 7. Here, when the polymer passes through the first filter medium 2, mainly foreign substances are removed, and in the second filter medium 8, gel is mainly removed.

In the above embodiment, the second filter medium 8 acts as a support for the first filter medium 2, but a structure may be adopted in which a support such as a perforated plate is interposed between the second filter medium 8 and the wire mesh 3. Moreover, although the above embodiment is a case in which the present invention is applied to a leaf filter, it goes without saying that the present invention is not limited to this case and can be applied to other types of filters.

[Effect of idea]

As is clear from the above description, the present invention consists of a first filter medium made of a sintered metal fiber with a small mesh opening, and a second filter medium made of a sintered metal with a larger average mesh opening than the first filter material. Because of this structure, it is possible to effectively remove foreign substances and gel from the polymer without increasing the filtration pressure too much. Furthermore, the structure is simple, so the filtration device can be made compact and the cost can be reduced. This has the effect that it is possible to

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
3 are partially enlarged sectional views of the leaf filter of FIG. 1 during filtration, and FIG. 4 is a sectional view of a conventional leaf filter. 1, 7... Leaf filter, 2... First filter medium,
3...wire mesh, 8...second filter material.

Claims (1)

[Scope of utility model registration request] A polymer filter comprising a first filter medium made of a sintered metal fiber and a second filter medium made of a sintered metal having a larger average opening than the first filter medium in the flow direction of the polymer to be filtered. Element.