JPH0534733Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a bag filter that has excellent durability in filter function, excellent recyclability, and is highly chemical resistant.

[Prior Art] Conventional bag filters are known to be made of relatively strong synthetic fibers such as polyamide fibers and polyester fibers, or glass fibers.

[Problems to be Solved by the Invention] Bag filters made of these fibers have the disadvantage of being easily clogged, increasing ventilation resistance, and losing their function.

In order to solve this problem, methods such as applying mechanical vibrations or shocks to the bag filter continuously or intermittently have been adopted, but it is difficult to eliminate the dust deposits by such means. It is necessary to apply a strong mechanical action, and the bag filter is easily damaged, significantly reducing its durability.

Bag filters have stable dust collection properties regardless of whether they are old or new, and do not increase ventilation resistance.
It is required to have a continuous filter function.

The present invention was achieved by investigating the fact that polytetrafluoroethylene fibers as the constituent fibers of bag filters satisfy the above requirements and also significantly improve the conventional drawbacks.

This invention is based on polytetrafluoroethylene fiber.
By being composed of 100%, we were able to provide a highly durable bug filter that has extremely low clogging and excellent collection efficiency, and can easily remove deposits with light mechanical vibration or impact. It is something.

[Means for Solving the Problems] That is, the present invention adopts the following configuration in order to achieve the above object. That is, the bag filter of the present invention is characterized in that it is composed of a bag-like article made by sewing a cloth-like article made of 100% polytetrafluoroethylene fibers with sewing thread made of 100% polytetrafluoroethylene fibers. It is.

The present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view of a bag filter according to the present invention. Bag filter means a bag filter that normally separates and collects particulate matter through dry filtration.

The bag filter 1 shown in FIG. 1 is made by sewing a PTFE fiber fabric 2 into a bag shape using a PTFE fiber sewing thread 3.

The polytetrafluoroethylene (hereinafter simply referred to as PTFE) fiber used in this invention is a tetrafluoroethylene homopolymer or 90 mol% of the total
The above refers to fibers made of a copolymer, preferably 95 mol% or more of which is tetrafluoroethylene.

Monomers that can be copolymerized with tetrafluoroethylene include vinyl fluoride compounds such as trifluoroethylene, trifluorochloroethylene, tetrafluoropropylene, and hexafluoropropylene, as well as vinyl compounds such as propylene, ethylene, isobutylene, styrene, and acrylonitrile. Examples include, but are not limited to, compounds.

Among such monomers, it is preferable to select vinyl fluoride compounds, particularly compounds with a high fluorine content, from the viewpoint of fiber properties.

The average single fiber fineness of the PTFE fiber used in the present invention is preferably as small as possible, but it is 10 d or less, preferably 7 d or less, further 3.5 d or less, particularly preferably 1 d or less.

Among such PTFE fibers, the small-angle X-ray scattering intensity at 2θ = 1° measured by small-angle X-ray scattering was as low as 80 cps or less, and it was measured by wide-angle X-ray diffraction (counter method) (110). A thick material with a crystal size of 95 Å or more is preferable because it has excellent strength and dimensional stability. More preferably, among such fibers, strength is 1.0 g/d or more, elongation is 30% or less,
It is preferable to select a well-balanced material with a dry heat shrinkage rate (230°C x 30') of 20% or less.

The method for manufacturing the PTFE fiber used in this invention includes, for example, using viscose and PTFE as the spinning dope.
Using a mixed solution with the disk version, this is discharged into a coagulation bath, solidified, and then washed and refined with water. After scouring, soak it in alkaline water and squeeze it, then dry it, or
The film is directly introduced into the firing process, fired at 300 to 450°C, and stretched at least 5 to 10 times. Next, this fired fiber is oxidized and aged in a high temperature atmosphere of 300 to 340°C to form a PTFE fiber.

The fabric mentioned in the present invention is a monofilament yarn or a multifilament yarn (which may be untwisted or twisted and bundled) made of 100% PTFE fiber and PTFE fiber obtained as described above. It may also be made of spun yarn, etc.).

Examples of the fabric 2 include non-woven fabrics, knitted fabrics, and composite fabrics thereof, preferably knitted fabrics, and especially woven fabrics as an essential requirement.

The mesh size of the fabric 2 may be arbitrarily selected depending on the size of the particles and dust to be removed, but it is preferable that the mesh size of the fabric 2 does not change and particles and dust can easily fall off. selected.

Preferable textile structures include plain weave, twill weave, and warp knit structures include half, reverse half, woven, and atlas.

As the single fiber fineness of the PTFE fiber used becomes thicker, the fiber becomes rigid and difficult to handle in spinning, weaving, weaving, and it becomes difficult to obtain a fine-grained fabric, so select a thin single fiber with a diameter of 10 d or less. The finer the single fiber fineness, the softer the fabric and the higher its dust collection function.

The PTFE fiber used in the present invention has the characteristic that dust collection deposits can easily and easily fall off due to vibration or impact.

In the present invention, a fabric 2 made of such PTFE fibers is sewn with the PTFE fiber sewing thread 3.

By composing the sewing thread 3 with a material made of 100% PTFE fiber, it has stable cleanliness by making both the dust collection release property and chemical resistance properties the same as the filter part. This provides a bag filter that can be subjected to various cleaning treatments, such as chemical (solvent) cleaning. Since it has the same mold releasability as the bag portion, no dust deposits remain, and stable filter characteristics can be exhibited at all times.

The attachment string 4 is used to attach the bag filter 1 to a predetermined location, and the fiber material constituting it does not need to be particularly limited. However, for the same reason as sewing thread 3, this attachment string 4 is also made of PTFE-based fibers.
It is preferable to use 100% material from the viewpoint of chemical resistance and dust collection releasability.

Furthermore, if the bag-like object has an open end,
Although any shape is acceptable, a cylindrical shape is selected because of its filter function.

In this invention, all the members that make up the bag filter are made of 100% PTFE fiber.
The bag section, sewing section, and other parts are not easily clogged, can be kept clean at all times, and the removal of collected dust deposits is simple and easy, and the filter as a whole can be kept clean. It is.

The baggage filter of this invention is made of PTFE, for example.
PTFE fiber non-woven fabric, PTFE fiber cotton (both PTFE
100% fiber) can be used in combination.

[Effects of the invention] This invention has the characteristics of stable dust collection, easy removal of collected dust deposits, no mechanical damage, and durable maintenance of filter function. Moreover, it exhibits the ideal effect of minimizing the increase in ventilation resistance when using the filter.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of a bag filter according to the present invention. In the diagram, 1...Bag filter, 2...PTFE
3... Sewing thread, 4... Attachment string.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) The product is characterized by being composed of a bag-like article made by sewing a cloth-like article made of 100% polytetrafluoroethylene fiber with sewing thread made of 100% polytetrafluoroethylene fiber. Buzz filter. (2) The bag filter according to claim 1, wherein the polytetrafluoroethylene fiber has a single fiber fineness of 10 d or less. (3) The bag filter according to claim (1), wherein the bag-like article is a tubular knitted fabric.