JP2510858B2 - Die for melt blow - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a melt-blowing die, and in particular, it comprises a capillary tube and an orifice formed around it, and a fiber immediately after extruding a thermoplastic resin from the capillary tube in a molten state is an orifice. The present invention relates to a melt-blowing die that is stretched by a gas blown from the substrate and is made into a finer grain.

Prior art dies using capillaries are known. Japanese Patent Publication 58-4447
The same can be seen in No. 0 and JP-A-56-159336.
In the former Japanese Examined Patent Publication No.58-4470, capillaries are arranged side by side in the die tip with a triangular cross section, and each capillary is soldered, and there is appropriate clearance above and below the die tip. One side of each of the capillaries provided with the gas plate and those arranged in the lateral direction is firmly held by a die block and supported in a cantilever shape, and the tips of the gas plates provided above and below it are suitable for the free ends of the capillaries. The gap between the gas plate and the die tip or between the free end of the capillary and the gas in the molten state immediately after being extruded from the capillary is determined by the clearance between the gas plate and the die free end. It is sprayed and stretched at an angle. The latter JP-A-56-
In No. 159336, the capillaries arranged in a lattice on the nozzle plate are inserted into the mesh holes of the screen so that the tips of the caps project, and gas is blown out from the clearance around the capillaries inserted into the mesh holes. It is shown to draw more extruded fibers. In any case, the above-mentioned clearance around the capillaries should be kept uniform in the direction in which the capillaries are arranged, and the gas should be blown out uniformly everywhere. This is because if the amount of gas blown out changes, the quality of the fibers will vary. Therefore, in the former case, strict precision is required for processing of the gas plate and the tip of the die in order to make the clearance uniform. Clearance may be affected by this. Moreover, in the case where the capillaries are supported by the die block in a cantilever manner, the tips of the capillaries are likely to be misaligned, and there is a risk of vibration when the gas is blown out. Even in the latter case, it is not easy to uniformly form the mesh holes of the screen, and it is also difficult to insert a large number of capillaries into the mesh holes of the screen one by one at a small pitch. There is.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention aims to provide a melt-blowing die which has a uniform clearance around a capillary tube and is easy to manufacture.

According to the present invention, therefore, one end of each of the die blocks having the passage of the molten thermoplastic material is firmly held in the die block in a state of being aligned on the plane, and each of them communicates with the passage. Forming a gas chamber between the plurality of capillaries and the die block combined with the die block, and sandwiching the other end of the capillaries with a flat pressing surface of a lip portion forming a slit communicating with the gas chamber. And a gas plate that holds the gas firmly, and the gas supplied to the gas chamber is blown out from the clearance formed between the adjacent capillary tube and the pressing surface of the lip portion. .

The term "thermoplastic substance" as used herein refers to a thermoplastic resin, which may include a dye, an additive or a modifier added thereto.

Capillaries usually have an inner diameter of 0, 1 to 1 mm and an outer diameter of 0,
The thing of about 2 to 2 mm is used.

The tip of the capillary may also project beyond the tip of the lip, but is preferably retracted inward by 0.2 mm or more.
When the tip of the capillary sticks out from the tip of the lip, the gas blown out from the clearance between the capillary and the lip is diffused again when it leaves the tip of the capillary. It is expected that the stretching function will decrease due to the above, whereas when the capillary tip is retracted inward from the lip tip, a gas with a high flow velocity immediately after being blown out from the clearance can be applied to the fiber. Because it will be.

It is desirable that the pressing surface of the lip be formed with a width of 1 mm or more.

The die may be a single die having a single row of capillaries, or may be a single die having a plurality of rows of capillaries.

Example FIG. 1 shows a spinning apparatus using a melt-blowing die 1 according to the present invention. A thermoplastic resin is melt-kneaded by an extruder 2 and extruded from a capillary tube 3 of the melt-blowing die 1 immediately after extrusion. The fiber 4 is drawn by a gas blown from a clearance 5 (see FIG. 4) formed around the capillary tube 3 and wound around the collecting device 6 in a web shape.

As shown in detail in FIG. 2, the melt-blowing die 1 has a plurality of capillaries 3 in addition to the capillaries 3 arranged in a lateral direction so as to be in contact with each other, and one end of each end is clamped from above and below to firmly support it. Die blocks 7, 7 and lip portion 8
In, the other end of the capillary tube 3 is sandwiched from above and below, and it has gas plates 9 and 9 that firmly support it. The die block 7 is formed with a passage 11 communicating with the capillary tube 3, and the melted state is introduced into the passage. The thermoplastic resin of is extruded from the capillary tube 3. A gas chamber 12 is formed between the gas plate 9 and the die block 7, and a gas pipe 13 shown in FIG. 1 is connected to the gas chamber 12 so that gas is introduced from a gas inlet 14. The lip portion 8 of the gas plate 9 is a capillary tube 3.
The pressing surface of is a flat surface as shown in Figs.
The clearance 5 is formed by the adjacent capillary tube 3 and the pressing surface of the lip portion 8. The gas introduced into the gas chamber is blown out from the clearance 5.
Note that the capillary tube 3 is attached with its tip retracted from the tip of the lip portion by an appropriate amount for the reason described above (see FIG. 2).

Although the melt-blowing die in which the capillaries 3 are arranged in one row is shown in the above embodiment, a plurality of capillaries 3 may be provided if necessary. FIG. 5 shows an example thereof, which has a structure in which the melt-blowing dies 1 of the above-mentioned embodiment are integrally provided on the upper and lower sides, and the gas chambers are introduced into the upper and lower gas chambers 12 from the central gas inlet 14. With this structure, the chamber 11 is formed in a fork shape.

As described above, the melt-blowing die of the present invention firmly supports the other end of the capillary tube whose one end is firmly held by the die block by sandwiching the other end of the capillary plate with the flat lip portion of the gas plate. The gas is blown out from the clearance formed between the capillary tube and the pressing surface of the lip section.If a capillary tube with a uniform diameter is sandwiched by flat surfaces, each clearance will be uniform, so the capillary tube is sandwiched by the lip section. You can easily and surely obtain a melt-blowing die with uniform clearance just by wearing it, and the pressing surface is in contact with the capillary even if the pressing surface is not flat due to processing error, thermal strain, distortion with time, etc. As long as it is possible to maintain each clearance substantially evenly, the capillary is firmly supported at the tip, so it vibrates when the gas blows out and the outlet is It is also possible to obtain a non-woven fabric with a narrow yarn diameter distribution and a good appearance and texture, and to reduce the gas flow passage area so that the gas consumption can be reduced. Have.

[Brief description of drawings]

FIG. 1 is a perspective view of a spinning device by the melt blow method, and FIG.
FIG. 3 is a vertical cross-sectional view of a melt-blowing die, FIG. 3 is a side view of the same, FIG. 4 is an enlarged view of a main part of FIG. 3, and FIG. 5 is a vertical cross-sectional view of another embodiment. 1 ... Melt blow die, 3 ... Capillary tube 7 ... Die block, 8 ... Lip part 9 ... Gas plate, 12 ... Gas chamber

Claims (3)

(57) [Claims] 1. A die block having a molten thermoplastic material passage, a plurality of capillaries, each end of which is firmly held by the die block in a state of being arranged on a plane, and which are in communication with the passage. A gas plate that forms a gas chamber with the die block, and the other end of the capillary tube is firmly held by sandwiching the other end of the capillary tube with the flat pressing surface of the lip that forms the slit communicating with the gas chamber. The melt blowing die is characterized in that the gas supplied to the gas chamber is blown out from the clearance formed by the adjacent capillaries and the pressing surface of the lip portion. 2. The melt-blowing die according to claim 1, wherein the other end of the capillary tube is retracted into the lip portion from the tip of the lip. 3. The melt-blowing die according to claim 1, wherein a plurality of dies are integrated and a plurality of capillaries are provided in a row.