JPH03213550A - Apparatus for producing pitch fiber - Google Patents

Abstract

PURPOSE:To guide a pitch fiber flow along the right direction by passing air through a specific channel in a die before blasting through a spinning nozzle and straightening the air flow in a direction same as the extrusion direction of raw material pitch. CONSTITUTION:Hot air introduced into the main body 26 of a die from a hot air blasting tube 31 is sent through a cylindrical cavity 33 and blasted from a blasting tube 34 to the upper surface of the front and rear grooves 41 of an air lip plate 28. Hot air passed over a ridge 40 is flowed down along the outer surface of the inclined bottom face of the nozzle main body 27 and blasted from a spinning nozzle 39 in a state to surround a pitch fiber extruded from the tip of a spinning nozzle 27a.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an apparatus for producing pitch fibers by a melt blowing method using coal or petroleum pitch as raw materials.

(Prior technology) Coal or petroleum pitch with a high softening point is heated and molten and extruded through a number of spinning nozzles, and a high-speed gas is blown thereto to form the raw material pitch into a fiber stream consisting of a large number of fine fibers. A device that collects these on a moving collection surface is known (for example, Japanese Patent Laid-Open No. 62-90320).

(Problem to be solved by the invention) In this case, the mechanism for blowing high-speed gas (usually air) onto the raw material pitch extruded from a number of spinning nozzles in a heated and molten state is an air chamber connected to a hot air blowing pipe. The tip of each spinning nozzle faces into an oval or slit-shaped spinning hole provided in the bottom plate, and this structure allows air to flow from the spinning hole along the extrusion direction of the raw material pitch extruded from the spinning nozzle in the form of a thread. is starting to gush out.

However, this ejected air is just a filling gas until it leaves the spinning hole, and it is a turbulent flow with no directionality, so even after it is ejected from the spinning hole, the pitch of the raw material pushed out from the spinning nozzle is accurately guided. The effect is not sufficient.

(Means for Solving the Problems) In contrast, the present invention makes the air to be ejected from the spinning hole ejected in advance in the direction along the extrusion direction of the raw material pitch within the die body, and The inner surface of the part is formed into a wavy curved surface to raise and lower the air flow so that it is rectified in the same direction as the extrusion direction of the raw material pitch before it is ejected from the spinning hole.

(Embodiments of the Invention) In explaining embodiments of the invention with reference to the drawings, first, the outline of the entire apparatus will be explained according to the order in which raw materials are processed. In the general view of FIG. After the raw material is heated to a molten state by the extruder 1, it is sent to a spinning die 25 via a gear pump 24 and is spun downward from a spinning nozzle. At the same time, the fibers are wrapped in heated air introduced from the hot air blowing pipe 31 and are drawn and thinned to form a large number of pitch fibers arranged in horizontal rows on the net conveyor 4 of the fiber collection mechanism 42.
3 to form a web.

Hereinafter, the mechanism of each part will be explained in detail. In FIG. 2, 1 is an extruder, which is constructed by inserting a series of screw shafts 4 across a cylinder 2 and a bearing stand 3 connected to the cylinder 2. A plurality of cylindrical heaters 6 are wound around the outer peripheral surface of the cylinder 2 surrounding the screw portion 5 of the screw shaft 4, and keep the raw material supplied from the hopper 7 in a molten state at all times.

The hopper 7 is made as a closed body with a closed top, and has a raw material supply cap 8 and a peephole 9 on the top, and
Vacuum ports 10 and 11 are provided on the top surface and below the cone, and a heater 12 and temperature sensors 4 and 13 are provided on the circumferential surface of the cylindrical portion. The lower end of this hopper 7 is connected to an inclined cylinder 15 via an opening/closing cock 14, and this inclined cylinder 15
The lower end of the cylinder 2 is connected to the lower end of a short tube-shaped raw material pushing cylinder 16 which is installed upright at the base end of the cylinder 2 in advance.

The upper end of the raw material pushing cylinder 16 is sealed with a cap, and a feed spiral 17 is installed vertically inside the cylinder 2 to constantly force feed the raw material flowing down through the inclined cylinder 15 into the cylinder 2. 18. In addition, 19 is a heater wrapped around the inclined cylinder 15, 20 is a thermocouple holder fixed to the cylinder 2, 21 is a pered pitch decoupling cylinder that communicates with the inside of the cylinder 2, and 22 is attached to one end of the screw shaft 4. This is a sprocket wheel driven by a deceleration motor 23 provided on the stand.

Now, the molten raw material extruded from the tip of the cylinder 2 of the extruder 1 is passed through the gear pump 24 to the spinning die 25.
sent to. This spinning die 25 is shown in FIGS.
As is clear from the figure and the internal explanatory view of FIG.
The nozzle body 27 has a large number of spinning nozzles 27a that are fitted and fixed to the lower surface of the nozzle body 27, and the upper surface of the nozzle body 27 is arranged at a predetermined interval at a predetermined distance. are housed in one casing.

As is clear from FIGS. 3, 5, and 6, the die body 26 is covered with heaters 29 on its circumference and upper surface, and has a molten raw material inlet 30 in the center of the upper surface.
, has two hot air blowing pipes 31 on each of the front and rear surfaces, and the raw material is introduced into the nozzle body 27 in a distributed manner through a slit-shaped portion 32 extending in the left-right direction below the raw material inlet 30. On the other hand, the heated air blown from the hot air blowing pipes 31... enters the cylindrical cavity 33, 33, and is directed downward through the blowing pipes 34... provided tangentially to this cavity. In this way, the molten raw material flows into the central recess 35 of the nozzle body 27, and the heated air flows into the peripheral hole 3 of the nozzle body 27.
6. Enter.

At the bottom of the central concave portion 35 of the nozzle body 27, a large number of spinning nozzles 27a... are connected to the air clip plate 28 at their lower ends.
300 meshes, 2
A filter 37 formed by overlapping two wire meshes of 00 mesh and a breaker with small holes arranged in vertical rows.
A plate 38 is fitted.

The air lip plate 28 is made to have a wave-like cross section, and the spinning hole 3 in which each tip of the spinning nozzle 27a is located is located in the central trough of the air lip plate 28.
9... are provided in the - row, and the front and rear valleys 4 are provided on both sides of this central valley through low ridges 40, 40, respectively.
1.41 is provided, and the heated air blown into the die body 26 passes through the peripheral hole 36 of the nozzle body 27 and is blown onto the upper surface of the front and rear valley portions 41, 41. It passes over the ridges 40, 40, enters the spinning hole 39, and exits downward.

In this way, filamentous pitch is continuously spun from the tip of each spinning nozzle 27a, and these pitch fibers are collected by the fiber collection mechanism 42 shown in FIG. 1 and made into a mat shape of a predetermined width. A guide tube 44 having a rectangular cross section is vertically provided between the upper surface of the net conveyor 43 and the lower surface of the air lip plate 28.

The guide tube 44 is a housing tube with a square cross section, and is formed by detachably connecting four rectangular tubes 45 as shown in FIGS. 1 and 7. The square tube is fixed to the base using brackets 46 and 46. Air blowing pipes 48 and 48 with slit-shaped nozzles 47 transparently provided on the lower surface are installed horizontally in the front and back on the upper end edge, and although not shown, air flow meters, air adjustment valves, and pressure reducing valves are installed at appropriate locations. is attached. The lower end of this guide cylinder 44 is provided at a height of about 35 mm from the upper surface of the net conveyor 43.

As is clear from FIG. 1, the net conveyor 43 is a stainless steel endless net plate of 3 mm square stretched in a triangular shape when viewed from the side, and has a guiding tube located close to the lower surface of the belt surface on the feeding side. An air intake duct 49 is provided directly below the guide tube 44, and an auxiliary air intake duct 50 is also provided below the front of the guide tube, and a cleaning air supply duct 51 and a cleaning air intake duct 52 are provided opposite to each other across the return side belt surface from above and below. . Further, a cover 53 is provided above the feeding belt to cover the upper part and both sides of the part between the guide tube 44 and the belt tip.

In addition, in the figure, 54 is a deceleration motor for moving this net conveyor 43.

(Effect of the invention) With the above configuration, as shown by the arrow in FIG.
In this invention, the heated air introduced into the die body through the hot air blowing pipe 31 first enters the horizontal cylindrical cavity 33.33,
A blowout pipe 34 that extends tangentially downward along the inner circumferential surface of the
..., onto the upper surface of the front and rear troughs 41, 41 of the air lip plate 28, reversely rise and pass over the ridges 40, 40, and then downward along the outer surface of the inclined bottom of the nozzle body 27 to form the spinning hole 39. ... acts to surround the pitch fibers emitted from the tip of the spinning nozzle a... In other words, this heated air repeatedly flows in the vertical direction before being discharged from the spinning hole 39. Therefore, the flow is rectified along the direction in which the pitch fibers flow, and the pitch fiber flow can always be guided in the correct direction.

[Brief explanation of drawings]

The drawings show an embodiment of the invention, and FIG. 1 is an overall side view;
FIG. 2 is an 8-section side view of a part of the extruder and hopper, FIGS. 3 to 6 show a spinning die, FIG. 3 is a plan view of the spinning die, and FIG. 4 is a partially sectional front view. FIG. 5 is a cross-sectional side view, FIG. 6 is an exploded explanatory perspective view, and FIG. 7 is a perspective view of the guide tube as seen from the front.

Claims (1)

[Claims] (1) An extruder that heats the supplied pitch raw material and sends it in a molten state to a spinning die, and a die that turns the fed raw material into a large number of threads through a spinning nozzle and simultaneously blows heated air to create a fiber stream. The spinning die includes a main body and a fiber collection mechanism that collects the fiber flow on a net conveyor and assembles it into a mat shape. A die body is provided with a horizontal cylindrical cavity for storing heated air, and a blowout pipe provided downwardly from the cavity in a tangential direction, and further below the die body, the die body is provided at intervals and surrounds a spinning nozzle on the plate surface. The upper surface of the air lip plate is located directly below the blowing pipe, and the upper surface of the air lip plate is sandwiched between a central trough having the spinning holes and the central trough via a ridge. A pitch fiber manufacturing device characterized in that the pitch fiber is formed into a wavy surface consisting of front and rear troughs.