JP2529048B2 - Fine powder remover - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in the process for producing a thermoplastic synthetic fiber melt-spun by a melt extruder, and more specifically to a chip or pellet (hereinafter abbreviated as pellet) which is a raw material for the thermoplastic synthetic fiber. The fine powder removing device.

[0002]

2. Description of the Related Art A pellet, which is a raw material for a thermoplastic synthetic fiber, is pelletized into a sheet cut or a strand cut by a cutter after cooling a molten polymer.
In this cutting process, minute pellets or burrs are usually generated depending on the polymer properties, cooling conditions, and blade shape.

Immediately after being made into pellets, these fine powders are removed to some extent by a vibrating sieve or the like, but it is difficult to remove burrs from the pellets.

In the melt spinning process, the polymer at the time of melting
Since the hydrolysis is spun, it is necessary to reduce the water content. For example, in the case of PET, it is dried to 50 ppm or less, but at the time of dry crystallization, it is necessary to raise the pellet temperature for crystallization to prevent fusion and to stir the pellet at a low speed of about 10 to 15 rpm.

By stirring in this way, the pellets rub against each other, and fine particles are generated due to surface abrasion or burrs are released, and small pieces of pellets are generated. At present, these fine powders are immediately supplied to a melt extruder after being dried and melt-spun.

[0006] Here, since such fine powder has increased crystallinity and viscosity with respect to normal pellets in the drying step, when melted in the extruder, the fine powder cannot be melted and the molten polymer is melted. There is an unmelted part inside. If spinning is performed in this state, the viscosity locally rises, which causes breakage or fluff formation.

[0007]

The present invention solves the problems of the prior art by removing the fine powder generated in the drying process immediately before the extruder and eliminating the unmelted portion in the molten polymer. It is an object of the present invention to provide a fine powder removing device capable of supplying a uniform polymer.

[0008]

That is, the present invention relates to a resin fine powder removing device for an extruder for melting a thermoplastic resin pellet, which is disposed at an upper position of the extruder and is then inserted at a lower part of the extruder.
A container having an outlet is provided, and at least an inner side wall of the container at the lower side of the inlet and an upper side of the outlet is provided with a support plate inclined upward, and each of the support plates is directed upward in the direction opposite to the support plate with respect to the gravity direction. A filter chamber having a filter in which round rod-shaped rod bodies are arranged side by side to the inner wall at intervals smaller than the minimum diameter of pellets so as to cover the inlet and outlet at an angle of 30 ° to 60 °, and the filter chamber is also provided. The fine powder removing device is characterized in that a fine powder outlet connected to the suction means is provided in the lower part of the.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic view showing an embodiment of the present invention, and FIG. 2 is a partially enlarged view of a filter section.

In the figure, reference numeral 1 denotes a dryer, which dries the raw material pellets sent from the previous step and reduces the water content thereof to a predetermined water content. A melt extruder 2 melts and extrudes the raw material pellets and supplies them to the next spinning machine.

Here, in the conventional method, since the dried pellets are directly supplied to the extruder 2, the abrasion powder, burrs and the like of the pellets generated in the dryer 1 are melted while they are present in the pellets. Since such fine powder has a higher degree of crystallinity and viscosity than normal pellets, there is an unmelted portion due to fine powder pellets in the molten polymer, which causes a yarn breakage and a fluff during spinning. I'm running.

Therefore, in the present invention, the following fine powder removing device 3 is provided between the dryer 1 and the extruder 2 at a position above the extruder for removing fine powder in the pellet after drying.

That is, the fine powder removing device 3 is usually composed of a container 30 having a rectangular cross section and having an inlet 32 and an outlet 33 at the top and bottom, but it goes without saying that it may have another shape such as a circle.

The inside of the container 30 is directed downward from one side to the other side at an inlet 3 with an inclination angle α of 30 ° to 60 ° with respect to the direction of gravity.
Round bars 36 having a circular cross section are arranged side by side in a lateral direction so as to hide the inlet 32 beyond the position corresponding to 2. The intervals of the round bars 36 are arranged so that the minimum diameter of the pellet, the minimum length of a polygon or a gap L smaller than the side is formed, and a filter 35 for fine powder is formed.

Each of the round rods 36 is fixed to the upper end of a support plate 37 which projects downward from the round rod 36 and inclines in the opposite direction to the round rod 36 and projects upward from the inner wall 31.
The filter chamber 34 is constituted by the above. At the lower part of the filter chamber 34, an outlet 38 connected to a suction means for sucking fine powder.
Is provided.

Similarly, above the outlet 33, the outlet 3 is also provided.
A filter chamber 34 'having 8'is disposed at a position (opposite side) opposite to that of the inlet side such that the filter chamber 34 on the inlet side overlaps with a majority of the filter chamber 34 at a certain distance.

In the above, as a preferred example, the case where the filter chambers are alternately provided on the opposite side is shown. However, in the case where three or more filter chambers are provided, the filter chambers are provided so that the introduced pellets do not flow directly to the outlet 33. If arranged, the inlets 32 and the outlets 33 do not necessarily have to be covered or alternated.

The inclination angle α of the round bar 36 constituting the filter 35 is set to 30 ° to 60 ° with respect to the direction of gravity, but normally it is preferable to make it about 45 °. If the inclination is less than 30 °, the pellets may stay without flowing down, and if it exceeds 60 °, the proportion of fine powder flowing down together with the pellets is unfavorably large. Further, it is preferable that the diameter of the round bar 36 is as small as possible if there is no problem in strength, and normally, the diameter of the pellet is around the size of the pellet.

In such an apparatus, the pellets whose water content has been lowered to a predetermined value by the dryer 1 are rotary type.
It is discharged by D4. The discharge amount of the rotary feeder 4 is controlled to be the same as the melt extrusion amount of the extruder 4. The pellets discharged from the rotary feeder 4 are put into the fine powder removing device 3.

The pellets put into the fine powder removing device 3 are collided by gravity with a filter 35 constituted by arranging a small-diameter round bar 36 in a slanting shape at a predetermined inclination angle α. The burr and the fine powder adhered are separated by repeating the scattering of No. 1 and are dropped into the filter chamber through the gap L while flowing down along the filter surface.
It is discharged from 3 and supplied to the extruder 2. The fine powder that has fallen through the gap between the filters is effectively taken out by the suction flow that is negatively sucked from the fine powder outlet of the filter chamber.

The outlet suction may be performed by gravity or any other method, but it is preferable to use negative pressure suction because the suction force is effective for separating fine powder from the gap of the filter.

[0022]

As described above, according to the present invention, fine powder and the like in the raw material pellets supplied to the extruder can be removed reliably and efficiently, and a product of excellent quality can be stably obtained. There is a remarkable effect that it becomes possible.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention.

FIG. 2 is a partially enlarged view of the filter portion of FIG.

[Explanation of symbols]

 1 Dryer 2 Extruder 3 Fine powder remover 34 Filter chamber 35 Filter 36 Round bar 37 Support plate

Claims (1)

(57) [Claims] 1. A resin fine powder removing device for an extruder for melting a thermoplastic resin pellet, which comprises a container disposed at an upper position of the extruder and having an inlet and an outlet at a lower portion thereof. Support plates that are inclined upward are provided on the inner side walls below the inlet and above the outlet, and each of the support plates enters in the upward direction opposite to the support plate at an inclination of 30 ° to 60 ° with respect to the gravity direction, and the outlet is A round rod-shaped rod body is formed so as to be covered, and a filter chamber having a filter in which the inner wall is arranged side by side with a gap smaller than the minimum diameter of the pellet is formed, and the fine powder collecting unit connected to the suction means is connected to the lower part of the filter chamber. A fine powder removing device having an outlet.