JPH03249205A - Melt spinning machine - Google Patents

Abstract

PURPOSE:To obtain the subject economical apparatus capable of stably producing a high quality product at a high speed by equipping plural spinning nozzles in the longitudinal direction, fixing a heater to the inside of a rectangular supporting frame thereunder and specifying the ratio of wett density on the surface in the longitudinal direction to that on the edge surface. CONSTITUTION:Plural spinning nozzles 2 are set to a spinning pack 1 attached to a spin block 13 and a shutter 3 capable of preventing yarn-cooling wind sent from a spinning cylinder 9 from ununiformly blowing up in the direction of the spinning nozzles 2 and having a hole 4 for yarn passage at the central part is equipped thereunder. The side surface is equipped with a heating block 6 for making a delayed cooling unit 5 and rectangular supporting frames 81 are attached to the inner periphery side thereof so as to surround the plural spinning nozzles 2 corresponding thereto. A sheathed heater 82 is fixed to the inside of the supporting frame 81 to constitute a heater unit 8 and the ratio of watt density of the heater on the surface in the longitudinal direction to that on the edge surface is set to (10:4) to (10:6), thus obtaining the objective melt spinning machine capable of stable and high-speed spinning of a thermoplastic resin.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a melt-spinning apparatus for thermoplastic synthetic fibers such as nylon and polyester, and more specifically to a melt-spinning apparatus for uniformly heating the atmosphere below the spinneret. be.

(Prior Art) In general, when thermoplastic polymers such as polyamides and polyesters are melt-spun, and in particular when performing high-speed spinning or high-speed spinning and rolling, Japanese Patent Application Laid-Open No. 62-33815 describes how to do this industrially advantageously. As described above, a multi-spindle spinning method is used in which a plurality of spinnerets are arranged in a row in a spin block and a plurality of threads spun from the spinnerets are simultaneously processed in the same spinning tube.

By the way, the region where the molten thread discharged from the nozzle becomes thinner is mainly an area surrounded by a heat insulating plate attached to the bottom surface of the spin block in boat fishing, and the atmospheric temperature of the region and the thinning of the molten thread from the nozzle. It is known that the spinnability and physical properties of the spun yarn are greatly influenced by the temperature of the polymer used.

In addition, in recent years, in the case of high-speed spinning and high degree of polymerization of polymers, in order to maintain spinnability, it is necessary to increase the temperature of the polymer at the time of discharge, the temperature of the atmosphere in the area surrounded by the above-mentioned heat insulating plate, etc. It is essential to prevent the crystallization of the yarn, and for this purpose, a heating cylinder or heater is provided in the area to raise the ambient temperature, and the cap temperature is also increased by convection heat transfer from the area atmosphere or radiant heat transfer from the heater. The temperature of the polymer at the time of discharge is increased by increasing the temperature of the polymer during discharge.

In such a spinning device, the yarn spun from the spinnerets located at both ends is heated from three sides, and therefore tends to have a higher temperature than the yarn located in the middle. For this reason, the physical properties (especially dyeing) of the spun yarns vary widely between spindles, requiring stratified management of products, and products with significant differences in dyeing cannot be shipped as products. There were problems such as complicated management work and a decline in the quality of products.

(Object of the Invention) The present invention has been made to solve such conventional problems, and in particular, it is necessary to install a heating tube or the like in the lower position of the base.
Melt spinning can uniformize the ambient temperature surrounding the yarn when zone heating is performed by installing a heater, and can stably obtain high-quality products with no yarn unevenness between each yarn. The purpose is to provide a device.

<Structure of the Invention> That is, the present invention provides a melt spinning apparatus for thermoplastic synthetic fibers incorporating a plurality of spinnerets in the long-plane direction, in which a plurality of spinnerets are provided at a position below the spinnerets in a manner that corresponds to and surrounds the plurality of spinnerets. A rectangular support frame is provided, a heater is fixed inside the support frame, and the ratio of the watt density of the heater between the longitudinal surface and the end surface is set to 10:2 to 10.8. This is a melt spinning device.

<Example> The present invention will be described below based on the drawings. Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is a sectional view taken along line AA in Fig. 1, and Figs. 3 and 4 are sectional views taken along BB and CC in Fig. 2, respectively. It is a diagram.

In the figure, 1 is a spinning pack attached to a spin block 13, and a spinneret 2 that discharges a plurality of molten polymers.
have.

Reference numeral 3 denotes a shutter for preventing the yarn cooling air from the spinning tube 9 from blowing up unevenly in the direction of the spinnerets 2 and for securing the delayed cooling section 5. It has a yarn passage opening 4 and can be divided at the center so that it can be pulled out left and right. 6 is a heating block for forming the delayed cooling section 5.

The heating block 6 includes a heat retaining (insulating) block 7 having a hollow rectangular shape and a heating heater 8 built into the inner peripheral side of the block.

As shown in FIGS. 2 to 4, the heater 8 is a heating element mainly consisting of a plate-shaped support frame (heat transfer frame) 81 and a sheath heater wound inside the support frame (a sheath heater is preferable, but any other heating element can be used). It consists of a band (not shown) for fixing the sheath heater 82 to the support frame 81 and a temperature detection end 83 for detecting the temperature of the sheath heater 82.

The sheath heater 82 may be one continuous heater, or may be independently adjustable and provided on each side.

Note that the temperature detection end 83 is fixed to the sheath heater 82 by welding.

Reference numeral 10 denotes a cooling air outlet located at the upper part of the spinning tube 9, and has a cooling air outlet (surface) 11 and a cooling chamber 12.

14 is an exhaust hole provided to prevent polymer decomposition gas from remaining under the cap, and 15 is an exhaust hole provided to prevent cooling due to exhaust air.
It is ta.

In such a device, the yarn y discharged from the spinneret 2 passes through the delay cooling section 5 surrounded by the guide shutter 7 and flows into the cooling chamber 12, where it is cooled and solidified by the cooling air blown out from the outlet 11. .

In this case, ascending air currents or descending air currents are mixed in the delayed cooling section, and the atmosphere surrounding the descending yarn does not have a uniform temperature.Moreover, with the conventional surroundings, the temperature is even more uneven. tended to encourage However, the present inventor conducted numerous experiments and analyzes and determined the heating state, that is, the heating rate, of the longitudinal surface (the surface parallel to the downward direction of yarn flow) and the end surface on the side almost perpendicular to this, that is, within a specific range, that is, the heating rate of these heaters. It has been found that if the watt density ratio is set within the range of 10:4 to 10:6, the atmospheric temperature of each weight becomes constant and stable.As a result, in the present invention, the heating block's height is within the above range. It is maintained as such.

The amount of heat generated per unit area on each surface of the heater (support frame) is determined by the length of the surface, , as shown in Figures 3 and 4, and the ratio of the stepped layer width q, , u2 of the sheath heater to L2, cl/L1 and Qz/'L2 can be arbitrarily set by changing the longitudinal surface and the end surface.

Here, as a guide for calculating the watt density of the heater, the watt density of each of the longitudinal surface and end surface is Q, ,Q,
Then, Qt :Q2 = (Wl/SS): (W2/
S2 )=(σ・n,/Ll・H): (σ・nz
/Lz ・H) In addition, S・Area of the support frame σ: Calorific value per unit length of the sheath heater n・Length of the sheath heater on each side of the support frame H: Height of the support frame FIG. 5 is a schematic perspective view of another embodiment. When the sheath heater 82 is installed annularly inside the support frame 81 as shown in the figure, the height of the support frame must be within the above range. The winding density of the nichrome wire 821, which is the heating element of the sheath heater 82, is changed between the longitudinal surface a and the end surface.

Although various methods can be used to control the ambient temperature, a simple method such as measuring an arbitrary point on the sheath heater 82 with the temperature detection end 83 and controlling the temperature to a predetermined temperature using a temperature controller or the like can control the temperature almost uniformly throughout. Temperature is fully controllable.

Although the above example has been described with four spinnerets, it goes without saying that the present invention is not limited to this and can be similarly applied to cases with two to three or five or more spinnerets.

Using a melt spinning (drawing) apparatus as shown in Figures 1 to 4, using a heating block in which the ratio of the watt density of the longitudinal surface and the end surface of the heater was set to 10 = 5, polyester having a relative viscosity of 0.98 was spun. Spinning the chip at a temperature of 295℃ and a spinning speed of 600m.
250 denier/48 filament yarn was obtained by spinning at a drawing speed of 3000 m/min.

In this case, conventional melt spinning (
As a result of comparing the yarn obtained under the same conditions as above using a stretching) device and the difference in dyeing, the conventional example had a score of 1-2 points, while the one according to this example had a marked improvement of 0-4 points. , and the denier fluctuation rate has also become much better than before.

(Effects of the Invention) As explained above, according to the present invention, it is possible to uniformly adjust the temperature of the atmosphere surrounding the falling yarn at the lower position of the spinneret, and it is possible to stably obtain products of excellent quality, especially in high-speed spinning. It becomes possible. Moreover, the device itself does not require a complicated structure and is low cost, which has a great advantage in terms of equipment costs.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing an actual example of the present invention, FIG. 2 is an A-AlIT plane view in FIG. 1, and FIGS. 3 and 4 are B-B and C-C in FIG. 2, respectively. The sectional view and FIG. 5 are schematic perspective views showing another embodiment. 2... Spinneret, 6... Heating block, 8... Heating heater, 9... Spinning section, 81... Support frame , 82...--Sisshiri 1st Figure 1 and Figure 1 Figure

Claims (1)

[Claims] In a thermoplastic synthetic fiber melt-spinning apparatus incorporating a plurality of spinnerets in the longitudinal direction, a rectangular support frame is provided below the spinneret so as to correspond to and surround the plurality of spinnerets, and the support A melt spinning apparatus characterized in that a heater is fixed inside a frame, and the ratio of the watt density of the heater between the longitudinal surface and the end surface is set to 10:4 to 10:6.