JPH04224908A - Method and apparatus for regulating length of cooling of strand - Google Patents

Abstract

PURPOSE:To regulate the length of cooling of a strand by forming in advance a lower conveyor belt into a mesh-like belt with multiple pores and inserting sealing plates from the starting end side of the lower conveyor belt to be provided in parallel with one another so that their total length substantially corresponds to the length of cooling of the strand depending upon a variety of thermoplastic resin. CONSTITUTION:A cooling conveyor section A has endless upper conveyor belts 3A, 3B and also has an endless lower conveyor belt 4. A strand, which has come to the entry part of the cooling conveyor section A, is accompanied with cooling water and conveyed to the exit part of the cooling conveyor section A by the running of the belts. A plurality of first support plates 20 being sealing plates and a plurality of second support plates 21 being water- permeable members are provided in parallel in this order, extending from the starting end side of the lower conveyor belt to the terminal end side thereof, on the lower portion of an upper tightening frame part 4A of the lower conveyor belt 4. The length of cooling can be regulated to a desired length by varying the arrangement condition of the first and second support plates 20, 21 prior to the cooling conveyance of the strand. For example, on the assumption that the length M of cooling is three times as long as the length of the first support plate 20, three plates of the same may be provided in parallel with one another.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention discharges thermoplastic resin in the form of a strand from a die head having a plurality of nozzles, immerses the discharged strand in cooling water, and conveys the strand with the cooling water up and down. The present invention relates to a method and apparatus for adjusting the cooling length of a strand in which the strand is conveyed while being cooled while being held between belts and guided to a cutting machine to form chips.

0002

[Prior Art and Problems to be Solved by the Invention] Strands are made by discharging thermoplastic resin from a die head in the form of a string, and a large number of strands are arranged in a line and are continuously cooled and solidified using an appropriate means. While doing so, it is guided to a cutting machine and cut into chips, which are used as raw materials for synthetic fibers and synthetic resin products. By the way, a typical example of a device that guides a strand discharged from a die head to a cutting machine while cooling and solidifying it is disclosed in Japanese Patent Application Laid-Open No. 189908/1983, and is equipped with a pair of upper and lower belts. The strand is sandwiched between a pair of belts together with cooling water and conveyed while being cooled. By the way, when cooling the strand, it is necessary to cool the strand to a desired cooling temperature for the following reasons.

[0003] If the strand is cooled too much, the strand becomes too hard, and when the strand is cut, it may break or crack, making the cutting process difficult. ■Also, if the strand is cooled too much, the internal temperature of the strand will drop, making it impossible to evaporate and remove the moisture adhering to the surface of the strand while it is being transported to the cutting machine after cooling. . ■On the other hand, if the cooling is insufficient, the strands will not harden sufficiently, so when the strands are cut,
The cut surface may be deformed or so-called whiskers may occur. Also, the chip may be cut diagonally, resulting in a distorted chip shape. Therefore, it is necessary to cool the strand to a predetermined solidified state, and therefore it is necessary to adjust the cooling length of the strand depending on the thermoplastic resin used.

In order to adjust the cooling length of the strands, in the conventional example described above, the belt is replaced with a belt having a length corresponding to the cooling length, or the belt rows are connected in multiple stages. However, in such a conventional example, the cutting machine also needs to be moved, which is time-consuming and troublesome. Therefore, in order to solve the above problem, it may be possible to adjust the conveyance speed of the belt. That is, in the case of a strand with a long cooling length, the transport speed is set to be low, and in the case of a strand with a short cooling length, the transport speed is set to be high. However, when the conveyance speed is made variable in this way, a new problem arises in that the amount of chips produced changes. An object of the present invention is to provide a method and apparatus for adjusting the cooling length of a strand that can solve the above-mentioned problems.

[0005]

[Means for Solving the Problems] In order to solve the above problems, the characteristic configuration of the strand cooling length adjustment method provided by the present invention is to discharge thermoplastic resin in the form of a strand from a die head having a plurality of nozzles. The discharged strand is immersed in cooling water, and the strand with the cooling water is sandwiched between upper and lower conveyor belts, conveyed while cooling, and guided to a cutting machine to form chips. A plurality of sealing plates are prepared in advance, each of which is formed into a mesh shape with a large number of through holes, and which supports the lower conveyor belt and serves as a blind plate. A sealing plate is inserted and arranged in parallel to the lower part of the tensioned rack part from the starting end side of the lower conveyor belt, and the length from the starting end of the upper tensioned part to the final position sealed by the sealing plate is determined by The point is that the cooling length of the strand corresponds roughly to the type of resin.

[0006] In addition to the sealing plate, a plurality of water-permeable members are provided which are capable of discharging the cooling water on the upper rack part and support the upper rack part. A water-permeable member may be inserted and arranged in the remaining part of the sealing plate other than the part where the sealing plate is arranged in parallel. The water-permeable member may be a plate-shaped body in which a plurality of drainage holes for discharging cooling water are formed. Furthermore, the cooling water may be sucked in by a suction device provided between the sealing plate at the final position of the sealing plates and the water-permeable member adjacent to the final sealing plate. Further, the characteristic configuration of the strand cooling length adjustment device provided by the present invention is that thermoplastic resin is discharged in the form of a strand from a die head having a plurality of nozzles, and the discharged strand is immersed in cooling water to cool it. A strand containing water is sandwiched between upper and lower conveyor belts, conveyed while being cooled, and guided to a cutting machine to form chips, wherein the lower conveyor belt is formed in a mesh shape having a large number of through holes,
A plurality of sealing plates, which support the lower conveying belt and serve as blind plates, are removably attached to the lower part of the upper tension portion of the lower conveying belt. In addition to the sealing plate, a water-permeable member capable of discharging the cooling water on the upper rack part and supporting the upper rack part is detachably attached to the lower part of the upper rack part of the lower conveyor belt. Sometimes it is installed. The water-permeable member may be a plate-shaped body in which a plurality of drainage holes for discharging cooling water are formed. Furthermore, a suction device for sucking cooling water may be provided between the sealing plate at the final position of the sealing plates and the water-permeable member adjacent to the final sealing plate.

[0007]

[Operation] According to the present invention, prior to cooling and conveying the strands, a sealing plate is inserted and arranged in parallel to the lower part of the upper tension portion of the lower conveyor belt from the starting end side of the lower conveyor belt. The length from the starting end to the final position sealed by the sealing plate is set to approximately correspond to the cooling length of the strand. As a result, when the strand discharged from the die head is conveyed along with cooling water while being sandwiched between the upper and lower conveyor belts, in the belt portion where the sealing plate is provided,
The cooling water is not drained away, so that the strands are cooled in this belt section. Moreover, since the length of the belt portion is adjusted in advance to approximately correspond to the cooling length of the strand depending on the type of thermoplastic resin used, the strand that has passed through the final sealing plate can be adjusted to the desired length. It becomes a solidified state. Note that the cooling water is discharged from the subsequent water-permeable member. Thereafter, therefore, the strand is guided to the cutting machine at the desired hardness without being cooled.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show a first embodiment of the present invention, FIG. 1 is an overall perspective view of the first embodiment of the present invention, FIG. 2 is an exploded perspective view of main parts, FIG. 3 is a side view of main parts, and FIG. and FIG. 5 are diagrams for explaining the principle of the present invention. First, referring to FIG. 1, numeral 1 denotes a die head, which is connected to a batch type polymerization reactor (not shown). The die head 1 includes a large number of nozzle holes (not shown), and forms a strand row S by discharging molten resin in a string form from each nozzle. Although 20 strands are shown in the figure, it goes without saying that in industry, one to several hundred strands may be formed as needed; for example, a die head may have two rows of 50 strands each. It can also be equipped with a nozzle to form 100 strands.

A chute 2 is provided close to the die head 1, and the strand row S discharged from the die head 1 falls onto the chute 2 and flows out from a cooling water outlet provided on the chute 2. While being cooled by the cooling water, it flows down the chute 2 together with the cooling water and reaches the inlet of the cooling conveyance section A. Die head 1 and chute 2
Since a known technique is adopted, detailed explanation will be omitted.

The cooling conveyance section A includes an endless upper conveyance belt 3
A, 3B, and an endless lower conveyor belt 4. The upper conveyor belt 3A is wound between rollers 5 and 6, the upper conveyor belt 3B is wound between rollers 7 and 8, and the lower conveyor belt 4 is wound between rollers 9 and 10. . low
As the rollers 5 and 6 rotate in the direction of the arrow, the upper conveyor belt 3A is driven to travel in the direction of the arrow, and as the rollers 7 and 8 rotate in the direction of the arrow, the upper conveyor belt 3B is driven to travel in the direction of the arrow. By the rotation of the rollers 9 and 10 in the direction of the arrow, the lower conveyor belt 4 is driven to run in the direction of the arrow.

Due to the running of the belts 3A, 3B, and 4, the strands that have reached the inlet of the cooling conveyance section A are conveyed to the outlet of the cooling conveyance section A together with cooling water. During this conveyance, the strand is cooled and solidified to a desired hardness before being guided between the feed rollers 11 and 12. Further, the strand passes between feed rollers 11 and 12 and is guided to a cutting machine 15 consisting of a fixed blade 13 and a rotary cutter 14, where it is cut into a predetermined length to form chips 16.

Next, the configuration of the strand cooling mechanism in the cooling conveyance section A will be explained in detail with reference to FIGS. 2 and 3. The lower conveyor belt 4 is formed into a mesh shape having a large number of through holes 17, as shown in FIG. A plurality of first support plates 20, which are sealing plates, and a plurality of second support plates 21, which are water-permeable members, are arranged at the lower part of the upper tension portion 4A of the lower conveyor belt 4 from the starting end side of the belt. These support plates 20 are arranged in parallel in this order over the terminal side.
, 21 horizontally support the upper frame portion 4A. Therefore, when the strand passes over the top rack portion 4A, the top rack portion 4A does not bend, and therefore the strand is conveyed in a straight state without waving.

[0013] Furthermore, the first and second support plates 20 and 21 are
It is supported by a support member (not shown) and is detachable. Therefore, the first and second support plates 2
0 and 21 as appropriate, the first support plate 20
and the second support plate 21 can be arranged side by side in a desired arrangement. In this embodiment, the first support plate 20 and the second support plate 21 have the same size, and a plurality of each are prepared in advance. As shown in FIG. 2, the first support plate 20 has a large number of drainage holes 22 formed therein for discharging cooling water, and the second support plate 21 has drainage holes 22 formed therein.
It is said to be a so-called blind plate in which no Therefore, in the area where the first support plate 20 is arranged in the upper tension portion 4A of the lower conveyor belt 4, the through hole 17 is sealed by the first support plate 20, so that the cooling water is discharged. The cooling state of the strands is maintained by the cooling water. On the other hand, in the upper tension section 4A of the lower conveyor belt 4, the second
In the region where the support plate 21 is arranged, the strands are not cooled because the cooling water is discharged through the through holes 17 and the drainage holes 22.

By the way, when cooling the strands, in order to improve the quality of the chips, it is necessary to match the cooling temperature of the strands to the thermoplastic resin used, so it is necessary to adjust the cooling length of the strands according to the thermoplastic resin. arise. In such a case, in the present invention, the desired cooling length can be adjusted by changing the arrangement of the first and second support plates 20, 21 in advance before cooling and transporting the strand. For example, the cooling length M (see FIG. 4) of the thermoplastic resin used in this example is the width m (see FIG. 4) of the first support plate 20.
(see), the cooling length M can be obtained by arranging three first support plates 20 in parallel. Therefore, in the example shown in FIGS. 1 and 2, as shown in FIG. are installed in parallel.

When the cooling length M of the thermoplastic resin used is smaller than the case shown in FIG.
When the width is twice the width m, the cooling length M of the thermoplastic resin to be used can be obtained by arranging two first support plates 20 in parallel. Therefore, as shown in FIG.
The two first support plates 20 extend from the starting end to the terminal end.
and three second support plates 21 are arranged in parallel. In this way, a plurality of first support plates 20 and second support plates 21 are prepared in advance, and prior to cooling and conveying the strands,
A cooling length corresponding to the thermoplastic resin used can be obtained by a simple operation of changing the arrangement of the first and second support plates 17 and 18.

For reference, in this example,
Although the second support plate 21 is used as the water-permeable member, a support roller may be used as the water-permeable member. That is, support rollers may be arranged at intervals below the upper tension portion 4A of the lower conveyor belt 4 to discharge the cooling water. However, when the support roller is used in this way, the support roller must be moved when adjusting the cooling length, making the operation extremely troublesome. Regarding this point, in this embodiment, it is only necessary to insert and remove the support plate and replace it, and the operability is significantly excellent.

FIG. 6 is a simplified perspective view showing the main structure of a second embodiment of the present invention. In this second embodiment, a suction device 30 is provided between the last first support plate 20 and the first second support plate 21 adjacent thereto. As a result, the amount of cooling water discharged from the drainage hole of the second support plate 21 can be reduced, so the drainage efficiency of cooling water can be improved, and the cooling and solidification state of the strands can be determined with higher accuracy. can be realized. In the first and second embodiments described above, the first support plate 20 and the second support plate 21 have the same shape, but if a large number of plates with different widths are prepared, Furthermore, it becomes possible to adjust the cooling length over multiple stages. Furthermore, although the first and second supporting plates 20 and 21 are used in the first and second embodiments, they are hard enough to prevent the lower conveyor belt 4 from bending when the strands pass through. If so, the second support plate 21 may be omitted. Even in this case, the cooling length of the strand can be made variable and the strand can be conveyed in a straight state.

[0018]

[Effects of the Invention] As explained above, according to the present invention, the cooling length can be adjusted by a simple operation in a device in which the strand is conveyed for a cooling length using an upper and lower conveyor belt system, and the belt length is constant. , and can be realized with a simple structure. Therefore, it is possible to obtain a cooling length that corresponds to the thermoplastic resin used, and subsequent processing such as cutting the strands can be performed smoothly.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of essential parts of the first embodiment of the present invention.

FIG. 3 is a side view of essential parts of the first embodiment of the present invention.

FIG. 4 is a diagram showing the arrangement of first and second support plates according to the first embodiment of the present invention.

FIG. 5 is a diagram showing the arrangement of first and second support plates according to the first embodiment of the present invention.

FIG. 6 is a perspective view showing a simplified configuration of main parts of a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1...Die head, 3A, 3B...Upper conveyor belt, 4...Lower conveyor belt, 4A...Upper tension portion of lower conveyor belt, 15...Cutter, 16...Chip, 17...Through hole, 20...First support plate (sealing plate), 21... second support plate (water permeable member), 22...
Drainage hole, A... Cooling conveyance section, M... Cooling length, m... Width length of the first support plate 20, S... Strand row.

Claims (8)

[Claims] Claim 1: A thermoplastic resin is discharged in the form of a strand from a die head having a plurality of nozzles, the discharged strand is immersed in cooling water, and the strand with the cooling water is sandwiched between upper and lower conveyor belts. In the device in which chips are formed by conveying while cooling and leading to a cutting machine, the lower conveyor belt is formed in advance into a mesh shape having a large number of through holes, and supports the lower conveyor belt and serves as a blind plate. Prepare a plurality of sealing plates, and before cooling and transporting the strands, insert the sealing plates in parallel from the starting end side of the lower conveyor belt to the lower part of the upper stretching part of the lower conveying belt, and place them in parallel at the starting end of the upper stretching part. A method for adjusting the cooling length of a strand, characterized in that the length from the strand to the final position sealed by a sealing plate approximately corresponds to the cooling length of the strand depending on the type of thermoplastic resin used. 2. In addition to the sealing plate, a plurality of water-permeable members capable of discharging the cooling water on the upper rack part and supporting the upper rack part are provided, and a plurality of water permeable members are provided at the bottom of the upper rack part. 2. The method for adjusting the cooling length of a strand according to claim 1, wherein a water-permeable member is inserted and arranged in the remaining part of the sealing plate other than the part where the sealing plate is arranged in parallel. 3. The method for adjusting the cooling length of a strand according to claim 2, wherein the water-permeable member is a plate-shaped member having a plurality of drainage holes formed therein for discharging cooling water. 4. A sealing plate in the final position of the sealing plates;
Claim 2, wherein the cooling water is sucked by a suction device provided between the final sealing plate and the water-permeable member adjacent to the final sealing plate.
Or the method for adjusting the cooling length of a strand according to 3. 5. A thermoplastic resin is discharged in the form of a strand from a die head having a plurality of nozzles, the discharged strand is immersed in cooling water, and the strand with the cooling water is sandwiched between upper and lower conveyor belts. The lower conveying belt is formed into a mesh shape having a large number of through holes, in the device which is conveyed while being cooled and guided to a cutting machine to form chips;
A strand cooling length adjustment device characterized in that a plurality of sealing plates that support the lower conveyor belt and serve as blind plates are removably attached to the lower part of the upper tension portion of the lower conveyor belt. . 6. In addition to the sealing plate, a water-permeable member capable of discharging cooling water on the upper rack portion and supporting the upper rack portion is provided at a lower portion of the upper rack portion of the lower conveyor belt. To,
The strand cooling length adjustment mounting according to claim 5, wherein the strand is detachably mounted. 7. The strand cooling length adjustment attachment according to claim 6, wherein the water-permeable member is a plate-like member having a plurality of drainage holes formed therein for discharging cooling water. 8. A sealing plate in the final position of the sealing plates;
8. The strand cooling length adjusting device according to claim 6, further comprising a suction device for sucking the cooling water between the final sealing plate and the water-permeable member adjacent to the final sealing plate.