JPS6153011A - Method and apparatus for cooling and conveying strand - Google Patents

Abstract

PURPOSE:To convey a melted strand while keeping it in a quite stabilized posture, by cooling a strand that is being run while it is cooled by running water associated with the running strand. CONSTITUTION:A strand that is moved in a space surrounded by the upper surface of a lower belt 7 and beads 7' is guided between opposed belts 5, 7 together with cooling water (W) supplied via a slit provided between strand guides 2, 3. Since pulleys 4, 4 for driving the upper belt 5 and pulleys 6, 6 for driving the lower belt 7 drives the upper and lower belts 5, 7 at the same surface speed, the strand (S) is moved in the tunnellike space surrounded by the upper surface of a lower belt 7 and the beads 7' proceeds together with the cooling water (W) toward a pair of take-up guide rollers 8. The upper belt 5 is placed to abut against the tops of the beads 7' of the lower belt 7 and is moved at the same speed as that of the lower belt 7, but is driven in a direction opposite to that for the lower belt 7. Thus the strand is conveyed and cooled at the same time by the cooling water (W).

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method in which a large number of strands obtained by continuously extruding a molten polymer in the form of whole strings is cut into pieces after cooling. More specifically, a molten polymer such as a polymer discharged from a reactor, autoclave, or extruder is extruded from a die head having a plurality of nozzles into a gut or strand shape, and then passed through a cooling device that cools and solidifies the strand using cooling water. The present invention relates to a method and apparatus for cooling a strand in a process in which the strand is guided through a suitable guide device to a cutting machine and cut into strip-like chips or pellets.

[Technical background and problems]

As a method for pelletizing a molten polymer such as a polymer discharged from a polymerization machine or an extruder, there are particularly cutting methods,
An appropriate method is selected depending on the combination of cooling methods. For example, there is a method in which the polymer is discharged into a notebook shape from the slit 5, cooled and solidified, and then cut vertically and horizontally into square pellets, a method in which the polymer is discharged into a mold and the cooled and solidified ingot is crushed into square pellets, or a method in which the polymer is crushed in the shape of a notebook after being cooled and solidified; There are methods such as making one cut on the surface of the die underwater, but in general, the strand method is widely used due to its durability, low noise, high speed, etc., and the cooling method for this strand method is usually a water tank. It is used.

Cooling of strands, especially water 111 - The most important requirement for the cooling method used is not only to cool a large number of continuously discharged strands, for example, in a batch method, but also to cool the strands while continuously cooling them. Unless it is cut and guided and conveyed several times, it cannot be used industrially.

An example of such a system that combines cooling and conveyance is as shown in Japanese Patent Publication No. 51-37937, in which the discharged strand is sandwiched between two belts, passed through a cooling bath, and then cut. Method, or Special Publication 1984-1986
As shown in Fig. 958, there is a known method in which the strands are cut after being discharged into a downstream unit in which cooling water is allowed to flow.
For example, JP 49-46586 and JP 57-14861.
A method is known in which the strands are initially glued together to form a band and then fed directly to a cutting machine.

However, with either method, it is necessary to convey a large number of strands in an aligned form, and if the strands are not aligned, the chips may be cut diagonally, have significantly different lengths, or be bent. Alternatively, the shape of the chips may be significantly different, such as those that are broken, making it impossible to obtain uniform chips. Of course, these defective chips cannot be used as recycled products, but it is important for the industry to reduce the number of inferior chips.
Fourthly, what is needed for industrial use is an increase in production. Generally, methods for increasing the production amount of strands include increasing the diameter of the strands and increasing the take-off speed. However, the former method is difficult to adopt because it affects the quality of the chip, especially in the post-processing process where the chip product is used, and the latter method causes problems such as flowing into the cooling bath, diameter fluctuation due to tension unevenness, and cutting, resulting in an extremely unstable posture. becomes.

[Disclosure of prior art]

Patent application filed in 1983 by the same inventor and applicant as the present invention.
In No. 10447, in order to stabilize the running force of the strand in the cooling bath even at high speeds and to obtain all the chips of stomach quality, a so-called primary cooling method was introduced in which cold water was poured onto the strand before it was immersed in the cold water bath. A cooling method and a cooling device have been proposed that combine cooling and so-called secondary cooling in which the strands are cooled by moving them through a stationary cooling bath, and the flow direction and speed of the cooling water are synchronized with the take-up speed of all the strands. , a technical idea in secondary cooling, which is a category of the present invention, is suggested.

[Purpose and outline of the invention]

In the present invention, the molten polymer discharged from a reactor, autoclave, or extruder is extruded in the form of a strand through a guide plate which prevents fusion by flowing cooling water as primary cooling through a nozzle having a large number of nozzles. After cooling, the strands are cooled and solidified.
The object of the present invention is to provide a method and apparatus for cooling and running a strand consisting of a pair of upper and lower belts, which is a method for main cooling with secondary cooling. That is, by using the method and apparatus of the present invention, large-scale production can be achieved by stabilizing the posture of the strand while it is running, making it easy to take out unstable strands at the start, automatically guiding broken strands, and increasing the strand take-up speed. The aim is to

[Structure of the invention]

In the present invention, a pair of upper and lower endless conveyor belts are arranged with a distance of 1'4 approximately equal to the diameter of the running strand, and each pair of conveyor belts runs in opposite directions so that the strand is conveyed in a predetermined direction. Then, cooling water (secondary cooling) is completely filled into the gap formed by the first general conveyance belt pair, and the injected cooling water is applied at approximately the same speed as the first general conveyance belt as the conveyor belt pair travels. The strands are cooled and transported by flowing water and supplying the strands into the flowing water.

The method of the present invention is a cooling method using a strand cut method in which a string-like strand extruded from a die head is all held by opposing upper and lower conveyor belts, and after the strands are completely cooled and solidified, they are guided to a cutting machine and cut into strip-like chips. Therefore, they succeeded in cooling the strands while aligning them in the direction of flow of the cooling water and conveying them simultaneously with the flowing cooling water. When cooling and conveying a strand in a strand cut method, the device of the present invention has a bead-shaped embankment on the outer peripheral surface of both edges of the lower belt of the opposing upper and lower conveyor belts so that the diameter is approximately the same as or slightly higher than the diameter of the strand. The two side belts are arranged so that the outer circumferential surface of the upper belt is in contact with the bead edge of the lower belt, and run as if sandwiched between the upper and lower opposing belts, and the entrance of the gap between the opposing belts is formed. Cooling water is injected into the belt, and as the belt runs, the cooling water runs continuously with the belt, and the strand is supplied to the tunnel-shaped gap between the opposing conveyor belts, which is almost filled with this cooling water. As a result, they were able to transport the strand in a stable position while cooling the entire strand sufficiently.

〔Example〕

First, I will explain the progression of the strands. Figure 1 Beam actor, autoclave or extrusion! Above all, in order to discharge the molten polymer, it is extruded in the form of a strand from a bay with several nozzles, cooled and conveyed, passed through a take-up roll, and sent to an FFR machine, that is, a strand cutter (not shown). 1 is a die head having a large number of nozzles (not shown) in a single row or in multiple rows,
A number of strands S corresponding to the number of nozzles are discharged from the nozzles. Reference numeral 2.5 is a strand guide, and a slit for supplying cooling water W is provided in the middle part of the strand guide. The pellets are fed into a strand cutter (not shown) which uses a rotating blade and a fixed blade to cut the strand into a predetermined length. or converted into chips (hereinafter simply referred to as chips).

As the strand progresses in this way, the upper belt 5 and the lower belt 7, as shown in the A-A arrow diagram in FIG.
The lower belt 7 has beaded edges 7' formed at both ends thereof to prevent the parallel strands S and cooling water W from spilling out from both ends of the belt 7 during movement. Although 15 strands S are shown in Fig. 2, which proceed in parallel, in normal industry, the minimum number of strands S is one depending on the capacity of the extruder, etc., and the capacity of the strand cutter. Sometimes there are as many as 100 pieces. Therefore, the width of the opposing belt is the diameter of the strand,
It is made with a gap such that adjacent strands do not come into contact with each other, and a suitable distance 111iii depending on the number of strands. The strands procured in this manner and proceeding through the space surrounded by the bead 7'' on the surface of the lower belt 7 are as follows:
Since the cooling water W supplied from the slit provided in the strand guide 2.3 is guided between the opposing belts 5.7, the tunnel-shaped gap formed by the bead 7' and the surface of the lower belt is The upper belt 5 is driven by the pulley 4.4 that drives the upper belt 5;
Since the surface speed of the lower full belt 7 is the same, the strand S advances to the pair of take-up guide rollers 8 together with the cooling water W. ”-side belt 5
is installed so as to be in pressure contact with the top surface of the bead 7° of the lower belt 7, so that the speed is the same as the surface speed of the lower belt 7,
driven in the opposite direction. In this way, the cooling water is guided together with the strands into the gap created by the entire 7° bead on the surface of the upper and lower belts 5.7, and cooling and conveyance by the cooling water W are performed at the same time.

The cooling required for the strand before the polymer discharged from the die head is cut by the strand cutter depends on the temperature at the time of polymer discharge, the specific heat of the polymer, the temperature of the cooling water, the capacity of the cooling water, and the time of cutting with the strand cutter. The cooling length d, which is determined by the temperature or hardness of the surface and inner surface of the strands, is determined by the so-called cooling length d, which is the length of the opposing upper and lower bells l, to obtain a predetermined cooling. On the downstream side of the lower belt 7, the water used for cooling leaves the lower belt at the reciprocating point of the pulley 6 and falls downward, and is collected in a cooling water preparation tank (not shown). The water is reused as cooling water at an appropriate temperature through the slits of the strand guide 2.3.

Fourth, such a pair of upper and lower bells H is run at almost the same speed as the strand take-up speed, and the cooling water and the strands are simultaneously fed to the running upstream side of the pair of upper and lower belts, and the water flow accompanying the running of the belts is used. In this method, the running direction of the upper and lower belts is upward, that is, the lower belt 7 in FIG. 1141
Only H can be raised. Upper and lower pair belt and bead 7″
A tunnel-shaped gap is created by the strands, and since the belt runs between the upper and lower belts, the tunnel-shaped gap is almost filled with cooling water along with the strands. According to experiments, it is possible to take a distance Tri with an upward angle of about 20 degrees, but the most preferable distance is the distance between the upper and lower surfaces of the belt, and the lower and lower surfaces of the belt. The tunnel-shaped gap formed by the bead of the side belt is filled with cooling water, and the diameter and number of strands, cooling length of the belt, and belt running ζ are also sufficient.

4, the industrial optimum value of the distance H, that is, the slope of the belt pair, is determined by the take-up speed of the strands, and if the upward slope is too large, the cooling water will not run smoothly.
On the other hand, if the downward slope becomes too large, the cooling water will flow out quickly at the take-up speed of the strands on the downstream side of the belt pair, and the tunnel-shaped gap will not be filled with cooling water. A rising slope within 20° to 20° is most preferred. Of course, it is almost always horizontal or downhill. An embodiment of the apparatus of the present invention that embodies the method of the present invention is shown in FIG.
A large number of nozzles (not shown) are drilled in the die head 1 in a single row or in a diagonal row, and from the nozzles a number of strands S corresponding to the number of nozzles are passed through the strand guides 2 and 6.
is discharged towards. The strand 2.3 has a transverse slit in its middle part, preferably in the -F direction as much as possible, so that cooling water W can be supplied thereto.

The strand guides may be separated like the strand guides 2 and 3 in Fig. 1, or the cooling water W may be supplied from the upper part of the strand guide 6 alone, or there may be no strand guide. Cooling water w'1 may be supplied to the upper part of the supply side end surface of the lower belt 7 from which the strand cutter is taken out at the meshing portion of the upper and lower belts 5 and 7 installed. The single strand guide may be swiveled in the lateral direction or at its tip by a known method to guide the strand at the beginning of the strand discharge. The upper belt 5 is supported by pulleys 4, 4, and as shown in FIG. 5, a chevron portion 9 corresponding to a normal V-shaped belt is joined to the inner surface of the belt to prevent the belt from meandering. It is driven by 4. The lower belt 7 has a V-shaped belt-shaped chevron portion 10 joined to the inner side and is connected to the pulley 6. It is supported by the upper belt 5 and driven in the opposite direction to the upper belt 5. Balls a7' and 7' are joined to both ends of the surface side of the lower belt 7, and the upper belt 5 is attached so that the surface is in contact with the upper surface of the bead 7'7', and the entire length of the upper belt 5 is It is longer than that. On the upstream side, the part where the lower belt 7 protrudes beyond the upper belt 5 is designed to be inserted into the discharged strand, and the part where the lower side 7 on the downstream side protrudes beyond the upper belt 5 is inserted. Depending on the cooling length, it is possible to easily connect a plurality of upper and lower belts. In this way, the strands S and the cooling water W are supplied to the tunnel-shaped gap formed by the surface 7 of the lower belt, the bead 7° and the surface of the upper belt 5, and the belt pair is The strand S is taken up by the guide roller 8 as it runs, and is supported by a distance H adjusting device (not shown) so that the downstream side of the belt pair is higher than the upstream side,
Following the guide roller 8, a step (not shown)
・The strand is guided to the land cutter and cut into chips. In order to be able to wrap and cover the upper belt even when the upper belt's 5-strand strand S has an abnormal radial thickness, it is wider than the width gap of 7''7' at the bead of the lower belt, and the upper and lower Needless to say, both belts are made of endless polyamide fibers and are coated with DEFRON to make them heat resistant.

An example of discharging polyester from a reactor in batch mode using such an example is as follows: Lower belt width: 600 mm, bead height: 4 mm, soil side upper belt width: 650 m
m+, cooling water temperature 65°C1 cooling water flow rate 24m/hour
The circumference length of the lower belt is 5500 mm, and the circumference length of the upper belt is 4800 mm.

With an upward slope of 5 degrees, a 3 mm cutting length tip with 60 strands and a strand take-up speed of 115 m/min, the operation was extremely smooth with a capacity of 4000 kg/hr. Father, the number of nylon strands is 72, 35 cubic meters per hour of cooling water is applied to the belt at 40 degrees to the top and bottom of the first.
Even when the same amount of cooling water was supplied to the second pair of upper and lower belts at 30°C and with an upward slope of 2°, almost the same amount of production was obtained.

[ [Effects of the Invention] In the method of the present invention, the strand extruded from the die head can be run alone in a state where cooling water is stationary, or run between conveyor belts. Since the cooling water itself is conveyed along with the running of the conveyor belt, the molten strand can be conveyed while being cooled in an extremely stable posture, and the take-up speed can be easily adjusted according to the condition of the strand. Since the strand is passed through the minimum tunnel-shaped gap necessary for taking it up, cooling water can be saved and the temperature of the cooling water can be easily controlled. Because of this, the reactor and autoclave barking can be done by changing the position of the strand cutter upward in the relative position of the die head of the extruder and the strand cutter or the chip dryer following the strand cutter. By separating the pair of belts and the take-up guide roller, it becomes easy to install a strand dewatering device between the guide roller and the strand cutter.

The present invention has all the effects of the method of the present invention, and furthermore, since the strand is divided into upper and lower belts for conveying the strand, it is possible to easily deal with problems in the strand condition, and it is possible to use the belt method. Since the strand itself is flexible and can grip the strand sufficiently, even in the event of a malfunction such as when the strand breaks halfway, the strand can be taken up to the take-up guide roller without requiring the entire strand.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an implementation 1j of the method and apparatus of the present invention, FIG. 2 is a cross-sectional view of the upper and lower belts taken along the arrow line A-A in FIG. 1, and FIG. 3 is a cross-sectional view of the upper and lower belts. 0 is an enlarged cross section of the belt with a V-belt-like chevron attached to the R surface. 1 is a die head, S is a strand, 5 is an upper belt, 7 is a lower belt, 7' is a bead, and 8 is a guide roller. Applicant OM Seisakusho Co., Ltd. Procedural amendment (method) December 18, 1980 1 Case description 1981 Patent Application No. 177134 2 Title of invention Strand cooling conveyance method and cooling conveyance device 3 Amendment person case Relationship with Patent applicant address (residence) 12-17-4 Umeda, Kita-ku, Osaka-shi
, Agent address (residence) Name 5. Date of amendment order (shipment date) November 2, 1982
7th 6th, subject of amendment Full text of the specification

Claims (7)

[Claims] (1) A dissolved polymer such as a polymer discharged from a reactor, autoclave, or extruder is extruded into a strand shape from a die head with multiple nozzles, cooled and solidified by a cooling device, and then guided to a cutting machine and cut into strips. In the method of producing chips or pellets, one or more pairs of upper and lower belts are run at approximately the same speed as the string or strands, and cooling water and strings or strings are simultaneously applied to the upstream side of the upper and lower belts. A method for cooling and conveying strands, which is characterized by cooling the strings or strands while running them using a water flow that accompanies the running of the belt. (2) The method for cooling and conveying strands according to claim 1, characterized in that the upper and lower belts run on the downstream side almost horizontally and upwardly upward relative to the upstream side inlet. (3) Extrude the dissolved polymer such as a reactor, autoclave, or extruder into a strand from a die head with multiple nozzles, cool and solidify it in a cooling device, and then guide it to a cutting machine and cut it into strip-like chips. In the method of A strand system characterized in that a pair of upper and lower belts are provided with walls for cooling and retaining on both edges of the lower belt, and the strings or strands are caused to travel by water flow accompanying the running of the upper and lower belts. Cooling conveyance equipment. (4) The cooling and conveying device for strands as set forth in claim 3, characterized in that the pair of upper and lower belts run substantially horizontally or upwardly uphill. (5) The strand cooling and conveying device according to claims 3 to 4, characterized in that the width of the upper belt is wider than the interval between the bead edges at both ends of the lower belt. (6) Claims 3 to 5, characterized in that the upper belt is made shorter than the lower belt, and there are places on both the upstream and downstream sides where the lower belt does not come into contact with the upper belt. Strand cooling conveyance device. (7) The strand cooling and conveying device according to any one of claims 3 to 6, characterized in that a V-shaped belt for preventing meandering is attached to the back side of each of the upper and lower belts.