JPH0729298B2 - Resin strand cutting device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a device for cutting a large number of continuously discharged polymer strands into chips.

[Prior Art] Generally, when manufacturing synthetic fibers such as nylon and polyester, so-called chips, which are obtained by molding these polymers into a square, columnar or spherical shape, are used. As such a chip manufacturing apparatus, an apparatus is used in which a molten polymer is extruded in a strand shape and cooled to be solidified or shredded to obtain chips before solidification.

This type of device causes a molten resin in the form of a strand extruded from a discharge hole to flow down along with a cooling water along a chute surface inclined downward, cools and solidifies while applying tension to the strand, and then cuts it into chips. (For example, JP-A-51-115558 and JP-B-55-1167).

Extrusion and cutting work of the resin strands using this kind of device proceed with the extrusion pressure applied in the reaction tank and the cutting speed suitable for this. As the work progresses, the liquid level of the molten resin in the reaction tank gradually decreases, and finally, a state in which several strands are broken occurs.
In the conventional resin chip manufacturing apparatus, when the operator visually observes the strand break, the start button of the end treatment process is pushed to start the end treatment process.

[Problems to be Solved by the Invention] In an apparatus in which an operator presses a start button for starting an end treatment process when a strand break is visually detected as in the above-mentioned conventional apparatus, the start timing of this end treatment process Is not constant, and various problems may occur.

For example, if the start timing of the end treatment process is too early,
The resin remains in the tank and chips cannot be formed, resulting in poor yield. Further, it is also necessary to remove the residual resin. Also,
On the contrary, when the start timing of the end treatment process is delayed, the resin cut off from the bottom of the reaction tank scatters in the vicinity, deteriorating the working environment.

[Means for Solving the Problems] A resin strand cutting device of the present invention is attached to a device for introducing a pressurized gas into a reaction tank to push out a plurality of resin strands from the bottom of the reaction tank. In the cutting device for cutting the chip into chips, a means for detecting a gas ejection sound generated from the bottom of the reaction tank is provided, and when the gas ejection sound is detected, the ending processing step of the cutting device is started. It is characterized by.

The strand-shaped strip will be referred to as a strand hereinafter.

[Operation] In a strand cutter device for chopping resin strands continuously extruded from a large number of pores into chip shapes by pressurizing a reaction vessel containing molten resin, at the end of the extrusion process, the reaction vessel The liquid level of the molten resin inside drops, and comes out when the pressurized gas in the tank directly blows out from the resin discharge hole. In the present invention, a sound wave (for example, an ultrasonic wave) generated at this time is detected, and a signal for starting the end processing step is output as the cutting operation end timing when the sound wave continues for a predetermined time.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view showing an apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view showing a main portion of the apparatus with a part thereof broken, and FIG. 3 is an enlarged view of the main portion of FIG. 2 and FIG. FIG. 4 is a side view of FIG.

As shown in FIG. 1, a die head 1 is provided at the bottom of the reaction tank T, and chutes 5, 8 and 9 for guiding the strands S are arranged below the die head 1, and a cutting device is provided at the lower end thereof. 18 are arranged.

Next, the main structure of this device will be described in detail with reference to FIGS.

2 to 4, a die head 1 made of a molten polymer such as polyester or nylon is provided with ejection holes 2 arranged in two rows in a staggered manner. Reference numeral 3 denotes a chip forming device disposed below the die head 1, and the ejection holes 2 of the die head 1 are provided.
The downwardly inclined chute portion 4 for cooling and solidifying the strand S extruded from the solidified strand S
It is composed of a cutting device 18 for shredding.

The chute part 4 is arranged from above from the first chute 5 and the second chute 5, respectively.
A plurality of guide grooves 12 that are configured to include a chute 8 and a third chute 9, and that guide the strands S to uniformly form a cooling water film in these chutes 5, 8 and 9 are arranged in parallel downwardly. It is provided.

The first chute 5 and the third chute 9 are provided with friction running portions 6 and 10 whose lower portions are curved or bent so that the strand S can reliably run in the guide groove 12 and which comes into contact with the strand S. The first and third chutes 5, 9 are supported by rod bodies 7, 11 so as to be rotatable in the front-rear direction. 13 and 14 are side plates of the chute section 4. Reference numeral 15 is a cooling water supply chamber, and a slit-shaped discharge port 16 is formed in the upper part of the cooling water supply chamber so as to uniformly overflow onto the first chute 5. Reference numeral 17 is an inlet for cooling water.

Reference numeral 5a indicates a guide groove entrance portion.

The cutting device 18 includes a pair of feed rollers 21 composed of rotary rollers 19 and 20 for applying a tension to the strand S just below the third chute 9, and a fixed blade 22 and a rotary blade 23 arranged below the feed rollers 21.
Consists of a shredder cutter 24 consisting of
Cooling water is supplied from an upper discharge port 26 of a water chamber 25 provided on the side (rear side) of 23 to cool the shredded chips C and form a sealed form for sending to the next separator. There is. 27 is an inlet for cooling water. Reference numeral 28 denotes a cooling water sprinkling pipe arranged above the chute portion 4.

Reference numeral 30 is a flap for aligning the strands. The flap 30 uniformly floats the uniform water film flowing out from the cooling water discharge port 16, and its upper side is attached to the side plate 13 by the pivot rod 31 or an arm (not shown) of a link mechanism, and the lower side is a chute. It is provided so that it can be separated from the chute surface of No. 5. An air cylinder 32 is connected to the back surface of the flap 30 or both sides of the flap 30 via link mechanisms (not shown) in order to make the flap 30 move up and down.

As shown in FIGS. 1 and 2, a sensor 40 for detecting a sound wave (for example, an ultrasonic wave) generated from the die head 1 at the end of the extrusion process is installed, and a detection signal of the sensor 40 is transmitted via a signal line 41. Input to the control unit 42. A signal line 43 is output from the control unit 42 for outputting a signal for starting the end processing step.

In the apparatus configured as described above, when starting the chipping work, the chipping apparatus 3 is moved from a predetermined position (in general, the chipping apparatus 3 is provided on a moving body such as a carriage). After the strand S of polyester or the like extruded from the discharge hole 2 of 1 is stopped at a position where it can run while being inclined downward along the chute portion 4,
The required cooling water is kept discharged from the cooling water discharge ports 16 and 26, the sprinkler pipe 28, etc., and the first chute 5 is rotated to the rear side so that the space between the first chute 5 and the second chute 8 is almost the same. An opening for polymer discharge is formed immediately below the discharge hole 2.

Next, a pressurized gas such as nitrogen (for example, 2 to 5 atm) is introduced into the reaction tank T, and the molten polymer is extruded in a strand form from the ejection hole 2 of the die head 1, but the molten polymer ejected first is deteriorated. Therefore, it is discharged to the above opening for a predetermined time and separated as waste polymer. Next, the first shoot 5
To the original position, and the chute S discharged at the same time
The cutting device 1 receives the cooling water from the chute 5 and overflows and drops it, and then the cutting device 1 cuts off the second and third chutes 8 and 9.
Send to 8 and shred. When the strands S are fed into the cutting device 18, tension is applied, and the strands S receive a predetermined draft and solidify to have an appropriate cross-sectional shape and reach a steady state, but in this case, all the strands S correspond to the corresponding chute. Two strands S overlap each other and flow down into one guide groove 12 which is not in the guide groove 12, especially the guide groove 12 of the first chute 5, and when left in this state, chips such as chips and miscut chips fused to each other Bad chips are coming in.
In particular, since the molten resin has plasticity at the start of operation, the strands are fused to each other,
Contains 3 strands.

In order to remove such an incorrect sequence of the strand S,
(Or, in order to make the discharge hole and the guide groove correspond)
The air cylinder 32 is activated to raise the flap 30 so that the lower end of the flap 30 is separated from the chute surface of the chute 5. (Stand up from the state of FIG. 2 to the state of FIG. 3.) Then, the strands S are separated one by one at regular intervals.

That is, by erecting the lower end side of the flap 30 so that the strand S, which is being solidified by the tension, is lifted from the guide groove 12 of the first chute 5 (it is not always necessary to lift it completely from the guide groove 12). , The overlapping upper strands S may be movable.) Since the strands S are under tension, the strands S should be kept at almost the same position as the distance between the discharge holes 2 so that the tension on the flap 30 is minimized. It will move and will be parallel in a straight line. After that, when the flaps 30 are rotated to return to their original positions, the strands S enter the corresponding guide grooves 12 while maintaining the parallel state while the flaps 30 are returning, and are completely separated from the guide grooves 12. It will flow down.

Therefore, after this operation, a defective product such as a fused chip or a miscut chip does not occur, and a chip C having a constant quality and shape can be stably obtained. In the state where the flap 30 is erected, the water film flowing down the chute surface of the first chute 5 is discharged into the air from the lower end edge of the flap 5 while maintaining the water film state, and is swung on the strand S. While falling, it falls on the chute surface of the second chute 8 again,
It flows down along the second chute 8. Therefore, the flap
Even in the state in which 30 is erected, the strands S are always in contact with the cooling water, so that mutual fusion is more reliably prevented.

When the chip production is continued, the liquid level of the molten resin in the reaction tank T gradually decreases. Then, finally, the gas comes to be ejected from some of the ejection holes 2. An ultrasonic wave is generated by this gas ejection, and this ultrasonic wave is detected by the sensor 40. When the ultrasonic wave detection continues for a predetermined time or more, the control unit outputs a start signal of the end processing step, and the end processing step is started. By this end treatment step, introduction of the pressurized gas into the reaction tank T is stopped, cooling water is stopped, and the cutting device 18 is stopped.

[Advantages of the Invention] As described above, according to the present invention, the start timing of the end processing step is optimized. Therefore, the amount of residual resin in the reaction tank is reduced and the yield is improved. Further, since the resin is less scattered at the end of the cutting work, the deterioration of the working environment can be reduced. Further, according to the present invention, the end treatment process can be automatically started, so that labor can be saved.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an embodiment of the present invention, FIG. 2 is a perspective sectional view of an essential part, FIG. 3 is an enlarged view of the essential part, and FIG. 4 is a side view of FIG. 1 ... Die head, 2 ... Discharge hole, 5 ... First shoot, 8 ...
Second chute, 12 ... Guide groove, 21 ... Cutting device, 30 ... Flap, 32 ... Air cylinder, S ... Strand, T ... Reaction tank.

Claims (1)

[Claims] 1. A cutting device, which is attached to a device for introducing a pressurized gas into a reaction tank to extrude a plurality of resin strands from the bottom of the reaction tank, and cuts the strands into chips. A device for cutting a resin strand, characterized in that a means for detecting a gas ejection sound generated from a bottom portion is provided, and when the gas ejection sound is detected, a finishing process step of the cutting device is started.