JP2001353718A - Device for continuously crystallizing polyethylene terephthalate and molding machine for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide both a novel device for continuously crystallizing polyethylene terephthalate, in which crystallizing treatment is continuously enabled, and a novel molding machine for polyethylene terephthalate which is connected to the device for crystallization and continuously enables molding such as injection. SOLUTION: The device for crystallization is equipped with a tank having the introducing port 3 of pellets before crystallization in the upper part, a conical screen separator provided in the inside of the base of the tank, a space formed in the underside of the screen separator, a falling port pipe 8 which is connected to the deep place of the screw separator and takes out the crystallized pellets to the outside of the tank, a plurality of blades 12 for agitation in the longitudinal direction which agitate pellets existing in the upper half part of the tank and being crystallized in the first term while return the pellets to the upper part, a plurality of blades 13 for agitation in the lateral direction which agitate pellets existing in the lower half part of the tank and in the inside of the screen separator and being crystallized in the latter term without returning the pellets to the upper parts, a feeder 17 for supplying hot air into the tank and an exhaust port 19 for evacuating the spent hot air in the inside of the tank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a continuous polyethylene terephthalate crystallization apparatus and a polyethylene terephthalate molding machine.

[0002] The term "continuous" as used in the text is not a phrase indicating the narrow sense of continuous continuity, but preheating,
This includes any temporary stoppage during the molding process such as pressurization and die cutting.

[0003]

2. Description of the Related Art Polyethylene terephthalate is
In the case of performing molding by a molding machine, it is necessary to obtain a molded product using pellets in a crystallized state.

[0004] The molded article thus obtained is pulverized after its use (waste) and reused (recycled) as regenerated pellets. In general, waste materials generated in the factory, such as the runner portion generated in the above, are similarly pulverized and reused as regenerated pellets.

[0005] However, although the regenerated pellets have returned to the uncrystallized state before crystallization at the time of forming the molded article, they are pelletized as they are and provided to the market. ing. This is used for injection molding and blow molding through a hopper dryer.However, when these are used, for example, it often hardens in the hopper dryer and the machine does not operate. However, there is a need to recrystallize them before using them for molding.

[0006] Since recrystallization is technically difficult, the recrystallization has been carried out in a large factory by mass processing using a large apparatus. A molding company that uses only a small amount of this inevitably purchases at a high price and performs molding, or gives up purchasing and does not perform molding.

Therefore, the present inventor thought that even in a molding plant where only a small amount is to be used, recrystallization (of course, crystallization of virgin pellets) could be easily performed by the company itself. A polyethylene terephthalate crystallizer of a molding system type (see Registered Utility Model No. 3050004) is provided which agitates while returning all the pellets existing in the batch tank upward during the crystallization using only the blades.

[0008]

Thereafter, the performance of the conventional batch type polyethylene terephthalate crystallization apparatus is improved, the crystallization processing amount is increased, the crystallization processing time is shortened,
While further research is being conducted to improve the crystallization processing cost, etc., and respond to the demands of the surroundings, if the crystallization processing can be performed continuously, the crystallization apparatus and the injection molding apparatus will be required. I thought that it would be possible to continuously and efficiently carry out crystallization and molding at once,
Further research and development led to the invention of the present invention.

It is a first object of the present invention to provide a novel continuous type polyethylene terephthalate crystallization apparatus capable of continuous crystallization, and to connect and use the continuous type polyethylene terephthalate crystallization apparatus. It is a second object of the present invention to provide a novel polyethylene terephthalate molding machine that can continuously perform molding such as crystallization and injection.

[0010]

In order to achieve the first object, a continuous polyethylene terephthalate crystallization apparatus according to claim 1 is provided so that polyethylene terephthalate pellets can be used for injection molding, blow molding and the like. Regarding a polyethylene terephthalate crystallization apparatus for forming crystallized pellets, a tank having an inlet for pellets before crystallization at the top, a conical screen separator provided in the bottom of the tank, and a screen formed below the screen separator A space, a downcomer pipe that connects the crystallized pellets that are connected deep in the screen separator to the outside of the tank, and a plurality of vertical pipes that agitate while returning the pellets during crystallization existing in the upper half of the tank upward. During late crystallization in the direction stirring blades and in the lower half of the tank and in the screen separator A plurality of lateral stirring blades for stirring without returning the let up, a hot air supply device for supplying hot air into the tank, and an exhaust port for discharging used hot air in the tank. It is something.

According to a second aspect of the present invention, there is provided a polyethylene terephthalate molding machine for injection molding a downflow pipe of crystallized pellets of the continuous polyethylene terephthalate crystallization apparatus according to the first aspect. It is connected to the pellet receiving port of the molding machine body such as the machine body and the blow molding machine body so that the crystallized pellets can be continuously received.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in the figure, a conical bottom cylindrical tank 2 whose entire outer peripheral surface is covered with a heat insulating material 1 is formed. An inlet 3 for mixed pellets of a coagulation-preventing additive such as calcium phosphate and amorphous pellets of polyethylene terephthalate (hereinafter simply referred to as pellets before crystallization) is provided, and the same bottom is provided inside the conical bottom 4 of the tank 2. 4
A slightly shallow conical screen separator 5 is provided to form a conical space 6 between the conical bottom 4 and the screen separator 5 and a master batch for coloring mixed and crystallized at the lower end of the screen separator 5 A down-flow pipe 8 for pellets (hereinafter simply referred to as crystallized pellets) is connected, and crystallized pellets are supplied from the down-flow pipe 8 to a molding machine (not shown). A rotating shaft 10 that is rotated by a stirring motor (not shown) is skewed through the center of the top wall so that the lower end of the rotating shaft 10 reaches near the bottom opening 11 of the screen separator 5, and around the upper half of the rotating shaft 10. The pellets during crystallization mixed in the upper half of the tank 2 and the like (for example, pellets during crystallization) are mixed while returning upward. Plural longitudinal agitating blades 12 of which
In addition, around the lower half of the rotating shaft 10, a pellet during mixing such as a master batch for coloring existing in the lower half of the tank 2 and the screen separator 5 (hereinafter, simply referred to as a pellet during late crystallization). ) Are attached without stirring back, and a plurality of horizontal stirring blades 13 are attached. Further, the outside air sucked in by a blower 14 near the side of the tank 2 is brought into contact with a built-in heater 15 to heat and supply hot air. Hot air supply device 1 with control panel 16
7, a hot air supply port 18 of the hot air supply device 17 is opened in the outer wall of the conical space 6, and a hot air exhaust port 19 (used with a filter) of hot air is provided in the top wall of the tank 2. The continuous polyethylene terephthalate crystallization apparatus 25 is constituted by providing the crystallization apparatus 25. The continuous polyethylene terephthalate crystallization apparatus 25 is disposed above the injection molding machine main body 26, and the crystallization of the crystallization apparatus 25 is performed. The downflow pipe 8 of the formed pellets is directly connected to the pellet receiving port 27 of the injection molding machine main body 26 in a suspended state to form a molding machine 28.

In the drawings, reference numeral 21 denotes a lid for inspection, reference numeral 22 denotes a dust outlet, and reference numeral 23 denotes a pellet gauge window.

In the embodiment described above, first, crystallized pellets prepared beforehand are filled up to a position below the horizontal stirring blades 13 in the tank 2, and the pellets are used by utilizing this.
And the built-in heater 15 is energized and the blower 14 and the stirring blades 12 and 13 are rotated to warm the entire tank 2 while the pellets before crystallization are charged from the charging port 3 and filled. In this state, the temperature is controlled by the control panel 16 of the hot air supply device 17 to continue the stable temperature state based on the data obtained in advance, so that the pellet before crystallization is crystallized and the crystallization is stable. The pellet gauge window 23 confirms that it has become possible to continuously supply the crystallized pellets, and thus the crystallized pellets are continuously obtained at the start, and the crystallized pellets are filled in advance. The pellets are continuously supplied from the downflow pipe 8 to the molding machine main body 25 following the converted pellets, so that the molded articles are used for continuous operation.

When the pelletized masterbatch for coloring is supplied as in the above embodiment, the mixing is averaged, so that it is not necessary to use a tumbler in advance, which is effective for improving the efficiency.

The present invention can be implemented with various modifications without departing from the spirit of the present invention as follows, for example, and the present invention extends to those modified and implemented. Things. The connection between the downflow pipe 8 of the crystallized pellets of the continuous polyethylene terephthalate crystallizer 25 and the pellet receiving port 27 of the injection molding machine main body 26 is not a direct connection as in the above embodiment, but a hopper drier (dehumidification). Drying). -The rotating shaft has a biaxial structure, and the rotation speed of the vertical stirring blade and the rotation speed of the horizontal stirring blade are separately controlled. An opening / closing shutter 29 for forcibly and temporarily stopping the discharge of crystallized pellets is provided at a location of the downcomer pipe, for example, in advance to a location below the horizontal stirring blades 13 in the tank 2. It is easy to use for ensuring the filled state of the crystallized pellets, or to stop the supply of the crystallized pellets before ending the molding operation and empty the molding machine body. In the above example, the pre-crystallization pellets, the pre-crystallization pellets, the late crystallization pellets, and the crystallized pellets are obtained by mixing a pelletizing masterbatch for coloring, an anticoagulant additive such as calcium stearate, and the like. However, it is performed by not mixing, and by appropriately mixing other things.・ The means for feeding and discharging hot air should be implemented with an appropriate configuration such as putting it in from above the tank and taking it out from below.

[0017]

The continuous polyethylene terephthalate crystallization apparatus according to the first aspect is as described above, and thus a pellet before crystallization of polyethylene terephthalate (regenerated pellet), a masterbatch for coloring, calcium stearate and the like are charged. While stirring while sending hot air in this state, the whole does not crystallize instantaneously and becomes rigid in the tank and does not become stuck. Particularly, in the above-mentioned method, the plurality of vertical stirring blades 12 are stirred while returning the pellets during crystallization existing in the upper half of the tank upward while returning the pellets upward. During the crystallization, the pellets are preheated one by one and the lateral stirring blades 13 are placed in the lower half of the tank and in the screen. The preheated condition of the late crystallization pellet lies in the separator was stirred not return upward,
In other words, the pellets during late crystallization after being preheated in the upper half of the tank are cooled by contacting or approaching the pre-crystallization pellets that have just been thrown in from the inlet,
Pre-heated pre-crystallization pellets are prevented from being isolated by the presence of the pellets, and crystallize the latter crystallization pellets more reliably and in a stable and defect-free state. And the crystallization treatment amount can be increased, the crystallization treatment time can be shortened, and the crystallization treatment cost can be reduced. Because the pellets before crystallization are not mixed, there is no problem even if the crystallized pellets are continuously discharged from the downflow pipe, and it is possible to reliably supply them continuously to injection molding machines and other molding machines. This has a remarkable effect that contributes to the provision of the molding machine according to the second aspect.

A polyethylene terephthalate molding machine according to a second aspect of the present invention is a molding machine for a continuous polyethylene terephthalate crystallization apparatus according to the first aspect, wherein a downflow pipe of crystallized pellets is used as an injection molding machine body, a blow molding machine body, or the like. The continuous polyethylene terephthalate crystallization apparatus according to claim 1, wherein the crystallized pellets are connected to the pellet receiving port of the main body so as to be capable of continuously receiving the crystallized pellets. Supply of preformed pellets, and the main body of the injection molding machine is capable of continuously molding a molded article, which significantly improves productivity of the molded article, By using waste materials generated in the factory, such as the runners generated, it is possible to obtain crystallized pellet molded products in the factory. It is intended to achieve the benefits of such so that it is.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment according to claim 1;

FIG. 2 is a sectional view of a main part showing an embodiment according to claim 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulation material 2 Tank 3 Input port 4 Conical bottom 5 Screen separator 6 Space 8 Discharge pipe 10 Rotating shaft 11 Bottom port 12 Vertical stirring blade 13 Horizontal stirring blade 14 Blower 15 Heater 16 Control panel 17 Hot air supply device 18 Hot air supply port 19 Exhaust port 21 Inspection lid 22 Dust removal port 23 Pellet gauge window 25 Continuous polyethylene terephthalate crystallizer 26 Injection molding machine main body 27 Pellet receiving 28 Molding machine 29 Shutter for opening and closing

Claims (2)

[Claims] The present invention relates to a polyethylene terephthalate crystallization apparatus for converting polyethylene terephthalate pellets into crystallized pellets so that the pellets can be used for injection molding, blow molding, and the like. A conical screen separator provided in the bottom of the tank, a space formed below the screen separator, a downflow pipe for discharging crystallized pellets connected to a deep portion of the screen separator out of the tank, A plurality of longitudinal stirring blades for stirring while returning the pellets during crystallization in the upper half upward,
A plurality of lateral stirring blades for stirring without returning the pellets during the late crystallization in the lower half of the tank and in the screen separator without returning upward, a hot air supply device for supplying hot air into the tank, and a tank A continuous type polyethylene terephthalate crystallization apparatus, comprising: an exhaust port for discharging spent hot air from the inside. 2. The downflow pipe of the crystallized pellets of the continuous type polyethylene terephthalate crystallization apparatus according to claim 1 is crystallized at a pellet receiving port of a molding machine body such as an injection molding machine body, a blow molding machine body and the like. A molding machine for polyethylene terephthalate, which is connected in a state capable of continuously receiving finished pellets.