JPH0671734B2 - Melt plasticizer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a melt plasticizing device for thermoplastics applied to an extruder, an injection molding machine, or the like.

(Prior Art) A raw material heating device in a conventional thermoplastic melting and plasticizing device is a batch type in which a packed bed type heating device 1 is provided near the melting and plasticizing device 100 as shown in FIG. The heated resin raw material is transferred to the melt plasticizing apparatus 100.

The heating device 1 has a funnel-shaped perforated plate, which is filled with a resin raw material inside, and which is circulated by a fan 6 and is heated by a heat exchanger 5 through a blowing duct 14 below the filled resin layer 1a. Two
The resin particles are heated by being blown through and passing through between the particles of the filled resin layer.

The hot air that has passed through the filled resin layer is sucked by the fan 6 from the upper part of the heating device 1 and circulates. The hot air temperature is detected by the temperature sensor 7 at the outlet of the heat exchanger 5, and is controlled by controlling the temperature of the heat exchanger 5 by the temperature controller 8.

The resin in the heated heating device 1 opens the valve 3 and
It is discharged to the hopper 101 of the melt plasticizing device 100. The problem with this type of heating device is that it is difficult to make the temperature distribution of the resin particles constant, so that the temperature of the resin discharged from the valve 3 cannot be made constant, and the discharge of the filled resin layer is not possible. Since it is stable and takes a long time, the residence time of the resin raw material may vary. Further, in order to ideally keep the temperature of the resin particles in the filled resin layer constant, heating for a long time is required.

Then, when the heating time was long and the heating temperature was high, the resin particles in the packed bed were viscous, and the whole was solidified in the shape of "sweet" of the candy, causing a problem in processing.

However, supplying the resin raw material as it is through the heating device 1 without directly supplying it to the melt plasticizing device is a very effective means in that the capacity of the melt plasticizing device can be improved by 20 to 30%.

(Problems to be Solved by the Invention) Thus, although it is a useful heating device, in the conventional method as described above, since the heating time in the heating device is long, it is difficult to inline with the melting plasticizing device, Since the temperature cannot be too high, the capacity of the melt plasticizer cannot be as high as expected.

The present invention was developed in order to solve these problems, and the in-line melt plasticization is equipped with a heating device capable of raising the heating temperature in a short heating time while supplying a desired amount of raw material resin. They are also trying to provide a device.

(Means for Solving the Problems) Therefore, in the present invention, in the melting and plasticizing apparatus for thermoplastics, the raw material inlet and outlet of the raw material supply section are crossed, and the air blowing port is provided at the lower part of the apparatus and the upper part is provided. A fluidized bed heating device is provided which is provided with an exhaust port and heats while forming a fluidized bed of a raw material resin. This is also a means for solving the problem.

(Operation) When heated air is blown into the thermoplastic plastic raw material that is supplied from the raw material inlet of the raw material supply section and flows to the outlet from the air inlet at the bottom of the device that is arranged at the inlet and outlet, the plastic raw material floats. As a fluidized bed kept in suspension, it flows toward the outlet, and the heated air is discharged from the upper outlet. And the entire surface area of the raw material is effectively used,
Contact with the fluid is intimate and uniform, and heat exchange is good. Further, since the heating air velocity is not inferior, the heating time is shortened at the same heating temperature, and even if the heating temperature is raised, the resin particles do not stick to each other and smoothly continue to flow.

As this flow means, for example, when the blowing surface of the heated air is inclined, it becomes the flow surface of the resin particles, and while flowing under its own weight, it continues to move from the inlet of the heating device to the outlet direction, to the melting plasticizing device. It enables continuous supply of resin.

(Example) Hereinafter, the Example of this invention is described in full detail based on drawing.

FIG. 1 is a cross-sectional view showing the outline of an embodiment of a melt plasticizing apparatus according to the present invention, which has a fluidized bed heating device for fluidizing a thermoplastic material as a fluidized bed. Reference numeral 10 is a fluidized bed heating device, and a hopper 11 is arranged on the upper part of the device, the hopper 11 has a screw type fixed amount feeder 12, and the fixed amount feeder 12 is driven by a variable speed motor 13. What is a fluidized bed? Iwanami Physics and Chemistry Dictionary, 3rd edition version (Published February 24, 1981)
According to the report, "a layer in which a solid particle is kept in a suspended suspension by blowing up a stream from the bottom of the device. It is in an intermediate state between the fixed bed and the air-transporting phase, and in this state, there is an advantage that a uniform mixture of solid particles and fluid can be handled as a kind of fluid. Since the entire surface area of the particles is effectively used, the contact with the fluid becomes intimate and uniform, heat exchange is good, there is no fear of local heat, and the temperature can be easily adjusted. It is used in various fields including the petroleum industry, gas phase catalytic reaction, laughter, calcination, and drying. ”

The outlet of the fixed quantity feeder 12 is connected to the upper part of the fluidized bed heating tank 17, and the outlet 17a of the fluidized bed heating tank 17 is connected to the melt plasticizer 1
It is connected to the raw material supply port of 00. 18 is a blowing plate, the second
As shown in the figure, a perforated plate, a wire net, etc. are attached to the bottom frame 20, and constitute the bottom part of the fluidized bed heating tank 17 for flowing down the resin particles while blowing them up with hot air. One end of the blowout plate 18 is rotatable by a hinge 19, and the blowout plate 18 can be set at an arbitrary inclination angle. 4 is a suction duct of the fan 6, 40 is an exhaust port provided in the upper part of the fluidized bed heating tank 17, and 14 is the air sent by the fan 6 heated through the heat exchanger 5 and then fed to the fluidized bed heating tank 17. It is a blowing duct for blowing. 7 is a temperature sensor arranged on the downstream side of the heat exchanger 5, and 8 is a temperature controller.

In the above structure, the raw material resin R in the hopper 11 is sent to the fluidized bed heating tank 17 by the fixed amount feeder 12. Quantitative feeder 12
Is driven by the variable speed motor 13, the raw material resin R corresponding to the desired amount is supplied.

The raw material resin that has entered the fluidized-bed heating tank 17 is blown up by the hot air blown from the blow-off plate 18 to form a so-called fluidized bed. Since the blowing plate 18 is inclined downward from the resin inlet to the outlet, the raw material resin R moves to the lower side of the blowing plate 18 by its own weight with time and is supplied to the melt plasticizing device 100 from the outlet 17a. become. The residence time (heating time) of the raw material resin R in the fluidized bed heating tank 17 can be changed by changing the angle of the blowing plate 18.

The hot air blown from the blower plate 18 heats the raw material resin R, is then sucked into the fan 6 via the exhaust port 40 and the duct 4, and is reheated by the heat exchanger 5 and again passes through the blow duct 14 to heat the fluidized bed. Return to tank 17.

The outlet side air temperature of the heat exchanger 5 is measured by the temperature sensor 7, and the temperature controller 8 controls the heat exchanger 5 to maintain a predetermined temperature.

According to the experiment, the area of the blowing plate 18 is 0.4 m ² and the blowing wind speed is 2 m /
s, the required heating time per 10 kg of resin was about 2 minutes.

FIG. 3 shows another embodiment of the fluidized bed heating apparatus. The fluidized bed heating device 10-1 has a multi-stage blowing plate, and the illustrated example shows a case where the blowing plates have three stages of 18a, 18b, and 18c. Each of the blowing plates 18a, 18b, 18c has a hinge 1 at its end.
It can be rotated at 9, and can be set to any inclination angle. The hot air blown from the blowing duct 14 is blown out from the blowing plate 18a at the lowermost stage to fluidize the particles of the raw material resin R to heat and transfer the resin particles. In the next blower plate 18b, the hot air blown from the lowermost blower plate 18a again blows out from the blower plate 18b to fluidize the resin particles in the same manner as in the lowermost blower plate. Also in the uppermost blowing plate 18c, the hot air is sucked from the exhaust port 40 to the fan 6 after forming a fluidized bed for fluidizing the resin particles by the same action.

If the blowing plates of the fluidized bed heating device are multi-tiered as in this embodiment, there is an effect that the installation space of the heating device can be reduced.

FIG. 4 shows still another multi-stage fluidized bed heating device 10-2. A blower box 180 is attached to the upper two blower plates 18b and 18c, and an exhaust port 40 is provided in each of the upper, middle, and lower stages.
a, 40b, 40c are provided, and the flexible hose 180a is configured to positively send hot air to the upper and middle blowing plates 18b, 18c. Upper, middle and lower blower plates 18a, 18b,
The hot air blown from the 18c is exhausted above the exhaust ports 40a, 40
It is sucked by the fan 6 from b and 40c through each duct. The operation and effect are almost the same as those of the fluidized bed heating apparatus 10-1 in FIG. 3, but in the case of this embodiment, the thermal efficiency is further improved.

FIG. 5 shows an example in which a fluidized bed heating device 10 similar to that of the first embodiment is applied to a heating roll type melt plasticizing device 100-1 used for forming a vinyl chloride sheet or a rubber sheet. . Therefore, its function and effect are the same as those of the first embodiment described above.

(Effects of the Invention) As described above in detail, according to the present invention, the thermoplastic raw material is crossed with the raw material inlet and the outlet of the raw material supply section by the preheating device of the melting and plasticizing device of the thermoplastic resin. ,
An air inlet is provided at the bottom of the equipment, and an exhaust outlet is provided at the top so that heating is performed while forming a fluidized bed of raw material resin, so heating is performed from the downward direction that intersects the plastic raw material flowing from the inlet to the outlet. By blowing the air, the entire surface area is effectively used, the contact with the heated air becomes intimate and uniform, and the heating can be performed with high thermal efficiency, and the capacity of the melting device can be greatly improved.

Further, according to the present invention, the supply amount of the raw material resin can be controlled to a desired amount, and the heating device and the melt plasticizing device can be in-line. And when this in-line system also supplies cold or warm resin to a screw-type melt plasticizer, there is a risk of causing abrasion to the screw etc., but by supplying hot resin, the melt plasticizer It is possible to greatly reduce the wear.

[Brief description of drawings]

1 to 5 relate to a melt plasticizing apparatus of the present invention. FIG. 1 is a sectional view showing a schematic configuration of a first embodiment, FIG. 2 is a detailed sectional view of a hot air blowing section of the apparatus, FIG. 3 to 5
FIG. 6 is a sectional view showing a schematic configuration of different embodiments, and FIG. 6 is a schematic sectional view showing a relationship between a conventional melt plasticizing device and a heating device. Description of main parts of the figure 10 …… Fluidized bed heating device 11 …… Hopper 12 …… Fixed amount feeder 18 …… Blowing plate 100 …… Melt plasticizer

Front page continued (72) Inventor Yoshinori Watanabe No. 1 Takamichi, Iwazuka-cho, Nakamura-ku, Nagoya, Aichi Prefecture, Nagoya Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Hideo Tsukamoto Iwatsuka-cho, Nakamura-ku, Nagoya, Aichi No. 1 Mitsubishi Heavy Industries, Ltd. Nagoya Research Laboratory (56) References: 62-15915 (JP, U)

Claims (1)

[Claims] 1. In a melting and plasticizing apparatus for thermoplastics, a raw material inlet and an outlet of a raw material supply section are crossed,
An apparatus for melting and plasticizing a fluidized bed heating apparatus, comprising: an air blowing port provided at a lower portion of the apparatus; an exhaust port provided at an upper portion thereof;