JP2001322119A - Method and apparatus for drying resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for drying a resin for realizing a uniformity of resin drying. SOLUTION: The apparatus for drying the resin comprises a plurality of heater units (520, 521-52N, 531-53N, 541-54N) installed as means for drying particulate, powder or pellet-like resin (resin pellet 2). In this case, approaching distances between radiating surfaces of the respective units are set to the same or substantially the same. Thus, transfer heats from the units to the resin are made uniform, and hence the uniformity of the resin drying is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin drying method and a resin drying apparatus used for drying a resin before molding.

[0002]

2. Description of the Related Art In resin molding such as injection molding, if water is contained in a pellet-shaped resin as a molding material,
Since molding defects such as color change occur in molded products, drying of resin before molding is indispensable for improving product quality and improving yield. In this resin drying, low-temperature drying in which heating is performed under reduced pressure has been performed to prevent the deterioration of the resin. The technology relating to resin drying includes Japanese Patent Application No. 11-25 / 1999.
No. 1984, "Resin drying apparatus" and the like.

[0003]

When a granular resin is heated and dried in a drying tank, the dried state may be uneven if heat is not applied uniformly to the resin. However, it is difficult to heat the resin by convection in the drying tank under reduced pressure, and it is difficult to uniformly conduct heat to the resin because the resin has low thermal conductivity. And when using a resin whose drying state is not uniform,
It causes deterioration of molding quality such as uneven color and discoloration of the resin.

[0004] Therefore, an object of the present invention is to provide a resin drying method and a resin drying apparatus which realize uniform resin drying.

[0005]

According to the resin drying method and the resin drying apparatus of the present invention, a plurality of heater units (520, 521 to 52N) are used as means for drying a granular, powdery or pelletized resin (resin pellet 2). , 531-53N,
541-54N), the distances between the heat radiating surfaces of the heater units are set to be the same or almost the same, the heat conduction from the heater units to the resin is made uniform, and the resin drying is made uniform. .

[0006] The resin drying method of the present invention according to claim 1 comprises:
A plurality of heater units (520, 521 to 52N, 53
1 to 53N, 541 to 54N), the resin to be dried (resin pellets 2) is brought into contact with each heater unit, and the distance between the heater units is set to be the same or almost the same, and It is characterized by uniform heat conduction to the resin. That is, in order to dry a large amount of resin, a plurality of heater units are installed. However, it is difficult to uniformly heat the resin by conduction heat with a resin having a low thermal conductivity. Therefore, by setting the same or nearly the same distance between the heat dissipating surfaces of the respective heater units, the conduction of heat from the heater units to the resin is made uniform, whereby a large amount of resin is dried.

The resin drying method of the present invention according to claim 2 is
A single or a plurality of radiating fins (84, 86, 88, 132, 1) are attached to a single or a plurality of heaters (82, 82A, 82B).
34, 136, 138 and 140) are attached to constitute the heater unit. That is, the shape of the heater may be any of a bar shape, a plate shape, and a block shape. When drying granular, powdery or pelletized resin, the area of contact with the heater unit is important for increasing the heating efficiency. Therefore, a heat radiation fin is attached to each heater as a means for transmitting the heat generated by the heater to the resin, and the heat radiation area for transmitting the heat generated to the resin through the heat radiation fin is enlarged to achieve efficient heating. .

[0008] The resin drying method of the present invention according to claim 3 comprises:
Plate-shaped heat radiation fins (84, 86, 88, 132, 13) are provided on the rod-shaped heaters (82, 82A, 82B) in the axial direction thereof.
4, 136, 138, 140) are attached to constitute the heater unit. That is, when the heater has a rod shape, by attaching plate-shaped heat radiation fins in the axial direction, it is possible to form a heat transfer space having a certain spread in the axial direction of the heater and in the circumferential direction thereof, which is efficient. Resin heating can be realized.

[0009] The resin drying method of the present invention according to claim 4 comprises:
The resin is in the form of powder, granules or pellets. That is, there are various forms of the resin used for molding.
It defines a resin in the form of granules or pellets. That is,
ADVANTAGE OF THE INVENTION According to the resin drying method of this invention, a large amount of resin can be efficiently and uniformly dried by a single heat treatment of the resin in the form of powder, granules or pellets.

The resin drying method of the present invention according to claim 5 comprises:
The conduction heat distribution can be changed by selectively switching power supply to the heater unit. That is, the distribution density of conductive heat can be increased by arranging the heater units densely. Therefore, if the distribution of conduction heat is changed by selectively switching the power supply mode for each heater unit or each heater unit, it is possible to respond to the situation such as the shape and properties of the resin and the humidity, or to reduce the demand on the molding apparatus side. It is possible to respond to the case where the drying speed is changed in accordance with the condition, and to realize an efficient drying process.

[0011] The resin drying apparatus of the present invention according to claim 6 comprises:
A processing tank (drying processing tank 6) in which the resin to be dried (resin pellets 2) is put into a low pressure state, and a plurality of heater units (520, 521 to 52N, 53) installed in the processing tank
1 to 53 N, 541 to 54 N), and the proximity intervals between the heater units are set to be the same or substantially the same. That is, this resin drying apparatus lowers the pressure of the processing tank loaded with the resin in order to perform vacuum or low pressure drying. This lowering of the pressure lowers the boiling temperature or the evaporation temperature of the moisture adhering to the resin, and promotes the evaporation. That is, the heating temperature of the resin can be reduced by lowering the pressure, and the deterioration of the quality of the resin due to overheating can be prevented.

Then, a plurality of heater units are installed,
By setting the proximity intervals between the units to be the same or substantially the same, the heat conduction between the heater unit and the resin becomes equal, and uniform heating and drying of the resin can be performed.

[0013] The resin drying apparatus of the present invention according to claim 7 comprises:
Power supply means (power supply device 9) for supplying power to the heater unit
4) and switching means (switching circuit 92) for selectively switching power supply to the heater unit from the power supply means. That is, the distribution density of conductive heat can be increased by arranging the heater units densely, so that the heater units are provided with switching means together with power supply means to selectively supply each heater unit or each heater unit. By selectively switching the power supply mode, the distribution of the conduction heat can be changed.
In this way, as described above, it is possible to cope with the situation such as the form and properties of the resin and the humidity, or to cope with the case where the drying speed is changed according to the demand of the molding apparatus, and to improve the resin drying efficiency. Can be achieved.

The resin drying apparatus of the present invention according to claim 8 is
The heater unit is characterized in that the heater unit is positioned at the same or substantially the same interval as the heater unit on the lid (42) of the processing tank, and is detachably attached. That is, since each heater unit is positioned on the lid of the processing tank, the position of each heater unit does not change, uniform heating processing is obtained, and since each heater unit can be attached and detached, maintenance management is easy. It is.

According to a ninth aspect of the present invention, there is provided a resin drying apparatus comprising:
A heater (48) is provided on the outer wall of the processing tank. That is, by heating the resin from inside and outside the treatment tank, efficient and uniform heat treatment can be performed.

[0016]

FIG. 1 shows an embodiment of a resin drying method and a resin drying apparatus according to the present invention. There are various forms of resin for resin molding, such as a granular form, a powder form, and a pellet form. In this embodiment, a resin pellet 2 is used as a molding resin. The resin pellets 2 loaded in the pellet tank 4 are guided from the pellet tank 4 to the drying tank 6 and subjected to a drying process, and then supplied to the injection molding machine 8.

A pipeline 12 extending from the replenishing hopper 10 is inserted into the pellet tank 4, and a blower 18 serving as suction means is provided in the replenishing hopper 10 via a pipeline 16 provided with an on-off valve 14. Are linked. A pipe 20 is connected to the blower 18. An on-off valve 22 is provided in the pipe 20, and an on-off valve 26 is provided in a pipe 24 branched from the pipe 20. Further, a pipe 28 is branched into the pipe 16, and an on-off valve 30 is provided in the pipe 28. With such a configuration, when the on-off valves 22 and 30 are closed and the on-off valves 14 and 26 are opened to drive the blower 18, the air in the supply hopper 10 is discharged to the outside air through the pipelines 16, 20 and 24, The supply hopper 10 is depressurized, and the resin pellets 2 are sucked from the pellet tank 4 through the pipeline 12 into the supply hopper 10 and loaded. The supply hopper 10 is provided with a filter 27 for separating the air and the resin pellets 2 to prevent the drawn resin pellets 2 from flowing out to the pipe 16 side.

A shutter device 32 as an opening / closing means and a resin detection cylinder 34 for detecting the presence or absence of the resin pellet 2 are provided below the supply hopper 10. The shutter device 32 is provided with a shutter plate 36 for opening and closing the bottom of the supply hopper 10, and the shutter plate 36 is opened and closed by a cylinder 38 as a driving unit. A proximity switch 40 is provided in the resin detection cylinder 34 as means for electrically or optically detecting whether or not the resin pellet 2 has been loaded to a predetermined height.

The drying tank 6 is a processing means for drying the resin pellets 2 in a dry state suitable for resin molding. In the processing, the drying tank 6 is hermetically sealed and reduced in pressure, and heated. Heating by means is also used.
Therefore, the pipe 42 is provided on the lid 42 for opening and closing the drying processing tank 6.
A vacuum pump 46, which is a decompression means, is connected via 4. The drying tank 6 has a plurality of heaters 48 on its outer wall as heating means for heating the resin pellets 2.
Are provided, and a temperature sensor 50 for detecting the heating temperature is provided. A plurality of heater units 520, 52 such as ceramic heaters are provided inside the drying tank 6 as heating means for heating the resin pellets 2.
., 52N are positioned and removably mounted on the lid 42 so as to obtain a uniform conduction heat distribution.

A heater unit 520 is hung down on the inner surface side of the lid 42 for opening and closing the drying processing tank 6 with a bracket 54 serving as a support means. A conical stratification forming guide 56 for radially dispersing and stratifying is attached, and a stratification holding guide 58 as stratification holding means for holding the resin pellet 2 is attached to a lower side of the heater unit 520. . The stratification holding guide 58 is a rhombus-shaped conical body having upper and lower surfaces conical. Further, a tapered surface 60 is formed in a mortar shape at the bottom of the drying treatment tank 6, and the resin pellet 2 is guided from the periphery of the stratification holding guide 58 to the discharge port 62 side. That is, the resin pellets 2 supplied from the supply hopper 10 are:
The stratification is performed by the stratification forming guide 56 in the form of being sequentially stacked in the drying treatment tank 6, preventing vertical flow and preventing partial stratification destruction, and when discharging from the drying treatment tank 6, the center of the laminated resin pellets 2 is formed. It is possible to prevent inconveniences such as depressed discharge of a portion, and to discharge sequentially from the lower layer side.

On the bottom side of the drying tank 6, a shutter device 64 as means for opening and closing the discharge port 62 and means for holding the drying tank 6 in an airtight state is provided. In this embodiment, the shutter device 64 is provided. The two shutter plates 66 and 68 are slidably mounted at intervals, and the shutter plate 66 can be selectively opened and closed by a cylinder device 70 and the shutter plate 68 by a cylinder device 72. That is, the shutter plate 6
When the resin pellets 2 and 6 are simultaneously opened, the resin pellet 2 can be discharged from the discharge port 62 of the drying treatment tank 6. However, when the shutter plate 66 is closed during this discharge, the resin pellet 2 is sandwiched between the shutter plates 66. Although the required airtightness may be impaired, if the shutter plate 68 is closed after the resin plate 2 is prevented from falling by the shutter plate 66, the airtightness of the drying tank 6 can be maintained by the shutter plate 68. it can. In other words, the shutter plate 66 has a function as a means for preventing the resin pellets 2 from being discharged, and the shutter plate 68 has a function as a means for maintaining the airtightness of the drying tank 6.

A shutter device 6 is provided below the drying tank 6.
A storage tank 74 is provided through the storage tank 4, and the resin pellet 2 discharged from the drying processing tank 6 can be temporarily retained in the storage tank 74. This storage tank 74 has a pipe 20
The blower 18 is connected to the supply hopper 78 of the injection molding machine 8 via a pipe 76, and the supply hopper 78 is connected to the pipe 28. That is, by closing the on-off valves 14 and 26 and opening the on-off valves 22 and 30, the blower 18 is driven to lower the pressure of the supply hopper 78, and the pressurized air is sent into the storage tank 74 through the pipe 20. Thereby, the resin pellets 2 in the storage tank 74 are supplied to the supply hopper 78 through the pipeline 76. The supply hopper 78 is provided with a filter 79 for separating the air and the resin pellets 2 so that the flowing resin pellets 2 do not enter the pipe 28 side. The supply hopper 78 is provided with a proximity switch 80 as means for detecting the presence or absence of the resin pellet 2.

According to such a configuration, the resin pellets 2 previously loaded in the pellet tank 4 are supplied from the pellet tank 4 to the replenishing hopper 10, and the resin pellets 2 are opened by opening the shutter device 32 so as to be dried. 6
It is led to. The resin pellet 2 is loaded into the drying tank 6 until the proximity of the proximity switch 40 of the resin detection cylinder 34 is detected. Then, the vacuum pump 46 is driven to drive the drying tank 6.
, And the drying tank 6 is evacuated to a predetermined low pressure, that is, evacuated.
0, 521 to 52N to heat the resin pellet 2. Drying of the resin pellets 2 is performed by heating for a predetermined time, the vacuum of the drying processing tank 6 is released, and the shutter device 64 is opened, whereby the dried resin pellets 2 can be dropped into the storage tank 74. Storage tank 7
The resin pellet 2 of No. 4 is supplied to the supply hopper 78 of the injection molding machine 8 together with the pressurized air by the blower 18, and the presence or absence of the supplied resin pellet 2 can be detected by the proximity switch 80, and the injection molding machine 8 is not interrupted. A required amount of resin pellets 2 is supplied, and the resin molding is performed.

As shown in FIG. 2, a heater unit 520 is provided at the center of the drying processing tank 6, and a plurality of heater units 521 to 52N are arranged concentrically around the heater unit 520. The adjacent distances or adjacent distances between the heat radiation surfaces of the heater units 520, 521 to 52N are set to be the same or almost the same. The heater unit 520 includes a heater 82 and a plurality of radiating fins 8 formed of a radiating conductive plate such as an aluminum plate.
4, a plurality of radiation fins 84, for example, six radiation fins 84 are arranged radially at a constant angular interval (for example, at 60-degree intervals) around a heater 82 installed at the center. In the case of this embodiment, the heater units 521 to 52N are composed of 12 sets and are of the same form, and a plurality of heater units are arranged around the heater 82. The heat radiating fin 86 is provided between the fins 84 and the heat fins 86 and two heat radiating fins 88 are provided in the opposite direction to the heat fins 86.

Such heater units 520 to 52N
According to the arrangement mode, since the proximity distances or the proximity distances between the heat radiation surfaces are set to be the same or almost the same, the heater units 520 to 52N are simultaneously supplied with power, as indicated by a two-dot chain line in FIG. , These heater units 520 to 52
A conductive heat distribution 90 with respect to the resin pellet 2 is formed around the N. Here, the conduction heat distribution 90 indicates a range in which the amount of heat necessary for heating each resin pellet 2 can be obtained by the conduction heat. That is, the heater units 520 to 52
Each conduction heat distribution 90 of N covers the entire space in the drying treatment tank 6. As a result, the resin pellets 2 loaded in the drying treatment tank 6 are uniformly heated by the conduction heat distribution 90, and the drying treatment is performed. Is applied.

FIG. 4 shows an electric heat control system of the drying tank 6. Heater 48, heater unit 52
0, a power supply 94 is connected to the heater units 521 to 52N via a switching circuit 92, and a control device 96 is connected to the switching circuit 92 and the power supply 94. The switching circuit 92 supplies power to the heater 48 and also corresponds to the arrangement pattern of the heater units 520 to 52N, and the heater units 520 to 52N to be supplied with power to obtain a desired conduction heat distribution 90 by selecting a power supply target, and a power supply unit. This is a switch for switching an electrical connection with the switch 94. This switch can be configured by a relay or the like. In addition, the power supply device 94 can be configured by a DC power supply, an AC power supply, a pulse power supply, or the like. The control device 96 can be constituted by a sequence control circuit or a program control circuit, and a microcomputer or the like can be used as control means.

With such a configuration, it is possible to form the conduction heat distribution 90 corresponding to various conditions such as the capacity of the drying tank 6 and the shape of the resin pellet 2 to be dried. Power can be supplied to every other one to form the conduction heat distribution 90. As a result, the resin pellets 2 in the drying tank 6 can be uniformly dried without unevenness, and can be efficiently processed.

Next, FIG. 5 shows the structure and disassembly of the drying treatment tank 6. The resin detecting cylinder 34, the shutter device 32, and the replenishing hopper 10 are integrally mounted on the upper surface of the lid 42 of the drying processing tank 6, and the heater unit 520 is fixed to the lower surface of the lid 42 via the bracket 54. In addition, a plurality of heater units 521 to 52N are detachably attached around the heater unit 520. That is, the resin detection cylinder 34, the shutter device 32, the supply hopper 10, the heater unit 520, and the heater units 521 to 52N are integrated with the lid 42 as a supporting member. Further, as illustrated in the heater units 522 and 52N, each heater unit 5
21 to 52N, the top side of the heater 82 penetrates through the lid 42, and the heater 8 is fixed with a fixing screw 98 as fixing means.
2 is fixed on the upper surface side of the lid 42 and hangs down on the lower surface side of the lid 42.

Then, a cylinder device 100 as an elevating means is installed adjacent to the drying tank 6, and a lid 42 is fixed to a plunger 102 connected to a piston of the cylinder device 100 via a bracket 104. .
By connecting the pressurizing source to the cylinder device 100 and increasing or decreasing the pressure, the plunger 102 can be moved up and down as shown by the arrow A, thereby opening and closing the lid 42, and at the same time, simultaneously heating the heater units 520, 521 to 52N. Can be exposed to the outside of the drying tank 6 or can be installed in the drying tank 6. When the lid 42 is opened, various maintenances such as cleaning the inside of the drying tank 6 can be performed. The exposed heater units 520, 5
Cleaning or replacement of 21 to 52N can be performed.

Next, FIG. 6 shows a fixing structure of the lid 42 and the heater units 520, 521 to 52N. A flange portion 106 on which the lid 42 is placed is provided in the opening 105 of the drying tank 6, and a step portion 108 corresponding to the flange portion 106 is provided on the periphery of the lid 42,
An O-ring 110 is provided as a means for maintaining airtightness. A through-hole 112 for charging the resin pellet 2 is formed in the center of the lid 42, and a plurality of brackets 54 are fixed to the lower surface side of the lid 42 with screws 114.

On the upper surface of the lid 42, heaters 82 of the heater units 521 to 52N which penetrate the lid 42 are detachably fixed by fixing means. In this embodiment,
The fixing means of the heater units 521 to 52N is constituted by the fixing plate 116 and the thumb screw 118 instead of the fixing screw 98 shown in FIG. That is, the fixing plate 116 is provided on the upper surface of the lid 42.
The heater units 521 to 52N are detachably fixed together with the fixing plate 116 with the thumb screws 118. A power supply 94 is connected to a power supply terminal 120 protruding from the heater 82 via a switching circuit 92 shown in FIG.

As shown in FIGS. 7 and 8, the heater 82 of each of the heater units 521 to 52N has a conductive pipe such as a sheathed heater or the like in which a lower end is closed and a heating element is sealed inside through an insulator. It is configured with. A fixed ring 122 is attached to the upper end of each heater 82. The fixed ring 122 is made to penetrate the lid 42, and its upper side is projected to the upper surface of the lid 42, and as a fixing and positioning means in the diameter direction of the projected portion. Are formed in parallel with each other. As shown in FIGS. 9 and 10, a U-shaped notch 1 to be engaged with a groove 124 of the fixed ring 122 is provided on a fixed plate 116 for fixing the fixed ring 122 on the upper surface of the lid 42.
28, and a long hole 130 is formed on the central axis of the cutout 128. The notches 128 are engaged with the grooves 124 to position and fix the heaters 82 to prevent rotation and rattling, and to position the heater units 521 to 52N in a predetermined direction. Further, a thumb screw 118 penetrates the long hole 130 and is detachably attached to the lid 42, and the fixing plate 116 is fixed to the lid 42 by the thumb screw 118.

Then, by loosening the thumb screw 118, the fixing plate 116 can be slid according to the length of the long hole 130 as shown by a solid line and a two-dot chain line in FIG. Therefore, this slide allows the fixing plate 11
6 can be engaged with or released from the groove 124 of the fixed ring 122 projecting from the upper surface of the lid 42.
21 to 52N can be attached and detached. As shown in FIG. 11, the heater units 521 to 52N can be positioned and attached to the lid 42 at predetermined positions.
16 has a function as positioning means. In FIG. 11, the heater unit 521 includes the thumb screw 11
8 shows a state in which the fixing plate 116 is retracted and the fixing plate 116 is retracted, that is, a state before fixing.

FIG. 12 shows another embodiment of the form and arrangement of the heater unit. In this embodiment, a plurality of heater units 531 to 53N are installed concentrically between the heater unit 520 and the heater units 521 to 52N shown in FIG.

In the case of this embodiment, the heater unit 53
1 to 53N are composed of 12 sets, and the heater unit 5
The 20 radiation fins 84 are radially arranged at half the arrangement angle of the heat radiation fins 84, that is, at an angular interval of 30 degrees. In this embodiment, a narrow radiating fin 132 is mounted on the heater unit 520 side around the heater 82, and a wide radiating fin 134 is mounted on the opposite side.
2 and 134 are arranged linearly and the radiation fins 134 are arranged between the heater units 521 to 52N, so that the heater units 520, 521 to 52N and 531 to
The proximity distance between the heat radiating surfaces is set to be the same or almost the same with 53N.

With this configuration, the entire heating area can be covered by the heater units 520, 521 to 52N, 531 to 53N with a narrow conduction heat distribution 90 as shown in FIG. It can correspond to the tank 6, and in the same drying processing tank 6, the supply current can be reduced by increasing the density of the heater units 520, 521 to 52N and 531 to 53N.

FIG. 14 shows another embodiment of the form and arrangement of the heater unit. In this embodiment, a plurality of heater units 531 to 53N, 541 to 5N are arranged around the heater unit 520 shown in FIG.
4N are arranged on concentric circles.

In the case of this embodiment, the heater unit 53
1 to 53N, 541 to 54N are composed of 12 sets,
One of the arrangement angles of the radiation fins 84 of the heater unit 520
/ 2, that is, radially arranged at an angular interval of 30 degrees.
The form of the heater units 541 to 54N is such that a plurality of heaters, for example, two heaters 82A and 82B
6 and hold at regular intervals and thermally connected,
A radiating fin 138 toward the heater unit 520 is mounted on the heater 82A side, and a plurality of radiating fins, for example, two radiating fins 140 are formed on the heater 82B side. Further, the heater units 531 to 53N are installed on the heater 82B side, and similarly to the embodiment of FIG. A wide heat radiation fin 134 is formed on the side of each heat radiation fin 13.
4 are radiating fins 140 of the heater units 541 to 54N.
It is arranged between. By arranging the heater units 531 to 53N and 541 to 54N in this manner, the heater units 520, 531 to 53N, 541 to
The close distances between the heat radiating surfaces of the 54N are set to be the same or almost the same.

With this configuration, the entire heating area can be covered by the heater units 520, 531 to 53N, and 541 to 54N with a narrow conduction heat distribution 90 as shown in FIG. In the same drying processing tank 6, the supply current can be reduced by increasing the density of each of the heater units 520, 531 to 53N, and 541 to 54N, and efficient and uniform drying can be performed. Processing can be realized.

[0040]

As described above, according to the resin drying method or the resin drying apparatus of the present invention, the conductive heat of the plurality of heater units can be uniformly applied to the resin, and the heating and drying of the resin can be made uniform. can do. According to the resin drying device of the present invention, since each heater unit is positioned on the lid that opens and closes the processing tank, the position of each heater unit does not change, and uniform resin drying can be achieved. Since each heater unit can be attached and detached, maintenance management can be facilitated.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a resin drying method and a resin drying device of the present invention.

FIG. 2 is a diagram showing an arrangement of heater units.

FIG. 3 is a diagram showing a conduction heat distribution by the heater unit shown in FIG. 2;

FIG. 4 is a block diagram illustrating a power supply control device of a heater and a heater unit.

FIG. 5 is a diagram showing the configuration and disassembly of a resin drying treatment apparatus.

FIG. 6 is a diagram showing a mounting structure of a lid and a heater unit.

FIG. 7 is a diagram showing an outer shape and a mounting structure of the heater unit.

FIG. 8 is a diagram showing an outer shape and a mounting structure of the heater unit.

FIG. 9 is a perspective view showing an engagement relationship between a fixed ring and a fixed plate.

FIG. 10 is a diagram showing a mounting structure of a heater unit.

FIG. 11 is a plan view showing a fixing portion of the heater unit.

FIG. 12 is a view showing another arrangement of the heater unit.

FIG. 13 is a view showing a conduction heat distribution by the heater unit shown in FIG.

FIG. 14 is a diagram showing another arrangement of the heater unit.

FIG. 15 is a view showing a conduction heat distribution by the heater unit shown in FIG.

[Explanation of symbols]

2 Resin pellet (resin) 6 Drying tank 42 Lid 48 Heater 520, 521 to 52N, 531 to 53N, 541 to 5
4N heater units 82, 82A, 82B heaters 84, 86, 88, 132, 134, 136, 138,
140 radiation fin 92 switching circuit (switching means) 94 power supply device (power supply means)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Satoshi Takagi 201 Nishi-Kashiwara Nitta, Fuji City, Shizuoka Prefecture Inside F-term (reference) 3L113 AA01 AB05 AC08 AC16 AC24 AC45 AC46 AC54 AC57 AC63 AC67 AC75 AC83 AC86 BA02 CA04 CA06 CB05 CB16 CB24 CB28 CB31 CB34 DA11 DA24 4F201 AC01 AC04 AK09 AR06 AR07 AR16 BA04 BC01 BC02 BC12 BC19 BD04 BN05 BN27

Claims (9)

[Claims] A plurality of heater units are installed, a resin to be dried is brought into contact with each of the heater units, and the distance between the heater units is set to be equal or substantially equal to each other, so that the heater unit is connected to the resin. A resin drying method characterized in that the heat is made uniform. 2. The resin drying method according to claim 1, wherein said heater unit is constituted by attaching one or a plurality of radiating fins to one or a plurality of heaters. 3. The resin drying method according to claim 1, wherein said heater unit is constituted by attaching plate-shaped heat radiation fins to a rod-shaped heater in an axial direction thereof. 4. The method for drying a resin according to claim 1, wherein said resin is in the form of powder, granules or pellets. 5. The resin drying method according to claim 1, wherein the conduction heat distribution can be changed by switching power supply to the heater unit. 6. A processing tank for lowering the pressure by adding a resin to be dried, and a plurality of heater units installed in the processing tank, wherein the proximity intervals between the heater units are set to be the same or substantially the same. A resin drying device, comprising: 7. The resin drying apparatus according to claim 6, further comprising a power supply unit for supplying power to the heater unit, and a switching unit for selectively switching power supply to the heater unit from the power supply unit. 8. The resin drying apparatus according to claim 6, wherein the heater unit is positioned at the same or substantially the same distance as the heater unit, and is detachably attached to the lid of the processing tank. 9. The resin drying apparatus according to claim 6, wherein a heater is provided on an outer wall of the processing tank.