JPH09254901A - Powder mixer for disposable body warmer and body warmer manufacturing device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a disposable body warmer having desired heat generation performance while suppressing oxidation by mixing two or more kinds of powder including iron powder and water holding agent which are materials for the body warmer while avoiding their contact with air. SOLUTION: A mixer comprises a first tank 5 for receiving iron powder, a second tank 6 for receiving at least water holding agent, a weighing/projecting device, a mixing cylinder 4 formed with a first supply port 10 and a second supply port 11 on an upper part and formed with an exhaust port 12 at a lower part, a mixing screw 7 rotatably provided in the mixing cylinder 4 having the maximum width smaller than an inner diameter of the mixing cylinder 4, a motor 8 for rotation-driving the mixing screw 7 and a shutter 9 provided at the exhaust port 12 of the mixing cylinder 4 so that it can be freely opened/ closed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder mixing device for disposable body warmers and a disposable body warmer manufacturing apparatus using the same. More specifically, by mixing two or more kinds of powder such as iron powder and a water retention agent, which are raw materials for disposable body warmers, while avoiding contact with air, the oxidation reaction is suppressed and a body warmer having a desired heat generation performance is produced. The present invention relates to a powder mixing device for a disposable body warmer, which does not cause dust to be scattered, and does not cause powder clumping, and a disposable body warmer manufacturing apparatus using the same.

[0002] In this specification, the term "powder" is a concept including fine particles, coarse particles, and mixtures thereof.

[0003]

2. Description of the Related Art Conventionally, as a technique for mixing and filling two or more kinds of powder such as iron powder which is a raw material of a disposable body warmer and a water retention agent (oxidizer), for example, two or more kinds of powder and water are used. After adding a predetermined amount to a mixing tank etc. and mixing, transfer it to another container, store it for a certain period of time depending on the case, and then transfer it to the discharge position for filling and fill it in a bag etc. Things are common.

For example, a powder mixing device which has been conventionally used is a twin-screw mixer having two rotating shafts provided with stirring blades, and a ribbon type mixing device having a rotating shaft provided with a ribbon (helical band blade). And a V-type mixer with a stirring blade. The powder and water are mixed by these powder mixing devices, and then the mixed powder is transferred to the hopper of the packaging mechanism main body by a transfer means such as a belt conveyor, and then the powder is mixed by the packaging mechanism main body. A disposable body warmer is made by continuously packing in a breathable bag.

[0005]

However, two or more kinds of powders such as iron powder, which is a raw material for disposable body warmers, and a water retention agent, react when mixed in the presence of air (oxygen). The body needs to be mixed while minimizing the oxidation reaction or filled with nitrogen gas or the like. In this case, with the conventional technique in which the time from mixing to filling is long, the reaction of the powder due to mixing cannot be sufficiently suppressed, and it is not possible to produce a body warmer having a desired exothermic performance. It reduces the commercial value of products that use powder. Further, a special device is required to fill the nitrogen gas, which leads to an increase in cost. Moreover, the heat generated by the oxidation reaction causes powder to adhere to the mixing container, storage container, transfer container, hopper, etc., which may cause corrosion of these devices or damage the devices. However, there is a problem that a huge amount of labor is required for the work of removing the adhered powder and the work of cleaning in order to reduce such adverse effects. Further, there is a problem that continuous mixing cannot be performed.

[0006] Further, conventionally, since the powder is mixed and transferred in a state where it is exposed to the outside air by the above-mentioned mixing method and a belt conveyor, etc., dust is likely to be scattered at the work site, which makes the working environment poor, and There are also problems such as the need for air conditioning equipment and dust collectors for improvement.

The present invention has been made in order to solve the above problems, and by mixing two or more kinds of powders such as iron powder and a water retention agent, which are raw materials for disposable body warmers, while avoiding contact with air. A powder mixing device for a disposable body warmer that suppresses an oxidation reaction, can manufacture a body warmer having a desired heat generation performance, prevents powder from adhering to the inside of a hopper, and prevents dust from scattering at a work site. It is an object to provide a disposable body warmer manufacturing apparatus using the same.

[0008]

A powder mixing apparatus for a disposable body warmer according to the present invention comprises: (a) a plurality of raw material tanks for supplying raw materials for a disposable body warmer; and (b) a plurality of raw material tanks arranged below the raw material tanks. A metering / charging device for metering and charging the raw material, and (c) a cylindrical body extending in the vertical direction, and a plurality of supply ports for receiving the raw material from the metering / charging device at the upper part. A mixing cylinder having a discharge port formed in the lower portion, and (d) a mixing screw rotatably provided inside the mixing cylinder and having a maximum width smaller than the inner diameter of the mixing cylinder, (E) A driving means for rotating the mixing screw, and (f) a shutter provided at the discharge port of the mixing cylinder so as to be openable and closable.

A water inlet may be further formed in the mixing cylinder.

Preferably, the distance between the inner surface of the mixing cylinder and the outermost portion of the mixing screw becomes smaller as the mixing cylinder and the mixing screw move downward.

Further, in a disposable body warmer manufacturing apparatus using the disposable body warmer powder mixing apparatus, the mixed powder is packaged in a discharge port of the mixing cylinder with a breathable base material and the base material is used. It is characterized in that a main body of a packaging mechanism for processing into a closed bag is attached.

When performing the mixing operation using the powder mixing device for a disposable body warmer of the present invention, first, the metering / charging device is introduced into the mixing cylinder through the upper part, for example, the first supply port and the second supply port. Weigh iron powder and water retention agent using
throw into. Inside the mixing cylinder, the mixing screw is rotated by the driving means in the direction in which the mixture moves upward. Therefore, the powder introduced into the mixing cylinder has two movements, namely, a movement that falls between the mixing screw and the inner wall of the mixing cylinder, and a movement that is lifted from below by the screw threads of the mixing screw and rises. By repeating, it is mixed uniformly. At this time, since the powders are mixed inside the almost completely closed mixing cylinder, they hardly scatter out of the mixing cylinder. Moreover, since there is almost no time to contact with air (in particular, oxygen), heat generation of the powder is reduced in the downstream packaging mechanism after mixing. When the mixing of the powders is completed and the shutter is opened, the powders can be easily taken out by free fall through the discharge port.

Further, the shutter is opened in advance by a predetermined opening so that continuous mixing can be carried out while continuously charging, and the mixture and the discharge port can be continuously freely moved by the same volume as the powder charged from each supply port. You may drop it.

Further, in a disposable body warmer manufacturing apparatus using the powder blender for a disposable body warmer, after powders are mixed inside a sealed mixing cylinder, the powder is directly dropped into a hopper of a packaging mechanism through a discharge port, After that, it is supplied to the main body of the packaging mechanism. Therefore, it is not necessary to transfer the powder between the mixing device and the hopper by contacting the air with a belt conveyor or the like as in the conventional case, so that there is almost no time to contact the air (in particular, oxygen among them). Therefore, heat generation of the powder in the filling and packaging section after the mixing is reduced, and the powder is not clogged in the hopper, and the powder does not adhere to the hopper, the mixer, and the transport facility.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a powder mixing apparatus for a disposable warmer and a disposable warmer manufacturing apparatus using the same according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional explanatory view showing an embodiment of a disposable body warmer manufacturing apparatus using the disposable body warmer powder mixing apparatus of the present invention.

FIG. 1 shows a disposable body warmer according to an embodiment of the present invention, in which a powder blender for disposable body warmers 1 (hereinafter, simply referred to as a mixer), a hopper 2 and a packaging mechanism body 3 are sequentially arranged below. Manufacturing equipment is shown.

First, the mixing apparatus 1 will be described in detail.

The mixing device 1 is a device for mixing and stirring iron powder, which is a raw material of a disposable body warmer, and other additives (water retaining agent, water, etc.) in a state of being isolated from air inside the mixing cylinder 4. Above the mixing cylinder 4, a first tank 5 containing iron powder and a second tank 6 containing a water retention agent are provided.
Is provided. A mixing screw 7 is rotatably provided inside the mixing cylinder 4. A motor 8 for rotating the mixing screw 7 is provided at the upper end of the mixing cylinder 4, and a shutter 9 for opening and closing the discharge port 12 of the mixing cylinder 4 is provided at the lower end of the mixing cylinder 4. There is.
Although not shown in the drawings, near the outlets 5a, 6a opened at the bottoms of the first tank 5 and the second tank 6, the measuring / conveying materials conventionally used for measuring and charging the raw materials in the respective tanks are provided. A dosing device is provided.

The mixing cylinder 4 is made of a straight pipe such as an acrylic pipe, a stainless steel pipe, an iron pipe, and the openings at the upper and lower ends thereof are closed by an upper lid 13 and a lower lid 14, respectively. A first supply port 10 and a second supply port 11 are formed on the upper lid 13, and the first supply port 10 and the second supply port 10 are formed.
At the supply port 11, the first tank 5 and the second tank 6 are provided.
Outlets 5a and 6a are connected respectively. further,
A coupling 15 that rotatably supports the mixing screw 7 is fixed to a position between the first supply port 10 and the second supply port 11 of the upper lid 13. On the other hand, the lower lid 1
A discharge port 12 having a size substantially equal to the inner diameter of the mixing cylinder 4 is formed in the nozzle 4. Further, a pair of guide rails (not shown) are provided on the lower surface of the lower lid 14, and the flat shutter 9 is slidably supported by the guide rails.
A water inlet 16 is formed on the side wall of the mixing cylinder 4. Therefore, water can be directly injected into the powder being mixed in the mixing cylinder 4 through the water inlet 16 via the water supply pipe (not shown), and it is not necessary to consider the loss of water. , Can adjust the optimum water content.
The water to be injected may be simple water or saline.

In the present embodiment, an example of injecting water from the water inlet 16 has been described, but the present invention is not limited to this, and water is supplied to the second tank 6 on the water retention agent side. Water may be added to the water retention agent in advance by injecting it. In this case, it is necessary to consider the loss of water.

In the present embodiment, an example of a straight tube mixing cylinder has been described, but the present invention is not limited to this, and the shape may be changed appropriately. For example, if the mixing cylinder has a tapered shape, that is, if the inner diameter becomes smaller as it goes downward, the powder accumulated in the lower part of the mixing cylinder 4 can be guided to the root of the mixing screw 7. Alternatively, the mixture falling between the cylinder and the screw can be moved toward the screw center again and lifted to the upper part to improve the mixing state.

In the present embodiment, an example in which the inner diameter of the mixing cylinder 4 is reduced as it goes downward has been described, but the present invention is not limited to this, and the mixing cylinder 4 is not limited to this. If the distance between the inner surface of the mixing cylinder 4 and the outermost portion of the mixing screw 7 is reduced as the mixing screw 7 moves downward, the powder can be moved toward the screw side as described above. . Therefore, as another example, the above-described operation can be achieved by combining, for example, the straight pipe mixing cylinder 4 and the mixing screw 7 whose outer diameter increases as it goes downward.

Further, a straight tube is adopted as the mixing cylinder 4, and a cylindrical baffle plate whose wall thickness increases downwardly is fixed to the inner peripheral surface of the mixing tube 4 by adhesion or the like to improve the mixing state. You can In this case, the baffle plate may be provided only in the vicinity of the lower end of the mixing cylinder 4, or may be provided in a plurality of places including the vicinity of the central portion and the upper end.

For the first tank 5 and the second tank 6, a taper-shaped hopper which is conventionally used and which becomes thinner as it goes down is adopted. In addition, in the present embodiment, an example in which the number of tanks is two has been described, but the present invention is not limited to this, and may be appropriately performed when an additive other than iron powder and a water retention agent is added. You may add a tank.

In the mixing screw 7, a screw thread 7b is spirally extended around the shaft 7a so that the maximum width is smaller than the inner diameter of the mixing cylinder 4 in order to provide a clearance for allowing the powder to fall. The screw may be, for example, iron plated with chrome. Mixing screw 7
The pitch is appropriately selected according to the degree of mixing. Also,
You may make it change the pitch of an upper part and a lower part.

A commercially available motor is used as the motor 8 for rotating the mixing screw 7, and the motor 8 is
The rotation speed of the inverter (control panel) S (for example, FR
Z12-0.4KP; manufactured by Mitsubishi Electric Corporation.

As the shutter 9, a flat plate-like member is slidably supported as described above, and the handle 17 provided on the end edge of the shutter 9 is pulled or pushed to arbitrarily set the shutter 9. The outlet 12 can be opened and closed. The shutter 9 may be opened and closed manually, or automatically opened and closed, for example, by converting the driving force of a motor or the like into a linear driving force via a worm gear mechanism or the like, the shutter can be automatically opened and closed. Alternatively, it may be opened or closed by an air cylinder.

When performing the mixing operation using the mixing apparatus of FIG. 1, first, the first supply port 10 and the second supply port 10 in the upper part are introduced from the first tank 5 and the second tank 6 into the sealed mixing cylinder 4. Through the supply port 11, the iron powder and the water retention agent are metered and charged using the metering and charging device (not shown). Also, water or saline is injected through the water inlet 16.
Inside the mixing cylinder 4, the mixing screw 7 is rotated by the motor 8 in the direction in which the mixture moves upward. Therefore, the powder charged in the mixing cylinder 4 is
By repeating two movements, a movement that falls between the mixing screw and the inner wall of the mixing cylinder (arrow I), and a movement that is lifted from below by the threads 7b of the mixing screw 7 (arrow II). , Evenly mixed. At this time, since the powder is mixed inside the closed mixing cylinder 4, it hardly scatters to the outside of the mixing cylinder 4. Moreover, since there is almost no time to come into contact with air (in particular, oxygen thereof), heat generation of the powder is reduced in the downstream packaging mechanism (the hopper 2 and the packaging mechanism main body 3) after mixing. When the powder mixture is completed, the shutter 9
When opened, the powder can be easily transferred to the hopper 2 of the packaging mechanism by freely falling through the discharge port 12.

In addition, in the mixing apparatus of the present invention, the powder is dropped from the gap between the mixing screw 7 and the inner wall of the mixing cylinder 4, and the powder is forcibly lifted by the mixing screw 7 to mix the powder. I am doing it. for that reason,
By appropriately changing the specifications of the mixing cylinder 4 and the mixing screw 7, for example, by changing the rotation speed of the mixing screw 7, the pitch of the mixing screw 7 or the inner diameter of the mixing cylinder 4, the required amount of powder can be obtained at the required speed. It can be mixed continuously.

Further, the shutter 9 is opened in advance by a predetermined opening so that continuous mixing can be performed while continuously feeding the mixture, and the same amount of the mixture as that of the powder fed from the respective supply ports 10 and 11 and the discharge port. You may make it fall continuously continuously. By such continuous mixing, a large amount of powder can be quickly mixed. When performing continuous mixing,
It suffices to close the shutter 9 only at the beginning of mixing to mix the powders inside the mixing cylinder 4, and after the desired mixing state is reached, open the shutter 9 to perform continuous mixing.

Further, a cylinder (not shown) for temporary storage may be provided between the shutter 9 and the hopper 2 of the downstream packaging mechanism so that batch mixing can be performed. In this case,
First, the powders are mixed with the shutter 9 closed, and after the mixing is completed, the shutter 9 is opened and the whole mixture is allowed to fall freely into the tube for temporary storage. After that, the shutter 9 is closed and all the mixture in the cylinder for temporary storage is supplied to the downstream packaging mechanism at a predetermined supply rate through, for example, a chute (not shown), and in parallel with that, Powder mixing is performed in the mixing cylinder. By such batch mixing, a large amount of powder can be rapidly mixed, and the mixed state of the obtained mixture can be kept uniform.

If a vacuum device or a gas replacement device for evacuating the inside of the mixing cylinder 4 according to the contents or enclosing nitrogen gas or an inert gas is also provided, the mixing cylinder 4 can be provided. It is possible to more effectively prevent the powder from coming into contact with oxygen inside.

As a packaging mechanism, a hopper 2 for storing the mixed powder discharged from the discharge port 12 of the mixing cylinder 4 is connected to the downstream side of the mixing device 1 configured as described above, and the hopper 2 is connected to the hopper 2. A packaging mechanism body 3 for packaging the mixed powder in a breathable base material and processing the base material into a sealed bag at the lower end outlet 2a of
Is attached to form a disposable body warmer manufacturing apparatus.

The packaging mechanism body 3 is composed of a fixed amount supply unit 18 and a packaging unit 19.

The fixed quantity supply part 18 is a part for supplying the powder inside the hopper 2 to the packaging part 19 by the volume filled in one bag of the disposable body warmer, and is provided at the outlet 2a of the hopper 2. The supply drum 20 and the chute 21
A swing plate 22 that is swingably provided inside the chute 21.
From the distribution member 23 that is horizontally movable below the chute 21, the drive roller 24 for horizontally driving the distribution member 23, the bottom plate 26, the first individual chute 27, and the second individual chute 29. It is configured.

The supply drum 20 is a member having a cylindrical shape in which grooves are formed on the outer peripheral surface along the direction perpendicular to the paper surface. The powder dropped from the hopper 2 is first stored in the groove of the outer peripheral surface of the supply drum 20, and then the supply drum 20.
The powders stored in the respective grooves are quantitatively dropped onto the chute 21 with the rotation of the.

The swing plate 22 is swingably provided around the rotary shaft 22a, and moves to the left side in the figure when the amount of the mixed powder supplied into the chute 21 becomes too large.
It acts on a separately provided limit switch (not shown) or the like to stop the rotation of the supply drum 20, that is, the supply of the mixed powder.

The distribution member 23 is a plate-like member in which a plurality of fixed-quantity pockets 25 having a volume equivalent to one bag are arranged along the direction perpendicular to the plane of the drawing, and are horizontally arranged by rails (not shown) or the like. It is movably supported by. The fixed quantity pocket 25 is a space portion whose upper and lower sides are open, and the lower end thereof is closed by a bottom plate 26 so that powder does not leak. The distribution member 23 can be moved from the position immediately below the supply drum 20 to the position immediately above the first individual chute 27.

Similar to the distribution member 23, the bottom plate 26 is supported by rails (not shown) and the like so as to be movable in the horizontal direction, and the engagement member (not shown) capable of engaging with and disengaging from the distribution member 23. Are linked by. Bottom plate 26
Moves while being connected to the distribution member 23. Moreover,
Since the connection by the locking member is released almost immediately before the first individual chute 27, the bottom plate 26 cannot move upward of the first individual hopper 27.

The first individual chute 27 is a fixed chute arranged corresponding to each of the plurality of fixed quantity pockets 25, and a shutter 28 is swingably provided at the outlet thereof.

The second individual chutes 29 are vertically movable chutes arranged corresponding to the plurality of quantitative pockets 25. Second individual shoot 29
Is moved vertically in a predetermined cycle by a drive cam mechanism (not shown) or the like.

With this structure, when the powder is quantitatively supplied by the quantitative supply unit 18, first, the quantitative pocket 25 is used.
Is moved to a position just below the supply drum 20, and the mixed powder in the chute 21 is filled in the fixed amount pocket 25.

After that, the drive roller 24 is rotated counterclockwise by a motor (not shown), and the distribution member 23,
And the bottom plate 26 connected to the distribution member 23 by the locking member is moved to the left. At this time, the bottom plate 26 is released from the connection by the locking member almost immediately before the first individual chute 27 and stops moving at such a position, but the distribution member 23 is
Move further to the left. Therefore, the quantitative pocket 25
Since the lower end opening is opened just above the first individual chute 27, the powder in the fixed amount pocket 25 is dropped to the first individual chute 27. After the supply of the powder to the first individual chute 27 is completed, the distribution member 23 returns to the initial position by rotating the drive roller 24 in the reverse direction. At that time, the bottom plate 26 is again connected to the distribution member 23 by the locking member.

In the first individual chute 27, the shutter 28 is opened in advance, and the powder is allowed to fall freely on the second individual chute 29. After the supply of the powder to the second individual chute 29 is completed, the shutter 28 is closed in conjunction with the movement of the distribution member 23 to the right, thereby preventing the remaining powder from falling.

Finally, while the second individual chute 29 is moved in the vertical direction at a predetermined cycle by the drive cam mechanism (not shown) or the like, the powder is packed in the packaging section 19 (specifically,
By freely dropping it between the pair of die rolls 30, the powder can be smoothly packed in order from the back of the bag manufactured by the packaging unit 19. That is, the second individual hopper 29 is at the lower end position at the beginning of filling one bag, and is raised in synchronization with the rotation of the die roll 30. The above-described series of quantitative supply of powder is repeatedly performed.

In the present embodiment, an example in which a plurality of fixed quantity pockets 25 and a plurality of first and second individual chutes 27, 29 are arranged for mass production has been described, but the present invention is not limited to this. It is needless to say that the present invention is not limited to the above and may be provided one by one.

The packaging unit 19 includes a pair of die rolls 30 for heat sealing, and a heater H for heating is built in the die rolls 30. Moreover, on the outer peripheral surface of the die roll 30, a rectangular concave portion 32 corresponding to the shape of the front surface or the back surface of the bag to be manufactured is formed.
Are formed at equal intervals along the axial direction and the circumferential direction. Further, the ridges 31 are provided so as to project in the axial direction and the circumferential direction of the die roll 30 along the outer peripheral edge of the recess 32.

When the pair of die rolls 30 rotates in the direction in which the pair of air-permeable base materials B are wound, the ridges 31 extending in the axial direction of the die rolls 31 face each other every 120 degrees, so that the base materials B are joined to each other. Can be heat-sealed, and the side edges of the base material B can be heat-sealed by the protrusions 31 (not shown) extending in the circumferential direction of the die roll 30. Therefore, the pair of die rolls 30 can wind up the pair of base materials B to continuously form a bag. Since the second individual hopper 29 of the fixed quantity supply unit 18 is disposed above the intermediate position of the pair of die rolls 30, powder is formed between the pair of die rolls 30 from the hopper 29 while forming a bag. It can be dropped and the powder can be packed continuously.

In the disposable body warmer manufacturing apparatus using the above-mentioned mixing device, the powder is mixed in the sealed mixing cylinder 4 and then directly dropped into the hopper 2 through the discharge port 12 and then to the packaging mechanism main body 3. Supplied. Therefore, it is not necessary to transfer the powder between the mixing device 1 and the hopper 2 by contacting the air with a belt conveyor or the like as in the conventional case, so that there is almost no time to contact the air (in particular, oxygen among them). . Therefore, after the mixing, heat generation of the powder in the downstream packaging mechanism (the hopper 2 and the packaging mechanism main body 3) is reduced, the powder is agglomerated inside the hopper 2, and the powder is not collected in the hopper 2 and the packaging mechanism main body 3. There is no problem such as adhesion.

The bags made continuously are individually cut and separated by a conventionally known method, and then inspected as to whether or not they are empty bags.

[0051]

According to the mixing apparatus of the present invention, the oxidation reaction is suppressed by mixing two or more kinds of powder such as iron powder, which is a raw material for disposable body warmers, and a water retention agent while avoiding contact with air, It is possible to manufacture a body warmer having a desired heat generation performance. Moreover, since the powders are mixed inside the almost closed mixing cylinder, the dust is less scattered and the powders do not clump.

Further, in the disposable body warmer manufacturing apparatus using the above-mentioned mixing device, after the powder is mixed inside the sealed mixing cylinder, it is directly dropped into the hopper of the packaging mechanism through the discharge port, and then the packaging mechanism main body. Is supplied to. Therefore,
Since it is not necessary to transfer the powder between the mixing device and the hopper by contacting the air with a belt conveyor or the like as in the conventional case, there is almost no time to contact the air (in particular, oxygen among them). Therefore, after the mixing, heat generation of the powder in the downstream packaging mechanism is reduced, and the powder is not clogged inside the hopper, and the powder does not adhere to the hopper and the packaging mechanism main body.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing an embodiment of a disposable body warmer manufacturing apparatus using a powder blender for a disposable body warmer of the present invention.

[Explanation of symbols]

 1 Mixing device 2 Hopper 3 Packaging mechanism main body 4 Mixing cylinder 5 First tank 6 Second tank 7 Mixing screw 8 Motor 9 Shutter 10 First supply port 11 Second supply port 12 Discharge port

Claims (4)

[Claims] 1. A plurality of raw material tanks for supplying raw materials for a disposable body warmer, and (b) a weighing / charging device which is disposed below each of the raw material tanks and which measures and doses the raw materials. And (c) a mixing cylinder which is composed of a vertically extending cylindrical body and has a plurality of supply ports for receiving the raw materials from the weighing / charging device at the upper part and a discharge port at the lower part, (D) a mixing screw that is rotatably provided inside the mixing cylinder and has a maximum width smaller than the inner diameter of the mixing cylinder; and (e) drive means for rotating the mixing screw. (F) A powder mixing apparatus for a disposable body warmer, which comprises a shutter that is openably and closably provided at an outlet of the mixing tube. 2. The powder mixing device for a disposable body warmer according to claim 1, wherein a water inlet is further formed in the mixing cylinder. 3. The disposable body warmer according to claim 1, wherein the distance between the inner surface of the mixing cylinder and the outermost portion of the mixing screw becomes smaller as the mixing cylinder and the mixing screw move downward. Powder mixing device. 4. A disposable body warmer manufacturing apparatus using the powder blender for disposable body warmers according to claim 1, wherein the mixed powder is packed in a discharge port of the mixing cylinder with a breathable base material. In addition, the main body of a packaging mechanism for processing the base material into a closed bag is attached to the disposable body warmer manufacturing apparatus.