SPRAY DEVICE AND COMPRESSION MOLDING MACHINE INCLUDING THE SAME

A spray device includes an upper punch spray nozzle configured to spray a spray agent to a lower end surface of an upper punch, a lower punch spray nozzle configured to spray a spray agent to an upper end surface of a lower punch and an inner peripheral surface of a die bore, a first suction port configured to suck the sprayed spray agent, and a guide member configured to guide the spray agent sprayed from the upper punch spray nozzle to the first suction port. The guide member is configured to be located above the upper punch spray nozzle.

BACKGROUND

When compression molding a powdery material to produce a molded product, the powdery material is typically mixed with a lubricant (i.e., internal lubricant) in order to improve mold releasability of the molded product from a mold tool (i.e., a punch and a die).

According to an alternative method, a lubricant (external lubricant) is sprayed to a mold tool before a die bore is filled with a powdery material, and the powdery material is compression-molded to produce a molded product. This method is effective also in the production of an orally disintegrating tablet.

An invention disclosed in JP 2006-334515 A relates to a powder lubricant spray device configured to spray a powder lubricant (i.e., an external lubricant) to a mold tool. According to this invention, a spray member25is rotated to spray the powder lubricant to the mold tool.

However, the invention disclosed in JP 2006-334515 A is applicable only to a rotary compression molding machine and is not applicable to a single stroke compression molding machine because a spray device2is fixed by an attachment member14so as to be immovable, as shown in FIGS. 4 and 5 of JP 2006-334515 A.

SUMMARY OF THE INVENTION

It is an exemplary feature of the present invention to provide a spray device applicable to a single-stroke compression molding machine.

The invention provides a spray device applicable to a compression molding machine including a die table having a vertically penetrating die bore, a lower punch having an upper end that is inserted to the die bore and is slidable therein, and an upper punch having a lower end that is inserted to the die bore and is slidable therein. The spray device is configured to reciprocate on the die table and includes an upper punch spray nozzle configured to spray a spray agent to a lower end surface of the upper punch, a lower punch spray nozzle configured to spray a spray agent to an upper end surface of the lower punch and an inner peripheral surface of the die bore, a first suction port configured to suck the sprayed spray agent, and a guide member configured to guide the spray agent sprayed from the upper punch spray nozzle to the first suction port, wherein the guide member is configured to be located above the upper punch spray nozzle.

The exemplary spray device as configured above is applicable to a single-stroke compression molding machine. Provision of the guide member prevents the spray agent from being excessively sprayed to the lower end surface of the upper punch. Examples of the spray agent sprayed by the spray device include a lubricant (e.g., external lubricant), as well as various agents such as a partitioning agent, a binding agent, and a dividing agent.

A powdery material refers to an aggregate of minute solids and conceptually includes what are called “granules” and powder smaller than particles. The powdery material can also include a lubricant (e.g., internal lubricant).

The lower and upper punches are preferred to be mold tools applicable to a rotary compression molding machine (e.g., particularly conforming to the TSM Standards or the EU Standards). Such lower and upper punches almost achieve the state of use in a rotary compression molding machine.

The upper punch spray nozzle preferably reciprocates relatively to the guide member. Specifically, the upper punch spray nozzle preferably reciprocates between a predetermined position below the upper punch and a retreating position below the guide member.

When the upper punch spray nozzle as configured above is located at the retreating position, the spray agent sprayed from the upper punch spray nozzle is guided by the guide member and sucked through the first suction port. Accordingly, the spray agent is not sprayed toward a point other than a required point.

The invention also exemplary provides a spray device applicable to a compression molding machine including a die table having a vertically penetrating die bore, a lower punch having an upper end that is inserted to the die bore and is slidable therein, and an upper punch having a lower end that is inserted to the die bore and is slidable therein. The spray device is configured to reciprocate on the die table and includes an upper punch spray nozzle configured to spray a spray agent to a lower end surface of the upper punch, a lower punch spray nozzle configured to spray a spray agent to an upper end surface of the lower punch and an inner peripheral surface of the die bore, a first suction port configured to suck the sprayed spray agent; and a guide member configured to guide the spray agent sprayed from the upper punch spray nozzle to the suction port, wherein the upper punch spray nozzle reciprocates between a predetermined position below the upper punch and a retreating position below the guide member.

The spray device as configured above is applicable to a rotary compression molding machine as well as to a single-stroke compression molding machine. When the upper punch spray nozzle is located at the retreating position, the spray agent sprayed from the upper punch spray nozzle is guided by the guide member and sucked through the first suction port. Therefore, the spray agent sprayed toward a point other than a required point can be sucked.

The invention further exemplary provides a spray device applicable to a compression molding machine including a die table having a vertically penetrating die bore, a lower punch having an upper end that is inserted to the die bore and is slidable therein, and an upper punch having a lower end that is inserted to the die bore and is slidable therein, the spray device including a spray nozzle configured to spray a spray agent and configured to reciprocate on the die table, the spray device further including a first suction port configured to suck the sprayed spray agent, a guide member configured to guide the spray agent sprayed to a lower end surface of the upper punch to the first suction port, a lower punch spray nozzle configured to spray a spray agent to an upper end surface of the lower punch and an inner peripheral surface of the die bore, and an upper punch spray nozzle configured to spray an external lubricant to the lower end surface of the upper punch and reciprocate between a predetermined position below the upper punch and a retreating position below the guide member.

The spray device as configured above is applicable to a rotary compression molding machine as well as to a single stroke compression molding machine. When the upper punch spray nozzle is located at the retreating position, the spray agent sprayed from the upper punch spray nozzle is guided by the guide member and sucked through the first suction port. Therefore, the spray agent sprayed toward a point other than a required point can be sucked.

The spray device preferably has, at a bottom surface, a suction space used for suction of a spray agent sprayed from the lower punch spray nozzle onto the die table. The spray device as configured above can suck the spray agent sprayed onto the die table.

The spray device preferably includes a second suction port configured to suck the spray agent sprayed from the upper punch spray nozzle when the spray device is located at the retreating position and the upper punch spray nozzle is located at the predetermined position. The spray device as configured above can suck the spray agent sprayed toward a point other than a required point even when the upper punch spray portion (e.g., upper punch spray nozzle) moves to the predetermined position before the spray device moves to an upper punch spray position.

In an exemplary aspect of the present invention, a compression molding machine includes a die table having a vertically penetrating die bore, a lower punch having an upper end that is inserted to the die bore and is slidable therein, and an upper punch having a lower end that is inserted to the die bore and is slidable therein. Preferably, the compression molding machine further includes the spray device described above. The compression molding machine as configured above can produce, using the spray device, a molded product that is compression-molded by the upper punch and the lower punch.

The spray device according to the invention is applicable to a single-stroke compression molding machine and a rotary compression molding machine.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention will now be described with reference to the drawings. A compression molding machine according to an exemplary embodiment relates to a single stroke compression molding machine configured to produce a compression molded product such as an orally disintegrating tablet or a double layer tablet. When the compression molded product is a pharmaceutical tablet, the tablet is made of a powdery material containing an active ingredient or a powdery material containing an active ingredient and an excipient. According to the exemplary embodiment of the invention, an external lubricant spray device is adopted as a spray device and an external lubricant is adopted as a lubricant.

As shown inFIGS. 1 to 5, the compression molding machine according to the exemplary embodiment (hereinafter, referred to as “a molding machine”) principally includes a die table1having a die bore12to be filled with a powdery material, a lower punch6located below the die bore12and configured to compress the powdery material filled in the die bore12, an upper punch7located above the die bore12so as to face the lower punch6and configured to compress the powdery material filled in the die bore12along with the lower punch6, feeders2A and2B each configured to fill the die bore12with a powdery material, a dust collector3configured to collect dust on the upper surface of the die table1, and an external lubricant spray device configured to spray an external lubricant to the upper punch7, the lower punch6, and the interior of the die bore12.

Examples of the feeders2A and2B include a feed shoe. Two feeders (2A and2B) are provided in the exemplary embodiment, but only one feeder can be provided.

The die table1is provided with a die installation portion13into which a die11is mounted. The die11has the die bore12penetrating vertically, and conforms to the TSM Standards or the EU Standards. This die11is applicable to an ordinary rotary compression molding machine. The die table1can be directly provided with the die bore12penetrating vertically, instead of having the die11.

The lower punch6is retained at a lower punch retaining portion4such that the upper end (e.g., a punch tip) thereof is inserted to the die bore12and is slidable relatively to the die bore12. The upper end of the lower punch6is constantly inserted to the die bore12. The lower punch6is moved upward and downward by a drive source such as a servo motor (not shown).

The upper punch7is retained at an upper punch retaining portion5such that the lower end (e.g., a punch tip) thereof is inserted to the die bore12and is slidable relatively to the die bore12. The lower end of the upper punch7enters and exits the die bore12. Similarly to the lower punch6, the upper punch7is moved upward and downward by a drive source such as a servo motor (not shown).

Like the die11, the lower punch6and the upper punch7each conform to the TSM Standards or the EU Standards. The lower punch6and the upper punch7are applicable to a rotary compression molding machine.

The feeders2A and2B each may include a conveyance member21configured to slide relatively to the upper surface of the die table1and convey a powdery material to the die bore12, and a hopper22configured to supply the conveyance member21with a powdery material. The conveyance member21may be a plate having a space211that has an internal diameter larger than that of the die bore12and penetrates vertically.

The conveyance member21is reciprocated between a filling position indicated inFIG. 4and a retreating position indicated inFIGS. 2, 3, and 5by a drive source such as a servo motor (not shown) while storing a powdery material in the space211. The conveyance member21located at the filling position covers a region around the die bore12on the upper surface of the die table1. The space211is located vertically above the die bore12and the die bore12is filled with the powdery material in the space211.

The conveyance member21located at the retreating position retreats from the region around the die bore12on the upper surface of the die table1and releases the region. The space211is located vertically below a supply port of the hopper22, and is supplied with the powdery material in the hopper22.

The distal end (e.g., closer to the die bore12) of the conveyance member21has a lower surface serving as a leveling plate212. After a powdery material is transferred from the space211to the die bore12, the leveling plate212levels a powdery material overflown from the die bore12due to upward movement of the lower punch6and removes the excessive powdery material on the die bore12.

The hopper22has the upper portion expanding upward like a funnel. An operator of the molding machine supplies a powdery material to the hopper22so as to be filled in the die bore12.

As shown inFIG. 1, the exemplary embodiment provides two feeders2A and2B that move toward and away from the die bore12in two different directions when viewed from the die bore12and fill the die bore12with a powdery material. The feeders2A and2B are in common in terms of the structure and the mechanism as described above. The hoppers22in the feeders2A and2B can be fed with different types of powdery materials or a same powdery material.

As shown inFIGS. 2 to 5, the dust collector3includes a driver31configured to move upward and downward along with the upper punch7, a dust collecting case32configured to move upward and downward along with the upper punch7by the driver31to cover the region around the die bore12on the upper surface of the die table1, and a suction duct33connected to the dust collecting case32and configured to decompress the dust collecting case32.

The driver31according to the exemplary embodiment has a vertically extending shaft shape in parallel with the upper punch7, and is retained at the retaining portion5that also retains the upper punch7. The upper end of the driver31is coupled to the drive source such as a servo motor as the upper end of the upper punch7is, and moves upward and downward along with the upper punch7. Unlike the upper punch7, the driver31can be displaced within a certain range in the vertical direction relatively to the drive source.

The dust collecting case32has an upper wall321and side walls322extending vertically downward from the peripheral edges of the upper wall321so as to surround an internal space323. The dust collecting case32has a box shape with an open bottom face. The upper wall321has a portion located vertically above the die bore12and is provided with a punch insertion bore324that penetrates vertically and allows the upper punch7to be inserted therethrough. The upper wall321also has a portion located vertically below the driver31and is provided with an engagement bore325that is engaged with the lower end of the driver31.

The upper surface of the upper wall321of the dust collecting case32vertically faces the lower surface of the upper punch retaining portion5. A biasing member34exerting elastic bias force is provided between the dust collecting case32and the upper punch retaining portion5. The biasing member34presses the dust collecting case32so as to come into close contact with the upper surface of the die table1during dust collection. Examples of the biasing member34may include a compression coil spring34that is elastically deformable.

The dust collecting case32reciprocates between a dust collecting position indicated inFIG. 5and a releasing position indicated inFIGS. 2 to 4. When the dust collecting case32is located at the dust collecting position, the upper wall321and the side walls322of the dust collecting case32surround the region around the die bore12on the upper surface of the die table1to isolate this region from the remaining region. When the lower end of the upper punch7is inserted to the die bore12to compress the powdery material in the die bore12, the driver31is displaced upward relatively to the drive source and the upper punch7in accordance with the amount of vertical displacement of the upper punch7relative to the die table1and the die bore12. In this state, the compression coil spring34located between the lower surface of the upper punch retaining portion5and the upper surface of the dust collecting case32expands appropriately to press the dust collecting case32against the upper surface of the die table1without applying unreasonable force to the dust collecting case32.

The dust collecting case32located at the releasing position releases the region around the die bore12on the upper surface of the die table1. The compression coil spring34is compressed because of a reduced distance between the lower surface of the upper punch retaining portion5and the upper surface of the dust collecting case32.

The suction duct33is provided continuously from the proximal end of the dust collecting case32. The interior of the suction duct33communicates with the internal space323of the dust collecting case32. The suction duct33is connected to an ejector (e.g., a fluid pump; not shown) configured to generate suction force. The ejector decompresses the suction duct33and the internal space323of the dust collecting case32with its suction force, so as to suck and remove dust and dirt such as a powdery material on the die table1facing the internal space323of the dust collecting case32. Generation timing and degree of the suction force of the ejector can be controlled by operating a solenoid valve (not shown) that is located on a flow path between the dust collecting case32and the ejector.

As shown inFIGS. 1 and 6, an external lubricant spray device8serving as an exemplary spray device includes an upper punch spray portion81configured to spray an external lubricant to the lower end surface of the upper punch7, a cylinder812serving as an exemplary upper punch spray portion drive unit configured to drive the upper punch spray portion81, a lower punch spray portion82configured to spray an external lubricant to the upper end surface of the lower punch6and the interior of the die bore12, a first suction duct83configured to suck an excessive external lubricant, a guide member84configured to guide an external lubricant to a first suction port831, and a second suction duct86configured to suck an excessive external lubricant.

The external lubricant spray device8reciprocates among a retreating position, an upper punch spray position, and a lower punch spray position on the die table1in an X axis direction indicated inFIGS. 6 and 7. An external lubricant is sprayed to the lower end surface of the upper punch7when the external lubricant spray device8is located at the upper punch spray position, whereas an external lubricant is sprayed to the upper end surface of the lower punch6and the interior of the die bore12when the external lubricant spray device8is located at the lower punch spray position. An external lubricant is constantly sprayed in the exemplary embodiment. The external lubricant is electrically charged when the external lubricant spray device8is located at the upper punch spray position or the lower punch spray position. The external lubricant is not electrically charged otherwise and is sucked to the first or second suction duct83or86. This configuration is applicable to a spray agent other than an external lubricant.

As shown inFIG. 9, the upper punch spray portion81includes an upper punch spray portion main body816, an upper punch spray nozzle814opened to the upper surface of the upper punch spray portion main body816, and a charging member819having a distal end projecting to a path for an external lubricant.

The upper punch spray portion81has a bottom surface coupled to a first end of a coupling member813. The coupling member813has a second end coupled to the lower surface of the cylinder812. When the cylinder812reciprocates on the die table1in a Y axis direction, the upper punch spray portion81also reciprocates in the Y axis direction (e.g., the X axis direction, the Y axis direction, and a Z axis direction are indicated inFIGS. 1, 6, 7, and 8). When the upper punch spray portion81reciprocates in the Y axis direction, the upper punch spray nozzle814reciprocates between a predetermined position (FIG. 9) where an external lubricant can be sprayed to the lower end surface of the upper punch7and a retreating position (FIG. 10) below the guide member84.FIGS. 9 and 10show the state where the external lubricant spray device8is located at the upper punch spray position.

An external lubricant is injected to the upper punch spray portion81through a tube (not shown) connected to a supply port815, and is sprayed from the upper punch spray nozzle814. An external lubricant is constantly sprayed in the exemplary embodiment and is electrically charged when sprayed to the lower end surface of the upper punch7.

When the upper punch spray portion81is located at the predetermined position where an external lubricant can be sprayed to the lower end surface of the upper punch7and the external lubricant spray device8is located at the upper punch spray position, an external lubricant is sprayed to the lower end surface of the upper punch7. When the upper punch spray portion81is located at the retreating position, an external lubricant is sprayed to the lower surface of the guide member84and is sucked to the first suction duct83.

As shown inFIG. 11, the lower punch spray portion82includes a lower punch spray portion main body826, a lower punch spray nozzle824opened to the bottom surface of the lower punch spray portion main body826, and a charging member829having a distal end projecting to a path for an external lubricant.

The lower punch spray portion82is covered, around the lower punch spray nozzle824located at the bottom surface, with a projecting portion821in contact with the die table1, and has a space827(e.g., suction space) used for suction of an external lubricant sprayed onto the die table1. The space827is connected to a suction bore826that vertically penetrates the lower punch spray portion82, and the suction bore826is connected, adjacent to the upper surface of the lower punch spray portion82, to a suction path828. The guide member84to be described later is located above the suction path828.

An external lubricant is injected to the lower punch spray portion82through a tube (not shown) connected to a supply port825, and is sprayed from the lower punch spray nozzle824. An external lubricant is constantly sprayed in the exemplary embodiment and is electrically charged when sprayed to the upper end surface of the lower punch6and the interior of the die bore12. An external lubricant is sprayed from the lower punch spray nozzle824to the upper end surface of the lower punch6and the interior of the die bore12when the external lubricant spray device8is located at the lower punch spray position. In contrast, an external lubricant is sprayed onto the die table1when the external lubricant spray device8is located at a position other than the lower punch spray position. The external lubricant sprayed onto the die table1is sucked in the space827, moves upward through the suction bore826, and moves by way of the suction path828so as to be sucked to the first suction duct83.

The guide member84is located adjacent to the first suction duct83and partially configures the upper surface of the external lubricant spray device8. The guide member84has a box shape with an open lower surface, covers from above part of the upper punch spray portion81, the suction bore826, and the suction path828, and is partially connected to the first suction port831at the distal end of the first suction duct83.

The charging member819is configured to charge an external lubricant sprayed to the lower end surface of the upper punch7. The distal end of the charging member819is located adjacent to the upper punch spray nozzle814and charges an external lubricant sprayed from the upper punch spray nozzle814. The charging member829is configured to charge an external lubricant sprayed to the upper end surface of the lower punch6and the interior of the die bore12. The distal end of the charging member829is located adjacent to the lower punch spray nozzle824and charges an external lubricant sprayed from the lower punch spray nozzle824.

An external lubricant can be charged constantly or only in a case where the external lubricant is sprayed to the lower end surface of the upper punch7, the upper end surface of the lower punch6, and the interior of the die bore12. In order to charge an external lubricant only in a case where the external lubricant is sprayed to the lower end surface of the upper punch7, the upper end surface of the lower punch6, and the interior of the die bore12, the external lubricant can be charged only at a predetermined timing by a pulse or the like. The exemplary embodiment adopts this method to charge an external lubricant only in a case where the external lubricant is sprayed to the upper end surface of the lower punch6and the interior of the die bore12.

The first suction duct83is provided at the distal end with the first suction port831and is connected to the guide member84. The first suction duct83sucks an external lubricant excessively sprayed from the lower punch spray nozzle824onto the die table1and an external lubricant sprayed from the upper punch spray nozzle814to the lower surface of the guide member84.

The second suction duct86is provided at the distal end with a second suction port (not shown). When the upper punch spray portion81is located at the predetermined position where an external lubricant can be sprayed to the lower end surface of the upper punch7and the external lubricant spray device8is located at the retreating position, the second suction duct86sucks an external lubricant sprayed from the upper punch spray nozzle814.

The external lubricant spray device8will now be described in terms of a series of its operations. Initially, as shown inFIG. 1, the external lubricant spray device8is located at the retreating position and the upper punch spray portion81is also located at the retreating position. In this state, an external lubricant is sprayed from the upper punch spray nozzle814to the lower surface of the guide member84and is sucked through the first suction duct83. Meanwhile, an external lubricant is sprayed from the lower punch spray nozzle824onto the die table1and is sucked through the first suction duct83by way of the suction bore826.

Subsequently, in a state where the external lubricant spray device8is located at the retreating position, the upper punch spray portion81moves from the retreating position to the predetermined position where an external lubricant can be sprayed to the lower end surface of the upper punch7. In this state, an external lubricant sprayed from the upper punch spray nozzle814is sucked through the second suction duct86opened above the upper punch spray nozzle814. Meanwhile, an external lubricant is sprayed from the lower punch spray nozzle824onto the die table1and is sucked through the first suction duct83by way of the suction bore826.

The external lubricant spray device8subsequently moves from the retreating position to the upper punch spray position. The upper punch spray portion81stays at the predetermined position where an external lubricant can be sprayed to the lower end surface of the upper punch7. An external lubricant is sprayed from the upper punch spray nozzle814to the lower end surface of the upper punch. Meanwhile, an external lubricant is sprayed from the lower punch spray nozzle824onto the die table1and is sucked through the first suction duct83by way of the suction bore826.

The external lubricant spray device8subsequently moves from the upper punch spray position to the lower punch spray position and an external lubricant is sprayed from the lower punch spray nozzle824to the upper end surface of the lower punch6and the interior of the die bore12. Meanwhile, the upper punch spray portion81moves from the predetermined position to the retreating position. An external lubricant is sprayed from the upper punch spray nozzle814to the lower surface of the guide member84and is sucked through the first suction duct83.

The external lubricant spray device8subsequently moves from the lower punch spray position to the retreating position. The upper punch spray portion81stays at the retreating position. In this state, an external lubricant is sprayed from the upper punch spray nozzle814to the lower surface of the guide member84and is sucked through the first suction duct83. Meanwhile, an external lubricant is sprayed from the lower punch spray nozzle824onto the die table1and is sucked through the first suction duct83by way of the suction bore826. The upper punch spray portion81is located at the retreating position when the external lubricant spray device8moves to the retreating position. Accordingly, the upper punch spray nozzle814does not spray any excessive external lubricant to the lower end surface of the upper punch7.

Such a series of operations is performed repeatedly. The external lubricant spray device8in the exemplary embodiment moves from the retreating position to the upper punch spray position and then moves to the lower punch spray position. The external lubricant spray device8can alternatively move to the lower punch spray position before moving to the upper punch spray position. The order is not particularly limited.

An exemplary method of producing an orally disintegrating tablet using a molding machine according to the exemplary embodiment will now be described in terms of its specific procedure. At an initial stage of production of a molded product, the external lubricant spray device8and the conveyance member21of the feeder2A (or2B) are located at the retreating positions, respectively. This exemplary method requires only one of the feeders (2A and2B), and will be described below in the case where the feeder2A is provided. Neither the upper punch7nor the driver31descends, and the lower end of the upper punch7is not inserted to the die bore12. The dust collecting case32is located at the releasing position.

Initially, the external lubricant spray device8moves from the retreating position to the upper punch spray position and an external lubricant is sprayed from the upper punch spray nozzle814to the lower end surface of the upper punch. The upper punch spray portion81is subsequently moved to the retreating position. The external lubricant spray device8then moves from the upper punch spray position to the lower punch spray position and an external lubricant is sprayed from the lower punch spray nozzle824to the upper end surface of the lower punch and the interior of the die bore12. The external lubricant spray device8then moves from the lower punch spray position to the retreating position.

The feeder2A subsequently moves from the retreating position to the filling position and fills the die bore12with a powdery material. The lower punch6ascends to achieve a required amount of the powdery material, the leveling plate212at the lower surface of the conveyance member21levels and removes a powdery material overflown from the upper edge of the die bore12. The feeder2A then moves to the retreating position.

The upper punch7subsequently descends and the lower end thereof is inserted to the die bore12. The lower end of the upper punch7and the upper end of the lower punch6preliminarily compress the powdery material in the die bore12, and then mainly compress the same. The procedure may not optionally include the preliminarily compressing step.

The driver31, the dust collecting case32engaged with the driver31, and the suction duct33connected to the dust collecting case32descend along with the descending upper punch7, and the dust collecting case32moves to the dust collecting position. The lower end surfaces of the side walls322of the dust collecting case32located at the dust collecting position are in close contact with the upper surface of the die table1. In this state, the ejector generates suction force to decompress the internal space323of the dust collecting case32, so as to suck dust and dirt including a powdery material remaining in the region around the die bore12on the upper surface of the die table1. The lower end of the upper punch is inserted to the die bore12during this dust collecting step.

The upper punch7, the driver31, the dust collecting case32, and the suction duct33subsequently ascend, and the suction duct33moves to the releasing position.

The lower punch6is then ascended and the upper end thereof pushes a compression molded product out of the die bore12onto the die table1. The feeder2A discharges the compression molded product.

An exemplary method of producing a double layer tablet using the molding machine according to the embodiment as well as the external lubricant spray device8will now be described in terms of its specific procedure. The processes similar to those in the above method of producing an orally disintegrating tablet will not be described repeatedly. Similarly to the above method, at an initial stage of production of a molded product, the conveyance members21of the feeders2A and2B are at the retreating positions, respectively. Neither the upper punch7nor the driver31descends, and the lower end of the upper punch7is not inserted to the die bore12. The dust collecting case32is located at the releasing position.

The external lubricant spray device8initially moves from the retreating position to the upper punch spray position and to the lower punch spray position to spray an external lubricant to the lower end surface of the upper punch7as well as to the upper end surface of the lower punch6and the interior of the die bore12. This process is similar to that in the above method of producing an orally disintegrating tablet.

The conveyance member21of the feeder2A subsequently proceeds from the retreating position to the filling position and fills the die bore12with the powdery material of the feeder2A. When the conveyance member21of the feeder2A then moves from the filling position to the retreating position, the leveling plate212at the lower surface of the conveyance member21levels and removes a powdery material overflown from the upper edge of the die bore12.

The upper punch7subsequently descends and the lower end thereof is inserted to the die bore12. The lower end of the upper punch7and the upper end of the lower punch6compress the powdery material in the die bore12(e.g., preliminary compression). Therefore, a first layer (lower layer) of the double layer tablet is molded.

The driver31, the dust collecting case32engaged with the driver31, and the suction duct33connected to the dust collecting case32descend along with the descending upper punch7, and the dust collecting case32moves to the dust collecting position. The lower end surfaces of the side walls322of the dust collecting case32located at the dust collecting position are in close contact with the upper surface of the die table1. In this state, the ejector generates suction force to decompress the internal space323of the dust collecting case32, so as to suck dust and dirt including a powdery material remaining in the region around the die bore12on the upper surface of the die table1.

The upper punch7, the driver31, the dust collecting case32, and the suction duct33subsequently ascend. The lower end of the upper punch7is extracted from the die bore12and the suction duct33moves to the releasing position.

The conveyance member21of the feeder2B subsequently moves from the retreating position to the filling position and fills the die bore12with the powdery material of the feeder2B.

When the conveyance member21then moves from the filling position to the retreating position, the leveling plate212at the lower surface of the conveyance member21levels and removes a powdery material overflown from the upper edge of the die bore12.

The upper punch7subsequently descends and the lower end thereof is inserted to the die bore12. The lower end of the upper punch7and the upper end of the lower punch6compress the powdery material in the die bore12(e.g., main compression, or preliminary compression and main compression). A second layer (e.g., upper layer) of the double layer tablet is thus molded to complete the double-layer tablet.

The driver31, the dust collecting case32, and the suction duct33descend along with the descending upper punch7, and the dust collecting case32are located at the dust collecting position. The lower end surfaces of the side walls322of the dust collecting case32located at the dust collecting position are in close contact with the upper surface of the die table1. In this state, the ejector generates suction force to decompress the internal space323of the dust collecting case32, so as to suck dust and dirt including a powdery material remaining in the region around the die bore12on the upper surface of the die table1.

The upper punch7, the driver31, the dust collecting case32, and the suction duct33subsequently ascend. The lower end of the upper punch7is extracted from the die bore12and the suction duct33moves to the releasing position.

The lower punch6is then ascended and the upper end thereof pushes a compression-molded product out of the die bore12onto the die table1. The feeder2A (or2B) discharges the compression-molded product.

After the first layer is molded and before the die bore12is filled with a powdery material to configure the second layer, the external lubricant spray device8can optionally spray an external lubricant to the lower end surface of the upper punch7as well as to the upper end surface of the lower punch6and the interior of the die bore12. Still optionally, a spray device configured to spray a partitioning agent partitioning between the first layer and the second layer, a binding agent binding these layers, or a dividing agent dividable between these layers can be included separately to spray such an agent to the interface between the first layer and the second layer.

The invention is not limited to the exemplary embodiments described above. The dust collecting case32is moved vertically in the above exemplary embodiment. The dust collecting case32can alternatively slide along the upper surface of the die table1similarly to the conveyance members21of the feeders2A and2B.

The compression molding machine according to the above exemplary embodiment can be modified to produce a dry-coated tablet by replacing any one of the feeders2A and2B with a core supplier configured to supply the die bore12with a core (e.g., an internal core or a core tablet) to be buried in the dry-coated tablet.

Specific configurations of the other portions can be modified in various manners within the scope not departing from the purposes of the invention. The spray device according to the invention is applicable to a single-stroke compression molding machine as well as to a rotary compression molding machine.