An embodiment of the invention relates to a nozzle head module and an electrospinning apparatus.
There is an electrospinning apparatus in which a fine fiber is deposited on the surface of a member by electrospinning (also called electric field spinning, charge-induced spinning, etc.).
A nozzle head that ejects a source material liquid is provided in the electrospinning apparatus.
The source material liquid is attracted by an electrostatic force (a Coulomb force) acting along lines of electric force between the nozzle head and a collector. Then, the fiber is formed by the volatilization of a solvent included in the source material liquid; and the fiber that is formed is deposited on a collector and/or the member to form a deposited body.
In such a case, it has been difficult to control the deposition state of the fiber because the fiber moves through air due to the electrostatic force.
According to one embodiment, a nozzle head module includes a nozzle head having a hole electing a source material liquid, the nozzle head being configured to have a first voltage and an electrode provided to be relatively movable with respect to the nozzle head, the electrode being configured to have a second voltage. The second voltage is of the same polarity as the first voltage.
Embodiments will now be illustrated with reference to the drawings. Similar components in the drawings are marked with the same reference numerals; and a detailed description is omitted as appropriate.
Also, although a so-called needle-type nozzle head is illustrated as an example hereinbelow, the type of the nozzle head is not limited thereto. The nozzle head may be, for example, a so-called blade-type nozzle head, etc.
As shown in
The nozzle head module 1 includes a nozzle head 2 and an electric field controller 3.
The nozzle head 2 has a hole for electing the source material liquid (hereafter, first liquid). In the case of the nozzle head 2 which is a needle-type nozzle head, the hole for electing the first liquid is provided in the interior of a nozzle 20. In the case of a blade-type nozzle head, the nozzle 20 and a connector 21 are not provided; and the hole for electing the first liquid is provided in the interior of a main part 22.
The nozzle head 2 which is a needle-type nozzle head includes the nozzle 20, the connector 21, and the main part 22.
The nozzle 20 has a needle-like configuration. The hole for ejecting the first liquid is provided in the interior of the nozzle 20. The hole for ejecting the first liquid communicates between the end portion of the nozzle 20 on the connector 21 side and the end portion (the tip) of the nozzle 20 on the collector 6 side. An opening of the hole for ejecting the first liquid on the collector 6 side is an outlet 20a.
Although the outer diameter dimension (in the case where the nozzle 20 has a cylindrical configuration, the diametrical dimension) of the nozzle 20 is not particularly limited, it is favorable for the outer diameter dimension to be small. If the outer diameter dimension is set to be small, electric field concentration occurs easily at the vicinity of the outlet 20a of the nozzle 20. If the electric field concentration occurs at the vicinity of the outlet 20a of the nozzle 20, the strength of the electric field generated between the collector 6 and the nozzle 20 can be increased. Therefore, the voltage that is applied by the power supply 5 can be set to be low. In other words, the drive voltage can be reduced. In such a case, the outer diameter dimension of the nozzle 20 can be set to be, for example, about 0.3 mm to 1.3 mm.
The dimension (in the case where the outlet 20a is a circle, the diametrical dimension) of the outlet 20a is not particularly limited. The dimension of the outlet 20a can be modified appropriately according to the cross-sectional dimension of a fiber 200 to be formed. The dimension of the outlet 20a (the inner diameter dimension of the nozzle 20) can be set to be, for example, about 0.1 mm to 1 mm.
The nozzle 20 is formed from a conductive material. It is favorable for the material of the nozzle 20 to be conductive and to have resistance to the first liquid described below. For example, the nozzle 20 can be formed from stainless steel, etc.
The number of the nozzles 20 is not particularly limited and can be modified appropriately according to the size of the collector 6, etc. It is sufficient for at least one nozzle 20 to be provided.
In the case where multiple nozzles 20 are provided, the multiple nozzles 20 are provided to be arranged at a prescribed spacing. The arrangement form of the multiple nozzles 20 is not limited to the illustration. For example, in the embodiment, the multiple nozzles 20 can be provided to be arranged in one column, can be provided to be arranged on a circumference or on concentric circles, or can be provided to be arranged in a staggered configuration or a matrix configuration.
The connector 21 is provided between the nozzle 20 and the main part 22. The connector 21 is not always necessary; and the nozzle 20 may be provided directly at the main part 22. A hole for supplying the first liquid from the main part 22 to the nozzle 20 is provided in the interior of the connector 21. The hole that is provided in the interior of the connector 21 communicates with the hole provided in the interior of the nozzle 20 and the space provided in the interior of the main part 22.
The connector 21 is formed from a conductive material. It is favorable for the material of the connector 21 to be conductive and to have resistance to the first liquid. For example, the connector 21 can be formed from stainless steel, etc.
The main part 22 has a plate configuration. A space where the first liquid is stored is provided in the interior of the main part 22.
Also, a supply port 22a is provided in the main part 22. The first liquid that is supplied from the source material liquid supplier 4 is introduced to the interior of the main part 22 via the supply port 22a. The number and arrangement positions of the supply ports 22a are not particularly limited. For example, the supply port 22a can be provided on the side opposite to the side where the nozzles 20 of the main part 22 are provided.
The main part 22 is formed from a material having resistance to the first liquid. For example, the main part 22 can be formed from stainless steel, etc.
The electric field controller 3 controls the deposition state of the fiber 200 by controlling the electric field generated between the nozzle head 2 and the collector 6.
The electric field controller 3 includes the electrode 30, a holder 31, a guide 32, a movement part 33, a transmission part 34, a driving part 35, and a power supply 36.
The electrode 30 is provided on a side of the nozzle head 2 (the side of the surface of the main part 22 crossing the surface where the nozzle 20 is connected). The number of the electrodes 30 is not particularly limited. It is sufficient for at least one electrode 30 to be provided.
It is sufficient for the electrode 30 to be provided on at least one side surface side of the nozzle head 2.
However, if the number of the electrodes 30 and/or the number of the positions where the electrodes 30 are provided are increased, the variations relating to the control of the deposition state of the fiber 200 can be increased.
The position of the end portion (the tip) of the electrode 30 on the collector 6 side is not particularly limited. However, the position of the tip of the electrode 30 can be set to be the same as the position of the tip of the nozzle 20; or the position of the tip of the electrode 30 can be set to be further on the main part 22 side than is the position of the tip of the nozzle 20.
In other words, in the direction in which the hole ejecting the first liquid extends, the tip of the electrode 30 can be set to be further on the side opposite to the side where the first liquid is ejected (the direction further away from the direction in which the first liquid is ejected) than is the tip of the nozzle head 2.
Thus, as necessary, a control is performed to suppress the effects on the electric field at the periphery of the nozzle 20; and the adhesion of the first liquid drawn out from the nozzle 20 on the electrode 30, etc., also can be suppressed.
Although the configuration of the electrode 30 is not particularly limited, for example, the electrode can have a solid needle-like configuration. The electrode 30 that has the needle-like configuration extends in the direction in which the hole for ejecting the first liquid extends.
Although the outer diameter dimension of the electrode 30 having the needle-like configuration is not particularly limited, it is favorable for the outer diameter dimension to be small. If the outer diameter dimension is set to be small, electric field concentration occurs easily at the tip of the electrode 30. If the electric field concentration occurs at the tip of the electrode 30, the strength of the electric field generated between the electrode 30 and the collector 6 (or a counter electrode 37) can be increased. Therefore, the control of the deposition state of the fiber 200 described below is easy. Also, the voltage that is applied by the power supply 36 can be lower. In other words, the drive voltage can be reduced. In such a case, the outer diameter dimension of the electrode 30 can be set to be, for example, about 0.3 mm to 1.3 mm.
Also, the electrode 30 may have a tapered tip. In such a case, the outer diameter dimension of the tip can be set to be, for example, about 0.3 mm to 1.3 mm.
The electrode 30 is conductive. For example, the electrode 30 can be formed from a metal such as a copper alloy, stainless steel, etc.
The holder 31 holds the electrode 30. For example, the electrode 30 can be provided at the vicinity of one end portion of the holder 31. In the case where the power supply 36 is provided, the holder 31 can be formed from an electrically insulative material such as a resin, etc. In the case where the power supply 36 is not provided and the power supply 5 applies a voltage to the nozzle 20 and the electrode 30, the holder 31 can be formed from a conductive material such as a metal, etc. In such a case, the electrode 30 is electrically connected to the nozzle head 2.
The guide 32 is provided between the main part 22 and the holder 31. The guide 32 regulates the movement direction of the electrode 30. For example, the guide 32 can be a linear motion bearing, etc.
The movement part 33 moves the electrode 30 by the holder 31. For example, the movement part 33 can have a screw mechanism. In such a case, the movement part 33 can have a rod configuration with a left-handed thread on one end portion and a right-handed thread on the other end portion. Thus, by rotating the movement part 33 in one direction, two electrodes 30 provided to oppose can be moved in directions approaching the nozzle head 2. Also, by rotating the movement part 33 in the other direction, the two electrodes 30 provided to oppose can be moved in directions away from the nozzle head 2.
The transmission part 34 is provided between the driving part 35 and the movement part 33. The transmission part 34 transfers the driving force from the driving part 35 to the movement part 33. For example, the transmission part 34 can be a timing belt and a timing pulley, etc. It is favorable for at least a portion of the transmission part 34 to be electrically insulative and for the driving part 35 to be electrically insulated from the power supply 5 and the power supply 36. In the case illustrated in
For example, the driving part 35 can be a control motor such as a servo motor, etc.
Also, a sensor that directly or indirectly senses the position of the electrode 30, etc., can be provided appropriately.
Although the case is illustrated where the electrode 30 moves in a direction (e.g., the horizontal direction) crossing the direction in which the hole for ejecting the first liquid extends (corresponding to the direction in which the first liquid is ejected), the electrode 30 also can move in the direction (e.g., the vertical direction) in which the hole for ejecting the first liquid extends; or the electrode 30 can move in the direction in which the hole for ejecting the first liquid extends and the direction crossing the direction in which the hole for ejecting the first liquid extends.
Also, as shown in
Also, as shown in
Here, the control of the movement of the electrode 30 may be uniaxial control or may be multi-axis control.
Also, although the case is illustrated where the electrode 30 moves with respect to the nozzle head 2, the nozzle head 2 may move with respect to the electrode 30. In other words, it is sufficient for the electrode 30 to be relatively movable with respect to the nozzle head 2.
In the case where the nozzle head 2 is moved with respect to the electrode 30, it is sufficient to mount the nozzle head 2 to a not-illustrated housing of the electrospinning apparatus 100 via an electrically insulative bracket, etc., and to mount the electrode 30, the holder 31, the guide 32, the movement part 33, the transmission part 34, the driving part 35, the power supply 36, etc., to the housing via an electrically insulative bracket, etc.
If the nozzle head 2 can move with respect to the electrode 30, it becomes easy to adjust the process conditions (e.g., the distance between the nozzle head 2 and the collector 6).
On the other hand, if the electrode 30 can move with respect to the nozzle head 2, the deposition state of the fiber 200 can be controlled in a state in which the process conditions are fixed.
The power supply 36 applies a voltage to the electrode 30. In the case where the electrodes 30 are multiply provided, the power supply 36 applies the voltage to the multiple electrodes 30. The polarity of the voltage applied to the electrode 30 is the same as the polarity of the voltage applied to the nozzle 20. The power supply 36 illustrated in
Also, the power supply 36 may be able to change the voltage applied to the electrode 30. If the voltage applied to the electrode 30 can be changed, the variations relating to the control of the deposition state of the fiber 200 can be increased.
For example, the power supply 36 can be a direct current-high voltage power supply. For example, the power supply 36 can output a direct current voltage that is not less than 10 kV and not more than 100 kV.
The power supply 36 is not always necessary and can be omitted. In the case where the power supply 36 is not provided, the power supply 5 applies the voltage to the electrode 30. If the power supply 36 is omitted, the configuration of the nozzle head module 1 can be simplified; and the manufacturing cost also can be reduced. Also, if the power supply 36 is provided and the voltage applied to the electrode 30 is changed, the variations relating to the control of the deposition state of the fiber 200 can be increased.
The source material liquid supplier 4 includes a container 41, a supplier 42, a source material liquid controller 43, and a pipe 44.
The container 41 stores the first liquid. The container 41 is formed from a material having resistance to the first liquid. For example, the container 41 can be formed from stainless steel, etc.
The first liquid is a polymeric substance dissolved in a solvent.
The polymeric substance is not particularly limited and can be modified appropriately according to the material properties of the fiber 200 to be formed.
It is sufficient for the solvent to be able to dissolve the polymeric substance. The solvent can be modified appropriately according to the polymeric substance to be dissolved.
As described below, the first liquid collects at the vicinity of the outlet 20a due to surface tension. To this end, the viscosity of the first liquid can be modified appropriately according to the dimension of the outlet 20a, etc. The viscosity of the first liquid can be determined by performing experiments and/or simulations. Also, the viscosity of the first liquid can be controlled by the mixture proportion of the solvent and the polymeric substance.
The supplier 42 supplies the first liquid stored in the container 41 to the main part 22. For example, the supplier 42 can be a pump that is resistant to the first liquid, etc. Also, for example, the supplier 42 may feed the first liquid stored in the container 41 by pressurizing by supplying a gas to the container 41.
The source material liquid controller 43 controls the flow rate, pressure, etc., of the first liquid supplied to the main part 22 so that the first liquid in the interior of the main part 22 is not pushed out from the outlet 20a when new first liquid is supplied to the interior of the main part 22. The control amount for the source material liquid controller 43 can be modified appropriately using the dimension of the outlet 20a, the viscosity of the first liquid, etc. The control amount for the source material liquid controller 43 can be determined by performing experiments and/or simulations.
Also, the source material liquid controller 43 may switch between the start of the supply and the stop of the supply of the first liquid.
The supplier 42 and the source material liquid controller 43 are not always necessary. For example, if the container 41 is provided at a position that is higher than the position of the main part 22, the first liquid can be supplied to the main part 22 by utilizing gravity. Then, the first liquid that is in the interior of the main part 22 can be caused not to be pushed out from the outlet 20a when the new first liquid is supplied to the interior of the main part 22 by appropriately setting the height position of the container 41. In such a case, the height position of the container 41 can be modified appropriately using the dimension of the outlet 20a, the viscosity of the first liquid, etc. The height position of the container 41 can be determined by performing experiments and/or simulations.
The pipe 44 is provided between the container 41 and the supplier 42, between the supplier 42 and the source material liquid controller 43, and between the source material liquid controller 43 and the main part 22. The pipe 44 is used as a flow channel of the first liquid. The pipe 44 is formed from a material having resistance to the first liquid.
The power supply 5 applies the voltage to the nozzle 20 via the main part 22 and the connector 21. In other words, a voltage of a prescribed polarity is applied to the nozzle head 2. Not-illustrated terminals that are electrically connected to the multiple nozzles 20 may be provided. In such a case, the power supply 5 applies the voltage to the nozzles 20 via the not-illustrated terminals. In other words, it is sufficient for the voltage to be able to be applied to the multiple nozzles 20 from the power supply 5.
Further, in the case where the power supply 36 is not provided, the power supply 5 applies the voltage also to the electrode 30.
The polarity of the voltage applied to the nozzles 20 can be set to be positive or set to be negative. The power supply 5 illustrated in
The voltage that is applied to the nozzles 20 can be modified appropriately according to the type of the polymeric substance included in the first liquid, the distance between the collector 6 and the nozzles 20, etc. For example, the power supply 5 can apply a voltage to the nozzles 20 so that the potential difference between the collector 6 and the nozzles 20 is 10 kV or more.
For example, the power supply 5 can be a direct current-high voltage power supply. For example, the power supply 5 can output a direct current voltage that is not less than 10 kV and not more than 100 kV.
The collector 6 is provided on the side of the multiple nozzles 20 where the first liquid is ejected. The collector 6 is grounded. A voltage that has the reverse polarity of the voltage applied to the nozzles 20 may be applied to the collector 6. The collector 6 can be formed from a conductive material. It is favorable for a material of the collector 6 to be conductive and to have resistance to the first liquid. For example, the material of the collector 6 can be stainless steel, etc.
For example, the collector 6 can have a plate configuration or a sheet configuration. In the case where the collector 6 has a sheet configuration, the fiber 200 may be deposited on the collector 6 that is wound on a roll, etc.
Also, the collector 6 may be able to move. For example, a pair of rotating drums and a driving part that rotates the rotating drums may be provided; and the collector 6 that has the sheet configuration may be caused to move between the pair of rotating drums like the belt of a belt conveyor. Thus, a continuous deposition operation is possible because the region where the fiber 200 is deposited can be caused to move. Therefore, the production efficiency of a deposited body 210 made of the fiber 200 can be increased.
The deposited body 210 that is formed on the collector 6 is removed from the collector 6. For example, the deposited body 210 is used in a nonwoven cloth, a filter, etc. The applications of the deposited body 210 are not limited to those illustrated. Also, the collector 6 can be omitted. For example, the deposited body 210 that is made of the fiber 200 can be directly formed on the surface of a conductive member. In such a case, it is sufficient to ground the conductive member or to apply to the conductive member a voltage having the reverse polarity of the voltage applied to the nozzles 20.
Further, the deposited body 210 also can be formed by providing a base material on the collector 6 and by depositing the fiber 200 on the base material. Thus, the deposited body 210 can be formed even on an electrically insulative base material.
In such a case, the base material may move on the collector 6. For example, a rotating drum may be provided on which the base material having a sheet configuration is wound; a rotating drum may be provided on which the base material having the sheet configuration, on which the deposited body 210 is formed, is taken up; and the base material that has the sheet configuration may pass over the collector 6. Thus, a continuous deposition operation is possible. Therefore, the production efficiency of the deposited body 210 made of the fiber 200 can be increased.
The controller 7 controls the operations of the driving part 35, the power supply 36, the supplier 42, the source material liquid controller 43, and the power supply 5.
For example, the controller 7 can be a computer including a CPU (Central Processing Unit), memory, etc.
Further, the electrospinning apparatus 100 can further include an imaging device 8 such as a CCD camera, etc.
The imaging device 8 images the deposition state of the fiber 200 described below and transmits the image data that is imaged to the controller 7. Based on the image data that is received, the controller 7 controls the position, the movement direction, the movement velocity, the applied voltage, etc., of the electrode 30 to cause the deposition state of the fiber 200 to be a prescribed state.
The control amounts relating to the electrode 30 such as the position, the movement direction, the movement velocity, the applied voltage, etc., of the electrode 30 are affected by the process conditions such as the components of the first liquid, the voltage applied to the nozzles 20, the distance between the collector 6 and the nozzles 20, etc. Therefore, it is favorable to determine the control amounts relating to the electrode 30 by performing experiments and/or simulations.
Effects of the electrospinning apparatus 100 will now be described.
The first liquid collects at the vicinity of the outlet 20a of the nozzle 20 due to surface tension.
The power supply 5 applies a voltage to the nozzle 20. Then, the first liquid that is at the vicinity of the outlet 20a is charged with a prescribed polarity. In the case illustrated in
Here, the first liquid (the fiber 200) which is elongated reaches the collector 6 by being attracted by the electrostatic force acting along the lines of electric force between the collector 6 and the nozzle 20. Therefore, it is difficult to control the position where the fiber 200 is deposited, the deposition amount in a prescribed region, the alignment state of the deposited fiber 200, etc. In other words, the control of the deposition state of the fiber 200 is difficult.
Therefore, in the electrospinning apparatus 100 according to the embodiment, the deposition state of the fiber 200 is controlled by the electric field controller 3 controlling the electric field generated between the nozzle head 2 and the collector 6.
The electric field that is generated between the collector 6 and the nozzles 20 changes due to the effects of the electric field generated between the collector 6 and the electrodes 30.
In such a case, as described above, because a voltage having the same polarity as the voltage applied to the nozzles 20 is applied to the electrodes 30, the lines of electric force coming from the nozzles 20 toward the collector 6 and the lines of electric force coming from the electrodes 30 toward the collector 6 repel each other. In other words, the electric field that is generated between the collector 6 and the nozzles 20 is defined by the lines of electric force coming from the electrodes 30 toward the collector 6.
Therefore, in the case where the electrodes 30 are moved in the directions approaching the nozzle head 2 as shown in
On the other hand, in the case where the electrodes 30 are moved in the directions away from the nozzle head 2 as shown in
Therefore, the position where the fibers 200 are deposited, the deposition amount in the prescribed region, etc., can be controlled by controlling the movement direction of the electrodes 30, the distance between the electrodes 30 and the nozzle head 2 (the nozzles 20), the voltage applied to the electrodes 30, etc.
When the electrode 30 is moved as shown in
As described above, the position where the fiber 200 is deposited moves in the reverse direction when the electrode 30 is moved. Therefore, by repeatedly performing the back and forth movement of the electrode 30 as shown in
If the direction of the back and forth movement of one electrode 30 and the direction of the back and forth movement of another electrode 30 are different as shown in
As described above, by the electric field controller 3 controlling the electric field generated between the nozzle head 2 and the collector 6, the deposition state of the fibers 200 can be changed.
For example, as shown in
Also, as shown in
Also, as shown in
Further, a local film thickness increase and/or a local film thickness decrease, etc., also can be performed by depositing the fibers 200 and not depositing the fibers 200 at any position on the collector 6.
Further, as described above, there are also cases where a base material is provided on the collector 6, and the base material having the sheet configuration moves on the collector 6. In such a case, the deposited body 210 that has any configuration can be formed on the base material to match the configuration and/or dimensions of the base material. In other words, a local film thickness increase and/or a local film thickness decrease, etc., also can be performed by depositing the fibers 200 and not depositing the fibers 200 at any position on the base material, e.g., the base material having the sheet configuration, on the collector 6.
In such a case, the deposited body 210 that has any configuration can be formed without stopping the electrospinning apparatus 100. Also, the deposited body 210 can be formed without jutting from the collector 6 and/or the base material. Therefore, a decrease of the consumed amount of the first liquid and/or improvement of the productivity can be realized.
As shown in
The counter electrodes 37, 38a, and 38b are grounded. Also, voltages of the reverse polarity of the voltage applied to the electrodes 30 may be applied to the counter electrodes 37, 38a, and 38b by a not-illustrated power supply. In such a case, the voltages that are applied to the counter electrodes 37, 38a, and 38b are not particularly limited. However, the occurrence of electro-discharge between the collector 6 and the counter electrodes 37, 38a, and 38b can be suppressed if the voltages applied to the counter electrodes 37, 38a, and 38b and the voltage applied to the collector 6 are about the same. Also, the variations relating to the control of the deposition state of the fibers 200 can be increased by changing the voltages applied to the counter electrodes 37, 38a, and 38b.
The counter electrodes 37, 38a, and 38b can be formed from a conductive material. It is favorable for the material of the counter electrodes 37, 38a, and 38b to be conductive and to have resistance to the first liquid. For example, the material of the counter electrodes 37, 38a, and 38b can be stainless steel, etc. Also, the counter electrodes 37, 38a, and 38b can be fixed; or the counter electrodes 37, 38a, and 38b can be moveable in a prescribed direction. For example, as shown in
Also, as shown in
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions. Moreover, above-mentioned embodiments can be combined mutually and can be carried out.
Number | Date | Country | Kind |
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2016-054365 | Mar 2016 | JP | national |
This application is based upon and claims the benefit of priority from the Japanese Patent Application No. 2016-054365, filed on Mar. 17, 2016, and the PCT Patent Application PCT/JP2016/075853, filed on Sep. 2, 2016; the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/JP2016/075853 | Sep 2016 | US |
Child | 15460565 | US |