Provided is a coagulation method for a liquid, recovered from a printer, and containing pigment and a cleaning liquid. The coagulation method includes storing the recovered liquid containing the pigment and the cleaning liquid, cooling the recovered liquid such that at least a part of the recovered liquid solidifies, and heating a solid generated by solidifying at least a part of the recovered liquid in order to liquefy the solid.

The present application is based on, and claims priority from JP Application Serial Number 2021-045651, filed Mar. 19, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a coagulation method, a coagulation device, and an ejecting device.

2. Related Art

In a transport belt cleaning method described in JP 2004-136534 A, by electrolyzing a cleaning liquid used for cleaning a medium to be cleaned, ink in the cleaning liquid is decomposed into dye and the cleaning liquid.

In the method described in JP 2004-136534 A, although dye is used for ink, no consideration is given, in a case of using ink containing pigment, to separation of the pigment. Here, ink containing pigment is used in an inkjet printer, and when a transport unit of a medium is soiled with the ink, the ink is removed by cleaning using a cleaning liquid. However, a method for separating pigment from cleaning liquid containing the pigment has not been established.

SUMMARY

In order to solve the problems described above, a coagulation method according to the present disclosure is a coagulation method for a liquid containing pigment and a cleaning liquid recovered from a liquid ejecting device, the method including storing the liquid, cooling the liquid such that at least a part of the liquid solidifies, and heating a solid generated by solidifying at least a part of the liquid in order to liquefy the solid.

A coagulation device according to the present disclosure is a coagulation device for performing coagulation treatment for a liquid containing pigment and a cleaning liquid recovered from a liquid ejecting device, the coagulation device including a storage unit configured to store a liquid containing the pigment and the cleaning liquid, and a temperature change unit configured to change a temperature of the liquid stored in the storage unit, wherein the temperature change unit cools the liquid such that at least a part of the liquid solidifies, and heats a solid generated by solidifying at least a part of the liquid in order to liquefy the solid.

An ejecting device according to the present disclosure includes a transport unit configured to transport a medium, an ejecting unit configured to eject a composition containing pigment onto the medium, a cleaner unit configured to clean, with a cleaning liquid, the transport unit to which the composition adheres, a storage unit configured to store a liquid containing the pigment and the cleaning liquid, and a temperature change unit configured to change a temperature of the liquid stored in the storage unit, wherein the temperature change unit cools the liquid such that the liquid solidifies, and heats a solid generated by solidifying the liquid in order to liquefy the solid.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, the present disclosure will be schematically described.

A coagulation method according to a first aspect of the present disclosure is a coagulation method for a liquid containing pigment and a cleaning liquid recovered from a liquid ejecting device, the method including storing the liquid, cooling the liquid such that at least a part of the liquid solidifies, and heating a solid generated by solidifying at least a part of the liquid in order to liquefy the solid.

According to the present aspect, for example, the pigment is dispersed in the liquid after being used to clean a transport unit, as an element to be cleaned by the cleaning liquid. Furthermore, since the dispersed pigment coagulates, the pigment is easily recovered. This makes it easier to separate the cleaning liquid component from the liquid, making it easier to reuse the cleaning liquid for cleaning the transport unit. Note that, an element cleaned by a cleaning liquid is not particularly limited as long as the element is an element to which pigment can adhere in accordance with operation of a liquid ejecting device, and configures the liquid ejecting device.

A coagulation device according to a second aspect is a coagulation device for performing coagulation treatment for a liquid containing pigment and a cleaning liquid recovered from a liquid ejecting device, the coagulation device including a storage unit configured to store the liquid containing the pigment and the cleaning liquid, and a temperature change unit configured to change a temperature of a liquid stored in the storage unit, wherein the temperature change unit is configured to cool the liquid such that at least a part of the liquid solidifies, and heat a solid generated by solidifying at least a part of the liquid in order to liquefy the solid.

According to the present aspect, the pigment is dispersed in the liquid, which is the cleaning liquid, after being used to clean the transport unit. Furthermore, since the dispersed pigment coagulates, the pigment is easily recovered. This makes it easier to separate the cleaning liquid component from the liquid, making it easier to reuse the cleaning liquid for cleaning the transport unit.

A coagulation device according to a third aspect is the coagulation device according to the second aspect including a filtration unit configured to filter a mixture generated by heating the solid.

Mixtures include both a mixture that is composed entirely and solely of liquid, and a mixture in which a part is liquid and a remaining part is a solid.

According to the present aspect, a liquid after removing components of the pigment from the mixture using the filtration unit can be reused as the cleaning liquid for cleaning the transport unit.

A coagulation device according to a fourth aspect is the coagulation device according to the second aspect or the third aspect including a centrifugation unit configured to perform centrifugation to separate the pigment from a mixture generated by heating the solid.

According to the present aspect, by efficiently removing the pigment from the mixture using the centrifugation unit, the liquid after removing the components of the pigment from the mixture can be reused as the cleaning liquid for cleaning the transport unit.

A coagulation device according to a fifth aspect is the coagulation device according to any one of the second aspect to the fourth aspect including, when the storage unit is a first storage unit, a second storage unit configured to store the liquid, when the temperature change unit that changes a temperature of the liquid stored in the first storage unit is a first temperature change unit, a second temperature change unit configured to change a temperature of the liquid stored in the second storage unit, and a control unit configured to control operation of the first temperature change unit and operation of the second temperature change unit, wherein the second temperature change unit is capable of discharging heat to the first storage unit when the liquid is cooled, the control unit, after causing the first temperature change unit to solidify the liquid stored in the first storage unit, causes the first temperature change unit to stop operation of cooling the liquid stored in the first storage unit, and after the operation of cooling the liquid stored in the first storage unit by the first temperature change unit is stopped, performs control such that the second temperature change unit cools the liquid stored in the second storage unit while discharging heat to the first storage unit.

According to the present aspect, a solidified solid in the first storage unit can be restored to liquid, by using discharged heat from the second temperature change unit without heating using the first temperature change unit.

An ejecting device according to a sixth aspect includes a transport unit configured to transport a medium, an ejecting unit configured to eject a composition containing pigment onto the medium, a cleaner unit configured to clean, with a cleaning liquid, the transport unit to which the composition adheres, a storage unit configured to store a liquid containing the pigment and the cleaning liquid, and a temperature change unit configured to change a temperature of the liquid stored in the storage unit, wherein the temperature change unit is configured to cool the liquid such that the liquid solidifies, and heat a solid generated by solidifying the liquid in order to liquefy the solid.

According to the present aspect, since the dispersed pigment is coagulated, the pigment is easily recovered. This makes it easier to separate the cleaning liquid component from the liquid, making it easier to reuse the cleaning liquid for cleaning the transport unit.

Furthermore, since the pigment is easily separated from the liquid, it is possible to suppress a reduction in cleaning performance of the transport unit, when the cleaning liquid is reused.

Hereinafter, a coagulation method, a coagulation unit60, and a printer10according to Exemplary Embodiment 1 of the present disclosure will be described in detail.

FIG.1illustrates an overall configuration of the printer10.

The printer10is an example of an ejecting device, and performs recording on a sheet P, which is an example of a medium. Other examples of the medium include fiber. Note that, an X-Y-Z coordinate system illustrated in each figure is an orthogonal coordinate system.

An X direction is a device width direction of the printer10, and as an example, is a horizontal direction. A tip side of an arrow indicating a direction is defined as a +X direction, and a base end side of the arrow indicating the direction is defined as a −X direction. Furthermore, the X direction is an example of a width direction of the sheet P and a width direction of a glue belt26described below.

A Y direction is a depth direction of the printer10, and is the horizontal direction. The Y direction is orthogonal to the X direction. A tip side of an arrow indicating a direction is defined as a +Y direction, and a base end side of the arrow indicating the direction is defined as a −Y direction. The +Y direction is also an example of a transport direction in which the sheet P is transported.

A Z direction is along a gravitational direction in which gravity acts. A tip side of an arrow indicating a direction is defined as a +Z direction, and a base end side of the arrow indicating the direction is defined as a −Z direction. The +Z direction is a device height direction of the printer10, and is orthogonal to both the Y direction and the X direction.

The printer10includes, as an example, a body frame (not illustrated), a transporting unit20, a record unit30, a cleaning unit40, a controlling unit50, a power source52, and the coagulation unit60.

The transporting unit20is provided at the body frame. In particular, the transporting unit20includes a driving roller22, a driven roller24, the glue belt26, and a motor (not illustrated). Then, the transporting unit20transports the sheet P supported by the glue belt26in the +Y direction, in accordance with movement of the glue belt26by rotation of the driving roller22. In the +Y direction, the driving roller22is disposed downstream the driven roller24. In addition, both the driving roller22and the driven roller24include a rotary shaft in the X direction. Rotation of the driving roller22is controlled by the controlling unit50described below controlling operation of the motor.

The glue belt26is an example of a transport unit, and transports the sheet P in the +Y direction. The glue belt26is configured as an endless belt obtained by joining both ends of a planar plate having elasticity. Further, the glue belt26is wound around an outer circumferential surface of the driving roller22and an outer circumferential surface of the driven roller24. In other words, the glue belt26is capable of transporting the sheet P by being cycled.

As an example, a front surface27of the glue belt26has adhesiveness, and is capable of supporting and adsorbing the sheet P. The adhesiveness refers to a property that makes temporarily bonding with another member and peeling in a bonded state possible.

The record unit30is an example of a recording unit. Furthermore, the record unit30is capable of recording information on the sheet P transported in the +Y direction. Specifically, the record unit30includes a recording head32, which is an example of an ejecting unit, and a carriage34that supports the recording head32so that reciprocating movement is possible along the X direction. Also, the record unit30is disposed above the glue belt26.

The recording head32has a plurality of nozzles (not illustrated), and is disposed in the +Z direction with respect to the front surface27. Additionally, the recording head32can perform recording on the sheet P by ejecting ink Q from the plurality of nozzles onto a recording surface of the sheet P.

The ink Q is an example of a composition. The ink Q includes a black ink, and color inks different from the black ink. Examples of colors of the color ink include yellow, cyan, and magenta. Specifically, the ink Q includes a pigment G (FIG.3) as a color material, a solvent for ensuring ejection stability and preservation stability of ink, a surfactant, a pH adjusting agent, a preservative, and an anti-mold agent. Note that, in the present exemplary embodiment, the pigment G of the black ink is used, as an example.

As the pigment G, both of an inorganic pigment and an organic pigment can be used. The inorganic pigment is not particularly limited, and examples thereof include carbon black, iron oxide, titanium oxide, and silica oxide, for example.

The cleaning unit40is an example of a cleaner unit. The cleaning unit40is disposed at a predetermined position in the −Z direction with respect to the glue belt26. Specifically, the cleaning unit40includes a cleaning tank42and a cleaning brush44.

The cleaning tank42is disposed in a state of opening in the +Z direction. An outflow pipe43is coupled to a bottom of the cleaning tank42. A valve (not illustrated) is provided at the outflow pipe43so as to be able to open and close.

In the cleaning tank42, a cleaning liquid C is stored. For example, the cleaning liquid C is formed of water or an organic solvent. Note that, the cleaning liquid C may contain additives such as surfactants as necessary.

The cleaning brush44is rotatable about a central axis along the X direction, provides the cleaning liquid C to the front surface27in accordance with rotation while recovering the ink Q on the front surface27.

In this way, the cleaning unit40cleans the front surface27of the glue belt26to which the ink Q adheres with the cleaning liquid C.

Here, a liquid containing the pigment G and the cleaning liquid C is referred to as a recovered liquid K. The recovered liquid K is an example of a liquid containing the pigment G and the cleaning liquid C. Note that, a recovered liquid before a temperature thereof is changed by a temperature change unit80described below is referred to as the recovered liquid K, and a recovered liquid after the temperature thereof is changed by the temperature change unit80is referred to as a mixture M (FIG.4), and the two are distinguished. Chemical composition of the mixture M is the same as chemical composition of the recovered liquid K. However, the chemical composition of the mixture M may be different from the chemical composition of the recovered liquid K. For example, the chemical composition of the recovered liquid K changes during a process of heating the recovered liquid K, and as a result, the chemical composition of the mixture M may be different from the chemical composition of the recovered liquid K.

The controlling unit50is configured to include a central processing unit (CPU) (not illustrated), a read only memory (ROM), a random access memory (RAM), and a storage (not illustrated), and controls operation of each unit of the printer10.

The power source52is controlled by the controlling unit50, and is capable of powering each unit of the printer10. A part of power of the power source52is used for operation of the temperature change unit80described below.

The coagulation unit60is an example of a coagulation device for coagulating pigments G from the recovered liquid K. The coagulation unit60includes a storage unit70and the temperature change unit80. The coagulation unit60performs coagulation treatment. The coagulation treatment includes treatment for storing the recovered liquid K, treatment for cooling the recovered liquid K such that at least a part of the recovered liquid solidifies, and treatment for heating a solid S (FIG.3) such that the solid S generated by solidifying at least a part of the recovered liquid K liquefies. Note that, the solid S will be described below.

The storage unit70has a reservoir72, as an example. The reservoir72is open in the +Z direction, and is disposed in the −Z direction with respect to the cleaning tank42. The reservoir72stores the recovered liquid K flowing from the cleaning tank42through the outflow pipe43.

Note that, the cleaning unit40and the storage unit70are supported by a sliding unit (not illustrated), and the sliding unit is moved in the X direction, thereby allowing extraction from the body frame or storage in the body frame.

As an example, the temperature change unit80includes the power source52, a cooling unit82, and a heating unit86. As an example, operation of the temperature change unit80is controlled by the controlling unit50to change a temperature of the recovered liquid K stored in the storage unit70.

The cooling unit82includes, as an example, a cooling plate84that is constituted by a Peltier element and to which a heat sink (not illustrated) is attached. The cooling plate84is attached to a side portion of the reservoir72, as an example. When the power source52energizes the cooling plate84, the cooling unit82cools the reservoir72. Note that, the cooling unit82can cool an inside of the reservoir72to a temperature lower than 0° C. A material constituting the reservoir72may be metal such as iron, stainless steel, or aluminum.

The heating unit86includes, as an example, a heating plate88formed of a planar heating element attached to a bottom of the reservoir72. When the power source52energizes the heating plate88, the heating unit86heats the reservoir72. The heating unit86heats the frozen or solidified recovered liquid K by the cooling unit82so as to melt, and changes a state thereof to the mixture M. Note that, the frozen recovered liquid K is referred to as the solid S (FIG.3).

In this way, the temperature change unit80cools the recovered liquid K such that at least a part of the recovered liquid K solidifies. Furthermore, the temperature change unit80heats the solid S such that the solid S generated by solidifying at least a part of the recovered liquid K liquefies.

Next, an action of the coagulation method, the coagulation unit60, and the printer10according to Exemplary Embodiment 1 will be described.

As illustrated inFIG.1, after recording is performed by the record unit30on the sheet P to be transported, a part of the ink Q may adhere to the front surface27of the glue belt26. For example, this applies to a case where marginless recording is performed on the sheet P, and the like. A part of the ink Q adhering to the front surface27is cleaned in the cleaning unit40, recovered in the cleaning tank42together with the cleaning liquid C, and becomes the recovered liquid K. Then, by opening the valve (not illustrated), the recovered liquid K flows from the cleaning tank42to the reservoir72, and is stored in the reservoir72.

As illustrated inFIG.2andFIG.3, in a state where the recovered liquid K is stored in the reservoir72, the cooling unit82is energized by the power source52(FIG.1). A temperature of the cooling plate84is decreased due to a Peltier effect. As a result, a temperature of the recovered liquid K is decreased such that at least a part of the stored recovered liquid K solidifies. As a result, the stored recovered liquid K solidifies. Arrows in the figure represent heat movement. Since the heating unit86is not energized while the cooling unit82cools the recovered liquid K, heating is not performed.

Note that, when the recovered liquid K was observed during solidification, an outer edge part of the recovered liquid K was brought into a state of being close to transparent, and a state in which the pigments G (FIG.3) collect inside the recovered liquid K was seen. The outer edge part of the recovered liquid K is a part where solidification is started earlier in time compared to an inside of the recovered liquid K, and includes a part of the recovered liquid K that comes into contact with an inner wall of the reservoir72.

As illustrated inFIG.3, the pigments G coagulate in the solid S generated by solidifying the recovered liquid K. Note that, the pigments G are illustrated as a plurality of quadrangles to facilitate understanding of the pigments G, but are actually aggregate that is close to a mass.

The pigments G, in a state of being dispersed in the ink Q (FIG.1), are kept so as not to coagulate due to differences in ionization tendency. In other words, the pigments G are in a state of being coated with what is positively or negatively charged, and repulsive force acts on the pigments G. Here, when frozen, the coating of the pigments G is in a state of being removed, so it is assumed that the repulsive force is unlikely to act on the pigments G, and the pigments G coagulate.

In a state where the cooling by the cooling unit82is stopped, and the solid S is accommodated in the reservoir72, the heating unit86is energized by the power source52to start heating of the solid S.

As illustrated inFIG.3andFIG.4, the solid S is melted by being heated by the heating unit86such that the solid S liquefies. This generates the mixture M. In accordance with the generation of the mixture M, the heating by the heating unit86is stopped.

FIG.5illustrates a state in which the temperature change unit80is removed from the reservoir72. When the mixture M is left alone, the pigments G precipitate, thereby separating a lower layer M1 containing a large amount of the pigments G, and an upper layer M2 containing a large amount of the cleaning liquids C. Here, an outflow port73is provided in a part of the reservoir72to effuse the upper layer M2, which is a supernatant, and recover the upper layer M2 in a container (not illustrated). Most of the supernatant recovered in the container is composed of the cleaning liquid C.

As illustrated inFIG.6, the pigments G are recovered from the reservoir72in which the pigments G precipitate. In this way, in the coagulation unit60of Exemplary Embodiment 1, each of the cleaning liquid C and the pigments G can be recovered by using a sedimentation method, as an example.

As described above, according to the coagulation method and the coagulation unit60of Exemplary Embodiment 1, the pigments G disperse in the recovered liquid K after being used in the cleaning of the glue belt26(FIG.1). Furthermore, by coagulating the dispersed pigments G, the pigments G are easily recovered. This makes it easier to separate the cleaning liquid C component from the recovered liquid K, making it possible to facilitate the reuse of the cleaning liquid C for cleaning of the glue belt26.

According to the printer10, the pigments G are easily separated from the recovered liquid K, thus it is possible to suppress a reduction in cleaning performance of the glue belt26, when the cleaning liquid C is reused.

Modified Example 1 of Exemplary Embodiment 1

Next, a coagulation method, the coagulation unit60, and the printer10according to Modified Example 1 of Exemplary Embodiment 1 will be described in detail. Note that, parts common to those of the coagulation method, the coagulation unit60, and the printer10according to Exemplary Embodiment 1 are denoted by the same reference signs, and descriptions thereof will be omitted.

The coagulation method, the coagulation unit60, and the printer10of Modified Example 1 are substantially the same as those of Exemplary Embodiment 1, but a method of recovering the pigments G from the solid S is different from that of Exemplary Embodiment 1.

FIG.7illustrates a state in which the solid S obtained by the coagulation method of Exemplary Embodiment 1 is cut by a cutting machine89. When the solid S is generated by cooling the recovered liquid K, points of time at which a plurality of parts of the recovered liquid K solidify differ from each other, so concentration of the pigments G in each part is not even. Many of the pigments G collect, rather than in an outer edge of the solid S, in an inside where solidification occurs later. A central portion SA in which these pigments G collect is cut into a cuboid shape by the cutting machine89, as an example. Note that, of the solid S, a remaining part except the central portion SA is referred to as a remaining portion SB.

In the central portion SA, a mixing ratio of the pigments G is greater compared to the remaining portion SB. Thus, the central portion SA as is can be discarded as the pigments G.

The remaining portion SB has a small amount of the pigments G. Thus, as an example, by melting and leaving alone the remaining portion SB to precipitate the remaining pigments G, it is possible to recover the cleaning liquid C becoming the supernatant.

There is such a method for recovering the pigments G by cutting the coagulated pigments G from the solid S.

Modified Example 2 of Exemplary Embodiment 1

Next, a coagulation method, the coagulation unit60, and the printer10according to Modified Example 2 of Exemplary Embodiment 1 will be described in detail. Note that, parts common to those of the coagulation method, the coagulation unit60, and the printer10according to Exemplary Embodiment 1 are denoted by the same reference signs, and descriptions thereof will be omitted.

The coagulation method, the coagulation unit60, and the printer10of Modified Example 2 are substantially the same as those of Exemplary Embodiment 1, but a method of recovering the pigments G from the solid S is different from those of Exemplary Embodiment 1 and Modified Example 1.

FIG.8illustrates a state in which the solid S (FIG.3) obtained by the coagulation method of Exemplary Embodiment 1 is pulverized by a pulverizer (not illustrated), and then screened out. Note that, the solid S is pulverized in advance into a plurality of chips each having a size that does not melt during the screening.

Here, a chip containing the pigments G the most is referred to as a chip A, a chip having a lower mixing ratio of the pigments G compared to the chip A is referred to a chip B, and a chip having a lower mixing ratio of the pigments G compared to the chip B is referred to as a chip C. Note that, the chip A, the chip B, and the chip C illustrated inFIG.8are partially extracted, and are illustrated with the mixing ratios different from actual mixing ratios. In addition, the mixing ratio is, for example, a ratio of volume of the pigments G contained in a single chip with respect to volume of the single chip.

The chip A, the chip B, and the chip C are screened out by a screening device90, as an example.

The screening device90includes an identification unit92that is capable of identifying the chip A, the chip B, and the chip C, and a separation unit94that separates the chip A from the chip B and the chip C, among the chip A, the chip B, and the chip C identified in the identification unit92.

The identification unit92is configured to include, for example, a camera that performs identification using near infrared rays.

The separation unit94is configured to include an air nozzle (not illustrated). In addition, the separation unit94blows off the chip B and the chip C detected by the identification unit92using air. On the other hand, the chip A falls due to its own weight. As a result, the chip A is separated. There is such a method for recovering a part containing a large amount of the pigments G by pulverizing and screening the solid S.

Next, a coagulation method, a coagulation unit100, and the printer10according to Exemplary Embodiment 2 will be specifically described. Note that, parts common to those of the coagulation method, the coagulation unit60, and the printer10according to Exemplary Embodiment 1 are denoted by the same reference signs, and descriptions thereof will be omitted. Exemplary Embodiment 2 is different in that the coagulation unit100is used in the printer10instead of the coagulation unit60.

As illustrated inFIG.9, the coagulation unit100includes a storage unit102, a temperature change unit104, a separation unit110, and a recovery tank116.

The storage unit102has the reservoir72. A supply pipe103is coupled to a bottom of the reservoir72.

The temperature change unit104includes a cooler unit106and a heater unit108.

Since a Peltier effect is generated by energization by the power source52(FIG.1), the cooler unit106cools the reservoir72and solidifies the recovered liquid K inside the reservoir72.

The heater unit108is energized by the power source52and heats the reservoir72to melt or liquefy the solid S (FIG.3) inside the reservoir72.

The separation unit110is coupled to an inside of the reservoir72via the supply pipe103. The supply pipe103is provided with a supply pump105. Also, as an example, the separation unit110includes a filtration unit112and a centrifugation unit114.

The filtration unit112is configured to include a filter (not illustrated). In addition, the filtration unit112filters the mixture M generated by the solid S generated in the storage unit102being heated by the temperature change unit104.

The centrifugation unit114performs centrifugation to separate the pigments G from the mixture M.

Note that, in the separation unit110, the centrifugation is performed by the centrifugation unit114for the mixture M after the filtration is performed in the filtration unit112.

An inside of the recovery tank116is coupled to the separation unit110via a discharge pipe117. The discharge pipe117is provided with a discharge pump118. Liquid approximately close to the cleaning liquid C after the pigments G are separated in the separation unit110is stored inside the recovery tank116.

Next, an action of the coagulation method, the coagulation unit100, and the printer10of Exemplary Embodiment 2 will be described.

In the coagulation unit100, the cooler unit106is energized by the power source52to solidify the recovered liquid K inside the reservoir72. This causes the pigments G to coagulate in a central portion of the solid S (FIG.3). Then, the energizing the cooler unit106is stopped.

Subsequently, the heater unit108heats the solid S by being energized by the power source52. As a result, the mixture M is generated inside the reservoir72. Then, the energizing the heater unit108is stopped.

The supply pump105is driven to supply the mixture M inside the reservoir72to the separation unit110.

In the separation unit110, the filtration unit112separates the pigments G by filtering the mixture M.

Subsequently, the centrifugation unit114further separates the pigments G by performing centrifugation for the mixture M containing a part of the remaining pigments G.

The discharge pump118is driven to discharge the cleaning liquid C separated from the pigments G in the separation unit110into the recovery tank116.

As described above, according to the coagulation method, the coagulation unit100, and the printer10of Exemplary Embodiment 2, a liquid after components of the pigments G are removed from the mixture M using the filtration unit112can be reused as the cleaning liquid C for cleaning the glue belt26.

In addition, by efficiently removing the pigments G from the mixture M using the centrifugation unit114, a liquid after component of the pigments G are removed from the mixture M can be reused as the cleaning liquid C for cleaning the glue belt26. In addition, compared to a sedimentation method, a time for removing the components of the pigments G from the mixture M can be shortened.

Next, a coagulation method, a coagulation unit120, and the printer10according to Exemplary Embodiment 3 will be specifically described. Note that, parts common to those of the coagulation method, the coagulation unit60, and the printer10according to Exemplary Embodiment 1 are denoted by the same reference signs, and descriptions thereof will be omitted.

Exemplary Embodiment 3 is different in that the coagulation unit120is used in the printer10instead of the coagulation unit60.

As illustrated inFIG.10, the coagulation unit120includes a storage unit122, a temperature change unit132, the controlling unit50, and the power source52. The controlling unit50in Exemplary Embodiment 3 is an example of a control unit.

The storage unit122includes, as an example, a reservoir123, a reservoir124, and a reservoir125. The reservoir123is an example of a first storage unit. The reservoir124is an example of a second storage unit with respect to the reservoir123. In addition, the reservoir124is also an example of the first storage unit with respect to the reservoir125. The reservoir125is an example of a third storage unit. In addition, when the reservoir124is regarded as the first storage unit with respect to the reservoir125, the reservoir125is also an example of the second storage unit.

The reservoir124is located downstream the reservoir123in the +Y direction. The reservoir125is located downstream the reservoir124in the +Y direction. The reservoirs123,124, and125are each capable of storing the recovered liquid K.

The reservoir123and the reservoir124are partitioned by a partition wall126that stands upright in the +Z direction. The reservoir124and the reservoir125are partitioned by a partition wall127that stands upright in the +Z direction. A height of the partition wall126in the +Z direction and a height of the partition wall127in the +Z direction are approximately the same height, as an example. The partition wall126and the partition wall127also include, as an example, components of aluminum.

A drain pipe128is provided at a predetermined location in the +Z direction with respect to the reservoir125. The recovered liquid K recovered after cleaning the glue belt26(FIG.1) flows from the drain pipe128to the reservoir125only. The recovered liquid K contains the pigments G (FIG.3).

When the reservoir125is full, the recovered liquid K overflowing from the reservoir125flows into the reservoir124. When the reservoir124is full, the recovered liquid K overflowing from the reservoir124flows into the reservoir123. In this manner, the recovered liquid K is stored in an order of the reservoir125, the reservoir124, and the reservoir123.

The temperature change unit132includes a temperature changing unit134for changing a temperature of the recovered liquid K stored in the reservoir123, a temperature changing unit137for changing a temperature of the recovered liquid K stored in the reservoir124, and a temperature changing unit142for changing a temperature of the recovered liquid K stored in the reservoir125.

The temperature changing unit134is an example of a first temperature change unit. Specifically, the temperature changing unit134is constituted by an endothermic plate135, a heat dissipating plate136, and a Peltier element (not illustrated). The Peltier element is sandwiched between the endothermic plate135and the heat dissipating plate136, and is energized by the power source52to generate a Peltier effect. The heat dissipating plate136is attached to a side wall in the −Y direction of the reservoir123. The endothermic plate135is exposed to an inside of the reservoir123.

The temperature changing unit137is an example of a second temperature change unit. Note that, the temperature changing unit137is also an example of the first temperature change unit. The temperature changing unit137is capable of discharging heat to the reservoir123, when cooling the recovered liquid K in the reservoir124. Specifically, the temperature changing unit137is constituted by an endothermic plate138, a heat dissipating plate139, and a Peltier element (not illustrated). The Peltier element is sandwiched between the endothermic plate138and the heat dissipating plate139, and is energized by the power source52to generate a Peltier effect. The heat dissipating plate139is attached to a surface in the +Y direction of the partition wall126. The endothermic plate138is exposed to an inside of the reservoir124.

The temperature changing unit142is an example of a third temperature change unit. Note that, when the temperature changing unit137is regarded as the first temperature change unit, the temperature changing unit142is also an example of the second temperature change unit. The temperature changing unit142is capable of discharging heat to the reservoir124, when the recovered liquid K is cooled in the reservoir125. Specifically, the temperature changing unit142is constituted by an endothermic plate143, a heat dissipating plate144, and a Peltier element (not illustrated). The Peltier element is sandwiched between the endothermic plate143and the heat dissipating plate144, and is energized by the power source52to generate a Peltier effect. The heat dissipating plate144is attached to a surface in the +Y direction of the partition wall127. The endothermic plate143is exposed to an inside of the reservoir125.

Note that, the endothermic plates135,138, and143, and the heat dissipating plates136,139, and144may be made of metal, a thermally conductive ceramic, or the like.

Additionally, the endothermic plate138, the heat dissipating plate139, and the partition wall126are an example of members constituting a heat transfer path between the reservoir123and the reservoir124. The endothermic plate143, the heat dissipating plate144, and the partition wall127are an example of members constituting a heat transfer path between the reservoir124and the reservoir125. In other words, the coagulation unit120and the printer10have a heat transfer unit that transfers heat discharged from the second temperature change unit to the first storage unit. Here, for the heat transfer unit, a thermal conduction method need not be adopted in which a plurality of members are combined as in the present exemplary embodiment. For example, a thermal conduction method with a single member may be used. Further, the heat discharged from the second temperature change unit may be transferred to the first storage unit by radiation, convection generated by flowing air, or the like.

The controlling unit50controls operation of the temperature changing units134,137, and142. In addition, the controlling unit50causes the temperature changing unit134to stop the operation, after causing the temperature changing unit134to solidify the recovered liquid K stored in the reservoir123. Furthermore, after the operation of the temperature changing unit134is stopped, the controlling unit50performs control to cause the reservoir123to be heated by heat discharged from the temperature changing unit137.

The controlling unit50causes the temperature changing unit137to stop the operation, after causing the temperature changing unit137to solidify the recovered liquid K stored in the reservoir124. Furthermore, after the operation of the temperature changing unit137is stopped, the controlling unit50performs control to cause the reservoir124to be heated by heat discharged from the temperature changing unit142.

In other words, the controlling unit50causes the temperature changing unit134to stop the operation for cooling the recovered liquid K stored in the reservoir123, after causing the temperature changing unit134to solidify the recovered liquid K stored in the reservoir123, and after the operation of the temperature changing unit134for cooling the recovered liquid K stored in the reservoir123is stopped, performs control such that the temperature changing unit137cools the recovered liquid K stored in the reservoir124while discharging heat to the reservoir123. Note that, the controlling unit50may perform control such that the temperature changing unit134heats the solid S in the reservoir123, when the temperature changing unit137cools the recovered liquid K stored in the reservoir124while discharging heat to the reservoir123. In addition, the controlling unit50may perform control to cause the temperature changing unit134to completely stop the operation, when the temperature changing unit137cools the recovered liquid K stored in the reservoir124while discharging heat to the reservoir123.

The controlling unit50causes the temperature changing unit137to stop the operation for cooling the recovered liquid K stored in the reservoir124, after causing the temperature changing unit137to solidify the recovered liquid K stored in the reservoir124, and after the operation of the temperature changing unit137for cooling the recovered liquid K stored in the reservoir124is stopped, performs control such that the temperature changing unit142cools the recovered liquid K stored in the reservoir125while discharging heat to the reservoir124. Note that, the controlling unit50may perform control such that the temperature changing unit137heats the solid S in the reservoir124, when the temperature changing unit142cools the recovered liquid K stored in the reservoir125while discharging heat to the reservoir124. In addition, the controlling unit50may perform control to cause the temperature changing unit137to completely stop the operation, when the temperature changing unit142cools the recovered liquid K stored in the reservoir125while discharging heat to the reservoir124.

Furthermore, a detector may be provided that detects a degree of solidification of the recovered liquid K stored in each of the reservoirs123,124, and125. For example, as the detector, a temperature sensor may be used. In this case, based on a detection result of the temperature sensor, the controlling unit50can determine whether the recovered liquid K stored in each of the reservoirs123,124, and125is solidified or not. Note that, a sensor unit may be used as the detector that includes a vibration piece immersed in the recovered liquid K, and an actuator that vibrates the vibration piece. In this case, when a part of the recovered liquid K that comes into contact with the vibrating piece solidifies, the vibration piece is less likely to vibrate, and a current is changed that is to be supplied to the actuator in order to cause the vibration piece to vibrate with a predetermined amplitude. Based on the change in the current supplied to the actuator, the controlling unit50can determine whether the recovered liquid K stored in each of the reservoirs123,124, and125is solidified or not.

Next, an action of the coagulation method, the coagulation unit120, and the printer10of Exemplary Embodiment 3 will be described.

A predetermined amount of the recovered liquid K is stored in each of the reservoir125, the reservoir124, and the reservoir123. Here, when the reservoir123is substantially full, the power source52energizes the temperature changing unit134. By this energization, a Peltier element (not illustrated) is operated, and thus heat is absorbed in the endothermic plate135and is dissipated in the heat dissipating plate136. As a result, a temperature of the recovered liquid K in the reservoir123is reduced, and the recovered liquid K becomes the solid S. Then, the energizing the temperature changing unit134is stopped.

Subsequently, the temperature changing unit137is energized by the power source52. By this energization, heat is absorbed in the endothermic plate138, and is dissipated in the heat dissipating plate139. As a result, a temperature of the recovered liquid K in the reservoir124is reduced, and the recovered liquid K becomes the solid S. At this time, the heat dissipated from the heat dissipating plate139moves to the solid S in the reservoir123via the partition wall126. This restores the solid S in the reservoir123to the mixture M (FIG.4). Then, the energizing the temperature changing unit137is stopped.

Subsequently, the temperature changing unit142is energized by the power source52. By this energization, heat is absorbed in the endothermic plate143, and is dissipated in the heat dissipating plate144. As a result, a temperature of the recovered liquid K in the reservoir125is reduced, and the recovered liquid K becomes the solid S. At this time, the heat dissipated from the heat dissipating plate144moves to the solid S in the reservoir124via the partition wall127. This restores the solid S in the reservoir124to the mixture M. Then, the energizing the temperature changing unit142is stopped.

As described above, according to the coagulation method, the coagulation unit120, and the printer10of Exemplary Embodiment 3, even when heating is not performed using the temperature changing units134and137, the solidified solid S in the reservoir123and124can be restored to the mixture M, which is liquid, again, by using the heat discharged from the temperature changing units137and142. This allows energy consumed by the coagulation unit120and the printer10to be reduced.

The coagulation method, the coagulation units60,100,120, and the printer10according to the exemplary embodiments of the present disclosure are based on the configuration described above. However, as a matter of course, modifications, omission, and the like may be made to a partial configuration without departing from the gist of the disclosure of the present application.

In the coagulation unit60, when an atmospheric temperature is sufficiently low, the recovered liquid K may be solidified by leaving alone the reservoir72in which the recovered liquid K is stored, in the atmosphere. In this case, power required for solidification and the like are unnecessary, and thus energy for solidifying the recovered liquid K can be reduced. In addition, when the atmospheric temperature fluctuates greatly during one day, leaving the recovered liquid K alone allows thawing after solidification.

In the coagulation unit60, when concentration of the pigments G in the recovered liquid K is high, the pigments G do not coagulate very much when the recovered liquid K is frozen in some cases. In this case, after the recovered liquid K is diluted using water or the cleaning liquid C, by solidifying the recovered liquid K, more of the pigments G can be coagulated.

When cooling by the cooling unit82is performed in the coagulation unit60, the present disclosure is not limited to a method for uniformly cooling the entire reservoir72, and the reservoir72may be partially cooled by setting a time difference.

The cooling unit82and the heating unit86may be provided at a position opposite to the reservoir72. In Modified Example 2, the pulverized chips A, B, and C may be separated not by free-fall, but while being transported using a belt conveyor.

In the coagulation unit100, the separation unit110may be constituted of only the filtration unit112or only the centrifugation unit114. Furthermore, after the centrifugation unit114is used in advance, the filtration unit112may be used.

In the coagulation unit120, the reservoir125and the temperature changing unit142need not be present. Furthermore, the number of each of the reservoirs and the temperature changing units may be four or more.

In the temperature change unit, cooling and heating may be performed by different members, respectively, or one member may have both cooling and heating functions. Furthermore, as an example of the temperature change unit, not only a temperature change unit having a cooling unit using a Peltier element, but also a temperature change unit having a heat pump may be used.

The recovered liquid K is not limited to a recovered liquid recovered from the glue belt26, and may be, for example, a recovered liquid recovered by cleaning a member different from the glue belt26, such as the recording head32.

In the cooling, both of a state in which a part of the recovered liquid K is solidified, and a state in which all of the recovered liquid K is solidified, are allowed.