Packaging for liquid dispensing heads

Abstract

We provide packaging for liquid dispensing heads that can provide highly reliable liquid dispensing heads. [Solution] A liquid dispensing head packaging comprising a liquid dispensing head mounted on a liquid dispensing device for dispensing liquid, a humidity control agent, and packaging material for housing the liquid dispensing head and the humidity control agent.

Description

Technical Field

[0001] The present invention relates to a package of a liquid ejection head.

Background Art

[0002] A liquid ejection head that is detachably mounted on a liquid ejection device such as an inkjet printer is often packaged separately from the liquid ejection device during logistics. Also, even when a liquid ejection head is pre-installed in a recording device, a replacement liquid ejection head is packaged individually.

[0003] During logistics of the liquid ejection head, the ink flow path, particularly the nozzle leading to the ejection port, may be filled with a liquid different from the ink for normal recording. However, it is difficult to maintain a transparent liquid different from the ink under certain conditions, and it is also difficult to manage to prevent liquid leakage. For this reason, there are cases where the liquid ejection head is packaged and transported in a state where the liquid inside is completely removed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In order to avoid the influence of an environment where corrosive gas exists or an environment where dust adhesion is assumed, the liquid ejection head is generally packaged in a sealed state. However, if the head is sealed and packaged with the cleaning liquid etc. during manufacturing inside, the humidity inside the packaging material gradually rises and may eventually reach nearly 100% RH. If stored in this high humidity state for a long time during logistics etc., there is a risk of causing corrosion of metal members in the liquid ejection head, for example, contact pads made of metal on an electrical wiring board. In particular, this problem is greater in a large liquid ejection head having a complex flow path configuration.

[0006] Furthermore, in liquid dispensing heads that use a piezoelectric element as a means of applying pressure for dispensing liquid, it is known that the piezoelectric element deteriorates in the presence of moisture. Patent Document 1 discloses and proposes a piezoelectric element configuration equipped with a humidity-holding means in order to suppress the deterioration of the piezoelectric element due to moisture.

[0007] However, as shown in Reference 1, it is insufficient to address only humidity fluctuations within the piezoelectric element. For example, in the logistics environment of a print head where temperature changes are severe, it is desirable to suppress corrosion of the contact pads.

[0008] The present invention, which solves the above problems, provides a packaging for a liquid dispensing head that can provide a highly reliable liquid dispensing head. [Means for solving the problem]

[0009] A preferred packaging for a liquid dispensing head according to the present invention comprises a liquid dispensing head mounted on a liquid dispensing device for dispensing liquid, a dehumidifying agent, and a packaging material for housing the liquid dispensing head and the dehumidifying agent. [Effects of the Invention]

[0010] According to the present invention, a highly reliable liquid dispensing head can be provided. [Brief explanation of the drawing]

[0011] [Figure 1] Schematic diagram of a liquid dispensing device. [Figure 2] Perspective view of the liquid dispensing head. [Figure 3] Figure 2 shows an exploded perspective view of the liquid dispensing head. [Figure 4] Schematic cross-sectional view of the ejection element substrate. [Figure 5] A schematic perspective view showing the packaging for the liquid dispensing head of the present invention. [Figure 6]A diagram showing the change in humidity inside the packaging material under condition 1-1 of Example 1. [Figure 7] A diagram showing the change in humidity inside the packaging material under conditions 1-5 of Example 1. [Modes for carrying out the invention]

[0012] Examples of embodiments of the present invention will be described below with reference to the drawings. However, the following description is not intended to limit the scope of the present invention. As an example, the following description shows a thermal liquid dispensing head that generates bubbles using a heating element to dispense liquid, but the present invention can also be applied to liquid dispensing heads employing a piezoelectric method using a piezoelectric element and various other liquid dispensing methods.

[0013] (Configuration of the liquid dispensing device) Figure 1 is a schematic diagram of a liquid ejection device 50 equipped with a liquid ejection head 1. The liquid ejection device 50 is an inkjet device that ejects liquid such as ink from the liquid ejection head 1 onto a medium P. The liquid ejection head 1 is mounted on a carriage 53, and the carriage 53 reciprocates along the guide axis 51 in the main scanning direction indicated by arrow X. The medium P is transported by transport rollers 55, 56, 57, and 58 in the sub-scanning direction indicated by arrow Y, which intersects (orthogonal in this example) the main scanning direction.

[0014] The liquid discharge head 1 is equipped with a number of circulation units 2 corresponding to the type of liquid to be discharged, and liquid is supplied to each liquid separately. The electrical wiring, liquid and air piping necessary for liquid discharge are connected to the carriage 53 by guides 59. A cap member (not shown) is positioned outside the transport path of the medium P. When the liquid discharge head 1 is not performing a discharge operation, the cap member moves relative to the face surface of the liquid discharge head 1 to prevent the discharge port from drying out and to perform suction operations for filling and recovery.

[0015] (Configuration of the liquid dispensing head) FIG. 2 is a perspective view of the liquid ejection head 1, and FIG. 3 is an exploded perspective view of the liquid ejection head 1 shown in FIG. 2. As shown in FIG. 3, the liquid ejection head 1 has a circulation unit 2. The circulation unit 2 has a plurality of circulation units 2M, 2Y, 2K, and 2C corresponding to magenta, yellow, black, and cyan inks respectively, and each of the circulation units is connected to a flow path member 110.

[0016] Any method can be used for the connection method between the circulation unit 2 and the flow path member 110, such as a screw tightening method with a seal member sandwiched therebetween, or other connection methods by welding. A connection member 200 for receiving liquid from a liquid tank (see FIG. 1) in the liquid ejection device 50 is connected to the flow path member 110, and the connection member 200 communicates so as to be connected to each of the circulation units 2M, 2C, 2Y, and 2K.

[0017] The liquid tank and the connection member 200 are connected via supply tubes (not shown) corresponding to each ejected liquid (each ink). Each ink supplied from the supply tube passes through the connection member 200 of the flow path member 110 and is supplied to the circulation unit 2. That is, the circulation unit 2 acts as a supply unit. A discharge unit 300 is connected to the bottom surface of the flow path member 110, and the ink supplied to the circulation unit 2 is supplied to the discharge unit 300 via the flow path member 110. Also, the ink is configured to circulate between the discharge unit 300 and the circulation units 2M, 2C, 2Y, and 2K.

[0018] The discharge unit 300 has a discharge element substrate 310 provided with a discharge element (actuator) for discharging ink, a support member 320, a flexible wiring board 330 for sending an electrical signal to the discharge element, and a cover member 340 for covering the flexible wiring board 330. The discharge element substrate 310 and the flexible wiring board 330 are adhesively fixed to the support member 320. Further, when the flexible wiring board 330 is adhesively fixed, it is also disposed on both surfaces of the support member 320 where the discharge element substrate 310 is not adhered. The flexible wiring board 330 is bent along the support member 320 and then joined.

[0019] The gap between the support member 320 and the disposed flexible printed circuit board 330 is filled with an adhesive or a sealant to enhance the bonding strength and prevent a decrease in reliability due to ink intrusion.

[0020] The ejection element substrate 310 and the flexible printed circuit board 330 are electrically connected by wire bonding. Other methods such as flying lead bonding may also be used for the electrical connection. In the cover member 340, the portion corresponding to the ejection element substrate 310 is an opening. The connection method between the ejection unit 300 and the flow path member 110 may be adhesion using an adhesive or fixation by screwing with a seal member sandwiched therebetween, and any method can be used.

[0021] In the flow path member 110, the surface opposite to the surface where the connection member 200 is provided is a contact surface with the liquid ejection device main body, and an electrical wiring board 210 for receiving an electrical signal from the liquid ejection device main body is connected to the contact surface. An electrode portion (pad portion) 211 formed of the metal surface of the electrical wiring board 210 is connected to an electrode portion formed of the metal surface of the carriage 53 to obtain power and an electrical signal from the liquid ejection device main body. The obtained electrical signal or the like is sent from the electrical wiring board 210 to the ejection element substrate 310 via the flexible printed circuit board 330 up to the ejection unit 300.

[0022] Figure 4 is a cross-sectional view of the discharge element substrate 310. The discharge element substrate 310 has a substrate 11 made of a silicon substrate and a discharge port forming member 12 made of a photosensitive resin laminated together, and a lid member 20 is bonded to the back surface of the substrate 11. A discharge element 15 is formed on one side of the substrate 11, and on its back side, a liquid supply passage 18 and a liquid recovery passage 19 are formed, extending along a row of discharge ports 13. The liquid supply passage 18 and the liquid recovery passage 19, which are composed of the substrate 11 and the lid member 20, are each connected to a flow path formed in the support member 320 via an opening 22 in the lid member 20. A differential pressure is provided between the liquid supply passage 18 and the liquid recovery passage 19, and when liquid is being discharged from the discharge ports 13, this differential pressure causes liquid to flow in the discharge ports 13 that are not performing the discharge operation, as shown by arrow C in Figure 4. In other words, the liquid in the liquid supply channel 18 provided within the substrate 11 flows to the liquid recovery channel 19 via the supply port 16, pressure chamber 21, and recovery port 17.

[0023] (Print inspection process and packaging process for liquid dispensing heads) The liquid discharge head 1 has the complex liquid flow path configuration described above. Therefore, in order to confirm that liquid is discharged normally from the discharge port 13, a print (discharge) inspection is generally performed during manufacturing. When performing a print inspection, the liquid (ink) to be actually discharged or a test liquid (ink) is filled into the liquid discharge head 1 and the discharge element 15 is driven. If the liquid remains filled into the liquid discharge head 1 after the print inspection, quality problems such as leakage of the liquid, deterioration of the liquid, and deposition of colorants such as test ink onto the flow path components may occur in the subsequent logistics environment. Therefore, after removing a certain amount of the test liquid (ink) from the liquid discharge head 1, pure water or the like is filled into the liquid discharge head 1 to clean the flow path. After that, after removing a certain amount of pure water from the liquid discharge head 1, compressed dry air or the like is flowed through the flow path (air blow) to dry the flow path.

[0024] The dried liquid dispensing head 1 is placed in a head case (see Figure 5) or similar to mitigate impacts such as drops during logistics. To avoid outgassing in the logistics environment, the head case containing the liquid dispensing head 1 is placed in packaging material (pillow bag), and the packaging material is sealed by heat sealing.

[0025] (Liquid dispensing head recovery process) Depending on the frequency of use (printing frequency) of the liquid ejection unit, or due to a malfunction of the liquid ejection unit, the liquid ejection head may need to be replaced. In such cases, a service technician from the manufacturer will bring a new liquid ejection head in its packaging (100) to the user. The packaging will be opened, and the old liquid ejection head (hereinafter also referred to as the used head) will be replaced with the new one. The used head will be returned to the manufacturer in the head case (30) in which the new liquid ejection head was packaged, along with the opened packaging (31). The collected used head will then be serviced at a collection plant for reuse, for example, or its parts may be reused. For convenience, the period from when the used head is removed from the liquid ejection unit until it is returned to the plant will be referred to as the collection logistics process.

[0026] In the recovery and logistics process, the liquid dispensing head contains a certain amount of ink internally and is rarely cleaned before recovery. Depending on the type of liquid dispensed, such as ink, some release not only water vapor but also corrosive gases. Therefore, if the packaging material 31 is welded to seal the inside during the recovery and logistics process, there is a possibility that the metal parts of the liquid dispensing head, such as the contact pad, will corrode. Parts that have corroded metal cannot be reused. For this reason, to avoid the accumulation of corrosive gases and high humidity due to water vapor in a sealed state, it is conceivable to recover the product without welding the packaging material 31. On the other hand, in this case, there is a concern that ink leaking from the liquid dispensing head may leak out of the packaging material 31. There is also a concern that the head case 30 or liquid dispensing head may pop out of the packaging material 31 itself. Therefore, by partially welding the packaging material 31 and then making holes, it is possible to avoid the accumulation of corrosive gases and high humidity due to water vapor. However, even in this case, there is a possibility that corrosive gases and water vapor may accumulate inside the packaging material 31. Thus, the same challenges can exist in the recovery and logistics process as in the logistics of new liquid dispensing heads.

[0027] Figure 5 is a schematic perspective view of the packaging 100 for the liquid dispensing head in this embodiment. The packaging 100 includes a liquid dispensing head 1, a humidity control agent 32, and packaging material for housing the liquid dispensing head 1 and the humidity control agent 32. The humidity control agent 32 will be described later. The packaging in this embodiment also includes a head case 30 for housing the liquid dispensing head 1. The head case 30 serves to hold and secure the liquid dispensing head 1 and protect it from accidental drops, vibrations, and other impacts that occur during logistics. The packaging material 31 has a bag shape that can hold the head case 30 containing the liquid dispensing head 1. From the viewpoint of liquid resistance and humidity resistance, materials with gas barrier properties are often used for the packaging material 31. Examples include aluminum and multilayer film.

[0028] In this embodiment, a head case 30 containing a liquid dispensing head 1 and a humidity control agent 32 are packaged together in a packaging material 31, and the opening of the packaging material 31 is heat-sealed to create a tight seal. The humidity control agent 32 in this embodiment has a form in which the humidity control agent is filled inside a paper (or film) wrapper.

[0029] The humidity control agent 32 can be a material (humidity control material) that has a humidity control effect that adjusts the humidity of the space to a certain range. For example, silica gel type B, silica alumina gel, or zeolite can be used. Among these, silica gel type B is the most suitable in terms of cost and stability. For example, silica alumina gel is more expensive than silica gel type B, and tends to become unstable in shape when water droplets adhere to it, which may lead to limitations in the selection of the material (paper or film) of the packaging bag containing the humidity control material and the placement of the humidity control agent within the packaging. Zeolite is not spherical in shape, and its shape is not uniform, so there is a risk of tearing the packaging paper. During the logistics process, the packaging may be subjected to impacts such as dropping or vibration. This may cause the material to powderize, leak out of the packaging paper bag, and adhere to the discharge port 13, which may lead to limitations in the selection of packaging paper and the placement of the humidity control agent 32.

[0030] It is desirable that the humidity control agent 32 adjusts the humidity inside the packaging material 31 to a relative humidity of 60% or less. This is because, generally, metal corrosion progresses rapidly if the relative humidity is greater than 60%. More preferably, it is desirable that the humidity control agent 32 adjusts the humidity inside the packaging material 31 to a relative humidity of 5% to 60%. This is to suppress excessive drying of the liquid dispensing head 1.

[0031] To achieve the preferred humidity range described above, it is preferable that the desiccant 32 has both a material with a humidity control effect and a material with a drying effect. Examples of desiccants include silica gel type A, calcium chloride, and quicklime. Among these, silica gel type A is the most suitable in terms of cost and stability. For example, calcium chloride is hygroscopic, and in logistics environments subject to vibration and impact from drops, there is a concern that the liquid may scatter, which could lead to limitations in the selection of packaging paper, limitations in the installation location of the desiccant 32, and an increase in costs. Also, quicklime generates heat and expands in volume when it absorbs moisture. Therefore, since the ambient temperature in logistics environments can reach 70°C, depending on the overload deflection temperature of the resin component of the liquid discharge head 1, there is a possibility that the installation location may be limited. For example, if quicklime, which generates heat, is installed in a liquid discharge head 1 or head case 30 made of resin with an overload deflection temperature of 70°C, the surface of the resin may exceed 70°C, and deformation may occur. In particular, when using polypropylene, which generally has a load deflection temperature of 57-70°C, for the head case, quicklime is not suitable as a humidity control agent.

[0032] The most preferable humidity control agent 32, which has both a humidity-regulating effect and a drying effect, is a mixture of silica gel type B and silica gel type A. Generally, silica gel type A has a higher moisture absorption rate than silica gel type B in humidity environments of 65% or less. On the other hand, silica gel type B has a higher moisture absorption rate in humidity environments of 65% or more. That is, silica gel type A exhibits high moisture absorption performance in environments with humidity of 65% or less, and silica gel type B exhibits high moisture absorption performance in environments with humidity of 65% or more. By including silica gel type A and silica gel type B in the packaging material 31, it is possible to reliably absorb moisture in the relative humidity range of 60% or more, where metal corrosion progresses rapidly, and in the relative humidity range of 60-65%, where the moisture absorption rate of silica gel type B decreases, thereby suppressing the rise in humidity.

[0033] The appropriate humidity range for precision equipment factories is 40-50%, and head packaging and air packaging are often carried out in this environment. In environments with a relative humidity of 60% or less, silica gel type B exhibits a certain degree of moisture absorption, and since silica gel type A is present in the surroundings, silica gel type B will be in a relatively low humidity space rather than an excessively low humidity environment of 0-5%. To create silica gel type B in a low humidity space, it is necessary to place silica gel type A as close as possible, and it is desirable that silica gel type B and silica gel type A be filled in a mixed state within the same packaging bag.

[0034] To elaborate on the humidity-regulating properties of silica gel type B, if silica gel type B is moved from an environment with 40% relative humidity to a space with 20% relative humidity, it will work to maintain the relative humidity of that space between 40% and 20%. On the other hand, if silica gel type B is moved from an environment with 40% relative humidity to a space with 60% relative humidity, it will work to maintain the relative humidity of that space between 60% and 40%. Silica gel type A does not possess the above reversibility at room temperature.

[0035] In inkjet packaging, it is desirable that the relative humidity inside the packaging material 31 be 60% or less, but a near-completely dry state with a relative humidity of 5% or less is undesirable. By mixing silica gel type A and silica gel type B, an excessively low humidity environment of 0-5% is eliminated. In other words, there is no risk of excessive drying, so there is no problem in setting the weight of the humidity control agent 32 to absorb more moisture than the amount of moisture inside the liquid ejection head 1.

[0036] The maximum moisture absorption capacity of the dehumidifying agent 32 is 0.5g per gram. This is the case when silica gel is left for a long period of time to absorb moisture to its limit. To reliably eliminate metal corrosion of the liquid dispensing head 1 in a logistics environment, it is not enough for the humidity to decrease after a long period of time; it is important to prevent the relative humidity from reaching 60%. To achieve this, it is desirable to adjust the amount of the dehumidifying agent 32 so that its maximum moisture absorption capacity is 10 times or more the amount of moisture contained inside the liquid dispensing head 1. Alternatively, it is desirable to set the weight of the dehumidifying agent 32 to 5 times or more its maximum moisture absorption capacity.

[0037] Furthermore, since temperature changes in the logistics environment are difficult to predict, it is difficult to predict the humidity inside the packaging material 31. For this reason, it is important to maintain the moisture absorption rate of the dehumidifier across the entire humidity range, and it is desirable that silica gel type A and silica gel type B are mixed in a 1:1 ratio, with (weight of silica gel type B) / (weight of silica gel type A) being between 0.8 and 1.2. In other words, it is preferable that the weight ratio of silica gel type B to the weight of silica gel type A is between 0.8 and 1.2. Furthermore, if the amount of dehumidifier 32 has a weight of five times or more the maximum moisture absorption capacity as described above, variations in the weight ratio (of silica gel type A and silica gel type B) will not affect the function. When using existing silica gel type A or silica gel type B packaged in specific weights, the combination of these weights can be selected as appropriate.

[0038] The humidity control agent 32 absorbs water vapor and corrosive gases inside the packaging material 31. However, due to its high absorption performance, if the gas barrier properties of the packaging material 31 are poor, there is a risk that it may absorb water vapor and corrosive gases from outside the packaging material 31 through the packaging material 31. For this reason, it is desirable that the packaging material 31 has high gas barrier properties, and it is desirable that it be a material with aluminum vapor deposition or lamination. In the case of silica gel type B, it absorbs water vapor reversibly, but the absorption of corrosive gases is not reversible. This property makes it possible to use materials that were difficult to use due to the generation of corrosive gases for the packaging material 31 and head case 30. Examples include recycled plastics and pulp molds. Pulp molds, in particular, have the advantage of being able to absorb ink if ink leaks from the liquid discharge head 1. However, there is a possibility that exposure to water vapor in a high-humidity environment will soften it and cause it to lose its original role as a shock-absorbing packaging material 31 or head case 30. Therefore, as in this embodiment, by adding a humidity control agent 32 to the pulp mold packaging material 31, it is possible to maintain the hardness of the pulp mold.

[0039] As described above, the packaging of the present invention provides a highly reliable liquid dispensing head. Furthermore, it eliminates the need for protective members in specific areas (e.g., face covers or gold plating on contact pads) that are typically provided due to concerns about humidity effects. It also prevents corrosion of metal-containing parts. Moreover, it prevents deterioration of resin materials that have been exposed to moisture, and suppresses liquid solidification and excessive viscosity in the flow path. Additionally, when the present invention is applied to a liquid dispensing head employing a piezoelectric method, it effectively suppresses deterioration of the piezoelectric element due to moisture.

[0040] Furthermore, because the humidity inside the packaging material is kept constant by the humidity control agent, components that were difficult to use due to humidity conditions can now be used (for example, head cases made of pulp mold). In addition, it also has the effect of absorbing corrosive outgassing, making it possible to use recycled resins and other materials in components such as packaging materials and head cases.

[0041] Furthermore, the present invention can be suitably used with liquid dispensing heads filled with liquids specifically for logistics, such as clear ink.

[0042] Furthermore, the packaging of the present invention can also be used when collecting liquid dispensing heads from users. In this case, the reliability of each component of the collected liquid dispensing head can be improved, and the collected liquid dispensing head and the components contained therein can be easily reused. In addition, depending on the type of humidity control agent, the humidity control agent itself can be reused and can be easily disposed of as combustible waste.

[0043] (Other embodiments) The present invention is not limited to the embodiments described above or the examples described later, and many modifications are possible within the technical concept of the present invention. For example, different embodiments or examples may be combined or implemented in combination.

[0044] This disclosure includes the following components:

[0045] (Composition 1) A liquid dispensing head mounted on a liquid dispensing device, Humidity control agent, A packaging body for a liquid dispensing head, comprising the liquid dispensing head and a packaging material for housing the humidity control agent.

[0046] (Configuration 2) The packaging material is the packaging body according to configuration 1, which seals the inside of the packaging body.

[0047] (Composition 3) The packaging body according to configuration 1 or 2, comprising the humidity control agent, type B silica gel.

[0048] (Composition 4) The packaging body according to configuration 3, further comprising a desiccant different from silica gel type B as the humidity control agent.

[0049] (Composition 5) The packaging body according to configuration 4, wherein the desiccant is silica gel type A.

[0050] (Composition 6) The packaging body according to configuration 5, wherein the weight ratio of the silica gel type B to the weight of the silica gel type A is 0.8 or more and 1.2 or less.

[0051] (Composition 7) The packaging according to configuration 5 or 6, wherein the silica gel type B and the silica gel type A are contained within the same packaging bag.

[0052] (Composition 8) The packaging body according to any one of configurations 1 to 7, wherein the relative humidity inside the packaging material is 60% or less.

[0053] (Composition 9) The packaging body according to any one of configurations 2 to 7, wherein the relative humidity inside the sealed packaging material is 60% or less.

[0054] (Composition 10) The packaging material is a packaging body according to any one of configurations 1 to 9, having gas barrier properties.

[0055] (Composition 11) The packaging material is aluminum, and the packaging is as described in any one of configurations 1 to 9.

[0056] (Composition 12) The packaging material is a packing body according to any one of configurations 1 to 9, including a multilayer film.

[0057] (Composition 13) A packaging body according to any one of configurations 1 to 12, having a head case for housing the liquid dispensing head inside the packaging material.

[0058] (Composition 14) The head case is a packaging body according to configuration 13, which includes a pulp mold.

[0059] (Composition 15) The head case is a packaging body as described in configuration 13, including paper.

[0060] (Composition 16) The head case is a packaging body according to configuration 13, which includes recycled plastic.

[0061] (Composition 17) The packaging body according to any one of configurations 1 to 16, wherein the liquid dispensing head comprises a dispensing unit for dispensing liquid and a supply unit for supplying liquid to the dispensing unit.

[0062] (Composition 18) The packaging according to configuration 17, wherein the supply unit is configured to circulate liquid between itself and the discharge unit.

[0063] (Composition 19) The liquid dispensing head is a packaging body according to configuration 18, having a plurality of the supply units. [Examples]

[0064] Examples and comparative examples of the present invention are shown below, and the present invention will be described in more detail. However, the present invention is not limited to the following examples.

[0065] (Example 1) A liquid dispensing head as shown in Figures 2 and 3 was prepared. In this example, a liquid dispensing head 1 containing pure water inside was used. The head case 30 was made of molded polypropylene resin. The packaging material 31 is a bag structure composed of a multilayer film having a polyethylene terephthalate resin layer, an aluminum layer, a nylon resin layer, and a polypropylene resin layer. The innermost layer of the packaging material 31 is the polypropylene resin layer. Using this polypropylene resin layer as a heat-sealing layer, the head case 30 containing the humidity control agent 32 and the liquid dispensing head 1 was sealed and packaged. The sealed package 100 was stored for two months in a 60°C environment as a storage test simulating logistics conditions. After that, it was stored at room temperature for one day, and then the packaging material 31 was opened to check the condition of the liquid dispensing head 1.

[0066] The above verification was performed under various conditions, changing the amount of moisture contained in the liquid dispensing head 1, the conditions of the humidity control agent 32, and the type of packaging material before long-term storage. The results are shown in Table 1.

[0067] [Table 1]

[0068] Under condition 1-1, which used a liquid dispensing head containing 1.5g of pure water and a humidity control agent 32 made by mixing 30g of silica gel type B, which has a humidity control effect, with 30g of silica gel type A, which is a desiccant, no corrosion was observed on metal parts, and there were no problems in areas where liquid was presumed to have been present, such as the dispensing port 13. On the other hand, under condition 1-5, which did not include the humidity control agent 32, corrosion was found on the pad portion 211 of the electrical wiring board 210.

[0069] Figure 6 shows the change in humidity inside the packaging material 31 of the package under condition 1-1 in response to changes in the external temperature. The solid line represents the external temperature, and the dashed line represents the humidity inside the packaging material 31. In Figure 7, the left vertical axis represents the temperature (°C) corresponding to the solid line, and the right vertical axis represents the relative humidity (%) corresponding to the dashed line. The horizontal axis represents time t, with the time when the packaging material 31 was welded (time of airtight packaging) set to 0. Since the thickness of the packaging material 31 used in Example 1 is 95 μm, the external temperature shown by the solid line is considered to be equivalent to the temperature inside the packaging material 31.

[0070] As can be seen from Figure 6, in the packaging process of the liquid dispensing head 1, the air in that environment is sealed, so it can be seen that high-humidity air (70 RH%) is sealed inside. In other words, a lot of water vapor is present inside the packaging material 31. As the humidity decreases over time, it can be seen that the water vapor sealed inside the packaging material 31 is removed by the humidity control agent 32. In the subsequent environment of 60°C, the water contained inside the liquid dispensing head 1 rapidly vaporizes (t=40~41), but the water vapor is immediately absorbed by the humidity control agent 32 (t=41~43), and it can be confirmed that the humidity inside the packaging material 31 is kept low (t=44~70). After that, even when the temperature is lowered, no increase in relative humidity is observed because there is little water vapor inside the packaging material 31 (t=70~). In summary, it was found that the humidity inside the packaging material 31 was maintained at approximately 20% by the humidity control agent 32.

[0071] Figure 7 shows the change in humidity inside the packaging material 31 of the package under conditions 1-5 in response to changes in the external temperature, and corresponds to Figure 6. That is, it shows the change in humidity inside the packaging material 31 in response to changes in the external temperature when the humidity control agent 32 is not included. The solid line represents the temperature of the external environment, and the dashed line represents the humidity inside the packaging material 31. As with condition 1-1, the thickness of the packaging material 31 used in Example 1 is 95 μm, so the temperature of the external environment shown by the solid line is considered to be equivalent to the temperature inside the packaging material 31.

[0072] As can be seen from Figure 7, in the packaging process of the liquid dispensing head 1, the air in that environment is sealed, resulting in the sealing of high-humidity air (60 RH%). Since the humidity increases over time, it is thought that the water inside the liquid dispensing head 1 evaporated over time, increasing the amount of water vapor inside the packaging material 31. Subsequently, under the environment of 60°C, it can be confirmed that the water contained inside the liquid dispensing head 1 rapidly vaporized, and the humidity increased further (t=62~86). After that, when the temperature was lowered, a state close to condensation occurred because there was already a large amount of water vapor inside the packaging material 31, and a high relative humidity was maintained (from t=86 onward).

[0073] It is known that the corrosion rate of various metals such as nickel, copper, cobalt, and iron that may be contained in a liquid dispensing head increases sharply when the relative humidity exceeds 60%. The pad portion 211 of the liquid dispensing head 1 used in Example 1 contains a copper layer and a nickel layer. Comparing this with the results shown in Figures 7 to 10, it is thought that corrosion did not occur because the relative humidity was kept below 60% by including the humidity control agent 32 in the packaging material 31.

[0074] (Example 2) A liquid dispensing head sealed in packaging material, the same as in Example 1, was prepared. That is, the liquid dispensing heads shown in Figures 2 and 3 were prepared. A liquid dispensing head 1 containing pure water inside was used. The head case 30 was made of polypropylene (PP) resin or pulp molded product. The packaging material 31 is a bag structure composed of a polyethylene terephthalate resin layer, an aluminum layer, a nylon resin layer, and a polypropylene resin layer. The innermost layer of the packaging material 31 is the polypropylene resin layer. Using this polypropylene resin layer as a heat-sealing layer, the head case 30 containing the humidity control agent 32 and the liquid dispensing head 1 inside the packaging material 31 was sealed and packaged. The sealed package 100 was left in a 60°C environment for two weeks, and then left at room temperature for two days. These conditions simulate the logistics of liquid dispensing heads.

[0075] Subsequently, the packaging material 31 was opened, and the liquid ejection head was mounted on the inkjet device shown in Figure 1, which serves as the liquid ejection device 50, and printing was performed. Next, the liquid ejection head 1 was removed from the inkjet device and placed in the head case 30. When the liquid ejection head 1 was removed from the inkjet device, it contained approximately 15g of ink inside.

[0076] The opened portion of the packaging material 31 was folded over and secured with cellophane tape to prevent the fold from coming undone. In other words, the inside of the packaging material 31 is in a semi-open state, neither completely sealed nor completely open, and the air inside the packaging material 31 is slowly affected by the external environment. In this state, the liquid discharge head was stored for 4 days under conditions of 60°C and 90RH, simulating the recovery logistics process.

[0077] The above verification was performed under various conditions, changing the amount of moisture contained in the liquid dispensing head 1, the conditions of the humidity control agent 32, and the type of packaging material 31 before long-term storage. The results are shown in Table 2.

[0078] [Table 2]

[0079] Under condition 2-1, which used a liquid ejection head containing 15g of ink internally and a humidity control agent 32 consisting of 30g of silica gel type B, which has a humidity control effect, and 30g of silica gel type A, which is a desiccant, no corrosion was observed on metal parts, and there were no problems in areas where ink was presumed to have been present, such as the ejection port 13. On the other hand, under condition 2-5, which did not include the humidity control agent 32, corrosion was found on the pad portion 211 of the electrical wiring board 210.

[0080] Next, under conditions simulating a different recovery logistics process, a package 100 containing a liquid dispensing head 1 in a head case 30 and a humidity control agent 32, placed in packaging material 31 in a semi-open state, was stored for 4 days at 60°C and 10RH%. For example, in the configuration with the humidity control agent 32 as in condition 2-1, there was no corrosion of metal parts, and there were no problems in the areas where ink was present. Although ink was present in the resin component forming the dispensing port 13 (nozzle), it could be easily removed by subsequent cleaning, and the recovered liquid dispensing head and dispensing unit 300 could be reused.

[0081] However, in the liquid dispensing head, which was stored for 4 days at 60°C and 90RH without the addition of the humidity control agent 32, thickening or partial solidification of the ink was observed, mainly around the dispensing port 13 (nozzle). Even after subsequent cleaning, this solidified ink could not be easily removed. Furthermore, even after cleaning, precipitates remained around the dispensing port 13, and the dispensing unit 300 could not be reused.

[0082] In Example 1, under sealed conditions such as the logistics environment during shipment, the amount of humidity control material and desiccant was sufficient for the amount of moisture inside the liquid discharge head, so the humidity control agent 32 maintained a low humidity. Therefore, it retained its hygroscopic capacity even after experiencing the logistics environment (Figure 6, t=70~). Furthermore, the silica gel type B, which is the humidity control material of the humidity control agent 32, has the property of trying to maintain a state close to the humidity state of the environment in which it is placed, and thus remembers a low humidity after experiencing the logistics environment. However, since it was in an environment with water vapor at the time of sealing (t=0), excessively dry humidity of 5% or less relative humidity is not remembered by the silica gel type B.

[0083] In contrast, in the semi-open configuration of Example 2, a large amount of ink (moisture) is present in the liquid discharge head 1, causing the humidity inside the packaging material 31 to rise. If the surrounding environment is humid, the humidity will rise to that level. If a humidity control agent 32 is included in the packaging material 31, the humidity control agent 32 retains a low humidity level and will attempt to lower the humidity by absorbing water vapor inside the packaging material 31. Because the inside of the packaging material 31 is semi-open, it absorbs water vapor from the surrounding environment, not water vapor generated from the liquid discharge head 1, but it can maintain its humidity control properties for a certain period of time, such as the logistics time during retrieval.

[0084] In the semi-open configuration of Example 2, if the ambient environment is low humidity, the internal humidity of the packaging material 31 will try to decrease to the same level as the ambient environment. During logistics for retrieval, the inside of the packaging material 31 is affected by the external environment and replaces the environment it was in when it was packaged. However, because the humidity control agent 32 is inside the packaging material 31, the humidity control effect of the humidity control agent 32 can suppress the inside of the packaging material 31 from becoming excessively low humidity. Since there is liquid such as ink in the discharge port 13 (nozzle) and it is in direct contact with the outside air, it easily thickens when it dries rapidly. For this reason, even in a semi-open configuration like in Example 2, the humidity control agent 32 has a significant effect in slowing down the drying rate inside the packaging material 31.

[0085] In conditions 2-13 to 2-17, pulp mold was used for the head case. In condition 2-17, where no humidity control agent was included, and in condition 2-16, where the total weight of the humidity control agent 32 was insufficient relative to the amount of ink inside the head, softening of the pulp mold was observed. Therefore, in conditions 2-15 and 2-17, an impact absorption test was conducted in which the packaging material 31 containing the liquid ejection head 1 was dropped from heights of 45, 75, and 90 cm, and the deformation of the outer shape of the liquid ejection head 1 was evaluated as the criterion. The results are shown in Table 3.

[0086] [Table 3]

[0087] Under condition 2-17, where the humidity control agent 32 was not included, deformation of the head was observed at all heights. On the other hand, under condition 2-16, where the humidity control agent 32 was included, deformation of the liquid dispensing head 1 was observed in the drop test from a height of 90 cm, but no deformation was observed at heights of 75 cm and 45 cm. From this, it was found that the strength of the pulp molded head case 30 was maintained even under condition 2-16, where the amount of humidity control agent 32 was small. In this embodiment, the evaluation was performed using a pulp molded head case, but it is thought that the strength-maintaining effect would also be observed when, for example, cardboard or resin cushioning material is placed inside the packaging material. [Explanation of Symbols]

[0088] 1. Liquid dispensing head 2 Circulation Units 13 Outlet 15 Discharge element 21 Pressure Chamber 30 head cases 31 Packaging materials 32. Humidity control agent 50 Liquid dispensing device 100 packages 210 Electrical wiring board 300 Discharge Unit 310 Discharge element substrate 320 Support Member 330 Flexible Wiring Boards

Claims

1. A liquid dispensing head mounted on a liquid dispensing device, Humidity control agent, A packaging body for a liquid dispensing head, comprising the liquid dispensing head and a packaging material for housing the humidity control agent.

2. The packaging material seals the inside of the packaging body according to claim 1.

3. The packaging body according to claim 1, wherein the humidity control agent includes silica gel type B.

4. The packaging body according to claim 3, wherein the humidity control agent further comprises a desiccant different from silica gel type B.

5. The packaging body according to claim 4, wherein the desiccant is silica gel type A.

6. The packaging body according to claim 5, wherein the weight ratio of the silica gel type B to the weight of the silica gel type A is 0.8 or more and 1.2 or less.

7. The packaging according to claim 5, wherein the silica gel type B and the silica gel type A are contained within the same packaging bag.

8. The packaging body according to claim 1, wherein the relative humidity inside the packaging material is 60% or less.

9. The packaging according to claim 2, wherein the relative humidity inside the sealed packaging material is 60% or less.

10. The packaging material has gas barrier properties, as described in claim 1.

11. The packaging material comprises aluminum, as described in claim 1.

12. The packaging material comprises a multilayer film, as described in claim 1.

13. The packaging body according to claim 1, further comprising a head case for housing the liquid dispensing head inside the packaging material.

14. The packaging body according to claim 13, wherein the head case includes pulp mold.

15. The packaging according to claim 13, wherein the head case includes paper.

16. The packaging according to claim 13, wherein the head case includes recycled plastic.

17. The packaging body according to claim 1, wherein the liquid dispensing head comprises a dispensing unit for dispensing liquid and a supply unit for supplying liquid to the dispensing unit.

18. The packaging according to claim 17, wherein the supply unit is configured to circulate liquid with the discharge unit.

19. The packaging body according to claim 18, wherein the liquid dispensing head has a plurality of the supply units.

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