JP2010005876A - Cap for inkjet head, wiper and maintenance mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cap that can be adopted to various kinds of ink and can be used for a long period of time, and a wiper. <P>SOLUTION: Each of the cap and the wiper for an inkjet head is formed of a rubber material whose contact angle to ink is 60 degrees or more. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cap and wiper for an ink jet head that covers nozzles arranged on the lower surface of the ink jet head, and a maintenance mechanism that performs maintenance such as cleaning of the nozzle.

  As shown in FIGS. 2 and 3, the ink jet printer has an X direction (front and back direction in FIG. 2) in which a medium (recording medium) 160 such as a printing sheet hits a platen 140 having a substantially inverted shape in the front-rear direction. Or moving the inkjet head 130 above the medium 160 mounted on the platen 140 in the Y direction, which is perpendicular to the X direction substantially perpendicular to the medium 160, in the left-right direction, from the nozzle 131 of the inkjet head. A paper moving type ink jet printer that ejects ink droplets at a predetermined timing is well known (for example, see Patent Document 1). The medium 160 is sandwiched between the feed roller 170 and the presser roller 171 and is rotated on the platen 140 in the X direction by rotating the feed roller 170 together with the presser roller 171. According to this ink jet printer, it is possible to print a character, a diagram, or a pattern comprising a plurality of ink dot arrays on the surface of the medium 160.

  Such a paper moving type ink jet printer is provided with a maintenance mechanism 100 at the side of the platen 140 as shown in FIG. The inkjet head 130 can be moved along a guide rail 150 or the like installed above the platen 140 at a side portion of the platen 140 provided with the maintenance mechanism 100.

The maintenance mechanism 100 performs maintenance such as cleaning of the inkjet head 130. The maintenance mechanism 100 includes a wiping means 110 for wiping the nozzles 131 arranged on the lower surface of the inkjet head 130 with a wiper 111 made of a rubber plate or the like, and a capping means 120 for covering the nozzles 131 arranged on the lower surface of the inkjet head 130 with a cap 122. Is provided.
According to the wiping means 110, dust attached to the nozzle 131 can be removed by wiping the nozzle 131 of the inkjet head with the wiper 111.

Further, according to the capping unit 120, the cap 122 is placed around the nozzles 131 arranged on the lower surface of the ink jet head 130 to prevent the ink in the nozzles 131 from being dried, and the ink is trial ejected (flushing) from the nozzles 131. Ink jets in the nozzles 131 can be prevented by causing the inkjet head 130 and the cap 122 to closely contact each other and reducing the pressure inside to suck ink.
For the inkjet head cap 122 as described above, conventionally, inexpensive and flexible ethylene propylene rubber (EPDM), butyl rubber, silicon rubber, or the like has often been used (see, for example, Patent Document 2).
The same applies to the cap 122 and the wiper 111 in the flat head type for fixing the media.
Japanese Patent Publication No. 2002-361881 Japanese Patent Publication No. 2002-301830

However, these rubber materials generally have low resistance to solvent ink and UV ink, and maintenance becomes impossible due to deformation due to swelling and shrinkage. In addition, the components used as a plasticizer and a vulcanizing agent in the rubber material are eluted into the ink, causing problems such as ejection failure due to the components.
If the contact angle is low even with a rubber material with high chemical resistance, it is effective for short-term defects to the above problem, but since deterioration such as swelling and elution progresses over time, it is necessary to use it stably for a long time. It was insufficient. Furthermore, when the contact angle is low, the rubber material tends to leak ink, so the cap 122 or the wiper 111 to which the ink has adhered is brought into contact with the inkjet head 130, resulting in unstable ink ejection. It was.
In addition, a rubber material having high chemical resistance is generally expensive, and even if the usable period is extended, there are many cases where it does not meet the cost.

The present invention has been devised in view of such a conventional situation, and an object thereof is to provide a cap that can be applied to a wide variety of ink types and can be used stably for a long period of time.
Another object of the present invention is to provide a maintenance mechanism that can be applied to a wide variety of ink types and can be used stably for a long period of time.

本発明の請求項５に記載のインクジェットヘッド用キャップは、請求項３又は４において、インクと接触する最外層部分に前記フッ素系エラストマーを用いたことを特徴とする。
本発明の請求項６に記載のインクジェットヘッド用ワイパーは、インクに対する接触角が６０度以上であるゴム材料を用いたことを特徴とする。
本発明の請求項７に記載のメンテナンス機構は、請求項１乃至請求項６のいずれかに記載のインクジェットヘッド用キャップ及び／又はワイパーを備えたことを特徴とする。 The cap for an ink jet head according to claim 1 of the present invention is characterized by using a rubber material having an ink contact angle of 60 degrees or more.
The cap for an inkjet head according to claim 2 of the present invention is the cap according to claim 1, wherein the rubber material is immersed in ink heated to 45 ° C to 60 ° C for 1 week to 1 month. Further, the weight change rate before and after that is within ± 5%.
The cap for an ink jet head according to claim 3 of the present invention is characterized in that in claim 1 or 2, the rubber material is a fluorine-based elastomer.
According to a fourth aspect of the present invention, the cap for an ink jet head according to the third aspect is characterized in that the fluorinated elastomer has a fluorinated polyether skeleton represented by the following general formula (1).

According to a fifth aspect of the present invention, the cap for an ink jet head according to the third or fourth aspect is characterized in that the fluoroelastomer is used in an outermost layer portion that comes into contact with ink.
The wiper for an ink jet head according to claim 6 of the present invention is characterized by using a rubber material having an ink contact angle of 60 degrees or more.
According to a seventh aspect of the present invention, there is provided a maintenance mechanism comprising the inkjet head cap and / or wiper according to any one of the first to sixth aspects.

  In the present invention, by using a rubber material having a contact angle with respect to the ink of 60 degrees or more, the range and time of contact with the ink can be reduced. Thereby, deformation due to expansion / contraction of the rubber material can be suppressed. Further, it is possible to prevent the components in the rubber material from eluting into the ink. Furthermore, since it is difficult for ink to remain on the cap and the wiper, maintenance can always be performed in a clean state. As a result, the present invention can provide a cap and a wiper that can be applied to a wide range of ink types and can be used stably for a long period of time.

  In the present invention, since the cap and wiper made of a rubber material having a contact angle with respect to the ink of 60 degrees or more are provided, the range and time in which the cap and the wiper are in contact with the ink are reduced. Thereby, deformation due to expansion / contraction of the rubber material can be suppressed. Further, it is possible to prevent the components in the rubber material from eluting into the ink. As a result, the present invention can provide a maintenance mechanism that can be applied to a wide range of ink types and can be used stably for a long period of time.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an ink jet head cap, a wiper, and a maintenance mechanism according to an embodiment of the invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically showing a configuration example of the maintenance mechanism of the present invention.
This maintenance mechanism is a maintenance mechanism for an inkjet head, and includes the inkjet head cap and wiper of the present invention.

The maintenance mechanism 1 is made of a rubber plate or the like, and includes a wiping means 10 having a wiper 11 for wiping nozzles 31 arranged on the lower surface of an ink jet head 30, and a capping having a cap 22 on which an ink absorbing sponge 21 is laid. Means 20.
The capping means 20 covers the periphery of the nozzles 31 arranged on the lower surface of the ink jet head 30 to prevent the ink in the nozzles 31 from being dried, and allows the ink to be ejected from the nozzles 31 by trial. The cap 31 is in close contact, the inside is decompressed, and the ink is sucked to prevent ink clogging in the nozzle 31.

In particular, the present invention is characterized in that a rubber material having a contact angle with respect to ink of 60 degrees or more is used for the cap 22.
Conventionally, in the cap 122 that is placed around the nozzle 131 of the ink jet head 130 and is in direct contact with the ink, if the rubber material constituting the cap 122 is deformed due to swelling or shrinkage, the airtightness is deteriorated, so that maintenance becomes impossible. (See FIG. 2). In addition, if the components used as plasticizers or vulcanizing agents for rubber materials elute into the ink, causing defective head ejection due to the components, and maintenance is performed with caps and wipers where ink remains, maintenance success rate Go down. In addition, there is a problem that the inkjet head is soiled or damaged by performing maintenance with a dirty wiper. In addition, the replacement period of the cap 122 wiper 111 and the like is shortened, leading to an increase in cost (see FIG. 2).

  In order to solve the above problems, in the present invention, as a material for the cap 22 and the wiper 11, in addition to high chemical resistance, a rubber material having a contact angle with respect to various inks of 60 degrees or more is used. It will have a sex. That is, the range and time in which the cap 22 and the wiper 11 are in contact with ink can be reduced. Thereby, deformation due to expansion / contraction of the rubber material can be suppressed. Further, it is possible to prevent the components in the rubber material from eluting into the ink. Further, it is difficult for ink to remain on the cap 22 and the wiper 11, and maintenance can be performed in a clean state. Thereby, the cap 22 and the wiper 11 of the present invention can be applied to a wide variety of ink types and can be used stably for a long time.

The rubber material preferably has a weight change rate within ± 5% before and after immersing the ink heated at 45 ° C. to 60 ° C. for 1 week to 1 month.
By using a rubber material whose weight change rate when it is immersed in ink for a long time is within ± 5%, deformation of the cap 22 and the wiper 11 due to expansion / contraction of the rubber material can be suppressed to a minimum. Moreover, it can prevent more effectively that the component in a rubber material elutes in an ink. Thereby, the cap 22 and the wiper 11 can be used more stably and for a long time.

前記のようなフッ素化ポリエーテル骨格を有するフッ素系エラストマーを用いることで、インクに対してより高い發液性を有するものとなり、キャップ２２がインクと接触する範囲、時間をより少なくすることができる。これにより、上述したような本発明の効果をより高いものとすることができる。 As such a rubber material, various rubber materials can be used, and a fluorine-based elastomer is particularly preferable.
Specifically, the fluorinated elastomer preferably has a fluorinated polyether skeleton represented by the following general formula (1).

By using the fluorinated elastomer having the fluorinated polyether skeleton as described above, the ink has higher liquid repellency, and the range and time in which the cap 22 contacts the ink can be reduced. . Thereby, the effect of the present invention as described above can be further enhanced.

  The cap 22 and the wiper 11 of the present invention may be entirely made of a fluorine-based elastomer as described above, or only the outermost layer portion in contact with the ink of the cap 22 and the wiper 11 is fluorine-based. An elastomer may be used. Use only rubber material with high chemical resistance and high contact angle for the outermost layer part that comes into contact with ink, and use less expensive rubber material or plastic for the inner layer part to reduce the amount of expensive rubber material used. Can reduce costs.

Next, the operation of the inkjet head maintenance mechanism 1 of the present invention will be described.
As shown in FIG. 1, in an ink jet printer, a maintenance mechanism 1 is provided at a side portion of a platen 40. The inkjet head 30 can be moved along the guide rail 50 or the like installed above the platen 40 to the side of the platen 40 provided with the maintenance mechanism 1.
The maintenance mechanism 1 can perform maintenance such as cleaning of the inkjet head 30.

Specifically, the nozzles 31 arranged on the lower surface of the inkjet head 30 are wiped by the wiper 11 of the wiping means 10. Thereby, dust adhering to the nozzles 31 arranged on the lower surface of the inkjet head 30 can be removed.
Further, the cap 22 is placed around the nozzles 31 arranged on the lower surface of the inkjet head 30 by the capping means 20. The cap 22 can prevent the ink in the nozzle 31 from drying. Further, the ink clogging in the nozzle 31 can be prevented by causing the nozzle 31 to eject the ink into the cap 22 on which the sponge 21 is laid. At this time, the cap 22 can prevent the ink ejected from the nozzle 31 from being scattered in the space around the nozzle 31. Further, by reducing the pressure between the cap 22 and the inkjet head 30 and sucking the ink, the periphery of the nozzle can be cleaned with new ink.

  Since the maintenance mechanism 1 for an ink jet head includes the cap 22 and the wiper 11 made of a rubber material having a contact angle with respect to the ink of 60 degrees or more, the range and time in which the cap 22 and the wiper 11 are in contact with the ink. Can be reduced. Thereby, deformation of the cap 22 and the wiper 11 due to expansion / contraction of the rubber material can be suppressed. Further, it is possible to prevent the components in the rubber material from eluting into the ink. Furthermore, it is difficult for ink to remain on the cap 22 and the wiper 11, and maintenance can be performed in a clean state. As a result, the maintenance mechanism 1 according to the present invention can be applied to a wide range of ink types, and the replacement period of the cap 22 and the wiper 11 becomes long, so that it can be used stably for a long time. Further, the replacement period of the cap 22 and the wiper 11 becomes longer, which leads to cost reduction.

  As described above, the cap and the maintenance mechanism for the inkjet head of the present invention have been described. However, the present invention is not limited to this, and can be appropriately changed without departing from the spirit of the invention.

Hereinafter, specific examples of the present invention will be described. The present invention is not limited to these examples.
The contact angle measurement, member immersion test, and maintenance test were performed and evaluated for various rubber materials by the following methods.
(1) Contact angle measurement EPDM (ethylene propylene rubber), Viton (fluoro rubber), and fluorine elastomer were prepared as rubber materials.
Further, UV ink 1, UV ink 2, solvent ink were prepared as inks, and cleaning liquid 1 and cleaning liquid 2 were prepared as cleaning liquids.
The UV ink 1 used was SPC-0371K-2 manufactured by Mimaki Engineering, the SPC-0516K manufactured by Mimaki Engineering was used as the UV ink 2, and the SPC-0549K manufactured by Mimaki Engineering was used as the solvent ink.
Further, SPC-0371FS manufactured by Mimaki Engineering was used as the cleaning liquid 1, and SPC-0516FS manufactured by Mimaki Engineering was used as the cleaning liquid 2.
1.5 μl of each ink / cleaning liquid was dropped on these rubber materials, and the contact angle 10 seconds after the landing was measured. The results are shown in Table 1.

(2) Member immersion test The ink and cleaning liquid were 45 ° C. Each was heated to 60 ° C. The members made of the rubber material were immersed in warm ink and cleaning liquid for 1 week, respectively, and the weight change before and after the measurement was measured. The results are shown in Table 2.

(3) Maintenance Test As an example, a cap made of fluorine elastomer SIFEL3511 (manufactured by Shin-Etsu Chemical) and a cap made of EPDM as a comparative example were prepared, and each was mounted on a flat head type UV inkjet printer (UJF-605C). Then, using SPC-0516K ink (manufactured by MIMAKI ENGINEERING), the cap was brought into close contact with the inkjet head at a rate of once a week, and filling and discharging were performed by pump suction. Then, by measuring the ink consumption, it was evaluated whether the filling and discharging were properly performed. At this time, the cap was left uncleaned for a time other than work.

As a result, with the cap of the comparative example made of EPDM, maintenance became impossible in one month, but with the cap of the example made of fluoroelastomer, there was no problem even if it was used for more than 3 months.
As described above, by using a rubber material having a contact angle of 60 degrees or more with various inks, deformation due to expansion / contraction of the rubber material, elution of the rubber material component into the ink, and weight change caused by these. It was found that can be prevented. And it was confirmed that the cap of the present invention using such a rubber material can be used stably for a long time. It has been found that a fluorine elastomer is particularly suitable as such a rubber material.

  The present invention is widely applicable to a cap and wiper for an inkjet head, and a maintenance mechanism.

It is a figure which shows typically an example of the maintenance mechanism for inkjet heads of this invention. It is a figure which shows typically an example of the conventional maintenance mechanism for inkjet heads. It is a figure which shows typically an example of the conventional maintenance mechanism for inkjet heads.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Maintenance mechanism, 10 ... Wiping means, 11 ... Wiper, 20 ... Capping means, 21 ... Sponge, 22 ... Cap, 30 ... Inkjet head, 31 ... Nozzle

Claims (7)

  A cap for an ink jet head, wherein a rubber material having a contact angle with respect to ink of 60 degrees or more is used.   The rubber material has a weight change rate of within ± 5% before and after immersing the ink heated to 45 ° C to 60 ° C for one week to one month. Item 2. The inkjet head cap according to Item 1.   The ink-jet head cap according to claim 1, wherein the rubber material is a fluorine-based elastomer. The inkjet head cap according to claim 3, wherein the fluorine-based elastomer has a fluorinated polyether skeleton represented by the following general formula (1).

  The cap for an ink jet head according to claim 3 or 4, wherein the fluoroelastomer is used in an outermost layer portion in contact with ink.   A wiper for an ink jet head, wherein a rubber material having a contact angle with ink of 60 degrees or more is used.   A maintenance mechanism comprising the inkjet head cap and / or wiper according to any one of claims 1 to 6.

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