JP2003080724A - Ink supply tube for ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink supply tube for an ink jet recorder which is provided with flexibility flexing resistance and durability and is superior in gas barrier properties and steam barrier properties. SOLUTION: The tube 5 is constituted into a two-layer structure. Its inner layer 50 is constituted of a tetrafluoroethylene resin, and therefore the evaporation of the moisture of ink to the outside and the invasion of the outside air into the ink can be prevented by the low steam permeability and the low gas permeability of the tetrafluoroethylene resin. Since an outer layer 51 is constituted of a silicon rubber, flexibility and flexing durability required for the tube 5 of an ink jet printer can be secured by the flexibility, and the flexing durability of the silicon rubber and also a bend of the inner layer 50 can be absorbed by the flexibility of the silicon rubber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink supply tube for an ink jet recording apparatus, and more particularly to an ink supply tube for an ink jet recording apparatus which has flexibility and bending durability and is excellent in gas barrier property and vapor barrier property. It is a thing.

[0002]

2. Description of the Related Art Conventionally, a tube supply type ink jet recording apparatus is known in which ink is supplied from an ink tank to a recording head through a tube. In this tube supply type ink jet recording apparatus, one end of the tube is connected to an ink tank provided outside the carriage, and the other end is connected to a recording head mounted on the carriage. In this way, the recording head and the ink tank are connected via the tube, and the ink in the ink tank is supplied to the recording head via the tube. Here, the ink tank connected to one end of the tube is fixed,
On the other hand, the recording head connected to the other end reciprocates in the main scanning direction together with the carriage. Further, the tube is arranged in a limited space of the main body frame. Therefore, the tube is required to have flexibility and bending durability, and in order to satisfy the performance, the tube is made of olefin rubber such as ethylene rubber or butadiene rubber.

[0003]

However, in the tube made of the above-mentioned olefinic rubber, the gas or air from the outside penetrates through the tube wall to generate bubbles in the ink. The bubbles are aggregated and grown in the ink, and there is a problem that the ink flow path is blocked to cause ink ejection abnormality and react with oxygen to cause deterioration in print quality due to a change in ink composition. . Also,
There is a problem in that the water content in the ink evaporates through the tube wall, causing ejection abnormality due to an increase in the viscosity of the ink and deterioration of the print quality due to a change in the ink composition. On the other hand, in order to solve the above problems, when the tube is made of a material having low gas permeability and vapor permeability, such as polyethylene resin or polypropylene resin, such material is generally hard and required for the tube. However, there is a problem in that the flexibility and resistance to bending cannot be satisfied.

The present invention has been made to solve the above-mentioned problems, and provides an ink supply tube for an ink jet recording apparatus which has flexibility and bending durability and is excellent in gas barrier property and vapor barrier property. The purpose is to do.

[0005]

In order to achieve this object, an ink supply tube for an ink jet recording apparatus according to claim 1 supplies ink from an ink supply source to a recording head which ejects ink onto a recording medium. The inner layer is made of a material having low vapor permeability and low gas permeability, is in contact with the ink, and is coated on the outer periphery of the inner layer, and is made of a flexible material having a larger radial thickness than the inner layer. The outer layer.

According to the ink supply tube for an inkjet recording apparatus of the first aspect, the ink of the ink supply source in the inkjet recording apparatus is supplied to the recording head for ejecting the ink onto the recording medium. Here, the inner layer in contact with the supplied ink is made of a material having low vapor permeability and gas permeability. The outer layer covering the outer periphery of the inner layer is made of a flexible material having a larger radial thickness than the inner layer.

An ink supply tube for an ink jet recording apparatus according to a second aspect is the ink supply tube for an ink jet recording apparatus according to the first aspect, wherein the inner layer is made of an olefin resin or a fluorine resin and the outer layer is made of an olefin resin. It is made of rubber, silicon rubber, or fluorine rubber.

An ink supply tube for an ink jet recording apparatus according to a third aspect is the ink supply tube for an ink jet recording apparatus according to the first or second aspect, wherein the inner layer is made of tetrafluoroethylene resin and the outer layer is silicon. It is made of rubber.

The ink supply tube for an ink jet recording apparatus according to a fourth aspect is the ink supply tube for an ink jet recording apparatus according to any one of the first to third aspects, wherein the inner diameter is about 0.8 mm to about 2.0 mm. The outer diameter is in the range of about 2.4 mm to about 4.0 mm, the thickness of the inner layer is in the range of about 60 μm to about 80 μm, and the hardness of the outer layer is Shore hardness A. It is configured in a range of approximately 60 degrees to a Shore hardness A of approximately 85 degrees.

The ink supply tube for an ink jet recording apparatus according to a fifth aspect is the ink supply tube for an ink jet recording apparatus according to any one of the first to fourth aspects, wherein the inner diameter is approximately 1.4 mm and the outer diameter is Approximately 3.0
The inner layer has a wall thickness of about 75 μm, and the outer layer has a Shore hardness A of about 70 degrees.

An ink supply tube for an ink jet recording apparatus according to a sixth aspect is the ink supply tube for an ink jet recording apparatus according to any one of the first to fifth aspects, wherein the outer layer is made of a material forming the inner layer,
The inner layer is composed of the material forming the outer layer.

The ink supply tube for an ink jet recording apparatus according to a seventh aspect is the ink supply tube for an ink jet recording apparatus according to the sixth aspect, which has a maximum diameter larger than the inner diameter of the inner layer and is reduced in diameter toward the tip. The inner layer is deformed and fitted into a connector including a tapered head portion and a neck portion that is continuous with the maximum diameter portion and has a diameter smaller than the maximum diameter portion.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a plan view showing the internal configuration of an inkjet recording apparatus 1 which is an embodiment of the present invention. This inkjet recording device 1
Is a main body frame 2, a recording head unit 3 that is included in the main body frame 2 and ejects ink onto the recording paper PP, an ink tank 4 that stores ink to be supplied to the recording head unit 3, and the ink tank 4 thereof. A tube 5 for supplying ink to the recording head unit 3 from
The recovery device 6 and a transport device for transporting the recording paper PP are provided. The tube 5 will be described in detail with reference to FIGS. 3 and 4.

The main body frame 2 is made of flame-retardant plastic in a substantially box-shaped body. A rod-shaped guide rod 7 is horizontally provided in the longitudinal direction of the main body frame 2 so that the recording head unit 3 can reciprocate in a direction A (a left-right direction in FIG. 1) orthogonal to a conveyance direction B of the recording paper PP. I support you.

The recording head unit 3 includes a carriage 3a.
And a casing 3b connected to the carriage 3a, the casing 3b is formed into a substantially box shape, and a recording head (not shown), an air trap unit 11 and the like (see FIG. 2) are housed inside the casing. There is. The internal structure of the recording head unit 3 will be described with reference to FIG.

The carriage 3a is fitted on the guide rod 7 so as to be capable of reciprocating. A belt is attached to the carriage 3a, and the belt is wound around a roller attached to a carriage motor. When the carriage motor rotates, the belt wound around the roller is driven to move the recording head unit 3.

Below the recording head unit 3, a conveying roller is arranged as a conveying device for conveying the recording paper PP. The transport roller is the recording head unit 3
The recording paper PP is conveyed in a substantially horizontal direction (arrow B) by the rotation of the conveyance motor, which is located below and in front of and below.

The recording head in the recording head unit 3 is
A plurality of, for example, four sets are provided side by side for full-color recording, and ink ejection ports are opened downward on the side facing the recording paper PP. Each set of recording heads distributes ink supplied from an air trap, which will be described later, into ink chambers for each ink ejection port, and ejects the ink from the ink ejection port by an actuator such as a piezoelectric element, similar to a known one. . Each set of recording heads is supported on the lower surface of the housing 3b of the recording head unit 3.

The ink tank 4 is the recording head unit 3
It is for storing the ink to be supplied to the recording sheet PP and is arranged below the conveyance path of the recording sheet PP. The ink tank 4 is composed of four ink tanks 4a to 4d in which black, yellow, cyan, and magenta inks corresponding to the respective recording heads are sealed. Each ink tank 4a-4d is connected to each recording head via four tubes 5a-5d.

The recovery device 6 is a device for executing recovery processing, and is arranged on the left side portion of the main body frame 2. The recovery process is a process for recovering the ink ejection state from the recording head. The recovery device 6 includes a suction cap 6a, a suction pump (not shown) that sucks ink or the like from the recording head unit 3 through the suction cap 6a, and a wiper 6b that wipes the ink ejection port forming surface of the recording head unit 3. It is configured.

The suction cap 6a is formed in a substantially box shape, and abuts on the ink ejection port forming surface of the recording head to seal the ink ejection port forming surface. A discharge tube 6c communicates with the bottom of the suction cap 6a. The ink sucked by the action of the suction pump is discharged from the suction cap 6a through the discharge tube 6c. When the suction process is completed, the suction cap 6a separates from the ink ejection port forming surface. The ink ejection port forming surface, which is contaminated by the discharged ink, is wiped by the wiper 6b made of plate-shaped rubber, and the recovery process ends.

Next, the internal structure of the recording head unit 3 will be described with reference to FIG. FIG. 2 is a plan view showing the internal structure of the recording head unit 3. Inside the recording head unit 3, an air trap unit 11 and a joint 12 are provided.

The air trap unit 11 includes a tube 5
It is for storing the bubbles generated inside. The air trap unit 11 is formed in a substantially rectangular parallelepiped shape, and is arranged at the center of the inside of the housing 3b of the recording head unit 3.
In the air trap unit 11, four independent air bubble storage portions corresponding to the respective recording heads, that is, the air traps 3 are provided.
It is configured by being divided into 0 to 33. Further, on the rear side surface of each of the air traps 30 to 33 (upper side in FIG. 2), four connecting tools 34 for connecting with the joint member 12 are arranged in a substantially linear shape. The connector 34 is formed in a taper shape whose diameter decreases toward the joint member 12, and an ink flow path, that is, an ink inlet 11f for each air trap is formed inside.

The joint member 12 includes tubes 5a-
It is for connecting 5d and each air trap 30-33. The joint member 12 is formed in a substantially rectangular parallelepiped shape and is arranged behind the air trap unit 11 (upper side in FIG. 2). The joint member 12 has four independent ink channels 12a to 12d, and a first connector 35 for coupling to the connectors 34 of the air traps 30 to 33 is provided at both ends of each ink channel. A second connecting member 36 for connecting to the tubes 5a to 5d is provided in a protruding manner.

The first connecting member 35 includes the air traps 30-.
They are arranged in a substantially straight line on the surface of the 33 facing the connecting tool 34. The first connector 35 is composed of a neck portion protruding from the main body of the joint member 12 and a head portion that extends from the neck portion and has a tapered shape that reduces in diameter toward the connector 34. . And each 1st connection tool 35 and each corresponding connection tool 34 are the connection members 37 comprised by the substantially hollow cylindrical shape.
Are inserted and connected from both ends.

Two second connecting members 36 are provided so as to project from the left and right side surfaces of the joint member 12. Second connection tool 36
Is composed of a neck portion projecting from the main body of the joint member 12 and a tapered head portion that expands from the neck portion and reduces in diameter toward the tubes 5a to 5d. And each 2nd connection tool 36 is enclosed and connected inside one end of each tube 5a-5d.

Next, the structure of the tube 5 used in the ink jet recording apparatus 1 will be described with reference to FIGS. 3 and 4. FIG. 3 (a) shows an enlarged sectional view of the tube 5. The tube 5 has a two-layer structure including an inner layer 50 that is in contact with the ink and an outer layer 51 that covers the outer periphery of the inner layer 50. The inner diameter D1 of the tube 5 is preferably set to about 1.4 mm and the outer diameter is set to about 3.0 mm. However, in the present inkjet recording apparatus 1, the inner diameter is in the range of about 0.8 mm to about 2.0 mm. The outer diameter can be configured in the range of approximately 2.4 mm to approximately 4.0 mmb. The thickness D3 of the inner layer 50 is about 60 μm to about 8
It is preferable in view of kink resistance that the outer layer 51 has a wall thickness of approximately twice or more that of the inner layer 50 in a range of 0 μm, preferably approximately 75 μm.

The inner layer 50 is made of a resin having a low vapor permeability and a low gas permeability, that is, an olefin resin or a fluorine resin such as tetrafluoroethylene (hereinafter referred to as "FEP"), polytetrafluoroethylene (hereinafter referred to as "FEP"). "PTFE"
), Polyethylene (hereinafter referred to as “PE”), and polypropylene can be used, and preferably composed of FEP.

The outer layer 51 is made of highly flexible olefin rubber, silicon rubber or fluorine rubber, for example, silicon rubber or fluorine rubber (hereinafter referred to as "FKM"), and preferably silicon rubber. . The hardness is in the range of Shore hardness A of about 60 to 80 degrees, preferably about 70 degrees.

FIG. 3 (b) shows a comparative test result table of the above-mentioned two-layer tube 5 and a single-layer tube made of a material such as polyethylene. The two-layer tube and the single-layer tube were tested with the same values of the inner diameter D1 and the outer diameter D2. In the ink dryness, that is, vapor permeability and gas permeability tests, the ink was filled in each tube made of each material, and the weight change of the ink in each tube after about 3 months was measured. . In the table,
Those with very little change are ◎, those with little change are ○,
Things that have changed a little are expressed as △. In addition, in the bending durability test and the flexibility test, each tube was repeatedly bent to confirm the occurrence of breakage or tearing of each tube.
In the table, those that did not break or tear were ○,
The result is expressed as x.

In the ink drying test, FEP, PTF
A single layer tube composed of E and PE gave good test results. On the other hand, they did not give good test results in the flexibility and bending durability tests. Also, FK
The single layer tube composed of M and silicone rubber did not give good test results in the ink drying test.
Good test results were obtained in the flexibility and bending durability tests. That is, by having a two-layer tube structure of a layer composed of FEP, PTFE, and PE and a layer composed of FKM and silicon rubber, ink drying property, flexibility,
It is considered that good results can be obtained in any of the bending durability. As described above, the inner layer 50 is FEP,
A tube having an outer layer made of silicone rubber, and an inner layer 50
When these tubes were tested on a tube composed of PE and outer layer 51 made of olefin rubber, good results could be obtained in any case. Further, no tear was generated by press fitting the connector 36 of the above-described embodiment into the tapered portion, and the sealing property with respect to the tapered portion was good.

This is because the FEP or the like constituting the inner layer 50 suppresses the evaporation of water in the ink and the invasion of air, and the flexibility of the silicone rubber or the like of the outer layer 51 causes the flexibility and bending required in the ink jet printer 1. It satisfies durability. Further, the wall thickness D3 of the inner layer 50 is approximately 75
The inner layer 50 is set to a thickness of about 70 degrees to suppress the decrease in flexibility of the tube 5 due to the excessively large wall thickness D3 of the inner layer 50, and the hardness of the outer layer 51 is set to a shore hardness A of about 70 degrees. This is because it absorbs the folds. Also,
The inner layer 50 and the outer layer 51 can be reliably bonded to each other by performing a surface treatment such as tetra-etching on the surface of FEP and silicon rubber. When the inner layer 50 is made of an olefin resin and the outer layer 51 is made of an olefin rubber, they can be co-extruded and firmly bonded to each other by fusion bonding because they are made of the same material.

Next, a second example of the tube 5 is shown in FIG.
Will be described with reference to. FIG. 4A shows an enlarged sectional view of the tube 5 of the second example. The tube 5 of the second example has a two-layer structure including an inner layer 52 that is in contact with ink and an outer layer 53 that is adhered to the outer periphery of the inner layer 52.
The tube 5 has an inner diameter D1 of about 1.4 mm and an outer diameter D3 of about 3.0 mm. Also, the inner layer 52
Is silicone rubber, and its hardness is set to a Shore hardness A of about 70 degrees. The outer layer 53 is FEP and has a thickness D3 of approximately 75 μm. That is, the tube 5 of the second example is constructed by reversing the inner layer 50 and the outer layer 51 of the tube 5 described in FIG. 3, and the same material as the above can be used.

FIG. 4 (b) is a sectional view showing a connection state between the tube 5 and the second connecting member 36 of the joint member 12 described in FIG. Similar to the above, the second
The connector 36 is inserted into the tube 5 and connected. At this time, since the inner layer 52 of the tube 5 is made of flexible silicone rubber, the flexibility of the silicone rubber causes the inner peripheral surface of the tube 5 to be in close contact with the outer peripheral surface of the second connector 36 to connect them. be able to. Therefore, the second connector 3
The outer peripheral surface of 6 can be reliably sealed, and air can be effectively suppressed from entering between the tube 5 and the second connector 36.

As described above, in the ink jet recording apparatus 1 of each embodiment, the tube 5 has a two-layer structure, and one of the layers is made of tetrafluoroethylene. Due to the low vapor permeability and low gas permeability of ethylene oxide, it is possible to prevent the evaporation of the moisture of the ink into the outside air and the invasion of the outside air into the ink. Since the other layer is made of silicone rubber, the flexibility and bending durability of the silicone rubber can ensure the flexibility and bending durability required for the tube of the inkjet recording apparatus 1, and the tube The bend can be absorbed by the flexibility of the silicone rubber.

[0036]

According to the ink supply tube for an ink jet recording apparatus of the first aspect, since the inner layer is made of a material having low vapor permeability and gas permeability, the moisture of the ink evaporates and the inside of the tube is prevented. The invasion of air can be suppressed. Therefore, it is possible to prevent thickening of the ink and non-ejection of the ink due to evaporation of water in the ink and invasion of air, and it is possible to maintain good print quality. Further, since the outer layer made of a flexible material having a larger radial thickness than the inner layer covers the outer circumference of the inner layer, it is generally made of a material having low vapor permeability and low gas permeability. It has an effect of playing a muscular role of the inner layer and satisfying the flexibility and bending endurance required for the tube.

According to the ink supply tube for an ink jet recording apparatus of the second aspect, in addition to the effect of the ink supply tube for the ink jet recording apparatus of the first aspect, the inner layer is made of an olefin resin or a fluorine resin. Since the outer layer is made of olefin rubber, silicon rubber, or fluorine rubber, it is generally easy to handle, and the manufacturing process of the ink supply tube can be facilitated.

According to the ink supply tube for an ink jet recording apparatus of the third aspect, in addition to the effect of the ink supply tube for the ink jet recording apparatus of the first or second aspect, the inner layer is made of tetrafluoroethylene resin. ,
Since the outer layer is made of silicone rubber, it has excellent flexibility and bending durability, and is extremely excellent in permeation of steam and air.

According to the ink supply tube for an ink jet recording apparatus of the fourth or fifth aspect, in addition to the effect of the ink supply tube for an ink jet recording apparatus according to any one of the first to third aspects, the inner diameter is Almost 0.
It is in the range of 8 mm to about 2.0 mm and has an outer diameter of about 2.
When the thickness is in the range of 4 mm to approximately 4.0 mm, the thickness of the inner layer is in the range of approximately 60 μm to approximately 80 μm, and the hardness of the outer layer is in the range of Shore hardness A of about 60 degrees to Shore hardness A of about 85 degrees. Since the thickness of the inner layer is within the range, the flexibility of the inner layer can be prevented from being lowered, and the bending of the inner layer can be absorbed by the flexibility of the outer layer.

According to the ink supply tube for an ink jet recording apparatus of the sixth aspect, in addition to the effect of the ink supply tube for an ink jet recording apparatus according to any one of the first to fifth aspects, an inner layer made of a flexible material is used. Therefore, the flexibility required for the inkjet recording device can be satisfied. In addition, the outer layer made of a material having low vapor permeability and low gas permeability can suppress evaporation of water in the ink and invasion of air into the tube. Therefore, there is an effect that it is possible to prevent thickening and non-ejection of the ink due to evaporation of water in the ink and invasion of gas, and it is possible to maintain good printing quality.

According to the ink supply tube for an ink jet recording apparatus of the seventh aspect, in addition to the effect of the ink supply tube for the ink jet recording apparatus of the sixth aspect, it has a maximum diameter larger than the inner diameter of the inner layer, To a connecting tool consisting of a tapered head having a diameter reduced toward the tip and a neck having a diameter smaller than the maximum diameter portion continuous to the maximum diameter portion side,
Since the inner layer is deformed and fitted, the flexibility of the inner layer allows the inner member to be fitted in close contact with the joint member, and it is possible to prevent air from entering through a gap formed between the inner layer and the joint. effective.

[Brief description of drawings]

FIG. 1 is a plan view showing an internal configuration of an inkjet recording apparatus that is an embodiment of the present invention.

FIG. 2 is a plan view showing an internal configuration of a recording head unit.

FIG. 3A is a sectional view of a tube. (B) is a tube performance test result table.

FIG. 4A is a sectional view of a tube of a second example.
(B) is sectional drawing which showed the connection condition of the tube of a 2nd example, and a 2nd connection tool.

[Explanation of symbols]

1 Inkjet recording device 3 Recording head unit 3a carriage 4 Ink tank (ink supply source) 5 (5a-5d) tubes 11 Air trap unit 12 Joint member (part of connecting tool) 36 Second connector (connector) 36a head 36b neck 50,52 inner layer 51,53 outer layer

Claims (7)

[Claims] 1. An ink supply tube for an inkjet recording apparatus, which supplies ink from an ink supply source to a recording head that ejects ink onto a recording medium, is made of a material having low vapor permeability and gas permeability, and An ink supply tube for an ink jet recording apparatus, comprising: an inner layer in contact with the inner layer; and an outer layer that is covered with the outer periphery of the inner layer and is made of a flexible material having a larger radial thickness than the inner layer. 2. The ink jet recording according to claim 1, wherein the inner layer is made of an olefin resin or a fluorine resin, and the outer layer is made of an olefin rubber, a silicon rubber or a fluorine rubber. Ink supply tube for machine. 3. The ink supply tube for an ink jet recording apparatus according to claim 1, wherein the inner layer is made of tetrafluoroethylene resin and the outer layer is made of silicon rubber. 4. The inner diameter is in the range of about 0.8 mm to about 2.0 mm, and the outer diameter is about 2.4 mm to about 4.0 mm.
The thickness of the inner layer is in the range of approximately 60 μm to approximately 80 μm, and the hardness of the outer layer is in the range of approximately 60 degrees Shore hardness A to approximately 85 degrees Shore hardness A. The ink supply tube for an inkjet recording device according to any one of claims 1 to 3, characterized in that: 5. The inner diameter is approximately 1.4 mm, the outer diameter is approximately 3.0 mm, the inner layer has a wall thickness of approximately 75 μm, and the outer layer has a Shore hardness A of approximately 70 degrees. The ink supply tube for an inkjet recording apparatus according to any one of claims 1 to 4, wherein 6. The ink supply for an ink jet recording apparatus according to claim 1, wherein the material forming the inner layer forms an outer layer, and the material forming the outer layer forms an inner layer. tube. 7. A tapered head having a maximum diameter larger than the inner diameter of the inner layer and having a diameter reduced toward the tip, and a neck portion having a diameter smaller than the maximum diameter portion continuous to the maximum diameter portion side. The ink supply tube for an inkjet recording device according to claim 6, wherein the inner layer is deformed and fitted into the connecting member.