JPH02239942A - Damper film for ink jet recorder - Google Patents

Abstract

PURPOSE:To obtain satisfactory characteristics for not deteriorating the state of ink by providing a damper film having a structure of a plurality of layers composed of a material disposed on a surface layer in contact with the ink and having ink resistance properties, a material having small moisture permeability and a material having small air permeability. CONSTITUTION:A plurality of layers (1, 2,..., n) formed of different materials are provided. Each layer has one or a plurality of ink resistance properties, small moisture permeability and small air permeability, and the layers are combined as a whole to satisfy these properties. For example, in case of three layer structure, the first layer in contact with the ink is formed of polyethylene resin having 50mum of thickness, the third layer 23 in contact with the air is formed of polyvinylidene chloride having 12mum of thickness, and the second layer 22 disposed therebetween is formed of elongated polyethylene terephthalate having 12mum of thickness. Thus, since ink pressure variation is absorbed, the ink resistance properties is desirable, the moisture permeability is low and the air permeability is small, a satisfactory damper film which does not deteriorate the quality of the ink can be obtained.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a damper film that is provided between an inkjet head and an ink tank of an inkjet recording device and forms a pressure damper that absorbs pressure fluctuations in ink without deteriorating the quality of ink. The purpose of the inkjet recording device is to have characteristics that enable stable printing, and the damper film as described above is composed of a plurality of layers made of different materials. Each layer must have one or more of the following properties: ink resistance, low moisture permeability, and low air permeability, and the overall layer must have ink resistance and low moisture permeability. and a combination that satisfies low air permeability.

(Industrial Application Field) The present invention relates to a damper film for an inkjet recording device, and more specifically, a damper film that is provided between an inkjet head and an ink tank of an inkjet recording device to absorb pressure fluctuations in ink. Regarding damper film.

[Conventional technology]

There is an inkjet recording apparatus shown in FIG. 4. In the figure, 7 is an ink tank that stores liquid ink produced by vacuum injection, 3 is an inkjet head that sprays ink onto recording paper 5 based on the control of a control device (not shown), and 6 is a supply of ink from the ink tank to the ink head. The ink supply tube is shown. This ink head 3 is attached to a head carriage 4, and is scanned in the main scanning direction under the control of a control device to perform printing.

By the way, in such an inkjet recording device, the ink tank 6 is generally fixed to the main body of the device, while the inkjet head 3 is moved by the head carriage 4, so the ink supply tube may be deformed or the ink may be damaged due to the inertia of the ink. pressure fluctuations may occur.

If such pressure fluctuations occur in the ink, the ink cannot be stably ejected from the inkjet head. Therefore, a pressure damper is provided between the ink tank and the inkjet head to absorb pressure fluctuations.

[Problem to be solved by the invention]

By the way, the conventional pressure damper described above has a structure as shown in FIG. 9. In FIG. 9, reference numeral 10 denotes a pressure damper main body made of polyethylene or the like, which has a through hole l3 formed in a plate-like member, and an ink inflow cylinder 11 and an ink delivery cylinder 12 that pass through this through hole. It is. Flexible films 14 and 15 are attached to both sides of the opening of the through hole 13 to form an ink storage section 16. Ink is stored in this ink storage part, and the films 14 and 15 of the ink storage part absorb fluctuations in ink pressure caused by the movement of the ink head, so that the fluctuations in ink pressure are not transmitted to the ink head. It is designed to be able to achieve stable printing.

By the way, from the viewpoint of adhesion to the pressure damper body, the above-mentioned film has conventionally been made of polyethylene, which can be easily thermally welded to the pressure damper wood body, but what is good about the material? There was no particular consideration given to this.

If the material of the film is moisture-permeable, the water, which is the solvent in the ink, will evaporate, increasing the viscosity of the ink and flow resistance, which can cause ink head jetting failure. It is possible to wake up. In addition, if the ink is breathable, gases in the air dissolve into the ink, and when the temperature of the ink rises and the solubility of the gas decreases, bubbles are generated in the ink, and this gas flows into the ink head. If it gets inside, it will absorb the pressure fluctuations caused by the piezoelectric element of the ink head, and there is a risk that ink will not be ejected, so care must be taken when selecting the material.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a damper film for an inkjet recording device, which has characteristics that allow stable printing without causing deterioration of the ink in the inkjet recording device.

[Means to solve the problem]

In the present invention, means for solving the above problems are as follows:
As shown in FIG. 1, a damper film is provided between an inkjet head and an ink tank of an inkjet recording device to form a pressure damper that absorbs pressure fluctuations in ink, and is made up of multiple layers made of different materials. (1,
2,...n), and each layer has one or more of the following properties: ink resistance, low moisture permeability, and low air permeability, and the ink resistance as a whole , low moisture permeability, and low air permeability.

[Effect]

According to the present invention, since the inner layer in contact with the ink has ink resistance, impurities from the film do not dissolve into the ink and cause the ink to become defective, and the inner layer is made of a material with low moisture permeability and a material with low air permeability. The layer composed of the above prevents water, which is the solvent of the ink, from evaporating, and also prevents gaseous components in the air from dissolving into the ink. Therefore,
The viscosity of the ink supplied to the ink head may increase,
Gas components dissolved in the ink will no longer appear as bubbles, clogging the inkjet head and causing printing defects.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of damper films for inkjet recording apparatuses according to the present invention will be described below with reference to the drawings.

2 to 5 show a pressure damper to which a pressure damper film of an inkjet recording apparatus according to the present invention is attached. In this embodiment, the pressure damper 3 is provided between the inkjet head and the ink tank.

As shown in FIGS. 2 to 5, this pressure damper 40 has a plate-shaped pressure damper body 41 made of injection molded polyethylene.
Grooves and holes are formed on both sides, and the film according to the present invention is adhered to both sides, so that the grooves serve as ink flow paths and the holes serve as spaces. In the figure, the thickness of the film is exaggerated and drawn thick. That is, pressure absorbing portions 42 are provided approximately in the middle of both surfaces 41a and 4lb of the pressure damper body 41.
is recessed in a circular shape, and a communication hole 43 is provided that communicates both pressure absorbing portions 42 with each other. Here, this communication hole 43
is provided to cover the entire height of the pressure absorbing portion 42. An ink inflow plug part 44 into which an ink supply tube is inserted is formed at the upper end of the pressure damper wooden body 40, and an ink ink supply tube is formed on the first surface 41a of the pressure damper so as to communicate with the hole 45 of the ink inflow plug part 44. The inflow path 46 is formed in a groove shape and communicates with the lower part of the pressure absorbing section 42 .

Further, on the other surface 4lb of the pressure damper main body 41, two communicating passages 48 and 49 are recessed to communicate with the lower part of the pressure absorbing portion 42 and sandwich the island portion 47, and a mesh filter 50 for filtering ink is provided. A mounting stepped portion 51 is formed to which the mesh filter 50 is attached. Then, on the other surface 4lb, an ink outflow path 52 is formed in a groove shape with the mesh filter 50 sandwiched therebetween, and an ink outflow hole 5 opening in the first surface 41a is formed.
3.

Further, in this embodiment, the other surface 4 of the pressure damper main body 41
lb is provided with a bubble discharge path 54 that communicates with the upper part of the pressure absorption section 42 and discharges bubbles during the purge operation,
It is connected to a dummy noise for air bubble evacuation provided in the inkjet head through an air bubble ejection tube.

Then, the films 55, 56 according to the present invention are attached to both surfaces 41a, 4lb of the pressure damper main body 41 configured in this way, so that each passage 46, 52 and the pressure absorbing part 42 have a closed cross-sectional structure, It constitutes a pressure damper.

Next, the structure of the damper film of the inkjet recording apparatus according to the present invention will be explained.

FIG. 6 shows a first embodiment of a damper film for an ink jet recording apparatus according to the present invention. In this embodiment, the damper film has a double structure as shown in FIG. That is, the first layer 17 in contact with the ink is made of polyethylene resin with a thickness of 50 lm,
The second layer 20 exposed to air is made of polyvinylidene chloride with a thickness of 18 ILm.

Next, a second embodiment of the present invention will be described. In this embodiment, the damper film has a triple structure as shown in FIG. That is, the first layer 21 in contact with the ink has a thickness of 50JJ.
The third layer 23 is made of polyethylene resin with a thickness of 12 g.m and is exposed to air. a second layer 2 formed of polyvinylidene chloride with a thickness of m between the first layer and the third layer;
2 has this three-layer structure film using stretched polyethylene terephthalate with a thickness of 12 pm.

Even after putting ink into a bag made from this film and storing it at 50 degrees Celsius for one week, there was no change in the ink, and when printing was performed using this ink, no printing defects such as missing prints occurred. . In this example, oriented polyethylene terephthalate was used as the second layer, but in experiments conducted by the applicant, similar effects were obtained by using oriented nylon or oriented polypropylene as the second layer.

Note that polyethylene and polyvinylidene chloride can be bonded together by heat fusion, or can be bonded together using a polyester adhesive. Based on these experimental results, the film conditions are as follows: 1. Low air permeability.

■ Low moisture permeability.

■　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

It can be said that this is necessary. And especially the transparency is 1
It can be said that it is desirable that the oxygen permeability is 5 g/m224 hrs or less and the oxygen permeability is 50 cc/m224 hrs or less.

Table 1 In addition, as another plastic material, Teflon (PTFE) with a thickness of 25ILm has a moisture permeability (g/m2, 24hrs
) 5. 4, and the oxygen permeability (cc/m224hr
s atm: 20°C dry) is 3500~56o
Similarly, nylon having a thickness of 30 JLm has a moisture permeability of 120 to 150 and an oxygen permeability of 21, so these can also be used in various combinations, taking into consideration the ink properties.

An experimental example is shown below. Note that the first layer will be described as a layer that comes into contact with ink.

[Experimental Example 1] As shown in FIG. 6, the first layer is a polyethylene resin with a thickness of 50 JLm, and the second layer is a polyethylene resin with a thickness of 12 p.m. m
When a bag made of polyvinylidene chloride film was filled with 10 g of ink and stored at 50°C for one week, there was no change in the filled ink. Further, when printing was performed using this ink, no printing defects such as missing prints occurred.

■ As shown in Figure 7, the first layer has a thickness of 50 JLm.
The second layer has a thickness of 12J1. m
coated with oriented polyethylene terephthalate of thickness 2
-3 pm of polyvinylidene chloride, and the polyvinylidene chloride was bonded to form the outer layer. When a bag made of this film was filled with ink and stored at 50° C. for one week as in Experimental Example (2), the same results as in Experimental Example (2) were obtained.

[Comparative Example] ■ As a comparative example, the thickness was 15 p. When an experiment was conducted under similar conditions using ethylene vinyl alcohol copolymer (EVAL), the ink amount decreased to 2 g and the viscosity increased significantly.

■ In the case of polyethylene and polypropylene with a thickness of 30 ILm, the presence of air was confirmed.

(2) In the case of polyvinylidene chloride with a thickness of 307 mm, no air generation, no change in ink weight, and no change in viscosity was observed. However, eluted substances were detected in the ink, and it was found that there was a problem with ink resistance.

Table 1 shows the moisture permeability and oxygen permeation of various plastic materials. In Table 1, the measurement conditions for moisture permeability are 40°C and 90% RH, and the measurement conditions for oxygen permeation are 35°CO%RH on the left side and 20°C and 65%RH on the right side.

Therefore, according to each of the above embodiments, in addition to absorbing ink pressure fluctuations as a damper film of an inkjet recording device, it also has good ink resistance, low moisture permeability, and low air permeability, so that the quality of ink is not deteriorated. A good damper film could be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, the damper film of an inkjet recording device is made of a material having ink resistance, a material having a low moisture permeability, and a material having a low air permeability, which are disposed on the surface layer in contact with the ink. Because the damper film has a multi-layer structure made up of It was possible to obtain a damper film with good characteristics that does not melt into the ink and do not deteriorate the condition of the ink.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention, FIG. 2 is a diagram showing an embodiment of the pressure damper of an inkjet printer according to the present invention, and FIG.
The figure shows the pressure damper shown in FIG.
4 is a sectional view taken along the line IV-IV in FIG. 2 of the pressure damper shown in FIG. 2, and FIG. 5 is a sectional view taken along the line IV-IV in FIG. V-line cross-sectional view, 6th
FIG. 7 is a sectional view showing an embodiment of the damper film of the first inkjet recording device according to the present invention, FIG. 7 is a sectional view showing an embodiment of the damper film of the second inkjet recording device according to the present invention, This figure is a diagram showing the configuration of an inkjet recording apparatus, and FIG. 9 is a sectional view showing the structure of a pressure damper. 1...Surface layer in contact with ink 2...Multiple layers

Claims (1)

[Claims] A damper film that is provided between an inkjet head and an ink tank of an inkjet recording device and forms a pressure damper that absorbs pressure fluctuations in ink, comprising a plurality of layers (1) formed of different materials. , 2,...n), and each layer has one or more of the following properties: ink resistance, low moisture permeability, and low air permeability, and the overall ink resistance 1. A damper film for an inkjet recording device, characterized by having a satisfactory combination of properties, low moisture permeability, and low air permeability.