JP2002212869A - Sheet-shaped fiber assembly and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet-shaped fiber assembly having an increased diffusion-osmotic force and an improved effective absorption power of ink by further subjecting a fiber assembly obtained by laminating and forming fibers to a pressing treatment and thereby stimulating the contact between the fibers constituting the skeleton of the fiber assembly and the ink absorbed in the voids among the fibers, and a method for manufacturing the same. SOLUTION: The diameters of fibers 12 constituting a sheet-shaped fiber assembly 10 is set in the range of 1-7 dtex, and the density of the obtained sheet-shaped fiber assembly 10 is set at least at >=0.15 g/cm3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-like fiber assembly and a method for producing the same, and more particularly, to a sheet-like fiber assembly used for an ink-jet printer and capable of suitably removing ink remaining on an ink head. The present invention relates to a fiber assembly and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, with the spread of electronic image technology using a computer, a digital camera, and the like, an ink jet printer has been suitably used as a device for easily outputting these images. The outline of this ink jet printer is described as follows: an image is regarded as a group of small points (hereinafter referred to as dots), and the dots are printed by discharging ink as minute droplets from fine nozzles to express a desired image.・ It is something to output.

[0003] The ink used in the ink jet printer is stored in a predetermined ink tank, and has a structure in which a required amount of ink is ejected from a dedicated ink head at the time of printing. There is a fear that air bubbles such as air may be mixed during use to adversely affect subsequent printing. In such a case, the air bubbles are removed by performing so-called cleaning in which a large amount of the ink is ejected from the ink head.

However, as described above, when removing air bubbles,
Since a large amount of ink is ejected, the ink head is contaminated with the ink, so that subsequent printing cannot be performed satisfactorily. In addition, since the ink has various physical properties such as quick drying property that can be dried immediately after ejection, it is necessary to remove excess ink ejected for removing bubbles in a short time as possible. There is.

For this reason, as shown in FIG. 5, a normal ink head portion is provided with a rubber blade 54 for scraping off and removing residual ink by making direct contact with the ink head 50, and a blade for the ink head 50. Absorbers 52, 52 are provided on both sides in the moving direction of the residual ink removal 54 and quickly absorb and remove the ink remaining on the surface of the blade 54 after being scraped off.

The blade 54 and the absorbers 52, 52
Explaining the function of (1), as shown in FIG. 5A, at the normal printing position, excess ink remains on the lower side, which is the ink ejection side of the ink head 50 that has performed the cleaning operation. Then, as shown in FIG. 5B, the blade 54 contacts and scrapes the residual ink stored under the ink head 50. Most of the residual ink remains on the surface of the blade 54 and is absorbed by a predetermined ink absorbing member (not shown), and a very small amount of ink adheres to the surface of the blade 54. The ink adhering to the surface of the blade 54 is absorbed by the absorber 52 by contacting one of the absorbers 52 provided on both sides of the ink head 50 as shown in FIG. The blade 5
The surface of No. 4 returns to the initial state without residual ink. As described above, since the absorber 52 is provided on both sides of the ink head 50 in the moving direction of the blade 54,
No matter which side the removal by 4 starts, the absorption by the absorber 52 is performed immediately after the ink head 50 is scraped off.

Since the ink discharge portion of the ink head 50 is determined, the portion where the residual ink is stored in the ink head 50, the portion where the residual ink adheres on the blade 54, and the portion where the residual ink is absorbed in the absorber 52. Is limited to the determined part.

The absorber 52 is made of a material having a good absorbency, such as a felt or pulp non-woven fabric, and is used in a required shape by die cutting or the like. Further, with respect to this absorber, there has been a demand for downsizing with the recent downsizing of the printer body.

[0009]

However, in the case of the above-mentioned material which has been employed, the absorbed residual ink is replaced by the absorbed residual ink as shown in FIG.
(See FIG. 6A), the ink remained only in the vicinity of the absorbed portion and did not spread to other portions (see FIG. 6B), and the residual ink was partially saturated. This phenomenon is inferred as follows. That is, the residual ink absorbed by the capillary action by the fibers constituting the absorber 52 (the force obtained thereby is hereinafter referred to as a capillary force) is absorbed by the absorber 52.
Not only on the surface, but also permeate inside. However, since each fiber that expresses the capillary force is composed of the absorber 52 in a state full of voids (low density) at predetermined intervals,
The residual ink held in the gap is separated from the fibers, so that it also exerts a capillary force and stays at the site. That is, it lacks the diffusion penetration power.

[0010] Due to such a phenomenon, even an absorbent using fibers capable of exhibiting a sufficient capillary force lacks diffusion penetration power and cannot use the whole volume efficiently (the effective absorption power is small). Therefore, it may be difficult to sufficiently remove the residual ink. In order to avoid this problem, the thickness of the absorber 52 may be made larger. However, in this case, the size of the printer cannot be sufficiently reduced. In other words, it has been pointed out that a certain size or more is required in order to achieve the required effective absorbing power of the residual ink, and when the size is limited, a sufficient effective absorbing power cannot be achieved.

[0011]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the problems associated with the prior art, and has been proposed in order to solve the problem suitably. The present invention relates to a fiber assembly obtained by laminating and molding fibers. Compression to promote the contact between the fibers constituting the skeleton portion of the fiber assembly and the ink absorbed in the voids between the fibers, thereby increasing the diffusion penetration power and increasing the effective ink efficiency. It is an object of the present invention to provide a sheet-like fiber aggregate having improved absorption power and a method for producing the sheet-like fiber aggregate.

[0012]

Means for Solving the Problems In order to overcome the above-mentioned problems and achieve the intended object, a sheet-like fiber aggregate according to the present invention is obtained by laminating fibers as raw materials to form a cotton-like laminate. A sheet-like fiber aggregate obtained by performing heat fusion and heat compression, wherein the fiber diameter of the fiber is set in a range of 1 to 7 dtex and the density of the sheet-like fiber aggregate is at least 0.15 g / cm ³ or more.

[0013] In order to overcome the above-mentioned problems and achieve the intended object, a method of manufacturing a sheet-like fiber aggregate according to another invention of the present application comprises laminating fibers as a raw material to form a cotton-like laminate. In a method of producing a sheet-like fiber aggregate by performing heat fusion and heat compression, a release paper is interposed on both sides of the fiber aggregate obtained by performing heat fusion on the cotton-like laminate, and the release paper is formed. The sheet-like fiber aggregate is manufactured by removing the release paper after heat-compressing the sheet.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a sheet-like fiber aggregate and a method for producing the same according to the present invention will be described with reference to the accompanying drawings, together with a production method, with reference to preferred embodiments.

As shown in FIG. 1, a sheet-like fiber assembly 10 according to a preferred embodiment of the present invention is obtained by processing a plurality of fibers 12 having a required diameter fused to each other to a predetermined thickness.

As shown in FIG. 2, the method for producing the sheet-like fiber aggregate 10 is to perform a cotton wool for forming the fibers 12 into a predetermined shape, and to obtain a cotton laminate (hereinafter referred to as a cotton-like laminate). Is basically composed of a cotton wool / fusing step S1 for obtaining a temporarily formed fiber assembly by heating the same, a heat compression step S2 for further compressing the obtained fiber assembly, a post-processing step S3 and a final step S4. .

In the mold cotton / fusing step S1, the fibers 12 capable of suitably producing the sheet-like fiber aggregate 10 are processed into cotton and the cotton-like laminate obtained in order to obtain a required basis weight is obtained. Are laminated by a method such as a cross layer if necessary,
Next, it is a stage of making this cotton-like laminate into a fiber aggregate having a predetermined molding density.

As the fiber 12, as shown in FIG.
Core member 1 in which crystalline polypropylene is used inside
2a, a sheath member 12b in which polyethylene having a melting point lower than that of the crystalline polypropylene is used is disposed on the outside thereof, and a composite fiber exhibiting heat-fusibility is suitably used.
(See FIG. 3A). The feature of the fiber 12 is that the outer sheath member 12b is thermally melted by applying a predetermined heat, and the core members 12a in the vicinity are bonded to each other by the melted sheath member 12b, so that the fiber aggregate 16 can be easily formed. Form (Fig. 3
(See (b)). That is, the plurality of core members 12
a forms the skeleton of the fiber assembly 16, and a low-density fiber assembly 16 in which many fine voids 14 exist between the core members 12 a is obtained. In addition, instead of the sheath member 12b, a thermoplastic resin having a melting point lower than that of the core member 12a may be applied in the form of a powder, or various binders that exhibit adhesiveness in response to heat may be applied. . In this case, the core member 12a itself becomes the fiber 12. The material of the core member 12a is not particularly limited, but any material may be used as long as the fiber diameter does not change with respect to a change in heat or the like applied upon bonding with the surrounding fibers 12. I can do it.

As means for fusing the cotton-like laminated body laminated by the cross layer by heating, a fiber as a material is laminated into a sheet-like material having a substantially uniform thickness, and heating air is passed through the sheet-like material. This is a method in which the temperature is increased uniformly while maintaining the ventilation state by contact, so as to have a predetermined thickness. This ventilation method has the feature of minimizing the variation in density depending on the location of the fiber assembly 16 to be obtained, whereby the core member 1 when compressed to near the limit in the heat compression step S2 described below is provided.
The shape collapse of 2a can be suppressed. It is preferable that the temperature to be applied is such that the sheath member 12b is melted and the cotton-like laminate can maintain the shape as the fiber aggregate 16. In the case of the present embodiment, it is approximately 120 to 135 ° C. It has become.

As the fiber diameter of the fiber 12, the thinner the fiber, the stronger the osmotic force can be exerted by the capillary force. However, if the diameter is too small, the mechanical strength of the fiber is reduced. Is suitable. The unit (decitex) used here is a unit indicating the thickness of a synthetic fiber or a chemical fiber specified by the International Organization for Standardization (ISO). One gram per 10,000 meters of fiber is defined as one decitex. I have. Crystalline polypropylene core member 1 suitably used in this embodiment
In the case of the fiber 12 composed of 2a and the sheath member 12b of low melting point polyethylene, about 10 μm corresponds to 1 dtex.

The fiber aggregate 16 has a molding density of 0.02 to 0.07 g / cm ³ , preferably 0.04 to 0.07 g / cm ^3.
It is formed so as to have a range of about 0.06 g / cm ³ .
If the molding density is less than 0.02 g / cm ³ , when the sheet-like fiber aggregate 10 is finally obtained, the density of the fibers 12 is too low to maintain a high diffusion penetration power, and If it exceeds 0.07 g / cm ³ , the density of the fibers 12 is too high, and even if the diffusion penetration power is high and the effective absorption power is sufficient,
There is a possibility that a sufficient absorption amount of the residual ink cannot be secured.

As a means for bonding the fibers 12 to each other, besides the resin or the like which is melted by heating as described above, it is also possible to use a binder which exhibits, for example, moisture adhesion. In this case, it is not necessary to perform heating in the fusion performed in this step S1 and in the heat compression step S2 described later, and an element such as moisture for the binder to exhibit adhesiveness is added during fusion or compression. What should I do?

In the subsequent heat compression step S2, the fiber assembly 16 obtained in the cotton wool / fusing step S1 is subjected to heat compression so that the above-mentioned capillary force (fiber diameter) is not impaired. This is the stage of obtaining the sheet-like fiber aggregate 10 compressed to the maximum.

More specifically, as shown in FIG. 4, both sides of the fiber assembly 16 to be subjected to the heat compression process in the compression direction are release papers 2.
0, 20 and pressurizing means 22, 22 such as a press equipped with a heating means 22a such as an electric heater under the predetermined pressure through the release papers 20, 20.
This is performed by maintaining the temperature at which b is sufficiently melted for a certain period of time. In the case of this embodiment, the temperature is 135 ° C., and the pressure is 8MP.
a and the holding time is 60 seconds.
Is performed.

The release paper 20 is preferably so formed that the sheet-like fiber assembly 10 obtained after heating under pressure is not thermally fused to the pressing means 22 by the sheath member 12b melted by heating. This is one means used so that the entire fiber assembly 16 is uniformly heated at the time of heating. For example, a sheet material having a large specific heat, such as urethane foam or a mesh-processed pet sheet, and having good releasability is preferably used. Has been adopted.

The density of the sheet-like fiber aggregate 10 obtained by performing the heat compression step S2 is 0.15 to 0.5.
g / cm ³ , that is, the density is increased to 7 to 10 times as compared with the fiber assembly 16, and a core member 12 a which is a skeleton of the sheet-like fiber assembly 10,
The ratio of the gap 14 to the gap 14, which is the gap a, is reduced to 1/7 to 1/10. This means that the ink droplets and the like absorbed in the voids 14 easily diffuse and penetrate into other parts due to the capillary force of the core member 12a. The higher the compression ratio from 16, the more noticeable.

With the increase of the diffusion and penetrating power, the ink is diffused not only in the region where the residual ink is absorbed, but also around the region. As a result, the entire volume of the sheet-like fiber assembly 10 is efficiently used for absorbing ink, and a large effective absorbing power can be exhibited. This means that even if the thickness of the sheet-like fiber aggregate is small and the volume is small, the effective absorption power is high and sufficient ink absorption ability can be exhibited.

However, if the density is too high, that is, if the pressure applied in the heat compression step S2 is too high, the core member 12a itself, which is the skeleton part, is deformed, and as a result, the capillary force varies depending on the part. As a result, a uniform and high diffusion penetration power cannot be obtained. This is because the capillary force is determined by the fiber diameter as described above.

It is desired that the thickness of the sheet-like fiber assembly 10 manufactured in this embodiment is 1 mm or less, preferably about 0.5 mm, from the size of the ink head to be attached. This thickness is determined by the compression ratio applied in the main heat compression step S2 and by adjusting the thickness of the fiber assembly 16. Specifically, if the compression ratio is set to 10, the fiber aggregate 16 must have a thickness of 5 mm in advance. Therefore, a step of slicing the fiber assembly 16 to a required thickness may be added prior to the main heat compression step S2.

The sheet-like fiber assembly 10 is subjected to required compression under heating in two stages, namely, a main compression stage S2 and the above-mentioned molding and fusing stage S1. ,
If this is to be performed only in the cotton wool / fusion step S1, the following difficulties are pointed out. That is, the dimensional stability of the finally obtained sheet-like fiber assembly 10 becomes low, and the surface thereof becomes wavy, a difference in thickness depending on the portion, a so-called thickness gradient occurs, and the yield is reduced. The compression ratio which is reduced at the same time when manufacturing the sheet-like fiber assembly 10 is increased, and the equipment required for the molding and fusing step S1 is increased in size.

The next post-processing step S3 is to impart a penetration aid to the sheet-like fiber aggregate 10 obtained through the steps so far and dry it to chemically increase the permeability, This is a stage in which the process is selectively performed depending on the type of ink used in the printer used.

As the permeation aid, an ionic or nonionic surfactant is preferable, and the surface tension of ink droplets to be absorbed is reduced to improve the wettability, and as a result, the permeability is improved. It is to let. Generally, the application of the penetration aid is performed by means such as impregnation so that the entire sheet-like fiber assembly 10 can be applied. Other physical properties required for the penetration aid include rewetability indicating the degree of chronological change in wettability.

By going through the steps S1, S2 and S3 up to this point, a sheet-like fiber aggregate having a desired thickness and diffusion permeability can be obtained. The final stage S4, which is finally performed, is a stage in which the sheet-like fiber assembly 10 is subjected to final processing into a predetermined shape, predetermined inspection, and the like to obtain a finished product.

The seed-like fiber aggregate thus obtained has a feature that its volume is effectively used and that it absorbs a liquid material such as ink very strongly. Use applications that take advantage of such features include, in addition to ink absorbers, refrigerator humidity controllers, air conditioner humidifying elements, dew condensation prevention panels, moisturizing liquid holders, fragrance core members or stamp pads. .

[0035]

As described above, according to the sheet-like fiber aggregate and the method for producing the same of the present invention, the fibers are laminated and laminated.
Further, the fiber aggregate obtained by fusion is subjected to further compression to increase the diffusion penetration force, thereby obtaining a sheet-like fiber aggregate in which the effective absorption of residual ink is improved.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a sheet-like fiber absorbent according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a process for producing a sheet-like fiber assembly according to an example.

FIG. 3 is a state diagram showing a state in which heat is applied to the fiber according to the example, with a part cut away.

FIG. 4 is a state diagram illustrating a thermal compression stage according to an example.

FIG. 5 is a process diagram showing an ink scraping process of a printer using a fiber assembly as an absorber.

FIG. 6 is a state diagram showing a state of ink absorption in a conventional absorber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Sheet-shaped fiber aggregate 12 Fiber 16 Fiber aggregate 20 Release paper

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B41J 2/185 B41J 3/04 102H D04H 1/56 102R 1/58 (72) Inventor Hiroki Ito Hadano, Kanagawa Prefecture 380-5, Ichihoriyamashita F-term in INOAC Technical Research Institute Co., Ltd. (Reference) 2C056 JB04 JB09 JC11 4L047 AA27 AB07 BA09 BA23 BB09 CB10 CC16

Claims (6)

[Claims] 1. A sheet-like fiber assembly obtained by laminating fibers (12) as a raw material to form a cotton-like laminate, and performing heat fusion and heat compression on the laminate. The fiber diameter is set in the range of 1 to 7 dtex, and the density of the sheet-like fiber assembly (10) is at least 0.15 g /
A sheet-shaped fiber aggregate set to be at least ³ cm ³ . 2. The thickness of the sheet-like fiber assembly (10)
The sheet-shaped fiber aggregate according to claim 1, which is set to 1 mm or less. 3. The sheet-like fiber assembly according to claim 1, wherein the sheet-like fiber assembly (10) is provided with a penetration aid such as a surfactant. 4. A method of manufacturing a sheet-like fiber aggregate by laminating fibers (12) as a material to form a cotton-like laminate, and subjecting the fiber to heat fusion and thermal compression to produce a sheet-like fiber aggregate. Release papers (20, 20) are interposed on both sides of the fiber aggregate (16) obtained by performing the heat fusion, and after heat-pressing through these release papers (20, 20), the release paper
A method for manufacturing a sheet-like fiber assembly, wherein the sheet-like fiber assembly (10) is manufactured by removing (20, 20). 5. The pressurizing condition of the thermal compression is as follows:
The method for producing a sheet-like fiber assembly according to claim 4, wherein the temperature is set at 140 ° C and the pressure is in the range of 7 to 9 MPa. 6. The method for producing a sheet-like fiber assembly according to claim 4, wherein the sheet-like fiber assembly (10) obtained by pressurization is provided with a penetration aid by impregnation.