JP5089905B2 - Ink cartridge and method of manufacturing ink cartridge - Google Patents

Description

The present invention relates to an ink cartridge used for supplying ink to a printer, and more particularly to a method of manufacturing an ink cartridge having a holding structure for holding a packing in a hole of an ink discharge portion of the ink cartridge.

The elastic packing is used in various fields with respect to the joint portion of the pipe through which liquid such as a water pipe circulates. However, since an O-ring is generally used, it is a portion formed in advance by the front and rear projections. Inserted and used. In particular, since the ink cartridge is attached to and detached from a coupling portion such as an ink needle in order to supply ink to an ink jet printer or a head, the O-ring is an important member. At this time, the ink supply needle of the printer is relatively inserted into the hole of the ink discharge portion of the ink cartridge. In this case, the O-ring has an outer peripheral surface that is in close contact with the peripheral wall in the hole of the ink discharge portion in order to prevent ink leakage from between the ink supply needle and the peripheral wall of the hole of the ink discharge portion. When the ink supply needle enters, the ink supply needle comes into close contact with the inner peripheral surface of the O-ring. On the other hand, since the ink discharge portion is a tube for supplying ink, it is known that a film is stretched to prevent ink leakage when the cartridge is not used or sold. This film is disposed so as to block the ink discharge portion and is attached to the peripheral wall of the hole. At the time of mounting, mounting is started by being broken by a coupling member (see Patent Document 1 and Patent Document 2). ).

In contrast to Patent Document 1 and Patent Document 2, Patent Document 3 discloses a film that sandwiches an O-ring by bringing the position of the O-ring closer to the position of the film. The film is disposed so as to close the hole in the ink discharge portion and is attached to the peripheral wall of the hole. However, this document does not describe the problem of the O-ring coming out when the ink needle is attached to or detached from the O-ring.

Japanese Patent Laid-Open No. 4-7157 Japanese Patent Laid-Open No. 4-110157 Japanese Patent Laid-Open No. 5-229133

In each of Patent Documents 1, 2, and 3, the film has an effect of preventing the internal O-ring from coming off at the time of sale. However, when the ink cartridge is temporarily removed from the printer, the film is in close contact with the ink supply needle. If the O-ring moves toward the opening of the ink discharge portion, there is a problem that the O-ring hits the film while being in close contact with the ink needle and further passes through the film. Furthermore, in a severe situation, the film may be peeled off from the peripheral wall of the hole of the ink discharge portion. As described above, it is difficult for Patent Documents 1, 2, and 3 to reliably hold the O-ring in the hole of the ink discharge portion.

An object of the present invention is to recognize the above-mentioned problem latent in the conventional patent document in examining the holding structure of the elastic packing, and what kind of elastic packing is arranged in the hole of the ink discharge portion of the ink cartridge. It is another object of the present invention to provide a holding structure and a method for forming a holding portion that ensure the holding of the structure, and further an ink cartridge and a manufacturing method thereof. An object of the present invention is to provide a holding structure that is particularly effective when an elastic packing provided with a pull-out prevention mechanism is used, an ink cartridge including the holding structure, and a method for manufacturing the same.

The present invention includes an ink storage portion for storing ink, and a holding structure that is provided in the ink ejection portion and has a stopper for an elastic packing that compresses and holds the ink supply needle that is relatively inserted. In the ink cartridge,
The holding structure is an insertion side of the ink supply needle with respect to the packing, a thermoplastic resin ink discharge portion, and a thermoplastic resin that covers the ink discharge portion at a tip portion of the thermoplastic resin ink discharge portion After the ink leakage prevention film is placed, the tip is held by applying heat and pressure, and the tip is softened and crushed. Projecting inward and compressing and holding the packing so as to be in intimate contact with the stopper and the inner surface of the ink discharge unit; and molding of the overhanging holding unit and heat-welding to the overhanging holding unit said ink leakage out preventing film which performs sealing of the ink discharge portion, were closed,
The packing has a convex portion that further improves adhesion by being pressed against the inner surface of the ink discharge portion,
The ink cartridge is characterized in that the adhesion is improved by the overhanging holding portion.

The present invention also relates to a holding structure for holding a packing in a hole of an ink discharge portion provided in an ink cartridge of a thermoplastic resin, and is formed by softening a tip portion of the ink discharge portion. A holding part that projects inward of the hole is included. Furthermore, the film piece which covers the said hole heat-welded to the said front-end | tip part simultaneously with the softening of the said front-end | tip part can be included.

The present invention also relates to a method of forming a holding portion for holding a packing in a hole of an ink discharge portion provided in the ink cartridge, and relates to a thermoplastic resin ink cartridge having an ink discharge portion having a protruding tip portion. Preparation, inserting a packing into the hole of the ink discharge part, applying heat pressure to the tip part of the ink discharge part, and thereby, until a part of the tip part protrudes inward of the hole Including softening this. Applying heat pressure to the tip of the ink ejection unit includes pressing a heated head against the tip. Furthermore, the present invention is another method for forming a holding portion for holding a packing in a hole of an ink discharge portion provided in a thermoplastic resin ink cartridge, wherein the ink discharge portion having a raised tip portion is provided. Preparing an ink cartridge provided, inserting a packing into a hole of the ink discharge part, disposing a film piece covering the hole at a tip part of the ink discharge part, and forming the film at a tip part of the ink discharge part Applying a thermal pressure through the substrate, thereby softening the film piece until it is heat welded to the tip and a portion of the tip overhangs into the hole. Applying heat pressure to the tip of the ink discharge unit includes pressing a heated head through the film to the tip. The holding structure of the present invention is a holding structure that is provided in an ink cartridge and has a stopper for an elastic packing that compresses and holds an ink supply needle that is relatively inserted, and the ink supply needle is inserted more than the packing. A holding structure including a thermoplastic resin ink discharge portion and a protruding holding portion for compressing and holding the packing against the stopper by softening and molding the thermoplastic resin ink discharge portion It is. Preferably, the holding structure further includes an ink leakage prevention film that covers the ink discharge part that is thermally welded to the tip part as the tip part is softened, and the packing further supports the inner surface of the ink discharge part. It has a convex part which improves adhesiveness, and it is a more preferable condition that the adhesiveness is improved by the overhanging holding part.

The present invention also includes an ink storage portion for storing ink, a holding structure provided in the ink discharge portion, and a stopper for an elastic packing that compresses and holds the ink supply needle that is relatively inserted, In the manufacturing method of the ink cartridge having
Forming an overhanging holding portion for compressing and holding the packing inserted into the thermoplastic resin ink discharge portion in close contact with the stopper, wherein the thermoplastic resin ink discharge portion After the thermoplastic resin ink leakage prevention film covering the ink discharge part is placed at the tip part, heat and pressure are applied to the tip part to hold it, and the tip part is softened and crushed to, have a step of sealing said ink discharge portion by heat welding the film to the projecting holding portion at the same time closely the gasket against the stopper and the ink discharge portion inner surface,
The packing has a convex portion that further improves adhesion by being pressed against the inner surface of the ink discharge portion,
The ink cartridge manufacturing method is characterized in that the adhesion is improved by the overhanging holding portion.

Further, the cartridge of the present invention has an ink storage portion for storing ink, and a holding structure provided in the ink discharge portion and having a stopper for an elastic packing that compresses and holds the ink supply needle that is relatively inserted. The holding structure is formed by softening and molding the thermoplastic resin ink discharge portion and the thermoplastic resin ink discharge portion on the insertion side of the ink supply needle from the packing. And an overhanging holding portion that compresses and holds the packing against the stopper. Furthermore, it is preferable to include ink stored in the ink storage portion, and an ink leakage prevention film that covers the ink discharge portion that is thermally welded to the distal end portion together with the softening of the distal end portion. Moreover, it is also preferable that the packing has a convex portion that improves adhesion to the inner surface of the ink discharge portion, and the adhesion is improved by the overhanging holding portion. The ink cartridge manufacturing method of the present invention includes an ink storage portion for storing ink, and a holding member provided in the ink discharge portion and having a stopper for an elastic packing that compresses and holds the ink supply needle that is relatively inserted. And a packing inserted into the thermoplastic resin ink discharge portion with respect to the stopper, and the thermoplastic resin ink discharge portion is softened and molded with respect to the stopper. Forming an overhanging holding portion for compressing and holding the ink cartridge. Furthermore, when softening the ink discharge portion of the thermoplastic resin, an ink leakage prevention film is disposed in advance on the front end portion of the ink discharge portion, and the front end portion of the ink discharge portion is interposed via the film. It preferably includes applying hot pressure. Further, it is preferable that a convex portion for improving the adhesion with respect to the inner surface of the ink discharge portion is provided, and the adhesion is improved by the overhanging holding portion. In the present invention, it is sufficient that at least a part of the end portion side of the ink discharge portion of the thermoplastic resin is a thermoplastic resin, so that the overhang holding portion can be formed. The overhang portion may be formed in advance, and the film for preventing ink leakage may be attached using the outer surface of the overhang portion. At this time, the adhesive strength of the film can be improved, which is preferable.

According to the present invention, the holding portion that is formed by softening the tip portion of the ink discharge portion of the ink cartridge and projects to the inside of the hole does not protrude the packing disposed in the hole from the hole. And prevents this from being retained in the hole. In addition, the film piece that is heat-welded to the tip portion simultaneously with the softening of the tip portion of the ink discharge portion and covers the hole prevents ink leakage from the ink discharge portion. The holding part is integral with the ink discharge part and has a relatively large rigidity. From this, when the ink cartridge installed in the printer is temporarily removed, the packing may move together with the supply needle of the printer toward the open end in the hole of the ink discharge portion, The holding part stops the movement of the packing and holds it in the ink discharge part. The holding part for the packing is prepared by preparing a thermoplastic resin ink cartridge having an ink discharge part having a raised tip part, and after inserting the packing into the hole of the ink discharge part, the tip of the ink discharge part For example, it can be formed by applying a hot pressure to the part by pressing a heated head and softening it until a part of the tip part protrudes inward of the hole. The holding portion including the film piece includes a film piece covering the hole on the tip portion of the ink discharge portion after the packing is inserted into the hole of the ink discharge portion, and the film is disposed on the tip portion. It is possible to form the film piece by softening it until the film piece is thermally welded to the tip and a part of the tip protrudes inward of the hole.

Since the holding structure of the present invention is a holding structure including an extending holding part for compressing and holding the packing against the stopper by softening and molding the ink discharge part of the thermoplastic resin, from the previous invention, The effect of preventing the packing from being removed is excellent, and at the same time, the adhesion to the ink supply needle can be improved. Conversely, the packing itself can be as simple as an O-ring. If the packing has a structure having a convex portion that improves the adhesion to the inner surface of the ink discharge portion, the adhesion can be improved by the overhanging holding portion.

Accordingly, the cartridge of the present invention has an ink storage portion for storing ink, and a holding structure provided in the ink discharge portion and having a stopper for an elastic packing that compresses and holds the ink supply needle that is relatively inserted. An overhang holding portion that compresses and holds the packing against the stopper by softening an ink discharge portion of a thermoplastic resin on the insertion side of the ink supply needle with respect to the packing. Therefore, even if the ink supply needle is repeatedly attached and detached, the conventional problem of packing removal does not occur.

The method of manufacturing an ink cartridge according to the present invention is simple and reliable by forming an overhanging holding portion that compresses and holds an elastic packing that compresses and holds an ink supply needle that is relatively inserted with respect to a stopper. The cartridge of the invention can be manufactured. In particular, when softening the ink discharge portion of the thermoplastic resin, an ink leakage prevention film is disposed in advance on the front end portion of the ink discharge portion, and the front end portion of the ink discharge portion is interposed via the film. By applying hot pressure, excellent productivity and more reliable effects can be obtained. As described above, also in this case, using a packing having a convex portion that improves the adhesion to the inner surface of the ink discharge portion improves the adhesion force of the convex portion to the inner diameter of the ink supply portion, while A retaining effect can be obtained.

Referring to FIG. 1, an example of a thermoplastic resin ink cartridge to which the present invention is applied, for example, an ink cartridge 10 made of polypropylene, polystyrene, polyethylene or the like is shown. In the practice of the present invention, it is only necessary to have a thermoplastic resin portion to such an extent that at least a protruding holding portion described later can be formed by at least a part of the ink supply portion. The ink cartridge 10 includes an ink discharge unit 12 for discharging the ink stored in the inside 11 to the outside. The ink discharge unit 12 has a hole 13 at the bottom of the ink cartridge 10 that opens downward, and a tip 14 that defines an open end of the hole.

The illustrated ink cartridge 10 is not filled with ink. The ink is injected into the ink cartridge 10 through the hole 16 provided on the top of the ink cartridge 10 after the arrangement of the packing described later in the ink discharge portion 12, that is, in the hole 13, and the formation of the holding portion of the packing. Inside the ink cartridge 10, an ink absorbing porous body 18 made of urethane, felt or the like for holding the injected ink is accommodated. In the example shown in the drawing, the hole 13 of the ink discharge portion is composed of two cylindrical spaces having a small diameter and a large diameter that are continuous with each other. The small-diameter space and the large-diameter space are located above and below, respectively. The surface portion that changes from the small diameter to the large diameter corresponds to the stopper 13A shown in FIG. Reference numeral 13B denotes an inner surface of the ink supply portion to which a convex portion 22A of an elastic packing described later is pressed.

When the ink cartridge 10 filled with ink is set in a printer (not shown), the hole 13 of the ink discharge portion 12 of the ink cartridge receives insertion of an ink supply needle (not shown) of the printer. At this time, the ink filling the hole 13 of the ink discharge unit 12 is supplied to the printer through the ink supply needle in the hole 13. A packing 22 for sealing between the ink supply needle and the peripheral wall 20 (FIG. 2) defining the inside of the hole 13 is disposed so that the ink in the hole 13 of the ink discharge section 12 does not leak to the outside. Is done.

As shown in FIG. 2, the packing 22 is arranged in the hole 13 of the ink discharge section 12 with the top of the ink cartridge 10 turned upside down, that is, with the tip 14 of the ink discharge section 12 of the ink cartridge facing upward. This can be done by inserting 22.

The illustrated packing 22 has a cylindrical shape, and has a small-diameter and large-diameter outer peripheral surface and an inner peripheral surface having substantially the same diameter, and the longitudinal cross-sectional shape thereof is L-shaped as a whole.

When the packing 22 is disposed in the hole 13 of the ink discharge portion, the outer peripheral surfaces of the small diameter and the large diameter of the packing 22 are in close contact with the peripheral wall 20 that defines the small diameter and large diameter space of the hole 13. At this time, a small space 24 (FIG. 3) is generated between the upper end of the packing 22 and the upper end of the hole 13. The small space 24 is filled with ink supplied to the ink supply needle of the printer.

The packing 22 disposed in the hole 13 of the ink discharge unit allows the ink supply needle of the printer to be inserted into the hole 13 to be inserted. At this time, the ink supply needle is in close contact with the inner peripheral surface of the packing 22. As a result, leakage of the ink in the small space 24 in the hole 13 to the outside is prevented.

The front end portion 14 of the ink discharge portion 12 of the ink cartridge is slightly raised from the other portion of the ink discharge portion 12. In the illustrated example, it has an annular plane shape surrounding the open end (lower end) of the hole 13. Further, in the illustrated example, a depth corresponding to the raised height of the front end portion 14 of the ink discharge portion between the open end of the hole 13 and the end surface of the large diameter portion of the packing 22 disposed in the hole 13. The size of the packing 22 is set so that there is a gap 26 (FIG. 3). Instead of this, the size of the packing 22 can be set so that there is a gap 26 having a depth larger than the raised height of the tip portion 14.

The packing 22 is held in the hole 13 of the ink discharge portion by the holding structure 28 (FIG. 4) according to the present invention.

The holding structure 28 has a holding portion 30 that protrudes inward at the open end of the hole 13. The holding part 30 is formed by softening the tip part 14 formed of the raised thermoplastic resin of the ink discharge part 12 by applying a temperature equal to or higher than its softening temperature together with pressure, and growing and deforming it toward the inner diameter side. Yes.

In the illustrated example, the holding part 30 has an annular shape, occupies a part of the gap 26, and is in contact with the end face of the packing 22 in the hole 13. For this reason, the packing 22 is surely secured by the holding portion 30 so as not to go outside in the hole 13 and in the illustrated example so as not to move in the axial direction in the hole 13. Is retained. Since the holding part 30 is formed by softening the tip part 14, the holding part 30 is integrated with the ink ejection part 12 and has rigidity. For this reason, when the ink supply needle of the printer is removed relative to the packing 22, the packing 22 is stably held in the hole without coming out of the hole 13.

The holding portion 30 may be discontinuous instead of the illustrated example in which the holding portion 30 is annular in the circumferential direction of the hole 13. Moreover, it can replace with the example which makes this a cyclic | annular thing about packing 22, and can be made into a ring-shaped thing (O ring shown in FIG. 5, or D ring shown in FIG. 6). Each of the packings 22 composed of the O-ring and the D-ring is disposed in the large-diameter cylindrical space of the hole 13. These packings 22 are in close contact with the wall surface 20 that defines the large-diameter cylindrical space of the hole 13 on the outer peripheral surface thereof. Further, the inner peripheral surface of the packing 22 is elastically in close contact with the ink supply needle of the printer when passing through the packing.

The holding part 30 can be formed as follows.

After preparing the ink cartridge 10 having the above-described raised tip portion 14 and inserting the packing 22 into the hole 13 of the ink discharge portion, the tip portion 14 of the ink discharge portion faces up, and the pressure is applied to the tip portion. Is added (see FIG. 3). Thus, the peripheral portion of the hole 13 which is a part of the tip portion 14 is softened until it protrudes inward of the hole 13 (see FIG. 4).

The application of the thermal pressure to the tip portion 14 of the ink discharge unit 12 is performed by pressing the end surface of the heated head 32 (FIG. 3) having a cylindrical shape, a prismatic shape, or the like against the tip portion 14. Can do.

The peripheral portion of the hole 13 in the tip portion 14 is softened under the heating and pressurization by the pressing of the head 32 and then crushed, so that it protrudes from the peripheral edge of the hole 13 toward its axis.

After the overhang of a part of the tip end portion 14 occurs, the head 32 is pulled away from the tip end portion 14 and the application of the heat pressure is stopped. As a result, the protruding portion is cooled and solidified. The cooled and solidified material forms the holding unit 30. In this embodiment, the head temperature is about 20 degrees higher than the softening temperature of the resin, and the pressure is continuously applied to form the overhang holding portion. At this time, the temperature of the head gradually decreases due to thermal diffusion and falls below the softening temperature of the resin, so that compression and holding of the packing can be achieved while the head is being pressed. Thereafter, by removing the head from the film and packing, the temperature of the head is increased, and the continuous production can be continued. For the present invention, it is preferable to configure an overhanging holding portion for compressing and holding the packing as in the latter manufacturing method. The description of each embodiment of the present invention can be interpreted as a configuration to which either manufacturing method is applied.

The temperature, pressure, and time that should be applied to the tip end portion 14 vary depending on the softening point (corresponding to the deformation temperature) of the resin that constitutes the ink discharge portion. The above shape and deformation, preferably the compression holding state of the packing can be formed, for example, set within the range of 120 to 200 ° C., 0.2 to 15 kgf and 0.5 to 10 seconds. it can.

A film piece 34 (FIG. 4) for temporarily sealing the hole 13 in order to prevent ink leakage until the ink cartridge 10 filled with ink is used after the holding portion 30 is formed. It is attached to the tip part 14 of 12.

About attachment of the film piece 34 to the front-end | tip part 14, it can replace with performing this after formation of the holding | maintenance part 30, and can be performed simultaneously with formation of the holding | maintenance part 30 as follows.

That is, after the packing 22 is inserted into the hole 13, a thermoplastic resin film piece 34 covering the hole 13 is disposed on the tip part 14 prior to application of heat pressure to the tip part 14 of the ink discharge part.

Next, hot pressure is applied to the distal end portion 14 via the film piece 34. More specifically, the end face of the heated head 32 is pressed from the top of the film piece 34 to the tip portion 14.

Thereby, a part of the film piece 34 and a part of the tip part 14 are softened, the film piece 34 is thermally welded to the surface of the tip part 14, and a part of the tip part 14 is protruded inward of the hole 13. Can do.

Thereafter, when the head 32 is removed, the film piece 34 and the tip portion 14 are naturally cooled, the softened portions are solidified, the film piece 34 is fixed to the tip portion 14, and the protruding portion of the tip portion 14 is solidified. . The temperature, pressure and time to be applied to the tip portion 14 can be set in the same manner as described above.

FIG. 7 is a diagram for explaining the main part of the present invention, which is a modification of FIG. 2. In the manufacture, the head temperature is 25 degrees higher than the softening temperature of the resin and pressure is continuously applied. , To form a tip-out holding portion. At this time, the temperature of the head gradually decreases due to thermal diffusion and falls below the softening temperature of the resin. Therefore, the method is carried out by a method that can achieve compression and holding of the packing while the head is being pressed. Thereafter, by separating the head from the film, an increase in the temperature of the head can be obtained, and subsequent continuous production becomes possible. Here, the packing 22 has a convex portion 22A that improves adhesion to the inner surface of the ink discharge portion, and this adhesion is improved by the overhanging holding portion.

In the example shown in the drawing, the hole 13 of the ink discharge portion is composed of two cylindrical spaces having a small diameter and a large diameter that are continuous with each other. The small-diameter space and the large-diameter space are located above and below, respectively. The surface portion that changes from the small diameter to the large diameter corresponds to the stopper 13A shown in FIG. Reference numeral 13B denotes an inner surface of the ink supply portion to which a convex portion 22A of an elastic packing described later is pressed.

With this configuration, the holding mechanism, the ink cartridge having the holding mechanism, and the manufacturing method thereof, as described above, compress and hold the packing against the stopper by softening and molding the ink discharge portion of the thermoplastic resin. Since the holding structure includes an overhanging holding portion, the effect of preventing the packing from being removed is superior to that of the previous invention, and at the same time, the adhesion to the ink supply needle can be improved. Conversely, the packing itself can be as simple as an O-ring. If the packing has a structure having a convex portion that improves the adhesion to the inner surface of the ink discharge portion, the adhesion can be improved by the overhanging holding portion.

It is a longitudinal cross-sectional view of an ink cartridge. FIG. 4 is a partial vertical cross-sectional view of an ink cartridge showing an ink discharge portion and a cross-sectional view of a packing. FIG. 4 is a partially enlarged longitudinal sectional view of an ink cartridge showing an ink discharge portion and a partial side view of a head which is a heat pressure applying unit. FIG. 3 is a partially enlarged longitudinal sectional view of an ink cartridge showing a packing holding structure. FIG. 5 is a partially enlarged longitudinal sectional view of an ink cartridge showing a packing holding structure of another example. FIG. 10 is a partially enlarged longitudinal sectional view of an ink cartridge showing a packing holding structure of still another example. FIG. 4 is a partial longitudinal sectional view of an ink cartridge showing an ink discharge portion and an anti-cross sectional view of an elastic packing having a convex portion.

DESCRIPTION OF SYMBOLS 10 Ink cartridge 12, 14 Ink discharge part and its front-end | tip 13 Hole 22 of ink discharge part Packing 22A Protrusion part 28 Holding structure 30 Packing part 32 Head 34 for providing a hot pressure Film piece

Claims (2)

In an ink cartridge having an ink storage portion for storing ink, and a holding structure having a stopper for an elastic packing that is provided in the ink discharge portion and is compressed and held with respect to an ink supply needle that is relatively inserted,
The holding structure is an insertion side of the ink supply needle with respect to the packing, a thermoplastic resin ink discharge portion, and a thermoplastic resin that covers the ink discharge portion at a tip portion of the thermoplastic resin ink discharge portion After the ink leakage prevention film is placed, the tip is held by applying heat and pressure, and the tip is softened and crushed. Projecting inward and compressing and holding the packing so as to be in intimate contact with the stopper and the inner surface of the ink discharge unit; and molding of the overhanging holding unit and heat-welding to the overhanging holding unit said ink leakage out preventing film which performs sealing of the ink discharge portion, were closed,
The packing has a convex portion that further improves adhesion by being pressed against the inner surface of the ink discharge portion,
The ink cartridge is characterized in that the adhesion is improved by the overhanging holding portion. Manufacture of an ink cartridge having an ink storage portion for storing ink, and a holding structure having a stopper for an elastic packing that is provided in the ink discharge portion and is compressed and held with respect to an ink supply needle that is relatively inserted In the method
Forming an overhanging holding portion for compressing and holding the packing inserted into the thermoplastic resin ink discharge portion in close contact with the stopper, wherein the thermoplastic resin ink discharge portion After the thermoplastic resin ink leakage prevention film covering the ink discharge part is placed at the tip part, heat and pressure are applied to the tip part to hold it, and the tip part is softened and crushed to, have a step of sealing said ink discharge portion by heat welding the film to the projecting holding portion at the same time closely the gasket against the stopper and the ink discharge portion inner surface,
The packing has a convex portion that further improves adhesion by being pressed against the inner surface of the ink discharge portion,
The method for manufacturing an ink cartridge is characterized in that the adhesion is improved by the overhanging holding portion.

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