Abstract:
A method for direct blow molding including steps of: inserting a blowing jig for blowing air into an inside of a prison; locating the two dies to positions so that the two dies face each other across the parison, wherein two dies have a inner space shape, of which overlapping section with the blowing jig is smaller than the outside diameter of a parison; forming the overlapping section between the parison and the blowing jig, to be smaller than an outside diameter of the parison by using a space between the two dies and the blowing jig when the blowing jig is inserted into an inside of the parison and when the two dies are combined together; and depositing a metal layer to the surface by vapor deposition.

Description:
This patent application claims priority from a Japanese Patent Application No. 2003-294641 filed on Aug. 18, 2003, the contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a method for a direct blow molding. More particularly, the present invention relates to a method for a direct blow molding suitable for a manufacturing of a liquid accommodating container. 
   2. Description of the Related Art 
   An ink-jet type recording apparatus, which is an example of a liquid ejecting apparatus, does recoding by ejecting ink droplets onto a recording medium from a liquid ejecting head. The ink-jet type recording apparatus includes a liquid cartridge for holding ink, which is detachably mounted on the ink-jet type recording apparatus. The liquid cartridge supplies ink to the liquid ejecting apparatus while mounted on the liquid ejecting apparatus. US Laid-open patent application No. 2002/0154200. 
   It is considered that the liquid cartridge is manufactured by forming a liquid accommodating container made of resin in a resin case. In order to supply the liquid to the exterior of the resin case, it is necessary to form the liquid accommodating container so that a part of the container may be salient and the part is exposed to the exterior of the resin case as a liquid supplying part. Sometimes, bumps are provided at the outside of the supplying part to fix the supplying part to the resin case. It is desired to manufacture the liquid accommodating container at low cost having such shapes described above. 
   SUMMARY OF THE INVENTION 
   To achieve the above and other objects, according to the first aspect of the present invention, a method for direct blow molding, includes steps of: preparing two dies of which an overlapping section overlaps with a blowing jig for blowing air and wherein a cross section area of at least a part of the overlapping section is smaller than a cross section area of a parison when the two dies are combined together; locating the two dies to each positions so that the two dies face each other across the parison; and forming the overlapping section between the parison and the blowing jig. The step of forming the overlapping section between the parison and the blowing jig comprises steps of: inserting the blowing jig into an inside of the parison; combining the two dies together, forming the overlapping section between the parison and the blowing jig to be smaller than an outside diameter of the parison by using a space between the two dies and the blowing jig. According to the method for direct blow molding, a structure having some parts of which size is smaller than that of parison can be formed. 
   The step of preparing two dies may include a step of preparing a die for manufacturing a liquid accommodating container for keeping a liquid which are to be supplied to a liquid ejecting apparatus to record by ejecting the liquid; wherein the liquid accommodating container formed by the die comprises a supplying part, which supplies the liquid to the liquid ejecting apparatus, wherein the supplying part protrudes from the liquid accommodating container, is integrated with the liquid accommodating container, and is a hollow member allowing communication with a inside part of the liquid accommodating container. The step of forming the overlapping section between the parison and the blowing jig may include a step of forming the supplying part by using the space between the two dies and the blow jig. The method may further comprise a step of: blowing air from the blowing jig to form the parison to a shape of the liquid accommodating container. Thus, according to the direct blow molding, both the main body of the liquid accommodating container and the supplying part can be formed simultaneously. Therefore, the liquid accommodating container can be manufactured at low cost. 
   The liquid accommodating container may be mounted with the liquid ejecting apparatus with being held in a case; and the case may comprise a hole through which the supplying part is exposed to an exterior. The step of inserting the blowing jig into an inside of the parison may include a step of: inserting the blowing jig of which shapes of cross section are different and wherein the number of the shapes is equal to or greater than two, and the step of forming the overlapping section between the parison and the blowing jig further may comprise steps of: forming a root part of the supplying part so that an outside diameter of the root part becomes smaller than an inside diameter of the hole; and forming a tip part of the supplying part so that an outside diameter of the tip part becomes greater than the hole. In this case, the supplying section can be formed simultaneously with the main body of the liquid accommodating container. Therefore, the liquid accommodating container can be manufactured at low cost. 
   The parison may include a low density polyethylene layer, an ethylene-vinylalcohol copolymer layer and a liner low density polyethylene layer in an order of the low density polyethylene layer, the ethylene-vinylalcohol copolymer layer and the liner low density polyethylene layer from inner side, and the liquid accommodating container may be formed by resin which is stacked with the low density polyethylene, the ethylene-vinylalcohol copolymer and the liner low density polyethylene in the order of the low density polyethylene, the ethylene-vinylalcohol copolymer and the liner low density polyethylene. Since the liquid accommodating container includes the ethylene-vinylalcohol copolymer layer, the atmospheric air cannot easily transmit the body of the case. Therefore, it is not so easy for the air to solve in the liquid. 
   The summary of the invention does not necessarily describe all necessary features of the present invention. The present invention may also be a sub-combination of the features described above. The above and other features and advantages of the present invention will become more apparent from the following description of the embodiments taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an ink cartridge. 
       FIG. 2  is an exploded perspective view of the ink cartridge. 
       FIG. 3  is a side view of an ink accommodating container. 
       FIG. 4  is a top view of the ink accommodating container. 
       FIG. 5A  is A-A sectional view of  FIG. 4 . 
       FIG. 5B  is an enlarged view of the area surrounded by chained line in  FIG. 5A . 
       FIG. 6A  is a sectional view of the ink accommodating container  100  in a longitudinal direction when the ink accommodating container is filled with ink. 
       FIG. 6B  is a sectional view of the ink accommodating container in a longitudinal direction when the ink accommodating container is substantially empty. 
       FIG. 7  is a perspective view of the ink accommodating container when the ink accommodating container is substantially empty. 
       FIG. 8  is a perspective view of the die used for the manufacture of the ink accommodating container. 
       FIG. 9  is a plan view of the die included in the die. 
       FIG. 10  is an A-A sectional view of the die in  FIG. 9 . 
       FIG. 11  is a sectional view of the die into which the blowing jig and the parison  400  are inserted. 
       FIG. 12  is an enlarged view of the area surrounded by broken line. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  is a perspective view of the ink cartridge  10  according to an embodiment of the present invention.  FIG. 2  is an exploded perspective view of the ink cartridge  10 . The ink cartridge  10  is mounted with the ink-jet recording apparatus which ejects the ink to the recording medium such as a recording paper to record, and supplies the ink to the ink-jet recording apparatus. The ink cartridge  10  includes a resin case  20  and an ink accommodating container  100  which is accommodated in the resin case  20  and made of flexible resin. Each of the outer shape of the resin case  20  and the inner space shape of the resin case  20  is rectangular parallelepiped and the resin case  20  is sandwiched between an upper cover  40  and a bottom cover  60 . The upper cover  40  and the bottom cover  60  are in a plane symmetry. The shape of the main body of the ink accommodating container  100  is rectangular parallelepiped and holds the ink inside. The ink accommodating container  100  includes a supplying part  120  on a front edge face  101  which extends along a longitudinal direction of the main body, and the supplying part  120  supplies the ink to the ink-jet recording apparatus. The shape of the supplying part  120  is cylindrical and is exposed to the exterior of the resin case  20  from a circular opening which is formed by the assembly of an opening  42  at the upper cover  40  and an opening  62  at the bottom cover  60 . For example, the ink accommodating container  100  is manufactured by the direct blow molding method. When the ink accommodating container is filled up with the ink, there is almost no clearance in the resin case  20 . Thus, the ink cartridge  10  can hold the ink efficiently in the inner space. In addition, a section for keeping the ink can be formed without welding the film to the inner face of the resin case  20 . Therefore, the number of the manufacturing process can be reduced. 
   In the ink accommodating container  100 , a side face  102  and a side face  103 , which are perpendicular to the front edge face  101  and they are also faced with each other, are folded into an inside of the ink accommodating container  100  as the ink is being supplied from the ink accommodating container  100 . In addition, both an upper face  104  and a bottom face  106  are also folded into the inside of the ink accommodating container  100 . For this reason, the amount of the ink which remains inside the ink accommodating container  100  decreases. 
     FIG. 3  is a side view of the ink accommodating container  100 . The side face  102  includes four diagonal fold lines  112  extending from the four corners of the side face  102  to form two isosceles triangles and the side face  102  further includes a middle fold line  114  connecting intersecting points  112   a  and  112   b  corresponding to an intersection of two diagonal fold lines  112  which are located above and below, respectively. For example, each of the four diagonal fold lines  112  is on an angle of 45 degrees with each side which forms the side face  102  and extends until each of diagonal fold lines  112  meets the other diagonal fold line  112 . The middle fold line  114  extends in parallel with both an upper side and a bottom side at the midway between the upper side and the bottom side of the side face  102 . A side face  103  has the same configurations, i.e. four diagonal fold lines  112  and a middle fold line  114 , as those of the side face  102 . Therefore, the side face  102  and the side face  103  are folded into the inside of the ink accommodating container  100  along the four diagonal fold lines  112  and the middle fold line  114  as the ink is supplied from the ink accommodating container  100  to the ink-jet recording apparatus. 
     FIG. 4  is a top view of the ink accommodating container  100 . In the case of manufacturing the ink accommodating container  100  by the direct blow molding method, since the thickness of each of front edge face  101  and rear edge face  105  is formed to be thicker than that of other faces, it is not so easy to fold the front edge face  101  and the rear edge face  105 . Thus, according to the present embodiment of the ink accommodating container  100 , each of the upper face  104  and the bottom face  106  includes two assist fold lines  116 . One of the assist fold line  116  is formed in parallel with the front edge face  10 . The length between the assist fold line  116  and the front edge face  101  is about half of the length between the upper face  104  and the bottom face  106 . The other assist fold line  116  is formed in parallel with the front edge face  101 . The length between the assist fold line  116  and the rear edge face  105  is about half of the length between the upper face  104  and the bottom face  106 . Accordingly, both the upper face  104  and the bottom face  106  are folded inside, as the side face  102  and the side face  103  is folded. In this case, a vicinity of the front edge face  101  of each of the rear edge face  105  and the upper face  104  is in parallel with the front edge face  101  and a vicinity of the rear edge face  105  of each of the upper face  104  and the rear edge face  105  is in parallel with the rear edge face  105 . 
     FIG. 5A  is A-A sectional view of  FIG. 4 . The assist fold lines  116  are formed as a linear groove on the upper face  104  or on the bottom face  106 . Accordingly, the upper face  104  and the bottom face  106  can be easily folded along the assist fold lines  116 . 
   In addition, in the supplying part  120 , outside diameter of each of the tip part  124  and the inside diameter of the tip part  124  is larger than that of the root part  122 . The outside diameter of the root part  122  is a little smaller than an inside diameter of a circular opening which are formed by both the opening  62  of upper cover  40  and the opening  62  of the bottom cover  60 . The outside diameter of the tip part  124  is larger than the inside diameter of this opening. Accordingly, the supplying part  120  is securely fixed to the resin case  20 . 
     FIG. 5B  is an enlarged view of the area surrounded by chained line in  FIG. 5A . Flexible material which forms the ink accommodating container  100  is a resin film, which is stacked with a first base layer  131 , a gas barrier layer  132 , a second base layer  133 , and a metal layer  134  in the order of the first base layer  131 , the gas barrier layer  132 , the second base layer  133 , and the metal layer  134  from the inner side of the ink accommodating container  100 . The first base layer  131  and the second base layer  133  are served as base of the flexible material and, for example, the first base layer  131  is made of linear low density polyethylene and the second base layer  133  is made of low density polyethylene. In this case, since the flexible material has flexibility, the side face  102  and the side face  103  are easily folded. The gas barrier layer  132  prevents air from transmitting the ink accommodating container  100  and also prevents air from solving into the ink. For example, the gas barrier layer  132  is made of ethylene-vinyl alcohol copolymer, which is sandwiched between the first base layer  131  and the second base layer  133  thereby to be held between them. The metal layer  134  prevents the solvent of the ink from transmitting the ink accommodating container  100 . The metal layer  134  is, for example, an aluminum layer, which is formed on the second base layer  133  by vapor deposition. 
     FIG. 6A  is a sectional view of the ink accommodating container  100  in a longitudinal direction when the ink accommodating container  100  is filled with ink. When the ink accommodating container  100  is filled with the ink, the side face  102 , the side face  103 , the upper face  104  and the rear edge face  105  are not folded. While the front edge face  101  is fixed to the resin case  20  via the supplying part  120 , the rear edge face  105 , which is opposite to the front edge face  101 , is not fixed to the resin case  20 , so that the rear edge face  105  is allowed to move in the resin case  20 . 
     FIG. 6B  is a sectional view of the ink accommodating container  100  in a longitudinal direction when the ink in the ink accommodating container  100  has run out.  FIG. 7  is a perspective view of the ink accommodating container  100  when the ink in the ink accommodating container  100  has run out. As described above, the side face  102 , the side face  103 , the upper face  104  and the bottom face  106  are folded into the inside of the ink accommodating container  100  when the ink accommodating container  100  is substantially empty. Here, the front edge face  101  is fixed to the resin case  20  and the rear edge face  105  is allowed to move in the resin case  20 . Accordingly, the rear edge face  105  approaches to the front edge face  101  as the ink is consumed from the ink accommodating container  100  and then the side face  102  and the side face  103  are folded. Moreover, the upper face  104  and the bottom face  106  are in contact with each other and an end part of the upper face  104  near the front edge face  101  is folded along the assist fold line  116  to contact with the front edge face  101  and another end part of the bottom face  106  near the rear edge face  105  is also folded along the assist fold line  116  to contact with the rear edge face  105 . Thus, there is little space in the ink accommodating container  100  when the ink in the ink accommodating container  100  has run out. Therefore, the front edge face  101  and ink accommodating container  100  can supply almost all ink therein. 
     FIG. 8  is a perspective view of the die  200  which is used when the ink accommodating container  100  is manufactured by the direct blow molding method.  FIG. 9  is a plan view of die  220  included in the die  200 .  FIG. 10  is an A-A sectional view of the die  220  in  FIG. 9 . As shown in  FIG. 8 , the die  200  includes a die  220  and a die  240 . A concave part of the inner face of the die  220  and a concave part of the inner face of the die  240  are plane symmetry each other. Each of these concave parts includes a shape which is produced from the ink accommodating container  100  that is divided by a plane including the middle fold line  114  of the side face  102  and the middle fold line  114  of the side face  102  as shown in  FIG. 3 . The die  220  includes a die side face  202  for forming both the side face  102  and the side face  103  of the ink accommodating container  100 , a die upper face  204  for forming the upper face  104 , a die front edge face  208  for forming the front edge face  101 , and a die rear edge face  209  for forming the rear edge face  105 . In addition, the die upper face  204  of the die  240  forms the bottom face  106 . 
   As shown in  FIG. 8 , each of the die front edge face  208  and the die rear edge face  209  is rectangular, and they forms both of the front edge face  101  and the rear edge face  105  of the ink accommodating container  100  as shown in  FIG. 2  when the die  220  and die  240  are sandwiched each other. 
   In addition, the die front edge face  208  includes a blowing jig insertion opening  206 . The blowing jig is inserted into this blowing jig insertion opening  206 , thereby the supplying part  120  of the ink accommodating container  100  is formed between the blowing jig insertion opening  206  and the blowing jig. The blowing jig insertion opening  206  has a root part forming part  206   a  which forms the outside of the root part  122  of the supplying part  120  and a tip part forming part  206   b  which forms the outside of the tip part  124  of the supplying part  120 . The shape of the cross-section of the root part forming part  206   a  is semicircular and the root part forming part  206   a  connects the concave part of the die  200  and the tip part forming part  206   b . The shape of the cross-section of the tip part forming part  206   b  is also semicircular and the tip part forming part  206   b  is connected to the outer face of the die  200 . The inside diameter of the root part forming part  206   a  is little smaller than that of the opening  42  of the upper cover  40  shown in  FIG. 2 . Therefore, in the supplying part  120  of the ink accommodating container  100 , the root part  122  is formed so that the outside diameter of the root part  122  becomes smaller than the inside diameter of the opening  42 , and the tip part  124  is formed so that the outside diameter of the tip part  124  becomes larger than the inside diameter of the opening  42 . 
   As shown in  FIGS. 8 and 9 , the die upper face  204  has two convex parts  204   a , which are formed to be linear. One convex part  204   a  is formed on a vicinity of the die front edge face  208  in parallel with the die front edge face  208  and the other convex part  204   a  is formed on a vicinity of the die rear edge face  209  in parallel with the die rear edge face  209 , thereby they form the assist fold lines  116  of the ink accommodating container  100 . 
   Each of the two die side faces  202  on the concave part of the die  220  forms the side face  102  or the side face  103  respectively when the die  220  and the die  240  are sandwiched together. As shown in  FIGS. 8 and 10 , the die side face  202  slightly slopes to the inside of the die  220  and projects to the inside of the die  220 . The die side face  202  has a triangular cutout face  210  at a boundary between the die side face  202  and the die front edge face  208  in order to form the die front edge face  208  to be rectangular and also has another triangular cutout face  210  at a boundary between the die side face  202  and the die rear edge face  209  in order to form the die rear edge face  209  to be rectangular. In addition, the die side face  202  has a middle fold line forming part  202   a  and a diagonal fold line forming part  202   b . The middle fold line forming part  202   a  is a linear convex part which forms the boundary between the die side face  202  and the inner face of the die  220  and the middle fold line forming part  202   a  forms the middle fold line  114  when the die  220  and the die  240  are sandwiched. The diagonal fold line forming part  202   b  is a liner and acute-angled convex part which forms the boundary between the cutout face  210  and the die side face  202 , and the diagonal fold line forming part  202   b  forms the diagonal fold lines  112 . 
     FIG. 11  is a sectional view of the die  200  into which the blowing jig  300  and the parison  400  are inserted.  FIG. 12  is an enlarged view of the area surrounded by broken line in  FIG. 11 . In  FIG. 11 , the die  220  is shown as the B-B sectional view in  FIG. 2 . As shown in  FIG. 11 , the blowing jig  300  for blowing air includes a tip part  302  and a root part  304  and the tip part  302  is formed so that the diameter of the tip part  302  is smaller than that of the root part  304 . 
   In the case of molding the ink accommodating container  100 , at first, the die  220  and the die  240  are separated from each other and the cylindrical parison  400  is located between the die  220  and the die  240 . Next, the die  220  and the die  240  are combined together so that the parison  400  is sandwiched between the die  220  and the die  240 . The outside diameter of the parison  400  is larger than the diameter of the blowing jig insertion opening  206  and the parison  400  includes the first base layer  131 , the gas barrier layer  132 , and the second base layer  133  in the order of the first base layer  131 , the gas barrier layer  132 , and the second base layer  133 , from the inner side. The wall thickness of the parison  400  is thicker than the space between the blowing jig insertion opening  206  and the blowing jig  300  when the die  220  and the die  240  are combined together. 
   Next, the blowing jig  300  is inserted into the parison  400  so that the boundary between the tip part  302  and the root part  304  faces to the boundary between the root part forming part  206   a  and the tip part forming part  206   b . Here, the cross-section area of each of the blowing jig insertion opening  206  and the blowing jig  300  is smaller than that of the parison  400 . Thus, a section in the parison  400  is sandwiched between the blowing jig insertion opening  206  and the blowing jig  300 , and consequently a part of the section is deformed along the shape of the space between the die  200  and the blowing jig  300 . Therefore the part is molded to be smaller than the outside diameter of the parison  400  and thereby forms the supplying part  120  of the ink accommodating container  100 . In this case, since the inside diameter of the tip part forming part  206   b  of the die  200  is larger than that of the root part forming part  206   a , the outside diameter of the tip part  124  becomes larger than that of the root part  122 . In addition, since the outside diameter of the root part  304  of the blowing jig  300  is larger than that of the tip part  302 , the inside diameter of the tip part  124  becomes larger than that that of the root part  122 . 
   Next, when air is blown from the blowing jig  300 , the parison  400  protrudes and deforms along the shape of the concave part of the die  200  to form the ink accommodating container  100 . In this case, the diagonal fold line  112  are formed by the diagonal fold line forming part  202   b  on both the side face  102  and the side face  103  of the ink accommodating container  100  and, the middle fold line  114  are formed by the resin case  202   a . In addition, the assist fold line  116  is formed by the convex part  204   a  on both the side face  102  and the side face  103  of the ink accommodating container  100 . Since the protrusion of each part corresponding to the front edge face  101  or the rear edge face  105  in the parison  400  is not very large, the thickness of each of the front edge face  101  and the rear edge face  105  is formed to be thicker than that of the side face  102 , the side face  103 , the upper face  104  or the rear edge face  105 . Next, the metal layer  134  is vapor deposited to the outer surface of the ink accommodating container  100 . 
   According to the present embodiment as described above, since the diagonal fold line  112  and the middle fold line  114  are formed on each of the side face  102  and the side face  103  of the ink accommodating container  100 , both the side face  102  and the side face  103  are folded as the ink is being supplied from the ink accommodating container  100 . Therefore, the amount of the ink left in the used ink accommodating container  100  is can be reduced. In addition, since the assist fold line  116  is formed on each of the upper face  104  and the bottom face  106 , both the upper face  104  and the bottom face  106  are folded along the front edge face  101  and the rear edge face  105 . Therefore, though both the front edge face  101  and the rear edge face  105  are not easily folded because they are formed to be thicker than the others faces, the amount of the ink left in the used ink accommodating container  100  can be reduced. 
   In addition, when using the direct blow molding method, though the outside diameter of the supplying part  120  of the ink accommodating container  100  is smaller than that of the parison  400 , the supplying part  120  can be formed in the space between the blowing jig  300  and blowing jig insertion opening  206 , into which the blowing jig  300  is inserted. Here, since the inside diameter of the tip part forming part  206   b  of the blowing jig insertion opening  206  is smaller than that of the root part forming part  206   a , the outside of the tip part  124  of the supplying part  120  can be formed to be larger than the inside diameter of the root part  122 . In addition, since the diameter of tip part  302  of the blowing jig  300  is smaller than the other parts, the inside diameter of the tip part  124  can be larger than that of the root part  122 . 
   In addition, the ink-jet recording apparatus used with ink cartridge  10  is an example of the liquid ejecting apparatus. However, the present invention is not limited to this. A color filter manufacturing apparatus for manufacturing a color filter of a liquid crystal display could be another example of the liquid ejecting apparatus. In this case, a color material ejecting head of the color filter manufacturing apparatus is an example of the liquid ejecting head. Yet another example of the liquid ejecting apparatus is an electrode forming apparatus for forming electrodes such as an organic EL display, an FED (Field Emission Display) or the like. In this case, an electrode material (conductive on paste) ejecting head of the electrode forming apparatus is an example of the liquid ejecting head. Yet another example is a biochip manufacturing apparatus for manufacturing biochips. In this case, the cartridge of a biochip manufacture apparatus which holds organic substance and samples is an example of a liquid cartridge. The liquid ejecting apparatus of the present invention includes other liquid ejecting apparatuses used for industrial purposes. In addition, the recording medium is a material on which recording or printing is performed by ejection of liquid, which includes a recording paper, a circuit board on which circuit patterns such as display electrodes are formed, a CD-ROM on which a label is printed, a prepared slide on which a DNA circuit is recorded, etc. 
   Although the present invention has been described by way of exemplary embodiments, it should be understood that those skilled in the art might make many changes and substitutions without departing from the spirit and the scope of the present invention which is defined only by the appended claims.