JP4848208B2 - Method for manufacturing parallel tube assembly - Google Patents

Description

  The present invention relates to a method of manufacturing a parallel tube assembly in which tubes are arranged in parallel and integrated, and more particularly to a method of manufacturing a parallel tube assembly in which tubes that are hard to clog ink are arranged.

In a large-sized inkjet printer for business use, ink is supplied from an ink tank to an inkjet head using an ink tube. Even when printing is stopped, ink remains in the ink tube, and if the solvent or moisture evaporates from the ink, the ink concentration becomes high, the viscosity becomes high, and clogging of the ink may occur. . Therefore, the ink tube is required to have a gas barrier property or a water vapor barrier property. Further, it is required that the ink tube does not stain the ink tube, that is, coloring resistance is also required. Furthermore, it is also required that the rigidity is small so as not to resist the movement of the inkjet head during printing. In view of this, an ink tube has been proposed in which polyethylene is used for the material of the inner layer and the outer layer, and an ethylene vinyl alcohol copolymer or polyvinylidene chloride is used for the intermediate layer (see Patent Document 1).
JP-A-9-300652 (page 3, FIG. 1)

  However, a color inkjet printer includes an ink tank, an inkjet head, and an ink tube for each color, and a plurality of ink tubes move differently in the printer. If multiple ink tubes move differently, the ink tubes may rub against each other, damaging the surface, or the ink tubes may become entangled and restrain the movement, resulting in great resistance to the movement of the inkjet head. is there. Therefore, it is required to combine a plurality of tubes into one. However, if an adhesive or the like is used to combine the tubes, there is a problem that the rigidity of the ink tube increases and resistance to movement of the inkjet head increases. If the ink tube is deformed, the ink tube may be bent as a whole (also referred to as curl), or the cross section of the ink tube may be deformed to an extent that affects the flow of ink. Is concerned. Accordingly, an object of the present invention is to provide a method for manufacturing a parallel tube assembly in which tubes are arranged in parallel and integrated with less initial deformation of the tube.

In order to achieve the above object, a method of manufacturing a parallel tube assembly according to a first aspect includes a step of arranging at least two tubes 10 made of a polymer material in parallel as shown in FIGS. 1 and 6, for example. (Step S20); and a step (Step S30) in which hot air is blown locally to the place where the tubes 10 arranged in parallel contact with each other and locally heated to thermally weld the tubes 10 together.

  If comprised in this way, since hot air is blown to the location where tubes mutually contact and it heats locally and tubes are heat-welded, the location which receives the influence of the heating in the case of heat welding becomes small. Therefore, heat welding can be performed while suppressing deformation of the cross section of the tube.

Moreover, the manufacturing method of the parallel tube assembly of a 2nd aspect is a heating method of the tube 10 heat-welded in the manufacturing method of the parallel tube assembly of a 1st aspect , for example, as shown in FIG.1 and FIG.6. And heat fixing (step S40).

  If comprised in this way, since heat setting is performed after heat welding, the deformation | transformation of a subsequent parallel tube assembly can be restrained small.

Moreover, the manufacturing method of the parallel tube assembly of a 3rd aspect is the manufacturing method of the parallel tube assembly of a 1st aspect or a 2nd aspect , for example, as shown in FIG. 1 and FIG. 30 and includes a step of feeding the tube 10 out of the bobbin 30 (step S10).

  If comprised in this way, a tube can be manufactured beforehand by winding a tube around a bobbin, and a parallel tube aggregate can be manufactured from a tube without deformation, such as bending, wound around a bobbin. Moreover, since the tube can be wound around the bobbin, it is easy to transport and store the tube.

Moreover, the manufacturing method of the parallel tube assembly of a 4th aspect is a manufacturing method of the parallel tube assembly of any one of a 1st aspect thru | or a 3rd aspect , for example, as shown in FIG. The step of welding is performed while the opening 55 moves relative to the tube 10 in the longitudinal direction of the tube 10, and the step of heat welding while the opening 55 moves relative to the tube 10. Is stopped.

  If comprised in this way, the parallel tube assembly provided with the part by which the tubes arranged in parallel were heat-welded and the part which is not heat-welded can be manufactured. Thus, for example, at the end where each tube is connected to a nozzle at a different position, the tubes are not thermally welded to each other, and the other portion is a parallel tube assembly in which the tubes are thermally welded as one unit. Become.

Moreover, the manufacturing method of the parallel tube assembly of a 5th aspect is the tube manufacturing method of the parallel tube assembly of any one of a 1st aspect thru | or a 4th aspect , for example, as shown in FIG. 10 has two layers of an inner layer 10a and an outer layer 10e disposed outside the inner layer 10a, and the polymer material of the inner layer 10a is formed of a material having a crystal melting temperature higher than that of the polymer material of the outer layer 10e.

  When configured in this way, even if hot air is blown at a temperature at which the outer layer is thermally welded, the inner layer retains its cross-sectional shape without melting, so deformation of the inner layer cross section due to heat during heat welding can be suppressed, It does not affect the flow of fluid flowing through the tube.

In addition, as shown in FIG. 2, for example, in the method of manufacturing the parallel tube assembly of the fifth aspect , the polymer material of the outer layer 10e is an ethylene / α-olefin. It is a copolymer, and the polymer material of the inner layer 10a is polyethylene.

  With this configuration, the inner layer polyethylene has a higher crystal melting temperature, and the outer layer ethylene / α-olefin copolymer has a lower crystal melting temperature and is softer than polyethylene. Even if hot air is blown at a temperature at which heat welding is performed, the shape of the polyethylene is maintained without melting and deformation of the tube cross section due to heat welding can be suppressed, and the flow of fluid flowing through the tube is not affected. Moreover, since the ethylene / α-olefin copolymer of the outer layer is soft, the parallel tube assembly is easy to bend, and even when bent, it is difficult to produce kinks.

Moreover, the manufacturing method of the parallel tube assembly according to the seventh aspect is, for example, as shown in FIG. 2, in the manufacturing method of the parallel tube assembly according to the fifth aspect or the sixth aspect , the tube 10 is connected to the outer layer 10 e. This is a multilayer tube having an intermediate layer 10c of an ethylene / vinyl alcohol copolymer between the inner layer 10a.

  If comprised in this way, since it has the intermediate | middle layer of an ethylene vinyl alcohol copolymer, water vapor | steam and gas are very difficult to permeate | transmit, and can prevent the evaporation of the fluid which flows through a tube, or the penetration | invasion of outside air into a tube.

  According to the method for manufacturing a parallel tube assembly according to the present invention, at least two tubes formed of a polymer material are arranged in parallel, and hot air is blown locally to the place where the tubes arranged in parallel contact each other. Therefore, it is possible to reduce the portion affected by the heating during the heat welding. Therefore, heat welding can be performed while suppressing deformation of the cross section of the tube.

  Embodiments of the present invention will be described below with reference to the drawings. In each figure, the same or equivalent devices are denoted by the same reference numerals, and redundant description is omitted.

  1A and 1B are schematic diagrams for explaining a method of manufacturing a parallel tube assembly 20 used in a business inkjet printer, which is an embodiment of the present invention. FIG. 1A is an overall view, and FIG. It is a bb arrow line view. In FIG. 1A, the manufacturing process flows from the left side to the right side and is processed. The tube 10 is wound around the bobbin 30 prior to the production. In the manufacture of the parallel tube assembly 20, the tube 10 is manufactured separately and wound around the bobbin 30, so that the parallel tube assembly 20 can be manufactured separately from the manufacture of the tube 10, so the degree of freedom increases. The production rate of the parallel tube assembly 20 is not affected by the production rate of the tube 10. By winding the tube 10 around the bobbin 30, it is possible to prevent the tube from being bent and to facilitate transportation and storage. However, the tube 10 may not be wound around the bobbin 30, and the tube may be manufactured at the same time as the parallel tube assembly is manufactured.

  Here, with reference to FIG. 2, the typical example of the tube used for manufacture of the parallel tube assembly 20 is demonstrated. FIG. 2 is a cross-sectional view of a tube used for manufacturing the parallel tube assembly 20, in which (a) shows a tube 10 having an intermediate layer in addition to an inner layer and an outer layer, and (b) shows a tube 12 having an inner layer and an outer layer. It is sectional drawing.

  2A includes an inner layer 10a, an intermediate layer 10c, and an outer layer 10e, and an adhesive layer 10b is bonded between the inner layer 10a and the intermediate layer 10c, and an adhesive is bonded between the intermediate layer 10c and the outer layer 10e. It has a layer 10d. The outer layer 10e is a layer that is heat-welded when the tubes 10 are heat-welded to form the parallel tube assembly 20, and the other layer 10a is formed so as to be easily heat-welded and due to a temperature rise during heat-welding. It is preferable to be formed of a polymer material having a crystal melting temperature lower than that of the other layers 10a to 10d so that 10 to 10d is not melted or greatly softened and deformed. Here, the crystal melting temperature is typically specified by using a peak temperature by a differential scanning calorimetry (DSC) method of JIS; K7121 (measurement method of plastic transition temperature). Further, since the outer layer 10e is the portion that generates the largest strain when the tube 10 is bent and deformed, the outer layer 10e is preferably formed of a soft polymer material. Therefore, an ethylene / α-olefin copolymer is preferably used in a parallel tube assembly for ink tubes used in a commercial inkjet printer. The ethylene / α-olefin copolymer has a crystal melting temperature of about 94 ° C., a crystal melting temperature of polyethylene described later of about 121 ° C., a crystal melting temperature of ethylene / vinyl alcohol copolymer of about 172 ° C., or low density polyethylene (LDPE). ) The crystal melting temperature of the adhesive is lower than about 112 ° C. and is soft. In addition, since the ethylene / α-olefin copolymer has a high water vapor barrier property and gas barrier property, from the viewpoint of preventing evaporation of moisture, solvent, etc. from the contents of the tube 10 or mixing of air into the contents. Is also preferable. Here, the polymer material is a thermoplastic resin, and refers to a resin that can be melted, welded, thermally deformed, and crystallized by a known heating means.

  The inner layer 10a is a layer that is in direct contact with the fluid flowing through the tube 10, and is preferably formed of a polymer material that is not altered by the fluid. In the parallel tube assembly for the ink tubes used in the business inkjet printer, polyethylene is preferably used. When polyethylene is used for the inner layer 10a, it is not colored by ink, and since it has a high water vapor barrier property and gas barrier property, evaporation of moisture, solvent, etc. from the contents of the tube 10, or air to the contents It is also preferable from the viewpoint of preventing mixing.

  The intermediate layer 10c is a layer provided to be a water vapor barrier layer or a gas barrier layer. Therefore, it is formed of a polymer material having extremely high water vapor barrier properties or gas barrier properties. For example, an ethylene / vinyl alcohol copolymer is preferably used. The ethylene / vinyl alcohol copolymer has a hydroxyl group and is a highly reactive polymer material. However, since it is sandwiched between the inner layer 10a and the outer layer 10e, the ethylene / vinyl alcohol copolymer does not come into contact with the reacting substance, and depends on the reaction. There will be no alteration.

  The adhesive layers 10b and 10d are layers that are interposed between the inner layer 10a and the intermediate layer 10c, and between the intermediate layer 10c and the outer layer 10e, and adhere the inner layer 10a, the intermediate layer 10c, the intermediate layer 10c, and the outer layer 10e. Since it is a layer for bonding, the bonding layers 10b and 10d are formed thin. The adhesive layers 10b and 10d are typically formed of an LDPE adhesive that is easily available. Thus, by forming a multi-layer tube of 3 layers (5 layers including the adhesive layer), the tube 10 has excellent heat welding property, flexibility, color resistance, extremely high gas barrier property or water vapor barrier property. . In addition, a multilayer tube means the tube of 2 or more layers which is not a single layer, and points out the tube of 3 layers or more especially.

  When a high gas barrier property or water vapor barrier property is not required, as shown in FIG. 2 (b), it has an inner layer 12a and an outer layer 12c, and an adhesive layer 12b is provided between the inner layer 12a and the outer layer 12c. You may manufacture the parallel tube assembly 20 using the tube 12 which has. The tube 12 has the same configuration as that in which the intermediate layer 10c is omitted from the tube 10. Since the ethylene / vinyl alcohol copolymer suitably used as the intermediate layer 10c is a relatively expensive material, it is omitted. By using the tube 12, the parallel tube assembly 20 can be manufactured at low cost. In the tube 12 for manufacturing the parallel tube assembly 20 for the ink tube used for a typical commercial inkjet printer, the outer diameter is 4 mm, the outer layer 12 c is 0.25 mm, the adhesive layer 12 b is 0.03 mm, and the inner layer 12 a is The thickness is 0.12 mm. You may manufacture the parallel tube assembly 20 using another tube according to a use etc.

  Returning to FIG. 1A, the description of the method for manufacturing the parallel tube assembly 20 will be continued. The six tubes 10 fed out from the bobbin 30 are guided by the guide roller 32 and aligned in parallel on the grooved plate 40. The guide roller 32 changes the feeding direction of the tube 10 fed from the bobbin 30 to the grooved plate 40 and adjusts the tension of the tube 10 generated by the feeding, so that the plurality of tubes 10 are moved on the grooved plate 40. Make sure they are parallel to each other without bending. The tension of the tube 10 is adjusted by adjusting the magnitude of changing the direction of the tube 10 with the guide roller 32, that is, by shifting the position of the guide roller 32. Although only one guide roller 32 is shown for each tube 10 in FIG. 1, a plurality of guide rollers 32 may be provided for each tube 10.

  As shown in FIG. 1B, the grooved plate 40 has a groove 44 on which each tube 10 moves, and the grooves 44 are arranged close to each other so that the tubes 10 come into contact with each other. . In FIG. 1, six tubes 10 are integrated in parallel, and the grooved plate 40 is also shown as having six grooves 44 formed. However, the number of grooves 44 is the same as that of the tube 10. Any number may be used as long as it is more than the number. Further, the number of tubes 10 is not limited to six, and the number is increased or decreased depending on the application. In addition, the groove 44 approaches so that the tubes 10 may come into contact with each other when the tubes 10 are heat-welded, and on the upstream side, the beam nozzle 50 (for blowing hot air between the heat-welded tubes 10 ( 50A, 50B, and 50C are collectively referred to as 50.) are spaced so as to secure a space for arranging them. A cooling medium C is introduced into the grooved plate 40 to cool the surface of the groove 44. For example, the surface of the groove 44 is cooled to a low temperature of 5 to 10 ° C. Since the grooved plate 40 is cooled, as will be described later, even if the tube 10 is blown with hot air, the temperature of the tube 10 that travels on the grooved plate 40 is prevented from rising. Therefore, the surface of the tube 10 is prevented from being softened due to a temperature rise, and an increase in frictional resistance is avoided. As the cooling medium C, cooling water is typically used, and the cooling water flow path 42 is disposed in the grooved plate 40 near the groove 44.

  In addition, you may align the tube 10 using a grooved roller (not shown) instead of the grooved plate 40. FIG. The grooved roller is a roller having a surface formed with parallel grooves similar to the grooved plate 40, and the grooved roller rotates so that the groove moves at the same speed as the tube 10 to be fed. As described above, when the tube 10 is aligned on the grooved roller that moves at the same speed as the tube 10, the frictional resistance generated between the tube 10 and the groove does not matter, so the surface of the groove is cooled with a cooling medium. It does not have to be. However, if the grooved plate 40 is used, the tube 10 can be supported by a continuous surface, so that deformation that occurs in the tube 10 can be suppressed and the tube 10 can be prevented from vibrating. Further, the configuration is simplified without controlling the groove to move at the same speed as the tube 10 is fed.

  Hot air A is blown from the beam nozzle 50 to the contact portion (also referred to as a joint portion) of the tubes 10 at a position where the tubes 10 arranged in parallel on the grooved plate 40 start to contact each other. By blowing hot air A, for example, when the outer layer 10e (see FIG. 2) is formed of an ethylene / α-olefin copolymer having a crystal melting temperature of about 94 ° C., the joint is heated to about 100 ° C. , Heat weld.

  Here, the beam nozzle 50 that blows the hot air A will be described with reference to FIG. 3A and 3B are perspective views for explaining the configuration of the beam nozzle. FIG. 3A is a beam nozzle 50A (50B) including a nozzle body 52 and a nozzle tip 54, and FIG. 3B is an on-off valve for letting hot air A escape to the nozzle body 52. Beam nozzles 56 and 57 (c) including 57 indicate beam nozzles 58 in which the direction of the nozzle tip 59 is variable. First, the beam nozzle 50A shown in FIG. The beam nozzle 50A includes a cylindrical nozzle body 52 that is thicker or substantially the same diameter as a pipe connected to a pipe (not shown) for supplying high-temperature air, and an end face of the nozzle body 52 opposite to the end face connected to the pipe. And a nozzle tip 54 that is a thin-diameter nozzle protruding from the nozzle.

  The opening 55 at the opening end of the nozzle tip 54 is generally formed smaller than the tube 10 to be thermally welded. The opening 55 being smaller than the tube 10 means that the length (width) of the opening 55 in the direction in which the tubes 10 are arranged in parallel is smaller than the width in the direction in which the tubes 10 are arranged in parallel. Thus, since the width | variety of the opening part 55 is smaller than the width | variety of the tube 10, the hot air A blown out from the opening part heats only the junction part to which the tube 10 contacts and heat-welds locally. Here, “locally heating” refers to heating so that only the part to be thermally welded is melted, but may include the case where the vicinity of the part to be thermally welded is melted. The vicinity of the part to be heat-welded is not deformed as a whole in the cross section of the tube 10 even if the range melts, such as a range of 1/10 or less of the outer periphery of the tube 10 from the place to be welded, A range that does not deform so much as to affect the flow of fluid inside. Since the range in which the tube 10 is heated is limited to the joint or the vicinity thereof, the entire cross section of the tube 10 is not heated and deformed, and deformation of the cross section can be suppressed. In the case of a circular cross section, it is easy to maintain the roundness of the tube 10. Further, an increase in friction with the grooved plate 40 due to softening of the outer layer 10e (see FIG. 2) of the tube 10 can be prevented, and in addition, since hot air is blown only on the portion where heat welding is performed, there is no waste and efficiency is increased. In addition, since the hot air A which blows off from the opening part 55 reaches | attains the junction part of the tube 10, enclosing surrounding air, the flow of the hot air A becomes thick in the meantime. Accordingly, although the width varies depending on the distance between the opening 55 and the joint portion of the tube 10, the width of the opening 55 is preferably less than or equal to ½ of the width of the tube 10, and more preferably less than or equal to ¼. And Thus, by forming the width of the opening 55 small, the flow of the hot air A blown to the joint portion of the tube 10 becomes thin, and the joint portion can be locally heated.

  For example, when the above-mentioned outer layer having an outer diameter of 4 mm is formed of an ethylene / α-olefin copolymer and is thermally welded to a tube that is moving relative to the beam nozzle at a speed of 2 m / min, 0. A beam nozzle having a circular opening with an inner diameter of 5 mm is used. Hot air at a temperature of 190 ° C. and a pressure of 9.5 Pa (G) is supplied to the beam nozzle, and the opening is separated from the joint of the tube by 1 mm, and hot air is blown. As a result, the joint is heated to about 100 ° C.

  The beam nozzle 50 </ b> A includes two nozzle tips 54. As described above, by providing a plurality of nozzle tips 54, it is possible to perform heat welding at a plurality of locations at the same time, thereby increasing the efficiency. However, if a large number of nozzle tips 54 are provided and hot air is blown simultaneously from a large number of openings 55, the hot air is filled around the tube 10 and the entire tube 10 may be heated. Therefore, it is preferable to set the number of nozzle tips 54 to, for example, 2 or less and 3 or less without increasing the number of nozzle tips 54 so much. Note that the number of nozzle tips may be one as in the case of the beam nozzle 50C (see FIG. 1).

  What is necessary is just to stop the spraying of the hot air A to the tube 10 when stopping heat welding. However, when the blowing of hot air A is started, the temperature of the pipe (not shown), the nozzle body 52, and the nozzle tip 54 itself is lowered, and the temperature is lowered to the pipe, the nozzle body 52, and the nozzle tip 54. If the remaining air remains, a transition period until hot air A having a predetermined temperature is blown out occurs. Even if hot air A having a predetermined temperature or less is blown in the transition period, the tube 10 is not thermally welded, but deformation due to heat may occur. Therefore, it is not preferable that the transition period occurs. Further, if hot air A is continuously blown for a long time until hot air A rises to a predetermined temperature, the wide range of tube 10 becomes high temperature, which is not preferable. Therefore, when the thermal welding is stopped, the hot air A is kept from being blown from the beam nozzle 50 so that the hot air A is not applied to the tube 10. Typically, the beam nozzle 50 is separated from the joint portion of the tube 10, and when the thermal welding is started, the beam nozzle 50 blowing hot air A is brought close to the joint portion of the tube 10.

  Alternatively, as shown in FIG. 3B, when the short pipe with the opening / closing valve 57 is branched from the nozzle body 52 of the beam nozzle 56 and the thermal welding is stopped, the opening / closing valve 57 is opened and supplied to the beam nozzle 56. High temperature air may be discharged from the short tube. By making the cross section of the short tube sufficiently larger than the cross section of the nozzle tip 54, most of the high-temperature air supplied to the beam nozzle 56 can be discharged from the short tube due to the difference in fluid resistance. Then, only a small amount of hot air is discharged from the opening 55, and the tube 10 is not heated to a high temperature. Moreover, when starting heat welding, the on-off valve 57 is closed. At this time, air remains in the nozzle tip 54 and part of the nozzle body 52, but the amount of residual air is very small and high-temperature air flows through the nozzle body 52, so that the nozzle body 52 The nozzle tip 54 itself is heated to a high temperature, and the temperature of the remaining air is maintained high. Therefore, the transition period until the hot air A of a predetermined temperature blows out becomes short enough to be ignored.

  Further, as shown in FIG. 3C, the direction of the nozzle tip 59 is variable, the opening 55 is directed away from the joint portion of the tube 10 when the thermal welding is stopped, and the opening is opened when the thermal welding is started. The portion 55 may be directed toward the tube 10. In order to change the direction of the nozzle tip 59, the nozzle tip 59 itself may be deformed, but the nozzle tip 59 may be connected to the end surface of the nozzle body 52 at an angle, and the end surface may be rotated. If only the end face is rotated to change the direction of the nozzle tip 59, the configuration becomes simple and the direction can be changed quickly. Therefore, the stop and start of heat welding can be switched quickly.

  If the thermal welding is stopped and started by moving the beam nozzle 50, the configuration of the beam nozzle 50 is easy, and the opening 55 is separated so that the tube 10 is not affected by the hot air A. Can be. Further, when the thermal welding is stopped and started by opening and closing the on-off valve 57 as in the beam nozzle 56, the movable portion can be made small, leading to a reduction in mechanical failure. In addition, when the thermal welding is stopped and started by changing the direction of the nozzle tip 59 like the beam nozzle 58, the thermal welding can be quickly stopped and started.

  Returning to FIG. 1, the description of the method for manufacturing the parallel tube assembly will be continued. In order to make the six tubes 10 into the parallel tube assembly 20, three beam nozzles 50 are used. This is because three tubes are thermally welded together by a beam nozzle 50A having two nozzle tips 54 (see FIG. 3), and another tube nozzle 50B having another two nozzle tips 54 is used for another. Three tubes are heat-welded and combined into one, and the three tubes combined are heat-welded with a beam nozzle 50C having one nozzle tip 54 to form one parallel tube assembly. It is. In addition, the method of carrying out the heat welding of the tube 10 and putting together sequentially is not restricted above. The beam nozzles 50 </ b> A and 50 </ b> B have two nozzle tips 54, and in order to collect six tubes, the above method requires fewer heat weldings, that is, fewer beam nozzles 50 are used. Further, the beam nozzles 50A, 50B, and 50C are arranged at different positions in the moving direction of the tube 10, that is, the longitudinal direction of the tube 10. By arranging the beam nozzles 50A, 50B, and 50C at different positions in this way, the hot air A blown from the beam nozzles 50A, 50B, and 50C is prevented from being filled in a narrow range, and the heat of the tube 10 is increased. It is prevented that locations other than the locations to be welded are heated to such a high temperature that they are deformed by the hot air A. However, the beam nozzles 50 </ b> A, 50 </ b> B, and 50 </ b> C may be disposed at the same position in the longitudinal direction of the tube 10.

  The heat-welded tube 10 is subsequently bathed with hot water H sprayed from the hot water spray port 60 and heated. Or you may immerse and heat in the tank (not shown) which stores a hot water. The temperature to be heated is lower than any of the crystal melting temperatures of the polymer material constituting the tube 10 and higher than any of the softening point temperatures. Thus, by heating to a temperature lower than the crystal melting temperature and higher than the softening point temperature, the molecular orientation of the polymer material forming the tube 10 is unraveled, the crystallinity is increased, and the shape is increased. Is stabilized. Heating in this way to adjust the molecular orientation and increase the crystallinity is called heat setting. The temperature for heat setting may be equal to or higher than the softening point, but the time required for heat setting to a desired level depends on the temperature, and becomes shorter as the temperature is higher. Therefore, usually, the temperature is heated to a temperature close to the crystal melting temperature and heat setting is performed in a short time.

  Heating for heat fixation may be performed by hot air or heat radiation instead of hot water H. When the hot water H is used, the heat capacity of water is large, so that the six tubes 10 can be heated to a uniform temperature, temperature unevenness can be reduced, and the heat can be fixed uniformly. Heat setting is an operation to increase the crystallinity of the polymer material to a predetermined level by heat treatment so that it is suitable for handling in the subsequent process. As a result, the dimensions of the formed polymer material change over time. Can be suppressed. That is, dimensional stability is improved. In the parallel tube assembly 20 using the tube 10 shown in FIG. 2 (a), if the heat setting is not performed, the maximum dimension is reduced by about 10% compared to the dimension immediately after the molding. Compared to the dimension immediately after molding, it can be suppressed to a dimension reduction within about 5%, and depending on the method of heat setting, it can be suppressed to a dimension reduction within about 3%. As an operation for increasing the crystallinity to a predetermined level by heat treatment, for example, the parallel tube assembly 20 is immersed in a bath of hot water for a predetermined time, and the crystallinity can be increased to a predetermined level by uniform heating. By this heat setting, the crystallinity of the ethylene / α-olefin copolymer is increased to about 20%, and high dimensional stability can be obtained. Further, when hot air is used, hot air at a lower temperature can be easily produced than hot welding using hot air for heat welding, and heating of the heat source is sufficient only with air. In addition, since no water is used, there is no need for drying after heat setting. Further, when heat radiation is used, water is not used, so that there is no need for drying after heat setting, and heat setting can be started and stopped quickly and easily.

  The six heat-fixed tubes 10 are taken up by a pair of rollers 70 and sent downstream. The pair of rollers 70 sandwich the six tubes 10 that are heat-welded and fixed in parallel from the direction orthogonal to the surfaces arranged in parallel, that is, sandwich each tube 10 and rotate the roller 70. , Taken from the left direction of FIG. By pulling out the six tubes 10 heat-welded and fixed in parallel by the roller 70, the tube 10 before heat-welding is fed out from the bobbin 30. Since the tube 10 is fixed by heat and stabilized after the shape is stabilized, deformation of the cross section of the tube 10 can be suppressed. Moreover, the hot water H adhering to the outer surface of the tube 10 is removed especially by pinching the tube 10 using the roller 70 which formed the groove | channel according to the shape of the tube 10 located in parallel with the surface.

  The six tubes 10 heat-welded and fixed in parallel that are fed from the roller 70 are cut into a predetermined length by the cutter 80, and the parallel tube assembly 20 is manufactured. The hot water H injected from the hot water injection port 60 does not enter the inner surface of the tube 10 by being cut into a predetermined length by the cutter 80 after being fixed by heat.

  Next, with reference to FIG. 4, the manufacturing method of the parallel tube assembly which stops a heat welding process regularly is demonstrated. FIG. 4 is a diagram for explaining the relationship between the feeding (pickup) of the tube 10 and the thermal welding process. In the figure, the tube 10 is sent from left to right as indicated by an arrow T in the figure, and the heat setting step is omitted. That is, the tube 10 drawn on the right side of the beam nozzles 50A to 50C is a tube 10 that has been thermally welded. In the figure, the position indicated by (4) indicates the location of the tube 10 where the thermal welding is started, and before that (right side), the thermal welding is not performed, and the tube 10 is not welded and is separated. .

  Thermal welding is performed at positions (3), (2), and (1), and the six tubes 10 are combined into one. When stopping the thermal welding, the thermal welding at the beam nozzle 50A is first stopped at the position (1). The tube 10 continues to be fed even while the thermal welding at the beam nozzle 50 is stopped. That is, the beam nozzle 50 and the tube 10 continue to move relatively in the longitudinal direction of the tube 10. When the tube 10 at the position where the thermal welding is stopped at the position (1) reaches the position (2), the thermal welding at the beam nozzle 50B is stopped. Next, when the tube 10 at the location where the thermal welding is stopped reaches the position (3), the thermal welding at the beam nozzle 50C is stopped. That is, the beam nozzle 50A, the beam nozzle 50B, and the beam nozzle 50C stop heat welding at the same location on the tube 10. In addition, when starting the thermal welding, similarly to the above, the heat at the beam nozzle 50A, the beam nozzle 50B, and the beam nozzle 50C is provided with a time difference so that the thermal welding is started at the same location on the tube 10. Start welding. This time difference is the time obtained by dividing the distance between the beam nozzles by the feed speed of the tube 10. The stop and start of these thermal weldings are preferably controlled by a controller (not shown). The controller controls the stop and start of heat welding according to the feeding of the tube 10. The controller may also be configured to control the feeding of the tube 10, that is, the rotational speed of the roller 70 (see FIG. 1) and the operation of the cutter 80 (see FIG. 1). In addition, when each beam nozzle 50A, 50B, 50C is arrange | positioned in the same position in the longitudinal direction of the tube 10, it is sufficient to start or stop each beam nozzle 50A, 50B, 50C simultaneously, Control becomes easy.

  FIG. 5 shows a parallel tube assembly 22 manufactured by the method described above. FIG. 5 is a front view of the parallel tube assembly 22 having a tube non-joining portion 26 where the tube 10 is separated from both ends, and a tube joining portion 24 to which the tube 10 is thermally welded therebetween. In this way, by having the tube non-joining portions 26 at both ends, the parallel tube assembly 22 as a whole is integrated into one, preventing the rubbing and entanglement of the tubes 10, and the other party connecting each tube 10 is The parallel tube assembly 22 is easily connected even if they are separated from each other. In particular, when each ink-jet head moves relatively like an ink-jet printer, it can follow each ink-jet head with a small resistance and can be easily connected even if each ink bottle is separated. Since it becomes the parallel tube assembly 22, it is suitable.

  In FIG. 6, the manufacturing process of the parallel tube assembly 20 (refer FIG. 1) is shown collectively. FIG. 6 is a flowchart of the manufacturing process of the parallel tube assembly 20. First, the tubes (single tubes) 10 (see FIG. 1) are fed out from the six bobbins, respectively (step S10). The tension of the six tubes 10 is adjusted, and the tubes 10 are aligned in parallel (step S20). Hot air is blown to the places where the tubes 10 are in contact with each other, and the aligned tubes 10 are locally heated and thermally welded (step S30). Next, the heat-welded tube 10 is heated and heat-fixed (step S40). The heat-fixed tube 10 is taken out (step S50) and cut into a predetermined length (step S60). As described above, the parallel tube assembly 20 in which the deformation of the tube cross section is suppressed and curling is suppressed is manufactured.

  In the description so far, it has been described that the hot air is blown from the fixed beam nozzle while the tube is being sent (taken), but the tube of a predetermined length is fixed in parallel on the grooved plate and stopped. Alternatively, heat welding may be performed by blowing hot air from a beam nozzle moving along the tube. In this case, a so-called box motion is performed in which the beam nozzle is brought close to the tube and thermally welded, and then separated from the tube (grooved plate) to return the beam nozzle to a position where the heat welding is started. While the beam nozzle is moving away from the tube, the tube is replaced with one that has been heat-welded to one that will be heat-welded from now on.

It is a schematic diagram explaining the manufacturing method of the parallel tube assembly which is embodiment of this invention, (a) is a general view, (b) is a bb arrow line view in (a). It is sectional drawing of the tube used for manufacture of a parallel tube assembly, (a) is a tube which has an intermediate | middle layer in addition to an inner layer and an outer layer, (b) is sectional drawing of a tube provided with an inner layer and an outer layer. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view explaining the structure of a beam nozzle, (a) is a beam nozzle provided with a nozzle main body and a nozzle tip, (b) is a beam nozzle provided with the on-off valve which escapes a hot air to a nozzle main body, (c) is a nozzle tip. A beam nozzle having a variable direction is shown. It is a figure explaining the relationship between the feeding of a tube, and a heat welding process. It is a front view of the parallel tube aggregate | assembly from which the tube of the both ends was separated. It is a flowchart of the manufacturing process of a parallel tube assembly.

Explanation of symbols

10, 12 Tube 20, 22 Parallel tube assembly 24 Tube joint portion 26 Tube non-joint portion 30 Bobbin 32 Guide roller 40 Grooved plate 42 Cooling medium flow path 44 Grooves 50, 56, 58 Beam nozzle 52 Nozzle body 54 Nozzle tip 55 Opening 57 Opening / closing valve 59 Movable nozzle tip 60 Hot water injection port 70 Roller 80 Cutter A Hot air C Cooling medium H Hot water

Claims (8)

Arranging at least two tubes formed of a polymer material in parallel;
Spraying hot air locally on the place where the tubes arranged in parallel contact each other, and locally welding the tubes ;
A grooved plate having grooves that closely align the at least two tubes in contact with each other, and running on the grooved plate that prevents temperature rise of the tubes;
The heat welding step is performed while the tube is traveling in the traveling step;
A method for manufacturing a parallel tube assembly. Heating the heat-welded tube to a temperature lower than the crystal melting temperature of the polymer material and higher than the softening point temperature by bathing with hot water ;
The manufacturing method of the parallel tube assembly of Claim 1. Arranging at least two tubes formed of a polymer material in parallel;
The parallel ordered by blowing hot air at a location tube contact each other to heat locally, e Bei a step of the tube between heat sealing;
The heat welding step is performed while the opening at the tip of the nozzle that blows out the hot air to be blown moves relative to the tube in the longitudinal direction of the tube, and the opening moves relative to the tube. While the heat welding process is stopped;
A method for manufacturing a parallel tube assembly. Heating and heat setting the heat welded tube;
The manufacturing method of the parallel tube assembly of Claim 3 . The tube is wound around a bobbin and includes a step of unwinding the tube from the bobbin;
The manufacturing method of the parallel tube assembly of any one of Claim 1 thru | or 4 . The tube has two layers of an inner layer and an outer layer disposed outside the inner layer, and the inner layer polymer material is formed of a material having a crystal melting temperature higher than that of the outer layer polymer material;
The manufacturing method of the parallel tube assembly of any one of Claim 1 thru | or 5 . The polymer material of the outer layer is an ethylene / α-olefin copolymer, and the polymer material of the inner layer is polyethylene;
The manufacturing method of the parallel tube assembly of Claim 6 . The tube is a multilayer tube having an intermediate layer of an ethylene-vinyl alcohol copolymer between the outer layer and the inner layer;
The manufacturing method of the parallel tube assembly of Claim 6 or Claim 7 .

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