JP4022977B2 - Mold for making a medical bag and method for manufacturing a medical bag using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mold for making a medical bag such as a blood bag and various chemical solution bags.
[0002]
[Prior art]
A medical bag usually has two plastic films stacked and welded at the periphery, or a tube-shaped film is crushed to weld the opening edge to form a bag body, and then various openings are formed in the opening. A port portion to which a tube or the like is attached is attached, and both are welded while pressing the peripheral surface of the attachment portion in the same manner.
[0003]
In forming the bag body, a bag-making mold is usually used that heat-welds while pressing a welded portion of a plastic film. However, in the welding method using a conventional mold for bag making, as shown in FIG. 4, the repulsive force of the film pressed at the end of the mold acts, and the end is heated and melted / softened. The stretched film is stretched to form thin portions and pinholes. This repulsive force appears more in the vicinity of the fold of the blown film. Moreover, such a tendency appears notably when welding the opening part and port part of a bag main body. In this case, it is pressed with a stronger force.
[0004]
Moreover, when a tube-shaped film (inflation film) is used, bubbles tend to collect at the folds on both side edges, and the bubbles may remain continuously after welding.
[0005]
These thin-walled portions and residual portions of bubbles may be damaged during the manufacturing, storage, and distribution process of medical bags, and may cause problems such as liquid leakage during the distribution process after filling with chemical solutions. Therefore, there is a demand for a technique for reliably preventing the occurrence.
[0006]
Several solutions have already been proposed. That is, Japanese Utility Model Publication No. 3-57240 proposes that bubbles are dispersed to prevent liquid leakage by re-press welding the both side edge welds of the bag body.
[0007]
Japanese Patent Publication No. 4-36552 discloses a non-heated non-conductive portion 5 which is provided adjacent to the pressing portion 4 and a step with the pressing portion 4 in order to prevent the occurrence of a thin portion or a crack at the time of welding with the die. And a space 15 is provided between them, and the resin melted and pushed out by the pressing portion 4 is accumulated in the space 15 so that the portion that tends to become a thin portion is reinforced as a raised portion 16. Proposed.
[0008]
[Problems to be solved by the invention]
However, the above-mentioned improved technology is not fully satisfactory. For example, productivity is poor in the so-called “double strike” in which the former is press-welded again. In the latter method, the mold to be used is composed of two members, a certain space is provided between them, and the level of the lower end surface in contact with the film of these members is intentionally different. The shape is rather complicated and disadvantageous in terms of cost. In addition, the molded product bag has sharp burr-like protrusions corresponding to the space portion, and is not only inferior in appearance, but also may cause trouble in handling the medical bag.
[0009]
Under such circumstances, the present invention has a simpler structure, is advantageous in terms of cost, and of course, a port portion where defects are likely to appear, in addition to the welded portion of the bag body portion of the formed medical bag. There are no defects such as pinholes or thin-walled parts in the welded area on the peripheral surface, so there is no risk of liquid leakage, and there are no unnecessary obtrusive protrusions on the medical bag and it looks good. The purpose is to provide a mold.
[0010]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have adopted a structure in which a non-heating portion is provided adjacent to a heating welding portion for heating a plastic film without a step as a mold structure (see FIG. 1). Then, the adjacent non-heated part is lower than the heated part due to the heat from the heat-welded part, but the film pressed at a considerably high temperature temporarily welds it with a weak welding force, so that the end part on the bag body side By suppressing the repulsion of the film, it was found that even if the film melts and softens at the end, it can be prevented from being stretched, and the present invention has been achieved.
[0011]
That is, the present invention
(1) A medical bag making mold for welding a plastic film to form a medical bag, the mold having a plastic film along a portion corresponding to a welded portion on the outer edge of the main body of the medical bag A heated welded part that heats the heater while pressing, and a non-heated part made of a heat resistant resin that is heated from the heated welded part adjacent to the inside of the welded part and temporarily welds the film A mold for making a medical bag, which is formed on the same plane where the portions in contact with the plastic film on both sides are continuous,
(2) A medical bag making mold for forming a medical bag by welding a plastic film, wherein the mold is welded between an opening of the medical bag main body and a port portion attached thereto. A heat-welded portion that heats a heater while pressing a plastic film along a portion corresponding to the portion, and a heat-resistant resin that is heated from the heat-welded portion adjacent to the inside of the welded portion and temporarily welds the film A medical bag bag mold formed of a non-heated portion made of a heat-resistant resin and having the same peripheral surface where the portions in contact with the plastic film of both portions are continuous,
( 3 ) A method for producing a medical bag, wherein a plastic film is welded using the mold for making a medical bag according to (1) or (2),
About.
[0012]
The mold for making a medical bag of the present invention has a heat welding part for heating while pressing a plastic film, and a part adjacent to the inside (on the bag body side) and in contact with the film is the same as the welding part. It is important to be composed of a flat surface or a non-heated part provided to be the same peripheral surface, and other matters are not particularly limited. The heating welding part has a heater built therein, and the heating welding part is heated to such an extent that the heating welding part itself can press and melt the plastic film. Further, since the non-heated part is adjacent to the heat-welded part, it itself does not have a heater, but receives heat from the high-temperature heat-welded part and is considerably hotter than the heat-welded part. Therefore, the film pressed by this non-welding part is temporarily welded with a weak force. Since the temporary welding force can suppress the stretching phenomenon due to the repulsive force of the film at the end of the heating portion, it is possible to prevent the formation of a thin portion and a pinhole at the end of the heating portion. A non-heating part is comprised from heat resistant resin. For example, polysulfone, polyarylate, polyetherimide, polyethersulfone, polyamideimide, polyetheretherketone (PEEK) and the like are preferable. In addition, the mold surface is coated with a fluororesin so that the melted film does not stick to the mold surface when the plastic film is welded to the mold, or a fluororesin film or sheet is applied. It is preferable to do. And the said metal mold | die has a shape which presses a plastic film along the site | part corresponding to the main body outer edge weld part of a medical bag, or the weld part of a main body and a port part. Further, the mold may have a shape that forms only the outer periphery welded portion of the main body, a shape that forms a welded portion between the main body and the port portion, or a shape in which these are integrated.
[0013]
The welded portion between the opening of the medical bag main body and the port portion to which a tube or the like for supplying and discharging a chemical solution is formed forms a peripheral surface while the welded portion of the main body portion forms a flat surface. . The cross-sectional shape of the peripheral surface is not particularly limited, such as a circle, an ellipse, or a polygon. Further, the main body opening can be provided at any part of the bag.
[0014]
The heating of the plastic film by the mold of the present invention may be performed only from one side of the plastic film or from both the front and back sides. If it is configured to press the heating by the heating unit with a built-in heater only from one side, it becomes one-sided heating and faces the mold (upper mold) through a film to which the mold (upper mold) is to be welded. Thus, if a metal mold | die (lower mold | type) is arrange | positioned, it will become the heating from both surfaces of a film. However, it is practical to weld the port portion only from the outer peripheral surface of the port portion. When the main body is welded from both sides of the plastic film, the lower mold may have the same shape as the upper mold.
[0015]
The plastic film used in the present invention may be in the form of a tube or a sheet and is not particularly limited as long as it is a material that can be welded by heating with a heater. Polyolefin such as low-density polyethylene, high-density polyethylene, and polypropylene, polystyrene, AS resin, ABS resin, acrylic resin, vinyl chloride resin, nylon and the like are preferable.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional explanatory view schematically showing an example of a mold of the present invention. This mold replaces the conventional mold (FIG. 4) consisting only of the heat-welded part, and is adjacent to the bag body side of the heat-welded part (that is, the heater built-in part). That is, it is a mold that includes a heater non-incorporating portion and is configured so that the portions in contact with these films are on the same plane. According to this mold, the stretch phenomenon due to the repulsive force of the melted / softened film at the end of the bag body side of the heat-welded part is caused by the repulsive force of the non-heated part being heated from the heat-welded part, resulting in a weak force. Can be suppressed by temporarily welding.
[0017]
For this reason, the bag welded by the mold of the present invention does not show a defect such as a thin wall portion seen at the end of the weld as in the prior art, and can solve the risk of liquid leakage.
[0018]
FIG. 2 illustrates another embodiment of the present invention, which is an explanatory view of a mold for welding a port portion to an opening of a bag body. In the figure, the opening of the bag body and the port part are combined and arranged so that the port part is placed on the semicircular part at the center part, and the upper die of the same shape is pressed on this and the heater is heated and welded.
[0019]
Normally, the film at the bag body opening is pressed with a stronger force against the rigid port portion, so that the film stretching that occurs at the end of the conventional mold (welded portion) in FIG. 5 is performed as shown in FIG. The phenomenon is more pronounced.
[0020]
However, by using the mold of the present invention as shown in FIG. 2, it is possible to prevent the occurrence of the stretching phenomenon as schematically illustrated in FIG.
[0021]
What is shown in FIG. 7 is a front view showing an example of a medical bag manufactured by the mold of the present invention. 8 is a right side view in the vertical direction in FIG. 7, FIG. 9 is a left side view thereof, FIG. 10 is a side view of the upper end portion (plan view) in FIG. 7, and FIG. As is clear from these figures, this medical bag has a shape in which two transparent or opaque films are overlapped and the peripheral edge portion and the port portion are welded, and the front and back sides are in a palm-like shape. is there. In other words, the medical bag itself has a light planar shape except for the port portion. Moreover, the temporary seal part formed with the weak welding force across this can also be formed in the constriction part of a bag center. FIG. 12 shows a longitudinal side view of the medical bag filled with a medical solution (the left side and the right side are substantially the same as in FIGS. 8 and 9). FIG. 13 shows a case where the constricted portion does not have a temporary seal portion. The temporary seal portion separates and holds the drug solution and the drug in the two storage portions partitioned by the temporary seal portion. Then, when necessary, the bag can be pressed to break the seal portion, and the contents in the two storage portions can be mixed. The constricted portion has an effect of concentrating stress on the seal portion and easily breaking.
[0022]
Moreover, it can replace with the said temporary seal part and can also use the clamp which can be opened and closed freely. FIG. 13 is a vertical side view with no temporary seal portion or with the temporary seal portion broken (again, the left side surface and the right side surface are substantially the same as in FIGS. 8 and 9). Further, FIGS. 14 to 19 show other medical bag shapes. FIG. 14 is the same except that the shape of the port portion in FIG. 7 is different. Accordingly, FIGS. 15 to 19 corresponding to FIGS. 8 to 13 have the same shape as FIGS.
[0023]
(Example of manufacturing medical bags)
The medical bag shown in FIG. 7 was manufactured using the mold of the present invention. As shown in FIGS. 1 and 2, a member molded from polyether ether ketone as a non-heating part is adjacent to a heat welding part, which is a conventional mold, and no step is formed on the film pressing surface. Thus, they were formed on the same plane or the peripheral surface. The film used was a polyethylene tubular film (inflation film). First, the main body was welded by pressing a mold (upper mold) shaped along the outer edge of the main body of the medical bag against the film on the receiving plate (FIG. 1). At this time, the heating and welding part of the mold was heated to 160 ° C., and the sealing time was 5 seconds. Next, a non-welded portion (opening portion) of the main body portion was combined with a separately manufactured tube-shaped port portion, and the mold having the shape shown in FIG.
[0024]
In order to evaluate the welded part (port part) of the medical bag thus welded, the tensile strength was measured by a strograph. As a result, it was 12.86 kg. For comparison, the port portion of the medical bag welded using a conventional mold not provided with a non-heated portion was only 6.35 kg.
[0025]
【The invention's effect】
As described above, the mold of the present invention has a simpler configuration in which a non-heating portion that suppresses repulsion of the film by temporary welding of the film is provided adjacent to the heater heating welding portion without a step. It is possible to prevent liquid leakage by suppressing the occurrence of defects such as a thin-walled portion seen in the heater heating weld portion.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing an example of a mold according to the present invention.
FIG. 2 is a diagram schematically illustrating another embodiment of the mold of the present invention, and is an explanatory diagram of a welding mold for a port portion.
FIG. 3 is an explanatory diagram when the mold of FIG. 2 is used, in which a non-welded part temporarily welds a film to suppress the repulsive force, and a state such as a thin-walled part does not occur at the welded end. This is shown schematically.
FIG. 4 schematically shows a state in which when a conventional mold is used for welding, a film melted and softened by the repulsive force of the film at the end of the mold is stretched to form a thin portion.
FIG. 5 is an explanatory view of a conventional port portion welding mold.
FIG. 6 schematically shows a state in which a thin film portion is formed by stretching a film melted and softened by the repulsive force of the film in the case where welding is performed using the same mold as above.
FIG. 7 is a front view showing an example of a medical bag manufactured by the mold of the present invention.
FIG. 8 is a right side view in the vertical direction in FIG.
FIG. 9 is a left side view of the above.
10 is a side view (plan view) of an upper end portion in FIG. 7. FIG.
11 is a side view (bottom view) of the lower end portion in FIG. 7. FIG.
12 is a longitudinal side view showing a state in which a medical bag having a temporary seal portion provided in the constricted portion of the bag shown in FIG. 7 is filled with contents. FIG.
FIG. 13 is the same as above, when there is no temporary seal portion, or when the temporary seal portion is broken.
FIG. 14 is a front view showing another type of medical bag manufactured by the mold of the present invention.
15 is a right side view or a left side view in the vertical direction in FIG.
16 is a side view (plan view) of the upper end portion in FIG. 14;
FIG. 17 is a side view (bottom view) of the lower end part of the above.
18 is a longitudinal side view showing a state in which a medical bag in which a temporary seal portion is provided at the constricted portion of the bag shown in FIG. 14 is filled with contents. FIG.
FIG. 19 is the same as above, when there is no temporary seal portion, or when the temporary seal portion is broken.

Claims (3)

A medical bag-making mold for forming a medical bag by welding a plastic film, wherein the mold presses the plastic film along a portion corresponding to a welded portion on the outer edge of the main body of the medical bag. of a non-heated part of a heat-resistant resin adjacent to the inner temporarily welded are heated film from the heating welded portion with respect to heat welding portion and solution deposition unit for heater heating, and a plastic film both parts A mold for making a medical bag, which is formed by forming the same plane in which the portions in contact with each other are continuous. A mold for making a medical bag for forming a medical bag by welding a plastic film, the mold corresponding to a welded portion between an opening of the medical bag main body and a port portion to be attached thereto A heat-welded portion comprising a heat-welded portion that heats a heater while pressing a plastic film along a portion to be heated, and a heat-resistant resin that is heated from the heat-welded portion adjacent to the inside of the welded portion and temporarily welds the film A mold for making a medical bag made of a non-heated portion made of a functional resin and having the same peripheral surface where the portions in contact with the plastic film of both portions are continuous.   A method for producing a medical bag, wherein a plastic film is welded using the mold for making a medical bag according to claim 1 or 2.

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