JP4375545B2 - Film and structure welding method, welding mold, medical bag manufacturing method using the same, and medical bag - Google Patents

Description

  The present invention relates to a method for welding a film or the like, a method for welding a structure having a three-dimensional shape to a thin bag-like material such as a film, and a mold used for the method. Specifically, the present invention particularly relates to a mold for welding structures such as various ports or tubes in the manufacture of medical bags such as blood product bags and various drug solution bags, and medical bags using the same. It relates to the manufacturing method.

  Medical bags filled with blood products and various drug solutions are usually stacked with two plastic films, and the periphery is pressed and welded, leaving an opening for mounting a port to which various tubes are attached, Alternatively, after forming the bag body by welding the opening edge of the tube-like film, leaving the opening for attaching the port or the like, the desired various ports or structures such as tubes are attached to the opening. It is mounted and the periphery of the mounting portion is similarly pressed and welded.

  In the formation of the medical bag, a so-called mold for bag making, which is usually heat-welded while pressing a welded portion of a plastic film, is used. However, in the conventional mold for bag making, since the entire mold part is heated, the repulsive force of the pressed film acts on the end of the mold and is heated and melted at the end of the mold. -The softened film was stretched, and as a result, thin portions, pinholes, bubbles, or film breakage were easily formed. This tendency is prominent when a port or the like is attached to the opening of the bag body and pressed and welded, since the pressing force is particularly strong.

  Such thin-walled parts may damage the bag itself during the manufacturing, storage, and distribution process of medical bags, and may cause inconveniences such as liquid leakage during filling and storage of the medical solution during storage and distribution processes. It was also the cause of defective products.

  As a method of improving such inconvenience, by disposing a non-heated part without a step in the heat-welded part of the mold, the repulsive force of the melted / softened film is suppressed by temporary welding, thereby reducing the thin-walled part. A means for preventing the occurrence of the above has been proposed (Patent Document 1).

  That is, the mold proposed in Patent Document 1 is provided with a non-heated portion adjacent to a heat-welded portion for heating a plastic film without a step, so that the adjacent non-heated portion is heated from the heat-welded portion. However, the film pressed at this non-heated part is temporarily welded with a weak welding force, and the repulsive force of the film at the end on the bag body side. It is said that even if the film melts and softens at the end, it can be prevented from stretching.

  In the manufacture of a medical bag using such a mold, it is effective in forming the bag body, but it is still sufficient when a structure such as various ports is attached and pressed and welded. It couldn't be said. That is, in the mounting of a structure such as a port to the opening after the formation of the bag body in the medical bag, and in pressing and welding, a structure composed of a raw material different from the plastic raw material of the bag itself is mounted, It is welded integrally with the film of the bag. Therefore, it is necessary to considerably increase the welding heating temperature, and the pressing force is stronger than the pressing force at the time of forming the bag body. Therefore, the repulsive force due to the deformation of the film is greater at the base of the mounting portion of the structure such as the port, and if the heating is insufficient, liquid leakage due to poor welding occurs. In addition, since it is difficult to control the temperature in the non-heated part, the heated and melted / softened film is stretched by the pressure of the non-heated part, so that a thin part, pinholes, bubbles and the like are easily formed.

Therefore, there is a need for the development of a mold for ensuring more effective welding without the occurrence of such problems when mounting, pressing and welding structures such as ports in the manufacture of medical bags. Current situation
Japanese Patent Laid-Open No. 11-254558

  In view of the above-mentioned present situation, the present invention generates pinholes, thin parts, etc. in the surrounding welded part when attaching, pressing and welding various ports, tubes and other structures to the bag body in the manufacture of medical bags. Therefore, it is an object of the present invention to provide a mold for welding a structure free from problems such as liquid leakage, a welding method using the mold, and the like.

  As a result of diligent investigations to solve such problems, the present inventors, as a mold structure for welding a structure such as a port in the manufacture of medical bags, to heat, press and weld a plastic film, A pinhole is formed in the welded part around the structure by providing a heating part that is the film melting temperature for welding the film and a non-heating part that is equal to or lower than the melting temperature, and providing a temperature gradient in the non-heating part. In addition, the boundary between the welded portion and the non-welded portion around the structure can be prevented by adopting a configuration that prevents the non-heated portion from being pressed by the heated portion. The layer thickness in the part was found to be uniform, and the present invention was completed.

That is, the present invention has the following basic aspects:
(1) A mold for welding a structure to a bag made of a plastic film, wherein the mold has a heating portion that maintains the melting temperature of the plastic film and a non-melting temperature that is equal to or lower than the melting temperature adjacent thereto. The mold comprising a heating part, wherein a temperature gradient is provided in the non-heating part;
(2) The temperature gradient provided in the non-heating part is performed by changing the layer thickness of the non-heating part and / or by embedding a metal part in contact with the heating part in the non-heating part. Molds;
(3) The layer thickness of the non-heating part adjacent to the heating part is formed so as to become thinner toward a mold recess for pressing and welding the structure to the bag. Mold;
(4) There is a difference between the diameters of the recesses in the heating part in the mold recess for pressing and welding the structure to the bag and the non-heating part adjacent thereto, and the pressing force of the mold on the structure in the non-heating part The mold according to the above 1, 2 or 3, which is formed so as not to be applied;
(5) The mold according to the above 1, 2, 3 or 4, wherein the non-heated part is made of a heat resistant resin;
(6) The mold according to 1, 2, 3 or 4 above, wherein the heating part and / or the non-heating part of the mold is coated with a fluororesin;
(7) The mold according to any one of 1 to 6 above, wherein the structure to be welded to the bag is a round port, a rhombus port, an elliptical flat port or a tube;
(8) The mold according to any one of 1 to 7 above, wherein the bag is a medical bag;
It is.

Moreover, this invention is another aspect,
(9) A method of manufacturing a bag, particularly a medical bag, characterized in that a structure is welded to the bag body using the mold described in 1 to 8 above;
It is.

As another aspect, the present invention provides:
(10) A method of welding a structure to a bag made of a plastic film, as a welding mold, from a heating part that maintains the melting temperature of the film and a non-heating part that is equal to or lower than the melting temperature adjacent thereto And using the mold provided with a temperature gradient in the non-heated part;
(11) The method according to 10 above, wherein the temperature gradient provided in the non-heated part in the method is carried out by changing the layer thickness of the non-heated part or by embedding a metal part in contact with the heated part in the non-heated part;
(12) The method according to 11 above, wherein the layer thickness of the non-heating part adjacent to the heating part is formed so as to become thinner toward a mold recess for pressing and welding the structure to the bag;
(13) The mold used in the above method has a difference in the diameters of the recesses between the heating part in the mold recess for pressing and welding the structure to the bag and the non-heating part adjacent to the heating part. The method according to 10, 11, or 12, wherein the mold is formed so that a pressing force of the mold is not applied to the structure at the part;
(14) The method according to 10 to 13, wherein the bag is a medical bag;
It is.

  In medical bags such as blood product bags and various drug solution product bags, defects such as pinholes and thin parts, liquid leakage, etc. are fatal defective products. However, by using the mold of the present invention, by using a welding mold for a structure such as a port in a medical bag, a pinhole or a thin wall at a welded portion around the structure that has conventionally occurred is used. Therefore, there can be produced a medical bag that does not have a defect such as the occurrence of a part and does not have a problem such as liquid leakage.

  In particular, the mold provided by the present invention includes a heating part and a non-heating part adjacent thereto, and a temperature gradient is provided in the non-heating part. In other words, the welded part of the structure such as the port is different from the welded peripheral part of the bag body, and the film is deformed and welded to a greater extent, so that the repulsive force of the film increases and a high temperature is required for welding. On the other hand, the remaining mold plane part merely presses the film, so there is no repulsive force of the film and it is easily welded even at a low temperature. The metal mold | die of this invention can perform this point by providing a temperature gradient to the non-heating part which comprises a metal mold | die.

  The temperature gradient in the non-heated part is formed so that the difference in the layer thickness of the non-heated part adjacent to the heated part, i.e., the thickness becomes thinner toward the concave part of the mold where the structure is pressed and welded. A temperature gradient is easily given to the non-heating part which comprises a metal mold | die by making the heating part embed the metal part which an edge part contact | abuts to a heating part.

  Further, since the diameter of the non-heated portion is slightly larger than the diameter of the heated portion in the welded portion of the structure, an unreasonable force is not applied to the non-heated portion. If the diameters are the same, the film is pressed without melting in the non-heated part, and the film is forced and thinned at that part, and a thin part is formed. The mold provided by the present invention can prevent the formation of such a thin portion.

  Further, by covering the heating part and / or the non-heating part of the mold with a fluororesin, the film can be prevented from being cut and the formation of a sharp thin part of the film can be prevented.

  The structure welding mold provided by the present invention, in particular, a medical bag port or the like includes a heating part that inserts a port or the like into an opening of a bag body of a plastic film and heats it while being pressed, It is basically composed of a non-heating part provided adjacent to the bag body side), and a temperature gradient is provided in the non-heating part, and further, a heating part in a mold recess for pressing and welding the structure It is preferable to provide a difference in both the diameter of the metal and the diameter of the non-heated portion so that the pressing force of the mold is not applied to the non-heated portion.

  The heating unit includes a heater or a heating medium therein, and is maintained at a temperature at which the heating unit can press and melt the plastic film by the heater or the heating medium. On the other hand, since the non-heated part is adjacent to the heating part, it receives heat from the heating part even if it does not have a built-in heater, becomes a considerably high temperature although it is lower than the heating part, and the film is stretched temporarily. Therefore, melting and welding (pseudo welding) are performed. However, in the present invention, by intentionally providing a temperature gradient in the non-heated part, the film around the structure in the non-heated part is smoothly stretched and pseudo-welded. As a result, after the structure is welded, there is no excessive repulsive force applied to the film, so thin parts, pinholes, bubbles, etc. There is no occurrence.

  A non-heating part is comprised from heat resistant resin. As such a heat resistant resin, for example, polysulfone, polyacrylate, polyetherimide, polyethersulfone, polyamideimide, polyetheretherketone (PEEK) and the like are preferable. In addition, when a plastic film is welded to the mold, the molten film may be coated with a fluororesin so that the molten film does not stick to or adhere to the mold surface, or the fluororesin film or sheet may be coated. It is preferable to keep it.

  In addition, since the mold provided by the present invention is particularly for mounting, pressing and welding ports, tubes, etc. to the medical bag body, the outer peripheral portion of the structure is integrally welded with a plastic film. Is done. Therefore, in the mold, the upper mold and the lower mold have basically symmetrical shapes opposite to each other, and both of them (upper mold and lower mold) are heated with the film. Welding is performed.

The plastic film constituting the bag used in the present invention may be a tube shape or a sheet shape, and the film itself may be a single layer film or a laminated film. The material is not particularly limited as long as the material can be welded by heating and pressing. Such film materials include polyolefins such as low density polyethylene, high density polyethylene, polypropylene, polystyrene, acrylonitrile / styrene copolymer resin (AS resin), acrylonitrile / butadiene / styrene copolymer resin (ABS resin), and acrylic resin. And thermoplastic resins such as vinyl chloride resin and nylon.
Among them, the mold provided by the present invention is preferably used for manufacturing a medical bag using a single layer film.

  Examples of the structure to be welded to the bag include various ports such as a round port, a diamond port, and an elliptic flat port, and various tubes. These various ports or tubes are also basically made of hard plastic, and can be selected from those that are melted and attached to a desired medical bag and exhibit a desired function.

In the following, the present invention will be described in detail by way of examples based on the drawings.
FIG. 1 is a perspective view schematically showing a basic embodiment of a mold (lower mold) 1 of the present invention. This mold is composed of a metal heating part 10 and a non-heating part 20 made of a heat-resistant resin adjacent to the metal heating part 10 instead of the conventional metal welding part made of metal. 1 has a semicircular mold recess 30 in which a round port (not shown in the figure) as a structure is mounted, pressed and welded. A round port inserted into the opening of the medical bag body is placed in the mold recess 30 integrally with the film and has a symmetrical shape with the mold (lower mold) 1 (upper mold). It is integrally welded to the bag by heating and pressing [not shown in the figure].

  In this embodiment, the metal heating unit 10 and the non-heating unit 20 made of heat-resistant resin adjacent to the metal heating unit 10 are provided with non-heating units 21 and 22 so as to surround the entire heating unit 10. The unit 20 is arranged to be pedestaled on the upper part of the heating unit 10.

  In this case, in the mold (lower mold) 1 of the present invention, the non-heating part 20 adjacent to the metal heating part 10 has its end part and a part thereof in contact with the heating part 10. The metal part 11 is embedded in the form. In addition, the said metal part 11 should just have the edge part contact | abutted to the heating part 10, and may be comprised integrally with the metal heating part 10. FIG.

  The metal part 11 is preferably embedded in the vicinity of a mold part (mold recess 30) that presses and welds the round port. By burying the metal part 11 in the heating part 10 and the non-heating part 20 adjacent thereto, the non-heating part 20 receives heat from the heating part 10 without a heating medium such as a heater inside. The temperature in the heating unit 20 ensures a gradient temperature distribution in the horizontal direction on the surface.

  That is, the vicinity of the arrow 100 in the figure has a temperature distribution close to maintaining the melting temperature of the film in the heating unit 10, but a temperature distribution lower than that is secured in the vicinity of the arrow 200 in the figure. That is, a temperature gradient is provided. Therefore, in the stage where the film is heated and pressed by the mold (lower mold, upper mold), near the arrow 100, the film has a very smooth pseudo-weld. Although it does not occur, the film is softened by heating, and the film is not stretched excessively against deformation due to pressing of the mold. Therefore, the round port welded to the bag is welded integrally with the bag by melting the film in the metal heating part 10, while preventing the formation of a thin part of the film by pseudo welding at the boundary part, In addition, a very good bag and round port are welded so that the film itself is not welded at other portions.

  Further, in the mold (lower mold) 1 of the present invention, the diameter of the heating part 10 and the non-heating part 20 in the mold part (mold recess 30) for pressing and welding the round port is set. A difference is provided so that the pressing force of the mold 1 is not applied to the round port in the non-heating portion 20. This state is shown in FIG. 2 as a schematic state seen from the plane direction of the mold (lower mold) 1 shown in FIG.

  That is, in FIG. 2, the diameter (b) of the non-heating part 20 in the mold part (mold recess 30) that presses and welds the round port is somewhat larger than the diameter (a) of the heating part 10. The round port mounted in the mold recess 30 is formed so as not to be pressed in the non-heating part 20 even when pressed by the lower mold and the upper mold.

  In addition, since the boundary part between the diameter (b) of the non-heating part 20 and the diameter (a) of the heating part 10 in the mold part (mold recess 30), the pseudo welding at the part is performed more smoothly. The taper is cut with a tapered surface from the heating unit 10 toward the non-heating unit 20 (31 in the figure).

  The diameter (a) of the heating unit 10 and the diameter (b) of the non-heating unit 20 can be basically determined as follows. That is, in the heating unit 10, since the round port attached to the opening of the bag body needs to be pressed and welded integrally with the film of the bag, the diameter (a) is [round port Diameter + film thickness], or a somewhat smaller diameter to the extent that the desired pressing force is applied. On the other hand, since the diameter (b) of the non-heating portion 20 is formed so as not to apply the pressing force of the mold, the diameter is larger than [diameter of round port + film thickness]. Specifically, it is preferable that the diameter of the heating unit 10 determined above is increased to about 1 mm.

  Further, in the present embodiment, the metal heating unit 10 and the non-heating unit 20 made of heat-resistant resin adjacent thereto are provided with non-heating units 21 and 22 so as to surround the entire heating unit 10, The non-heating unit 20 is disposed so as to be positioned above the heating unit 10. In this case, the non-heating portion 21 is provided as a portion where there is no heating / pressing of the film in this portion, and the non-heating portion 22 on the left and right sides of the mold 1 is provided in a round shape. It is possible to prevent deformation due to melting of the film by the heating unit 10 in the part where the bag is already welded, except for mounting the port.

  Furthermore, in the non-heating part 20, in the mold recess 30 in which the round port is mounted, a part of the mold is cut off so that the bag body side is not heated from the mold. It is preferable to prevent the film from being cut on the bag body side of the mold port. The size of the cut portion of the mold may be cut so that the round port does not come into contact with the mold. A schematic diagram of such a mold is shown in FIG. In addition, each code | symbol in FIG. 3 has the same meaning as FIG. In the figure, in the mold recess 30 in which the round port is mounted, a cut portion 32 can be provided on the bag body side to prevent the film from being cut at the end of the round port. In the embodiment shown in FIG. 3, each part exhibits the same function as that shown in FIG.

  According to the mold of the present invention configured as described above, the round port mounted in the opening of the bag body is mounted in the mold recess 30, and the round is pressed by pressing the lower mold and the upper mold. The mold port is welded together with the film. In this case, in the round port welded portion, the diameter (b) of the non-heating portion 20 is slightly larger than the diameter (a) of the heating portion 10, so that an unreasonable pressing force is applied to the non-heating portion 20. It doesn't take. If the diameters are the same, in the non-heated part 20, since the temperature is equal to or lower than the melting temperature of the film, the film is pressed without being melted. Part is formed.

  However, since no pressing force is applied to the non-heating part 20, the film is not deformed excessively. In addition, the non-heating part 20 receives heat from the heating part 10 and further embeds a metal part 11 whose end part comes into contact with the heating part in the non-heating part 20 adjacent to the heating part 10. A desired temperature gradient is given to the non-heated part constituting the mold, and the film is temporarily welded, that is, pseudo welded even if it is not pressed, and this pseudo weld causes the repulsive force of the film at the end of the heated part. The stretching phenomenon can be suppressed.

  For this reason, the round port mounted, pressed and welded to the bag body by the mold provided by the present invention is free from defects due to the thin wall portion of the film seen in the conventional port portion, such as liquid leakage. A medical bag without worry is produced.

In the embodiment described above, the temperature distribution in the non-heating part 20 is ensured by embedding the metal part 11 in the heating part 10 of the mold (lower mold) 1 and the non-heating part 20 adjacent thereto. In one embodiment, the non-heating unit 20 adjacent to the heating unit 10 of the mold is arranged in a form surrounding the entire heating unit 10 while being pedestaled by the heating unit.
However, the arrangement of the non-heating unit 20 can employ various modifications depending on the form of the bag to be heated, pressed and welded.

  Another embodiment of a mold based on this modification is shown in FIG. The reference numerals in the figure are the same as those in FIG. In the present embodiment, the non-heating unit 20 is disposed in a part of the heating unit 10, and the temperature gradient in the non-heating unit 20 is ensured by embedding the metal unit 11 in the non-heating unit 20. The same effect is demonstrated.

  Moreover, each Example demonstrated above is the temperature gradient in the non-heating part 20 by embedding the metal part 11 in the heating part 10 of the metal mold | die (lower mold) 1 and the non-heating part 20 adjacent to it. In this embodiment, the temperature distribution is ensured, but the metal part 11 is not embedded in the non-heated part 20, and an intentional temperature gradient distribution can be secured by the difference in the layer thickness of the non-heated part 20. it can.

Another such embodiment is shown in FIG. The reference numerals in the figure are the same as those in FIG. In this example, unlike Example 1, the non-heating part 20 adjacent to the heating part 10 is not embedded with the metal part 11 contacting the heating part 10, and the layer thickness of the non-heating part 20 is The structure is formed so as to become thinner toward the mold recess 30 for pressing and welding the structure to the bag. Even in this case, the thin portion of the non-heated portion 20 receives heat from the heated portion 10 and consequently becomes higher than the hot portion of the layer. As a result, a temperature-gradient distribution is ensured, and the same effects as in the previous embodiments are exhibited.
The horizontal temperature gradient distribution on the surface of the non-heated part 20 can be performed by both embedding the metal part in the non-heated part and changing the layer thickness.

  In the above embodiment, the medical bag is used as the bag and the round port is used as the structure as an example. However, other bags may also be used, such as a port, for example, a rhomboid port, an ellipse. Even when a flat port or tube is attached to a medical bag and pressed or welded, there is basically no change, and the shape of the mold recess 30 is determined according to the shape of each structure. It is only done.

  As described above, the welding mold for a structure such as a port with respect to a bag provided by the present invention eliminates the occurrence of pinholes and thin parts at the welded portion around the structure, which has conventionally occurred. Therefore, the manufacturing cost can be reduced because a medical bag can be manufactured without problems such as liquid leakage.

It is a typical perspective view which shows Example 1 of the metal mold | die of this invention. It is the typical explanatory view which looked at the metallic mold of Example 1 of the present invention from the plane direction. This is a modification of the first embodiment of the present invention. It is a typical perspective view which shows another Example 2 in the metal mold | die of this invention. It is a typical perspective view which shows another Example 3 in the metal mold | die of this invention.

Explanation of symbols

1 Mold (lower mold)
DESCRIPTION OF SYMBOLS 10 Heating part 11 Metal part 20 Non-heating part 21 Non-heating part 22 Non-heating part 30 Mold recessed part 31 Tapered surface 32 Cutting part

Claims (12)

A mold for welding a structure to a bag made of a plastic film, the mold including a heating part that maintains a melting temperature of the plastic film, and an unheated part that is equal to or lower than the melting temperature adjacent thereto. The mold according to claim 1, wherein the non-heated portion is provided with a temperature gradient by embedding a change in the layer thickness of the non-heated portion and / or a metal portion contacting the heated portion in the non-heated portion . 2. The mold according to claim 1 , wherein a layer thickness of a non-heated part adjacent to the heating part is formed so as to become thinner toward a mold recess for pressing and welding a structure to a bag. . There is a difference in the diameter of the recess between the heated part in the mold recess that presses and welds the structure to the bag and the non-heated part adjacent to the heated part, so that the pressing force of the mold is not applied to the structure in the non-heated part The mold according to claim 1 or 2 , wherein the mold is formed as described above. The mold according to claim 1, 2, or 3 , wherein the non-heated portion is made of a heat-resistant resin. The mold according to claim 1, 2 or 3, wherein the heating part and / or the non-heating part of the mold is coated with a fluororesin. The mold according to any one of claims 1 to 5 , wherein the structure to be welded to the bag is a round port, a diamond port, an elliptical flat port, or a tube. The mold according to any one of claims 1 to 6 , wherein the bag is a medical bag. A method for manufacturing a bag, comprising using the mold according to claim 1 to weld a structure to a bag body. A method of welding a structure to a bag made of a plastic film, comprising a heating part that maintains the melting temperature of the film and a non-heating part that is equal to or lower than the melting temperature adjacent thereto as a welding mold. The above-mentioned welding characterized in that the heating part uses a mold provided with a temperature gradient by embedding a change in layer thickness of the non-heating part and / or a metal part contacting the heating part in the non-heating part. Method. The method according to claim 9 , wherein the layer thickness of the non-heating part adjacent to the heating part is formed so as to become thinner toward a mold recess for pressing and welding the structure to the bag. The mold used in the method has a difference in the diameter of the concave portion between the heating portion in the mold concave portion that presses and welds the structure to the bag and the non-heating portion adjacent thereto, and the non-heating portion has a structure. The method according to claim 10 , wherein the mold is formed so that a pressing force of the mold is not applied to the object. The method according to any one of claims 9 to 11 , wherein the bag is a medical bag.

Images