JP2004148578A - Bag making method - Google Patents

Abstract

A method of welding a mouth member made of a synthetic resin and a bag portion made of a flexible film, in particular, a bag making method excellent in liquid-tightness of a welded portion between the mouth member and the bag portion, and the manufacturing method. Providing manufactured medical containers.
A bag-making method in which a mouth member 1 made of a preheated synthetic resin and a bag portion 2 made of a flexible film are welded and integrated, and the bag of the mouth member 1 at the time of preheating. A preheating step of softening the synthetic resin of the welded portion (mouth member welded portion) 12 between the mouth member 1 and the bag portion without softening the synthetic resin of the side end portion (mouth member end portion) 11; A manufacturing method including the step of inserting the opened mouth member 1 into the opening portion of the bag portion and pressing the sealing member 1 to weld the mouth member welding portion 12 and the opening portion, and the bag making method A medical container characterized by.
[Selection] Figure 1

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bag making method. In particular, the present invention relates to a method of welding a mouth member made of a synthetic resin and a bag portion made of a flexible film, and relates to a bag making method having excellent liquid-tightness of the welded portion between the mouth member and the bag portion. The present invention also relates to a medical container that is used by filling an infusion solution, blood, or the like in a container manufactured by the manufacturing method.
[0002]
[Prior art]
In recent years, instead of glass medical containers, medical containers molded using synthetic resins have been frequently used. In addition, a synthetic resin medical container is manufactured from a container manufactured by blow molding or a film or sheet manufactured by inflation molding or T-die molding (hereinafter, the film or sheet is also referred to as “film”). Containers manufactured from films (hereinafter referred to as “film bags”) are increasing. The reason for this is that the film bag has a thin and uniform container thickness and can be reduced in volume after use, so that the amount of waste is reduced, and the infusion discharge rate at the time of infusion of the contents is almost constant until the end. Is. In order to fill and discharge the contents, a hollow cylindrical mouth member made of synthetic resin having a three-dimensional shape as shown in FIG. 1 is attached to the film bag by heat welding or the like. This mouth member often has a hollow circular or elliptical cross section.
[0003]
The attachment of the mouth member to the film requires a liquid-tight attachment of a three-dimensional shape member to a two-dimensional planar film, but between the film palm portion and the welded portion of the mouth member. A gap 22 as shown in FIG. 2 (hereinafter referred to as “gap between the palms”) may occur and the content liquid may leak. Especially in the case of a thick film having a film thickness of 100 μm or more, depending on the shape of the mouth member, the film is deformed in accordance with the shape of the mouth member at the time of heat welding. In some cases, the welded portion was peeled off. Also, when the mouth member and film are held together with a sealing mold and welded together, there is a danger that excessive tensile stress will occur on the film to match the shape of the mouth member, resulting in thinning of the film or opening of the film. There is.
In order to prevent such film deformation and perforation due to heat, there is a method of laminating a heat-resistant layer on the film with an adhesive and using a laminated film with improved heat resistance. However, it is preferable not to use in the medical field. Therefore, various studies have been made on the adhesive technique in which the bag portion and the mouth member using a single-layer or multilayer film without any eluting matter are liquid-tight and have no gap between the palm portions.
[0004]
As a container that solves the problem of the gap between the palms, a container in which a mouth member having a thin piece 23 extending on the left and right outside of the welded part and a bag part as shown in FIG. 3 is proposed.
Specifically, as a manufacturing method of a container for bonding a container body and a mouth member having a thin piece extending to the left and right outside of a welded portion with a film, a mouth member having a thin piece extended in advance using a preheating jig is manufactured. After that, a method of heat sealing to the infusion bag (see Patent Document 1),
Also, before the plug comes into contact with the film or sheet, the surface of the plug is melted at a temperature 15 to 80 ° C. higher than the melting point of the material of the plug, and at the same time, a melt with a width of 0.2 to 3 mm is formed on both sides of the plug. A method in which two films or sheets are pressed against a plug from a symmetrical direction after forming a wearing tab (see Patent Document 2),
[0005]
On the outer peripheral surface of the hollow cylindrical body, after heating and softening the projecting part, which is constricted with the hollow cylindrical body provided at the control position that bisects the hollow cylindrical body in the vertical axis direction, the projecting part in a flexible state And a method of contacting the sheet with the hollow cylinder (see Patent Document 3),
A method of making a bag by heat-sealing a mouth portion having a fin-like projection formed by a mold with an inflation tube (see Patent Document 4),
[0006]
Before welding the plug to the film or sheet, the surface of the welded portion of the plug is made 13 ° C. above the melting point above the softening temperature of the material of the welded portion of the plug using the radiant heat of the heater at a temperature of 600 to 800 ° C. Heat within a high temperature range, pressurize from both sides of the heated plug with a fin mold symmetrical to the plug, mold fin-shaped flakes on the plug, and then continue heating A method such as a method in which a plug that maintains the above is inserted between a film or sheet and the plug is welded to the film or sheet with a heat sealing mold (see Patent Document 5) is disclosed.
[0007]
These methods are methods in which a mouth member in which a thin piece is extended to the left and right outside of the welded portion between the mouth member and the film is manufactured in advance, and then bonded to the bag portion, and an extra step for forming the thin piece is required. In addition, there are problems such as fluctuations in the size of the flakes, unevenness in the left and right sizes, adhesion of carbide dust from the flake molding die, and shrinkage and twisting of the pre-formed flakes. Deformation such as collapse may occur, and this heating is likely to be accompanied by deformation due to the release of the residual stress in the welded part at the time of injection molding of the mouth member. Accurate position adjustment of the member, the bag part, and the seal mold may be shifted, resulting in insufficient adhesion. Accordingly, there has been a demand for an improvement that further suppresses the occurrence of gaps in the palm portions.
In particular, when the diameter of the mouth member exceeds 10 mm, the film tends to be thinner and more pinholes are generated.
[0008]
[Patent Document 1]
Japanese Utility Model Publication No. 61-194638 [Patent Document 2]
Japanese Patent No. 2940987 [Patent Document 3]
Japanese Patent No. 2791387 [Patent Document 4]
Japanese Patent Laid-Open No. 4-191033 [Patent Document 5]
Japanese Patent No. 3048486 [Patent Document 6]
Japanese Patent Publication No. 3-5304 [0009]
[Problems to be solved by the invention]
The present invention has been made in view of such a situation, and reduces the deformation of the mouth member welded portion during preheating as much as possible, has fewer steps, and stably suppresses the occurrence of a gap between the palm member and the bag. The main object is to provide a bag-making method capable of obtaining a bag with a mouth member having excellent liquid-tightness at the welded portion.
[0010]
[Means for Solving the Problems]
As a result of intensive research on a bag forming method for welding the mouth part and the bag part that can suppress the occurrence of a gap between the palm parts, the present inventors have conducted injection molding by heating at the time of thin piece molding or preheating to the mouth part. Deformation due to release of residual stress at the time of injection molding possessed by the mouth member produced by the above method is difficult, and it is difficult to position the mouth member, bag part and seal mold relatively accurately. It was found that harmful local contact and gaps were generated between the parts, making it difficult to seal uniformly and stably. Therefore, by suppressing the deformation of the mouth member, a stable and uniform thin piece can be formed, and the generation of a gap in the palm portion can be suppressed, and at the same time, the film in the vicinity of the mouth member end portion of the bag portion due to heating of the mouth member end portion It has been found that thinning of the film can be prevented and the present invention has been completed.
[0011]
That is, this invention relates to the bag making method shown by the following [1]-[7].
[1] A bag-making method in which a mouth member made of a preheated synthetic resin and a bag portion made of a flexible film are welded and integrated, and an end portion on the bag side of the mouth member at the time of preheating A preheating step of softening the synthetic resin of the welded portion of the mouth member and the bag portion (mouth member welded portion) without softening the synthetic resin of the (mouth member end portion), and the preheated mouth member as the bag portion And a welding step of welding the mouth member welded portion and the opening by pressing with a seal mold,
[0012]
[2] The bag making method according to the above [1], wherein the preheating uses radiant heat,
[3] The bag making method according to the above [1] or [2], wherein the length of the end of the mouth member is 0.5 mm or more,
[4] The bag making method according to any one of the above [1] to [3], wherein the end of the mouth member at the time of preheating is not subjected to heat by the heat insulating means,
[5] The bag making method according to any one of the above [1] to [4], wherein in the welding step, welding is performed so as not to heat a range of at least 0.5 mm from the lowermost end portion of the mouth member.
[6] Any one of the above [1] to [5], wherein the mouth member supported by the cylindrical body is inserted into the opening of the bag portion, the bag portion is decompressed, and the mouth member and the bag portion are welded. [7] The above-mentioned problems can be solved by developing a bag-making method according to [7] and a medical container manufactured by the bag-making method according to any one of [1] to [6]. Settled.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
The mouth member 1 serves as a pour-out port for the bag, and the cross-sectional shape is a hollow circle, an ellipse, a rhombus, or a boat. Further, a mouth member having a plurality of outlets in one mouth member may be used.
[0014]
When the cross-sectional shape of the mouth member 1 is circular, the diameter is 10 to 30 mm, the thickness of the mouth member is 0.5 to 3 mm, and the height is about 20 to 80 mm.
Examples of the synthetic resin used for the mouth member include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, and polyolefin resins such as polycarbonate resin, polypropylene, and polyethylene. Among these, polyolefin resins are preferable, and single resins or blend resins of polyethylene resins such as high density polyethylene, linear low density polyethylene, high pressure method low density polyethylene, and polyethylene produced with a metallocene catalyst are particularly preferable. It is preferable to use the same resin as the flexible film constituting the bag portion.
[0015]
Further, the mouth member 1 may be a multi-layered one. In particular, when the outermost layer of the mouth member is made of the same resin as the flexible film, and the innermost layer is made of a resin having higher heat resistance and higher rigidity than the outer layer, deformation of the mouth member during preheating can be further suppressed. In addition, it is also preferable from the viewpoint of suppressing needle penetration from the inside to the outside on the side surface of the mouth member when the injection needle punctures the inside of the mouth member by mistake.
[0016]
The bag portion 2 is made of a flexible film, and examples of the material thereof include polyolefin resins such as polypropylene and polyethylene, polyamide resins, and polyester resins. The same material with a melting point close to the welding surface 12 of the mouth member 1 or those materials can be used. A polyolefin resin obtained by blending these resins is preferred. The flexible film may be either a single layer or a multilayer, and the thickness is about 100 to 400 μm. In the case of a multilayer laminate film, the inner surface of the bag portion may be made of the same material having a melting point approximate to the welding surface of the mouth member or a blended resin containing them. As the flexible film, a cylindrical film manufactured by inflation molding, a film manufactured by T-die molding, or a bag-like one formed by overlapping is used.
[0017]
The welding in the bag making method of the present invention is performed after preheating the mouth member 1 made of a synthetic resin. In most cases, the mouth member 1 is manufactured by injection molding. However, the present inventors have released the confined residual stress generated by the injection molding of the mouth member during preheating and deformed the mouth member. Therefore, when the deformed mouth member 1 is pressed together with the bag portion 2 by the seal mold 5, the contact with the film of the bag portion 2 becomes non-uniform, and the film of the mouth member 1 and the bag portion 2 before welding. Found that there was a local contact and gaps. That is, since the relative positional relationship between the mouth member 1, the bag portion 2, and the seal mold 5 changes due to the deformation of the mouth member 1, the gap between the palm portions cannot be filled with the mouth member resin. Therefore, in order to always make the relative positional relationship of the mouth member 1, the bag part 2, and the seal mold 5 desirable, it is necessary to suppress the deformation of the mouth member 1 at the time of preheating, in order to suppress the deformation. It has been found that it is sufficient to preheat the end 11 of the mouth member without softening. As a result, it has been found that the position adjustment of the mouth member 1, the bag portion 2 and the seal mold 5 can be performed accurately, and welding of the bag portion 2 and the mouth member 1 with no gap between the palm portions can be achieved.
[0018]
Conventionally, in order to weld the mouth member 1 and the bag portion 2, a portion other than the mouth member upper portion 13 to which the rubber plug of the mouth member is attached is used as a mouth member welding portion and heated until the weld portion is softened. In order to suppress the deformation of the member 1, it is possible to prevent heating of the entire mouth member by avoiding heating so as not to soften the mouth portion upper end 13 of the mouth member and the end portion (mouth member end portion) 11 of the mouth member. Deformation is suppressed, the positional accuracy of the mouth member, the bag portion and the seal mold is increased, the adhesion is improved, and a thin piece is formed in the uniform weld and the mouth member weld portion. We have found that welding without gaps can be achieved. In the conventional method, the end portion of the mouth member is also heated, and in some cases, the film is heated to the melting point or more of the film. Therefore, when the mouth member 1 and the bag portion 2 are sealed, the film near the end portion of the mouth member is likely to be thinned. And found that this problem can be solved at the same time. As a result, partial thinning of the film was suppressed, and the bag drop strength of the container body was improved.
[0019]
Here, softening refers to a state in which the surface of the mouth member welded portion pressed through the film by the seal mold is welded to the film and the resin is soft enough to form flakes. It can be seen that the end portion of the mouth member that is not present is in the same surface state as the surface of the mouth member before preheating. In this case, a clear boundary line is seen at the boundary between the mouth member end and the mouth member welded part before being pressed by the seal mold. The object of the present invention is achieved by preheating the mouth member in a state where the boundary line is visually recognized.
[0020]
Preheating is performed by direct heating using a thermal mold, heating using radiant heat using a heat source such as an annular heater or far-infrared rays, and the like. Let temperature be the temperature which the synthetic resin used for the mouth member softens.
Among these heating methods, heating by radiant heat is particularly preferable because it is advantageous in terms of foreign matter adhesion and simplification of the mechanical structure. Moreover, as the preheater 3, it is preferable to use the annular heater of the shape which does not heat the mouth member edge part 11. FIG. 4A and 4B are sectional views showing an example of the mouth member being preheated by the annular heater. Further, the mouth member 1 is fitted in the non-heating portion 34 of the annular heater, or the support is fitted into the hollow portion of the mouth member 1 from above in FIGS. 4 (a) and 4 (b). By supporting the mouth member, the accurate spatial arrangement of the mouth member 1 and the annular heater can be maintained, and the mouth member 1, the preheater 3, and the gap can be maintained with higher accuracy. If the mouth member 1 is further rotated, the amount of heat received from the preheater 3 can be made more uniform over the entire circumference of the mouth member welded portion 12. As a result, the amount of heat received by the mouth member welded portion 12 in the preheating step is stabilized and made uniform, so that the deformation of the mouth member 1 is further suppressed, and the mouth member, bag portion, and seal mold in the next welding step are suppressed. Position adjustment can be performed more accurately.
[0021]
When the mouth member is welded, the heating temperature needs to be a temperature at which a thin piece can be formed on the mouth member when pressed through the film. Although depending on the material of the mouth member, in the case of radiant heat, it can be appropriately selected depending on the distance between the heat source and the surface of the mouth member, the material of the mouth member, etc., but the temperature of the heat source is 500 to 750 ° C. and heated for 8 to 13 seconds. It is preferable. If the temperature of the mouth member welded portion 12 is too high, there is a risk that a synthetic resin degradation product may be generated or fluid deformation may occur. Further, there is a danger that the end temperature of the mouth member is affected by the temperature of the welded part temperature of the mouth member, and this point needs attention.
[0022]
Specifically, in order to soften the mouth member welded portion 12 without softening the mouth member end portion 11, the mouth member end portion 11 is at least 0.5 mm or more, preferably 0, than a heat source such as an annular heater. By projecting 8 mm or more, it is possible to effectively avoid the mouth member end 11 from being softened under the influence of radiant heat. Further, this prevents a reduction in rigidity of the entire mouth member, and can suppress deformation due to heat.
[0023]
As another example, as shown in FIG. 4 (b), a method of using a heat insulating means such as a heat insulating plate 32 for suppressing the radiant heat from the heat source as shown in FIG. For example, there is a method of cooling by contacting a cooling mold having a circular crown-shaped concave portion into which the material enters. Further, as shown in FIGS. 5A and 5B, the length of the mouth member end 11 from the mouth member end lowermost portion 14 is such that the mouth member end 11 is further away from the heat source than the mouth member welded portion 12. The object of the present invention can also be achieved by using a mouth member having a diameter reduced within a range of L of 5 mm or less, preferably 1 to 5 mm.
[0024]
The welding step of pressing and welding the mouth member and the bag portion is a step of inserting the preheated mouth member into the opening portion of the bag portion and pressing it with a seal mold to weld the mouth member welding portion and the opening portion. . Hereinafter, the welding process will be described with reference to FIG. In the following description, an example is shown in which a mouth member supported by a cylindrical body is inserted into a bag portion opening, the bag portion is decompressed, and the mouth member and the bag portion are welded. The decompression method is more effective when the diameter of the mouth member exceeds 10 mm. A similar method is described in US Pat.
[0025]
In order to facilitate the holding of the mouth member, the cylinder 4 is inserted into the hollow portion of the hollow tubular mouth member 1 as shown in FIG.
The cylinder has an outer diameter slightly smaller than the inner diameter of the mouth member, and has a hole penetrating to the tip inside. The tip of the cylinder (air suction port 43) is formed in a shape that fits the bulge of the film in a shape in which the cross-sectional area gradually decreases toward the tip of the cylinder.
The position where the cross-sectional area starts to gradually decrease is 5 mm or more from the end of the cylindrical body and a position ahead of the mouth member end 11. The insertion is made so that the distal end 43 of the cylindrical body protrudes at least 5 mm or more from the end 11 of the mouth member. Moreover, the air in a bag part which will be described later is sucked to reduce the pressure, and the cylinder 4 and the bag are brought into closer contact with each other. Further, if the cylindrical body 4 is also used as a fixing jig for the mouth member 1 in the preheating step, there is an effect of further preventing the mouth member from being deformed. It is necessary to have a mechanical structure that takes into account the difference between the time (the time during which the seal mold is pressed) and the preheating time, which slightly complicates the equipment and increases the cost.
[0026]
If necessary, the air in the bag portion is sucked to reduce the pressure, and the adhesion between the cylinder 4 and the bag 2 is increased. The timing of pressure reduction is performed before the seal mold 5 is tightened or at the same time as the seal mold 5 is closed. Since the bag portion is fixed by reducing the pressure, the film at the boundary between the welded portion and the non-welded portion, which becomes a problem, receives heat from the sealing mold 5 and causes a problem such as a pinhole. Can be suppressed extremely efficiently. In addition, the bag part 2 and the mouth member 1 are strongly brought into close contact with each other, the film is bent and fixed along the shape of the mouth member end part 11, and the mouth member end part is low in temperature, so that the wall thickness is reduced. Is effectively suppressed.
[0027]
The bag part 2 and the mouth member 1 are pressed with a seal mold 5 as shown in FIG. 7 to weld the mouth member weld part 12 and the bag part weld part 21. The temperature of the sealing mold 5 is 10 ° C. or more higher than the melting point of the film (bag portion resin). When the film is made of polyethylene resin, the temperature is 110 to 170 ° C., and the welding time is about 1 to 3 seconds. The shorter the time from the preheating to the pressing by the seal mold 5, the better, but it is usually about 1 to 4 seconds due to the limitation of the manufacturing apparatus. If it exceeds 4 seconds, the surface temperature of the mouth member welded portion tends to decrease, and the sealing strength between the mouth member 1 and the bag portion 2 tends to be insufficient. At this time, if the corner of the mold has a small R as shown in FIG.
[0028]
The shape of the seal mold 5 is composed of a semicircular cross section and a flat portion. Further, R is formed at the connecting portion between the semicircular cross section and the flat portion, and at the palm portion of the mouth member 1 and the film. R is 0.2 to 2 mm, preferably 0.3 to 1.7 mm. If R is too large, the gap between the palms will not be suppressed, and if it is too small, the film will be damaged or the formation of flakes will be insufficient. The diameter of the semicircular cross section is slightly smaller than the diameter of the mouth member welded portion 12 plus the film thickness. In addition, it is preferable to use a sealing mold 5 in which a range of at least 0.5 mm from the lowermost part of the end of the mouth member is welded without heating because it is possible to avoid thinning of the film. Examples of such a sealing mold 5 include a mold whose temperature is adjusted so that the length from the lowermost side of the mouth member end portion is at least 0.5 mm and below the melting point of the film. As a preferable seal mold, there is a mold in which the mouth member 1 is projected from the seal mold 5 by a length M as shown in FIG. The length M is preferably 0.5 mm or more. According to this, the film is not pressed between the tip of the mouth member and the mold, and it is difficult for the film to be thinned.
In the above example, the bag part is decompressed and the mouth member and the bag part are welded, but the mouth of the mouth member 1 and the bag part 2 is not softened without softening the mouth member end part 11 during the preheating. By forming the member welding part 12 so as to be softened, the effect of the present invention can be achieved by pressing the mouth member 1 and the bag part 2 without using the cylindrical body.
[0029]
The mouth member 1 heated in the preheating step of the present invention is prevented from being deformed due to the elimination of residual stress during injection molding, and the mouth member 1 and the bag portion 2 are inserted into the seal mold 5 at accurate positions. can do. In addition, since welding is performed in such a precisely positioned state, the softened resin of the mouth member welded portion 12 pressed by the flexible film becomes a thin piece having a stable shape and extends in the gap portion of the palm portion. The
[0030]
A suitable size of the flakes is about 50 to 200 μm in thickness and about 0.1 to 2 mm in length. According to the present invention, it becomes a mouth member having a thin piece of such a size, and by welding this, it is possible to stably produce a bag with a mouth member that does not cause a gap between the palms and does not leak. it can.
[0031]
When the mouth member is welded, the welded portion is held with a cooling mold. As is the case with both the cooling mold and the sealing mold, the positioning of the mold and the object to be held is controlled because the deformation of the mouth member during preheating is suppressed. Can be performed accurately and stably, and the flakes are stably formed.
[0032]
If the pressure has been reduced, release the pressure reduction. By performing welding under reduced pressure and cooling, the film is welded with a mouth seal and a film seal mold, and the film is fixed in close contact with the shape of the nozzle until cooled. By performing welding in such a state that the free movement of the film is suppressed, the melted and softened film is not stretched, and the film thickness is reduced at the boundary between the mouth member welded portion and the unwelded portion. There is an effect to be suppressed.
[0033]
【Example】
A mouth member made of an equivalent blend composition of high-density polyethylene and linear low-density polyethylene having a circular cross-sectional shape and a diameter of 17 mm, an inner diameter of 13 mm, a mouth member welded portion and a thickness of 2 mm at the end portion was manufactured by injection molding. .
A tubular linear low-density polyethylene film having a width of 140 mm was formed by an inflation molding method, cut into a length of 300 mm, one cut portion was closed by heat sealing, and the other cut portion was used as a mouth welded portion. On the other hand, an annular heater having a radiant portion surface temperature of 700 ° C. with an end of the mouth member protruding 1 mm from the radiant portion is inserted into the center of the mouth member, heated for 10 seconds, and then inserted into a hollow cylinder. Immediately insert it into the welded part of the bag, suck it with a vacuum pump to reduce the pressure inside the bag, and at the same time sandwich it with a sealing mold set at 140 ° C for 2 seconds, then sandwich it with a cooling mold for 3 seconds and release the vacuum. The hollow cylinder was pulled out to produce a bag with an opening member.
[0034]
100 bags with mouth members, filled with 500 mL of water and sealed, were pressed from the outside so that the internal pressure was 0.07 MPa and left for 5 minutes. No water leakage was observed in all the bags with mouth members.
[0035]
【The invention's effect】
The bag-making method of the present invention has few steps and can stably suppress the occurrence of a gap at the palm portion, so that liquid leakage from the bag with the mouth member can be suppressed, and further, the heating of the tip of the mouth member can be performed. Since it is possible to prevent thinning of the film forming the resulting bag portion, it can be used and useful in fields such as medical containers.
[Brief description of the drawings]
FIG. 1 is a perspective view of an example of a mouth member. FIG. 2 is a cross-sectional view of a palm portion having a gap. FIG. 3 is a cross-sectional view of a palm portion using a mouth member having a thin piece. ) Cross-sectional view during preheating of mouth member welded portion with annular heater (b) Cross-sectional view of preheated mouth member welded portion with annular heater (c) (a) AA in cross-sectional view Cross-sectional view [FIG. 5] (a) Perspective view of another example of mouth member (b) Cross-sectional view of another example of mouth member [FIG. 6] Cross-sectional view when decompressing mouth member and bag portion [FIG. ) Seal mold cross-sectional view (b) Partial enlarged view of (a) [Figure 8] Seal mold vertical cross-sectional view [Explanation of symbols]
1 mouth member 11 mouth member end portion 12 mouth member welded portion 13 mouth member upper portion 14 mouth member end portion lowermost portion 2 bag portion 21 bag portion welded portion 22 gap at the palm portion 23 flake 3 preheater 31 heater 32 heat insulating plate 33 heat insulating material 34 Non-heating part 4 Cylindrical body 41 Cylindrical support part 42 Depressurization port 43 Air suction port 5 Seal mold 6 Medical container

Claims (7)

A bag-making method in which a mouth member made of a preheated synthetic resin and a bag portion made of a flexible film are welded and integrated, and the end of the mouth member on the bag side during the preheating (the mouth member) A preheating step of softening the synthetic resin of the welded portion (mouth member welded portion) between the mouth member and the bag portion without softening the synthetic resin at the end portion, and the preheated mouth member at the opening of the bag portion And a welding step of welding the mouth member welded portion and the opening by pressing with a seal mold. The bag making method according to claim 1, wherein the preheating uses radiant heat. The bag making method according to claim 1 or 2, wherein the length of the end of the mouth member is 0.5 mm or more. The bag making method according to any one of claims 1 to 3, wherein the end of the mouth member at the time of preliminary heating is prevented from receiving heat by the heat insulating means. The bag making method according to any one of claims 1 to 4, wherein, in the welding step, welding is performed so as not to heat a range of at least 0.5 mm from the lowermost part of the end of the mouth member. 6. The bag making method according to claim 1, wherein the mouth member supported by the cylindrical body is inserted into the opening of the bag portion, and the bag portion is decompressed to weld the mouth member and the bag portion. . A medical container manufactured by the bag making method according to any one of claims 1 to 6.

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