JPH0624573B2 - Infusion solution bag, its manufacturing method and molding die - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an infusion bag, a method for manufacturing the same, and a mold for forming the same. More specifically, when the content liquid is drained, the periphery of the container is flatly crushed. An attempt is made to obtain an infusion bag to be obtained, a manufacturing method thereof, and a molding die.

<Problems to be Solved by Conventional Techniques and Inventions> Conventionally, as one of the methods for producing an infusion bag, a plastic parison is extruded and hung down in a mold to blow the parison along a mold hole. There is a blow molding method.

As a feature of this method, it has the advantage that it can be mass-produced, etc., while the mold used has a rounded rounded shape corresponding to the shoulder part and the peripheral part of the bag. There is a drawback that the shape of the shoulder portion and the peripheral portion of the bag is necessarily rounded. The reason for this is that it was feared that if the shape of the above-mentioned part of the mold was made rectangular, the resin thickness of that part would be thin. However, if the infusion bag is formed into a round shape, the infusion bag remains flat without being flatly crushed even when completely drained. If the rounded shape remains, it becomes difficult for the volume surfaces to come into close contact with each other, which prevents flat collapse. Therefore, it becomes difficult to completely discharge the inner solution at a stable speed.

Therefore, in order to solve the above-mentioned problems, conventionally, the side peripheral edge portion (20) and the lower peripheral edge portion (3) of the molded infusion bag (1 ′) are formed.
After heat-sealing the rounded part of (0), trimming (C)
Then, the rounded portion was removed by (C) (see FIGS. 15 and 16; see, for example, JP-A-61-287728).

However, in the manufacturing process, a heat-sealing process after molding is required, and since many parts are removed, the resin is wasted.

This invention, in an infusion bag manufactured by blow molding, without injecting heat-sealing the rounded portion, the infusion bag in which the shape of the shoulder portion and the peripheral portion of the infusion bag is formed into a shape suitable for bag crushing, and An attempt is made to provide a manufacturing method and a molding die.

<Means for Solving the Problems> As a structure of an infusion bag for achieving the above-mentioned object, a synthetic resin infusion bag manufactured by blow molding, in which the shape of a shoulder portion and a peripheral portion of the bag is an acute angle or It is characterized in that it is formed into a substantially flat rectangular shape and the entire bag is blow-molded as one piece.

Then, as an invention method for achieving the above object,
The mold corresponding to the shoulder portion and the peripheral portion of the bag has an acute angle or a substantially flat rectangular shape, and a parison made of a synthetic resin is extruded and hung down while the mold is positioned outside the acute angle or substantially flat rectangular shape. It is characterized in that the parison is blow-molded along the shape of the mold cavity with a slight gap left on the mating surface.

Furthermore, as a molding die for achieving the above object,
Partial shape of the mold corresponding to the shoulder portion and the peripheral portion of the bag is an acute angle or a substantially flat rectangular shape, and a pinch portion that provides a slight gap is provided on the mating surface of the mold. To do.

<Operation> When the shoulder portion and the peripheral edge portion have an acute angle or a substantially flat rectangular shape as described above, the infusion bag is crushed into a flat and low bulk state as the content liquid is discharged, and the liquid is stabilized. It enables complete discharge at the specified rate.

Further, according to the manufacturing method and the molding die described above, it is possible to mold the shape of the shoulder portion and the peripheral portion of the infusion bag into an acute angle or a substantially oblate shape that is easy to crush.

<Example> Next, an example of the present invention will be described below with reference to the drawings.

In FIG. 1, (1) shows the whole of the infusion bag, (2) is a lateral peripheral portion, (3) is a lower peripheral portion, (4) is a shoulder portion,
(5) shows an infusion port, and (6) shows a hole or notch for suspension.

The peripheral edge portion (2), the lower peripheral edge portion (3) and the shoulder portion (4) are formed to have an acute angle as shown in FIGS. 2 and 3 or a substantially flat rectangular shape as shown in FIGS. 4 and 5. The shape of the entire infusion bag is integrally formed as shown in the figure.

Next, FIGS. 6 to 8 show a mold device for manufacturing the infusion bag (1) having the above-described shape, and (10) and (10 ') are divided molds for molding. The molds (10) and (10 ') are shaped so that the parison (P) made of plastic is extruded and hung down, and is blown with air to conform to the internal shape. The molds (10) and (10 ') are formed with acute-angled partial shapes corresponding to the side peripheral edge (2), the lower peripheral edge (3) and the shoulder (4) of the infusion bag (1). (11) (12) is the mold (10) (10 ')
The pinch part where a gap can be formed is shown.

To mold the infusion bag (1) using the above molds (10) (10 '), put the parison (P) made of synthetic resin into the mold with the molds (10) (10') open. And hang it down, while closing the mold, squeeze the part that will be the infusion bag mouth (5) and mold (10).
While closing the mold so that there is a slight gap at the pinch parts (11) and (12) on the mating surface of (10 '), parison (P)
While blowing air into the mold to expand it, the parison is placed inside the mold.
Along with (P), mold the infusion bag (1). Then open the mold.

At the time of the above-mentioned molding, the side peripheral edge portion (2), the lower peripheral edge portion (3) and the shoulder portion (4) of the infusion solution bag (1) are molded into an acute-angled shape with the partial shape of the mold.

Further, instead of the acute-angled partial shape of the mold (10) (10 '),
You may implement | achieve by forming it in a substantially oblong shape like FIG. 9 and FIG.

Furthermore, the shape shown in FIG. 11 and FIG. 12 can be adopted.

A particularly preferable shape of the mold is that shown in FIG.

In the mold of the present invention, the angle of the portion corresponding to the peripheral portion of the bag and the shoulder portion is in the range of about 10 ° to about 80 °. If the angle is smaller than this, defects due to adhesion of the parison are likely to occur, and if larger than this, the flatness of the molded bag is impaired.

As the parison (P), it is preferable to use a tubular or flat cylindrical tubular parison in general blow molding, but sheet blow molding can also be performed using a pair of two sheet parisons.

When a tubular parison is used, it is preferable that its diameter (width) is thicker than the conventional one, and it is about 0.5 to 1.3 times, preferably about 1.1 times the mold cavity. Carry out things.

In the case of a parison (P) whose width is 1.0 to 1.3 times as wide as the mold hole, use the same thickness as that of the molded product after molding, 0.5 to 1.
When using a parison having a width of 0 times, it is preferable to use a parison that is slightly thicker than the molded product after molding. The tubular parison does not have to have a bottom, but when the diameter of the parison die is small, it must be inflated so that the diameter of the parison falls within the above range.

On the other hand, when the sheet blow molding is performed, the thickness of the sheet parison is approximately the same as that of the molded product.

Various synthetic resins applied to a general blow molding method can be used for manufacturing the infusion bag of the present invention, but a polyolefin resin is preferable. Among them, low density polyethylene and polypropylene are particularly preferable.

<Effects> According to the above-mentioned infusion solution bag of the present invention, the shoulder portion and the peripheral edge portion are not formed in a round shape but in an acute angle or a substantially flat rectangular shape, and the entire bag is integrally formed. Therefore, it will be flattened.

Further, according to the manufacturing method of the present invention, the heat sealing step as in the case of the rounded shape is unnecessary, the number of steps is small, and the trimming is not necessary or the number of parts is very small, which facilitates the manufacturing.

Furthermore, since the molding die of the present invention is also provided with a pinch portion with a slight gap on the mating surface of the die, the shape of the shoulder portion and the peripheral portion of the bag is blow-molded into an acute angle or a substantially flat rectangular shape. It is easier to do, and it is not necessary to use a mold hole larger than the molded product as in the past, but it is sufficient to use a mold hole of almost the same size as the molded product, so the mold body can be downsized and the economic advantage is great. become.

[Brief description of drawings]

1 is a front view of an infusion bag manufactured according to the present invention, and FIGS. 2 and 3 are FIGS. 1 II-II and III-III.
4 and 5 are cross-sectional views of modified shape examples,
FIG. 6 is a schematic perspective view of the mold, and FIGS. 7 and 8 are schematic perspective views.
VII-VII and VIII-VIII enlarged sectional views, FIG. 9 and FIG. 10 and FIG. 11 and FIG. 12 are enlarged sectional views of the shape modification example, and FIG. VII-VII is an enlarged cross-sectional view at the same place as FIG. 14, FIG. 14 is a cross-sectional view at the same place as III-III of the infusion bag manufactured by the mold of FIG.
FIG. 16 and FIG. 16 are schematic views showing a conventional example of forming the side peripheral edge portion and the lower peripheral edge portion. (1) …… infusion bag, (2) …… side peripheral edge, (3) …… lower peripheral edge, (4) …… shoulder, (5) …… infusion port, (P) …… parison, (10) (10 ′) …… Mold.

Claims (3)

[Claims] 1. An infusion bag made of synthetic resin produced by blow molding, wherein the shape of the shoulder portion and the peripheral portion of the bag is formed into an acute angle or a substantially oblate shape, and the entire bag is integrally blow molded. An infusion bag characterized in that. 2. A parison made of a synthetic resin is extruded and hung down from a mold whose partial shape corresponding to the shoulder portion and the peripheral edge portion of the bag is an acute angle or a substantially flat rectangular shape, and the parison made of the synthetic resin is drooped down from the acute angle or substantially flat rectangular shape. A method for producing an infusion bag, which comprises blow-molding a parison along a mold hole shape with a slight gap being provided outside on a mating surface of a mold. 3. A bag having a shoulder portion and a peripheral portion corresponding to a peripheral portion of the mold having an acute angle or a substantially flat rectangular shape, and a pinch portion provided with a slight gap on a mating surface of the mold. A blow molding die for an infusion bag, which is characterized in that