Title:
Arrangement for bags especially for infusion and procedure for their production
Technical field:
The present invention relates to an arrangement for bags especially for infusion and made from at least two layers of plastic foil which are welded together along a continuous weld seam so. that a space is formed for a liquid, especially for infusion purposes, the said liquid space being arranged so that via one or more connection points it is connected to further arrangements such as a filling arrangement for filling it with liquid, a drain tube, an injection needle or the like, and where at least one connection point is designed as a channel section with firstly an inner connecting member for the liquid space in the bag, the said member comprising a pierc able parting wall located at some distance from the far end of the channel section and secondly an external connecting member which is designed to seal off the channel section also outside the said piercable parting wall and to be opened to permit the introduction of some of the said external arrangements through the outer end and through the pierc-able separating wall.
The present invention relates also to a method for manufacture in accordance with the preamble to patent claim 8.
Technical problem:
In order to supply certain, substances to the body infusion, known as "drip", is eaployed and with the technique envisaged here the substance is supplied whilst enclosed in a plastic bag to which a tube is connected through which the substance can be supplied to the patient. With previously known bags a special inlet is provided through which the substance can be poured in. and which is sealed directly after filling, together with one or more separate openable outlets for emptying the bag via the said tube. Furthermore it is customary to provide the bag with an entry point for medicaments which are to be injected using a hypodermic syringe. This entry point is usually formed by a pierc able plug which as a result of its elasticity seals itself after the hypodermic syringe is withdrawn.
The aim of the present invention is to rationalise the manufac
ture of infusion bags and to reduce production costs by reducing the number of connection points to the bag interior.
The solution:
The said objective is achieved by means of an arrangement in accordance with the present invention which is characterised in that the said piercable separating wall forms part of a separate connection plug, that the sealing plug and the said outer connecting members are arranged to be inserted in the said channel section only after the liquid has been poured in, that the said channel section is open during one filling stage and serves as inlet for liquid to the said liquid space and subsequently in an emptying stage functions as outlet after opening of the outer connecting member and piercing of the wall of the sealing plug by some of the said external arrangements.
The said objective is also achieved by means of a procedure in accordance with the present invention which is characterised in that the said channel section is provided, during the production of the bag, with a completely open through cavity, that the said channel section in one filling stage is employed as inlet and connected to the said filling arrangement, whereby liquid is poured in, and that a sealing plug having the said piercable separating wall is inserted in the said channel section, that the external sealing member is connected to the outer end of the channel section, as a result of which the filled bag is kept sealed until during an emptying stage the liquid space in the bag is made accessible by the opening of the outer sealing member and piercing of the piercable separating wall.
Brief description of drawings:
In the following the invention will be described in greater detail by means of several embodiments and with reference to the appended diagrams in which fig. 1 shows a partially broken view of an infusion bag in accordance with the invention, fig. 2 provides a partially broken side view of the bag, fig. 3 shows a view from the front of a connecting piece forming part of the bag having a sealing foil which seals off the connecting piece, fig. 4 shows a view of the connecting piece with an associated sealing plug prior to its assembly in the connection piece, fig. 5 gives a side view of the connecting piece illustrated in fig.4 with the sealing plug assembled in position and
fig. 6 shows the said sealing foil separately. Fig. 7 gives a partially broken view of the bag in a second embodiment, fig. 8 illustrates the separate connection piece in accordance with the second embodiment of the bag with associated sealing plug prior to its assembly, fig. 9 shows a variation of the bag in accordance with the invention, the view corresponding essentially with that in fig. 1, fig. 10 is a view from the front of the variant as in fig. 9, and fig. 11 shows an exploded view of a separate channel section forming part of the arrangement in accordance with the invention.
Best mode of carrying out the invention:
As shown in fig. 1, an Infusion bag 1 is formed by two plastic foils, made for example fromplasticised polyvinyl chloride or a tube shaped plastic foil which is welded together along a weld seam 3, so that two plastic foil layers are formed which are not connected with each other in a centre area so that a space 4 is formed for the bag contents. The contents can for example be glucose or blood. The edge portions at the ends are welded with double weld areas so that broader sections are formed for the attachment of supplementary items such as corner zones so as to facilitate the handling of the bag, holes 7 for hanging up the bag during its emptying stage, and a moulded connecting piece 8.
The connecting piece 8 has two connections in the form of two tubular channel sections, a first channel section 16 with a cavity 17 and a second channel section 18 with a cavity 19. The two channel sections 16, 18 are united by means of a platform-like connecting portion 20 which holds the channel portions together so that these together with the connecting portion and a flange portion 21 which extends in front of the channel portions, form one piece of material. This is made in a somewhat more rigid material than the remaining portions of the bag and is for example made from unplasticised polyvinyl chloride. The inner tubular ends 22 of both channel portions 16, 18 extend for some distance inside the liquid space 4 of the bag.
As shown in fig. 3 the outer ends 23, 24 of both channel portions 16, 18 are sealed by a sealing foil 25 of plastic film, e.g. plasticised polyvinyl chloride. The sealing foil covers the whole of the flange portion 21 which is common to the entire connecting piece 8 and extends beyond both ends of the flange portion by way of two tab
sections 26. These are provided with fluted portions 27 so as to provide a safe grip for the user. Furtheroore the sealing foil 25 has two V-shaped tear initiation points 28 facing each other, as also indicated in fig. 6, where the sealing foil 25 is shown separately prior to its attachment to the flange portion 21. As indicated in fig. 3 the sealing foil 25 has become somewhat deformed during attachment to the flange portion. The sealing foil 25 is welded firmly to the flange portion 21 by high-frequency welding, the sealing foil being connected with the flange portion by means of a "half weld seam" 29 which runs in the manner shown in fig. 3 and extends along both long edge portions 30, 31 of the flange portion and beyond the outer ends 23 of both channel portions 16, 18. Thus the half veld seam 29 proceeds around both ends of the channel portions, thereby sealing these. The half weld seam 29 is not completely welded to the flange along its entire length, but instead is more or less "spot welded" along a plurality of smaller areas,arranged at intervals, as shown in fig.3- Between these areas the foil is not completely welded to the flange but does adhere to this, but in such a way that a liquid-tight and high-quality sterile seal of both channel portions 16, 18 is obtained.This type of weld facilitates the tearing off of both portions of the sealing foil 25 which are located beyond the tear initiation lines 28. However in a central veld zone 32 full welding is undertaken so as to completely separate the outer ends 23, 24 of both channel portions 16, 18 from each other.
In accordance with the invention there is no separate connection for filling the liquid space 4 of the bag with liquid. This filling is usually carried out in conjunction with manufacture of the bag, and in accordance with the present invention is carried out through one of the two channel portions 16, 18 which are also provided for emptying the liquid contents of the bag. This has been rendered possible in that this channel portion l6 has been made somewhat larger in size than is necessary for emptying, and because the channel portion 16 is so designed that the cavity 17 is originally made so that it is absolutely continuous and by this means can be kept fully open during a filling stage, after which the sealing of the channel portion l6 is undertaken by means of a separate sealing plug 33, an initial embodiment of which is shown in fig. 1 - 5. The
sealing plug is provided with a cylindrical, tube-shaped portion 34, the external diameter of which corresponds essentially with, or is somewhat less than, the internal diameter of the cavity 17 in channel portion 16. Furthermore the sealing plug 33 has a bottom membrane
35 which forms the inner seal conventionally employed with infusion bags and which is designed to be pierced by means of a hypodermic needle or the like when connecting up the tube through which the contents of the bag are to be emptied. The sealing plug 33 in accordance with the first embodiment furthermore is provided with a collar
36 at its top, which fits into a corresponding shoulder 37 in the flange portion 21 of the connecting piece as shown in fig. 4 and 5. The welding in position of the sealing plug 33 is achieved by weld ing the collar 36 in the said shoulder 37 in the flange portion 21 , which hence takes place after the liquid space 4 in the bag has been filled through the open, continuous cavity 17 in channel portion 16. After this the final sealing of the bag takes place by welding the sealing foil 25 against the flange portion 21.
As shown by the diagrams the second channel portion 18 similarly has a membrane 38 in cavity 19 located at a distance from the outer end 23 of the cavity. However this membrane 38 can be arranged per manently in a conventional manner. As shown by fig. 1 , in front of this membrane 38 a plug 39 is inserted made of an elastic material such as rubber or the like. This plug 39 is intended to ensure self sealing after a hypodermic syringe has been introduced into the channel portion 18. This connecting point which is formed by channel portion 18 is for example designed for the supply of medicaments by means of a hypodermic syringe or the like. Furthermore a ring-shaped portion 40 having a channel 41 is inserted in front of plug 39 and forms a guide for the inserted tip of the hypodermic syringe so that this is introduced in a fairly straight manner through the cavity 19 of channel portion 18. As shown in fig. 5 the inner, inwardlyprojecting, ends 22 of both channel sections have recesses 42, more particularly two recesses for each channel portion. These recesses 42 extend from the inner ends 22 of the channel portions up to the edge portion 43 of the liquid space formed by the weld seam 3 which encloses the liquid space 4. Because the two channel sections 16, 18 project inwardly for some distance into the liquid space 4, this prevents the tip of an inserted hypodermic needle from accidentally
piercing a hole in the plastic foil 2, whilst at the same time the recesses 42 ensure that the liquid contents can be emptied completely through the connections. In addition the recesses 42 impart flexibility to the inwardly projecting ends 22 so that a smooth transition is obtained from the thicker connecting piece 8 to the thinner liquid space 4, as indicated by fig. 2.
A leak-proof seal around the connecting piece 8 is obtained by welding the two layers of plastic foil 2 to the connecting piece on both sides of the latter, firstly across a weld zone 44 which connects the layer of plastic foil with the connecting section 20 and secondly along a weld seam 45 which extends around the outside of each of the two channel sections 16, 18 on either side of the connecting piece, the weld seas 45 connecting up with weld seam 3 which proceeds around the liquid space 4.
Fig. 7 and 8 illustrate a second embodiment of the invention where the sealing plug, which in this example is designated as 46, is designed without a collar. Otherwise, in this example also the sealing plug has a tubular cylindrical portion 47 and bottom membrane 48. Instead of the collar, the cavity 17 of the channel portion is provided with a stage-wise reduction in diameter in the direction into the bag, so that a shoulder 49 is formed inside the cavity 17 against which the base of the sealing plug 46 can rest so as to keep the sealing plug in position. Thus in this example there is no shoulder on the flange portion 21.
In principle the procedure for filling the bag and sealing it are the same as with the first embodiment, but the welding in position of the sealing plug takes place around the cylindrical tubular portion 47 and at the same position as the weld seas 45 which welds the two layers of plastic foil 2 around the channel portion 16. However these two fixing welds are made at different times, weld seam 45 being provided at an early stage during the manufacture of the actual bag, whilst the welding in position of sealing plug 46 takes place after liquid has been filled into the bag. This can take place at a later station on one and the same machine which has several operating stations, where first of all the bag is made, then liquid is filled in and after this the sealing plug is applied and welded in position, which is followed by the welding of the sealing foil 25. However it can be advantageous that the main operation of producing
the bag takes place on one machine, whilst filling with liquid, welding of the sealing plug and sealing foil in position take place on separate mechanical equipment.
To ensure a high degree of sterility and minimum risk of contamination at the connection points, there are thus two sealing members in each connection, firstly the inner membrane 35, 38, 48 and secondly the outer sealing foil 25. Between these two sealing positions a chamber is formed in each cavity 17, 19 in both channel portions 16, 18, which are designated as expansion chambers 50 so as to form room for expansion during the sterilisation, known as autoclaving, of the infusion bag, during which the bag is subjected to relatively high temperatures. Hence with the arrangement in accordance with the present invention this expansion chamber is formed by the cavity 51 which is present in the sealing plug 33, 46 and is thus confined by its bottom membrane 35 in the base of the plug and by the welded on sealing foil. By means of the arrangement in accordance with the invention one of the connections to the infusion bag 1 thus has two main functions, which functions are utilised during two different stages of bag use, namely first of all a filling stage when the connection, i.e. the channel portion 16, is used for filling of liquid before any sealing member is applied, and secondly an emptying stage after the sealing member has been pierced or removed, when the connection is employed for draining off the liquid. This consequently simplifies bag design and manufacture in that the sealing of the connection is combined with the provision of the requisite membrane in the connection.
Fig. 9, 10 and 11 illustrate a variation of the bag in accordance with the invention. In accordance with this variation there is no integral connecting piece for the two channel portions 51, 52, these instead being designed as separate units which are connected in leakproof fashion between the two layers of plastic foil of the bag 1 by means of weld seams 53, 54 on either side of each channel portion wall. The channel portions 51, 52 comprise essentially cylindrical units with an inner, open end 55 and with an outer end 67 which, prior to use, is sealed by means of the tear-off sealing foil 56, This is connected to a flange portion 57 which is arranged separately for each channel portion. Hence two sealing foils are provided and each is welded to its flange portion 57 and each has a tab portion 58 which
is provided with a grip portion 59 so as to facilitate tearing off. As shown mainly by fig. 9, both channel portions 51, 52 hare an insertable sealing plug 60 with bottom membrane 61. The sealing plugs are of the type illustrated in fig. 7 and 8, i.e. they do not have their own flange and are inserted in a portion of the cavity 62, 63 of the channel portions which is enlarged by a shoulder.
Fig, 10 shows best the arrangement of the sealing foils 56 which are welded onto the flange portion 57 by an annular weld which surrounds the outer end 67 of the channel portions 51, 52 so that the cavities of the channel portions are protected against contamination before the bag is used. The sealing foils are attached in such a way that the portion which covers the outer apertures of the cavities 62, 63 is opened up when the sealing foils are torn off. This is possible because these are welded against the flange portions 57 by means for example of a "half weld seam" so that the foils are released from the flange portions without the risk that only the tab portions 58 are torn off. It is also possible to provide here tongue-shaped tear initiation points which surround the outer ends 67 of the cavities.
In fig. 11 an exploded view shows one channel portion 52. This view, also fig. 9, illustrates that the sealing plug 60 has a further plug 64 made of an elastic material such as rubber or the like. This plug corresponds to the elastic plug described in conjunction with fig. 1 and ensures self-sealing after a hypodermic syringe is introduced into the channel portion. Furthermore in front of the elastic plug 64 an annular portion 65 is provided having a channel 66 which forms a guide for an inserted hypodermic needle tip so that this can be introduced fairly straight into and through, the cavity 63 of the channel portion 52.
Because both channel portions 51 , 52 are provided with sealing plugs 60 with bottommembranes 61 , either of the two channel portions can be employed for pouring in liquid, because filling takes place prior to attachment of the respective plug with bottom membrane. In addition a simplification from the production viewpoint is obtained in that the channel portion can be manufactured with a through cavity right from the outset. The provision of channel portions in separate units, separated from each other, furthermore provides a production simplification and savings in material.
The invention is not restricted to the embodiments described above and illustrated on the drawings, but can be varied within the framework of the following patent claims. For example the sealing plugs can be designed in a different way. Instead of members resembling shoulders which hold the plug in position before this is welded home, the sealing plug can be made slightly tapered, the cavity of the channel portion also being made slightly tapered at the corresponding location so as to form a seat for the sealing plug. Furthermore it is not absolutely essential that the membrane be located at the base of the plug, as this can be located somewhere inside the cylindrical portion of the sealing plug. The number of connections can vary, dependent on the purpose of the bag. For example it is feasible that there be only one connection, which thus serves to some extent as an inlet for filling the bag and also as an outlet for emptying the bag. The number of connections can be either three or more.