U.S. patent application number 09/980227 was filed with the patent office on 2002-08-22 for moulding suitable for pharmaceutical applications and method for production thereof.
Invention is credited to Claessens, Albert Louis Victor Jozef.
Application Number | 20020113033 09/980227 |
Document ID | / |
Family ID | 26005198 |
Filed Date | 2002-08-22 |
United States Patent
Application |
20020113033 |
Kind Code |
A1 |
Claessens, Albert Louis Victor
Jozef |
August 22, 2002 |
Moulding suitable for pharmaceutical applications and method for
production thereof
Abstract
The invention relates to a moulding serving for pharmaceutical
uses, such as a stopper (1) for pharmaceutical bottles, a
protective cap (2) for medical syringes or a sealing element (38,
39) for pharmaceutical containers, and proposes, to achieve
production with virtually no scrap and with high product quality,
that the moulding (1, 2, 38, 39, 44) consists, at least in a
subregion, of a thermoplastic elastomer material with a mineral
filler content of 30% or more and this subregion has a hot-runner
injection point which is formed as a smooth-surfaced mark.
Inventors: |
Claessens, Albert Louis Victor
Jozef; (Houthalen, BE) |
Correspondence
Address: |
Martin A Farber
Suite 473
866 United Nations Plaza
New York
NY
10017
US
|
Family ID: |
26005198 |
Appl. No.: |
09/980227 |
Filed: |
March 25, 2002 |
PCT Filed: |
April 5, 2001 |
PCT NO: |
PCT/EPO1/03891 |
Current U.S.
Class: |
215/355 |
Current CPC
Class: |
B65D 51/002 20130101;
B29C 45/0013 20130101; B29L 2031/565 20130101; B29C 45/16 20130101;
B29K 2221/003 20130101 |
Class at
Publication: |
215/355 |
International
Class: |
B65D 039/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 6, 2000 |
DE |
100 16 961.9 |
Mar 10, 2001 |
DE |
101 11 550.4 |
Claims
1. Moulding serving for pharmaceutical uses, such as a stopper (1)
for pharmaceutical bottles, a protective cap (2) for medical
syringes or a sealing element (38, 39) for pharmaceutical
containers, the moulding (1, 2, 38, 39, 44) consisting, at least in
a subregion, of a thermoplastic elastomer material with a mineral
filler content of 30% or more and this subregion having a
hot-runner injection point which is formed as a smooth-surfaced
mark.
2. Moulding serving for pharmaceutical uses, such as a stopper (1)
for pharmaceutical bottles, a protective cap (2) for medical
syringes or a sealing element (38, 39) for pharmaceutical
containers, the moulding (1, 2, 38, 39, 44) consisting, in a
subregion, of a thermoplastic elastomer material with a mineral
filler content of 30% or more and this subregion having an
injection point, which is injected over by a second part of the
moulding, consisting of another plastics.
3. Moulding according to claim 2 or in particular according
thereto, characterized in that the injection point of the subregion
formed from the flexible elastomer material is formed as a
hot-runner injection point.
4. Moulding according to claim 3 or in particular according
thereto, characterized in that the hot-runner injection point is
formed as a smooth-surfaced mark.
5. Moulding according to claim 1 or in particular according
thereto, characterized in that the moulding altogether consists of
the elastomer material.
6. Moulding according to one or more of the preceding claims or in
particular according thereto, characterized in that the hot-runner
injection point goes over into the surrounding moulding wall
without being offset outwards.
7. Moulding according to one or more of the preceding claims or in
particular according thereto, characterized in that a hot-runner
injection point offset outwards with respect to the surrounding
moulding wall is encapsulated by a plastics part.
8. Moulding according to one or more of the preceding claims or in
particular according thereto, that the smooth-surfaced mark of the
hot-runner injection point goes over into the moulding wall
surrounding it in a co-planar manner.
9. Moulding according to one or more of the preceding claims or in
particular according thereto, characterized in that the moulding is
of a predominantly thick-walled form.
10. Moulding according to one or more of the preceding claims or in
particular according thereto, characterized in that, in the case of
the stopper (1), a stopper top (13) and a stopper collar (14) are
formed and in that there is a central hot-runner injection (A) in
the region of the stopper top (13).
11. Moulding according to one or more of the preceding claims or in
particular according thereto, characterized in that, in the case of
the stopper, the stopper top (13) has a central region (12) of
smaller wall thickness (x) and an edge region (15) of greater wall
thickness (y).
12. Moulding according to one or more of the preceding claims or in
particular according thereto, characterized in that it takes the
form of a protective cap (2) for medical syringes and in that the
protective cap (2) has a hot-runner injection (A) in the region of
the cap hat (18).
13. Moulding according to one of more of the preceding claims or in
particular according thereto, characterized in that the
thermoplastic elastomer material contains a proportion of
plasticizers.
14. Moulding according to one or more of the preceding claims or in
particular according thereto, characterized by being formed as a
sealing element for a pharmaceutical bottle, a central hot-runner
injection (A) being provided in an outer surface.
15. Moulding according to one or more of the preceding claims or in
particular according thereto, characterized in that, in the case of
a stopper, the stopper collar (14) has a greater wall thickness (z)
than the stopper top (13) in its central region.
16. Protective cap (2) produced in the plastics injection-moulding
process for medical syringes, with a solid cap hat (18) and a
comparatively thin-walled cap neck (19), characterized in that the
protective cap (2) consists of thermoplastic elastomer material
with a mineral filler content of 30% or more and in that there is a
hot-runner injection (A) in the region of the cap hat (18).
17. Protective cap according to claim 16 or in particular according
thereto, characterized in that the thermoplastic elastomer material
contains a proportion of plasticizer.
18. Protective cap according to claim 16 or 17 or in particular
according thereto, characterized in that a central hot-runner
injection (A) is performed in the region of the tip of the cap
hat.
19. Method for producing a moulding for a pharmaceutical use, such
as a stopper (1) for pharmaceutical bottles, a protective cap (2)
for medical syringes or a sealing element (38, 39) for
pharmaceutical containers, characterized in that the moulding is
produced, at least in a subregion, from a thermoplastic elastomer
material with a mineral filler content of 30% or more and this
subregion is configured by a hot-runner injection, the injection
point being formed as a smooth-surfaced mark.
20. Method for producing a moulding for a pharmaceutical use, such
as a stopper (1) for pharmaceutical bottles, a protective cap (2)
for medical syringes or a sealing element (38, 39) for
pharmaceutical containers, characterized in that the moulding is
produced, in a subregion, from a thermoplastic elastomer material
with a mineral filler content of 30% or more and this subregion is
configured by an injection having an injection point, which
injection point is injected over with another plastics, forming a
second subregion of the moulding.
21. Method according to claim 20 or in particular according
thereto, characterized in that the injection of the thermoplastic
elastomer material is carried out by a hot-runner injection.
22. Method according to claim 21 or in particular according
thereto, characterized in that the injection point of the
hot-runner injection is formed as a smooth-surfaced mark.
23. Method according to claim 19 or in particular according
thereto, characterized in that the moulding altogether consists of
the elastomer material.
24. Method according to one or more of the preceding claims or in
particular according thereto, characterized in that the hot-run
injection point is produced such that it goes over into the
surrounding moulding wall without any offset outwards.
25. Method according to one or more of the preceding claims or in
particular according thereto, characterized in that the injection
point is produced with an offset outwards with respect to the
surrounding moulding wall.
26. Method for producing a stopper (1) for pharmaceutical bottles
(3), such as for example infusion bottles, in the plastics
injection-moulding process, with a stopper top (13) and a stopper
collar (14), characterized in that a thermoplastic elastomer
material with a 30% or more admixed mineral filler content is used
and in that a central hot-runner injection (A) is performed in the
region of the stopper top (13) of the stopper (1) of a
predominantly thick-walled form.
27. Method according to claim 26 or in particular according
thereto, characterized in that the stopper collar (14) is formed
with a greater wall thickness (z) than the stopper top (13) in its
central region.
28. Method according to either of claims 26 and 27 or in particular
according thereto, characterized in that the stopper top (13) is
formed with a central region of lesser wall thickness (x) and an
edge region (15) of greater wall thickness (y).
29. Method for producing a protective cap (2) for medical syringes
in the plastics injection-moulding process, with a solid cap hat
(18) and a comparatively thin-walled cap neck (19), characterized
in that a thermoplastic elastomer material with a 30% or more
admixed mineral filler content is used and in that a central
hot-runner injection (A) is performed in the region of the cap hat
(18).
30. Method according to claim 29 or in particular according
thereto, characterized in that the hot-runner injection (A) is
performed centrally on the cap hat (18).
31. Method according to either of claims 29 and 30 or in particular
according thereto, characterized in that a proportion of
plasticizer is added to the thermoplastic elastomer material.
Description
[0001] The invention firstly relates to a moulding serving for a
pharmaceutical use, such as a stopper for pharmaceutical bottles, a
protective cap for medical syringes or a sealing element for a
pharmaceutical container.
[0002] The invention also relates to a method for producing such a
moulding.
[0003] Mouldings of this type often have aesthetic defects. Such
irregularities, impairing the visual appearance, may occur in the
form of frayed fibres and primarily form also in the region of the
injection point. Therefore, there has already been a change in the
way in which stoppers for instance are produced, arranging the
injection point in a concealed position, for example in the region
of a cavity within a stopper. Such an arrangement entails
difficulties, however, since the nozzle of the injection device
also requires a certain amount of space. Flow defects at sealing
locations, for example at a flange-like edge region of such a
stopper, facing the end edge of the flanges, may even cause sealing
problems.
[0004] In addition, mouldings of this type also have to meet high
technical requirements in other respects. For instance, during
piercing, if at all possible there must not be any crumbling away
of parts of the material, which could be entrained. Piercing must
also be possible without any hindrance. In the case of protective
caps, for instance, good material cohesion is also required,
important also for instance in the case of the other configurations
of the moulding.
[0005] On this basis, the invention is concerned with the object of
providing a moulding suitable for pharmaceutical uses which is as
homogeneous as possible and as free from defects as possible.
Furthermore, the invention is concerned with the object of
providing a production method suitable for this.
[0006] With regard to the moulding, the object is achieved firstly
and substantially by the respective subject matter of claims 1 and
2, it firstly being of significance, claim 1, in addition to the
features already specified, that the moulding consists, at least in
a subregion, of a thermoplastic elastomer material with a mineral
filler content of 30% or more and this subregion has a hot-runner
injection point which is formed as a smooth-surfaced mark. In
addition, claim 2, it is also of significance that, in the case of
a second part of the moulding, the latter consists of a different
plastics, for example a conventional injection-moulding plastics,
such as PP, PE or the like, which is then used to inject over the
injection point of the first subregion. In such a case, the
injection point of the subregion formed from the flexible elastomer
material in particular can then also be formed as a hot-runner
injection point, which is then, again preferably, also formed as a
smooth-surfaced mark. According to the invention, it has been
recognized that a thermoplastic elastomer material with a mineral
filler content of 30% or more is suitable for meeting the material
requirements of pharmaceutical mouldings of this type. This is so
at least when, in the case of outward exposure on the moulding, the
injection point is formed by a hot-runner injection point and a
smooth-surfaced mark is created. Disturbing streaking or instances
of material unevenness, in particular in the region of the
injection point, can no longer be found. Nevertheless, such a
moulding can be efficiently produced by customary
injection-moulding processes, but with hot-runner injection. It is
preferable in this context that the mark which is created on the
moulding by the hot-runner injection point goes over into the
moulding wall surrounding it without being offset outwards. In
particular, it is preferred for the smooth-surfaced mark to go over
into the moulding wall surrounding it in a co-planar manner.
Furthermore, however, it may also be recommendable in special cases
for the mark to be raised with respect to the moulding wall
surrounding it, that is to say it is offset outwards. This is so
for example if, as is the aim also of claim 2 explained above, the
two-component injection-moulding process is being used or the
moulding consisting of the elastomer material is part of a
multi-part article, in which the injection point is covered by a
further part or is even encapsulated therein. This is so because a
raised mark may also be recommendable for positive engagement in a
further part.
[0007] The moulding may altogether be of a multi-part form, by
being produced for instance in the multi-component
injection-moulding process, it being possible for the individual
parts to adhere to one another directly in the manner of welding,
or else to be separable or separate from one another after
completion of the injection process. In such a multi-part moulding,
such as that described further below in detail, the part consisting
of thermoplastic elastomer material is then a subregion of the
same.
[0008] Furthermore, it is also preferred for such a moulding, or
the corresponding subregion of the moulding, to be formed with
thick walls, at least in the region of the injection point. Thick
walls are understood here in particular with regard to a length of
the flow path of the injected material in relation to the wall
thickness. The length is measured from the injection point. Here,
furthermore, a mean value over the entire moulding is used as the
wall thickness. If a value of <5 is obtained, the walls are
considered to be thick in the sense of the present patent
application.
[0009] The moulding, or the corresponding subregion of the
moulding, takes the form of a homogeneous body. The specified
mixture produces an elastomeric structure with good piercing
behaviour. The requirements for after-sealing, for instance in the
case of pulled-out cannulas, are also satisfied.
[0010] The added mineral filler content acts with a flow-retarding
effect, which advantageously supports an aimed-for uniform
distribution of the plastics in the course of the injection
process. The hot-runner injection, which is preferably also
performed in a central region, or preferably also on an outer
surface, that is to say not in a cavity region of the moulding,
likewise promotes balanced distribution of the plastics in the
course of an injection-moulding operation. The predominantly
thick-walled formation of the moulding, or the corresponding
subregion of the moulding, also leads to substantially the same
situation with respect to shrinkage, although this is comparatively
very slight in the case of the specified material. The filler is
preferably a silicate. In may be, for example, magnesium silicate
(tallow). This filler has the effect of advantageous flow
retardation. Nevertheless, in absolute terms, the filling of a
corresponding mould cavity takes place very quickly. With the
customary size of stoppers concerned here, for instance, or other
articles of a comparable size, the filling time is about 0.1
second. There is moreover, with respect to the thermoplastic
elastomer material described, to which a plasticizer is possibly
added, a surprisingly low dependence of its properties on the
temperature. The filling of a cavity can be achieved to the
greatest extent independently of the filling temperature, without
the occurrence of a so-called spaghetti effect. The Shore hardness
A lies between 45 and 60, preferably at 55.
[0011] More specifically with respect to a stopper concerned here,
with regard to good penetrability with the cannula of a syringe it
is provided that the stopper top has a central region of lesser
wall thickness and an edge region of greater wall thickness,
measured in the vertical direction. In the use in question, the
edge region is enclosed by a flanged cap of a corresponding
infusion-bottle fastener. Possibly enclosed with a clamping
action.
[0012] The closure top is connected downwards in the vertical
direction with a stopper collar. This stopper collar likewise
preferably has, in any event in its initial region connected with
the stopper top, a greater wall thickness than the stopper top in
its central region. At the same time, the stopper collar is
consequently preferably connected with the region of greater wall
thicknesses of the edge region of the stopper. It is further
preferred for the hot-runner injection to be performed with regard
to the injection-runner closure with a ram-like needle head, the
planar end face of the needle head in the shut-off state of the
injection mould going over in a co-planar manner into the
surrounding nozzle wall, forming part of the wall of the moulding.
It can correspondingly also be stated that the smooth-surfaced
injection point, that is to say the injection area, goes over in a
co-planar manner into the surrounding surface of the moulding. A
smooth-surfaced mark of the ram-like needle head is obtained on the
moulding, effectively avoiding even extremely small instances of
roughness or fissuring. The moulding is produced without any
secondary finishing. The said configuration has the particular
advantage in the case of the stopper that no fractionation
particles, caused for instance by inaccuracies, can be carried away
through the cannula and get into the bottle. The fully formed
smooth surface consequently exists also and in particular with
respect to the injection point itself, approximately the size of a
pin head.
[0013] A further embodiment of such a moulding for pharmaceutical
uses is a protective cap for medical syringes. This protective cap
is fitted over the cannula of a syringe, in order to protect the
latter with regard to instances of mechanical impairment or else
soiling. In a corresponding way, such a protective cap also
consists of a thermoplastic elastomer material which has a mineral
filler content of 30% or more. In the region of a cap hat of the
protective cap there is a hot-runner injection. Here, the same
properties are achieved, in particular with regard to the exterior
of the protective cap, as already explained with respect to the
stopper. With regard to the material, the moulding formed as a
protective cap can also contain a proportion of plasticizer. Here,
too, the hot-runner injection is preferably performed centrally, in
the region of the tip of the cap hat. Consequently, the explanation
as provided before in detail with regard to the ram-like needle
head, which is preferably used on the injection-moulding machine
side, and the advantages achieved by this, also apply with respect
to the protective cap.
[0014] A further article which may be embodied by such a moulding
serving for pharmaceutical uses is a sealing element, as used in
the case of so-called "bottle-pack" bottles. In this respect,
reference is made in particular to the disclosure of German Patent
Applications 195 00 460 and 196 20 196, the contents of which are
hereby also incorporated in full, also for the purpose of including
features of these prior publication in claims of the present patent
application. Such a sealing element customarily has a peripheral
flange of a smaller wall thickness or, on the upper side and/or
underside, a peripheral groove associated with the edge and a
central region of greater wall thickness. Here, too, the injection
preferably takes place centrally in the upper outer surface.
Moreover, the geometrical features described also apply here, for
instance with regard to the thickness of the walls, and the
features regarding the purity and freedom from streaks, as already
explained before with respect to the moulding in general and the
other uses. In particular, such an article may also be produced in
the multi-component injection-moulding process, the one subregion,
for instance the subregion of rigid plastics forming the outer cap,
then forming the mould (again at least partially) for the
subsequently injected elastomer-material subregion. It is also
possible, however, to adopt the reverse procedure. In particular in
the latter case, it is possible, and may even be appropriate, to
produce the hot-runner injection point in such a way that it is
raised with respect to the surrounding moulding wall of elastomer
material, but in the end depressed with respect to the moulding
wall of a second subregion of another plastics component, in
particular a rigid plastics component.
[0015] The invention also relates to a method for producing a
moulding serving for pharmaceutical uses, such as for instance a
stopper for pharmaceutical bottles, a protective cap for medical
syringes or a sealing element for pharmaceutical containers. In
this respect, it is provided in one embodiment that a thermoplastic
elastomer material with a 30% or more admixed mineral filler
content is used as the material and that a central hot-runner
injection is performed in the region of a moulding top or a
moulding tip. In a further embodiment, it is provided that in any
event a subregion is produced from a thermoplastic elastomer
material with a mineral filler content of 30% or more and this
subregion is configured by an injection having an injection point,
which injection point is injected over by another plastics, forming
a second subregion of the moulding. Used here in particular is a
customary plastics for moulded parts, such as for instance PP, PE
etc. To be specific, as before in respect of the features
constituting the subject matter, a corresponding filler content in
per cent by weight is provided. Advantageously, a proportion of
plasticizers is also added to the thermoplastic elastomer material.
With regard to a stopper, it may be provided that the central
hot-runner injection is performed in the region of the stopper top,
formed predominantly with a thick wall. The stopper collar may also
be formed with a greater wall thickness than the stopper top in its
central region. With respect to a seal, the injection may be
performed in the upper outer surface, preferably centrally there.
It is further preferred, in respect of all the embodiments, that
the hot-runner closure can be used in the form of a ram-like needle
head, the planar end face of which in the shut-off state goes over
into the surrounding nozzle wall, forming part of the wall of the
moulding, in a co-planar manner or offset into the interior of the
moulding with respect to the said nozzle wall. This makes it
possible to achieve a smooth-surfaced injection point and for the
injection area of the injection point to go over into the
surrounding moulding wall in a co-planar manner or offset in terms
of depth.
[0016] When forming a protective cap for medical syringes in the
plastic injection-moulding process specified above, a solid cap hat
and a comparatively thin-walled cap neck is moulded. In an
advantageous way, the hot-runner injection takes place centrally on
the cap hat. Otherwise, from a production engineering viewpoint,
the same features as also already described above with respect to
the production of the stopper or the seal are preferred.
[0017] The subject matter of the invention is explained in more
detail below on the basis of two exemplary embodiments illustrated
in the drawing, in which:
[0018] FIG. 1 shows a stopper produced in the plastics
injection-moulding process in side view, representing the first
exemplary embodiment;
[0019] FIG. 2 shows the plan view of this;
[0020] FIG. 3 shows the view from below;
[0021] FIG. 4 shows a vertical section through an infusion bottle
with associated stopper, fastened by fitting on a flanged cap;
[0022] FIG. 5 shows a section through the mould cavity region of an
injection-moulding device, unfilled;
[0023] FIG. 6 shows an identical representation, but with the mould
cavity filled;
[0024] FIG. 7 shows a protective cap produced in the plastics
injection-moulding process for a syringe, in side view;
[0025] FIG. 8 shows a vertical section through the protective cap,
greatly enlarged, together embodying the second exemplary
embodiment;
[0026] FIG. 9 shows in side view a sealed container, as used as an
infusion bottle;
[0027] FIG. 10 shows a cross-section through the article according
to FIG. 9, in the region of the closure device in a first
embodiment;
[0028] FIG. 11 shows a representation according to FIG. 10 of a
second embodiment;
[0029] FIG. 12 shows an enlarged cross-sectional representation of
the injection region with a needle head offset into the interior
with respect to the surrounding moulding wall;
[0030] FIG. 13 shows a representation according to FIG. 6, but with
an injection point offset outwards with respect to the surrounding
moulding wall; and
[0031] FIG. 14 shows a representation of the article according to
FIG. 11, the injection point of the elastomer-material subregion
being raised with respect to the surrounding moulding wall and at
the same time accommodated in a further subregion of the
moulding.
[0032] The stopper 1 represented in FIG. 1 and the seals 38, 39
represented in FIGS. 10 and 11 and the protective cap 2 shown in
FIG. 7 are produced in the plastics injection-moulding process.
[0033] A thermoplastic elastomer material of rubber-like elasticity
and nevertheless adequate inherent rigidity is used.
[0034] The stopper 1 can be associated with a bottle 3, protecting
its contents. This is a bottle 3 which can be used in the
pharmaceutical sector, such as for example an infusion bottle.
[0035] The bottle 3 represented in FIG. 4 shows how the stopper 1
is disposed in relation to the neck 4 of the bottle 3 and secured
by a metallic flanged cap 5. The latter also accommodates an inner
cap 6. The flanged cap 5, to be designated in contrast as the outer
cap, is rolled on, going around a shoulder 7 of the bottle neck 4.
The flanging location has the reference numeral 8.
[0036] The bottle 3 consists of glass, for example.
[0037] The stopper 1 takes the form of a hollow stopper. The latter
fits in a sealing manner in a substantially cylindrical mouth 10 of
the neck 4. The cavity of the hollow stopper 9, opening towards the
space inside the bottle, has the reference numeral 11.
[0038] The stopper 1 takes the form of a pierceable closure. For
this purpose, the substantially centrally lying piercing region 12
of the stopper 1 is exposed. Details in this respect are provided
by the German Patent Application 100 05 833, which is not a prior
publication. The disclosure content of this patent application is
hereby incorporated in full, also for the purpose of including
features of the patent application referred to in claims of the
present patent application.
[0039] The piercing region 12 represents a stopper top 13, which
continues on the bottle side into a stopper collar 14.
[0040] FIG. 4 reveals for example that the stopper top 13 has a
central region, representing the piercing region 12, of lesser wall
thickness x and an edge region 15 of greater wall thickness y. The
ratio of X:Y is around 3:4 and in FIG. 5 more like 2:3, and is
based on a slightly smaller central accumulation of material, which
favours the piercing behaviour.
[0041] Taking into consideration the conditions in FIG. 5 for
example, it becomes clear that the stopper collar also has, at
least in its root region with respect to the stopper top 13, a
greater wall thickness z than the stopper top 13 in its central
region, that is the piercing region 12.
[0042] In spite of these partial differences in wall thicknesses,
the stopper 1 as a whole is of a predominantly thick-walled form.
This altogether sturdy moulding has a good final strength and is
also stable enough for the ejector 16 of the injection-moulding
device 17, partially represented in FIGS. 5 and 6.
[0043] The protective cap 2 represented in FIGS. 7 and 8 for
syringes in the medical sector is designed in terms of its walls
with other prime considerations taken into account. For instance,
the long, externally cylindrical body has a cap hat 18 of greater
material accumulation, which cap hat is continued in the
longitudinal direction into a thin-walled cap neck 19. The wall of
the cap neck 19, protectively surrounding the cannula, is hollowed
in a stepped manner on the inside; the corresponding cavity 20 goes
over into an extremely narrow zone 21, designed as a piercing zone
for protecting the proximal end of the needle body and keeping it
closed.
[0044] The neck end has the least wall thickness. In this region,
the moulding, kept substantially cylindrical over its
circumferential wall, has a prominent annular shoulder 22.
[0045] The injection point lies at the exposed point of the cap hat
18, that is at the tip of the cap hat. The quite thick-walled top
is rounded in a flat-convex manner.
[0046] Represented in FIG. 9 is a transfusion bottle 40, which has
an eyelet 41 on its base, for hanging the transfusion bottle 40
upside-down. The bottle head 42 then faces downwards.
[0047] The bottle body consists of plastics, for example PE, with a
penetrable wall thickness, for penetration by means of cannulas or
spikes, for example.
[0048] This closure wall of the bottle 40 itself is not represented
in detail. Fitted over the closure wall is a cap 43, as represented
in detail in different embodiments in FIGS. 10 and 11. Disposed
within the cap 43 is a moulding 44, which represents a seal. The
seal is pierceable and is located in front of the unrepresented
closure wall of the bottle 40. In the case of the exemplary
embodiment of FIG. 10, the seal 44 has a peripheral flange 45,
which rests on an associated flange 46 of the cap 43. The flange 45
has a much smaller wall thickness than a central region of the seal
44.
[0049] In the case of the exemplary embodiment of FIG. 11, the seal
44 has piercing regions 47, which are reduced in thickness.
Starting from the upper side and underside, hemispherical recesses
48 are formed lying back-to-back. In the region of their greatest
vertical extent, the recesses 48 have the effect that the thickness
of the seal 44 is reduced to approximately 1/5in comparison with
its greatest thickness.
[0050] In the case of the exemplary embodiment of FIG. 11, grooves
49 are also provided peripherally on the upper side and underside
of the seal 44, whereas the edge region 50 again has a vertical
extent such as that also of the central region of the seal 44, in
which the injection point is also preferably located on an outer
surface.
[0051] The mouldings in the form of the stopper 1, the protective
cap 2 and the seals 44 are not only each produced in the plastics
injection-moulding process, but also using the same material. A
thermoplastic elastomer material (TPE) is used. The material
contains an admixture of mineral filler. The filler content in this
respect is 30% or more. Magnesium silicate is preferably used as
the filler. The mineral filler has a certain flow-retarding
property, with the result that a flow cohesion occurs when filling
the mould cavity 23 of the injection-moulding device 17. The
special moulding features are explained with reference to FIGS. 5
and 6, primarily on the basis of a stopper as an example:
[0052] The injection point A (cf. for instance FIGS. 6 and 13) of
the hot-runner injection is denoted on the moulding (cf. for
example FIGS. 2, 4, 7, 8, 14) by 24. It may lie centrally on the
protective cap 2 and preferably lies centrally on the stopper 1, as
also in the case of the seals 44. This achieves the effect of a
uniform distribution at high flow rate. Aesthetic defects do not
occur. There are not even any visual irregularities such as colour
deviations. Furthermore, customary injection moulds can be used. In
this case, the cavity filling is largely temperature-independent.
It can between 200 and 280.degree. C., without any major
differences in quality being evident.
[0053] The central access of the injection moulding compound M (cf.
FIGS. 5, 6, represented using the example of injection of a
stopper), takes place via a nozzle 25 of an upper mould part 26.
The associated lower mould part is denoted by 27. The mould cavity
23 is proportionately distributed. At the centre of the lower mould
part 27 there is a vertically movable mould projection, represented
by the ejector 16.
[0054] The filling process is in each case valve-controlled. For
this purpose, a vertically movable needle 28 is located in the
upper mould part 26. Its needle head 29 enters the mouth of the
nozzle 25 in a closing manner (cf. FIG. 5).
[0055] The ram-like needle head 29 of the hot-runner injection A
has a planar end face 30. The end face extends in the shut-off
state of the hot-run injection A in a co-planar manner into the
nozzle wall 31, forming part of the moulding wall and surrounding
the mouth of the nozzle 25. The moulding wall may be the upper side
of the stopper top 13 of the stopper 1 or the corresponding surface
of the cap hat 18 of the protective cap 2 or of the seal 38 or 39
of FIGS. 10 and 11.
[0056] Referring to FIGS. 5 and 6, it can be gathered that a
horizontal gap exists between upper mould part 26 and lower mould
part 27, forming a first air discharge 32 when injected material,
that is the injection-moulding compound M, forces its way in. A
second air discharge 33 exists in the vertical direction, to be
precise in the form of an annular gap between the ejector 16 and a
receptacle of the lower mould part 27 shaped for the said ejector
to fit. As a result, complete filling of the mould cavity 23 is
achieved in the time provided, without markings such as flow
streaks or the like occurring on the outside of the moulding. The
material emerging under pressure from the nozzle 25 is not
separated by any blind hole in such a way that it cannot be vented.
If the flow path represented in FIG. 5 by arc lines B is taken as a
basis, an escape of air from the end zones a and b represented
would not be hindered because of the air discharges 32, 33
described. In the case of the articles according to FIGS. 7 and 10,
corresponding pockets are also not possible. There, the displaced
air escapes via the discharge corresponding to the first air
discharge 32.
[0057] In the case of the article of FIG. 11, it may again be
favourable to provide a plurality of air discharges of this type in
the mould.
[0058] With respect to the mouldings described, the list of
requirements in terms of the material also take into account that
such mouldings should be autoclave-resistant. They withstand
temperatures of 120.degree. over a relatively long period of time.
In spite of the admixture explained, the material remains
outstandingly suitable for injection moulding. The required
compromise has been found. Moreover, plasticizer is also added to
the thermoplastic elastomer material.
[0059] The needle 28 positioned centrally in the injection runner
35 is surrounded on the runner wall side by a heating element
36.
[0060] The nozzle wall 31 of the upper mould part 26 has in the
case of the stopper 1 or a seal 44 an annular groove 37. The
annular groove runs concentrically with respect to the nozzle 25,
is of a triangular cross-section and acts on the upper side of the
stopper top 13 as if it were a target ring 38 for the correct
placement of the cannula or a spike.
[0061] Because of the described planarity of the end face 30 of the
needle 28, there is a smooth detachment of the needle after
demoulding, i.e. without leaving behind a rough mark of a sandy
structure. To this extent, it is also not possible for
projecting-out particles to pass, during use, through the cannula
and enter the interior of the bottle 3. The mark represented in
FIG. 2 is on the one hand only emphasized for the purposes of the
drawing. On the other hand, such a mark can also be obtained if the
procedure corresponding to FIG. 12 is followed. Here, in the
shut-off state, the end face 30 of the needle 28 protrudes beyond
the surrounding nozzle wall. In a corresponding way, on the
moulding the injection region is formed such that it is offset into
the interior of the moulding. For example in the case of a needle
diameter of 1.5 mm, the offset into the interior may total 0.3 mm.
In this case, the needle tip may also be specifically formed such
that it is firstly cylindrical and then has a convex end face, it
being possible for the cylindrical region to be offset into the
interior of the moulding by 0.05 mm for example, and for the convex
end face region to be offset by a further 0.3 mm. Nevertheless, the
smooth detachment, even free from pulled strands, is retained.
[0062] Customary drafts on the moulding have been taken into
account.
[0063] Shown in FIG. 13 is a representation according to FIG. 6 in
which the injection point A of the moulding, here the stopper 13,
is formed such that it is offset outwards with respect to the
surrounding moulding wall. It is evident that, in the shut-off
state, the needle head 29 is withdrawn with respect to the
surrounding nozzle 25 to the extent that a cylindrical projection
of the moulding 13 is produced, remaining within the nozzle 25.
[0064] In the case of the embodiment of FIG. 14, the article
according to FIG. 11 is produced in the two-component
injection-moulding process, the injection point 24 being formed
such that it is offset outwards with respect to the surrounding
moulding wall, in a way corresponding to a mould-related design
according to FIG. 13. Following the moulding of elastomer material
formed here as a seal 44, the surrounding cap 44 has been moulded,
including a cap part formed here as projecting portion 51 and
extending over the injection point 24. The feature that, when
produced in the two-component injection-moulding process, the
injection point 24 of the subregion of the (overall) moulding,
which consists of thermoplastic elastomer material, has the further
subregion of the moulding of plastics of the second component
extending over it is also significant, irrespective of how the
injection point 24 is formed.
[0065] All disclosed features are (in themselves) pertinent to the
invention. The disclosure content of associated/attached priority
documents (copy of the prior application) is hereby fully
incorporated into the disclosure of the patent application, also
for the purpose of including features of these documents in claims
of the present patent application.
* * * * *