Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to a method for
the manufacture of sealed, internally sterile
containers from plastics material and in particular -~
for bottles or flasks intended to be filled subsequen-
tly with pharmaceutical or food products.
The nature and characteristics of certain
products require that they are enclosed and preserved
in perfectly sterile containers. ~or these products,
it is therefore necessary to have an internally
sterile container and to fill, then seal this container
in a sterile manner. It is thus necessary either to
¢arry out all the operations in succession in the same
sterile enclosure, or to manufacture sealed sterile
containers, then subsequently to reintroduce them
into a sterile enclosure in order to open them, fill
them and finally to re-seal them within this same ;~ ;
enclosure~ ~his second method ha~ the great
advantage of making it possible to store containers ~ -
between the time o~ their manufacture and the time `~
when they are filled, without destroying their
internal aseptic condition. Unfortunately, in
practice, the closure of containers consisting of
plastics material is rarely sufficiently air-tight
to allow correct preservation of the internal aseptic
condition over a prolonged period of storage~
In fact, the manufactura of sterile containers
from plastics material is generally carried out by
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extrusion of a tubular blank, then blowing of this blank in a
mould with sterile air introduced through a needle passing
through the wall of the blank. The plastics material is thus
processed at temperatures which ensure its sterilisation, such
that the container obtained is automatically sterile. However,
closure of the orifice caused by the blowing needle in the wall
of the blank causes problems. Whether it is achieved by means
of two clamps which grip the walls consisting of plastics `
; material, between the container itself and the blowing orifice,
or by two jaws whlch close a connection obtained during blowing,
these members act on the plastics material which has already
been blown, which has come into contact with the mould, so that
it has alread~ undergone cooling. This plastics material
is no longer sufficiently maleable and furthermore is at a ~ `
temperature which is too low to enable it to weld together,
such that closure of the blowing orifice is not achieved
correctly.
The present invention intends to remedy this drawback
by facilitating perfect closure of the blowing orifice.
According to a first aspect of the invention there
is provided a method for the manufacture of a sealed sterile
container from plastics material, comprising placing a heat
softened tubular blank in a mould having two mould chambers
such that a first portion of said blank lies in a first said `
mould chamber and a second portion of said blank lies in a
second said mould chamber with said first portion being sealed
from said second portion except in the region of an orifice
establishing communication between said first and second portions,
extending a ho]low needle -through said second portion and
said orifice into said first portion, blowing sterile air through
said hollow needle to blow said first portion ïnto contact with
the walls of the first mould chamber while leaving the ~
portion unblown, withdraw;.ng said needle, and deforming the
second portion to close sald orifice and seal said first '`~
:- portion.
The second part of the blank is still maleable aEter
blowing of the first part, since. it has not come into contact
: with the cold walls of the mould. It is thus easy to weld this
plastics material which is still soft, in order to close the
blowing orifice and to obtaïn a perfect closure of the container
constituted by the first part of the blank.
According to another feature of the invention,the
second part of the blank is deformed by crushing its two opposed
walls one a~ainst the other. ~ :
~ ccording to à second aspect of the invention there
is provided a mould for the manufacture of sterile containers
comprising two mould halves defining therebetween a first
chamber inthe shape of the container to be obtained and a second
: chamber communicating with the first chamber through a conduit
such that when a tubular blank is placed in said mould and . .
said mould halves are closed said blank is divided into a f irst .
~2Q portion in said firs-t chamber and a second portion in said
second chamber, said first and second portions being sealed -~ .
from each other except in the. region of said conduit, and means
for deforming the second portion in the second chamber to close
; the second portion and therèby seal the first portion after
; sterile air has been blown into the first portion by means of
a hollow needle extending ï.nto said scond portion through
~on J
said-firs~ portion
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~ccording to a pre~erred embodiment, crushing of the
walls of the blank is obtained by the pressure exerted by means
of a piston moving in the second chamber.
According to one variat;on, the walls of the blank
are compressed by the action of fluid jets.
However, the mould remains simple to produce and is
` easy and quick to use.
The ensuing description of several embodiments given
as non-limiting examples and illustrated in the accompanying
drawings will make it easier to reveal the advantages and
features of the invention. ;~
In these drawings:
Figure 1 is à partial diagrammatic view, in section
along the interface of a mould according to the invention;
Figure 2 is a diagrammatic sectional view on line 2-2
oE figure l;
Figure 3 is a diagrammatic view of a tubular blank,
such as it becomes after closure of the mould;
Figure 4 is a partial sectional view, similar to
2Q figure 2, of part of a mould according to a variation of the
invention.
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To produce a sterile container of plastics
material, a tubul~ blank 1 is extruded, which blank
is rendered aseptic owing to the fact that it is
heated in the extruder to a temperatur~ of the order
of 180C. ~his temperature in fact ensures complete
internal and ex-ternal asepsis Or the blank.
~ he blank 1 leaving the extruder is then
placed in a mould 2, or more exactly between two
half moulds 2a~ and 2b which, when the~ are moved
towards each other9 define a chamber 3 whose shape
corresponds to that of the container to be produced,
and a pipe 5 intended to ensure the passage of a
blowing needle 6. ~he pipe 5 passes through a second
chamber 4, which is much smaller than the first, which
; 15 divides it into two portions, a pipe 5a being connected
to the two chambers 3 and 4 and constituting the
; orifice for blowing the container and a portion 5b
for the inlet of the needle, opening into a cavit~ 8
housing this needle. The closure of the two half ~ -~
moulds 2a and 2b grips the blank over the entire
periphery of the chamber 3 and thus ensures the
; welding of the walls of this blank at the ends and ,
in the space which separates the two chambers 3 and 4,
such that the blank 1 is divided into a first blank
portion 1a located inside the chamber 3 and which is
closed and into a second blank portion 1b contained
in the second chamber 4 which is separated from the
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first blan~ portion 1a and is co~nected to the latter
solely by the pipe 5a (figure 3).
The blowing needle 6, which is mounted to slide
in the pipe 5, is hollow and is connected to a source
of sterile air which is not shown. According to a ~-
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preferred embodiment, illustrated in figures 1 and 2,
-this blowing needle 6 is integral with a piston 9
which slides in a cylinder 10 parallel to the pipe 5
and is supplied alternately with fluid at its two
ends through pipes 11 and 12, in order to move the
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needle 6 between a blowing position where it is moved
along the pipe 5 and penetrates the chamber 3 and a
withdrawn position illustrated in figures n and 2,
, where it is inoperative in the cavit~ 8. A pipe 1
extends the needle 6 and moves with the latter in the
cavity 8 by sliding on the wall 15 of the base of this
oavity. When the needle 6 is in the inoperative
position illustrated in the drawings, the pipe 14 is J
` closed by the wall 15. On the other hand, when the
needle 6 is in the active position inside the pipe 5
and chamber ~, the pipe 14 connects this needle 6 to ;-
a pipe 16 for connection to a source of sterile
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blowing air or to a deflation circuit (not shown).
In this acti~e position, the needle 6 passes
through the blank portion 1b contained in the ,r
chamber ~ and the orifice 5a and opens into the
inside of the blaQ~ portion 1a which is still at a
temperature close to the extrusion temperature. '~he
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sterile air under pressure which arrives through the
passage 16, the pipe 14 and the needle 6, inflates this
first blank portion and presses the latter against the
walls of the chamber 3 where it cools rapidly in
order to become rigid. The second blank portion 1b
is not blown, since the blowing needle 6 and pipe 5
have dimensions such that, in this pipe, the material
forming the blank ensures a seal between the two -'
blank portions 1a and 1b. ~ ;
Whe`n'the s'terile air has completed s~aping by
blowing of the container 9 a system of valves which
are n'ot 'shown 'in't'e'rrupts the supply of blowing air and
connec'ts the passage 16 to the deflation circuit for '~
the purpose of 'expelling the air under pressure
contained in'the ub~ber 1a. ~luid introduced through
the`pi'p'e'12'i~to 'the cylinder 10 thus pushes back the
piston 9'in "order'to cause the withdrawal Or the needle
6 from'the bl'ank'and thus to clear the blowin~ orific'e
5a, as well as the second blank portion 1b. A
mecha~'ical:f'orce, such as for example a lateral ~; ~
pre3'sùr'e~,-i's'~hu's e'xerted on this second blank portion ~ '
1b-, in 'order'to crush its walls one against the other.
Since'the plastics material ~orming this second blank
portion 1b has'nbt been blown and has not come into
' 25 contact'with the cold wall of the chamber 4 of the
; mould-2, i-t iS :st'll at a temperature such that it is ''
' maleable and weldable. Subsequently, the blowing
ori~ice 5a:is closed by welding the walls of the bla~c
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portion 1b. The inside of the container formed in the
chamber 3 of the mould can no longer be connected to
the outside. It thus retains the inner sterility
achieved by the actual extrusion of the material.
According to the embodiment illustrated in
figures 1 and 2, the mechanical ~orce, o~ more ,~
exactly the pressure exerted on the walls of the
blank portion 1b, is obtained by means of a closure
device comprising a piston 18 sliding in a cylinder
20 whose interior is supplied alternately with fluid
through pipes 22 and 24. The rod 21 of the piston 18
comprises a flat head 26, which closes the chamber 4
in the half mould 2b and which slides in order to
increase or reduce the volume of thi~ chamber
depending on the supply of fluid to the cylinder 20.
When the pipe 24 is supplied with fluid, the head 26
presses the two walls of the blank portio~ 1b one
against the other and against the base 27 of the
chamber 4, which welds these walls together and
2~ closes the orifice 5a in an absolutely air-tight
manner. It is thus sufficient to separate the
two half moulds 2a and 2b to obtain a container which
is sealed and internally sterile.
According to a variation illustrated diagramma-
tically in figure 4, crushing of the walls of the
blank 1b is achleYed by means of jets of compressed
air which may act solely on one of the sides of the
blank 1b, like the head 26 or, as show~ in figure 4,
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be supplied by two series of condu,its 28 and 29~ :
each provided,in one of the half moulds 2a and 2b
respectively, which act in opposed directions on
each of the side walls of the second blank portion . ~ '`
1b. - ` '
; According to another variàtion of the ` ~'
invention, the closure device is formed by the rod
of the jack normally used for ejecting the container
from the mould. This jack is thus a double-
;10 acting jack, its first movement ensuring crushing
of the material of the blank portion 1b and its
second movement ensuring the ejection of the
manufactured container from the half mould 2b,
; when'the two hal~ moulds are separated. ~ ,
,. 15 Whatever the embodiment chosen, one produces '~, :
a sealed i~ternall~ sterile container whose blowing
` ' ori~ice is closed in an absolutely air-tight and .;
perfectly reliable manner 7 since this closure
operation is achieved with material which is stlll
hot and is at a temperature close to the extrusion `~
temperature~
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