Note: Descriptions are shown in the official language in which they were submitted.
W091/03430 ~ 58 Pcr/sE9o/oo5~l
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A~ DqL~o~ u~ for Use in the
~anu~acture of Hollow_~lg8~ nbi~cts
The present invention relates to a method in the manu-
facture of hollow glass objects, such as glass bottles
and jars, with the aid of at least one mould arrange
ment, in which subsequent to being removed from the
mould, but prior to being placed in position for trans-
portation to a cooling chamber or the like, each abject
lo is cooled, both externally and internally, with the aid
of a fluid coolant. The invention also relates to ap-
paratus for use when carrying out the method.
The manufacture of, for instance, glass bottles is
typically effected in two stages, the neck of the
bottle being formed in the first stage and the final
bottle shape being achieved in the second stage, by .
blowing in a two-part mould. The bottle is removed from
the mould with the aid of ~n arm-carried gripping de-
vice which grips around the neck of the bottle, so that
the bottle hangs vertically from said arm.
The U.S. Patent No. 4 553 9~9, which is assigned to -
applicant in the present case, teaches a method and
apparatus in which a glass bottle is formed and then
cooled with the use of cryogen gas while the bottle
is still located in the finishing mould.
In the manufacture of glass bottles in so-called IS-
machines, the finished bottle is lifted from the mould
and suspended for some seconds above an upwardly strea-
ming air flow, so as to cool the bottle externally, and
particularly so as to stabli~e the bottom of the bottle
prior to placiny the bottle onto a conveyor belt for
transportation to a cooling chamber. The temperature of
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W091/0~30 PCT/SE90/(iOS3l
the molten glass during bottle manufacture i5 about
1100-1200C , and it is necessary to cool the formed
bottle to a temperature of about 600C before it can be
placed on the conveyor belt. If the bot~le is not cool-
ed down to this temperature, there is a risk that thebottle will be deformed, and particularly that the
lower part of the bottle will become crooked or warped
in relation to the remainder o~ the bottle. Since the
glass is thickest at the bottom of the bottle, it is
necessary to cool the bottom of the bottle very effec-
tively. This is achieved externally with the aid of the
aforesaid upwardly moving airflow. It is necessary to
adapt the production rate of the machine concerned so
that requisite cooling can be achieved prior to placing
the bottle in position for further transportation.
EP-A2-0 071 825 describes a glass bottle manufacturing
machine, in which the glass bottles are cooled inter-
nally to some extent with the aid of air or or some
other gas. According to the descriptive part of this
prior specification, air is sprayed into the bottle th-
rough a nozzle positioned above the mouth of the bott-
le. This method, however, cannot result in effective ~;~
cooling of the bottle, particularly the bottom of the
bottle, since the temperature of the air u~ed is thesame as ambient temperature and since the air is passed
freely ~hrough the same narrow opening as that through
which the return air exits. I~ should be noted that the
pressure under which the air can be sprayed into the
bottle is limited by the risk of further blowing the
bottl~ and the ri~k of deforming the readily de-for-
mable bottle.
A primary object of the present invention is to provid~
a method by means of which the interior of a bottle and
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the bottom of said bottle can be~ cooled much more
effectively than was hitherto the case, without ris~ of
deforming the bottom of the bottle. This will enable
the production rate to be increased andtor the quality
of the finished product to be improved.
Another object is to provide apparatus for use when
carrying out the method.
The present invention is based on the realization that
the interior of a bottle and the bottom thereof can be
cooled by introducing a liquefied gas into the interior
of the hollow glass object, where the liquefied gas
vapourizes while taking-up heat from the glass. The gas
used must be chosen so that the pressure within the
bottle or object will not increase to any appreciable
extent. Furthermore, the gas will preferably have a
high thermal capacity, so that a small volume af gas
will provide effective cooling of the object.
In accordance with the invention, a method in the manu-
facture of hollow glass objects, such as glass bottles
and jars, with the aid of at least one mould arrange-
ment, in which each object is cooled with the aid of a
fluid both externally and internally subsequent to
removing said object from the mould and prior to trans-
portation of said object to a cooling chamber or the
like, which fulfills the aforesaid requirements is par-
ticularly characterized by introducing into the cavity
of said object a condensed gas, such as condensed car-
bon dioxide or condensed nitrogen, and permitting said
condensed gas to vapourize while cooling internally the
glass of said object.
Preferably, the fluid coolant used is liquid carbon
dioxide, of which at least a part first converts to a
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solid state and then vapourizes, and that the carbon
dioxide is sprayed through a pro~e which is configured
with at least one fluid passageway and which is intro-
duced into the hollow of the glass object to a depth
such as to achieve internal cooli.ng of the bottom part
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WO 91/03430 PCr/SE90/00;31
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of said object. To achieve the best cooling effect, the
carbon dioxide is sprayed in mutually different direc-
tions over the bottom of the object.
The use of carbon dioxide is highly beneficial, -ince
it can be introduced, for instance, at a pressure of
about 15 bars, which signifies a temperature of about
-40 C. When the condensed carbon dioxide is sprayed into
the bottle, in which atmospheric pressure prevails, the
solid phase obtained, i.e. carbon-dioxide snow, has a lower
temperature of about -76 C, which affords an effective
cooling action, since the amount of energy required to
vapourize the carbon-dioxide snow is very high per unit
of weight.
In accordance with one preferred embodiment of the inven-
tive method, the probe is inserted into the cavity of
said object while moving the object from the mould to a
position in which external cooling of the bottom of the
object takes place, therewith to increase the production
rate.
The particular characteric features of apparatus for
use when carrying out the method axe set forth in the
following apparatus Claims.
The invention will now be described in more detail with
reference to the accompanying drawings.
Figure 1 illustrates schematically the two first stages
of a conventional bottle manufacturing process.
Figure 2 illustrates schematically the inventive ap-
paratus for cooling a bottle manufactured in accordance
with ~igure 1, with the aid of a liquid carbon dioxide
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WO()l/0~30 ~f,S~ PCr/SE~0/005~l
coolant.
Figure 3 illustrates in larger sc:ale a probe included
in the apparatus of Figure 2.
5 In Figure 1, the reference numeral 1 identifies a bot-
tle blank moulded from molten glass in~roduced into a
first mould. The bottle blank 1 is formed in an upsiae-
down position and is held firmly by its neck, even when
the mould (not shown) has been removedO The bottle
10 blank 1 is transferred to a separatable finishing mould
5, with the aid of an arm 4 pivotally mounted on a
pivot shaft 3. The bottle blank is blown to its final
bottle form in the finishing mould. The finishing mould
is then opened and the bottle is gripped around its
15 neck and transferred to a cooling chamber, where the
bottle is cooled.
In accordance with the invention, apparatus according
to Figure 2 is used for transferring the finished bot
20 tle from the mould 5 to the cooling chamber (not
shown). The illustrated apparatus comprises a box 6
which, among other things, supports gripping means 7
for coaction with a finished bottIe 8. The box 6 also
carries a probe g which can be inserted down into a ?
25 bottle gripped by the gripping means 7. ~he probe 9 is
connected to a flexible, low-temperature hose 10 so as
- to permit the requisite vertical movement of the probe.
The end of the hose 10 distal from the probe 9 is con-
nected to an insulated supply hose 11 which leads from
30 a carbon-dioxide container 12 and which is also flex-
ible so as to permit the box 6 to move.
The box 6 is carried by an arm 14 which is pivotally
mounted on a piv~t ~haft 13 and which is operative to
35 move the box 6 between a collecting positlon and a
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W O 91/03430 PC~l/S~90/00531
5~3
cooling and laying-off position.
The illustrated embodiment of apparatus for trans-
ferring and cooling a bottle ope~.ates in the following
manner. When a bottle 8 has been blown to its final
form in the finishing mould 5, the box 6 is lowered
towards the bottle, so that the gripping means 7 are
able to grip around the neck of the bottle. At the s~,;;e
time, the probe 9 is lowered comparatively deeply into
the bottle 8. A valve (not shown) is then opened, so
that liquid carbon dioxide will flow from the container
1~ into the interior of the bottle, ~hrough the probe
9, at the same time as the bottle is being transferred
by means of the arm 4 to the laying-off position shown
in full lines in Figure ~, in which position the bottle
8 hangs above a nozzle means 15 which functions to blow
cooling air onto the outer surfaces of the bottom of
the bottle. The bottle is held in this position:for
some saconds, whereafter the bottle 8 is moved, e.g.
with the aid of a pusher 16, to a conveyor belt 17
which transports the bottle ~o a cooling chamber (not
shown).
As will be seen from the enlarged view of Figure 3, the
probe 9 of the illustrated embodiment includes four
separate passageways, suita~ly in the form of separate
pipes 18 of small dimensions in order to maintain a low
outlet pressure and therewith avoid blowing the bottle
to a larger sixe and deforming the bottle. The lower
parts of the pipes 18 are bent outwards, so as to a-
chieve effective spreading of the carbon dioxide over
the bottom of the bottle.
As mentioned in the aforegoing, the use of carbon
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WO 91/03430 PCr/SE:~0/1)0~.31
- ~?~ 35~3
dioxide as a coolant is highly advantageous, since
carbon dioxide can be introduced at relatively low
temperatures at a manageable press,ure, and also since
when carbon dioxide is sprayed int,o the bottle in which
atmospheric pressure prevails, part of the carbon
dioxide will convert to carbon-diox.ide snow which has a
lower temperature than the carbon dioxide supplied.
Consequently, there is obtained in the bottle interior
a temperature which is lower than the temperature for
which the conduits and components used to supply carbon
dioxide to the bottle need to be adapted, this lower
temperature providing more effective cooling of the
bottle interior.
By way of example, it can be mentioned that liquid
carbon dioxide can be supplied at a temperature of
about -40 C and a pressure of 15 bars. Conversion of
the liquid carbon dioxide to carbon dioxide snow:, or
dry ice, inside the bottle lowers the temperature ~o
about -76C, which results in highly effective cooling
of the bottle interior. Carbon dioxide snow also has a
very high thermal capacity and it can be mentioned by
way of example that 199 kJ are consumed when fuming-off
1 kg of liquid nitrogen at atmospheric pressure, where-
as 573 kJ are consumed when fuming-off 1 kg of carbon
dioxide snow. In addition to the aforesaid technical
advantages, the use of carbon dioxide also affords
considerable advantages from a cost aspect.
When using a probe of the illustrated configuration
wi~h the outlet orifices of the probe positioned at an
appropriate distance from the bottom of the bottle, the
carbon dioxide ~now that forms within the bottle will
be vapourized and depart in vapour or gas form before
~5 it reaches the bottom oP the bottle. The increase in
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W09l/0~30 PC1/SE90tO0~3l
Z~ L ' r,3
pressure in the bottle wl.ll be extremely moderate, will
not exceed about 0.02 b: , and consequently there ls no
risk of the bottle being deformed.
In trials in which the aforedescribed method was ap-
plied, carbon dioxide was introduced into a bottle for
a period of about 4 seconds. It was found that the
temperature of the bottom of the bottle was lowered
additionally by about 30C, which was highly advan-
tageous, since hardening of the glass mass, and there-
with the stability o~ the bottle, increases rapidly
with lowered temperatures within the range of interest.
This enables the production rate and/or the bottle
quality to be further improved. A contributory factory
in this regard is that the interior of the bottle can
be cooled while moving the bottle from the finishing
mould 5 to the laying-off position, thereby affording
an additional cooling time of about 4 seconds. The fact
that internal cooling of the bo~le commences prior to
the bottle reaching the laying-off position enabl2s the
bottle to be hung above the nozzles for external cool-
ing of the bottom o~ the bottle for a shorter period
than normal.
In the aforegoing, the invention has been described
with reference to the exemplifying embodiment illus-
trated in the drawing, where carbon dioxide is used as
the cooling agent. Cooling can also be effected advan-
tageously with other cryogen gases, such as condensed
nitro~en, while obtaining several of the aforementioned
advantages. Other variations and modifications can also
be made within the scope of the following Claims. For
example, the means for gripping and moving the bottle
may have a form different to that shown, as can also
the means by which condensed gas is supplied to the
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