Note: Descriptions are shown in the official language in which they were submitted.
The present inven~ion relates to a fla~tened flexible con-
tainer or intermediate bulk container made ready for being
filled with bulk material, and it comprises an outer con-
tainer of strong load-carrying material and an inner liner
of impervious sheet material, e.g. of thermoplastic or paper.
The invention also comprises a method for manufacturing such
containers and means for manufacturing the container.
For most applications of flexible containers it is necessary
that the material to be transported is protected against
being contaminated by dust, water etc., and this is usually
obtained by application of an impervious liner which ideally
shall be positioned against the outer container when it is
filled with a material which shall be transported and/or
stored. It has been found practical to place the liner in the
load-carrying container already at the production site of the
container. However, it has proved to be difficult to place
the liner in such a way that it will not be damaged or
crumpled and get a form which deviates from that of the outer
container, and thereby easily bursts when it is filled with
bulk material.
One way of making the above mentioned containers has been to
fasten the liner to the base material for the outer container
with glue or tape and thereafter finish sewing the outer con-
tainer. This is labour-consuming and requires great precision
in order to avoid damage of the liner during said sewing
operation. Further the tapes, and thereby the liner, can be
L~
incorrectly positioned such that it will be unevenly loaded
during filling and may then burst easily.
The final centration of the liner in the outer container can
take place by its inflation at the filling station, for in-
stance as described in GB Pat~nt No. 1.475.019 (corresponding
to Norwegian Patent No. 136.74~). The liner will then be
pressed against the outer container and be in close formation
with it, presupposing that the liner originally is cor~ectly
placed and fastened to the outer container. Accordingly, this
method presupposes great accuracy during placement of the
liner in the outer container~
In DE No. 2.721.771 it is described a container consisting of
an outer load-carrying container of roundwoven material and a
liner of thermoplastic sheet. According to this application
the sheet is centrally placed and possibly folded during
manufacture of the roundwoven base material for the load-
carrying container. ~utting of suitable pieces of sheet and
web, and closure of one end of the inner and outer container
must then be carried out in successive steps. By this method
the liner is folded by simple gusset and placed in the middle
of the container, which is folded by double gusset. Thereby
the folded liner will be placed between the central side fold
in the double-folded outer container such that the liner is
kept in place in the middle of the outer container during its
further manufacture. Even though this method secures center-
ing of the liner in the outer container, the method is
limited to manufacture of outer containers made from round-
woven material. Further one will in certain cases get pro-
blems by the final placement of the liner in connection with
securing close placement against the outer container, at
least that part of it which shall be filled with bulk
material.
The object of the present invention was to arrive at a
flexible container which when inflated or filled will have a
liner with the same form as the outer container and where the
liner everywhere lies closely against corresponding points of
the outer container, at least that part of the container
which shall be filled with bulk material, without using
fastening means as tape etc., and that crumpling of the
container is avoided.
A further object was to arrive at an apparatus and a rational
way for correct placement of the liner in the outer container
at the production site and thereby be able to manufacture a
product which is completed as far as possible there~
The most important problems experienced with flexible con-
tainers, proved to be caused by incorrect placement and
fastening of the liner at the production site. The inventors
therefore tried to change the method of placing the liner in
the outer container and a way of fastening the liner or keep-
ing it in place in the outer container. Obviously, it is no
help in placing the liner correctly at the beginning if it is
dis~laced before or during the filling operation. In order to
avoid penetration and fastening by securing the liner to the
outer container if it is displaced or incorrectly placed, the
container can of course be readymade before the liner is
placed in it. The problem will then be to place the liner
correctly in the outer container in a rational way and such
that it is not crumpled during filling of bulk material and
thereby can be damaged.
To start with the inventors chose to direct their effort on
placing the liner in the outer container after the latter
had been joined together. It was found that placement of the
liner could be carried out in a simple way and that it also
could be locked in a centered position in the outer container
without using glue or tape. The operation of placing and
fastening the liner would thereby be simpler than by pre-
viously used methods. In addition one obtained a product con-
sisting of a load-carrying outer container and a protecting
liner of impervious material which was simpler, faster and
more secure to fill with bulk material than previously known
containers where the liner was fastened to the outer con-
tainer by tape or the like. It was found that if the liner
was placed in an outer container and folded lengthwise with
the same type of gusset as the outer container, the liner
would be kept in place by the gusset or fold of the outer
container. Further would those points of the liner which are
opposite and against corresponding points in the outer con-
tainer when it was inflated or filled also be opposite each
other when the two containers were folded together. By this
way of manufacturing the container one obtained all the above
advantages.
Manufacture of such a product can be carried out in several
ways and will to a certain degree depend on whether the outer
container is made from flatwoven or roundwoven base material.
Primarily the liner and the outer container are folded with
gusset lengthwise in the same way such that the liner's
gusset is kept in place by the outer container's gusset when
the containers are flattened and that corresponding points
lie against each other such as stated above.
The inventors found a suitable way of obtaining the new pro-
duct by placing the liner in the finished outer container
which then was inflated. This was carried out in a special
way, i.e. by first placing the container in some folding
means in form of a tunnel or box having squarish cross-
section and then inflated. The longitudinal side walls were
divided in two and joined together by hinges or the like.
Subsequent to inflation the box was pressed together, and
during this operation the hinged side walls formed gussets in
both the liner and the outer container. The containers were
pressed together and could then be drawn out of the box, and
optionally they could be fslded crosswise of the longitudinal
direction and were then ready for transport to the filling
site for bulk material.
A flexible container according to the invention can be con-
nected to a filling apparatus and bulk material can be filled
directly into it without prior inflation. For some types of
bulk material inflation of the container at the filling site
can be practical for other reasons than adjustment of the
liner to the outer container. Containers according to the
invention can also be obtained in several other ways than the
above one, and some of these will be described in the follow-
ing text.
The invention is as defined in the following claims.
The invention will be further explained in connection with
the description of the figures and an example.
igure 1 shows a cross-section of the folding apparatus
with the container in inflated form.
igure 2 shows the folding apparatus with the inflated
container viewed from the side.
igure 3 shows a cross-section o~ the liner and outer
container partly folded together in a folding
apparatus.
igure ~ shows a cross-section of the folding apparatus
with the container completely pressed together.
In figure 1 is shown a folding apparatus (8) in form of a
squarish box or tunnel being open in both ends. The cross-
section of the apparatus (8) can of course deviate from the
squarish form. lt can for instance be rectangular or its
wall~ (7), roof (4) and bottom (5) can be slightly curved.
23
The apparatus (8) can be folded together as its side walls
consist of at least two longitudinal parts (7) which are
connected to each other and the roof (4) and the bottom (5)
by means of pliable ~oining means (6) which ~an be hinges,
flexible tapes or the like.
A product according to the invention can be made by first
placing a liner (2) in a completed outer container (1) which
can he equipped with lifting grip (3). Both the liner and the
container are then placed in the apparatus (8) and air is
blown into the liner (2) and pressing it against the outer
container (1) such that it touches the walls (7), roof (4)
and bottom (5) of the apparatus (8). In order to show that
one has two containers, the liner or inner container (2) is
shown on the ~igure at a certain distance from the outer
container (1), while in practice the two containers will
lie closely against each other when they are inflated.
In figure 2 there is a side view of the apparatus (8),
and one will notice parts of the containers outside the
apparatus (8) such that one can get hold of the lifting
grip (3).
In figure 3 the apparatus (8) is partly pressed together as
the roof (4) is pressed against the bottom (5), and the join-
ing means (6) of the side walls (7) are pressed against the
centre of the apparatus (8). During this pressing operation
both containers (1 and 2) are exposed to a certain air
pressure at the same time as air can get out corresponding to
lowering the roof (4) against the bottom (5). Hereby one ob-
tains that both containers are folded in the same way and
that the liner (2) all the time and all over is pressed
against the outer container (1).
~2~
In figure 4 the apparatus (8) is shown after having been
pressed completely together, and both containers are folded
in the same way. In order to clearly visualize how the con-
tainers are folded~ the roof (4) and the bottom (5) of the
apparatus (8) are drawn in an artificially large distance
from each other. The folds of the liner (2) lie in the cor-
responding folds of the outer container (1). As can be seen
from figures 3 and 4 the width of the gussets will be about
1/4 of the flat laid width of the container, i.e. about 1/8
of the container's circumferenceO By applying such deep
gussets one obtains both that the liner is kept securely in
place in correct position in the outer container and that
corresponding points in the two containers lie across each
other such as they shall when the containers are inflated or
filled with bulk material. The containers can now be drawn
out of the apparatus (8) in folded form by using the lifting
grip (3). The containers can then be folded together one or
several times and will then be ready for transport to the
filling site for bulk material.
The product according to the invention can also be made in
other ways than the one described aboveO The essential
feature of the manufacture is that the liner is placed in the
outer container and that the folding is carried out such that
both containers are folded in the same way such that the
liner everywhere lies against the outer container. This can
for instance be obtained by inflating the containers or
pressing them out crosswise before both containers are
folded. One can for instance first place the liner in on the
outer side of a rack or the like having the same form as the
cross-section of the apparatus (8) shown in figure 3. There-
upon the outer container can be placed over the liner and the
apparatus pressed together till one gets a folded two-gusset
flexible container. In order to use this method the con-
tainers must be open in one end. Duriny manufacture from
material for double-gusset flexible containers, one will
L~3~3
principally carry out the method in a similar way by round-
weaving the outer container around the continuous hose of the
liner and then place the two base materials in on a folding
apparatus such that the base material for the liner and the
outer container are folded len~thwise in the same way and
that the base material for the liner is kept in place as its
folds or gussets lie in the corresponding folds or gussets in
the outer container's base material. Base materials manufac-
tured in this way can then be cut up in suitable pieces and
joined together in at least one of their open ends by forming
bottom and lifting loops.
The present invention has given a product into which bulk
material can be filled without prior inflation at the filling
site and without damaging the liner. This leads then to less
rejection of containers and totally faster filling of the
containers. One also avoids that the liner forms pockets
which can not be utilized. Already from the moment the liner
and the outer container are folded and until they are filled
with bulk material they will be in such relative position
which they shall have when filled.
The inventors also arrived at a method for manufacturing the
product, an apparatus which both by itself is rational and
which in addition simplified the whole process from manufac-
ture of the flexible container till it i5 filled with bulk
material and is ready for further transport to storage or
application.
