GROUNDABLE, FLEXIBLE BULK MATERIAL CONTAINER

CONTENANT SOUPLE DE PRODUITS EN VRAC POUVANT ETRE MIS A LA TERRE

English Abstract

The invention relates to a groundable, flexible bulk material container comprising a container made of a flexible material, which has a dischargeable or conductive grid made of conductive threads (5), is alternatively dischargeable or conductive over the entire area, and further comprising at least one carrying loop (2) connected to the container (1) by means of a carrying seam (3), characterized in that at least one carrying loop (2) is equipped with a dischargeable or conductive material in a surface resistance range, measured according to TRBS 2153, from 0.1 to 108 Ohm, at least from the carrying seam (3) to the suspension point (4) over the entire surface.

French Abstract

L'invention concerne un contenant souple de produits en vrac pouvant être mis à la terre, comprenant un contenant composé d'un matériau souple qui présente une trame conductrice ou à capacité de décharge composée de fils conducteurs (5), ou qui est conducteur ou à capacité de décharge sur toute sa surface, et au moins une anse (2) qui est reliée au contenant (1) par une couture (3). Le contenant est caractérisé en ce qu'au moins une anse (2) est munie au moins à partir de la soudure (3) jusqu'au point d'accrochage (4) sur toute sa surface d'au moins un matériau conducteur ou à capacité de décharge dans une plage de résistance de surface de 0,1 à 108 ohms, mesurée selon la norme TRBS 2153.

Claims

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Claims:
1. Earthable flexible intermediate bulk container comprising:
- a container 1 made of a flexible material, which has a dissipative or
conductive grid of
conductive threads 5, or alternatively is dissipative or conductive over the
full surface area,
and
- at least one carrying strap 2 connected to the container 1 by means of a
carrying seam 3,
characterized in that at least one carrying strap 2 is provided over the full
surface area, at
least from the carrying seam 3 to the suspension point 4, with a dissipative
or conductive
material in a surface resistance range, measured in accordance with TRBS 2153,
of 0.1 to 10 8
ohms.
2. Earthable flexible intermediate bulk container, all of the carrying
straps being provided with
a conductive effect over the full surface area.
3. Earthable flexible intermediate bulk container, at least one carrying
strap being made into an
earthing lug in the bottom region.

Description

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- Groundable, flexible bulk material container
The application relates to an earthable flexible intermediate bulk container.
Earthable flexible intermediate bulk containers, Type C FIBCs, are generally
used for avoiding
risks of electrostatic ignition in areas where there is a potentially
explosive atmosphere or when
handling combustible dusts with a high level of ignition sensitivity.
Commercially available Type C FIBCs are sewn-together containers with a
carrying strap of a
flexible material in which the carrying strap makes it possible for the
container to be picked up
from above and transported (as shown for example in Figure 1). They are
generally made of a
polypropylene fabric that is provided with a dissipative or conductive grid of
conductive threads.
The connection of the conductive threads to another requires appropriate
sewing of the fabric, so
that the conductive threads of all the individual parts of the FIBC are in
good, adequate contact
with one another and with the earthable point, see also TRBS 2153 Annex B and
DIN IEC 61340-
04-04.
In practice, this connection is not always ensured in all places. In
particular there are often
problems in the region of the carrying straps, which nowadays are generally
made of insulating PP
fabric and are provided with 3 to 8 conductive threads arranged exclusively in
parallel, for one
reason because not all of the conductive threads are in adequate contact with
the earthable point -
for example, the threads may be destroyed by the sewing on of the carrying
straps - or - since they
only rest loosely on the PP fabric of the body of the FIBC ¨ they do not have
a proper earth contact.
For another reason because twisting of the carrying straps for example means
that adequate contact
of the threads with the picking-up equipment - for example a spider clamp -
which often serves as
an earthing point, is not always ensured.
From the aspect of avoiding risks of electrostatic ignition, earthing of Type
C FIBCs is a safety
measure that has to meet strict requirements and, as a result of manufacturing
defects or operating
errors, can lead to accidents (L. G. Britton, "Process Safety Progress", Vol.
12. No. 4. October
(1993), 240-250).
FIBCs are therefore additionally provided with one or more earthing jumpers,
the location of which
is not specific. Nevertheless, inadequately earthed conductive threads can
under some
circumstances lead to risks of electrostatic ignition. An FIBC that is not
earthed leads to strong
effectively igniting electrostatic spark discharges.

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The object was therefore to invent an earthable flexible intermediate bulk
container with
significantly simplified and improved earthing, without any isolated
conductive threads being able
to occur any longer in the carrying straps.
The object was achieved according to the invention by at least one carrying
strap 2 of the
intermediate bulk container being provided over the full surface area, at
least from the carrying
strap 3 to the suspension point 4, with a dissipative or conductive material
in a surface resistance
range, measured in accordance with TRBS 2153, of 0.1 to 108 ohms.
The subject matter of the application is therefore an earthable flexible
intermediate bulk container
comprising:
- a container 1 made of a flexible material, which has a dissipative or
conductive grid of
conductive threads 5, or alternatively is dissipative or conductive over the
full surface area,
and
- at least one carrying strap 2 connected to the container 1 by means of a
carrying seam 3,
characterized in that at least one carrying strap 2 is provided over the full
surface area, at least from
the carrying seam 3 to the suspension point 4, with a dissipative or
conductive material in a surface
resistance range, measured in accordance with TRBS 2153, of 0.1 to 108 ohms.
For the purposes of the invention, provision over the full surface area means
that the carrying strap
is continuously dissipative or conductive over its surface area instead of
being provided with
parallel conductive threads. For the purposes of the invention, therefore,
carrying straps are not
exclusively provided with conductive threads, a combination of conductive
threads and a full
surface area that is conductive being possible.
By providing at least one of the carrying straps with a conductive effect over
the full surface area in
the way according to the invention, these straps can be regarded as
intrinsically safe earthable
points, and the earthing can then be simply ensured firstly by way of the
picking-up equipment - for
example the conductive and earthed metal spider clamp or else the metal prongs
of a forklift truck
(always earthed in areas with potentially explosive atmospheres). Secondly, an
earthing clip may
also be securely attached to the carrying straps, and there are no longer
occasions when the FIBCs
are already regarded as unsuitable in the inspection of incoming goods just
because of inadequately
earthed conductive threads.
The material, usually polypropylene, that is necessary for the load-bearing
strength of the straps,
usually remains present as before. The conductive effect described can be
provided for example by
enclosing them in conductive foil or by conductive coating of the carrying
straps or the like.

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For reasons of flexibility/extensibility of the carrying straps, it is
sufficient to make 60% to 100 %
of the surface area of a carrying strap conductive, as long as the earthing
between the container and
the suspension point of the carrying strap is ensured, i.e. the provision of a
conductive effect begins
on one side of the carrying strap at the carrying seam.
Preferably, all of the carrying straps are provided with a conductive effect
over the full surface
area.
Should earthing jumpers be desired in the bottom region, an extension of at
least one carrying strap
in the bottom region can easily be made into an earthing lug. It is then
possible to dispense with the
additional sewing on of further earthable points, such as for example earthing
jumpers.
The carrying straps can then be referred to in the earthing instructions as
clearly identified
earthable points; in addition, if desired, an earthing symbol could be printed
onto the carrying
straps provided with a conductive effect.
Fig. 1: Type C FB3C according to the prior art, where:
1 ¨ container
2¨ carrying strap
3 ¨ carrying seam
4 ¨ suspension point
5 ¨ dissipative or conductive grid of conductive threads
6 ¨ earthing jumpers
7¨ earthing lead

Representative Drawing