Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2 ~ PS/57-17925/1+2/MA 1985
CONTAINER
The present invention relates to a package of material to be
dispersed in a liquid and to the sue of such packages. In
particular, the present ivnention relates to packages for
substances e.g. concentrated forms of agrochemicals which are
to be adde~ to water to create a dilute solution or
suspension.
There is always a need to control and limit the contact of
hazardous and potentially hazardous substances with operators
and the environment. For example many pesticides are
formulated as granules or powders which are dissolved or
dispersed in water prior to use e.g. by sprayingO When
pacXed in conventional open top drums, cartons or bags there
is a ris'~ of contamination to the crop spray operator when
tipping the pesticide into the crop spray mixing tank through
an open top manhole, especially in open, often windy
conditions. Therefore, there is a need for packages which
allow their contents to be discharged into a liquid without
exposing either the enviroT~ment or an operator to the
contents.
The present invention provides a package for contents which
are to be added to a liquid medium, wherein the package
comprises a first part which is readily soluble and/or
dispersible in the liquid medi~n and a further part which is
not readily soluble or non dispersible in the liquid medium.
; The package may include the contents which will generally be
in thc ~orm of g~anules or powder. Typicall~ the package i5
a c~t~in~r ~or granules or powdqrs, havlny an operable base
which i~ clos~d and ~eal~d by a ~trip o~ water 501uble or
disperslble paper.
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'~he container may be a bag or carton Tnade o~ pap~r or
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cardboard and which may be lined with a thin plastics sheet
e.g. of polyethylene. The base may be formed by si~ply
folding over the bottom and then securing it by means of a
strip of water soluble or dispersible paper which is fixed in
place by an adhesive.
The paper is preferably such that when wetted with water and
the container is held away from any base support, the paper
is weakened sufficiently for the weight of the contents of
the container to force open the ~ase within about 10 seconds,
preferably with 7 secondsO
Thus the container may be lowered into a tank o~ water
through a manhole to wet the base for 4-5 seconds. The
container is then lifted clear of the water surface and after
e.g~ 2-3 seconds the base is forced open by the weight of the
contents which are emptied into the tank without generating
any dust.
For ease of use the top of the container is preferably heat
sealed and fitted with a handle. In order to prevent
premature wetting e.g. by exposure to rain, the container is
preferably inside a moisture resistant outer container from
which it is removed for ~se. The outer container can also be
used to hold the dripping inside container after use, ~or
disposal.
Alternatively the soluble/dispersable part of the package may
be protected by a peelable covering o~ insoluble and non-
dispersable material. In this way the covering can be peeled
o~ to expose the soluble/dispersable part just prior to use
o~ ~he packaye.
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~he w~t~r soïuble or dispcrsible paper may he composed mainl~
oi~ ~a~box~methyl cellulose or any ~ther rnaterial which
produces a paper haviny su~ficient d~y strength to hold the
bottom o~ the container closed whe~ ~ull or product, but
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whlch rapdily becomes very weeX when wetted with water.
The thickness of the water soluble or dispersible paper can
vary depending on the size o~ the container and the weIght of
product therein. The thickness may conveniently range from
30 microns to 200 microns preferably from 60 to 200 microns
for instance.
The contents of the container may comprise one or more
fertilisers and/or pesticides, such as insecticides and
~ungicides, in powder or granular form. In addition, one or
more water soluble pacXets of a different pesticide may be
included so as to give a final solution or dispersion
containing pesticides in a predetermined ratio. The package
may also be used for other substances such as dyes or
piyments.
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In a preferred type of embodiment the invention provides a
package (generally a bag or carton) having side walls and a
base formed by folded over portion~s) of one or more side
walls, which portionts~ are not adhered to each other or to
side walls but are retained so as to provide the base by a
water soluble/dispersable patch adhered to the portion(s)
and/or side walls. Thus, dissolution or dispersion of the
patch may convert the bag to a bottomless tube, out of which
the contents can drop unimpeded.
The packages may be substantially rigid or substantially
flexible or have both flexible and rigid portions. The
packages may be in the form of bags, sacks, cartons, cups,
drums, or trays. They may be lined or unlined. ~he soluble/
di~persable part o~ the packag~ may compris~ stitching used
tQ seal ~or example a ~ag or a sack, an ahesive us~d to seal
a lid to a carton cup or drum, or pap~rs or ~ilms comprising
park o~ ~h~ package ~g. a side o~ a carton, top o~ a cup,
drum or tray, ox the base o~ a hag. Suitable mat~rial for
soluble/disp~rsabl~ ~ilms include in addi.~ion ~o
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carboxymethyl cellulose, polyvinyl alcohol (PVOH) and
polyethylene oxide (PEO~. These further materials are
thermoplastic and heat sealable. It is convenient to use
cast films and/or coated papers.
The present invention also provides a method o~ adding a
substance to a liquid medium which comprises providing the
substance in a package of the above type, and immersing at
least that part of the package which is soluble and/or
dispersible, in the medium, thus dissolving or dispersing a
part of the package to release the contents therefrom.
In order that the invention may be more easily understood,
some embodiments will be described with reference to the
accompanying drawings in which:
Fig. 1 is a bottom perspective view of a package before
closure;
Fig. 2 shows the bottom of the package of Fig. 1 folded over;
Fig. 3 shows a piece of water soluble or dipsersible paper in
position; and
~ Fig. 4 shows an unopened folded bag in plan view.
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Referring to the drawings, Figs. 1-3 show a package 10 with
walls 2, 4, 6, 8 having crease marks indicated by dash-dot
lines. The ends o~ walls 2, 4 are folded along crease lines
12, 14, 16, 18, 20, 22, and then the ends of walls 6, 8 are
folded along crease lines 24, 26 to give the position shown
in Fig. 2. ~he folded ends are then held in place by fixing
a piece of water soluble or water dispersible paper 28, as
shown in Fig. 3.
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A~t~r the package ls ~illed, e.g. with hexbicide, the top is
s~aled and lt ls th~n x~ad~ ~OI use. In use the ~ottom of
the package i9 insexted into a tank of watex in which the
h~rbicide is to be dissolved or dispersed for sp.raying. The
packa~e is then raised so that the w~t base is clear ~rom the
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water. The paper rapidly loses its strength and the weight
of the contents of the package forces the bottom open and
allows the contents to fall into the water.
The bag 100 shown in Figure 4 is self-opening satchel-shaped
bag, shown folded flat. In use, it may be unfolded to form a
cuboidal bag with an open top 112. The rectangular'base 114
of the bag 100 is conventionally formed from flaps 116, 118,
120 and 122 folded as in the form of an envelope. However,
in contrast to a conventional bag, the flaps 116, 118, 120
and 122 are not sealed to each other. Instead a rectangular
piece of material 124 is laid over the flap arrangement and
sealed thereto to effect closure of the base 114 of the bag
110. The rectangular piece of material 124 is made from
either a water soluble film or a water dispersable paper.
The material 124 is applied to the base 114 of the bag 110
using a water based pasteO
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Bags such as these are filled and closed at the top according
to conventional practices. After closure the filled bags may
be placed on a tray, placed in a carton and stored and
distributed in the conventional manner.
To use the bag 100 operator (or possibly a machine) will
grasp the bag 100 near the end 112 which has been closed.
The base 114 will then be dipped into the aqueous liquid and
then withdrawn from the liquid and suspended with the hag's
base 114 a ~ew centimetres above the liquid's sur~ace. The
water soluble/water dispersable material 124 then dissolves
or disperses so that the contents o~ the bag are released
into the liguid. As the contents of the bag 110 pass through
the a5ue4us liquid thoy are dispersed, particularly i~ the
aqueous liquid is agitated ~y stixrin~ p~ddles o~ con~inuous
l~w~ The empty bag may t~en be disposed oE as appropriate.
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