Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention relates to inflatable package
and more particularly to a self-sealing, fluid inflatable
package for use as a hot/cold pack or for the packing of
fragile objects for shipment. The invention further relates
to a one-way multiple valve construction having self-sealing
properties.
In the food industry, keeping food fresh during
shipment often requires that it be kept on ice. Single
chamber plastic sacks, filled with water and then frozen, are
often used during shipping. These sacks are typically of a
single size and shape and thus are of limited adaptahility to
varying storage and shipping demands. Accordingly, it is
clear that an ice pack that is more readily adaptable to
differing demands would be an attractive feature for users of
these devices in keeping objects cold during shipment.
Similar considerations apply in relation to domestic users of
ice/hot packs in coolers or other temporary storage media.
Furthermore, when shipping fragile objects, keeping
the object wall cushioned i5 important to limit damage due to
impact or vibration. Currently, styrofoam "chips", injected
styrofoam mouldings, "bubble" mats, popcorn and other energy
absorptive materials are used to cushion fragile objects for
shipment. Styrofoam mouldings are limiting as such cushioning
can only be reused for objects of the exact original shape and
size. Styrofoam "chips", popcorn and other packing
particulates are messy and may settle during transportation,
thus offering no cushioning effect to the object. Popcorn may
attract insects and other vermin. Bubble mats when wrapped
around an object do not securely hold that object without the
aid of tape or some other binding. All the above-described
packaging materials are themselves voluminous to both ship and
store, and all create waste disposal problems with attendant
problems of environmental degradation. Accordingly, it is
clear that a device is needed that is self-adapting to the
size and shape of the object being packed, will not settle
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during shipment, that will by its very nature secure itself
around the object, that is itself easy to ship and store, is
readily reusable or at least easily disposable and of course
is cost competitive with existing systems.
It is an object of the present invention to obviate
and mitigate from the disadvantages associated with known ice
packs and packaqing media and provide an effective and easy
to use device. In one broad aspect, the present invention
relates to a plastic self-sealing package that can be easily
filled with either air or liquid to function as eithar a
hot/cold pack or as a packing medium. ~n another broad
aspect, the present invention relates to a one-way self-
sealing valve that operates between the package and the
exterior environment as well as between a continuous row of
interconnected chambers. In a further broad aspect, the
present invenkion relates to a process for manufacturing the
self-sealing package and the various other related embodiments
of this invention. These various forms allow for the sack to
be produced for the least possible cost per linear foot while
still maintaining adequate structural integrity to the
complete system.
According to the present invention, there is
provided an inflatable package comprising outer deformable
walls defining at least one fluid-tight chamber therebetween,
valve means disposed within said chamber, and in fluid
communication therewith, said valve means permitting the
ingress of fluid into said chamber, and preventing the egress
of said fluid therefrom, said valve means including a primary
duct and at least one flow channel intersecting said primary
duct at an angle to place said primary duct in fluid
communication with the interior of said chamber~
Preferred embodiments of the present invention will
now be described in greater detail and will be better
understood when read in conjunction with the following
drawings in which:
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Figure 1 i5 a perspective view of a multiple chamber
inflatable package in accordance with the invention;
Figure 2 is a side elevational view of a one-way
multiple valve as~embly forming part of the package of Figure
1;
Figure 3 is a perspective, partially sectional view
of the valve of Figure 2 in an internally pressurized
condition;
Figure 4 is a perspective, partially sectional view
of a modification to the valve of Figure 3; and
Figure 5 is a perspective view of a further
modification to the valve of Figure 2.
With reference to Figures 1 and 2, the present
inflatable package 1 comprises two major components, namely
a deformable enclosure defined by outer walls 10 ancl a
multiple one-way valve assembly 25 which permits the ingress
o fluid into discreet pouches or chambers formed between
walls 10 and which also acts to pre~ent the egress of that
~luid once the chambers are inflated to the degree required.
Walls 10 may consist of opposed, typically
rectangular layers of pliable plastic film 11 heat sealed or
glued at their peripheral edges 9 to form a strong fluid-tight
bond therebetween. The walls are similarly bonded together
at seams 12 to sub-divide the package into discreet flu:id-
tight chambers or pouches 13, each aligned orthogonally to the
longitudinal axis of the package. In the alternative, films
11 may be printed with release varnish in the areas
representing chambers 13 so that the films can simply be fed
between opposed heat rollers to cause the sealing together of
only the unvarnished areas of the films.
It will be appreciated that walls 10 need not
necessarily be rectangular in shape, and the chambers
themselves may assume other geometric conflgurations.
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Prior to th~ heat sealing of the walls, valve
assemhly 25 is placed between the opposed layers of film 11.
As shown in Figures 3 and 4, valve 25 consists of two opposed
strips of pliable plastic film 26 and 27 sealed together along
upper peripheral edge 28 and internally as indicated by lines
30 to define an inf.initely repeated inverted U~shaped pattern.
The seals, which are fluid-tight, define a continuous
longitudinally extending primary air duct 32 and a series of
parallel, spaced apart, transversely extending flow channels
33, each of which is in fluid communication at its upstream
end 34 with primary air duct 32 and at its downstream end 35
with the interior of a respective one of chambers 13. In one
embodiment constructed by the applicant, channels 33 intersect
duct 32 at a 90 angle
Webs 37 formed between adjacent flow channels 33 are
sealed along each of their adjoini.ng edges with flow cham~els
32 and 33~ Advantageously, the webs are also sealed along
their lower edges 39 to prevent the ingress of fluid between
strips 26 and 27 and are additionally reinforced by an "X'l
shaped sea]. 41 made therein. Sealing of the valve in the
manner described above is easily accomplished by an impulse
die which descends onto films 26 and 27 to apply enough heat
to the edges and seams in question to permanently seal the two
films together to form the pattern of ducts as described
hereinabove. In the alternative, strips 26 and 27 may be
printed with release varnish and heat rollered to form the
required end product.
Although strips 26 and 27 may comprise a single
sheet of material folded over onto itself with upper edge 28
defining the fold line, a more reliably fluid-tight seal has
been found to be formed if strips 26 or 27 are sufficiently
wide to provide an overhang 43 (Figure 4) at least at the
upper but preferably at both the upper and lower edges of the
valve. Advantageously as well, the rounding of the seams at
the intersections of ducts 32 and 33 as shown most clearly in
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Figure 4 appears to reduce material fatigue when the valve is
under pressure.
After valve 25 has been intarlayered between films
11, the heat sealing together of the outer walls 10 can take
place. A release varnish applied internally in a continuous
band 51 to strips 26 and 27 within primary air duct 32
prevents the inadvertent sealing of duct 32 at its points of
intersection 54 with seams 12. The varnish can be applied of
course only to those parts of the duct intersecting with seams
12, but this would require that the valve be properly aligned
with the seams prior to the application of heat.
In use, fluid introduced under pressure at an
upstream end 70 of primary duct 32 "inflates" the duct as the
fluid travels downstream in the direction of Arrow A towards
the next adja~ent seam 12. Although the release varnish has
prevented duct 32 from being sealed completely closed at the
intersection 54, nevertheless, it requires a pressure buildup
to "pop" the intersection and before this occurs, the fluid
will enter flow channels 33 as indicated by Arrow B, flowing
therethrough into chamber 13 as indicated by Arrow C.
The fluid will then completely fill chamber 13 until
the pressure buildup in the chamber and the pressure re~uired
to pop the seal at intersection 34 equalizes. When this
occurs, the intersection will pop and fluid will flow
downstream into the next adjacent chamber via duct 32 and
channels 33 opening thereinto. This continues until as many
chambers as are needed or required are filled. The filled
portion of the package may then be detached along perforated
lines 65 formed in seams 12 for this purpose. Alternatively,
a cut using scissors or a sharpened edge can be made along the
seam.
Intersections that "pop" under pressure may be
undesirable in the event that the pressure required to cause
the pop may exceed the burst strength of films 11 or strips
26 and 27 or the seams made therein~ Accordingly, in an
alternate embodiment, additional release varnish or other seal
preventing media is applied to the internal surfaces of duct
32 to prevent or at least minimize any closure of the duct at
intersections 54. Fluid introduced at upstream end 70 will
then travel the length of duct 32 without significant
restriction. To accomplish the filling of the chambers, the
intersection 54 immediately downstream of the last chamber to
be filled is pinched off or held closed either manually or
automatically by an apparatus (not shown) dispensing the
uninflated packaging from a roll thereof. Typically, the last
~hamber will be the first to fill with successive upstream
chambers filling in order thereafter.
Depending upon the width of chamber 13, one or more
ducts 33 may open thereinto.
When the supply of pressurized fluid is removed, the
pressure in ducts 32 and 33 drops to atmospheric. This causes
the ducts to physically collapse into a substantially flat
condition under the pressure of the fluid in chambers 13 so
that the walls of the ducts are actually compressed together
in a suffocation effect to prevent the egress of fluid from
the chambers. There will be a small amount of fluid leakage
representing the fluid in the ducts at the moment of their
collapse, but beyond this, the chambers will be sealed in a
substantially fluid-tight condition.
With reference to Figure 5, there is shown a
modification in which valve 25 is formed by sealing a single
strip of plastic film 60 directly to the inner surface of one
of films 11. In other respects, this embodiment is the same
as that described above with reference to Figures 1 to 4.
This construction not only reduces the amount of plastic f:ilm
needed to construct the valve, but results in a significant
reduction in the stress to which the valve is subj~ct when
under inflation.
In one embodiment constructed by the applicant, the
material used for valve 25 is low slip (i.e. high coefficient
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of friction~ 1.5 mil polyekhylene/EVA or EVOH film which
increases the suffocation effect for one-way fluid flow when
ducts 32 and 33 collapse under pressure of the fluid in
chambers 13. Outer skin 10 may also be a polyethylene film
or nylon poly~thylene laminated film or tri-extruded
polyethylene nylon polyethylene film or polyurethane film of
varying thicknesses depending upon anticipated loads. A tri-
extruded film of LDPE/HDPE/EVA resin may also be used in view
of this material's high tensile strength, minimal tear
propagation and reasonable cost relative to competitive
plastic film products presently on the market.
It is anticipated that the present package will be
manufactured in strips of, for example, 450 linear feet for
winding onto rolls. Chamber widths will vary from a minimum
of a fraction of an inch on up. Product height may again vary
in a wide range from a few inches to a ~ew feet or more.
Outer walls 10 may be clear or opaque and may be printable for
logos, trade-marks and the like.
Chambers 13 can be filled with air for packing or
insulating purposes. Water can be used for freezing the
package into ice packs.
Other fluids than can be used include commercially
available gels useful for either cooling or heating purposes.
As many chambers as are needed can be torn off to form a pack
as large or as small as may be required. The package can be
reused or disposed of when done with.
For packaging purposes, a strip made into a closed
loop if desired can be used ~or wrapping a television,
computer or a similarly fragile commodity and then inflated,
or inflated prior to packing. This will at once conform the
shape of the strip to the merchandise being wrapped and will
cause the package to constrictively engage the merchandise to
prevent slipping. Linear strips can be used for stuffing
between the package walls and the enclosed goods. Pouches or
pocketæ can be formed for enclosing smaller goods. The
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packing will not of cvurse settle and even if the odd chamber
is punctured, this will not result in leakage from adjoining
chambers and product integrity will be substantially
maintained.
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