Note: Descriptions are shown in the official language in which they were submitted.
- -
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PROTECTING MEANS FOR VENTING SYSTEMS
Field of the invention
The present invention relates to a package or cap for said package
suitable for containing gasifying products. Said package or cap comprises a
venting means and a protecti,)g means for said venting means. Said
proleding means prevents contact of that said gasifying product, through
splashing during shipment and l~anspo, laliGn, with said venting means.
Backqround of the invention
The problem of package Jef~r")alion in response to pressure differences
existing between the inside of a closed package and the ambient pressure
is well known in the packaging industry. Such package deformation may be
non-recoverable for certain package materials, like some plastics or metals.
Thin-walled, partially flexible packages, often made of these sensitive
materials, are particularly subject to the problem.
There are a number of possi~l- factor-~ which may lead to the existence
of the pressure dirrerences between the inlerior and the exterior of the
package mentioned above. The co"tent of the package may, for example,
be chemically unstable or may be sul~ect to reaction with gases which may
exist in the head space of the package, or alle",alively, in certain specific
circumstances, may react with the package ",alerial itself. Any chemical
reactions involving the liquid contel,ls may lead to either production of
gases, and hence to over pressure in the package, or to the abso",lion of
any head space gases thereby causing under pressure in the package.
Pressure dirrere"ces between the pressure inside the container and the
ambient atmospheric pressure may also occur when the temperature during
the filling and sealing of the container is significantly dirrerenl from external
temperature during shipment, transporation and slGrage. Another possibility
of a pressure difference may be caused by a different ambient pressure at
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the filling of the container from another ambient pressure at a dirrere"t
geographical location.
- The prior art has proposed several sol ~tions using valve systems which
avoid pressure dirrere"ces between the inle~ior and the exterior of the
package. Proposed solutions also relate to various venting caps which allow
pressure generaled inside the package to be released by escape of gas.
For example FR-A-2 259 026 US4 136 796 and DE-A-2 509 258 disclQse
self-venting closures comprising a gas-permeable me"~bra"e covering an
orifice to the exterior. Said mei,lbranes are made of a material which is
impermeable to liquids but per",eable to gases. Tl,erefore packages may
co"~prise apertures to release gas to the exterior without losing their leak-
tightness. Another example is EP-A-593 840 which discloses contai"er~ for
containing liquids which ge"erate pressure said conlainer being made of a
thermoplastic material connlurisin9 a network of microchannels. This network
of microchannels is permeable to gases but not to liquids.
We found that should liquid product cûnlact these ",e"lbranes said
membranes may lose at least part of their gas-permeability. Also liquid
products which are viscous or which have some affinity for these
membranes may not drain away from said membrane back into the package.
Therefore should said me",bra"es become contacted by such products
their venting pe, rul'''ance is s~ ~hst~ntially lost for any part of said ",embrane
covered by the product which has not drained away from said me"lbral ,e. In
this manner it may happen that the package loses venting ca~.acily.
Prior to purchase by the consumer said product may splash onto said
,nel "brane as the filled package is agitated during shipment and
lra"s~.ollalion of the package. We found that the amount of splashes
normally occurring during shipment and transportation are sufficient to
completely interrupt the venting capacity of said package. We further found
that other venting systems like valves for example may also suffer with a
similar disadvantage.
It is therefore an object of the present invention to provide a package or
a cap for said package in which the contained product is impeded from
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contacting the venting system, thus prolonging the gas venting efficiency of
the package or the cap.
Summarv of the Invention
The present invention provides a package (10) for containing liquid
products or a cap (10) for said package. Said package, or said cap for said
package, comprises a venting means (20), which allows p~ss~ge of gases
between the interior and the exterior of said package when the pressure
inside said package is dirrerent from the ambient pressure. Said venting
means is permeable to gases, but impermeable to said liquid product. Said
package or cap for said package further co,nprises a protec~ing means (30)
which inhibits splashing of said product onto said venting means, and
whereby said protecting means allows the p~ssage of gases to said venting
means.
Brief desc, iPlion of the fiqures
Figure 1 a is a cross sectional view of the top portion of a package (shown
partially) or cap for a package with an e~lbG.Jin~ent of the protec~i"g means
accordi.)g to the present invention. Figure 1 b is a plan, top view of the same
package or cap.
Figure 2 illusl,ates the cross sectional view of a package (shown partially)
or cap for a package with another embodiment of the protecting means
according to the present invention.
Figure 3a shows cross sectional side view of a package (shown partially)
or cap for a package with a further embodiment of the protecti,)g means
according to the present invention. Figure 3b is detailed view of Figure 3a.
Figure 4a and 4b show cross secliol)al side views of a package (shown
partially) or cap for a package with another e~bodir~enl of the protecting
means according to the present invention.
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Figure 5a shows a cross sectional side view of a package (shown
partially) with a dosing cap with another embodiment of the protecting
means according to the present invention. Figure 5b shows a plan, top view
of the same package with a dosing cap.
Detailed desc, i,.lion of the invention
In the following, the drawings may refer to the upper pGI liol I of a package
as well as to a cap. A cap of the screw-on/in or snap-on/in type, or a flip-top,push-pull or turret cap closures may be engagement means between said
cap and said package.
In the following, Figure 1a will be des~ ibed first as a package, then as a
cap. In case Figure 1a shows a cross sectional view of a package, the
package (10) (only partially shown) comprises a hollow body (11). Said
hollow body is able to conlain any liquid products. rre~erably, said hollow
body is flexible to an extend that it may dero"" in response to pressure
differences arising between the inside of said package and the ambient
pressure. Pouches made of thin plastic material, for example, are also
enco",p~ssed by the present invention. Otherwise, suitable shapes of said
package may include essenlially cylindrical, tapered cylindrical, oval,
square, rectangular or flat-oval.
Said hollow body should be suitable for leak-tight co"lai"",ent of liquid
products. In the following, liquid products encol~pass also pastes, creams,
gels, emulsions and slurries. Said products may include, for exa, nple,
household products such as detergenls for laundry or dish wasllillg, hard-
surface and household cleaners, shampoos, bleaches, personal/beauty care
products, creams and tooll~pAsles Accordir,g to the present invention, said
hollow body is able to contain liquid products which generate pressure
inside said package. For example, these products may be liquid laundry
products co",p~ising a bleach, particularly peroxygen bleach. Preferably said
product has a viscosity of between 200 cps and 5000 cps, more preferably
of between 800 cps and 1800 cps, most peferably of between 1300 cps and
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1600 cps, where this viscosity is measured using a Brookfield viscosity
meter, spindie 3, 60 rpm at 20~C.
In case Figure 1a represents a cross sectional view of a cap, the cap (10)
con1,urises a top wall (17) and a side wall (18). Said cap can be engaged in a
leak tight manner to the pacl~age desc,ibed before. In another ~urefer,ed
embodiment of the present invention, said package or cap (10) may
comprise a spout (as de,ci~ted in Figure 7., 12 for exan,,~)le). Plererably, said
package or cap is made of plastic, metal, paper, or cG,n~:nalions of these
materials as layers, laminates or co-extr~d~tes The ",aterials may be also
recycled. P,erer,ed ",alerials for said hollow body include plastics such as
polyethylene (high or low density), polyvinyl chloride, polyester,
polyethylene terephlhalate (=PET), extrud~ PET, polypropylene,
polyc~r~o,)ale and nylon. These pl-cti~s may used individually or be
combined as co-extrudates, layers or lar"inates.
Another essential feature of said package or cap (10) cor"prises a venting
means (20). Said venting means is able to equalize the pressure inside said
package to the exler"al al",ospl)eric pressure. Conse~uently, said venting
means is able to avoid over pressure as well as under pressure inside said
package. Indeed, said venting means allows the escare of gases released
from the contained product from the inside to the outcide of said package, or
vice versa. Said venting means is localed in the upper portion of said
package above the level of said contained product, when said package is in
its upright position. Indeed, the gases causing the over pressure or under
pressure accumulate typically in the upper region of the package. Tl ,ereror~,
the passage of gases to the exte, ior or interior is facilitated.
Said venting means comprises at least an orifice. Prefera~ly, said venting
means comprises at least an orifice (21) and a membrane (22). Said
membrane increases the leak tigl ,lness of the package without s~ sl~nlially
decreasing the venting capacily of the package. Said orifice oonne~ the
interior of said package with the exterior. Specifically, said orifice (21 ) allows
the p~ss~ge of gases from the interior to the exterior of said package, or
vice versa, such that pressure inside said package is either maintained
identical to the extemal al",os~l ,eric pressure or at a pressure at least belowthe pressure at which significant bottle cleror",ation occurs. The dimension
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of said orifice should be suitable for said p~ssage of gases. rleferably said
orifice is circular and has a diameter of at least 0.5 mm preferi~bly between
1 mm to 3 mm. The number of orifices can be ~;hose" by a person skilled in
the art to allow a sufficient amount of flow of the gases.
Said me",brane (22) is loc~ted between the ccntel,t of said hollow body
(11) and said orifice (21) covering said orifice. r,efe,dbly said ",el,ll,rane is
impermeable to liquids but pel",eable to gases. There~ore said ",ei"bra"e
is able to provide a liquid imper",eable barrier while allowing gas venting.
r~eferably said me,nbrar,e is made of any material ca~,able of being formed
into a thin layer which may be used to cover said orifice (21). Said
membrane must be permeable to gas flow also in response to small
pressure differences. rrererably said melnbrane should allow gas flow with
pressure dirrere"ces as low as 100 mbar more preferably as low as 5 mbar.
The thickness of said n,e",bra"e is a matter of choice but preferably would
be in the region of 0.2 mm to 2 mm. Said melobra"e can comprise
essentially any material which may be fon"ed into thin layers such as
plastics paper or metal having micropores. P~ efel ,ad film ",dlel ials include
microporous plastic flms. The size of the micropores of said ",e",~ra,~e
should be such as to allow p~ss~ge of gases at low pressure difrere"ces
and at the same time to provide liquid i""~e""eability. rleferably, the
micropores will be in the range of 0.1 mm to 5 mm more p,eferal,ly between
0.2 mm to 1 mm.
r, efen ed mic, oporous plastic films for this application are:
- non-woven plastic films especially the non-woven spun bounded
polyethylene film material sold under the trade name TYVEK by the
- Du Pont Company of which TYVEK Style 10 which is fluorocarbon
treated to achieve high fluid impermeability;
- an acrylic copolymer cast on a non-woven support (nylon or PET)
with a fluoro-moner post-l, e~l" ,el ,t hyd~ ophobicity sold under the
trade name VERSAPOR by the Gelman Sciences Co"~pa"y 600
South Wagner Road Ann Arbor Ml 48106 US which is the most
p(efer, ed.
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The micr~.porous film material of said membrane (22) may be treated to
reduce its surface energy and therefore to improve the leak tightness of said
film material. The lowering of the surface energy of said film material is
particularly necess~y to improve leak tiylll,)ass when said package (10)
contains products comprising surfactant components. r, erarably in this
case, the specific sur~ace energy of said film material should be lower than
that of the s~" rdclant~ontaining product l:o achieve a sl ~hsl~n~ially completeimpermeability to the product co ntents.
Fluoro~, L,on treatment, which involves fixation of a fluoroc~, bon material,
on a micro scale, to the surface of the film material is a specific example of atreatment which provides such red~ ~c~rl surface energy. Indeed, the
fluorination treatment reduces the susceplibility of the microporous film
material of said ",elnbrane to wetting by the liquid product conlents.
However, when used to treat said ~,icr~.porous film n,alelial of said
me",brane according to the present invention, this fluoro~irbGn l,eal",en~
should not compromise the gas permeability of said me"lL)ra"e. For
example, a fluorocarbon ",alerial for use in the fluorocal6On treatment
according to the present invention is sold under the trade name
SCOTCHBAN, by the 3M Co,npany.
Said me",br~ne (22) may be applied and located inside said hollow body
(11) between the col)l6llt and said orifics (21) in any way maintaining its
liquid-impermeability and gas-per" ,eability accor~li"g to the present
invention. The means of application may thererore include the use of
adhesives, or the hcat-sealing of said ",emLra,le onto the area around said
orifice or the use of mechanical means such as clamping or hot-stamping, or
the insertion of said men,br~"e during molding of said package. As said
before, the application means employed should not significantly compromise
the venting ability of the breathable mei"l)ra"e. For this reason, it is
preferred that any adhesive used is also permeable to gases, or does not fill
up the pores of the membrane.
The membrane may be also fitted in a housing. Housings whose
dimensions are particularly compatible for use in a package or a cap
accorcling to the present invention are commercially available from GVS, Via
Roma 50, 40069, Zola Predosa (BO), Italy. In a highly preferred
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embodiment, the manufacture of said housing and the fitting of said
membrane (22) in said housing can be achieved by an "insert molding
operation", where:
- a sheet of me"~bra"e is fed into an apparatus; the sheet of
membrane is advantageousiy fed from a roll of me",brane material;
- in said apparatus, at least one r~elllbralle is cut from said sheet and
is placed into a mold wherein said housing will be for",ed,
- then, the housing is molded suhst~rltially around said mel"brane in
a manner which secures said me"~bra"e in said housing. As
"substantially around" it is meant herein that once completed, this
step should generate a housing with its fitted membrane, where both
surfaces of the me,nbrane are ~ccessihle to air, but said mel"brane
is tightly maintained in the housing.
Housings may also be manufactured by glueing or heat sealing said
membrane (22) onto a supporting material or by mechanically trapping said
mel"brane between two or more plastic pieces.
As another essential feature of the present invention, said package or
cap comprises a protecting means (30). Said protecti"g means protects the
venting means (20) from the splasl,i"g of col,lai"ed product onto said
venting means. As used herein splashing means a non continuous and brief
contact of a liquid 5~hst~-lce upon a surface when said liquid is agitated
within the package. The splashing of the contained liquid product occurs
mainly during shipment and transportation when the risk of agitation is
higher. We found that the orifice or the memLrane may lose its gas-
permeability when the contained iiquid product cGnlacts the orifice or the
membrane. Indeed, we found that liquid product or part of said product may
not sufficiently drain away from around said orifice or from said membrane
back into the package. In this manner, said orifice or said mel"brane may be
covered by the product, i.e. its venting performance is reduced for any part
of said ",embrane covered by the product which has not drained back.
Consequently, the venting capacity of the package is red~ ~ced or effectively
lost.
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This is particularly the case for liquid products which are viscous, or
which have some affinity for the me"lb,ane or for the l"aterial surrounding
the orifice. Examples are liquids exhibiting nori-newtonian flow behaviour or
liquids having a low surface energy (~ 30 dyne/cm2). For example, liquids
comprising su,ractanls exhibit typically a non-newtonian flow behaviour. As
used herein, a "non-newtonian" product is a product which presents a high
viscosity when the shear rate is low, vice versa its viscosity is low when the
shear rate is high. Conse~uently, a non-newtonian product exhibits poor
drain back characteristics, since said drain back is cha~cteri ed by a low
shear rate and the product accordingly has a high viscosity.
Prior to purchase by the consumer, especially during shipn,el,~ and
transportation of the package, said liquid product may splash onto said said
orifice or me,nbrane as the filled package is agitated. We found that th
amount of splashes normally occurring during shipment and t,anspo,lalion
are sufficient to completely interrupt the venting capacily of said package.
We found that other venting systems, lil<e valves for example, may also
suffer of a deteriorated venting capacily.
The draining away of the splashed product from the venting means may
be helped by a product repellant COdtin9 around the venting means. A
product repellant coating is any coating reducing the surface energy of the
material on which the product repellant coalil)g is applied upon. The product
tends to drain away from the regions of lower surface energy. Suitable
product repellant coating may be, for example, coating of teflon or silicone.
We found that a sufficient venting capacity of the package can be
maintained when the product repellant coating is ar)plierl on the venting
means cGi"prising at least an orifice without any me"ll~r~"e. Consequently,
this product repellant coating is a possible protecling means accor~Jing to
the present invention of a venting system. However, we found that the
A product repellant coating may deteriorate the venting capacity of a
membrane when the product repellant coating is applied directly on the
membrane of a venting means. Other types of ~.rotec~il,g means have to be
foreseen for these particular venting means.
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The protecling means according to the present invention should reduce or
completely impede these splashes of the contained liquid product onto said
venting means without disadvantages to the l"embra.,e when the venting
means further comprises a me",brane. Futher",ore the protecting means
according to the present invention has to satisfy certain consl~aints so that itdoes not interfere with the other functions of a package or a cap for a
package. Firstly said protecting means should not i"te, rere with the air flow
from the product through the venting system i.e. it should not itself interrupt
the venting of the package. Seco"dly said prote~ling means should not
interfere with the product drainage away from the venting system if the
liquid comes in contact with the venting system. Finally said protecting
means should not inl~,rere with the dispensing of the product from the
interior of the package or from a dosing cap for example during normal use.
Said protecting means (30) will be further illustrated by the following non-
limiting examples with the help of the Figures 1 to 5. Figure 1a illustrates thepackage (partially shown) or cap (10) with said venting means (20). Said
venting means comprises an orifice (21) and a me"lbr~"e (22). Said orifice
(21)is further shown in Figure 1b in a top view of said package or cap (10).
Said venting means may only comprise at least an orifice without the
membrane. However we found that the leak tightness of the package is
improved having a venting means further comprising a ",e,nbra"e. Said
package or cap further co,n,clises the prot6cti,)g means (30). Said prot6cti"g
means comprises a side wall (31) and a bottom wall (32) connected to said
side wall. Said side wall and/or bottom wall co,)".,ises at least a venting
aperture (33). Said venting aperture allows the p~ss~ge of gases towards
said venting means (20). rlererably said bottom wall co,n~lises at least an
aperture to allow drain back of product in case liquid product enters within
the volume (30a) of said protecting means. r,er~rably the venting aperture
(33) on the side wall (31)is located in the upper portion of said protecting
means when said package is in its upright position. As used herein upper
portion of said protecting means is the portion of the protecting means
which is located near said top wall (17) of said package or cap (10).
Preferably said apertures (33) on said bottom wall (32) are not in vertical
alignment with said venting means. This further prevents the contained
liquid from splashing onto said me"lbrane (22) or said venting means
.
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through said venting aperture of said botl:om wall of said protecting means
(30).
Said protecting means (30) may be an integral part of said package or
cap (10). Other possibilities are to have said side wall (31) as an integral
part of said package or cap, whereas said bottom wall (32) is a separale part
able to be attached to said side wall (31) to form the complete protecting
means (as shown in Figure 1a itself). Another possibility is shown in Figure
2, where said side wall (31') and bottorn wall (32') are a one piece part which
is dtlacl,ed to said package or cap. A furtl1er possibility is to have said sidewall and said bottom walls as two separale parts. In this case, said side wall
can be attached around said venting means and said bottom wall is
attachable to said side wall under said venting means. All these possibilities
mentioned before are applicable to all the examples as will be described
hereinafter, although they will not be explioitly repeated again.
Preferably, said bottom wall (32) should be located at a certain distance
from the bottom edge (Fig. 1, 23) of said venting means (20). Indeed, we
found that a certain distance has to be kept between said bottom wall and
the bottom edge (23) to allow the drainage of the liquid product from said
venting means back into the package through said aperture (33) of said
bottom wall. This di~lar,ce is dependent predG",i"a,ltly on the surface
tension and viscosily of the liquid. r~eferably, said dislance is at least 1 mm,more preferably between 2 mm and 5 mm.
Figure 2 illustrates a package or cap (10) with a spout (12) which is
located outside the volume cJerinêd by said protecting means (30). Any liquid
product flowing inside said volume defined by said p~tectir,g means is able
to drain back into said package through the venting aperture(s) (33). Figure
3a illustrates a package or cap with a spo~t (12') located within the voiume
(30a) defined by said protecting means (30). Said bottom wall (32')
comprises an oblique slit (34) defining a venting aperture (33). Said oblique
slit is for",ed by two baffles (32'a) and (32'b). Said baffles may overlap
and/or stay on parallel planes, but prefer~bly said baffles are not in parallel
planes, as shown in Figure 2. Preferably, a baffle (32'b) is longer than the
other baffle (32'a) and said longer baffle (32'b) is above the other baffle
(32'a). In this manner, said venting means (20) is better protected from the
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splashes of the contained liquid product. Preferably said spout (12') is
located s~bst~rltially in vertical alignment with the shorter baffle (32'a).
Therefore said longer baffle (32'b) protects the major part of said venting
means from contact with the conlai"ed liquid product even when said
contained liquid product has to enter the volume d~in~J by said protecting
means to reach the spout (12').
Figure 3b further illustrates the inclination between the two baffles (32'a)
and (32'b) of said bottom wall (32'). We found that the inclination angle of
the baffles a and the dislance between the free ends of the baffles D are
critical parar"eters to ensure protecLion against splashes of the contained
liquid product onto said venting means(20) as well as to allow the flow of
said contained liquid product towards said spout (12'). rlererably1 said angle
a is between 10~deg and 90~deg more preferably between 20~deg and
60~deg most prererably between 20~deg and 50~deg. On the other hand
said distance D is ~referably between 0.3 cm to 1 cm more ,urererably
between 0.5 cm to 1 cm.
It is u"de, ~lood that the prote~;~ing means desc, ibed in Figures 3a and 3b
can be easily adapted to said package or cap of Figure 1 a or Figure 2 by the
person skilled in the art. Dirrerenl shapes of said side wall (31) and/or said
bottom wall (32) can be selected to adapt said protectin~a means in a
package or cap and/or to improve the aesthetics of the package or cap. For
example said bottom wall may have a rounded shape.
Figure 4a shows another possibility of a package or cap (10) according to
the present invention. Said protecti,)g means comprises a cap (35) which is
manufactured as part of a housing (6) containing said l"e"~brane (22). Said
cap (35) is engaged within said housing over said me",brarle e.g. said cap
(35) is snapped over said me",brane. Said cap (35) comprises at least a
venting aperture (33) which allows the p~ss~ge of gases to and from said
venting means.
Figure 5a illustrates the cross sectional side view of a package (10')
comprising a container (16) and a cap (15). Said conlainer (16) comprises a
discharging opening (14). Said cap comprises said venting means (20) and
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said protecting means (30). Said cap comprises a top wall (17) and side wall
(18). Said cap may be adapted to be used as a dosing device.
Preferably the venting means (20) and the l~rotecting means (30) are part
or attached to the top wall of said cap (15). The prot~ctio" of said venting
~ means is best achieved when said ~u~tecting means is lor~d between said
disc;l ,arg;n53 opening (14) and said venting means. Preferably said
protecting means is a wall s~ stA-Itially per~J~"-licu~-~ to said top wall (17) of
said cap as shown in a uoss s~ctio"al top view of the cap with said
discharging opening in Figure 5b. More preferal)ly said wall (36) has a
shape of an arc in a plane parallel to said top wall. P~eferably the concave
part of said arc may be directed towards the discharging opening (as shown
in Figure 5b) or opposite towards the venting means.
P~ererably the height H and length L of said wall (36) are such that said
venting means is completely protected from any possible splashes coming
from said discharging opening (14). As herein used the height H is
measured from the top wall (17) of said cap to the lower edge (37) of said
wall and the length L is measured along the shape of said wall in the
direction which connects the two distal points of said wall. Preferably said
height H is at least such that said lower edge (37) of said protecti"g means
is below the upper edge of said discharging ope"ing (14) and said length L
is at least of the same dimension of said venting means. This ar,d"ye"lent
impedes any splashing of contained liquid product onto said venting means.
This p, otectiny means (30) does not need any venting and draining
aperture since said protecting does not form a closed volume around said
venting means. However the dislance between the venting means (20) and
the wall of the protec~iny means should be ",~i",i~ed to ensure that product
is not trapped between said venting means and said wall (36). Preferably
this distance should be greater than 2 mm more prererably it should be
greater than 4 mm.
Preferably, said protecting means is made of plastic metal paper or
combinations of these materials as layers laminates or co-extrudates. The
materials may be also recycled. Prererred "~aterials for said protecting
means include plastics such as polyethylene (high or low density) polyvinyl
chloride polyester polyethylene terephll ,alate (=PET) extrudable PET
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polypropylene, polycarbonate and nylon. These plastics may used
individually or be combined as co-extrudates, layers or laminates.
WHAT IS CLAIMED IS:
