Note: Descriptions are shown in the official language in which they were submitted.
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The ~resent invention relates to the art of
glass containers and in particular to the glass bottle
protection. ~ven more particularly~ the present lnvention
relates to the protection of large-volume glass bottles
such as 1.5 litre bot~les for caxbonated soft drinks.
The last~mentioned high volume carbonated soft ~ ;
drink bottles have recently been brought under Canadian -
Government regulations due to the fact that some of the
bottles, when subjected to mechanlcal impact, for instance
on tipping over or dropping, broke and scattered glass
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particles over a relatively large area.
.
On the other hand, the large volume bottles of
the above type are of advantage from the standpoint of
family use, transportation, bottling costs, etc. ;~
.
Virtually all bottlers of carbonated soft drinks
would like to o~fer such bottles to the customers.
Many attempts have been made to solve~the problem.
The solution of the problem inevitably must be based on ~;
an assumption that a totally unbreakable glass b~-ttle simply
cannot be produced economically.
Thus, it has been proposed to envelop the bottles
in a net-llke structure intended to prevent the scattering
of the glass particles should an accidental breakage of
the bottle occur. Such protection is not only relatively
expensive butr even more importantly, reduces the
grip of the bot-~le during the use or handling in the
store or the like, thus increasing the danger of the
bottle being accidentally dropped on the floor.
113700~)
Another proposal suggests the use of a
rubber-like ring attached to the body of the bottle at
strategic locations to soften the impact on
tip-off of the bottle. It was established, however, that
such proposal is uneconomical particularly due to the
fact that it does not actually prevent scattering of glass
on breakage of a bottle. Moreover, it is extremely
expensive. It was established that the cost of such
protective rings would be in the range of several cents,
a cost totally unacceptable if one considers that the
handling of millions of bottles per year may be involved.
It has also been proposed to protect bottles by a plastic
coating applied either by dipping, spraying, adhesion or
the like whereby a substantial portion of the bottle would
be protected by a plastic coating. Reference may be had,
for instance, to Canadian patent 974,108 issued September 9,
1975 (Amberg et al) or to Canadian patent 1,013,283, issued
July 5, 1977 (Cavanagh et al). It is also known to provide
numerous systems for protection of the surfaces of glass
containers for abrasion protection, such as described in
U.S. patent 3,323,889 (Carl et al) and U.S. patent 3,420,693
(Scholes et al). The last-mentioned patent relates to the
application of thin layers of a metallic compound followed
by equally thin layers of a lubricating material. While
such treatments do provide some protection for abrasion
of the bottle, they are virtually ineffective when breakage
of a bottle occurs.
When considering prior art as referred to above,
it is also to be borne in mind that the treatment of the
bottle must allow repeated use of the bottles.
The return bottles must be
thoroughly cleansed and for this purpose strong cleansing
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substances are frequently used which would pose danger
even if a minute amount of same remained on ~he surface of
the bottle, for instance between a plastic coating and
the glass exterior of the bottle.
It is an object of the present invention to
provide a solution to the above problem which would be :
efective from the standpoint of pre~enting the scattering ~:
of glass over an unacceptably large area (some scattering
cannot be prevented even with bottles whose contents are
not under pressure, for instance ~etchup bottles, instant
coffee bottles or the like).
In accordance with one aspect of the present
invention, a method is provided for producing a composite
glass bottle of the type having a generally circular
cross-sectional configuration, a relatively large-diameter
body portio~ including a bottom section, a neck portion :
integral with said body portion and gradually decreasing in
diameter in a direction axially away from said bottom
section and terminating at a top opening section surrounded
by cap receiving and holding means, said method comprising
the steps of providing a plurality of bands of a thin, stretch-
able polymerlc film material possessing at least medium :
cling characteristics; the combined width of said bands
being slightly in excess of the periphery of said bottle
at said bottom section; subjecting each of said bands to a
relatively low stretching force; non-adhesively attaching
the bands to the surface of sald bottle at said bottom
section; winding each of said bands about the exterior
surface of the bottle along a generally helical locus
extending from said bottom section to a top portion adjacent
to but spaced from said cap holding means, to thus non-
adhesively secure each band to the exterior of the bottle
along said locus; the pitch P of said generally
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helical locus being determined by a relation H ~- P wherein
H is axial distance betweén said bottom section and said
top portion.
Preferably, P is smaller than H but greater ~han H2.
In accordance with another aspect of the present invention,
the method further comprises the step of applying peripherally
about the bottom section and about the top portion at least
one annular con~olute of a strip of said polymeric material
over the respective ends of said bands. It was found
that the use of five bands is preferable. The stretching
force applied to said bands is considerably less than
the maximum stretching force the partlcular material
can withstand. Preferably, the stretching force is less
than 15% of tear limit of the bands. The thickness of the
polymeric film màterial is preferably 300 - S00 microns.
The~bands and/or strips may be applied prior to or
after the bottling. In the latter embodiment, the
application may take place at a location remote from
the bottling plant, for instance shortly before their placing
onto the retailer's shelves. In a further aspec~, the invention provides
a composite glass bottle of the type having a generally
circular cross-sectional configuration, a relatively
large-diameter body portion including a bottom section, a ~ ~
neck portion integral with said body portion and gradually ;
decreasing in diameter in a directlon axially away from
said bottom section and terminating at a top opening
section surrounded by cap receiving and holding means;
and a pluraIity of bands of a thin, stretchable polymeric
film material non-adhesively secured to the exterior of the
bottle by at least medium cling characteristics of said
polymeric material, the bands slightly overlapping each other
and being each wound about the exterior of the bottle
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along a generally helical locus extending from said
bottom section to a top portion adjacent to but spaced
from said holding means, the pitch P of each said generally
helical locus being P ~- H; wherein H is axial distance
~etween said bottom section and said top portion.
As in the case of the method, it is preferred
that the value P be less than H. It is also preferred
that the bottle be provided with an annular layer of ~;
said polymeric film wound peripherally over
the said bands at said bottom section and said top
portion, respectively. As in the case of the method,
the number of the helically wound bands is preferably five.
The method will now be described with reference
to the accompanying drawing which shows, in diagrammatic
wayt the appl1cation of protect~ive coating in accordance
wlth the present inventlon. Reference numeral 10
designate~ a bottle, in this particular
case, a 1.5 litre bottle of Coke (trademark of The
Coca-Cola Company), it being understood that the invention
is also applicable to many other types of containers of -
similar nature. The bottle 10 as shown is a composite
bottle made of a glass core and having a generaIly
circular cross-sectional configuration as is well known
in the art. The bo~tle can be divided into several areas.
Thusl reference numeral 11 designates the body portion of
the bottle which includes a bottom section 12 and a
peripheral bottom rim section 3. The upper end of the
body 11 merges into an upwardly convargent neck portion 14
which gradually decreases in diameter in a direction axialIy
away from the bottom sec~ion 12 and terminates at a top
opening section 15 provided with a thread 16 which can also
be referred to in general terms as "cap receiving and
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holding means". The cap is also shown in a diagrammatic
way and referred to by reference numeral 17.
The glass bottle as described above is provided
with a coating which is composed of five bands 18, 19,
2Q, 21 and 22. Of the above bands, the drawing emphasi~es
the band 18 for the sake of clarity, while the remaining
:,
bands are shown in thinner lines. It is to be un~erstood,
however, that, in the shown embodlment, the bands 18 - 22
are all of the same type, strength, size and shape. Thus, the
band 19 i5 disposed to the right-hand side of band 18.
In the view of the figure of the present app~ication,
the band 20 is disposed on the remote side of the bottle
.
and thus appears colncident with band 18. At the left-h2nd ~
.. ... .: . . .
side of the figure, the bands 21 and 22 also appear as
a single band since the forward band 22 is disposed - ~
exactly in front of the band 21 as viewed in the fi~ure. -
It will be understood on review of the drawing that the
arrangement of the bands is identical regardless which
of the bands is being described. ;
The bands are made of a thin, stretchable plastic
material which per se is known in the art. For instance,
one kind of this material is known and sold under the
trademark STRETCH-N-SEAL (Trademark of Imperial Oil Limited).
Typically, the material is a sheet of stretchable polyvinyl
chloride having the thickness in the range of 350 - 700 microns.
It has been known to use such material, for instance, to
seal an open top home container by first stretching the
sheet,then bending the sheet over the edges of the top of -
the container whereupon the tendency of the material to
return to its original shape, combined with the high cling,
secures the sheet to the top of the container.
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~" The present invention utilizes the known features
o~ such material to prevent scattering of glass particles
of a broken bottle.
Turning now to the band 18, its lower en~ is applied
over the bottom rim section 13~ The respective band 18
is subjected,before and during the application, to a rel-
atively low stretchin~ force, preferably below 15% of the
maximum stretching force the material is capable of with-
standing. With the band stretched, the subsequent portions
of the band 18 (and of alL remaining bands) are wound about
the exterior of the bottle to secure same by the combined ~ ;~
cling and stretching force of the band along a generally ~;~
helical locus 23. The helical locus 23 of the band 18 extends
from the bottom rim section 13 to a top margin which can
also be referred to as a "top portion 24 disposed adjacent
to but spaced axially downwardly from the lowermost end of
cap holding means, i.e. the thread 16". The -top portion
24 thus presents an edge line representing the upper axial
end of the polymeric covering of the bottle~ It is shown
in the drawing that the pltch of the heli~ i3 generally
equal to the axial distance between the bottom rim section
13 and the top portion 24. ~n other words, there is a
single convolute of each of bands 18 - 22. A single convolute
is preferable both from the standpoint of the material
consumption and also from the standpoint of the strength
of the covering due to the orientation of tensional forces
caused by the pre-stretching of the bands 18 - 22.
Applied peripherally about the bottom section 12 are
two continuous convolutes 25 of a strip of the same polymeric ~ -
film which covers the respective bottom ends of the bands18 - 22. A similar arrangement of two convolutes 26 is
applied over the top ends of the strips 18 - 22.
It was found out that if the strips or bands are
pre stretched to less than about 15% of tear limit of the
bands or strips, directiona' orientation of the
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strength o~ the strlps is obtained which combines with medium-
to-high cling properties of the material to provide a good,
non-adhesive adherence of the material to the surface of the ~-
bottle.
The preferred number of bands 18 22 is five but
it will be appr~ciated that this particular feature is ;~
optional. The overlap between adjacent bands such as
band 18, 22 and 19 is minimum.
Since the bands 18 - 22 and convolutes 25 - 26 are
applied to the surface o~ the glass bottle solely by the -~
cling combined with the pre-stressing of the stretchable
material, the covering can easily be removed ~ `
prior to the washing of the bottle preceding subsequent
filling of same with the beverage. ~ ~;
It was determined that if the number of helical
convolutes (i.e. the pitch) of bands 18 - 22 is substantially
more than shownj the resistance of the bottle to breakage is
reduced.
1.5 Iitre Coke (trademark of The Coca Cola Company)
bottles filled with the carbonated beverage not only
withstand considerably more impact in drop tests and tip over
tests but, even more significant, on breakage, the scattering ~ ~-
of glass particles is within a relatively small area, most
of the particles having been confined to an area having
a diameter of approximately 1.5 meter and only exceptionally
reaching but staying within an area having two meters in
diameter.
The invention presents a simple, effective and
economic way of solving the problem referred to in the
introductory portion of the specification.
Those skilled in the art will readily appreciate
that further modifications or the preferred embodiment
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of the method and of the bottle shown in the enclosed
drawing are readily available. Thus, the thickness and
stretch properties of the polymeric film may vary. ~t was
found out, however, that the thickness of approximately 350
to 700 microns is sufficient ln most instances. The number
of helical convolutes may also vary, even though it is
believed that five bands 18 - 22 present optimum solution. ;
The use of a number of helically wound bands is advantageous
over a continuous film of the material due to the fact that
if the surface of the film is pierced or the like, the sub- ;
sequent tearing of the material (whlck in itself propagates
transversely of the respective strip) is limited to a
relatively small area, whereby the reduction in overall
strength of the covering is limi~ed to only one of the bands
18 - 22. The number of convolutes 25, 26 is also optional. ~ -
As a matter of fact, a single convolute with a slight overlap
may suffice in most applications. The purpose of the bottom
and top convolutes 25, 26 is to provide an added protection
against natural tendencies of many consumers, particularly
children, to peel off the bands of the protective cover.
It follows from the above that many modifications
may exist departing to a greater or lesser degree from the
preferred embodiment as described above, without departlng
from the scope of the present invention as set forth in the
accompanying claims.
