Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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13/~CKGROUND Ol~ I`IITS INVI,NTION
1. Field Of This Invention
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This invention relates to a container made of plastic
which consists of an outer thick-walled jacket layer and an
inner thin-walled layer. This invention also involves a pro-
cess for the production of such a container.
2. Prior Art
- The importance of plastics in the packaging industry is
becoming ever greater, and so is the problem of eliminating
the waste plastics.
The idea of reusing synthetic wastes is not new. Thus,
: empty waste containers are collected, washed and ground, and
the plastic granulates so obtained, possibly with the addition
of new material, are used again to form new plastic containers.
such containers, which are obtained from waste plastic (regen-
erated), do not satisfy from a hygenic point of view, partic-
ularly when used in the food industry, the requirements made
on them.
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An objee~ o~ tllis invcntion is to provi~G a plastic contailler
W}liC}I uscs rc~cncrate~ (recycle~) waste pla~tic an~ which is
hy~enically excellellt in performallce. Anotll~r object is to pro-
vide a ~roc~ss for pro~ucing such plastic containers. Other ob-
jects and a(lvantagcs of tllis inve1ltion are set out herein or are
obvious herefrolll to one ordinarily skille~ in the art.
The objects an~ a~vantages of this invention are obvious to one
ordinarily skilled in the art here~roln.
The plastic containers of this invention have an outer jacket
,layer made from a regenerated plastic material(s) and an'inner
layer o~ a fresh plastic material(s) compatible with the regen-
erated material(s) of the jacket layer. Only the stated inner
and outer layers are nee~ed.
The-process of this invention for the production of the contain-
ers of this lnvention includes grin~in~ up plastic eontainers
designed for recycling, using the plastic powder (regenerate) so
obtaine~ ~or the production of the outsi~e layer and coating the
2~ inside of the jacket layer with a ne~Y (freshj plastic material-
which is compatible with the regenerated plastic material of the
jacket layer. m e new plastic material is a polymer selected
from the group consisting of poLyester, a copolymerizate of
acrylonitrile-styrene, a graft copolymerizate of acrylonitrile-
butadiene-styrene, a copolymerizate of acrylonitrile-acrylic
ester, a graft polymerizate of acrylonitrile-acrylic ester on
a copolymerizate of acrylonitrile-butadiene, and a graft
polymerizate of acrylonitrile-acrylic ester on a copolymerizate
of acrylonitrile-isoprene.
The coating of the inner layer onto the outer layer
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can be carried out simultaneously with the formation of the
outer layer during the production of the entire container or
else can be carried out prior or subsequent to the formation of
the outer layer. Preferably the coating of the inner layer is
achieved simultaneously with the formation of the outer layer
during the prcduction of the entire container. For the pre-
ferred embodiment, numerous processes are available, such as,
co-extrusion-(coating-, laminating-) thermoforming, co-ex-
trusion blowing, co-injection, co-injection blowing and com-
binations thereof. According to the preferred embodiment, bothmaterials (the regenerated (recycled) plastic and the new plastic
material) are shaped simultaneously and connected or bonded.
m e regenerated plastic material and the new plastic
material must be compatible with one another. Compatibility in
the sense of this invention, means, that the properties of the
regenerated plastic material are not significantly impaired
by the addition of the plastic material of the inner layer up
to a mixing ratio of one to one.
The thickness ratio of the surface ~outer) layer and
the inside (inner)layer may vary widely, preferably, however,
a thickness ratio of the surface (outer) layer to the inside
(inner) layer between 10 to 5 and 10 to 0.01 is selected.
All of the thermoplastics can be used for the outer
layer. The plastic material for the inner layer is selected
on the basis of compatibility with the plastic material used
for the outer layer. The same plastic materlal may be used
for both layers.
According to this invention it is possible to produce
containers havlng an inner layer which consists of a plastic
material that has barrier characteristics. Such plastic
materials are, for example, polypropylene, which serves as a
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water vapor barrier, and acrylonitrile-containing plastics,
like a graft polymerizate of acrylonitrile and methylacrylate
on a copolymerizate of acrylonitrile/butadiene, which shows
a barrier effect to CO2 and 2
Typical combinations of regenerated plastic material
layer/new plastic material layer are:
:
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,
'` , ' ,'
~ 30 ~ :
..
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polyvinyl chloride/polyvinyl chloride;
polyolefin/polypropylenc;
polyester/polyester;
copolymerizatc oE acrylonitrile-styrenc/graft copolymerizate of
acrylonitrile-butadine-styrcne;
copolymerizate of acrylonitrile-methyl acrylate/graft copolymer-
. izate of acrylonitrile-butadiene-styrene; and
copolymerizate of acrylonitrile-methylacrylate/graft polymerizate
of acrylonitrile-methyl acrylate on copolymerizate of acrylonit-
rile-butadiene.
The regenerated plastic materi~l is produced by grinding, prefer-
ably under water, of the recycled containers. The number of the
cycles is not critical, as long as the demands made of the con-
tainer are fulfilled. . :
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The containers according to this invention, for example, bottles, :
~ kettles, boxes, etc., always show as a result of their special
construction a physiologically perfect inside layer and can be
used for any packaging purposes.
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I)EI~ .SCRII'l10N ~l TIII~S JNV],NTION
In the drawing:
Figure 1 is a partially cut away side-elevational view of
the plastic container of this invention;
Figure 2 is an enlarged cross-sectional view of the wall of
the container of Figure l; and
Figure 3 is another enlarged cross-sectional view of the
wall of the container of Figure 1.
In Figure 1, plastic bottle 11, consists of an outer thick-walled
layer 13 made from regenerated plastic obtained by recycling plas-
tic material and of an inner thin-walled layer 12 made from new
plastic material.
Example 1
A thermoformed preform made from a graft polymerizate of acrylon-
itrile with the trademark designation BAREX 210 was fed to the
core of an injection-blow molding machine. A copolymerizate con-
sisting of about 75 percent by weight of acrylonitrile and about
25 percent by weight of methylacrylate was injected thereon and
was blown to a container at a temperature between 140 and 170C
2~ whereby a biaxial orientation developed. The weight ratio be- ;
tween the inner BAREX 210 layer and the outer acrylonitrile-meth-
ylacrylate copolymerizate layer was 1 to 20. The container was
transparent, hard and impact resistant. The container was ground
into a granulate after using and recycling. The regenerate so
obtained was used again as a molding material for the outside
surface (jacket), as described above. The thermoformed perform
consisted of fresh BAREX 210. After ten cycles, the material of
the outside layer consisted of about 64.5 percent by weight of
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acrylonitrilc-mctllylacryl~ltc col~olymcrizate and a~out 35.5 pcr-
cent by wei~ht of BARE~ 210. This mixture, vis-a-vis the origin-
al acrylonitrile-methylacrylate copolymerizate, showed an in-
crease of tensile impact strength of about 90 percent, with the
elasticity module remaining about the same.
Example 2
As in Example 1, a preform, this time from a graft polymerizate
of acrylonitrile-styrene on butadiene-acrylonitrilc, was fed to
the core of an injection-blow molding machine and the outside
layer was formed from a copolymerizate of acrylonitrile-styrene.
~ere also the container, after use and recycling, was ground and
used again for the outside surface. The inside layer was made
from fresh graft copolymerizate of acrylonitrile-styrene.
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Example 3
As in Example 1, containers were formed where both the inside
layer as well as the outside layer consisted of polyethylene
terephthalate.
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Example 4
A composite sheet, which was produced by co-extrusion, lamin-
ation or coating and which consisted of two layers of a graft
polymerizate of acrylonitrile-methacrylate on a copolymerizate
of acrylonitrile-butadiene, ha~ing the tradename BAREX 210, was
thermoformed into a container. The regenerate, obtained by
grinding of the used and recycled container, was used for the
- production of the outside layer of a new container. The inside
layer was formed from fresh BAREX 210. After about ten such
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rccyclin~ stcps, thc ch~racteristics of thc outsi~le layer of
the container were still about the same as in the original out-
side layer.
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