Note: Descriptions are shown in the official language in which they were submitted.
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Case V-4781/V-4866
STERILIZABLE PERFORATED
PACRAGING MATERIAL
The present invention is related to
sterilizable packaging material and packages made
therefrom. Such packages are used in containers
for sterile gauze and other types of wound dress-
ings. The present invention is more particularly
related to a material for packaging articles which
can be sterilized after packaging.
In the medical field there are numerous
applications and demands for sterile articles.
Such articles include wound dressings such as gauze,
cotton, and the like, and surgical instruments such
as needles, scalpels, clamps, and the like. When
packaging these materials, difficulties are en-
countered in maintaining the articles in a sterile
condition while placing them in a package which
will maintain the sterile condition. If an item
must be handled by a packaging machine or packaging
personnel after it is sterilized, there is the
danger that the person or machine handling the item
prior to packaging will contaminate the item.
Bven if sterilization standards are maintain-
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ed, contamination can still occur when fibers breakaway from conventional packaging material such as
coated paper and non-woven sheets made from poly-
olefin fibers. These fibers can be dangerous if
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they should enter the sterile field and become
entrapped in a wound or incision and thereby
provide a situs for infection or irritation.
It is therefore highly desira~le that a non-
fibrous material be provided for making a package
which could be used to maintain items in a sterile
condition in which the items could be sterilized
while actually inside the package.
In accordance with the present invention,
there is provided a sterilizable package and a non-
fibrous perforated packaging material which can be
utilized to make a package to hold an item which
can be sterilized while it is inside the package,
the packaging material including a first layer of
perforated thermoplastic extruded film and a second
layer of perforated thermoplastic extruded film,
the first layer being oriented relative to the
second layer so that the perforations in both of
the layers are misaligned. The package of the
invention is made by placing an item to be packaged
between two sheets of the material of the invention
and connecting the sheets at their edges.
Such a material formed of two layers will
allow gas to flow through the perforations in the
layers to permit sterilizing an article contained
in a package made of the material, and then the
package can be sealed by heating the layers to
cause the heat-sealable surfaces to fuse. Thus, an
article which is desired to be sterilized can be
placed in a package made from the material of the
present invention, sterilized inside of the package
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by flowing steam or other high temperature liquids
therethrough the perforations in the package
layers, and then the perforations can be sealed by
heating the package. Also, since the film is extru-
sion formed, it is non-fibrous in nature and thus
contamination from fibers is obviated.
In a preferred embodiment of the present
invention, the packaging material comprises a first
layer of perforated thermoplastic film having at
least one heat-sealable surface and a second layer
of perforated thermoplastic film having at least
one heat-sealable surface,the first layer being
oriented relative to he second layer so that the
perforations in both of the layers are misaligned
and at least one of the heat-sealable surfaces of
one of the layers contacts at least one of the
heat-sealable surfaces of the other layer.
FIGURE 1 is a top plan view of a segment of
of the packaging material of the
present invention with the holes
; in the bottom layer shown by
broken lines;
FIGURE 2 is a cross-sectional view of the
packaging material of the present
` invention taken along lines 2-2 of
Figure l;
FIGURE 3 is a schematic of a method of
making the film of the present
lnvention
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FIGURE 4 is a perspective view of a package
made from the material of the
present invention;
FIGURE 5 is a cross-sectional view of
another embodiment of the present
invention
FIGVRE 6 is a cross-sectional view of
another embodiment of the present
invention taken along lines 2-2
of Figure l; and
FIGURE 7 is a cross-sectional view of
another embodiment of the present
invention being heat sealed.
Refering now to the drawings, the packaging
material can be seen in the drawings to be
generally indicated by the numeral 10. The
packaging material is made from two identical
layers lla and llb of the same perforated extruded
film.
Layer lla refers to the top layer as shown
in the drawings and layer llb refers to the bottom
layer. The top layer lla has holes of perforations
12 therein in protuberances 12a and the bottom
layer llb has identical holes or perforations 12
therein. The protuberances 12a face away from each
other in Figure 2.
Layers lla and llb may be any desired
plastic material such as polyethylene, poly-
propylene, or the like.
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The two layers lla and llb are oriented so
the perforations are misaligned. To maintain the
orientation of the layers lla and llb prior to
packaging an article, any means well-known in the
art may be used such as clamping at the edges,
sealing at the edges, spot sealing various small
spots at different locations on the sheet, and the
like.
Also the method shown in Figure 3 may be
used to join the sheets. The film may be fed from
rolls 28 and 29 to heated sealing rolls 30-30 to
form sheet 10.
A package 22 can be made from the material
of the invention for holding an article 23 which is
to be sterilized. Such a package is shown in
Figure 4, although any conventional package shape
or design may be used. Two sheets of material lO
are shown enclosing the article 23 to be packaged
and the edges 24 of sheets lO being sealed by
gluing, heat sealing, or the like.
After the article is placed in the package,
steam is then injected into the package as shown in
Figure 2 by the arrows. The steam travels in the
direction of the arrows through the top holes 12
and out of the bottom holes 12 to heat and
sterilize the article contained in the package.
It is thus seen that the packaging material
of the present invention can be made to form a
package in which an item can be placed and
sterilized while actually in the package. The
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package is maintained in its sterile condition
since no bacteria or other contaminants have a
straight-line path to the interior of the package.
In Figure 5 is shown a preferred embodiment
of the invention. In this embodiment, the
protuberances 12a face each other and interlock,
whereas, in Figure 2, the protuberances 12a face
away from each other.
~ f desired, each layer lla and llb could be
a laminate having more than two laminae.
Furthermore, if desired, each layer lla and llb
could have a different manner of laminae, e.g., lla
could have two laminae and layer llb could have
three laminae, so long as the inside facing laminae
are heat-sealable materials.
As shown in Figure 6, layers lla and llb
have an inner, heat-sealable lamina 16 and an outer
lamina 18. Lamina 16 may be any desired plastic ma-
terial such as polyethylene, polypropylene, or the
like. Lamina 18 may also be any desired plastic
material which is heat-sealable such as low density
polyethylene, vinyl acetate-ethylene copolymers,
vinyl acetate-propylene copolymers, and like
conventional polymers. By heat sealable is meant a
material which will bond to itself when exposed to
a heat source.
After the article is heated and sterilized,
the entire package is placed in close proximity to
heating elements 20 shown in Figure 7. Heating
elements 20 heat the inner lamina 16 to a tempera-
ture sufficiently high ~o fuse the two layers as
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indicated in Figure 4. The package is heated
sufficiently to fuse layers lla and llb together so
that no particles, bacteria, or other contaminants
can travel into the package through orifices 12.
It is thus seen that the packaging material
of the present invention can be made to form a
package in which an item can be placed and steri-
lized while actually in the package. The package
is maintained in its sterile condition by exposure
to heating source means which seals the area around
all of the perforations in the sheets to prevent
data contained in the package from being con-
taminated by any outside source of contamination.
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