U.S. patent application number 10/436407 was filed with the patent office on 2003-10-16 for perpendicular perforation on zipper tape for air evacuation of package.
Invention is credited to Plourde, Eric P., Schneider, John H..
Application Number | 20030194158 10/436407 |
Document ID | / |
Family ID | 28792245 |
Filed Date | 2003-10-16 |
United States Patent
Application |
20030194158 |
Kind Code |
A1 |
Plourde, Eric P. ; et
al. |
October 16, 2003 |
Perpendicular perforation on zipper tape for air evacuation of
package
Abstract
The plastic bags are provided with a web tape with a row of
apertures which are cut parallel to each other, but perpendicular
to the direction of travel of the row. The apertures are not
colinear with one another. The apertures are sized to allow air to
pass therethrough but not to allow selected solids to pass
therethrough. These apertures are cut with a rotating wheel with
teeth parallel to the axis of rotation and sized to provide the
apertures of the desired size.
Inventors: |
Plourde, Eric P.; (Tinley
Park, IL) ; Schneider, John H.; (Frankfort,
IL) |
Correspondence
Address: |
Gerald Levy, Esq.
PITNEY, HARDIN, KIPP & SZUCH LLP
711 Third Avenue
New York
NY
10017-4059
US
|
Family ID: |
28792245 |
Appl. No.: |
10/436407 |
Filed: |
May 12, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10436407 |
May 12, 2003 |
|
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|
09523338 |
Mar 10, 2000 |
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Current U.S.
Class: |
383/102 |
Current CPC
Class: |
B65D 33/01 20130101 |
Class at
Publication: |
383/102 |
International
Class: |
B65D 033/01 |
Claims
What is claimed is:
1. A method for providing vent apertures to a web component of a
plastic bag, comprising the steps of: providing a cutting wheel
which rotates about an axis, a periphery of said cutting wheel
including teeth which are not perpendicular to said axis; providing
an anvil means against which said cutting wheel bears, thereby
forming a nip; and drawing the web component through said nip
formed between said cutting wheel and said anvil means thereby
forming apertures in the web component cut by said teeth.
2. The method of claim 1 wherein said teeth are parallel to said
axis.
3. The method of claim 2 wherein said teeth are sized and spaced so
as to form apertures which allow air to pass therethrough, but
which do not allow selected solids to pass therethrough.
4. The method of claim 3 wherein said anvil means is a rotating
wheel.
5. The method of claim 4 wherein said web component is a zipper
tape.
6. A plastic bag including walls and a mouth formed between said
walls, at least one of said walls including a web component with a
row of apertures which are not colinear with one another, said row
of apertures being mechanically cut through said at least one
wall.
7. The plastic bag of claim 6 wherein said apertures are parallel
to each other, but perpendicular to a direction of travel of said
row.
8. The plastic bag of claim 7 wherein said apertures are sized to
allow air to pass therethrough, but not to allow selected solids to
pass therethrough.
9. The plastic bag of claim 8 wherein said web component is a
zipper tape.
10. The plastic bag of claim 6 wherein both of said walls include
said web component with said row of said apertures.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to the use of perpendicular
perforations on a zipper tape for the evacuation of air entrapped
in a package, such as a plastic bag.
[0003] 2. Description of the Prior Art
[0004] In the prior art, it is known to provide perforations to
provide for a predetermined tear line across sheet media. In order
to increase the chances that the resulting tear remains on the tear
line, the tear line can comprise colinear line segments oriented in
the direction of the perforation. However, if the perforations are
desired for some purpose other than providing a tear line, for
example to provide for evacuation of air from within a package, the
use of a tear line comprised of colinear line segments oriented in
the direction of the perforation is disadvantageous in that this
increases the chances of tear propagation along the tear line.
[0005] Prior art slit perforating uses a round wheel with raised
teeth around its periphery to cut slits which are colinear line
segments (see FIG. 1). The teeth are pressed against a hardened
anvil roller and a web, or sheet, of material is pulled between the
perforating wheel and the anvil roller. Where the tooth comes into
contact with the anvil roll a slit (cut) is left in the web.
Between the teeth the web is left intact (tie). The lengths of
these cuts and ties along with the material being perforated
determines the tendency of the web to tear along the perforation. A
low ratio of tie area to cut area is illustrated in FIG. 1 and
results in a maximized likelihood of tearing. However, in order to
minimize the likelihood of tearing, it is necessary to have a high
ratio of tie area to cut area. In other words, in order to reduce
tear tendency with traditional slit perforating, a relatively large
tie area is needed, but this large tie area would result in a low
number of slits per lineal inch.
[0006] Air evacuation slits are typically very small, such as 0.008
inches, to keep the contents of the bag (such as flour) from being
forced out through the slits when the package is compressed to
evacuate the air. A large number of slits are required to evacuate
air through the very small slits quickly enough so that it does not
slow down the automatic packaging equipment.
[0007] Moreover, air evacuation apertures for containers made from
sheets of plastic web, such as plastic bags, are frequently formed
by lasers, which can be expensive.
[0008] Prior art references disclosing tear-open elements for
carrier stock include U.S. Pat. No. 5,115,910 entitled "Carrier
Stock With Tear-Open Band Segments" issued to Klygis et al. on May
26, 1992 and U.S. Pat. No. 5,020,661 entitled "Carrier Stock With
Tear-Open Tabs" issued to Marco et al. on Jun. 4, 1991.
OBJECTS AND SUMMARY OF THE INVENTION
[0009] It is therefore an object of this invention to provide an
apparatus and method for quickly evacuating air from a package.
[0010] It is therefore a further object of this invention to
provide an apparatus and method to provide a perforation which is
tear resistant.
[0011] It is therefore a still further object of this invention to
provide an apparatus and method to provide a perforation with a
high ratio of tie area to cut area.
[0012] It is therefore a still further object of this invention to
provide an apparatus and method which achieves the above objects at
a low price.
[0013] These and other objects are attained by providing zipper
tape with a perforation comprised of a series of tears which are
parallel line segments which are perpendicular (or at least
something other than parallel or colinear) to the direction of the
perforation. A cutting wheel is used to generate this
perforation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Further objects and advantages of the invention will become
apparent from the following description and claims, and from the
accompanying drawings, wherein:
[0015] FIG. 1 is a perspective view of a cutting wheel of the prior
art providing a perforation of the prior art.
[0016] FIG. 2 is a perspective view of the cutting wheel of the
present invention providing a perforation of the present
invention.
[0017] FIG. 3 is a plan view of a typical plastic bag incorporating
the perforation of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring now to the drawings in detail wherein like
numerals indicate like elements throughout the several views, one
sees that FIG. 2 is a perspective view of cutting wheel 100 which
rotates about axis 102. The peripheral surface 104 of cutting wheel
100 includes spaced parallel blades 106 which are parallel with
axis 102. The spacing between successive blades 106 is chosen to be
equal to the desired tie length, while the length of each blade 106
is chosen to be equal to the desired cut length.
[0019] Cutting wheel 100 bears against anvil roller 200 which
rotates about axis 202. Zipper tape 10 (or other sheet media) is
drawn through the nip formed between opposing anvil roller 200 and
rotating cutting wheel 100 thereby cutting perforations 103 in the
image of the peripheral surface 104 including spaced parallel
blades 106. Perforations 103 are parallel to each other,
perpendicular to the direction of the row of perforations, and as
stated above, have a tie distance equal to the spacing between
cutting blades 106 and a cut distance equal to the length of
cutting blades 106.
[0020] Alternatively, cutting blades can be oriented in directions
which, while not colinear with each other, are something other than
parallel, such as alternating oblique lines (e.g.,
/.backslash./.backslash./.backsl-
ash./.backslash./.backslash./.backslash./.backslash./) or even
pseudo-random orientations.
[0021] A resulting typical plastic bag 20 is shown in FIG. 3,
including mouth 22 sealed by zipper profile 24 formed on zipper
tape 10. Zipper tape 10 is secured to the walls 30 of the plastic
bag 20. Perforations 103 may be formed inwardly adjacently from
zipper profile 24 and are sized to allow air within plastic bag 20
to escape while not allowing the contents of the plastic bag 20
(such as flour) to escape through perforations 103. A typical
length of the individual perforations is 0.008 inches. The parallel
non-colinear orientation of the perforations with respect to each
other results in a configuration where a tear is unlikely to
propagate along the line of perforations 103.
[0022] Thus the several aforementioned objects and advantages are
most effectively attained. Although a single preferred embodiment
of the invention has been disclosed and described in detail herein,
it should be understood that this invention is in no sense limited
thereby and its scope is to be determined by that of the appended
claims.
* * * * *