U.S. patent number RE36,501 [Application Number 09/145,666] was granted by the patent office on 2000-01-18 for method for producing inflated dunnage.
Invention is credited to Gregory A. Hoover, Roger A. Hoover, David L. Rowe, E. Riley Rowe.
United States Patent |
RE36,501 |
Hoover , et al. |
January 18, 2000 |
Method for producing inflated dunnage
Abstract
A method for producing inflated dunnage on the site of use,
comprising providing, in rolled form, a plurality of preformed
plastic bags, each of the bags comprising two plastic sheets in
facing relationship and sealed along three edges with one edge
remaining open. Air is blown toward each of the open edges in
sequence, causing each bag to inflate, and the fourth edge of each
inflated bag is sealed, the bag being empty except for the air. At
least one sealed inflated bag is separated from the roll and placed
in a carton to serve as dunnage. In an alternate embodiment, the
stock material is provided in a continuous tubular form, and an air
inflation needle is used to puncture a surface of the tube for
inflation purposes.
Inventors: |
Hoover; Gregory A. (Dunedin,
FL), Hoover; Roger A. (Dunedin, FL), Rowe; E. Riley
(Hartsville, SC), Rowe; David L. (Raleigh, NC) |
Family
ID: |
23235167 |
Appl.
No.: |
09/145,666 |
Filed: |
September 2, 1998 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
317760 |
Oct 4, 1994 |
05552003 |
Sep 3, 1996 |
|
|
Current U.S.
Class: |
156/147; 156/156;
156/292; 156/308.4; 410/119; 53/472 |
Current CPC
Class: |
B29C
66/439 (20130101); B29C 66/1122 (20130101); B31D
5/0073 (20130101); B31D 5/0078 (20130101); B63B
25/24 (20130101); B65B 43/123 (20130101); B65B
55/20 (20130101); B29C 66/4312 (20130101); B29D
22/00 (20130101); B29L 2031/7138 (20130101); B31D
2205/0023 (20130101); B31D 2205/0052 (20130101); B31D
2205/0058 (20130101); B31D 2205/007 (20130101); B29C
66/8322 (20130101); B29C 65/02 (20130101) |
Current International
Class: |
B31D
5/00 (20060101); B65B 55/00 (20060101); B65B
55/20 (20060101); B65B 43/00 (20060101); B65B
43/12 (20060101); B65B 061/00 (); B63B
025/24 () |
Field of
Search: |
;156/147,156,198,292,308.4 ;53/472,474,445 ;410/119,125 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Yao; Sam Chuan
Parent Case Text
.Iadd.This application is a reissue of Ser. No. 08/317,760, filed
on Oct. 4, 1994 now U.S. Pat. No. 5,552.003. .Iaddend.
Claims
What is claimed is:
1. Method for producing dunnage, comprising the steps of:
a) coextruding two polymers of differing tack to form a plastic
sheet having opposite surfaces of differing tack;
b) sealing said plastic sheet to another said plastic sheet so as
to form a plurality of plastic bags, each of said bags comprising
said plastic sheets in facing relationship and sealed along three
edges thereof with one edge remaining open, said bags having inner
and outer surfaces with said outer surfaces having greater tack
than said inner surfaces, and said bags being releasably attached
to each other along two opposed edges;
c) rolling up said plurality of plastic bags to form a plurality of
bags in roll form;
d) providing said plurality of plastic bags in roll form at a site
where said dunnage is to be produced;
e) unrolling said plurality of bags in roll form at said site, and
blowing air towards each said open edge in sequence, causing each
said bag to inflate;
f) sealing the fourth edge of each said inflated bag, said bag
being empty except for air of inflation;
g) separating at least one said sealed bag from said plurality of
bags in roll form; and
h) placing a plurality of said separated, sealed bags in a carton
to serve as .Iadd.interlocked .Iaddend.dunnage.
2. Method according to claim 1, wherein the bags are releasably
attached by segmenting the roll of bags longitudinally at
predetermined intervals.
3. Method according to claim 2, wherein the roll of bags is
segmented both longitudinally and laterally.
4. Method according to claim 1, wherein said bags are separated in
groups of at least two bags to form dunnage units.
5. Method according to claim 1, wherein the fourth edge is sealed
with heat. .Iadd.
6. A method for producing dunnage comprising the steps of;
a) forming a multi-layered elongated web of interconnected bags
from plastic film having outer surfaces of greater tack than inner
surfaces, the layers being interconnected such that each of the bas
has a fill openings communicating with an otherwise perimetrically
closed fill space;
b) transporting the web of interconnected bags to a site where
dunnage is to be produced;
c) sequentially blowing air through the bag fill openings to fill
the communicating fill spaces;
d) sealing each filled bag to close the fill opening of each such
filled bag;
e) separating a selected number of filled bags from the web;
and,
f) placing such separated bags as dunnage in interlocking
relationships in a package being formed. .Iaddend..Iadd.7. Method
according to claim 6, wherein the bags are releasably attached by
segmenting the web of bags laterally at predetermined intervals.
.Iaddend..Iadd.8. Method according to claim 7, wherein the web of
bags is segmented both longitudinally and laterally.
.Iaddend..Iadd.9. Method according to claim 6, wherein said bags
are separated in groups of at least two bags to form dunnage units.
.Iaddend.
Description
BACKGROUND OF THE INVENTION
The invention relates to a process for producing dunnage directly
on the site of use.
Materials with low density and high volume are commonly used as
packing materials to insulate goods being shipped from shock. Among
the materials used are polystyrene "peanuts," cups and "worms,"
pellets of foam rubber foam, plastics and expanded polyurethane
foam. Air cushioning material is generally preferred over the above
types of dunnage because it is lighter in weight, can be supplied
and dispensed in a controlled manner, particularly in roll form,
and applied to the product to be shipped in sheet form. The sheet
form of material is also easier to dispose than the individual
pieces of plastic dunnage after the product is removed, and the
sheet form of material can be rewound for further use or disposed
of by deflation.
However, air cushioning material also presents a variety of
problems, as large volumes of the material must be kept on hand,
and due to the necessity of shipping this material from the
producer, shipping costs can be considerable.
In order to overcome these problems, devices have been proposed to
produce sealed air dunnage on site from plastic sheets. U.S. Pat.
Nos. 5,188,691, 5,203,761, and 4,576,669 all propose devices for
producing air filled dunnage, typically bubble wrap, from plastic
sheets on an "on demand" basis.
U.S. Pat. No. 3,575,757 discloses a process for producing dunnage
on site from plastic sheets in which opposed sheets are bonded
together in a U-shaped seal to form a pocket, the pocket is
inflated and then sealed by the formation of a subsequent U-shaped
seal.
However, the above methods of producing dunnage are somewhat
disadvantageous, as the apparatus necessary to handle two separate
sheets of plastic is somewhat complex and difficult to operate.
When used on site, it is typically operated by people whose
expertise is not in the production of dunnage and who have some
difficulty operating the equipment at peak efficiency.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to produce dunnage on
site in a simplified manner.
It is a further object of the invention to provide dunnage on site
by a method which can be operated easily by personnel without
expertise in the production of dunnage.
To achieve these and other objects, the present invention provides
a method for producing dunnage comprising the steps of providing,
in roll form, a plurality of preformed plastic bags, each of said
bags comprising two plastic sheets in facing relationship and
sealed along three edges thereof with one edge remaining open, the
bags being releasably attached in sequence along two opposed edges,
blowing air toward each said open edge causing each said bag to
inflate in sequence, sealing the fourth edge of each said inflated
bag, the bag being empty except for air during the sealing
operation, separating at least one sealed inflated bag from the
roll of bags and placing the separated sealed bag in a carton to
serve as dunnage.
Typically, a roll of bags will be provided which is segmented
longitudinally, but a roll can also be provided which is segmented
both longitudinally and laterally, to produce a roll with, for
example, four bags across or eight bags across. The bags can be
separated from the roll individually and placed in a carton, or can
be separated in groups of at least two bags, and typically more.
This is advantageous, as the dunnage which is produced can be
wrapped around an object and taped together just as bubble wrap
would be, and which is as easy to dispose of or reuse as bubble
wrap. The inflated dunnage of the invention is, however, much
easier to produce than bubble wrap.
In a particularly preferred embodiment of the invention, the
external surface of the bags can be treated to impart greater tack,
as compared with the inner surface. Increasing the tackiness of the
surface of plastic bags in order to enable them to open more easily
is known, for example, from U.S. Pat. No. 4,904,092, in which bags
are coated with an adhesive. Alternatively, a tacky outer surface
can be provided by coextruding two or more bag layers of differing
tack. Increasing the tack of this outside surface of the bags is
also desirable in that the bags will tend to interlock in use and
prevent the packaged product from moving.
Various types and thicknesses of material can be used to make the
bags of the invention. Among these materials are nylon film, high
density polyethylene and low density polyethylene. Nylon film will
keep air trapped for a long period of time, while high density
polyethylene is strong and also holds air for a long period of
time. Low density polyethylene tends to be inexpensive and will
typically be used. The thickness of the films can be adjusted to
provide extra strength or light weight, depending on which
properties are desired.
It is also possible to produce the plastic film with degradable
additives in order to aid in disposal.
Importantly, the apparatus used to inflate and seal plastic bags is
well known and easy to operate. Typically, an air filled sealed bag
will be used for packaging a small article. In this regard, U.S.
Pat. Nos. 3,254,828, 3,298,156 and 3,477,196 are cited as
representative patents showing methods and apparatus for blowing
open bags on rolls, and U.S. Pat. No. 4,103,471 is cited to show an
apparatus for packaging materials in a protective atmosphere, in
which a foodstuff is packaged in a bag under an inert atmosphere
and the bag is then sealed.
In an additional embodiment of the invention, the starting material
is not a roll of plastic bags, but rather a stock material
comprising two plastic sheets in facing relationship which are
sealed together along the longitudinal outer edges, or a single
sheet sealed into tubular form. This roll of stock material is
unrolled and a first lateral seal is placed across the material.
Unrolling is then continued, and an inflation needle punctures one
of the plastic sheets. Air is blown through the needle, causing an
inflated "pillow" to form at least between the needle and the seal.
In carrying out this process, the inflated area actually extends
back as far as the point which there is pressure keeping the facing
plastic sheets from separating, either at the roll itself or at
rollers assisting in the unrolling of the stock material.
After a pillow is formed, the needle is withdrawn from between the
sheets, and substantially simultaneously, another lateral seal is
formed across the area from which the needle was removed. Each seal
thus forms an inflated pillow, and the seals can be cut at
predetermined intervals to form pillow units to be placed in a
carton as dunnage.
In a particularly preferred embodiment of the invention, the stock
material has one or more centrally located longitudinal seals in
addition to the edge seals. Multiple inflation needles will then be
used, with one needle being needed to inflate a longitudinal
section. The end result is multiple longitudinal pillow units.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a first method for forming
inflated dunnage;
FIG. 2 is a plan view of a roll of plastic bags used in the first
method;
FIG. 3 is a plan view of a stock material used in a second method
for preparing inflated dunnage;
FIG. 4 is a schematic view of a second method for producing
inflated dunnage; and
FIG. 5 is a plan view of the inflated dunnage prepared by the
second method .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, the starting material of the process is a roll
10 of plastic bags, the roll comprising a backing sheet 14 and a
facing sheet 16. The roll of bags is shown in detail in FIG. 2,
each bag 12 formed from a first longitudinal seal 18, a second
longitudinal seal 20 and a lateral seal 22. Edge 24 is not sealed.
The roll of bags passes between feed rolls 30 and 32, the rolls
creating enough tension to cause a slight opening in edge 24. Air
tube 34 blows air at slightly opened edge 24, as the bag passes the
tube, causing the bag 12 to inflate. The bag then passes between
seal head 36 and seal backup 38, which places a lateral seal 40
across edge 24 of the bag. The bags then pass a separating station
44 which is activated at predetermined intervals to cut across
lateral seal 40 and form an individual sealed bag, or a unit with
multiple sealed bags.
The roll of bags 10 may be provided with lateral perforations 26 in
order to simplify the separation of the sealed bags.
This method of forming the sealed bags is highly advantageous, as
the relatively difficult job of sealing three edges of each bag is
done beforehand on a central facility which specializes in the
manufacture of plastic bags. The dunnage itself is formed on site
in only the quantity necessary and is formed with equipment which
need be capable of handling only a single roll, placing only a
lateral seal across the roll and cutting.
In an alternate embodiment of the invention, shown in FIG. 3, the
starting material is not a roll of bags, but a roll formed of a
stock material 52 sealed along longitudinal edges 52 and 56.
Lateral starting edge 54 may be sealed beforehand, or may be left
open and sealed during the process. In addition to the seals of
longitudinal edges 52 and 56, central longitudinal seals 58a, 58b,
and 58c may optionally be placed in the material, thus creating
pockets 50a, 50b, 50c and 50d.
Inflated dunnage is formed from this stock material as shown in
FIG. 4. The stock material 52 is unrolled from a roll 70 between
feed rolls 72 and 74. A seal head 76 and seal backup 78 are located
downstream of the feed rolls, and a retractable inflation needle 80
is part of the seal head.
As noted, a starting lateral edge 54 of the feed material may be
presealed, or it may be sealed in starting the process using seal
heads 76 and seal backup 78. After the formation of that seal, the
stock material continues to be unrolled, and at a predetermined
point, inflation needle 80 is extended to puncture top sheet 60 of
the stock material 52, but not puncture bottom sheet 62. Air is
blown through the inflation needle, inflating pocket 50 between
sealed edge 54 in the inflation needle, but in practice, the
inflated area extends back as far as the feed rolls. In a
substantially simultaneous manner, the needle is withdrawn, and
seal head 76 and seal backup 78 interact to form a lateral seal
across the stock material. Optionally, a perforation head 90 may be
provided just after the seal head and backup to form perforations
between the pillows as they are formed. The result is the formation
of pillows 88, and cutting station 92 is located downstream of the
sealing and inflation apparatus to cut across the lateral seals at
predetermined intervals to form pillow units which can be placed in
cartons.
When the stock material includes multiple longitudinal seals, the
result is the pillow units shown in FIG. 5, including multiple
longitudinal pillows 88a, 88b, 88c and 88d. The longitudinal pillow
units are separated by a lateral seal 54. Normally, several lateral
seals 54 will be left intact, to create a pillow unit including two
or more longitudinally attached pillow units. A multiple pillow
unit as described, including several lateral seals, is flexible
both longitudinally and laterally, and can effectively be wrapped
around a large object.
* * * * *