Method for manufacturing stackable plastic handle bags with releasable adhesive

A handle bag 16 in a bag pack 2 suitable for suspension and opening on a bag rack 4 has a front wall 22, a rear wall 24, a pair of laterally spaced handles 20, and an area of a cold releasable adhesive 8 between the rear wall 24 of the bag 16 and the front wall 42 of its immediately subsequent bag 40. The front wall 22 is joined opposite the rear wall 24 and defines an enclosure 26 having an open top 28, opposed two sides 30 and a bottom 32. The handles 20 and the opposed sides 30 are substantially symmetric with respect to a longitudinal axis 50. The area of the cold releasable adhesive 8 is centered about the longitudinal axis 50 and is positioned closer to the open top 28 than to the bottom 32. The area of the cold releasable adhesive 8 is preferably in the range of about 1 sq. inch to about 4 sq. inches. The cold releasable adhesive 8 is preferably a water-based adhesive with a relatively high water volume content prior to application, and it is preferred that the adhesive 8 produce a relatively small peel strength and a relatively high shear strength between the bag walls 24 and 42 after it dries.

BACKGROUND 
The present invention relates to a pack of stackable plastic handle bags, 
commonly referred to as T-shirt bags, and in particular to a pack of 
stackable plastic handle bags with releasable adhesives between the bags 
to form the bag pack. 
The use of plastic shopping bags in grocery stores, supermarkets, 
department stores and other stores is well known. To expedite the bagging 
process, individual plastic bags neatly stacked in a bag pack for 
suspension on a conventional bag rack are commonly used. 
A conventional bag rack generally includes two substantially parallel, 
outwardly extending, laterally spaced support arms and a center hook 
supporting the bags in the bag pack. The individual bags have laterally 
spaced handles with handle apertures extending therethrough for receiving 
the support arms and a removable center mount for receiving the center 
hook. Pin welds can optionally be used to hold the individual bags 
together in the bag pack. 
In operation, the bag pack is supported by the bag rack by suspending the 
bag handles on the support arms and attaching the center mount onto the 
center hook. A bagger, such as a store cashier, prepares a bag for loading 
by pulling a front wall of the front bag in the bag pack away from the bag 
pack, thereby separating the front wall from the center mount and the 
center hook. In this position, the support arms which extend through the 
handle apertures support the bag during loading. When the loading is 
completed, the bag is removed from the support arms and the bag 
immediately subsequent to the removed bag is pulled open on the support 
arms by the bagger. 
The pin welds which are used in some conventional bagging systems to hold 
the bags in the bag pack sometimes cause the individual bags difficult to 
separate. Static charge between the individual plastic bags sometimes 
accumulates to cause the bags to attract and stick to each other. 
Therefore, the bagger's time is wasted grappling for the next bag. 
Accordingly, to expedite the bagging process, it has become important to 
make each subsequent individual bag in the bag pack open upon removal of 
the previous bag. 
In an attempt to solve this problem, other conventional bag packs have been 
designed by attaching the rear wall of each individual bag in the bag pack 
to the front wall of the immediately subsequent bag in the bag pack. Thus, 
when a bag is removed from the bag rack, the subsequent bag is opened on 
the bag rack. In one approach, a small area of an adhesive is used to 
attach the rear wall of each bag to the front wall of its immediately 
subsequent bag. However, this approach has had limited success since the 
adhesive often does not easily disengage, causing a plurality of 
subsequent bags to be pulled off the bag rack before the adhesive bond is 
broken, or the adhesive bond breaks prior to the next bag being opened on 
the bag rack. 
Another type of conventional bag pack uses a hot melt adhesive between the 
walls of the individual plastic bags in the bag pack. The hot melt 
adhesive is applied in a small spot area on the walls of each bag. Because 
of the high peel strength of the hot melt adhesive, when a bag is removed 
from the bag rack it cannot be easily separated from its immediately 
subsequent bag. Because the hot melt adhesive is strong, one hand may be 
required to hold the subsequent bags in the bag pack while the other hand 
pulls the first bag away from the bag pack. 
Another bag pack design, disclosed in U.S. Pat. No. 5,469,970, issued to 
Nam T. Li, the inventor of the present invention, uses an adhesive between 
the rear wall of each bag and the front wall of its immediately subsequent 
bag in the bag pack in an area offset from the center of the bag. While 
the bags in the bag pack are relatively easy to open, the area of the 
opening of each bag is limited by the offset adhesion of the back wall to 
the front wall to the front wall of its immediately subsequent bag. In 
some applications, it is inconvenient for the bagger to place large items 
into the bag through the limited openings offered by the offset adhesion 
of the bag. 
Therefore, there is presently a need for a convenient and reliable bag pack 
system to allow the bagger to open each individual bag in the bag pack 
with a sufficiently large opening while causing its immediately subsequent 
bag to be opened individually upon removal of the immediately preceding 
bag from the rack. 
SUMMARY OF THE INVENTION 
The present invention satisfies these needs. In view of the above problems, 
the present invention provides a stackable handle bag with a cold 
releasable adhesive in a relatively large area on the bag walls centered 
about the longitudinal axis of the bag. In one embodiment, the stackable 
handle bag generally comprises: 
(a) a front wall having a longitudinal axis; 
(b) a rear wall having a longitudinal axis coinciding with the longitudinal 
axis of the front wall, the rear wall joined opposite the front wall 
defining an enclosure having an open top, opposed sides and a bottom; 
(c) a pair of laterally spaced handles integral with the front and rear 
walls extending upwardly from the open top, each handle having a handle 
aperture extending therethrough for receiving one of the support arms of 
the bag rack; 
(d) a releasable center mount attached to the front and rear walls on the 
longitudinal axis of the walls adjacent the open top for receiving the 
center hook of the bag rack, the center mount releasably supporting the 
bag; and 
(e) an area of a cold releasable adhesive on the rear wall, the area of the 
cold releasable adhesive substantially centered about the longitudinal 
axis and positioned closer to the open top than to the bottom, the cold 
releasable adhesive adapted to releasably adhere to the front wall of the 
immediately subsequent bag, the area of the cold releasable adhesive 
sufficiently large so that the force required to release the cold 
releasable adhesive is greater than the force required to release the 
center mount when the front wall is pulled from the back wall of the same 
bag, and when the bag is removed from the bag rack by its handles, the 
force required to release the cold releasable adhesive is less than the 
force required to continue to pull the immediately subsequent bag out of 
the bag rack. 
The present invention also provides a bag pack of stackable bags suitable 
for suspension by laterally spaced support arms and a center hook of a bag 
rack, the bag pack comprising: 
(a) a plurality of aligned stackable bags, each bag comprising: 
(i) a front wall having a longitudinal axis; 
(ii) a rear wall having a longitudinal axis coinciding with the 
longitudinal axis of the front wall, the rear wall joined opposite the 
front wall defining an enclosure having an open top, opposed sides and a 
bottom; 
(iii) a pair of laterally spaced handles integral with the front and rear 
walls extending upwardly from the open top, each handle having a handle 
aperture extending therethrough for receiving one of the support arms of 
the bag rack; 
(iv) a releasable center mount attached to the front and rear walls on the 
longitudinal axis of the walls adjacent the open top for receiving the 
center hook of the bag rack, the center mount releasably supporting the 
bag; and 
(b) an area of a cold releasable adhesive on the rear wall of each bag and 
on the front wall of each immediately subsequently bag in the bag pack, 
the area of the cold releasable adhesive substantially centered about the 
longitudinal axis and positioned closer to the open top than to the 
bottom, the cold releasable adhesive adaptive to releasably adhere to the 
rear wall of each bag with the front wall of each immediately subsequent 
bag in the bag pack, the area of the cold releasable adhesive sufficiently 
large so that the force required to release the cold releasable adhesive 
is greater than the force required to release the center mount when the 
front wall is pulled from the back wall of the same bag, and when the bag 
is removed from the bag rack by its handles, the force required to release 
the cold releasable adhesive is less than the force required to continue 
to pull the immediately subsequent bag out of the bag rack. 
Preferably, the cold releasable adhesive is water-based with about 60% 
water by volume prior to application on the bags to provide the necessary 
adhesive force. It is further preferred that the area of the cold 
releasable adhesive be relatively large, for example, in the range of 
about 1 sq. inch to about 4 sq. inches. For ease of manufacturing, the 
area of the cold releasable adhesive can be of an approximately circular 
shape with a diameter of about 2 inches when the bags are stacked together 
in the bag pack. 
Advantageously, the area of the cold releasable adhesive is positioned on 
the bag walls below the center mount and closer to the open top than to 
the bottom, and centered about the longitudinal axis of the bags. When a 
bag is pulled open, the opening of the bag is much larger than the type of 
bag which is adhered to its subsequent bag by an area of adhesive offset 
from the longitudinal axis of the bags. Moreover, because the adhesive 
used occupies a relatively large area with a relatively small peel 
strength per unit area, the walls of the opened bag and of the immediately 
subsequent bag retain their integrity when they are pulled apart from each 
other, thereby avoiding tearing the bag walls when the opened bag is 
removed from the bag rack.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention provides a handle bag in a bag pack with a relatively 
large area of a cold releasable adhesive between walls of adjacent bags in 
the bag pack that is suitable for suspension by a bag rack with laterally 
spaced support arms and a center hook. Specifically, each bag in the bag 
pack is substantially symmetric about a longitudinal axis, and the area of 
the cold releasable adhesive is substantially centered about the 
longitudinal axis of the bag. When a bag is pulled from the bag rack by 
its handles, the force required to release the cold releasable adhesive is 
less than the force required to continue to pull its immediately 
subsequent bag out of the bag rack. Detailed descriptions of preferred 
embodiments of the present invention are described as follows: 
FIG. 1 is a perspective view of a bag pack 2 in accordance with the present 
invention mounted on a conventional bag rack 4. The bag pack 2 according 
to the present invention comprises a plurality of aligned individually 
stackable handle bags 6, commonly known as T-shirt bags, with an area of a 
releasable adhesive 8 between the individual bags. 
The bag pack 2 is mounted on the bag rack 4, which typically comprises a 
frame 10 having a pair of laterally spaced, outwardly extending support 
arms 12. The bag rack 4 typically further includes a center hook 14 
centered between the support arms 12. The center hook 14 is also generally 
supported by the frame 10 of the bag rack 4. The bag rack 4 is well known 
in the industry, and it is described in further detail in U.S. Pat. No. 
Re. 33,264, issued to Baxley, et al., and U.S. Pat. No. 5,074,674, issued 
to Kuklies, et al. 
FIG. 2 shows a perspective view of the bag pack 2 of FIG. 1 with a bag 16 
in the bag pack 2 immediately facing a bagger (not shown) opened by the 
hands 18 of the bagger while the bag 16 is suspended on the support arms 
12 of the bag rack 4. The bag 16, which is identical to other bags 6 in 
the bag pack 2, has a front wall 22 and a rear wall 24 which is joined 
opposite the front wall 22 to define a bag enclosure 26 having an open top 
28 and closed opposed sides 30 and a bottom 32. The bag 16 also includes a 
pair of laterally spaced handles 20 integral with the front and rear walls 
22 and 24 extending upwardly from the open top 28, each handle having at 
least one handle aperture 32 that is sized to fit one of the support arms 
12 of the bag rack 4. The support arms 12 of the bag rack 4 extend through 
the handle apertures 32 of individual bags 6 in the bag pack 2, and 
support the weight of the bag pack 2 as well as any items (not shown) 
placed in the opened bag 16. 
When the bag pack 2 is mounted on a bag rack 4 with a center hook 14, a 
center mount 34 is preferably provided at the open top 28 of each 
individual bag in the bag pack 2 for attachment onto the center hook 14 of 
the bag rack 4. The center hook 14 of the bag rack 4 preferably holds the 
center mounts 34 of the bags 6 in the bag pack 2 to provide additional 
weight support for the bags 6. As shown in the drawings, the center mount 
34 can be a detachable tab as described in U.S. Pat. No. Re. 33,264, 
having a mount aperture 36 for receiving the center hook 14 and a lower 
aperture 38 to facilitate detachment of bags from the center mount 34 when 
the bags are individually pulled from the bag rack 4. Alternatively, the 
center mount 34 can be an aperture or slit as described in U.S. Pat. No. 
5,074,674. The entire bag pack 2 is supported at these three positions, 
namely, the two support arms 12 and the center hook 14. 
When the bag 16 in the bag pack 2 immediately facing the bagger is pulled 
to open, the lower aperture 38 of the center mount 34 of the bag 16 is 
broken, thereby separating the bag 16 from the center hook 14 of the bag 
rack 4. During the opening process, the front wall 22 of the bag 16 is 
separated from its rear wall 24, and the bag handles 20 are separated from 
the other bags 6 in the bag pack 2 but are still suspended by the support 
arms 12 of the bag rack 4. Bag 40, which is immediately subsequent to the 
bag 16 in the bag pack 2, has a front wall 42 that is connected to the 
rear wall 24 of the bag 16 at the area of the releasable adhesive 8 while 
the bag 16 is being pulled open on the bag rack 4. 
Advantageously, since the area of the releasable adhesive 8 is 
substantially centered between the bag handles 20 and positioned between 
the rear wall 24 of the bag 16 and the front wall 42 of the immediately 
subsequent bag 40 below the open top 28, the area of opening at the open 
top 28 of the bag 16 can be large when the bag 16 is opened on the bag 
rack 4 as shown in FIG. 2, thereby conveniently accommodating items with 
relatively large dimensions when they are placed into the bag 16. 
FIG. 3 is a perspective view of the bag pack of FIGS. 1 and 2 showing the 
bag 16 immediately facing the bagger being removed from the bag pack 2 and 
the immediately subsequent bag 40 being pulled open by the releasable 
adhesive 8, thereby making the subsequent bag 40 ready for loading. The 
handles 20 of the bag 16 are removed from the support arms 12 of the bag 
rack 4 at this time, and the rear wall 24 of the bag 16, while still 
connected to the front wall 42 of the immediately subsequent bag 40 at the 
area of the releasable adhesive 8, is being peeled off from it while the 
bag 16 is pulled further away from the bag rack 4. When the front wall 42 
of the immediately subsequent bag 40 is pulled away from the rear wall 44 
by the pulling force applied to the adhesive 8, an opening 46 is formed 
between the front and rear walls 42 and 44 of the immediately subsequent 
bag 40. Bag handles 48 of the immediately subsequent bag 40 may also be 
moved partially forward on the support arms 12 of the bag rack 4. 
Therefore, the immediately subsequent bag 40 is ready for loading from the 
opening 46 as soon as the bag 16 is detached from the bag 40. 
FIG. 4 is a front view of a bag 6 in the bag pack 2 of FIG. 1 prior to 
being mounted on the bag rack 4. The bag 6 has sealed opposed sides 30, a 
sealed bottom 32, and an unsealed open top 28 at which the front wall is 
separated from the rear wall when the bag 6 is pulled from the bag rack 4, 
as shown in FIGS. 2 and 3. The bag handles 20 and opposed sides 30 are 
substantially symmetric with respect to a longitudinal axis 50. A center 
mount 34, which is preferably a detachable tab at the center of the open 
top 28 of the bag 6 for attachment to the center hook 14 of the bag rack 
4, is centered about the longitudinal axis 50 of the bag 6. As described 
above, the center mount 34 can include a mount aperture 36 for receiving 
the center hook 14 and a lower aperture 38 that is detachable when the bag 
6 is pulled forward. The bag handles 20 each have a handle aperture 32 
that is sized to fit one of the support arms 12 of the bag rack 4 as shown 
in FIGS. 1-3. 
A releasable adhesive 8 is positioned on the walls of each bag so that the 
adjacent bags releasably adhere to each other in the bag pack 2. The area 
of the releasable adhesive is substantially centered about the 
longitudinal axis 50 of the bag 6, on the bag wall closer to the open top 
28 than to the bottom 32. It is preferred that the area of the releasable 
adhesive 8 be positioned below the center mount 34, which is centered 
about the same longitudinal axis 50. 
The bags 6 are preferably light weight, highly flexible, and strong 
thermoplastic material and are fabricated from a continuous plastic tube 
gusseted, flattened, and heat sealed at opposed upper and lower ends. The 
open top 28 of the bag 6 is formed by a cutout inwardly and centrally 
through the upper portion of the bag 6. This cutout defines the center 
mount 34 and the pair of laterally spaced handles 20 formed in the 
upwardly extending portions of the front and rear walls 22 and 24 of the 
bag 6, respectively. Additionally, the sides 30 can be pleated (not shown) 
or the bottom 32 can be pleated (not shown). The methods of sealing the 
front and rear walls 22 and 24 of the bag 6 at the opposed sides 30, the 
bottom 32 and the handles 20 are well known to a person skilled in the art 
and are not critical to the present invention. 
The releasable adhesive 8 is preferably an adhesive that has a high shear 
strength but a low peel strength on plastic, and a low viscosity allowing 
for ease of application and relatively even distribution of the adhesive 
between the bags 6 in the area centered about the longitudinal axis 50 to 
which the adhesive 8 is to be applied. It is preferred that the releasable 
adhesive 8 be a cold releasable adhesive, that is, an adhesive with a 
relatively poor peel strength which need not be heated to lower its 
viscosity prior to application to the plastic bag walls. The cold 
releasable adhesive is preferably water-based with a slow rate of drying 
in room temperature to allow the adhesive to be placed between the bags 
without distorting the wall surfaces of the bags. For example, the 
releasable adhesive 8 can be a water-based cold adhesive, such as 
Aqualock.TM. 8003 brand adhesive, manufactured by BF Goodrich, Adhesive 
Systems Division, 123 West Bartges Street, Akron, Ohio 44311-1081. 
Typically, the Aqualock.TM. 8003 brand adhesive is about 35% water by 
volume in a condensed form prior to application. The Aqualock.TM. 8003 
brand adhesive takes about 12 hours to dry and is non-flammable, non-toxic 
and pressure sensitive. 
The physical properties of the Aqualock.TM. 8003 brand adhesive are as 
follows: 
Base: acrylic 
Color: white 
Total solids: 65% 
Solvents: none--only water 
Thinner: water 
Weight/gallon: 8.5 lb./gallon (1.02 kg/liter) 
Calculated coverage: 1,000 SF/Gal/Mil (24 m.sup.2 /liter/0.254 mm) 
Flashpoint: none 
Viscosity: 900-1800 cps & 3Brkfd at 20 rpm 
pH: 7-8 
Precautions: Do not freeze. 
The size and the shape of the area of the cold releasable adhesive 8 varies 
according to the type of the adhesive used, the viscosity of the adhesive, 
and desired peel strength relative to the shear strength. For the 
Aqualock.TM. 8003 brand adhesive or a water-based cold adhesive with 
properties similar to it, the area of the adhesive 8 is preferably in the 
range of approximately 1 sq. inch to approximately 4 sq. inches. In a 
typical manufacturing process in which the adhesive is applied to the bag 
surfaces by a nozzle, the shape of the area of the adhesive 8 when the 
individual bags 6 are pressed together to form the bag pack 2 is 
approximately circular. The diameter of the approximately circularly 
shaped area of cold releasable adhesive 8 is preferably on the order of 
about 2 inches. It is preferred that the area of the cold releasable 
adhesive 8 be relatively large, typically between 1 sq. inch and 4 sq. 
inches, because for a given adhesive, large areas of adhesive have higher 
shear strength than smaller areas of adhesive. On the other hand, the peel 
strength per unit area remains the same. Therefore, when the rear wall 24 
of the bag 16 is peeled away from the front wall 42 of the immediately 
subsequent bag 40 in FIG. 3, the peeling force is not excessively large to 
cause tearing of either bag wall 24 or 42. The shear strength of the cold 
releasable adhesive 8 is preferably much larger than its peel strength. 
Optimally, water is added to dilute the Aqualock.TM. 8003 brand adhesive 
until the percentage is approximately 60% to 90% water by volume prior to 
application to the bag walls. With a high water content of about 60% to 
90% by volume, the adhesive dries slowly and its viscosity is low. An 
advantage of a low viscosity adhesive is that when it dries on the bag 
walls after application, it produces a small peel strength compared to its 
shear strength. 
FIGS. 8a and 8b are simplified side and front views, respectively, of an 
embodiment of a machine that manufactures the bag pack 2 in accordance 
with the present invention. The cold releasable adhesive can be applied to 
the bag walls of the bag pack 2 through a nozzle 70 in FIGS. 8a and 8b or 
a sponge (not shown). In some applications, a nozzle is preferred over a 
sponge because the sponge may have to be changed often to prevent jamming 
the bag manufacturing equipment by the adhesive built up in the sponge. 
The nozzle or sponge is preferably connected to a fixed flow pump 72, 
which supplies the adhesive to the nozzle or sponge at a substantially 
fixed rate from a bottle 74 or a reservoir (not shown) that stores the 
cold releasable adhesive 76 in liquid form. An example of the pump 72 
suitable for transferring the adhesive 76 is a Masterflex.RTM. L/S.TM. 
Easy-Load.RTM. pump head, manufactured by Barnant Company, 28W092 
Commercial Avenue, Barrington, Ill. 60010-2392. The nozzle 70 is attached 
to a moveable lever 78 which moves upward and away from the bag pack 2 
each time a bag is fed from bag manufacturing equipment 80 to a bag pack 
holder 82, which holds the bag pack while the nozzle 70 applies the 
adhesive 76 to the bag walls. When a bag 84 comes to a stop on the bag 
pack 2 resting on the holder 82, the lever 78 moves downward, and the 
nozzle 70 drops the adhesive 76 onto the bag 84, to form an area of the 
adhesive 8 on the bag wall substantially centered about the longitudinal 
axis 50 of the bag, the front view of which is shown in FIG. 4. The 
quantity of the adhesive dropped onto each bag is determined by the flow 
rate of the pump 72. FIGS. 8a and 8b illustrate only one embodiment of 
making the bag pack in accordance with the present invention; other 
embodiments are also feasible. 
The operation of opening the bag 16 and pulling it away from the bag pack 2 
in the preferred embodiment in which a relatively large area of cold 
releasable adhesive 8 produces a shear strength much larger than its peel 
strength is illustrated in FIGS. 5a, 5b, 6a, 6b, 7a and 7b. In FIG. 5a, 
the bag 16 is opened while the bag handles 20 are still suspended by the 
support arms 12 of the bag rack 4. The front wall 22 of the bag 16 is 
detached from the center mount 34, which is held by the center hook 14 of 
the bag rack 4. The bag enclosure 26 is opened at the open top 28 when the 
front wall 22 is separated from the rear wall 24 of the bag 16. At this 
time, the rear wall 24 of the bag 16 remains attached to the center mount 
34 of the bag pack 2. The pulling force indicated by arrow 54 in FIG. 5b 
is substantially tangential to the surface of the rear wall 24 of the bag 
16. The lower aperture 38 of the center mount 34, which is preferably a 
slit opening adapted to facilitate the detachment of the bag 16 from the 
center mount 34 upon application of a sufficiently large pulling force 54, 
is not broken when the bag handles 20 remain suspended on the support arms 
12 of the bag rack 4 with the bag 16 ready for loading from the open top 
28. When the rear wall 24 of the bag 16 is still attached to the center 
mount 34 fixed to the center hook 14 of the bag rack 4, the support arms 
12 and the center hook 14 of the bag rack 4 support the weight of the 
items (not shown) placed into the bag 16 at the bag handles 20 and the 
center mount 34 of the bag 16, respectively. 
FIGS. 6a and 6b show the process of pulling the bag 16 further away from 
the bag pack 2, typically after the bag 16 is loaded. At this time, the 
rear wall 24 of the bag 16 and the front wall 42 of the immediately 
subsequent bag 40, attached together by the adhesive 8, are separated from 
the center mount 34 when the lower aperture 38 is broken. The pulling 
force indicated by an arrow 56 is larger than the force 54 illustrated in 
FIG. 5b, but is still substantially tangential to the surface of the rear 
wall 24 of the bag 16. Because the shear strength of the adhesive 8 is 
much larger than its peel strength, the front wall 42 of the immediately 
subsequent bag 40 remains attached to the rear wall 24 of the bag 16. When 
the front wall 42 of the immediately subsequently bag 40 is detached from 
the center mount 34 by the pulling force 56, an opening 46 is formed 
between the front and rear walls 42 and 44 of the immediately subsequent 
bag 40. 
FIGS. 7a and 7b are perspective and sectional views, respectively, 
illustrating the opening of the immediately subsequent bag 40 when the bag 
16 is removed from the bag rack 4 and the rear wall 24 of the bag 16 is 
peeled off from the front wall 42 of the immediately subsequent bag 40 at 
the area of the cold releasable adhesive 8. At this time, the pulling 
force indicated by an arrow 58 is no longer tangential to the surface 
portion 60 of the rear wall 24 of the bag 16 to which the cold releasable 
adhesive 8 is attached. The pulling force 58 has a normal vector component 
62 which is substantially perpendicular to the surface portion 60 of the 
rear wall 24 of the bag 16. Therefore, the pulling force 58 acts upon the 
surface portion 60 as a peeling force to release the rear wall 24 of the 
bag 16 from the front wall 42 of the immediately subsequent bag 40. Since 
the peel strength of the cold releasable adhesive 8 is much weaker than 
its shear strength, it is relatively easy to peel the rear wall 24 of the 
bag 16 from the front wall 42 of the immediately subsequent bag 40 when 
the pulling force 58 has a normal vector component 62 that is 
substantially perpendicular the area of the cold releasable adhesive 8 in 
a direction that causes the rear wall 24 of the bag 16 to move away from 
the immediately subsequent bag 40. 
While the rear wall 24 of the bag 16 is being peeled off from the front 
wall 42 of the bag 40, the opening 46 of the immediately subsequent bag 40 
becomes wider and wider since the front wall 42 is further separated from 
the rear wall 44 of the immediately subsequent bag 40 by the pulling force 
58. When the rear wall 24 of the bag 16 is completely detached from the 
front wall 42 of the immediately subsequent bag 40, the opening 46 of the 
immediately subsequent bag 40 is sufficiently large for loading on the bag 
rack 4. 
After the bag 40 is loaded and removed from the bag rack 4 in a manner 
similar to the bag 16, bags subsequent to the bag 40 in the bag pack 2 can 
be loaded and removed from the bag rack 4 sequentially in the same manner 
as for bags 16 and 40. With a large opening formed in a subsequent bag 
when its immediately preceding bag is pulled from the bag rack, the need 
for the bagger to clear the opening for the subsequent bag is obviated, 
thereby expediting the bagging process. 
Although the present invention has been described in considerable detail 
with reference to certain preferred versions thereof, other versions are 
possible. It is intended to cover all modifications, alternatives and 
equivalents which may fall within the spirit and scope of the invention as 
defined in the appended claims.