... for trash, produce, food storage, utility, sandwich ... in singles, wickets, etc. and rolls
The bags on this site are protected by PCT patent application
WO 0249928 and related filings.
Contact SNAP Film Technologies <mailATsnapopenDOTcom> to
discuss licensing.
A flat bag is one with a front panel, a back panel, and no gussets or additional folds.
Xbag™ is easily applicable to side-welded flat bags. In this process the bags travel sideways during the making process (this mode converts either a slit- or split-tube into either one or two rows of individual bags; not all flat bags are made this way, but most are). Adaptation for Xbag™ is simple.
At
right: Plan view of process for making SNAP™ flat bags of side-weld type.
Punches are a simple way to create reveals. Reveals need not be circular, in
fact a
rounded rectangle might be preferable -- and very stretchy plastics might benefit
from longer reveals.
The layout shown is a typical one. All that has been added are top and bottom punches that are offset by one bag width. In this example they are operated simultaneously each second advance; meanwhile, on each advance two welds and a cut (or perforation) are made. Of course, the front panels are guided between the jaws of one punch and the rear panels are quided between the jaws of the other.
Alternatively, punches could be together and not offset, but then they would have to operate alternately, one punch with each first advance, the other for each second advance (otherwise the reveals would coincide and the SNAP™ feature would be defeated).
Advancing and punching: the folded sheet is advanced as usual one bag at a time for welding and cutting, but on one advance the front sheet is punched (overlapping where the welds and cuts will be) and on the next the rear sheet is punched. Alternatively, a pair of punches, one for the front sheet and one for the back, can be arranged one bag width apart and operated simultaneously on each second advance.
Conventionally, a large flat bag 700 is formed from a U-shaped panel, or a flattened slit tube, from which bag sides are formed by welds 704 and bags separated by cuts 705. To make SNAP™ bags alternating reveals or weakenings are made in the free edge of the slit tube stock. A reveal 706 in the front panel is complementary to the reveal 707 in the rear panel; grasping the bag in these areas permits shearing of front and rear panels against each other thus disrupting interlayer cling and rendering the bag readily openable.
At right is a perspective view of process for making SNAP™ flat bags
of side-weld
type.
In the perspective visualisation three bags (labelled 1,2,3) are shown in the process of punching. Sealing
and cutting complete the bag following punching, and then folding and packaging
can be done as normal.
The bags could also be made from multiple strips of a
wide tube, in which case the bag bottom is also a weld, but the side welds would
be the last ones made.
Although bags commonly are detached from each other at this point, they can also be put on rolls; the bags will be connected side-to-side and the openings will be along one edge of the roll (see below).
The SNAP™ improvement can be made with a simple addition to existing process lines: a pair of punches, or any device to make a localised void or weakening in a single layer.
These bags are easy to make with small change to standard slit- or split-tube manufacturing lines.
The procedure creates a bag in which reveals expose graspable points, each addressing one sidewall. That allows the user to grasp at the reveals created by the punches, usually about half a thumb length or 3 to 5 cm in from each side, and tug lightly within the plane of the bag. This tiny but highly efficient motion instantly shears the front and back panels against each other and disrupts the interlayer cling.
"How does it
work"? Purely mechanically, via the special architecture. The Xbag™ has
alternating (one at left front, one at right rear, etc.) reveals
or weakenings near the top edges. The grip holes™ show top-of-bag
and where-to-grip. That lets you grip the front and back independently
and, with a light tug, shear them against one another for the entire distance
between the grasping points; this breaks the interlayer cling and the bag
is open.
Shown in cross section of top of bag: "grasping points" are where you can grip just one panel, and there's one for the front and one for the back, so a light tug pulls them in opposite directions, opening the bag. They work like the "edge strips™" of a Zbag. "Grip holes" show where to grip (where grasping points are), and show which end is top.
We recommend that Licensees also punch grip holes™ in
the portions exposed by the reveals (#706, 707 etc.
in the diagram), as an indication to the user of where to grip and
tug. (These indicia are a trademark and Licensees
can exploit it in advertising or promotion, to increase both customer comfort
and product
recognition.)
A
note
on
the
package
of
economy
garden
bags (no printing on the bags)
would include this graphic:
 |
Supermarkets in North America traditionally have liked flat bags on rolls. Up to now however, these have been prone to difficulty (intermittent to regular depending on brand and user) in opening.
Roll flat bags as most commonly seen are connected end-to-end. This is clearly not a requirement, as can be seen from the fact that large flat bags are often made FROM a folded sheet and (before cutting) the 'imaginary' bags-to-be are joined side-to-side. Flat bags can therefore be made in a side-to-side series, with the mouths at the side of the roll. Instead of cutting, you perforate. This allows Xbags to be used, to bring ease-of-use to flat produce bags and other flat bags commonly supplied on rolls.
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Xbags can be single (as normal for many flat bags), BUT can also be issued on rolls/PTO (PerforatedTearOff). Roll bags with
side-to-side arrangement. |
