Note: Descriptions are shown in the official language in which they were submitted.
CASE 2899
DESCRI_I'ION
BO I L I N BAG PO UCH
05 Technical Field
The present invention relates to the packaging
of rehydratable food products in a permeable, fle~c-
ible bag which is -to be immersed in a pot of boil-
ing water. Generally after cooking, the bag is
1() removed from the pot, either 'beEore or after the
heated water is poured from the pot, and the 'bag i.5
allowed to drain either in the pot or ~hile being
suspended by some }citchen utensil such as tongs. As
will be appreciated, draining will be effected more
quickly :if t'he bag is suspended 'by its top as oppos-
ed to merely being left to drain in the pot.
'It has been found that strength of boil-in-bag
pouches made from thin permeable (e.g. mesh, perfor-
ated, retic-ulated, etc.) films of thermoplastic
20 material have a relatively low resistance to -tear-
ing. This can constitute a safety hazzard if these
bags are lifted out of a pot o~ boiling water by
means of an implement which is inserted through the
bag either by punc-turing the bag or by passing
through an aperture provided in the bag. Should the
bag tear as it is being lifted from the pot and the
bag fall back into the pot, boiling water could be
splashed onto the consumer.
~ ~l3~
The prob~Lem witll tearing bags -is of 'less c<)n-
cern for bo:i~L-in-bag pouches made from re'Lati~ely--
th:ick ancl costly ancl/or non-permeab~Le plastic Eilms.
These type pouches have previously been prov:ided
05 with fork li~t slots at: one or both ends to permit
the consumer to reaclily ancl safely remove the bag
from boiling water.
Disclosure of the Invention
_ _
This invention is directed to the use of light-
weight, economical and/or permeable films, with a
base sheet caliper of less than about 0.05 or 0.06
mm., to form into boil-in-bag pouches which are
provided with fork lift slots at one or 'bo-th ends of
the pouch. The pouch design of this invention
incorporates a wide, overlapping, longitudinal seam
in order to provide a three-ply structure in the
lift slot areas and thereby o'btain rein~orcement
against tearing in these areas.
The pouches produced in accordance with this
invention are made from a single web of heat seal-
able material using conventiona1 vertical form/fill/
seal pouch equipment which is well known to those
skilled in the art. This equipment is available
commercially from a number of sources, one being
Triangle Machine Co., Chicago, Illinois. One exam-
ple of such a unit is disclosed in U.S. Patent No.
2,145,941 to Maxfield.
The essential elements of this invention are
-the provision for a wide overlapping longitudinal
seam on the pouch, spaced-apart longitudinal seals
toward each edge of the overlapped web, and at least
one generally-horizontal aperture (e.g. slit) to 'be
used as a fork lift slot and located at one or both
ends of the pouch within -the overlapped seam and
between tlle spaced~apa-rt long:i.tud:i.na'l. seals
Typical.Ly, the di.stance between the space(l-al)art
longitudinal seals will extend ~or at 'Least 2.5~ cm,
preferably at least 3.5 cm and typically aboul: 4.5
05 cm. The horizontal aperture should be at le~st 1.9
cm in l.ength and tvpically will 'be at least ahout
3.0 cm. The fork lift slots will usually be located
above or wi.thin the transverse seals which de:Eine
the food containing chamber, -there'by avoiding any
problem of food particles passing out of the pouch
through these slots. It would o:E course 'be possible
to place the fork lift slots within the food contain-
ing chamber by burning the slot through the pouch
structure in such a manner that -the edges of the
slot are welded together.
The wide overlapped seam is sea:Led w:ith at
least two, relatively narrow, spaced-apart longitu-
dinal seals, with at least one seal at or c:Lose to
each edge o:E the overlapped web. Narrow seals are
desirable so as to preserve, a.s much as poss:ible,
the porosity of the pouch. Narrow seals are clesirw
ably made by the use of impulse or induction seal:ing
equipment which i.s known to those skilled in the art
as being par-ticularly suited for heat sealing unsup-
por-ted thermoplastic films. According to this
invention, two pairs of induction sealing bars may
be utilizecl to provide two, continuo-us, longitudinal
seals at each edge of the overlapped web. Altern-
a-tively, the seal.s may be formed by resistance
sealing bars which have a release coating.
In order to provide a we'b material having
sufficient s-tr-uctural strength to function as a
boil-in-bag pouch and to retain all of the food
prod-uc-t within the pouch, the web will typically
contain a uni.form distribution of relatively small
perforations or openings. The openings may be in
the or(ler of abo~t :L.5 mrn (().06 -in) or less with the
web hav:ing an open area of from abowt 5 to 50%,
preferably in e~cess of 20%. By means o~ this
invention, films having either reduced thickness
05 and/or increased open area may be utilized without
decreasing the tear strength of the pouch at the
fork lift sLots. A preferred embodiment of this
invention utilizes an embossed polyethylene filrn
having a base sheet thickness of abowt 0.043 mm, an
embosed film thickness of abou-t 0.5 mm and an open
area of approximately 35% comprised of about 55
holes per cm2 with each hole having a diameter of
about 0.75 mm.
The porosity oE the pouch will generally be
reduced if not eliminated in the immediate area of
the heat seal. Thus, the use of a single wide heat
seal, extending to width of the overlapped seam, is
to be avoided since the flow of water into and out
of the bag during cook:ing and draining wo-ulcl be
red-lcecl. A wide seal would also require a higher
energy input than the narrow, spaced-apart seals oE
this invention.
It would also be desirable to have the top an
bottom of each pouch sealed by means of two, narrow,
spaced-apart horizontal seals as opposed to single,
wide top and bottom seals. The horizontal apertures
or fork lift slots would be positioned between these
seals. Sealing bars for forming the -top and bottom
seals can be mounted for reciprocal motion into and
out of engagement wi-th a continuous stream of over-
lapped web material, and these bars may contain
cooling means~ such as circulating chilled water.
In this manner the seal is cooled and set prior to
the bars being opened and the risk of the seal being
pulled apart as the sealing bars are moved out of
engagement w-itll the pouch i6 redUCe(l. li would also
be possib:Le to obtain seals at the top and bottom
eclge o:E each pouch by usirlg a hot wire cwtof~ be-
tween pouches.
05 The boi.1 in bag pouch of th:is invention is inost
suitable for partic~llate, dried food rrlaterial which
is to be rehyclrated during cooking. Such materials
as uncooked or partially-cooked rice, pasta, dried
beans, lentils and the like, may be used in conjunc-
tion with the pouch of this inven-tion.
Description of Drawings
Fig. 1 depicts the method of Eorming the boil-
in-bag pouch of this invention, clearly illustrating
the formation of the wide, overlapped, ].ongitudinal
seam .
Fig. 2 depicts a specific embodiinent o-E the
boil-in-'bag pouch of this invention illwstrating two
narrow spaced-apart, longitudinal seals as well as
two, narrow, spaced apart transverse seals at both
the top and 'bottom ends of the powch.
Best Mode :Eor Carrying Out the Tnvention
As shown in Fig. 1 a single we'b (l) of a per-
merable heat sealable material is drawn around aforming/filling tube (2) in a manner such that the
edges of the web (3 and ~) are overlapped and form a
two-ply region (5) e~tending in the logitudinal
direction. The edges of the overlapped web are then
heat-sealed to the web by means of a conventional
heated rolls or parallel impul.se sealing bars (not
shown). Fig. 1 also clepicts the completed bottom
end of a pouch consisting of two, spaced apart
transverse heat seals (6 and 7) which could be
conveniently made by two sets of parallel sealing
- 6 -
bars. A~ls0 shown i.n this f:igwre :is a fork :litt slot
(8) positioned between the spaced-apart longituclinal
seals so that the slot -is Eorrned tllrough three pl.ys
of the web mater:ial.
05 Fig. 2 depicts a completed boil-:in-bag pouch
showing spaced apart traverse seals at both the top
(9, 10) and bottom (6,7) of the bag as well as two
spaced apart longitudinal heat seals (12,13) which
form the wide ove-r].apped seam of the invention. In
operation, as will be appreciated by those skilled
in the ar-t, the bottom seals (6,7) and bottom fork
lift slot (8) of one pouch can be formed at the same
time the top seals (9,10) and top fork lift opening
(11) are being formed in a lower adjacent pouch.
Severing of the pouches from each other may also be
effected at this time. ~s earlier noted, :in lieu o:E
end seals positi.oned at 7 and 9, it would be possi-
ble to simultaneously obtain seals at the to~p and
bottom edges of adjacent bags and sever adjacent
bags by pass:i.ng a hot wire between two acljacent
pouches. ~s is wel1 known to those skilled in the
art, the form/fill/seal sequence used in the process
of this invention proceeds with at least one bottom
seal being formed in each consecutive pouch prio:r to
the pouch receiving the food product from tube (2)
and thereafter at least one top seal is formed. The
spaced-apart longitudinal seals are formed continu-
ously as the web material passes suitable sealing
means.
Having thus described the invention, what is
claimed is:
