Note: Descriptions are shown in the official language in which they were submitted.
METHOI) AND APPARATUS EOR PACKAGING A
COMPE~ESSIBLE TEXTILE PRODUCT, AND
THE~ RESULTING PACKAGE
The ~resent invention relates to a method and
apparatus for compacting and packaging bulky textile pro~
ducts to substantially reduce their bulk and thereby
facilitate shipment and storage, and to the resulting
package.
Prior attempts to compact bulky textile pro-
ducts, such as compres.sible consumer textile products and
bulk fiber packages, to facilitate their shipment and
storage, have not met wiih rull commercial acceptance
s.ince many such products develop semi-permanent or even
permanent wrinkles or creases or a permanent fiber
compression set/ after a period of time in a compacted
condition. ~uch wrinkles, ~reases, or compression set of
the ~ibers can render the product unsuitable for consumer
sale or other intended use. To alleviate this probleml it
has been proposed to initially reduce the moisture Gontent
in consumer textile products, and then enclose them in
moisture impermeable packages which may thereafter be eva
cuated to reduce their bulk~ More particularly, in the
prior U. SO patents to Shishoo, Nos. 3~961r458 and
4,199,916, it is proposed that the moisture content be
reduced by exposing the textile material to a conditioning
environment having a low relative humidity for an extended
period of time, and thereafter vacuum packaging the
materialO In khe '916 patent, it is suggested that the
conditioning may be conducte,d by passing the textile
material through an elongate tunnel, which includes an
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initial treatment zone wherein the conditioning air is
maintained at 20-30~4 C and 15-30% relative humidity, and a
subsequent stabilization zone wherein the conditioning air
is maintained at 15-20~ C and 5-12% relative humidity.
The treatment time in the tunnel is necessarily long in
order to permit the moisture level in the textile
fabric to reach an equilibrium with the relative humi-
dity of the conditioning air, and it is indicated in
the patent that up to 240 minutes may be required.
As will be apparent, the processes disclosed
in the two above Shishoo patents are not totally satis-
factory from a,commercial point of view, since an
extended treatment time is required, which substan-
tially limits the production capacity. Further,
substantial energy, space, and equipment are required
to control the temperature of the conditioning air, as
well as to lower the relative humidity of such air to
the required low levelsO Still further, the textile
products must be treated in an open unfolded condition,
and it is not realistically possible to obtain very low
moisture levels in the textile products, such as below
- 10% of its norrnal content, since an exor~itant con-
ditioning time in air of extremely low relative humi-
dity would be requiredO
It is accordingly an object of the present
invention to provide a commercially viable method and
apparatus for packaging textile products under com-
pacted conditions to thereby reduce their bulk and thus
facilitate handling, shipment and stora~e.
It is a more particular object of the presen~
invention to provide a method and apparatus for
packaging textile products under compacted conditions,
and wherein the textile product is characteri~ed by the
substantial absence o permanent wrinkle~, creases or
fiber compression set upon opening of the package.
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Xt is also an object of the present invention
to provide a method and apparatus of the described
type~ and wherein substantially all of the moisture in
the textile product may be removed to thereby maximize
the beneficial results achieved by the absence of
moisture, and while requiring only a short time and
utilizing relatively low levels of energy and limited
processing space.
It is still another ob~ect of the present
invention to provide a package of a compressible tex-
tile product, and where~irl t'ne material is compressed to.
at least about 50% of its natural volume, and has a
moisture content of not more than about 10~ of its nor
mal content.
These and other objects and advantages of the
present invention are achieved in the embodiment
illustrated herein by the provision of a method and
apparatus which inclu~es the steps of drying the tex-
tile product by applying microwave energy thereto at an 20 energy level and for a t.ime sufficient to vaporize at
least a substantial portion, and preferably substan-
tially all, of the ambient moisture therein, and then
promptly compressing the textile product and packaging
the compressed product in an essentially vapor imper-
meable enclosure which mainta.ins the compressed con-
dition thereof. Preferably, heated ambient air is
passed across the surface of the textile product during
the drying step, to facilitate the removal of the
vapori7.ed moisture from the textile product and ~hereby
speed the drying process.
The use of microwave energy to vaporize the
moisture in the textil.e material in accordance with the
present invention has been found to result in sevexal
surprising and significant advantagesO Specifica].ly,
the microwave energy has been found to rapidly heat and
vaporize the moisture in the textile material, and
results in a significant shortening of the treatment
time to usually between about 2 to 3 minutes. In addi-
tion, the microwave eneryy effectively drives the
vaporized moisture out o~ the interior of the textile
material and so that the moisture may be readily
removed from the exterior surface of the material by an
airstream of heated ambient air passing thereacross~
Thus there is no need for ventilating air to penetrate
to the interior of the product to carry off the
moisture. This is a significant advantage, since it
minimizes the volume of the ventilating air and it per-
mits many textile products to be treated in folded con-
dition. Thus the products may be initially folded into
consumer sized packages prior to their treatment, and
the treated packages are in a form which may be imme-
diately packaged without further manipulation~ which
could result in an undesirable moisture regain. The
use of microwave energy is also believed to result in a
reduction in energy consumption as compared to conven-
tional heating methods, and it is able to rapidly and
uniformly remove substantially all of the moisture
throughout the interior of the textile material,
without risk of overheating and damage to the textile
material. ~lso, the equipment associated wi-th the use
of microwave energy requires a minimum of space and is
xelatively inexpensive.
Some of the objects and advantages of the
invention having been stated, others will appear as the
description proceeds, when taken in connection with the
accompanying drawings, in which--
Figure 1 is a schematic flow diagramillustrating the various steps of a method representing
one embodiment of the present inventioni
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Figure 2 is a partly schematic perspective
view of a microwave housing adapted for use with the
present invention;
Figure 3 is a sectional end view of the
microwave housing taken substantially alony the Line
3-3 of Figure 2;
Figure 4 is a partly schematic perspective
view of the apparatus ~or inserting the textile pro-
ducts into an opened bag in accordance with the present
invention;
Figure 5 is a side elevation view of a por-
tion of the ap~aratus shown in Figure 4;
Figure 6 is a schematic perspective view of
an apparatus for compressing the textile product and
for heat sealing the open end of the enclosing bag;
Figure 7 is a view similar to Figure 6 and
showing the apparatus in its closed or compressed
condition;
Figure 8 is a sectional view of a ~extile
product adapted to be processed in accordance with the
present invention, namely, a pillow, and taken substan-
tially along the Line 8-8 of Figure 4;
Figure 9 is a sectional view of the product
shown in Figure 8, after having been compressed and
packaged in accordance with the present invention; and
. Figure 10 is a perspective view of the pro-
duct shown in Figure 9.
Referring more specifically to the drawings,
Figure 1 schematically illustrates the basic components
and steps of one embodiment of the present invention.
In this regard, tlle present invention is illustrated as
packaging pillows, but it will be understood that the
present invention is equally applicable for packaging
any of a variety o~ other compressible textile pro-
ducts~ As used herein, the term "compressible textilepr~duct" includes consumer products such as bedspreads,
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quilts, towels, or garments, as well as bulk fiber
packages and non-woven flber webs or materials, and
which may be composed of either natural or synthetic
fibers. In the case of relatively large textile pro-
S ducts, it is preferred that they be folded into a con-
sumer sized configuration prior to treating and
packaging as hereinafter further described.
In accordance with the illustrated embodiment
of the invention, the textile products or pillows 12 to
be packaged are serially advanced through an elongated
housing or tunnel 14 wherei~ they are dried by applying
microwave energy thereto. The tunnel 14 is typically
about 45 feet in lengthO and it includes an endless
perforated conveyor 16 having an upper run 17 extending
horizontally through the tunnel for supporting the pro-
ducts 12 thereon. The tunnel 14 includes an entering
end portion 20 and an exitin~ end portion 21, each of
which have a relatively short height, on the order of
about 4 inches, which are designed to prevent leakage
of microwave power from the tunnel
The tunnel fuither includes a warm air duct
system 22, wherein ambient outside air, which is pre-
ferably initially heated by electric heaters or the
like to about 110-140~4 F., is passed laterally through
the tunnel and across the surface of the products. In
this regard, the air duct system typically has a capa-
city of about 10,000 cfmr and the air enters the side
of the tunnel so as to pass upwardly through the upper
run 17 of the belt and then exhaust laterally from the
tunnel, note Figure 3. The moving heated airstream
acts to carry away the vaporized moisture from the pro-
ducts, and thus serves to speed the drying time, while
also helping to maintain a relatively low temperature
in the interior of the productsO Also~ it will be
noted that with the present invention, the vapor con-
tent of the air is preferably not reduced prior to
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being circulated through the tunnel, and thus the air will contain substanti-
ally all of its ambient moisture vapor. If desired, all of the air may be
recirculated so as to minimize heat loss, although it may be necessary to intro-duce a sufficient amount of outside ambient air to limit the build up of mois-
ture vapor in the circulating air.
A second endless perforated conveyor 24 is posltioned with its lower
run 25 extending through the tunnel and disposed in spaced relation above the
upper run 17 of the lower conveyor, so as to supportingly contact the textile
products 12 during passage through each of the entering end portion 20 and the
exiting end portion 21. Thus the upper conveyor 24 serves to compress any
bulky products to permit them to pass through the narrow entering and exiting
end portions.
The power unit for generating the microwave energy in the tunnel 14
is generally conventional, and may for example comprise the system manuEactured
by Microdry Corporation of San Ramon, California, as Model IV-30-S. The power
unit is typically designed to generate up to 30 KW of microwave power at 915
MHz, a frequency allotted by the FCC to commercial heating equipment. Also,
the design of the entering end portion 20 and exiting end portion 21 for pre-
venting leakage of microwave power is conventional, note for example the U. S.
Patent to Smith, ~o. 3,8587022.
The speed of the conveyors 16 and 24, and the level of microwave
energy, are each determined so that the moisture content of the textile pro-
ducts is preferably reduced to less than about 10% of its normal content, and
most preferably is reduced almost to zero so that the product is essentlally
"bone" dry. In the described apparatus, the products 12 remain in the tunnel
14 for a period of about 2 to 3 minutes in order to accomplish this reduction
in moisture content. Also, the microwave energy acts to raise the temperature
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of the textile material itself only a limited amount, and which is insuEficient
to cause damage to the product. Typically, the temperature of the materlal
will be raised to between about 140 to 150~ F, it being understood that the
amount of the temperature increase will also depend upon the initial moisture
content of the material.
Upon exiting from the microwave tunnel 14, the dried products 12 are
directed immediately to a bagging unit 30 as best seen in Figures 4 and 5. 'rhe
unit includes a feed device having upper and lower cooperating conveyors 32, 33
and an automatic bagging device which includes a stack 36 of suitable plastic
bags 37, an air jet 38 for sequentially opening the top bag as a product is de-
livered, and a cyclically operated lever arm 40 for advancing the product and
enclosing bag to a discharge conveyor 42. If desired, the conveyors 32, 33 may
be positioned so as to compress each product as it enters the associated bag,
so that smaller and thus less costly bags may be employed.
From the bagging unit 30, the products 12 and enclosing bags 37 are
advanced to a compressing and sealing unit 44, wherein a flat plate 46 is
lowered onto each product by a suitable pneumatic piston ram 47 or the like.
The force of the ram acts to substantially compress the product, preferably to
at least 50% of its original volume, and up to about 20-30% of its original
volume in the case of more compressible products such as the illustrated pil-
lows. A partial vacùum may also be drawn in the bag to facilitate the compress-
ing of the product, and to remove the remaining aîr. A heat sealing bar ~ is
mounted on the front edge of the plate 46, and is automatically lowered by the
piston 49 while the product is under compression to heat seal the open end of
the plastic bag, note Figure 7.
As will be apparent, the resulting compressed product 50 is main-
tained in its compressed condition by the bag 37. Also, the material of the
bag is selected so as to have a very low moisture vapor permeability, which
effectively prevents the return of moisture into the interior of the product
for a substantial period of time. As one example, polyethylene sheeting is com-
mercially available in a number of grades having differing moisture vapor trans-
mission rates. Since those materials having the lowest transmi~sion rate are
the more expensive, it is contemplated that the textile products may be initi-
ally individually packaged in a less expensive material of relatively high per-
meability, and then a number of such packages would be repackaged in a material
of very low vapor permeability. It is further contemplated that the resulting
bulk packages could be prepared for shipment by placing one or a plurality of
the bulk packages between top and bottom sheets of corrugated paper, and then
interconnecting the sheets with suitable strapping, to thereby minimize the
amount of outer corrugated paper employed.
When the packages 50 are opened at the retail outlet or by the con-
sumer, the product 12 should be exposed to ambient air for a period of time to
permit it to expand and recover its normal moisture content and original shape
and bulk. While some wrinkles will normally be present immediately upon open-
ing of the package, these wrinkles are not pennanent and they wlll usually dis-
appear upon full moisture regain without the need for pressing or other treat-
ment. In this regard, such recovery ambient air should have a relative humi-
dity of at least about 50 to 60~, and preferably higher, since the higher the
relative humidity, the
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more rapid the full moisture rega.in and recovery of the
original shape and bulk.
In the drawings and specification, there has
been set forth a preferred embodiment of the invention,
and although specific terms are employed, they are used
in a generic and descriptive sense only and not Eor
purposes of limitation.
