CA1199569A - Method and apparatus for packaging a compressible textile product and the resulting package - Google Patents

Abstract

METHOD AND APPARATUS FOR PACKAGING A
COMPRESSIBLE TEXTILE PRODUCT, AND
THE RESULTING PACKAGE

Abstract of the Disclosure A method and apparatus is provided for the packaging of a compressible textile product (12) under a high degree of compaction to facilitate handling, shipment and storage. Also, the product in the resulting package (50) is essentially "bone" dry, which serves to prevent the formation of destructive per-manent wrinkles, or fiber compression set, in the pro-duct. The moisture is removed in accordance with the present invention by applying microwave energy to the product at an energy level and for a time sufficient to vaporize substantially all of the ambient moisture therein, and the product is thereafter enclosed in a vapor impermeable plastic bag (37). The resulting package is then compressed and sealingly closed, to thereby maintain the compressed condition of the pro-duct and prevent moisture regain in the product.

Description

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 S~,t~

2-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.

5~j~

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 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, 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 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 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 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.

Claims (16)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A method of packaging a compressible textile product so as to reduce its bulk and thereby facilitate subsequent handling, shipment or storage, and characterized by the substantial absence of permanent wrinkles being formed in the product, or fiber compression set, and comprising the steps of removing ambient moisture from the product so as to reduce the mois-ture content to less than about 10% of its normal content and including apply-ing microwave energy to the product to vaporize the moisture therein, then promptly compressing the textile product, and packaging the compressed textile product in an essentially vapor impermeable enclosure and so as to maintain the compressed condition thereof and substantially preclude moisture regain in the textile product.

2. The method as defined in Claim 1 wherein the moisture removing step acts to reduce the moisture content of the textile product to less than about 10% of its normal content.

3. The method as defined in Claim 2 wherein the compressing step acts to reduce the bulk of the product to at least about 50% of its original size.

4. The method as defined in Claim 3 wherein the moisture removing step acts to raise the temperature of the textile product to between about 140-150? F.

5. The method as defined in Claim 3 wherein the moisture removing step further includes passing an airstream across the surface of the textile product to carry away the vaporized moisture from the textile product.

6. The method as defined in Claim 5 wherein the airstream constitutes heated air which contains substantially all of its ambient moisture vapor.

7. A method of continuously packaging compressible textile products so as to reduce the bulk thereof and facilitate subsequent handling, shipment or storage, and characterized by the substantial absence of permanent wrinkles being formed therein, or fiber compression set, and comprising the steps of serially advancing the products through a housing, while applying microwave energy to the products at an energy level suffici-ent to vaporize ambient moisture in each product so as to reduce the moisture content to less than about 10% of its normal content, during its passage through the housing, and while passing an airstream across the advancing textile products in the housing to carry away the vaporized moisture which is released from the products, compressing the products promptly upon leaving the housing, and packaging the compressed products in an essentially vapor impermeable enclosure and so as to maintain the compressed condition thereof and substanti-ally preclude moisture regain in the textile product.

8. The method as defined in Claim 7 wherein the compressing and packag-ing steps include inserting each of the products into an open bag formed of an essenti-ally vapor impermeable flexible plastic sheet material upon leaving the housing, then compressing each of the products to substantially reduce its bulk while it is within the bag, and then sealing the open end of the bag so as to maintain the compressing con-dition of the resulting package.

9. An apparatus for packaging compressible textile products so as to reduce the bulk thereof and facilitate subsequent handling, shipment or storage, and characterized by the substantial absence of permanent wrinkles being formed therein, or fiber compression set, and comprising means for conveying individual textile products in succession along a path of travel, means disposed along said path of travel for applying microwave energy to the textile products so as to vaporize ambient moisture therein so as to reduce the moisture content to less than about 10% of its normal content, and means disposed immediately adjacent the downstream end of said path of travel for serially compressing and sealingly packaging the textile products in a substantially vapor impermeable material, and such that the packaging mate-rial maintains the compressed condition of the products and substantially pre-cludes moisture regain in the textile products.

10. The apparatus as defined in Claim 9 further comprising means for pass-ing an airstream across the textile products while the microwave energy is be-ing applied thereto, and such that the airstream acts to carry away the vapor-ized moisture which is released from the products.

11. The apparatus as defined in Claim 10 wherein said means for applying microwave energy to the textile products comprises an elongate housing, and means disposed within said housing for gener-ating microwave energy, and said conveying means comprises an end-less conveyor having an upper run extending through said housing for supporting the textile products thereon.

12. The apparatus as defined in Claim 11 wherein said housing further comprises an entering end portion and an exiting end por-tion, and means at each of said entering end portion and exiting end portion for suppressing the emission of microwave energy there-from.

13. The apparatus as defined in Claim 12 wherein said convey-ing means further comprises a second endless conveyor having a lower run extending through said housing and disposed in spaced relation above the upper run of said first mentioned endless con-veyor to supportingly contact the textile products during passage through each of said entering end portion and said exiting end portion.

14. The apparatus as defined in Claim 11 wherein said com-pressing and packaging means comprises means for sequentially feed-ing an opened bag to an assembly station, and means for sequential-ly delivering individual products into each opened bag at said assembly station.

15. The apparatus as defined in Claim 14 wherein said com-pressing and packaging means further comprises compactor means positioned adjacent said assembly station for sequentially compact-ing each product and its enclosing bay.

16. The apparatus as defined in Claim 15 wherein said com-pressing and packaging means further comprises heating means for heat sealing the open end of the enclosing bag while each product and its enclosing bag are compacted by said compactor means.