IE46073B1 - Method of treating fibrous materials - Google Patents

Abstract

There is provided an apparatus for wrapping commodities, which may be compressible, and a corresponding method, in which a commodity is conveyed along a fixed path, a pair of opposed lengths of wrapping material are fed in an opposed relationship and in registry, the commodity is inserted between the opposed lengths of the wrapping material which have a leading end which has been sealed to form an open-sided and open-trailing end envelope, the lateral sides of the wrapping material are then sealed, and thereafter, a bag length is severed from the pair of lengths of wrapping material and sealed. Preferably, the commodity is fed under compression in between the opposed lengths of wrapping material, maintained under compression while the wrapping material is side-sealed and is vacuum-packaged while also under compression.

Description

This invention relates to conditioning materials for subsequent vacuum packaging.

In US Patent 3,961,^58, June 8, 1976, entitled PRETREATMENT„ PACKING, STORING AND FINISHING TREATMENT OF TEXTILE MATERIAL PRODUCTS I have taught a method relating to the pretreatment of various textile products. As disclosed, a major problem relating to the conventional attempts to wrap textile products in vacuum packages is that upon removing the product from the vacuum package, it will tend to have semipermanent wrinkles which involves the use of subsequent steps to render the product suitable for consumer sale, particularly in the case of products such as garments. More specifically, it is well known to those skilled in this art that when garments are vacuum packaged, the tendency of the garment to develop semi-permanent wrinkles set into the material of the garment is quite severe due to the wrinkling effect·created by the vacuum packaging steps.

My above US Patent discloses a process to treat garments or the like to reduce or eliminate the tendency of the packaged garment to wrinkle, by exposing the garments to a treating atmosphere for extended periods of time e.g. three to seven days prior to packaging, so as to bring the garments into moisture equilibrium with an atmosphere corresponding to air at a relative humidity Of 0 - 30$ at a temperature of 25°C° For commercial purposes, it may be undesirable to treat garments or the like for up to seven days prior to packaging since this involves a large amount of energy requirements, storage space or conditioning areas, etc. - it would be more advantageous to provide a conditioning process wherein the products to be vacuum packaged are conditioned within a shorter length of time so that, for example, upon their manufacture, they can be subjected to a conditioning step and immediately vacuum packaged without the necessity of utilizing lengthy conditioning time.

In accordance with this invention, there is provided a method of conditioning fibrous material of natural or synthetic nature for vacuum packaging, comprising the steps of treating said fibrous material to reduce the relative regain level of said fibrous material prior to said treatment, reducing the segment mobility level of the fibers of the fibrous material to a level below the segment mobility level of said fibers prior to said treatment and packaging said material while said relative regain level and said segment 2o mobility level of the fibers of the fibrous material are at a level below the respective levels prior to said treatment. 3 07 3 In carrying out the method of the present invention, I various embodiments may be employed to achieve the reduction in the level of segment mobility of the fibrous material and likewise to achieve a reduction in the level of the relative moisture regain of the fibers, as will be described hereinafter in greater detail.

Xn greater detail of the process and apparatus of the present invention, it has been found that the time required for conditioning textile materials, to reduce the susceptiXO bility of the materials to wrinkle upon removal of the same from the vacuum package, can be achieved by controlling the segment mobility of the fibers of the textile material, whether natural or synthetic and as well the relative regain level of said fibers prior to packaging of the same, within a given parametero Segment mobility of fibers, whether natural or synthetic, relates to the fiber molecules which are generally forcefully restrained by entanglement with other molecules, or by actual cross-linking between chains. However, deformation is still possible because of co-operative motions of local segments. The segmental motions in fibers are generally facilitated because amorphous polymers are rather inefficiently placed together In a superfluous space (free volume) present in the form of holes in the order of 10 J? diameter. These segments are set in motion when the fiber mass is supplied with heat and/or moisture and during a process of heating and/or treating any textile material with moisture, whereby the fibers gain moisture through absorption, the segment mobility of the fibers will achieve a given value before attaining a constant and relatively lower value. It is thus possible, in conjunction with the reduction in the level of the relative regain of the fibers, to’ shorten the length of - 4 30 • conditioning time as otherwise proposed where it is desirable b073 to expedite packaging of textile goods such as on an in-line ·.** basis from a manufacturing operation, for vacuum packaging purposes. Thus, with the present invention, by controlling this segment mobility, and the relative regain, during the critical period of conditioning a fibrous material prior to packaging, within given parameters, the textile materials can be rapidly and efficiently conditioned for vacuum packaging without having to wait for lengthy periods of time of e.g. several days. In other words, by controlling the segment mobility of the fibers during a conditioning process, together with the relative regain of the textile materials, the materials may be conditioned to a point suitable for vacuum packaging in a relatively short period of time so that the susceptibility of the textile materials to crease or wrinkle is reduced significantly upon the textile materials being removed from a vacuum packaging. Thus, in accordance with this invention, by controlling the segment mobility of the fibers of the textile materials in conjunction with the lowering of the moisture regain properties of the materials, shortened periods of conditioning may be achieved.

The terra relative regain as used herein defines the amount of moisture regain of a fibrous material at a given relative humidity and is expressed as a value of the moisture regain of the same fibrous material at 90% relative humidity. This may be shown ass % Relative (Moisture) Regain = Moisture Regain at a Given Relative Humidity_ Moisture Regain at 99¾ Relative Humidity . - 5 4 6 0 7 3 In terms of this invention, the relative regain should always be lower than the amount of relative regain of the material prior to the material being conditioned and such relative regain should be brought into a substantially stable level in combination with the substantially stable level of the segment mobility prior to vacuum packaging.

In accordance with a further embodiment of this invention, it has also been found that by lowering the relative regain of a fibrous material within certain parameters, significant improvements in the fibrous material to resist wrinkling can also be achieved and to this end, more specifically, it has been found that if the relative regain level material is lowered by treatment in a gaseous environment below the relative regain level prior to treatment, and specifically to a level below about .32 one can achieve such benefits upon subsequent packaging, particularly vacuum packaging, of the commodity. This is quite unexpected in that heretofore, it has not been considered possible to obtain antI-wrinkling benefits by utilizing a relative regain below’ about .32. In this respect most preferably the relative regain is brought to a level below about .27 and most desirable results have been found by utilizing relative regains below a factor of .22.

As outlined above, relative regain can be determined by the preceding equation; and moisture regain values for most fibrous products are known in the art and reference may be had to such standard information for determining the relative regain values for different materials which are to be employed in the method of the present invention. - 6 4 g jj j g The method of the present invention is applicable to i the treatment of a wide range of fibrous materials, and in particular fibrous materials which are otherwise susceptible to wrinkling under conditions of packaging, storing or the like. The method finds particular application in the treatment of fibrous materials such as textile materials, e.g. clothes (coats, jackets, suits, etc.), sheets, etc. Such articles may be of a compressible nature and the present invention has many advantageous results with respect to compressible fibrous articles - e.g. textile products such a3 pillows, quilts, clothes or garments and with ths method of the present invention, recovery from severe packaging conditions while substantially avoiding wrinkling can be achieved, Xt will be appreciated that there are many other types of commodities to which the present invention is applicable.

The method of the present invention may be carried out using any suitable apparatus achieving or suitable for performing the steps. Thus, suitable enclosure means with air circulation fans may be provided with means being provided for introducing conditioning air. One particular form of such means comprises the apparatus shown in Patent Specification Wo. 46072 in which the conditioning apparatus includes a tunnel witn different treating zones, etc.

In addition, according to the above Patent Specification, there may also be utilized in conjunction with· the method of the present invention the vacuum packaging apparatus for vacuum packaging fibrous materials after treatment. · - 7 40073 The type of packaging material employed for tijr packaging treated products of the present invention may vary widely. Normally, the present invention may advantageously be used for the treatment and packaging of textile materials under vacuum. However, in the event of certain types of products intended to be used shortly after being conditioned by the present method, such products may be. conventionally packaged in suitable packaging material and stored until use with improvements still being obtained in the property of the treated product. This would be applicable to products which are used shortly after manufacture, conditioning and storing.

Xn choosing a vacuum packaging material, and where storage times are contemplated, it is most desirable that such material be chosen so as to have a relatively low moisture vapour transmission rate to reduce moisture ingress into the vacuum packaged product which would otherwise deleteriously affect the producto Various types of plastic laminates may be used for this purpose suitably sealed to prevent air and moisture ingress. Other materials which may also bo used include metallic foil, e.g. aluminum foil, etc. - 8 In general, the segment mobility level of the fibrous material may be lowered in one of several ways typically by treating the fibrous material with a gaseous atmosphere under conditions in which the atmosphere acts on the fibrous material to reduce the segment mobility level. To this end,,the atmosphere may contain relative humidity conditions capable of reducing the segment mobility and/or in combination with temperature conditions may achieve similar results. Likewise, in reducing the relative regain level, the atmosphere may be varied by providing a gaseous environment of a type sufficient to cause the relative regain level to be lowered below a value of about .32.

Particularly preferred treatment conditions of the present invention involve exposing the fibrous material to be treated to a conditioning atmosphere containing a temperature lower than the initial ambient temperature of the fibrous material to be treated, which lower treating temperature may be maintained throughout tlie conditioning of the fibrous material or alternately, which may be decreased incrementally or otherwise throughout the ccnditioning treatment. until such time as tlie segment liability level has been lowered to a desired degree, or until such time as the segment mobility level has been stabilized, and in a like manner, until such time as the relative regain level is lowered to the desired degree or at least belcw .32, preferably ,22 and preferably to a substantially constant level. In this preferred procedure it may be desirable to initially treat the fibrous material using substantially derated temperatures, that is, temperatures in access cf the temperature at which the fibrous material is subsequently subjected to for the purpose of initially reducing the relative regain at a faster - 9 46073 rate and correspondingly while increasing the segment mobility during tills initial phase. Thus, one procedure contemplated by tire present invention involves two or more overall steps in which the initial step is a treatment step to initially subject the fibrous material to lower the relative regain, while increasing the segment mobility and thereafter in one or more subsequent stages of the initial treatment to lower the segment mobility and correspondingly to stabilize the relative regain, followed by a subsequent treatment to stabilize the segment mobility of the fibrous material.

Still further, the fibrous material may be initially treated under substantially constant temperature conditions, but with relatively lav relative humidity conditions to progressively and incrementally decrease segment mobility and relative regain levels of the material, while continuing such treatment until such time as such levels have been decreased below the levels initially involved and preferably, until such time as both have been stabilized.

In sane cases, and for various types of fibrous textile materials, such as underclothes, face cloths, etc., vacuum packaging may be carried on at a point prior to complete stabilization of the segment mobility level of the material where such products need not be totally free of wrinkles for the sake of appearance. In tills case, me may choose packaging conditions in which the product to be packaged has been conditioned to a point prior to segment mobility stabilization - and preferably with relative regain stabilization occurring at that point. However, for most fibrous materials such as suits or other like products, packaging should occur after the relative regain stabilization and segment mobility stabilization have set in - with a packaging operation, such as vacuum packaging, occurring at such levels and while such garments are maintained at such levels.

In particularly preferred embodiments of the present invention, the fibrous materials are subjected to a amditioning atmosphere. - 10 preferably air, at relative humidities ranging fxcn OS to 40% and at temperatures ranging frcm 0°C. to about 42°C., v/ith more preferred conditions involving OS to 401 relative humidity at temperatures ranginn from 0°C. to about 35°C.

Such ranges of temperature and relative hunidity conditions for the treating atmosphere are applicable to a wide variety of products ranging fron textile products which are of a synthetic or natural fiber construction to other products such as paper - e.g. wall papers, writing paper, etc. Particularly preferred tenreratures and humidities for textile products such as clothing, cIoves, etc., involve 0°C. to 35°C., and relative humidities of 20% or less for the conditioning atmosphere. Many textile products may be packaged at even lower relative humidity to expedite the relative regain stabilization or to achieve a relative regain value below .27, at e.g. 15 - 10% or less.

For various products such as textile materials, e.g. suits, coats, etc., two or more stages may be employed - i.e. the materials may be subjected to too or more ocnditioning steps one of which is a treatment step and the other of which is a stabilization step.

Stabilization temperature conditions are preferably relatively lew, . e.g. 25°C. or less and,under relatively low relative hunidity, e.g. % or less, while at the initial treatment stage, the previously described ranges will apply, It will be understood by those skilled in this art that tire 25 temperature and relative humidity osnditions will vary depending cn the nature of the material, the thickness of the fibrous material, the fiber type, etc.

The volume of conditioning air used to treat the garments will likewise vary considerably depending cn the mjJsetp of the fibrous material, etc., as described herein. Normally, however, - 11 4 6 0 7 3 ’ the fibrous material is treated with conditioning air in a volume sufficient to substantially maintain the conditioning air characteristics as close as possible to the ambient conditioning air characteristics at the surface of the fibrous material. Xn this way, the fibrous materials nay be more efficiently treated as opposed to lower volumes vhich ’would cause non-conditioning air characteristics to occur adjacent the fibrous materials.

To this end, the conditioning environment is preferably passed in a moving stream relative to the fibrous materials or alternatively, the fibrous materials are passed in a direction of movement relative to the conditioning environment sufficient to cause the conditioning environment to maintain the conditioning effect adjacent the surface of the fibrous material.

Using the above conditions, the fibrous materials may be treated under normal circumstances to achieve a constant segment mobilization and a -constant relative regain stabilization in a period of 5 hours or less, typically 2 or 3 hours. Textile materials such as coats, etc., may be treated within 1 hour to arrive at stabilized segment mobility and relative regain levels. 2θ Host preferably, in employing treatment conditions in vhich the segment mobility level is lowered by a first treatina atmosphere involving one or more stages, and/or the relative regain is lowered below its initial level, in said one or more stages, and where such treating stage is followed by a stabilization step with one or more stanes, 25 the stabilization step is preferably carried out for a period of time ranging from .1 s 1 to 1 s .1 of the time involved in the treating step, Dssirably, this is within the rance of .5 : 1 to : .5. Under such conditions, the stabilizing atmosphere is preferably at 0 - 20°C. and a relative humidity of 0 - 15%. - 12 46073 + Having thus generally described the invention, reference will now be made to the accompanying drawings, in whichs FIGURE 1 shows a graph of results of experiments carried out at different temperatures and relative humidity for a cotton fabric relating to the removal of moisture under such conditions· FIGURE 2 is a similar graph to that of Figure 1 but showing the removal of moisture relative to a Nylon fabric.

FIGURE 3 is a graph similar to Figure 1 showing sitni— iQ lar results relative to a wool fabric.

FIGURE 4 is a graph illustrating the decrease in moisture regain values relative to a conditioning time factor for the material of Figure 1.

FIGURE 5 is a graph similar to that of Figure k, but relating to the nyloxi material of Figure 2.

FIGURE 6 is a graph similar to that of Figure k but with reference to the wool material of Figure 3· FIGURE 7 is a graph relating to the wrinkling results, relative to conditioning time showing the segment mobility stabilization curves of various materials under certain treatment conditions.

FIGURE 8 is a graph similar to Figure 7 showing similar results but under different treatment conditions.

FIGURE 9 is a graph showing the segment mobility 25 curves for various temperatures and relative regain curves for such temperatures, under given conditioning parameters. - 13 46073 In all of the following tests, temperature measurements are expressed in degrees Centigrade with the standard deviation being plus or minus 2°C.

Referring now to Figures 1 through 3» the graphs 5 illustrate the results of experiments relating to various types of synthetic and natural fibrous materials and more specifically, cotton, nylon and wool materials, respectively. Each of these materials was treated under conditions specified hereinafter by employing samples which were initially tested . for initial moisture regain, and then conditioned under the treatments subscribed hereinafter. Each of these graphs thus illustrates, in summary, that various temperatures will remove varying amounts of moisture from the products and will achieve stabilized moisture content after varying times.

More specifically, with respect to Figure 1^ summarizing results of several tests, the following procedures were employed; Samples of 100$ pure cotton fabric were employed in which the samples were measured to obtain, at the onset of the 2Q tests, 85$ relative humidity which corresponds to an initial regain factor of 9-1/3- Such samples were exposed to a flow of conditioning air at 28°C and 11$ relative humidity and a second group of the same samples at 35 °C and 11$ relative humidity. Conditioning air treatment was carried out for periods up to 120 minutes with intermittent measurements of decrease in the weight percentage of the cotton fabric at various periods of time through the tests. As will be seen from Figure 1, the samples treated at 28°C and 11$ - 14 relative humidity shown by tha curve A became substantially stabilized at about 90 minutes, while the samples treated at 35°C shown by the curve B stabilized somewhat earlier approximately 75 minutes, under the same relative humidity. Increasing temperatures, at the same relative humidity, will thus be seen to decrease the absorbed water of the samples at an earlier point in time.

Similar results are obtained with reference to Figure 2 which illustrates the results of tests using substantially identical conditions to Figure 1, but in this case with pure nylon fabric as having an initial relative humidity of 85%, and an initial regain of 5.5%. In this case, reference letter C designates the curve for material treated at 2S°C and reference letter D material treated at 35°U, with the material being treated at the higher temperature becoming stabilized relative to the decreased amount of moisture at approximately 40 to 45 minutes and that treated at a lower temperature became stabilized slightly above 90 minutes.

In Figure 3» similar tests (using 100% pure wool fabric) under similar conditions were carried out, as illustrated with respect to the results shown in Figure 1. Reference letter E illustrates the results obtained at 28°C under 11% relative humidity and reference letter F the results of similar relative humidity at 35°O. Stabilization for the various samples of both the higher and lower temperatures was in excess of 120 minutes, with the samples having an initial regain of 15·9% corresponding to an initial weight measurement at 85% relative humidity. - 15 4 6 0 7 3 Figure 4 illustrates the summary of tests relating to the factor for achieving moisture regain stabilization with respect to the samples shown in Figure 1. Thus, with Oe initial regain measurements of the materials-used in Figure 1, which was 9.1% the moisture regain values for the materials of Figure 1 over the test ranges show stabilization beginning shortly after 30 minutes of treatment and subsequently stabilizing at 50 to 60 minutes for the measurements of samples indicated by reference letter B under the temperatures and conditions illustrated vzith respect to Figure 1. In a similar vein, the samples shown by the curve A of Figure 4 indicates stabilization beginning at approximately 9θ minutes with the moisture regain measurement of those samples treated vzith a lower temperature.

In figure 5s moisture regain curves for the samples of Figure 2 are shown and again, indicated by reference letters C and D (for nylon) show the moisture regain stabilization under such conditions as were employed in treating the samples of Figure 2, to involve stabilization for the moisture regain values,.for the materials shown by the curve of reference letter C, with stabilization being at approximately 90 minutes and for the curve D at approximately 40 - 4 5 minutes.

Likewise, the stabilization of moisture regain for the material shown in Figure 3o and as illustrated in Figure 6, for the curve E illustrates that a higher temperature treated material will stabilize in excess of 120 minutes, as vzill the material treated at the lower temperature which will· likewise stabilize in excess of 120 minutes, due to the nature of the material and the initial moisture content of the product. - 16 •S 6 ό 7 3 From the above, it will be noted that moisture regain reduction will stabilize for varying materials at varying times, with stabilization being shown by a substantially constant measurement, which in turn, will yield a substantially constant relative regain value in all cases below about ,32 in terms of the equation previously expressed in this case.

Referring now to Figure 7» there is illustrated a graph summarizing the results of tests carried out to determine the propensity of various types of materials to wrinkling, which tests simulate the results of wrinkling as encountered in packaging, particularly vacuum packaging, of various types of commodities made from different types of natural and synthetic materials.

The results of the tests illustrated in Figure 7 were based on test procedures involving samples of the materials indicated. The samples were treated initially in air at 85% relative humidity until moisture regain equilibrium at that humidity was obtained. Each of the samples were then · humidified for different periods of time ranging from 0 to ISO minutes with the samples being in an undefonmed state. Xn Figure 7» conditioning of the samples using atmospheric air was carried out with the atmospheric conditions involving, for the results shown in Figure 7, k0% relative humidity and 35°C with a constant flow rate of atmospheric air at 15 litefsper minute. At intervals of 5» 10, 30, 60, 120 and 180 minutes, the samples were tested by loading the respective samples in a conic wrinkling tester for a period of 10 minutes using a load of 2 kg. Thereafter, the - 17 46073 ' wrinkled samples were permitted to recover in atmospheric air at 65$ relative humidity and 20°Ca with wrinkle height (wrinkle recovery) then being measured using a load of 5 grams after 5-3-5 minute recovery penods.

The results of the above tests for the different time periods are plotted in the form of the curve shown in Figure 7 and illustrate those conditions approximating treatment of the samples to illustrate the wrinkle factor such as would be encountered in vacuum packaging at various levels of segment mobilities of the fibers of the fibrous materials involved. Thus, from Figure 7, the state of, or level of, segment mobility of the different materials will be evident.

The materials involved in the tests shown by the curve of Figure 7 included 100$ nylon, the results of which are shown by the curve of reference letter G§ 100$ cotton the results of which are shown by the curve of reference letter H, a blend of nylon and polyester fibers the results of which are shown by the curve indicated by reference letter I, pure wool the results of which are shown by the curve designated by reference letter J, a mixture of wool and polyester fibers the results of. which are shown by the curve designated by reference letter K and finally 100$ polyester the results of which are shown by the curve defined by reference letter L.

* Figure 7 also illustrates, on the horizontal axis, the results of extended periods of testing showing the point at which the segment mobility levels in the different materials have been stabilized.

As will be seen from the results shown on Figure 7, segment mobility stabilization indicated by an absence of wrinkling under the test conditions can be achieved in a relatively short period of time. However, under the conditions specified using conditioning air at 35°C with 4o% relative humidity, segment mobility stabilization for materials such as cotton, cotton mixtures and nylon were longer.

By varying the treatment conditions, according to a further set of experiments, segment mobility stabilization can be achieved at a greater rate. To this end, the results shown in Figure 8 are the results of tests carried out on substantially identical samples to those used with respect to the experiments of Figure 7 but in this case, the conditioning atmosphere involved treatment using 15 liters of conditioning atmosphere per minute having a relative humidity of 10% and again at 35°C starting with the samples having an initial relative humidity in equilibrium with air at 85% relative humidity and 20°C.

Similar letter designations, shown by the correspond25 ing letters G', H’, etc., in Figure 8 indicate similar materials to those of Figure 7 and in this eas - 19 4 6 0 7 3 polyester, wool-polyester and nylon became substantially stabilized in relatively short periods of time indicating that the segment mobility had become stable at which time the products of these materials could be vacuum packaged without semi-permanent wrinkling being set into the matenal.

The results of numerous other similar tests, similar to those shown in Figure 7 and 8 have illustrated that for varying conditioning atmospheres, segment mobility stabilization can be achieved but that until such time as segment mobility stabilization is achieved, products packaged (as summarized by the conic testing methods) would have semi-permanent deformations therein which of course is totally undesirable» From such tests, segment mobility stabilization for the materials of Figures 7 and 8 can be seen to form stabilized conditions by varying tbe treating temperature and in general, earlier segment mobility stabilization can be achieved by initially utilizing condition ing temperatures which initially lower the relative regain values of the samples to a substantially stabilized level whereafter the conditioning atmosphere utilizing lower temperatures to provide stabilized segment mobility will result in combined stabilized relative regain levels and stabilized segment mobility levels» This is Illustrated in greater detail in Figure 9 which clearly shows the combined results of relative regain and segment mobility factors relative to the propensity to wrinkle. In Figure 9, curve W illustrates the use of initial conditioning temperatures at 35°c on samples of fibrous material, curve X the use of conditioning air at 30°C on samples of the same material and curve Y the results of the use of conditioning atmosphere at 25°C and in which the 6 0 7 3 initial samples being treated by the conditioning air contain 65$ relative humidity at 20°C. Correspondingly, the relative regain curves illustrate, under similar conditions to those described above, the relative regain for the temperature curves V, X and Y, but in this case, the respective relative regain curves are designed by W’, X' and Y'> With respect to the samples having the above initial conditions (65$ relative humidity), o those treated with conditioning atmosphere having a 35 c temperature measurement and a nominal relative humidity (curve W) show an increased segment mobility in the fibrous material after initially being treated by the conditioning atmosphere and a subsequent decrease until a substantially stabilized segment mobility is obtained which is at a level iS below the segment mobility level of the material prior to treatment. Correspondingly, the relative regain, curve W* shows an initial significant decrease, as shown by the earlier figures and thereafter achieves a substantially stabilized condition in advance of the segment mobility stabilization.

At the point where the relative regain and the segment mobility levels of the fibrous matedal are substantially constant, the fibrous material may be packaged by e,g. vacuum packaging without suffering any deleterious effects.

Similar results are shown by the curves X and X* which at lower conditioning temperatures and similar nominal relative humidity values, indicated a lower rise in segment mobility with a shorter period of time before segment mobility stabilization was achieved, but conversely, slightly longer times were required for relative regain stabilization. 6 0 7 3 In this latter case, however, relative regain stabilization was still achieved prior to segment mobility stabilization, and again both the relative regain and segment mobility stabilization levels using the conditioning atmosphere were at a point below the original level of the materials being treated.

Curves Y and Y' show similar results and at lower temperatures, but lower initial segment mobility increases are encountered but with greater relative regain times involved prior to stabilization for relative regain.

In all of the above cases, once stabilization of segment mobility had been achieved and with relative regain stabilization, conditioning was carried on using conditioning air under substantially constant conditions e.g. 20°C and 10$ relative humidity, to maintain stabilization. At this point, garments or the like of such materials can be safely vacuum packaged without detrimental wrinkling being permanently or semi-permanently set in the material.

With reference to the above examples conical wrinkling is known in the art and reference may be had to Wrinkle Recovery Properties of Cotton Fabrics at Changing Moisture and Temperature Conditions, SIRTEC, Symposium International de la Recherche Textile Cotonniere, Paris, April 22 - 25, 1969 for the procedures involved. - 22 4 S Ο 7 3 The following example illustrates one embodiment of the method of the present invention, in which the method utilized different conditioning air environments.

This example was carried out using the apparatus 5 of the above-mentioned Patent Specification, ana in the treatment zone of such apparatus, conditbning air was provided ranging from 30°C to 20°C and containing 30 - 15% relative humidity while in the stabilization zone, conditioning air was introduced ranging from 20°C - I5°C and 12 - 5% relative humidity.

Numerous tests have been carried out under such conditions using various types of fibrous materials - e.g. textile products in the form of garments, pillows, and the like.

In one such test, men's suits of 100% wool were introduced into the apparatus, with the ambient atmospheric conditions being at that point approximately 30°C and 60% relative humidity. The garments were initially treated with conditioning air using such air at the rate of kOO liters/20 second.. In the stabilization zone, conditioning air was introduced at the rate of 200 liters/second. Air temperatures in the initial portion of the treatment zone were approximately 30°C decreasing to approximately 20 - 15°C and with the air In the stabilization zone being maintained at a constant - 20°C.

The garments were treated in the treatment zone until such time as the segment mobility of tho wool material was substantially stabilized and likewise the relative regain come to a substantially stable level. Thereafter, the garments - 23 4 6 0 7 3 ,. were maintained in such stabilized condition for approximately V minutes with a total conditioning time being approximately minutes.

In the method, after continuous running, condxtxon5 ing air was introduced using a mixture of ambient air and treated air so that the mixture obtained was one in which the relative humidity varied from approximately 3θ% at the initial stage of the treatment zone to approximately 15% at the end of the treating zona while in the stabilization zone the relative humidity was maintained at a constant 10%.

The apparatus employed according to the above-mentioned Patent Specification -had tha following -characteristics; the length of the treatment zone was approximately 10 meters with the height of the whole system being approximately 2 meters and having a width of approximately 80 centimeters. The stabilization zone had a length of approximately 10 meters and air was removed at a constant volume of approximately 480 liters per second (with a total of 1200 cubic meters per hour being removed from both zones).

Upon exiting from the stabilization zone, the garments were tested and found to contain a relative regain of below .22. - . Β I) ί 3 The garments were subsequently wrapped and vacuum packaged using the apparatus described in the abcvementioned Patent Specification. The volume cf such garments was reduced under vacuum packaging to l/3 to 1/2.

They were thereafter stored for one week and the vacuum packaging removed. The garments were tested to determine the wrinkle characteristics and such garments were found to be substantially free from wrinkles by employing the method of this invention.

If desired, following removal of the vacuum packaging and in order to expedite recovery of the garments from this compressed state to their normal original condition, the product may be re-conditioned by exposing the same to relative humidities of 5θ% or greater and temperature conditions of 25. P 45°C. However these relative humidities and temperature conditions will vary depending on the type of product, the nature of the fibrous materials, etc.

Claims (24)

1. A method of conditioning fibrous material of natural or synthetic nature for vacuum packaging, comprising the steps of treating said fibrous material to reduce the 5 relative regain level of said fibrous material prior to said treatment, reducing the segment mobility level of the fibers of the fibrous material to a level below the segment mobility level of said fibers prior to said treatment and packaging said material while said relative 10 regain level and said segment mobility level of the fibers of the fibrous material are at a level below the respective levels prior to said treatment.

2. A method as defined in claim 1, wherein said 15 treating of said fibrous material is carried out by providing a fibrous material with a first segment mobility and a first relative regain level, and exposing said fibrous material to a gaseous environment to a lower said segment mobility level and said relative regain level to a second level below 20 said first level and continuing the exposure of said fibrous material to said gaseous environment until the segment mobility level and the relative regain level is substantially constant.

3. A method as defined in claim 1, wherein said fibrous 25 material is treated by exposing said fibrous material to a gaseous environment having a temperature sufficient to reduce the segment mobility level of the fibers of the fibrous material to said level below the level prior to said treatment and to reduce said relative regain level to a level 30 below said level prior to said treatment.

4. A method as defined in claim 1, wherein said fibrous material is treated by exposing said material to a gaseous environment for a sufficient period of time to lower said segment mobility and said relative regain to said levels 35 . below the levels prior to treatment and wherein the level of said relative regain is below 27. -264 6 0 7 3

5. A methcd as defined in Claim 1, wherein the step c£ lowering ¥ the relative regain and the segment nobility comprises exposing said article to a dehunidifying atmosphere of predetermined tenperature wherein the segment inability level of the fibers of said article is reduced to a preselected level 5 less tlian tha segment mobility level of said .fibers at a temperature exceeding said predetermined temperature and thereafter, vseuttn packaging said article with tire segment mobility level of said fibers during packaging being at a level no greater than said preselected level. 30

6. A method as defined in Claim 1, wherein the fibrous material is •treated by successively exposing said article to first and second atmospheres, the terperature of said first atmosphere exceeding tiie terperature of said second atmosphere and the relative humidities of said first and second atmospheres being selected to .15 provide a decrease in the relative humidity of said article throughout the course of such conditioning, and vacuum packaging said article while said article has temperature and relative humidity established by said conditioning. 20

7. « h method as defined in claim 1, 2 or 3, wherein said fibrous material is treated by exposing said fibrous material to conditioning air having substantially the sane relative humidity as said fibrous material, said conditioning air having a temperature Ισ-.’er titan the temperature of said fibrous material prior to treatment with said 25 conditioning air. -3Π 4 6 0 7 3 •ο * · ο

8. Λ method as defined in dlaim 1, wherein said fibrous material is treated by conditioning said material in at least tvzo different atmospheres and in which at least one subsequent atresphere to the first of said two atmospheres has a relative humidity lower than 5 that of the preceding atmosphere, said fibrous material being exposed to said atmospheres for a period of time sufficient to lower the relative regain of the fibrous material to a level below about .27.

9. · a method as defined in claim 1, wherein the fibrous material is a 10. Fibrous product, and the product is treated to reduce the relative regain level to a value of not mere than 27.

10. A method as defined in claim. 9, wherein the relative regain is reduced to a substantially constant level, and wherein said product is treated to reduce the segment mobility level of said fibrous 15 material to a level below that prior to said product being treated and until the segment nobility level has reached a substantially constant level.

11. A method as defined in claim 2, 3 or 4, wherein said gaseous environment is atmospheric air, said air being conditioned to lower said segment mobility level and said relative regain level. 20

12. A mathod as defined in claim 9, wherein the relative regain level of Said fibrous material is reduced by exposing said fibrous material to a gaseous environment having a substantially constant temperature, but with a relative humidity sufficient to lower said relative regain level of said fibrous material to a point where said relative 1 > * 4 6 072 regain level raintains a substantially constant level.

13. A method as defined in claim 1, 2 or 3, wlierein said fibrous material is treated by exposing said material to atmospheric air in an initial treatment zcne and subsequently in a stabilising zone, said 5 fibrous material being treated in said treatment zcne until said segnant mobility level of said material maintains a substantially constant level and until said relative regain level maintains a substantially constant level, and thereafter maintaining said substantially constant segment nebility level and said relative regain level for a period jj of time ranging iron .1:1 to 1:.1 of tne time .said material was initially treated.

14. A method as defined in claim 13, wherein said fibrous material is initially treated at a temperature of O°C. to 50°C,, P5 and said fibrous material is subsequently treated at a tee^erature of 0 - 40°C ;

15. A method as defined in claim 13 or 14, in which the atmosphere has a relative humidity of froni 1¾ to 30%. 20

16. A method as defined in claim 1, wherein said fibrous material is treated by exposing said material to atmospheric air to reduce the segment mobility level lower than the segment mobility level of said material prior to treatment, and to reduce the relative regain to a level below ,27, aid subsequently packaging said material when said 25 segment mobility and said relative regain levels are at cr below such levels. -IV

17. Λ method as defined in claim 1, 2 or 3, of conditioning textile materials of natural or synthetic origin, for vacuum-packaging, which reduces the tendency of such materials to wrinkle or crease upon release of the materials frern the vacuum-packaging, by the steps of 5 exposing the fibrous material to a gaseous environment containing air at a temperature sufficient to reduce the senment mobility of the fibers of the fibrous materials to a level below the segment mobility level of the said fibrous materials prior to being exposed to said gaseous environment, said conditioning being carried out for a time period of up 10 to 240 minutes, and stabilizing said treated materials by maintaining said segment mcbilitv of said materials at a level below the level of the segment mobility of said first step under gaseous conditions of less than • 20% relative humidity and'-st a ’temperature of less than 38°C., said stabilization step being carried out for a period of time of between 15 .1 : 1 to 1 :.J- of the tine factor that the material have been subjected to in said conditioning step, and subsequently packaging said material.

18. A method as defined in claim 5, 9, 16 cr 17, wherein said 2o material is packaged under vacuum conditions in a flexible wrapping material having a lew moisture vapor transmission rate.

19. A method as defined in claim 1, 2, 3 or 9, wherein said material being treated is a textile material. 25 20. A method as defined in claim 17, wherein said stabilizing treatment is carried out for a tine ratio of from .5 : 1 to 1 s .5 relative to the time the textile material has been treated in the conditioning step, said material being treated for up to a total of 4 hours. 21, Λ rcthod aa defined in claim 17 or 20, wherein said material is treated in said treatment zone for a period ranging from ’β’Ί' 2 minutes to 2 hours and in said ccr.diticning zone for a period of from 2 minutes to 2 hours. 5 22. A method as defined in claim 1, 2 or 3, wherein said segrent mobility of said fibrous material is lowered from an initial level to a preselected level by exposing said material to a gaseous environment having a temperature lower than the temperature of said material prior to said treatment, 10 23. A method as defined in claim 1, 2 or 3, wherein said segment mobility of said fibrous material is lowered fron an initial level to a preselected level by exposing said material to a gaseous environment having a relative humidity lower than that of the material prior to treatment. 15 24. A method as defined in claim 1, 2 or 3, wherein said segment mobility of said fibrous materials'is Icwerdd fron an initial level to a preselected level by exposing said material to a gaseous environment having a tsiroerature lower than tire terroerature of said material prior to said treatment, and a relative humidity lower

20. Than that of the material prior to treatment.

21. 25. A method as defined in claim 9, wherein the treatment step initially increases the segment inability level of the material to a level above the level prior to treatment, and subsequently decreasing said segment mobility level to below the level prior to said treatment, 25 said treatment reducing the relative regain to a substantially constant level prior to said packaging step.

22. 26. A methcd as defined in claim 1, 2 or 3, wherein said fibrous material is initially exposed to an atmosphere at an elevated tanperature, said atmosphere having a relative tumidity lower than the relative humidity of the fibrous material, and thereafter treating by exposing 5 said fibrous material to an atmosphere at a temperature lower than the temperature of said elevated tanperature, ard having a relative humidity lower than the relative humidity of the material prior to said treatment, said material being exposed to said last-mentioned atmosphere for a period of time sufficient to provide a substantially stable relative 10 regain level and to provide a substantially stable segment mobility level, and thereafter said material is packaged at or below said substantially stable levels of relative regain and segment mobility cf the material.

23. 27. A method as defined in claim 1, or 2 or 3, wherein the relative 15 regain is reduced to a level below .32.

24. 28. An improved methcd cf conditioning and vaccum packaging fibrous material of natural or synthetic nature in which the material is treated under certain moisture and temperature conditions whereupon the filrous material is vacuum packaged to thereby reduce the tendency of the 20 fibrous material to wrinkle when it is under vacuum packaged conditions characterized by the following steps: removing moisture from the fibrous material by drying the same while the fibrous material is in an atmosphere having a tanperature above zero degrees C and a relative humidity of 0-48 percent during 25 a time period of up to 5 hours to reduce the relative regain of the fibrous material to a level below .32, lowering the tenperature level cf the fibers of the fihrcus material to thereby lower the segnent mobility level lower than the segment mobility level of the fibrous material prior to removing the moisture and thereafter when the 3q relative regain and segment mobility of the fibrous material is substantially constant vacuum packing said fibrous material while said relative regain level is below .32 and said segment mobility level of the fibrous material is lower than the segment mobility level of the fibrous material prior to said treatment.