US 3458966 A
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Description (OCR text may contain errors)
Aug. 5, 1969 5. cs. DUNBAR ETA!- 6 METHOD OF PACKAGING COMPRESSIBLE MATERIAL Filed March 24, 1966 1g 5 S/DNEY 6. DUNBA/P & MLL/AM 5. HULL/110957 INVENTORS ATTORNEYS United States Patent Oflice Patented Aug. 5, 1969 US. Cl. 5324 3 Claims ABSTRACT OF THE DISCLOSURE Method and apparatus for packaging open cell compressible materials in integrated mat form having backing thereon which interferes with free air flow between layers of mats in which a stack of mats or a coiled up mat is placed in a bag. Air communication is provided from adjacent each of the resulting layers to an opening in the bag. Air is removed from each layer and the enclosure via the air communication passages and the bag opening allowing ambient air pressure exterior of the bag to compress all of the layers and to compress each of the layers evenly. The bag is then restained against expansion.
This invention relates to a method and apparatus for packaging materials in general and, particularly, to a method and means for packaging open cell compressible material. The invention is intended to be applicable to all open cell compressible materials. Although, the present invention is described with reference to compacting and packaging fibrous material, 'both in lengths of integrated mat and in loose mass formation, examples of such fibrous materials being those formed from glass, slag, fusible rock or the like.
It has been conventional practice in packaging or preparing fibrous material, as for example, materials of glass fibers especially usable for insulation purposes, to roll predetermined lengths of fibrous mats in spiral fashion around a mandrel, while mechanically compressing the spiral roll by rollers or other means as the mandrel is rotated, and encircle the finished spiral roll with a sleeve or other holding means to retain the spiral roll in its packaged configuration for shipping and handling. As an alternative, stacks of lengths of fibrous material have been mechanically compressed and inserted into a sleeve or envelope for shipping and handling. Further, fibrous material in loose or mass formation has been packaged by pouring the loose material into a bag, tamping the material, down, adding more material and tamping again, etc., until the bag is full and then closed.
The above methods have been in broad use for quite a while, but attempts to decrease the size of the spiral roll or the height of the flat stacks or to insert more loose maerial into the bags in order to better facilitate handling and to save on shipping costs and storage space have not been too successful heretofore. Difiiculties have been encountered since exteriorly applied compression to the spiral rolled lengths of fibrous material or stacks of flat fibrous material or loose fibrous material results in nonuniform compression of the material and in many instances a portion of the fibrous material may 'be compressed to a degree sufficient to break or fracture the individual fibers thus reducing the resiliency of the material when taken from the package. When such lengths of fibrous material are unpacked for application and use, the fibers, if crushed or broken, will not spring back or revert to their normal expanded condition. The crushing or breaking of the fi-bers substantially reduces the insulating value. rendering the fibrous materials unsatisfactory and inefficient for the purpose intended. Further, when the exterior compressive forces have been applied to a loose spiral roll, the convulsions of the rolled-up fibrous material or mat were unevenly compressed, the backing paper becoming wrinkled or torn and generally exhibiting a tendency to funnel in toward the center, causing objectionable bulges in the fibrous material.
It is, accordingly, an object of this invention to provide an improved means and method for packaging materials.
It is another object of this invention to provide an improved means and method for packaging fibrous material which enables the packaging of more fibrous materials within the same volume occupied by a similar previous package without breaking or mechanically damaging the fibers and thus not reducing the insulating value nor the resiliency of such material so that the fibers will spring back to their normal expanded condition when the fibrous materials are removed from the package.
It is a further object of this invention to provide an improved method and apparatus for packaging open cell compressible materials which provides a finished package in an enclosure protecting the materials from moisture and dirt.
The invention thus features a method for packaging open cell compressible materials which comprises the steps of placing the materials in a substantially fluid impervious flexible enclosure, removing fluid from Within the enclosure through an opening in the enclosure allowing ambient pressure exterior of said enclosure to compress said enclosure and said materials within said enclosure, and restraining the compressed enclosure against expansion. The restraining step may include the step of sealing the opening of said enclosure against admittance of ambient atmosphere to the interior of said enclosure. The restraining step may also comprise placing restraining means around the compressed flexible enclosure and materials to prevent expansion. An example of such restraining means would be a fixed perimeter sleeve.
When the method is applied to open compressible material which has been integrated into a length of fibrous material, the further step may be utilized of rolling the length into a coil before placing the material into the en closure. The coil may be pre-compressed by applying tension to the length as it is being rolled up or by exterior roller means before insertion into the enclosure. When packaging the coil discussed above, the flexible enclosure means advantageously comprises a bag having one open end for removal of the fluid, in which instance the loose open end of the bag maybe inserted into the middle of the coil after the restraining step to provide moisture and dust protection for the material within the package.
The method of this invention as discussed above may also be applied to open cell compressible material which is in loose form. In applying the method to the loose form, the fluid is advantageously filtered as it is removed from the enclosure to insure the retention of the loose material in the enclosure and to prevent the clogging of the fluid removal means. In practicing the method with respect to all types of open cell compressible materials it may be advantageous to provide communication between the opening of the enclosure and a portion of the enclosure remote from the opening to enable removal of fluid from the remote portion. This method may include the step of providing a conduit of open cell compressible material which enables compression of the conduit after the removal of the fluid from the remainder of the enclosure.
The above method may be practiced by apparatus for packaging open cell compressible material, which apparatus is capable of carrying out the steps set forth above. As noted in the method, the apparatus may include conduit means for providing communication between a point of fluid removal and a portion of the enclosure remote from the fluid removal point. In certain instances, the conduit means advantageously comprises a foraminous plenum means adapted to be inserted into the interior of a mass of material to be compressed. The apparatus may further include a flexible enclosure means which has an opening for receiving fluid removing means and sides extending away from the opening. The fluid removing means may include a conduit extending between the sides to the opening. The conduit may have formed therein a plurality of apertures on the sides thereof adapted to draw the sides of the enclosure tightly against the conduit when the fluid is being removed from the enclosure.
The invention may also be practiced with apparatus for packaging open cell compressible material which comprises air barrier means positioned adjacent the sides of the material exposed to ambient pressures, means for removing air from within the cells of such material allowing the ambient pressures pushing against the air barrier means to compress the material, and means for retaining the material in its compressed condition. If the open cell compressible material is in an integrated mat length form having an air barrier backing and is in a rolled up or coiled configuration for packaging, the air barrier means may comprise first and second air barrier members positioned adjacent the sides of the rolled up or coiled configuration.
Other objects, advantages, and features of this invention will be come readily apparent when the following description is taken in conjunction with the accompanying drawings, in which:
FIGURE 1 illustrates the application of the invention to a length of fibrous material in coiled form;
FIGURE 2 illustrates the application of the invention to stacked lengths of fibrous material; and
FIGURE 3 illustrates the application of the invention to open cell compressible material in loose form.
The present invention is described, with reference to compacting and packaging fibrous material, whether in integrated lengths or in loose or mass formation, such fibrous materials being formed from glass, slag, fusible rock or the like. The manufacture of fibrous material has been carried on for several years, and such materials have been used extensively for heating and acoustical insulation in buildings as well as heat insulation on appliances such as refrigerators, freezing units, ranges and water heaters, and in other places where heat loss or heat transfer is to be reduced.
Lengths of fibrous material of this character may be formed by attenuation of fiber-forming material by high velocity gaseous blasts in a manner wherein the fibers are accumulated in haphazard or random assembly into a mass or mat of substantial thickness. The fact that the lengths of the mats of fibrous material are necessarily thick in order to obtain high insulating or sound-attenuating efliciency increases the costs of transportation and storage because of the bulk of the fibrous masses or mat lengths or of loose fibrous material. While the fibrous material is comparatively light in weight, it occupies a comparatively large volume per unit of weight.
As discussed hereinbefore, several methods of packaging have been tried and used with varying degrees of success. The major difliculty in most previous methods of packaging was that in mechanically compressing the mats to a degree where economical transportation was afforded, there was sometimes resultant fiber breakage by the compression methods and apparatus used, which breakage reduced the insulating value and the ability of the fibers to spring back. It has been discovered that fibrous mats may have the air evacuated from within the mass of fibrous materials and greater compression is attained without the breakage of the fibers comprising the mass.
Referring to FIGURE 1, there is illustrated a coil of open cell compressible material which comprises an integrated mass of fibrous materials 11 adhered to a backing 12 to form a length or a mat. The length may be rolled up into the spiral coiled formation 10 on a mandrel in a manner well known in the prior art. The coil 10 may be pre-compressed by applying tension to the length as it is being rolled upon the mandrel, or by applying force exteriorly of the spiral as it is being rolled up by compression rollers pushing against the outside of the spiral.
In one form of the invention a substantially fluid impervious flexible enclosure 15, such as a polyethylene bag, is pulled over the spiral coil 10. The substantially fluid impervious condition of the flexible enclosure may be required to be only substantially air impervious if the fluid medium within which the package is being compressed is atmospheric. If the open cell compressible material has a liquid fluid within the cells or in the interstices between the fibrous material, and if the material is being packaged in a liquid medium rather than a gaseous fluid, then the enclosure should be liquid impervious. The use of the word fluid herein is intended to cover a liquid fluid or a gaseous fluid.
Referring again to FIGURE 1, the flexible enclosure 15 has an opening 16 into which the roll 10 is inserted. Sides 17 of the flexible enclosure 15 extend away from the opening 16. A conduit 21 of a fluid removal means 20 is inserted through opening 16 to withdraw or remove fluid from within enclosure 15 and from the cells or interstices of the fibrous material.
The sides 17 of the enclosure 15 may be adhered in a fluid tight joint to the conduit 21 by rubber band or other constricting means to prevent ambient air or fluid from being admitted to the interior of the enclosure 15. As an alternative, apertures 22 may be formed in the sides of conduit 21 to draw sides 17 closely against conduit 21 to prevent the admittance of ambient air to the interior of the enclosure.
In this embodiment, there is no need for a filter at the end of conduit 21 since the fibrous material is in an integrated mat form and will not clog up the fluid removal means or leave with the fluid being removed. However, conduit 21 may be closed at the end thereof and have perforations 22 also formed in the end closure so that the section of the conduit 21 having the apertures 22 formed therein may be inserted into the middle of the mass being compacted and act as a foraminous plenum for the withdrawal of fluid. Although the conduit 21 is shown in a tubular or cylindrical form, as best suited for use with the spiral roll, it should be noted that a square cross-sectional tubular form may be used or, that in other instances, for example FIGURE 2, a spatulashaped foraminous conduit may be utilized to afford communication with a greater area within the enclosure or within the mass. In the instance of FIGURE 2, a spatula-shaped foraminous conduit may be inserted between layers of the stacked mats.
In the operation of the apparatus of FIGURE 1, fluid is removed from the interior of the flexible enclosure 15 by exhaust or vacuum pump 20 and conduit 21. As the air is removed from within the interior of the enclosure 15 and from within the cells or interstices in the fibrous or open cell material, the ambient atmosphere acts to push against the outside of the flexible enclosure and to compress the enclosure and the material therein. At the end of a fluid removal cycle, the spiral roll 10 is compressed to a suflicient degree so that a fixed perimeter sleeve 25 may be slipped over the outside of the roll 10 to restrain the roll from expansion after the air exhausting or fluid removal means has ceased operating. After the sleeve 25 is in position, the fluid removal means is taken from the opening 16 and the loose ends of the enclosure or bag are inserted into the middle of the roll thereby providing a completely enclosed package which protects the compressed material from dust. If the opening 16 is sealed, the enclosure 15 also protects the roll 10 against moisture.
As an alternative to the use of the sleeve 25, the flexible enclosure may be made of material sufficiently air impermeable over long periods of time so that the compression effect may be retained by simply sealing the opening 16 of the enclosure 15 against admittance of ambient air.
The enclosure 15 may be made from material that is completely impervious to all fluids. However, if a restraining means such as sleeve is used to maintain the compression of the materials, then the enclosure need only be substantially impervious to fluids. That is, the enclosure 15 need only establish a pressure drop against fluid flow therethrough that is sufiicient to allow the fluid removal means 20 to remove fluid from within the enclosure faster than fluid can flow through the surface of the enclosure. Compression is then attained and a restraining means holds the material in its desired compressed state.
Referring to FIGURE 2, there is illustrated a stack of fibrous mats or batts which have been inserted into a substantially fluid impervious enclosure 31. Fluid may be removed from within the enclosure 31 by a fluid removal means 32 similar to that illustrated in FIGURE 1. After compression by an operation as discussed hereinbefore, the stack 30 is suificiently reduced in size so that a sleeve 33 having a fixed perimeter may be slipped over the stack to retain it in a compressed position.
Referring to FIGURE 3, there is illustrated the application of the teachings of this invention to the compression of open cell compressible material in loose form. A mass of the material is inserted into a flexible enclosure 41 having an opening 42. Fluid removal means has a conduit 51 which is inserted into the opening 42. Apertures 52 may be formed in the sides of conduit 51 to draw the sides of the enclosure tightly against the conduit 51 to prevent the admittance of outside air.
In the packaging of loose material, difliculties may be encountered in that the open cell compressible material is not in integrated form and, therefore, would tend to leave the enclosure with the fluid being removed. To prevent this, the fluid is filtered as it is removed from the enclosure. There are a number of alternative ways for accomplishing this. The end of the conduit 51 may be closed and have perforations 52 formed therein so that the conduit itself acts as a filter. However, with certain materials the perforations may tend to become blocked by lodging of particles against and around the openings. In order to avoid this, one may use a screen such as that shown at 53 to filter the fluid and prevent the loose mass from moving toward the conduit 51. Since the enclosure 41 will compress in all directions, the dimensions of the screen 53 should not exceed the smallest dimension after compression of the enclosure 41 so that the enclosure will not be torn or misshapen as it shrinks around the screen 53. To overcome this problem, the screen 53 may be made of a flexible material to compress as the enclosure 41 compresses with and around the material 40.
As a further means for solving this problem, the conduit 51 may be perforated along its length and then the length inserted all the way through to the end of the enclosure 41 to allow the withdrawal of fluid from portions of the enclosure remote from the normal fluid removal point at the opening of the enclosure 42. Thus there is provided communication between a remote portion or portions of the enclosure and the fluid removal point 42. In addition to utilizing the conduit itself as a foraminous extension, a foraminous conduit may be constructed by simply using integrated fibrous material such as a length or a portion of an integrated fibrous mat similar to that shown at 54. The advantage in using the integrated fibrous mat is that it will act as a conduit to allow air to be withdrawn from any portion of the enclosure in which the integrated mat conduit lies, while allowing the integrated mat conduit to be compressed either after the fluid is removed from the loose mass 40 or as the loose mass 40 is being compressed.
A conduit, whether of the foraminous plenum type or of the integrated fibrous material mat type may be used in the instances where a stack, such as shown at 30 in FIGURE 2, has a backing on one side which is substantially air impervious. As the air is exhausted from within the enclosure 31 of FIGURE 2, the enclosure will pull tightly around the stack making it difficult for air to be transferred from one layer to the next so that it may eventually be withdrawn from the enclosure. This may be overcome by providing an upwardly and downwardly extending conduit of integrated fibrous materials in a manner similar to that shown at 54 in FIGURE 3. This then will provide communication with each layer of the stack of mats 31. Similar communication may be provided between spirals in FIGURE 1.
Referring again to FIGURE 3, after the air or fluid is removed from within the enclosure 41 so that the enclosure and the material is compressed to the desired extent, the opening 42 may be sealed to retain the compressed condition of the loose material 40. In packaging loose compressible materials it may be desirable or more practical to construct the enclosure 41 of material sufliciently air impermeable so that no restraining means is needed other than the sealing of the opening 42. If a simple sealing of the opening 42 will not sufiice, then a fixed perimeter sleeve or other restraining means may be used.
Referring to FIGURES 1 and 2 again, fibrous material packaged in this manner quite frequently is provided with a backing which acts as an air barrier. This may be utilized to an advantage. In FIGURE 1, forexample, the backing 12 will resist the intrusion of ambient air into the fibrous mass as air is being exhausted therefrom. Therefore, an air barrier means need only be applied to both sides of the coil 10 while the fluid is being removed therefrom. Although it may be advantageous to provide a conduit or conduits of sticks or mats of integrated fibrous materials such as that illustrated at 54 in FIGURE 3 for the withdrawal of air from within the open cell compressible material 11, it is possible to withdraw the air from the coil 10 since it is in spiral form and the material itself forms one long spiral conduit.
If the vacuum or air exhaust means is strong enough, an air barrier means may be applied to the two sides of the roll 10 and be held in place by the vacuum being formed within the material 11 by the fluid removal means 20. Thus, when the roll is compressed to the proper degree, the sleeve 25 may be slipped over the roll holding it in its compressed condition. Air barrier means, such as polyethylene caps for the sides of the roll, may then be removed and the roll transported to the point of installation. Similarly, with respect to FIGURE 2, air barrier means may be utilized to cover the exposed edges of the stack of mats 30 if the mats have backings. The sides may be individual pieces and not be a complete enclosure as illustrated at 31. The important factor in the utilization of air barrier means rather than a complete enclosure is that the air barrier means must be movable with respect to each other so that the ambient air may compress the material 30 by pushing against the air barrier means.
In tests of the inventive techniques herein, it has been found that a roll 30 inches in diameter may be reduced to a diameter sufliciently small to place the roll in a twenty-one inch sleeve. This allows approximately fifty percent more weight to be packaged in the same space.
In addition to the space having features of the invention, the material is compressed according to the density of the material at a given point. That is, if the stacks or rolls happen to be less dense at one point than another, the less dense points compress more and the package takes the best configuration possible according to the give at various points within the compressible material. This is not possible in mechanical compression. Since the ram or rollers are set to attain a desired uniform dimensional compression, fibers included in particularly dense areas may be crushed or broken, while fibers in an adjacent less dense area are not fully compressed.
In conclusion, it should be noted that the embodiments disclosed and described herein are meant to be illustra tive only and not limiting in any sense. The embodiments serve merely to illustrate the spirit and scope of the invention.
1. A method for packaging open cell compressible materials in integrated mat form having backing thereon which interferes with free air flow between layers of said material comprising the steps of placing a plurality of layers of said material with backing on each layer in a substantially air impervious flexible enclosure, placing a forarninous conduit adjacent the edge of each of said layers to provide air communication from adjacent said edges to an opening in said flexible enclosure, removing air from each layer via said air communication provision and said opening in said flexible enclosure allowing ambient air pressure exterior of said enclosure to compress said enclosure and each of said layers of said materials within said enclosure, and restraining said cornpressed enclosure against expansion.
2. A method as defined in claim 1 in which said material is integrated into a length of fibrous mat and which includes the further step of rolling said mat into a coil to provide said plurality of layers before placing said material into said enclosure.
3. A method as defined in claim 2 in which said flexible enclosure comprises a bag having one open end for removal of air and which further includes the step of inserting the loose open end of said bag into the middle of said coil after said restraining step to retain the material in a completely enclosed protective package.
References Cited UNITED STATES PATENTS 2,863,266 12/1958 Moore 53-22 3,254,467 6/1966 Garrow et al. 53-24 3,307,319 3/1967 Christensen et al. 53-24 X FOREIGN PATENTS 940,552 10/1963 Great Britain.
TRAVIS S. MCGEHEE, Primary Examiner US. Cl. X.R. 53-22