US2713001A

US2713001A - Packaging

Info

Publication number: US2713001A
Authority: US
Inventors: Fred W Manning
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-03-08
Filing date: 1954-03-08
Publication date: 1955-07-12
Anticipated expiration: 1972-07-12

Description

July 12 1955 Y F. w. MANNING PACKAGING Filed March 8, 1954 IN V EN TOR.

PACKAGING Fred W. Manning, Palo Alto, Calif. Application March 8, 1954, serial N0. 414,717

28 Clflml. (Cl. 99171) My invention relates to improved methods and apparatus for the packaging of various articles, such as machinery, furniture, fruits, vegetables, meats etc., and particularly relates to the spinning of enclosures about animal carcasses at the time'and place such enclosures are required. This application is a continuation-inpart of my copending application, Serial No. 185,240, filed September 16, 1950, subsequently issued as Patent No. 2,687,363, which in turn is a continuation-inpart of my application, Serial No. 742,247, filed April 18, 1947. now abandoned in favor of the present invention.

Prior practice was to avoid evaporation of moisture and resulting shrinkage of a carcass by wrapping the carcass of a freshly killed animal in a factory-made muslin or other cloth, and then chilling the carcass for a given length of time before removal of the shroud. But factory-made cloths are expensive, are not moisture and vapor proof, and a close wrapping was difficult to accomplish. Dehydration resulted in freezer burn," and there will always be freezer burning", where air pockets exist. And, of course, oxidation ultimately produced rancidity.

To avoid some of the above objections, particularly the air pockets, various methods were tried: Small animals, such as poultry, were dipped in melted wax; or the carcasses were introduced into thin flexible bags and air removed therefrom by pumps; or the bags were shrunk about the carcasses by immersion of both in hot water; or the bags were filled with water and the latter then drained through restricted outlets and the bags sealed upon completion of the drainage. The first method required time for heating the wax and much machinery, particularly if the carcasses were large; and thin flexible bags had not sufiicient tear strength for large carcasses.

Smooth surface solid filaments of substantial and uniform length and strength cannot ordinarily be produced from fibre-forming materials and stretch-oriented by force of a fluid stream alone. Therefore, manufactu red goods, such as guns, were surrounded with a web of unoriented filaments of irregular lengths and no strength. To obtain an enclosure of sufficient strength the web was heavily coated with a plastic impregnant solution containing large amounts of expensive, explosive and nonrecoverable solvents.

As distinguished from such prior practice, it is an object of my invention to provide a method and means whereby a fibre-forming material is attached in predetermined relation to predetermined amounts of discrete pulling solids, the material disrupted and attenuated into discontinuous fibres which adhere to the solids, and the solids propelled by an elastic or liquid fluid stream, or other impulsive force, so as to exert a greater stretching force on, or molecular orientation of, the fibres than can be exerted by such forces without the aid of the solids. In this way fibres are produced of substantial length and strength, and both length and United States Patent r Y 2,113,001 Ice Patented July 12, 19.55

strength are substantially uniform. The propulsion force, if a fluid, may then be used to aid in depositing the stretch-oriented fibres either in a plastic and adhesive condition, or in a set and adhesive condition,

or the fibres may be made adhesive after deposition to cause them to adhere at their intersections to form an integral fabric.

It is also an object of my invention to spin an enclosure from filaments of substantial and uniform length and strength about a carcass of an animal at the time and place required, and to produce an enclosure that is moisture-vapor-proof, also air-tight when necessary,

and thus avoid the harmful effects of dehydration,'

oxidation and introduction of bacteria.

A further object is to provide an enclosure of regulated porosity that will permit considerable air transmission while restricting loss of moisture from the enclosure. This prevents too high a concentration of carbon dioxide when packaging fruits and vegetables. It also permits contact of the oxygen of the air with the cut surface of meat, apparently necessary to insure the best color and keeping quality of the product.

Another object is to provide a fabric enclosure which will absorb a certain amount of moisture, as for instance 25 to per cent of the dry weight of the fabric, so as to prevent blood discolorization of meat from freshly slaughtered animals.

A further object is to produce a flexible, stretchable, lightweight enclosure, the fabric of which can be colddrawn into the pockets of a carcass so that the enclosure clings permanently and closely thereto. In similar manner, the enclosure can be made to adhere close ly to the irregular surfaces of other articles to be enclosed.

A still further object is to use a molten spray to bond the intersecting filaments of an enclosure to one another and form a film coating over the interstices of the enclosure, and to make such coating absolutely greaseproof and which will not fracture at subzero temperatures.

Another object is to bond discontinuous filaments at their maximum spinning (individual stretching) tension in a continuous circuit to form an integral enclosure.

' so that there need not be any loss of stretch-orientation during later operations.

In accordance with one aspect of my invention, if the article to be enclosed is a freshly killed and eviscerated animal, the carcass is preferably enclosed before the animal heat has dissipated and there is any evaporation of moisture. Thermoplastic filaments are attached in predetermined relationto absorbent pulling fibres and conveyed by force of a iluid stream which cooperates with a reciprocating movement of the spin,- ning gun during rotation of the carcass. This results in the filaments being stretched tightly around and over all parts of the carcass to be enclosed.

The spinning is continued until the mesh of the filamentous enclosure has become suiliciently fine to retain a coating of high melting point wax, or other suitable material, sprayed thereover without destruction of the absorbency of the pulling fibres. This closes the in terstices of the enclosure whereupon the air and moisture is exhausted therefrom, and particularly from the pockets of the carcass. The enclosed carcass can then be dipped in cold brine, hosed down with a refrigerant, or stored in a refrigerator, preferably at a temperature between 33 F. and 36 F.

The enclosure can be slit and peeled off as if it were the skin of the animal. It can be stripped from a frozen carcass, or it can be removed after partial or complete thawing. However, when desirable, a powder, such as before theenclosure is spun thereover.

The breathability of the fabric for certain foodstuffs can be regulated-by continuing the coating until the vacuum pump withdraws only a very limitedamount of air per minute through the enclosure after the fabric has been cold-drawn into the pockets of the article being enclosed.

' The fibre-forming materials used for the production of the fibres or filaments of my enclosures may be organic or inorganic, and thermoplastic or thermosetting, such as the usual plastics extruded into filaments, films, and foils. Some of the most common of these are: polymeric amides, vinylidene chloride, polyethylene, polystyrene, glass, etc., spun from a molten state; cellulose-acetate, polyvinyl-chloride-acetate resins, etc., spun from an acetone solution; protein-base materials, petroleum derivatives, etc. in droplets or otherwise used for coating and impregnation purposes, and there 'are many materials,- such as enamels, paints, etc., which can be used for such purposes but canot be spun into fibres.

Some of the pulling solids which can be used for stretch-orienting fibres and may be incorporated and bonded thereafter by them into integral fabrics are: protein fibres, such as shredded scrap leather; mineral solids,

such as asbestos, vermiculite, perlite, etc'.; vegetable fibres,

such}: cotton, wood, yucca, sisal, etc.; adsorbtive solids, such as carbon, silica gel, etc.; and stretch-oriented fibres having a higher softening point than the fibres to be stretch-oriented.

Other types of pulling solids and which can be sepa-" forming material; plastic solids, such as polyvinyl alcohol pellets, which may be washed from the fabric by a water solvent; frangible solids, such as starch, glucose, diatomaceous earth, which may be reduced to powder by impact or explosion and the powder removed by an air blast or suction; polytetrafluoroethylene pellets, which become non-adherent on' quenching; sodium alginate and other natural or man-made fibres which can be removed from a finished fabric by means of an alkali or other solvent wash.

All such solids can be used for pulling and attenuating fibre-forming materials into stretchoriented fibres; all such solids can be propelled from a rotor in a constant stream to produce a succession of fibres of two to twentv feet in length under a fluid pressure of to 150 pounds per square inch. However, the fibers may be even shorter than indicated above and still have substantial length, such as are produced when the outer end of a comparatively short length enclosurefor directing the propulsion of the solids is positioned close to the fibre depositing surface, or the solids are propelled by centrifugal action and disintegrated on contact with the wall of the said enclosure. And, of course, the substantial strength of the fibres results from theirrnolecular stretch-orientation resulting from the pull of the said solids, as indicated above.

The fibre-forming material may be charged onto the periphery of a primary rotor in discrete solid or fluid-portions uniformly spaced to contact discrete pulling solids similarly spaced on, or uniformly distributed over, a secondary rotor; the material may be charged onto the periphery of a primary rotor either as a fluid or solid film coating to contact discrete solids, uniformly spaced on or distributed over a secondary rotor; or the functions of the two rotors may becombined in one rotor by depositing the said material and pulling solids in succession, one above the other.

To obtain and maintain adhesion between a heat reactive fibre-forming material and pulling solids until the fibres have reached their maximum stretch, the material may be heated to a fibre-forming fluidity and an adhesive All such materials can also be sprayed condition prior or subsequent to deposition on a primary rotor; the solids may be heated sufiiciently prior or subse-v quent to deposition on a secondary rotorto cause the said material to acquire fibre-forming fluidity and become adhesive on contact; or the material and solids may be deposited in succession and in contact on one rotor and the material acquire fibre-forming fluidity prior or subsequent to the said contact. If the fibres become set or nonadherent during attenuation, they will usually be coated with an adhesive spray, introduced through an ejector, so that upon deposition they will become bonded to one another.

A gaseous atmosphere within the spinning chamber may be used to accomplish various purposes. A blast of cold air may set and cold-draw the filaments; steam may be used to maintain the filaments in an adhesive condition until deposited; nitrogen may be used instead of air to prevent oxidation; and the pressure maintained by fluid streams within the chamber may be such that a frangible pulling solid will explode and separate itself from a filament immediately upon discharge. from .the chamber. All such fluid streams may be introduced adjacent to or through the wall on which the pulling solids have been deposited, or by means'of an ejector on the outlet of the stretching chamber. Therefore, by "gaseous atmosphere within the spinning chamber, I mean an atmosphere therein that is different from normal in temperature, pressure, or composition.

The invention is exemplified in the following description, and a preferred arrangement is illustrated by way of example in the accompanying drawings in which:

Fig. 1 is an elevation view showing an enclosure being spun about the carcass of an animal.

Fig. 2 is a cross section of a side of beef showing a fabric enclosure to be cold-drawn to adhere closely to all sides of the cut.

Fig. 3 is a vertical section of a gun for spinning purposes.

Fig. 4 is a vertical section of a modified form of spinning gun, in which the functions of the two rotors shown in Fig. 3 are combined in one rotor.

Referring to the drawings more specifically by reference characters:

Fig. 1 shows a carcass 85, such as a side of beef, supported by a top turntable 86 to which it is hooked, and a bottom turntable 87 into which its neck is thrust. The turntables rotate in synchronized relation, and are driven by a motor 88 through:

bevel gears

89 and 90; drive shaft 91 which carries top and bottom drive pulleys 92 and 93, respectively; top and bottom drive belts 94 and 95, respectively, and top and bottom driven

pulleys

96 and 97, respectively. The top driven pulley and turntable are keyed to opposite ends of the shaft 98 which turns in a bearing 99, and the bottom driven pulley and turntable are keyed to opposite ends of the shaft 100 which turns in a bearing 101.

The motor also drives a suction pump llllwhich is connected to the lower turntable bya pipe 103.,and the whole apparatus is supported by the steel structure 104 movable on the rollers 105. The carcass revolves rapidly as the spinning gun S moves on a reversible thread on the drive shaft between the upper and

lower stops

106 and 107, respectively. The gun reverses its direction of 1 movement each time it strikes a'stop, both of which are fabric to be pulled therein and to adhereclosely toall sides of the carcass. The sealing of the top of the enclosure is accomplished by spinning the fabric tightly around the shank of the carcass up to the point at which the supporting hook 109 is inserted; and the bottom sealing is accomplished by extending the enclosure onto the cylindrical portion of the turntable so that as the neck of the carcass is withdrawn theenclosing sock may be heatsealed orftiedwithout change in the air pressure dif ferential. I '1 Discrete fibres for pulling the filaments enter the spinning gun through a flexible hose connection 110; an agent, such as steam, oil, or water may enter the ejector 111 through the flexible'hose connection 112 and contact the stretched filaments for quenching or other treating purposes; and a second flexible hose connection 113 and ejector 114 may be used to treat the quenched filaments with a drying agent, such as heated air. Hand wheel 115 is used for adjusting the height of the top supporting arm of the steel structure to the length of the carcass. The freezing of the carcass may be accomplished prior to, simultaneously with, or subsequently to, the formation of the enclosure.

Fig. 2 shows a section of the side of beef indicated in Fig. 1. The enclosure follows the line 116 until the filaments are cold-drawn by removal of the air pocket under an air pressure differential. The fabric line 116 then becomes line 117, and the enclosure closely adheres to all sides of the carcass.

Fig. 3 shows the details of the spinning gun S indicated in Fig. 1. Fibre-forming material is introduced into the hopper 118 in the form of discrete solid portions 119. These are fed through a rotary regulating valve 120 into uniformly spaced pockets or reservoirs 121 in the periphery of a top or primary rotor 122. This rotor turns about a stationary annular axis 123 into which a heating medium, such as steam, enters from inlet 124 for the purpose of bringing the reservoir contents to a fibre-forming fluidity by the time they contact discrete solids 125 carried by the secondary rotor 126. The said contact is accomplished by movement of the peripheries of the rotors through converging arcuate paths, and attenuation of the fibre-forming material into filaments 127 results from the movement of the peripheries through diverging arcuate paths.

The fibres may be supplied by an apparatus, such as shown in Fig. 4 of my U. S. Patent No. 2,152,901, or Fig. 3 of my U. S. Patent No. 2,336,745, and are held in position on a suitable section of the drum by passage of the fibre conveying fluid therethrough. This is arranged by the four stationary arms, 128, 129, 130, and 131, forming the three

suction chambers

132, 133 and 134,

arms

129 and 130 having openings 135 therethrough so that all three chambers are connected to a suction outlet 136; and to aid the suction in maintaining the fibres in position, roll 137 calenders the fibres immediately upon deposition. Arms 128 and 131 form a pressure chamber 138 which is connected to a fluid pressure inlet 139 so that when the filaments reach their greatest positive attenuation the fibres are blasted from the periphery of the rotor. This attenuates filaments 127 into filaments 140, whereupon the inner ends of the filaments are severed by jet flame 141.

The rotors are enclosed in a steel casing 142 which ex tends on the discharge side of the rotors into a spinning barrel 143 through which the fibres and filaments are propelled.

Rolls

137 and 144 support and drive the lower rotor from a source of power not shown, and the rotor is in rolling contact with and drives the upper rotor about its annular axis which is held in a fixed position between the side walls of the casing.

Fig. 4 shows a device in which the functions of the two rotors described above are combined in one rotor. In this arrangement the pulling pellets 150 are introduced into hopper 151, fed by a rotary valve 152 at a regulated speed through an opening 153 in the casing ,154 into 6 pockets 155 of the liner 156, which encloses and travels with the rotor 157. The liner pockets are connected by radial openings 158 with pockets 159 in the rotor, and radial passages 160 connect the latter pockets during the movement of the rotor successively with: a suction port 161 to a suction chamber 162, having a connection 163 to a source of suction; and a pressure port 164 to a pressure chamber 165, having a connection 166 to a source sufiicient in size to accommodate one pellet.

of fluid pressure. Suction will hold the pulling pellets in position without the aid of the casing until after the former have received a coating of, or the pockets have been completely filled with, a fibre-forming fluid material from the extrusion screw 167. Thereafter, the adhesiveness of the said material to the pockets will hold the pellets in position until propelled therefrom. The extrusion screw is enclosed within a cylindrical chamber 168 which is attached to one side of the rotor casing, and to the opposite side of the casing is attached a spinning barrel 169 through which the pulling pellets are propelled to produce filaments 170.

Example I For packaging purposes, such as spinning an enclosure about a beef carcass at the time and place required, a polyamide fibre-forming material having a molecular weight of about 10,000 is used in conjunction with cotton fibres, as indicated in Figs. 1 to 3.

The polyamide 119 is introduced into the hopper 118 in the form of solid pellets of about .06 inch in diameter and fed as required by the rotary valve into uniformly spaced pockets 121 of the rotor 122, each pocket being Steam at 300 F. entering through connection 124 into the stationary axial chamber 123 heats the rotor sufliciently to reduce to pellets of fibre-forming fluidity at about 275 F. without carbonizing or otherwise injuring the cotton fibres described below.

Discrete cotton fibres are deposited on that section of the foraminous periphery of the lower rotor 126 between the

arms

128 and 129 by a current of air from a blower not shown, the air passing through the surface of the drum, opening in the arm 129, and out of suction connection 136. The two rotors have nearly the same diameter, about 24 inches, and both travel at .a peripheral speed of about sixty feet per minute. The

converging paths of the peripheries of the two rotors bring the fluid pellets into adhesive contact with the discrete fibres, and the diverging paths of the peripheries positively attenuate the pellets into filaments 127. During this contacting and stretching periods, the adhesive nature of the fluid polyamide causes the pellets to adhere to their reservoirs, and suction from connection 136 holds the fibres in position, openings 135 in

arms

129 and 130 making this possible.

When the deposited fib res reach a position opposite the pressure chamber 138, they are subjected to a blast of air heated to about 300 F. from the fluid pressure connection 139 which gives them a theoretical initial velocity of 20,000 feet per minute. This attenuates the comparatively short length filaments 127 into filaments of substantial length, and constitutes their secondary stretching. The pockets at this point are supposed to be exhaustedof their fibre-forming material but if an excess still remains in the pockets the filaments can be severed therefrom by 55 a flame from the heating jet 141.

To package an article, such as a beef carcass, the upper arm of the steel structure 104 is positioned by handwheel 115 so that the neck of the side of beef 85 can be inserted in the lower turntable 87 and the hook 109 of the upper turntable 86 thrust through the shank. The turntables are driven in synchronized relation by means of motor 88,

bevel gears

89 and 90, and the common drive shaft 91. Upper pulley 92 on the drive shaft is connected to the upper turntable through the belt 94, and the pulley 96 on the turntable shaft 98; and the lower-pulley 93 on the drive shaft is connected to the lower turntable through belt 95, and pulley 97 on the turntable shaft 100. A I rotative speed for the side of beef of 60 R. P. M. is thus obtained.

The spinning gun. S described above moves on a reversible thread on the drive shaft, reversing its direction of movement each time the gun strikes the upper and

lower stops

106 and 107, respectively, and moves the length of the carcass about once per minute. If the rotation movement of the carcass and the up-and-down movement of the spinning gun are sufficiently rapid, the filaments will be stretched and deposited in a tensioned condition. And, of course, a succession of fibres propelled from the rotors results in a substantially uniform overlapping of the ends of the filaments as they are deposited over the carcass.

The spinning gun is supplied with polyamide pellets from hopper 118, and short cotton fibres from pipe connection 11.. Saturated steam at pounds pressure enters ejector 111 through pipe connection 112 for quenching purposes, and heated-air enters ejector 114 from pipe connection 113 for drying the quenched filaments.

As soon as the mesh of the fabric has been reduced sufliciently to retain droplets, a spray gun is substituted on the reversible shaft for the spinning gun and the fabric is coated with wax. The wax is preferably amorphous and sprayed at a temperature between 140 F. and 165' F. When this coating makes the fabric substantially impervious topassage of air, cock 108 is opened to permit the suction pump 102, also driven by the motor, to exhaust air under a vacuum of inches mercury through pipe line 103 from the inside cavities of the beef. This colddraws the filaments so that the fabric hugs all portions of the beef, as shown by line 117 in Fig. 2.

The filaments are deposited partly cold-drawn after passing through the quenching ejector, and the final colddrawing is accomplished by means of a differential pressure exerted on the fabric enclosure by the suction pump. The spraying, however, may be regulated or interrupted during the cold-drawing so that minute openings will remain or occur throughout the fabric enclosure, and the size of these may be regulated to permit considerable air transmission and at the same time restrict loss of moisture from the enclosure. In other words, the porosity of the fabric can be regulated by the amount of spray used, and the amount of the latter required can be determined by the volume of air drawn through the enclosure by the pump. Under normal conditions this will seldom exceed one cubic foot of free air per minute from a six cubic foot enclosure when the pump is operating at a vacuum of 20 inches mercury. V 4

In this way a strong, flexible, extensible, heat-sealing. moistureproof enclosure can be produced; and it may be oxygenproof, or it may have regulated air-permeability.

Moreover, it is greaseproof; it will not fracture at sub-- zero temperatures; and the cotton pulling fibres, when necessary, will take up from to 50 per cent of their weight in moisture.

Vinylidene chloride at a temperature between 240 F. and 280' F.; polyethylene at a temperature between 200' F. and 220' F.; and polystryrene at a temperature around 200- F., may all be substituted for the molten polyamide .of the above example, particularly for the packaging of smaller articles where enclosures of as great strength are not required. For most purposes, the filaments produced from such fibre-forming materials will be deposited in an adhesive condition, and preferably bonded to one another by their own adhesiveness. However, if they are cold-drawn, or quenched by the propulsion fluid or other fluid from an ejector, they can be coated by an adhesive spray, such as wax, pectin, etc. from a second ejector and thereby bonded to one'another upon deposition.

Example II Packaging fruit for shipment can be accomplished by s cient strength to retain the --fruit in position carcass 85 of Fig. l, filling the container with fruit, and spinning a filamentous enclosure thereover, as described 'in Example I.

Instead of using wax, polyethylene at a temperature of 220 F. is sprayed in droplets over. the enclosure during the cold-drawing of the filaments until the pump 102 draws only a small amount of free air per minute,

, enclosure is spun thereover, as described above.

as in Example I. Stopping the coating at this point will leave the enclosure suficiently gas permeable to prevent too high a concentration of carbon dioxide. However, the required breathability depends on the kind and ripeness of the fruit and the'temperature at which it is to be stored; and the amount of free air pumped through the enclosure will not only depend'on this breathability but also on the size of the enclosure.

Or a smooth cylindrical metal container equipped with an arcuate orconical handle and coated on the outside with an anti-adhesive, such as polytetrafluoroethylene, can be used temporarily for enclosing the fruit or other articles in bag enclosures. The container and contents are supported by the turntables, and a fabric After the enclosure around the container has been completed, both are removed from between the turntables, turned up-sidc-down, and the container easily withdrawn from the bag. The open-top bag can then be tied or sealed for shipping purposes.

Example 111 To make what is known as a package house" a wire framework outline is first constructed. This may be of comparatively great mesh in which the wires are spaced from 6 to 36 inches apart. The rollers of the spinning gun supporting structure, shown in Fig. 1, move on a track encompassing the framework, and are propelled by a source of power not shown. This encircling movement of the spinning gun may follow an irregular course to take care of the contours of the house, and is carried out simultaneously with the reciprocating upand-down movement of the gun.

The enclosure is spun from a molten fibre-forming polyamide, the filaments being cold-drawn about the wire framework with the aid of vermiculite, perlite or asbestes pulling solids. The solids and filaments are then bonded together by a spray coating of asphalt heated to 230' F. However, for a certain type of house, I prefer to use a coating of polyethylene which has incorporated therein aluminum powder for heat reflecting and decorative purposes, and is sprayed over the polyamide enclosure at a temperature of 220 F. Such a house will be light. in weight and can be completely sealed against the hoards of insects found in tropical countries. If the house is to be a permanent structure, the wire mesh is welded to a number of steel uprights with footings suitably embedded in the earth.

In another type of house, a balloon is roped substantially to the desired contours to 'give shape to the fabric enclosure. The wire framework can be eliminated and the filament enclosure bonded firmly to the steel uprights. However, before using a balloon for shaping purposes, it must be coated with a suitable antiadhesive so that when the fabric enclosure is complete the balloon can be readily stripped therefrom.

Obviously, a house can be built from a glass fabric enclosure by the above method. Glass filaments can be spun by means of a high temperatured blast from a spinning gun of heat resistant material, and the filaments can be stretch-oriented by the aid of asbestos, perlite or micaceous pulling solids, and both filaments and solids bonded to and about a wire framework. The filaments are set at the moment they are deposited but both solids and filaments can be coated during conveyance with either a thermoplastic or a polyester resin substituting a porous cardboard container of just sufli- I. which will bond them upon deposition. If a thermofor the setting resin is used, the coating can beset by heat from a blow torch.

Example IV A shipping package for an article of machinery can be accomplished by using a copolymer of a polyvinylchloride-acetate resin of 7500 to 15,000 molecular weight in an acetone solvent as a substitute for the polyamide of the former examples, and rotating the machinery while a strong filamentous structure is spun thereover. Or if the machinery cannot be conveniently rotated, the spinning gun can accomplish the enclosure by combining encircling and reciprocating movements. as indicated in Example III. I

To make the enclosure impervious to air the pulling fibres, bonded by vinyl-chloride-acetate filaments, are then coated by spraying a vinyl paint film of .001 to .01 inch in thickness-thereover, the solvent vapors being carried off by pump 88 to a condenser. In similar manner, filaments can be spun from a cellulose acetate resin in an acetone solvent. However, when the articles to be packaged are affected by the solvent, it is usually desirable to spin the enclosures without the aid of a solvent from suitable materials brought to fibre-forming fluidity by heat. 1

While several specific examples have been given, it is obvious that a great many fibre-forming materials may be used for packaging purposes, both in the construction of a filamentous enclosure and for coating purposes, and that an enclosure may be completed before, during, or after freezing or chilling of any foodstufi.

The same materials can be used for coating an enclosure as for spinning the filamentous structure of the enclosure by increasing the molten temperature slightly above the spinning temperature. mean a loss of molecular orientation for the filaments. Since the strength of the enclosure should exist mainly in the filaments. a preferred method is to use material for spray coating purposes whose molten fluid temperature is below the softening point of the filaments.

it is also obvious that a fluid fibre-forming polymer can be charged, into the reservoirs of a conveying wall in discrete portions, or as a film coating of the wall, by an extrusion screw. In the latter case, there must be sufficient clearance for the film coating between the wall and the housing. If the said polymer is charged onto the wall in a solid condition it must be brought to fibreforming fluidity by heat adjacent to or from within the wall, or by heat from the contacting pulling solids. Likewise, the pulling solids may be charged onto.

or into the reservoirs of, a wall in a spaced or uniformly distributed condition and, when desirable, heated prior to or during conveyance on the wall. And the conveying walls for the said polymer and solids may be adjacent, or they may be the same for both.

I claim as my invention:

1. An integral nonwoven fabric comprising a plurality of discontinuous filaments extending beyond one another in substantially uniform overlaps and bonded to one another.

2. The fabric of claim 1 in which the said overlaps are in predetermined spaced relation.

3. The fabric of claim 1 in which the said overlaps'are in substantially straight lines and of considerable length.

4. The fabric of claim 1 in which the said filaments are taut and in substantially parallel relation to one another.

. 5. The fabric of claim 1 in which the said filaments are bonded to one another by a thermoplastic coating whose melting point, is below the softening point of the filaments.

6. The fabric of the claim l'in which the said filaments are thermoplastic and selected from the group consisting of polymeric amides, vinylidene chloride, polyethylene, polystyrene, copolymers of vinyl chloride-acetate resins, and glass.

This, however, may 4 tin ' to form an endless fabric,

7. An integral nonwoven fabric comprising discontinuous filaments of substantial length and discrete'solids, the said solids being bonded into the said fabric in predetermined relation to and by the said filaments.

8. The fabric of claim 7 in which the said solids are cellular and the said filaments are solid.

9. The fabric of claim 7 in which the said solids are short fibres arranged haphazardly, and the said filaments are positioned in substantially uniform alignment.

10. An endless enclosure comprising superposed series of discontinuous filaments in which the filaments of each series are positioned in overlapping and spaced relation throughout a continuous circuit, and are bonded in intersecting condition to the filaments of a succeeding series 11. The enclosure of claim 10 in which the said filaments of each of the series extend beyond, and are spaced from, one another substantially uniformly.

12. The enclosure of claim 10 in which the said filaments are substantially in alignment, and are adherently connected at predetermined points to discrete fibres in nonalignment.

13. The enclosure of claim 12 in which the said filaments are solid, the said fibres are cellular, and including a thermoplastic coating for the said enclosure the melting point of which .is below the softening point of the said filaments.

14. The enclosure of a claim 13 for an article having pockets therein in which the said fabric is distorted at predetermined points to fit'into the said pockets and exclude air from the said enclosure.

15. The method of forming an enclosure about a filament supporting structure, which includes the steps: propelling stretch-oriented discontinuous filaments substantially endwise by force of a fluid stream; depositing the said filaments to intersect one another and in continuous circuits about the said structure by relative reciprocating and rotative movements of the said stream and structure, and bonding the said filaments at their said intersections to form an integral enclosure for the said structure.

16. The method of claim 15, including the step" of.

said solids with a portion of the said adherent material by force of a fluid stream to attenuate the material into discontinuous filaments attached to the solids, and convey the filaments and solids; moving the said stream and said article relatively and in predetermined relation during the said conveyance to distribute and deposit the said filaments and said solids in a continuous circuit over the article; and bonding the said solids by the said filaments to form an integral'enclosure for the said article.

19. The method of claim 18 in which the said solids are absorbent and the said filaments of the said enclosure intersect and form interstices therearnong, and including the step of coating the said enclosure with an agent to close the said interstices and make the exterior of the said enclosure impervious to the passage of air and moisture without destroying the absorbency of the said solids for moisture within the enclosure.

20. The method of claim 19 in which the said article said article to form a cold-drawable enclosure having interstices therein; coating the said interstices with an 7 agent to make the said enclosure relatively impervious to the passage of air and moisture; subjecting the saidenclosure to a diiferential fluid pressure to cold-draw the said enclosure within and about all portions of the said article and to remove air therefrom; and sealing the said air exhausted enclosure hermetically.

22. The method of claim 21 in which the said filaments are conveyed by a fluid stream and deposited over the said article by relative reciprocating and rotative movements of the stream and article.

23. The method of claim 22 in which the said article is a freshly killed, skinned and eviscerated animal, and all the said operations areaccomplished before dissipation of the animal heat thereof, and including the step of chilling of the said carcass before removal of the said enclosure.

24. The method of claim 22 in which the said agent permits a regulated breathability of the said enclosure without escape of moisture therefrom.

25. In an apparatus for producing a nonwoven fabric enclosure about an article, the combination of a member whose peripheral surface is adapted to move through an endless circuit; primary and secondary feeding means for supplying discrete solids and fibre-forming material, respectively. in adhesive contact with each other to the said surface; means to propel the said solids away from the said surface and attenuate the said material into discontinuous fibres during movement of the surface through the said circuit; and means for moving the said article and the said propulsion force'relatively to deposit the said 12 fibres so that the ends thereof extend beyond one another in substantially uniform overlaps to form a complete enclosure for the said article.

26. The apparatus of claim 25 in which the said pro- I pulsion force is a fluid stream, and the said means for moving the said article and propulsion force relatively is so constructed and arranged that the said stream and article are given simultaneously relative reciprocating and rotative movements. 7 4

27. The apparatus of claim-26 in which the said stream is given the said reciprocating movement, and the said article the said rotative movement.

28. The apparatus of claim 26 in which the said article has pockets therein, the filaments ofthe said enclosure have interstices thereamong, and including: means for coating the said enclosure to make the said interstices impervious to the passage of air and moisture; means for exhausting air from the pockets of the said enclosure; and means for sealing the said enclosure hermetically.

References Cited in the file of this patent UNITED STATES PATENTS 2,336,745 Manning Dec. 14, 1943 2,357,392 Francis Sept. 5, 1944 2,433,000 Manning Dec. 23, 1947 2,437,263 Manning Mar. 9, 1948 2,473,528 Hoover June 21, 1949 2,527,628 Francis Oct. 31, 1950 2,569,169 Heritage Sept. 25, 1951 2,584,693 Gerard Feb. 5, 1952

Claims

18. THE METHOD OF PACKING AN ARTICLE COMPRISING UNITING A FIBRE-FORMING MATERIAL AT PREDETERMINED AND ADHERENT POINTS OF CONTACT A DISCRETE SOLIDS; PROPELLING THE SAID SOLIDS WITH A PORTION OF THE SAID ADHERENT MATERIAL BY FORCE OF A FLUID STREAM TO ATTENUATE THE MATERIAL INTO DISCONTINUOUS FILAMENTS ATTACHED TO THE SOLIDS, AND CONVEY THE FILAMENTS AND SOLIDS; MOVING THE SAID STREAM AND SAID ARTICLE RELATIVELY AND IN PREDETERMINED RELATION DURING THE SAID CONVEYANCE TO DISTRIBUTE AND DEPOSIT THE SAID FILAMENTS AND SAID SOLIDS IN A CONTINUOUS CIRCUIT OVER THE ARTICLE; AND BONDING THE SAID SOLIDS BY THE SAID FILAMENTS TO FORM AN INTEGRAL ENCLOSURE FOR THE SAID ARTICLE.