US 3028281 A
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Description (OCR text may contain errors)
April 3, 1962 T. J. KARASS PACKING TAPE Filed Dec. 22, 1959 Unite rates This invention relates to means for banding, strapping and bundling boxes, cartons, bales and the like, and to unitizing, and more particularly to an improved strapping material per se as well as an improved means for bolding the overlaying ends thereof together.
A common method of securing and reinforcing bales, boxes and the like is the use of a steel band tightly encircling the article and having the ends thereof secured together by means of a clip or clasp which is deformed inwardly against the edges of the strap and which also deforms the edges of the strap to provide inter-engaging portions which prevent the strap from slipping out of the clip. When used for binding cardboard or paper wrapped cartons the steel bands have a strong tendency to cut into the edges of the packages and when used for banding furniture or the like for shipment, expensive wooden forms must be provided to prevent the metal strap from cutting into the finished surface thereof. There are numerous other disadvantages connected with the use of steel strapping; for example, the only practical way of removing the steel strapping is by cutting through the strap itself and this requires the use of tin snips or the like which may not be available, particularly when the strapped package is delivered to the home rather than to a business establishment which regularly receives such shipments. Another disadvantage of the steel strapping is that since it is normally under tension the ends snap apart when the band is cut and since these ends have sharp corners are apt to injure the person opening the package. The steel band is also difficult to dispose of after it has been removed and has sharp edges which often cut the hands. When the package or bundle bound with steel strapping is of a material which expands under conditions of moisture or the like, the steel band will either break upon expansion of the package or will cut into the package, since the strap is incapable of stretching to any appreciable extent.
It is an object of the present invention to provide a strapping material and securing means therefor which has a tensile strength approaching that of the heretofore used steel strapping so that for many operations it may be used as a substitute for steel strapping and yet which overcomes all of the disadvantages of steel strapping as mentioned above.
It is a further object of the invention to provide a strapping material which is considerably more flexible and considerably less expensive than steel strapping but which has a tensile strength approaching that of steel strapping.
It is a more specific object of the invention to. provide a banding device comprising a flat band of textile material the ends of which are held together in overlapping relationship by means of a metal clip.
A further object of the invention is to provide an improved weftless tape of high tenacity suitable for use in banding and reinforcing shipping cartons, boxes and the like.
A still further object of the invention is to provide an improved metal clip for securing the overlapped ends of a flat weftless tape of textile material.
Other and further objects, features and advantages of the invention will become apparent as the description of certain preferred embodiments thereof proceeds.
-' atent ice Referring now to the drawing:
FIGURE 1 is a perspective view of a shipping carton bound with the binding device of the present invention;
FIGURE 2 is a plan view showing the overlapped ends of the improved weftless tape secured together in accordance with the invention;
FIGURE 3 is a sectional view taken along the line IIIIII of FIGURE 2;
FIGURE 4 is a plan View showing a slightly modified form of the invention;
FIGURE 5 is a perspective view of the improved clip or clasp as it appears before being applied to the strap; and
FIGURE 6 is an illustration of one of the yarns used in making the tape.
In the drawing, a carton 10 formed of cardboard or corrugated paperboard is shown bound with straps 11 each of which is pulled tight about the carton and has overlapping ends which are secured together by means of a metal clip 12. The band 11 is one of the important elements of the invention and is in the form of a weftless tape comprising a plurality of strands of textile material secured or adhered together in side-by-side arrangement to form a tape one yarn thick and several yarns Wide. The individual strands are high tenacity tire cord type yarns and as illustrated in FIGURE 6 an individual yarn 13 comprises two strands 14 and 15. The strands 14 and 15 are each formed of a large multiplicity of continuous textile filaments which are twisted together and the two strands are then twisted or plied together in the opposite direction to form the yarn 13. As a specific example the yarn 13 may be 1650 denier high tenacity regenerated cellulose or viscose rayon, 2 ply, 5 8 turns per inch in singles and 5 2 turns per inch in doubles. In more common language this means that the strands 14 and 15 are twisted 5 turns per inch in a clockwise direction and the two of them are then twisted together with 5 turns per inch in the counter-clockwise direction.
In forming the tape a number of yarns 13 are brought together in side-by-side relationship and thus led through an aqueous bath containing an adhesive. After removal from the bath the yarns, now adhered together to form a tape, are dried under tension or in some instances the tape may be stretched while still wet and dried while being maintained in the stretched condition. It is generally understood that regenerated cellulose or rayon yarn as originally manufactured has a rather high degree of elongation and that this elongation can be reduced to almost any extent desired by a slashing operation wherein the yarn is wetted and dried under tension with or without stretching. It has been previously mentioned that one of the disadvantages of steel band strapping is that it will not stretch and it will be appreciated that the tape of this invention can be made to have various degrees of stretchability or elongation. Thus if the strap is to be used, for example, in baling hay, it will be made to have a relatively high degree of extensibility so that when the bale gets wet and expands the strap will not cut into and through the hay and, on the other hand, when used for strapping articles not subject to expansion the band will be treated to reduce the extensibility of the yarn to a minimum.
When the yarns are regenerated cellulose the adhesive may be essentially an aqueous solution of polyvinyl alcohol but preferably it will comprise an emulsion containing polyvinyl acetate, a filler such as clay and a plasticizer, for example, dibutyl phthalate. The adhesive emulsion may include partially hydrolyzed polyvinyl acetate or blends of polyvinyl acetate and polyvinyl alcohol. In order to provide a desired degree of stiffness for the tape the adhesive pick-up should be between 15 and 30%, that is, the total weight of the tape should include from about 15% to about 30% adhesive bath material.
While the yarn 13 in the specific example mentioned above is described as 2 ply 1650 denier, in practice it will often be desirable to use a 3 ply tire cord type yarn. As used in the present application the term tire cord type yarn is to be understood to mean a twisted strand comprising of two or more other strands each of which contains a multiplicity of continuous filaments and wherein the individual strands are each twisted in the direction opposite to the twist of the complete strand of yarn. Instead of being formed of rayon the yarn may be nylon, polyethylene, polypropylene, and acrylic fiber such as Acrilan or other synthetic linear polymer. These latter materials are all thermoplastic in nature and when the tape is formed of such material it is not necessary to employ an adhesive inasmuch as the yarns may be autogenously bonded to one another by means of heat. When using this method of adhering the yarns together the amount of heat employed should be just enough to cause the yarns to bond to one another and not enough to destroy the fibrous or filamentary character of the yarns. Whether employing an adhesive or bonding by means of heat-sealing, it is only necessary that the bond be sufficiently strong to hold the strands together during normal handling before the tape is applied to the package.
The type of clip or clasp and the manner of crimping the same employed with steel band strapping are not satisfactory for securing the ends of the tape of the present invention and therefore another feature of this invention is a new clip and a new manner of cooperation between the clip and the weftless fabric tape. One form of clip which has been found to be satisfactory is shown in FIGURE 5 and consists of a piece of sheet metal bent into the form of a sleeve or flat tube. The overlapping portions of the sheet metal are secured together by spotwelding as'indicated'at 16 or a continuous line of welding may be provided. The metal forming the clip is corrugated as indicated at 17 transversely of the overlapping portions thereof to provide rigidity for the clip and permit the use of relatively light gauge metal.
The two ends of the tape are threaded through the sleeve 12 and the tape is drawn taut about the package, after which the sleeve is crimped entirely across the width thereof so that each of the yarns forming the tape is correspondingly crimped as best shown in FIGURE 3 wherein a pair of transverse crimps are indicated at 18 and 19.
The crimps are in the form of smooth flowing curves having a radius of curvature greater than the diameter of the yarn strands. The crimps thus provide a snubbing action which restrains the ends of the tape from slipping upon one another and from slipping out of the clip but it is important that the crimps do not sharply bend the yarn strands because a sharp bend will cause a very considerable weakening of the yarn whereby under tension it will always break first at the sharply bent point. In addition to the transverse crimps the clip is also deformed inwardly against the side edges of the tape as shown at 20 in order to'provide a more secure grip of the tape.
Although undue bending or deformation of the yarn strands is to be avoided, it has been found that the holding quality of the clip may be improved without seriously weakening the strap by providing depressions or inwardly directed dimples 21 within the transverse crimps 18 and 19. As shown in FIGURE 4 the dimples within the crimp 19 are out of alignment with the dimples in the crimp 18. That is to say, the dimples in the crimp 19 cooperate with and deform different ones of the individual yarns of the tape than do the dimples within the crimp 18. This arrangement assures good gripping of many of the individual strands without causing interference between deformed portions of adjacent yarn strands.
The binding device of the present invention may be readily removed by cutting the strap with ordinary scissors or with a pocket knife and this is a considerable advantage over steel strapping particularly in those cases where the package is delivered to the home. The edges of the tape are rounded and it will not cut the hands. Also, disposal of the binding device is no problem inasmuch as everything except the small metal clip may be readily burned. This invention is especially valuable for the shipment of furniture inasmuch as it is not necessary to provide a wooden frame around the furniture to prevent the strap from cutting into the finished surface as is necessary with steel band strapping. Numerous other uses and advantages of the invention will readily suggest themselves to those accustomed to the use of steel band strapping.
Having thus described the invention, what is claimed is:
1. A flat weftless tape comprising a plurality of high tenacity regenerated cellulose tire cords, said cords being arranged in side-by-side touching relation in a single layer, and an adhesive composition holding said cords to one another, said adhesive composition comprising a vinyl resin and a plasticizer.
2. The tape set forth in claim 1 wherein the vinyl resin is. polyvinyl acetate.
3. The tape set forth in claim 1 wherein the adhesive composition constitutes from 15 to 30% of the weight of the tape.
4. A flat weftless tape comprising a plurality of high tenacity twisted cords of continuous regenerated cellulose filaments, said cords being arranged in side-by-side touching relation in a single layer and an adhesive composition holding said cords to one another, said adhesive composition comprising a vinyl resin and a plasticizer.
5. The tape set forth in claim 4 wherein the adhesive composition constitutes from 15 to 30% of the weight of the tape.
References Cited in the file of this patent UNITED STATES PATENTS Runton June 30, 1959