US3045303A - Plastic lined seals for strapping - Google Patents

Description

July 24, 1962 w. WADE 3,045,303.

PLASTIC LINED SEALS FOR STRAPPING Filed Deo. 22, 1959 Fig- 9 3,045,303 PLASTIC LINED SEALS FR STRAPPING Worth Wade, Rosemont, Pa., assigner to American Viscose Corporation, Philadelphia, Pa., a corporation of Delaware Filed Dec. 22, 1959, Ser. No. 861,251 2 Claims. (Cl. 24--18) This invention relates to seals for securing the overlapping ends of tapes or straps and more particularly to seals for Weftless tapes formed of a plurality of side-byside strands.

It is contemplated that the seals of this invention will find greatest utility in sealing the ends of cord tape, a weftless tape for-med of high tenacity tire cord type yarn which has recently been introduced as a substitute for and improvement upon steel strapping heretofore used extensively for binding shipping cartons, boxes and the like. However, it will be appreciated that the invention is also useful in connection with other types of tapes and straps` and it is not the intention to limit the invention to the use in connection with tape formed of any particular type of cord or strand.

It is a ygeneral object of this invention to provide means for sealing the end of cord tapes without bruising, ruptur- `ing or breaking the tape.

It is a further object of this invention to provide means for sealing the ends of cord tapes Without the use of complicated and expensive tools.

It is another object of this invention to provide means for sealing the ends of cord tapes without reducing their tensile strength.

Other objects of the invention will be obvious or will appear hereinafter.

According to the present invention, the ends of cord tapes are positioned in'overlapping relation within a seal having a lining of plastic material that'exhibits flow under pressure. After the tape has been tightened, thev seal is attened by pressure to force the plastic to contact, bind or penetrate into the cord and into the spaces between the individual fibers of the cords, thereby binding the ends of the tapes to the sleeve and preventing relative movement of the tapes within the seal without substantially reducing their tensile strength. .When tension is exerted in opposite directions on the ends of the tapes within the seal the resistance to Such tension is due in part to the frictional resistance of the tapes with respect to the sleeve that encloses them and in part to the frictional resistance of the contiguous surfaces of the tapes. In one embodiment of the invention the seal is'made of metal or of a rigid .plastic incapable of flow under pressure. embodiment a tubular Vsleeve of metal or the rigid plastic is lined with a plastic which exhibits flow under pressure. In a second embodiment a seal is formed entirely of a plastic which itself exhibits flow under pressure.

For a more complete understanding of the nature and scope of the present invention reference should be had t the accompanying drawings, in which:

FIGURE yl is a perspective View of a carton bound by a cord tape according to this invention;

FIGURE 2 is a cross-section of a blank from which one embodiment of the seal of the invention can be made;

FIGURE 3 is a perspective View, partly in section, of the blank of FIGURE 2 after formation into a seal and used to bind cord tapes; v

FIGURE 4 is a perspective view, of a lseal having an open side and lined with a pressure-Howable plastic;

FIGURE 5 is a sectional view showin-g the seal of FIGURE 4 after application to. cord tapes in accordance with the invention;

FIGURE 6 is a perspective view of another embodiment of the seal of the invention before application to tapes;

In this 5 nijted States Fatet smsen FIGURE 7 is a longitudinal section of the seal of FIG- URE 6 after it has been applied to bind the ends of cord t tapes;

FIGURE 8 is a perspective View of a third embodiment of the seal of the invention before application to the cord tape; and` FIGURE 9 is a perspective View partly in section of the seal of FIGURE 8 after applicationto the ends of cord tapes.

' In general, the invention contemplates two embodiments of a seal for the ends of cord tapes: (l) a seal in which the structural body is formed of a metal, a stiH plastic not exhibiting ilow under pressure, or a vulcanized fiber or the like, all of which are lined, at least where their surfaces will contact the tape, with a plastic which exhibits' iiow under pressure. In the second embodiment, the seal itself is formed substantially entirely of a plastic material which will exhibit flow under pressure.

When the seal is formed of metal, the meal should be selected with respect to its resiliency and resistance to corrosion, such as coated carbon steel, stainless steel, aluminum and its alloys, brass, bronze, tin and the like.

When the structural part of the seal is rformed of a plastic not exhibiting flow under pressure it may be selected from thermoplastic or thermosetting resins or organic cellulose derivatives which exhibit a non-tacky, shape-retaining structure at room temperature, such for example, as cellulose ethers, cellulose esters, polyvinyl resins, polyamids, polyesters, polyacrylonitriles, epoxy resins and the like.

The nature of the plastic exhibiting flow under pressure, which is used as the lining of the rigid seals, or is used as the seal itself, should be selected with regard to the function` to be performed. It is known that purely thermosetting resins, such as urea-formaldehyde, mela-mine formaldehyde, phenol formaldehyde and epoxys are thermosetting resins and in their thermoset state are brittle and do not exhibit any appreciable flow under pressure but, on the contrary, fracture and shatter when subjected to pressure. On the other hand, there is a whole class of cellu'lose derivatives, thermoplastic and thermosetting resins in the thermoplastic state, which do not exhibit brittleness under pressure; but which on the contrary, exhibit the ability to flow and defer-m under pressure. This property of flowing under pressure is `greatly increased by the use of plasticizers, by blends with other soft resins, by use of solvents in minor proportions and by elevating the temperature. Therefore, in the present invention, the plastic used as the yliner for rigid seals or as seals which themselves are capable of cold ow, are selected from the class consisting of- (a) organic-cellulose derivatives such as plasticized cellulose acetate or cellulose acetate butyrate, (b) thermoplastic resins such as polyvinyl acetate or polyvinyl butyral, (c) thermosetting resins in the thermoplastic state such as resorcinol-formaldehyde, and (d) formulated catalyzed alpha-chloro-acrylonitrile and alpha-chloroacrylates, these latter resins polymerizing in a matter of seconds. It is also to be understood that the invention contemplates the -use of plasticizers and solvents as needed to impart to any of these classes of plastics the desired degree of flow which can be readily determined by those skilled in the art.

Referring to FIGURE 1, a carton 10 is bound by means of a cord tape 111, the two ends 12 and 13 of the tape being bonded by a seal generally indicated at 14.

In that embodiment shown in FIGURE 2 the seal may be formed of a fiat sheet 15 of metal or semi-rigid plastic which is united with a layer or coating of pressure-flowable plastic I6l applied to one surface. The sheet 15 is then folded to` form a tubular sleeve 17 as shown in FIG- URE 3 and the overlapping areas formed into a longitudinal seam 18 by spot welding, induction heating, ad-

Patented July 24, 19452` hesives or the like, `depending upon the nature of the material used in the sheet 15.

Referring to FIGURE 3, the ends 12 and `13 of the cord tape are passed through the tubular sleeve in overlapping relation and the sleeve is then subjected to pressure with or without heat, so as to flatten it and simultaneously cause the plastic layer l16 to contact, bind or penetrate the individual cords of the tape. It should be noted that the pressureilowable plastic 16 adheres to the surface of the seal and to the cords of the tape so that the tape is prevented from movement relative to the sleeve 17 and the ends thereof are restrained from movement with respect to each other.

Referring to FIGURE 4 there is shown a seal of the open-edge type, in which a rigid structure 20 is formed of metal or semi-rigid plastic and comprises a longitudinal rib 21 which imparts spring properties to the seal. Preferably, one edge of the seal is upturned to form a flange 22.

The interior surfaces of the seal are coated with a layer of a pressure flowable plastic 23. In application, the two overlapping ends 12 and 13 of the cord tape are overlapped and introduced into the seal through the open side thereof and pressure is then applied to the seal 20 so as to close the seal and cause the plastic lining 23 to contact, bind and penetrate the cords of the tapes, as shown in FIGURE 5.

That form of the invention shown in FIGURE 6 is similar to that shown in FIGURE 3 except that here a multiplicity of short, stiff bristles 24, preferably formed of nylon, are embedded in a pressure-owable plastic layer 25 and project inwardly of the metal or rigid plastic sleeve 26. The bristles may be embedded in the plastic while the sleeve body is still in its flat state such as shown in FIGURE 2 by an operation known in the art as flocking. When the ends 12 and 13 are inserted through the seal the bristles are bent slightly in the direction in which the ends of the tape are moving and upon application of pressure to the seal to flatten it, the bristles are forced into the cords of the tape as `shown in FIGURE 7 and thus increase the holding power of the seal.

In FIGURE 8, the `seal is shown in the form of a flattened S and comprises a body portion 27 of metal or stiff plastic coated on the tape engaging surfaces with a pressure-Howable plastic 28. With this form of the invention, the ends 12 and .13 are not in contact with one another, each end being inserted into one of the loops of the S through the side of the seal. Upon application of pressure to the seal, the pressure-flowable plastic penetrates into the tape as indicated in FIGURE 9 to provide a secure grip. This form of the invention offers the advantage that when tension is applied to the tape there is no possibility of abrading action between the sealed ends thereof. Another advantage of this form of seal is that it may be pre-applied to one end of the tape before the tape is applied to the carton.

In applying all of the seals above described it is advantageous to employ an electrically heated tool for flattening them into contact with the tape inasmuch as the flow of the plastic material into and around the cords of the tape is enhanced by the application of heat. In instances where the tape will be under unusually high tension, it will sometimes be desirable to provide a crimp in the seal rather than merely flatten it.

Having thus described certain preferred embodiments of the invention, what is claimed is:

1. A package tie comprising a exible tape formed of a plurality of parallel cords lying in a common plane, said tape having ends positioned in overlapping relation in parallel planes, a metal sleeve embracing the overlapping ends of said tape, said sleeve having parallel wall sections facing opposite faces of the overlapping ends of the tape, said sleeve being lined with a pressure-flowable plastic, said plastic being intimately conformed about portions of the cords of said tape and penetrating the individual cords of the tape and completely filling the space between the tape and the metal sleeve.

2. The method of securing overlapping ends of a flexible tape formed of parallel cords lying in a common plane comprising embracing the overlapping ends of the tape with a metal `sleeve having a lining of pressure-owable plastic, and forcing the sleeve against the overlapping ends of the tape with suflicient pressure to cause the pressureflowable plastic lining to ow about the cords and penetrate the cords and completely till the space between the sleeve and the overlapping ends of the tape.

References Cited in the tile of this patent UNITED STATES PATENTS 1,175,781 Loudon Mar. 14, 1916 1,263,523 Browning Apr. 23, 1918 2,229,849 Heidebrecht Jan. 28, 1941 2,251,402 Drew Aug. 5, 1941 2,639,479 Dahm May 26, 1953 2,955,339 Richardson Oct. 11, 1960

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