US2878849A - Flexible bags of plastic sheet material - Google Patents

Description

March 24, 1959 D. J. LINGENFELTER ETAL 2,378,849

FLEXIBLE BAGS OF' PLASTIC SHET MATERIAL Filed Sept. 12, 1955 /lvl/Nro/as.` DAN/1. d. L/NsNnsLTR R/CHARU 0. GRO ver? BY THE/R HTTORNYS.

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United States Patent O 2,878,849 FLEXIBLE BAGS F PLASTIC SHEET MATERIAL `Daniel J. Lingenfelter, Glendale, Richard D. Grover, Van Nuys, and Charles A. Forbes, Jr., Los Angeles, Calif., assignors to Polyfab Company, Los Angeles, Calif., a corporation of `California Application September 12, 1955, Serial No. 533,772

3 Claims. (Cl. 15G-.5)

This invention relates to llexible closure devices and flexible'containers for the reception of articles of miscellaneous natures.

- An object of the invention is to provide for various industries and uses flexible bags, which may be transparent or opaque, adapted for the reception of articles ordinarily -iof relatively small size, which bags may be readily opened and closed for introduction and removal of such articles.

Another object of the invention is to provide bags of f "the indicated nature easily formed as an envelope type of structure.

' It is also an object to produce bags or envelopes of the indicated nature, which, when containing various articles, may be readily mounted upon supports such as pegs or hooks and which may also be secured together in vgroups by various securing means such as pieces of cord,

small rings, and the like.

f- More particularly, it is an object of the invention to -femploy, yfor the purpose of holding bags or envelopes of the indicated nature in closed condition, sliderless fasteners of plastic materials adapted to be pressed together and to be easily pulled apart when the bags are to be opened. A further specific object is to use stiifening means at the upper side of such a bag or envelope for suspension of such bag or envelope on a hook or peg envelope produced in accordance with this invention,

`some portions being broken away whereby to illustrate the construction;

Fig. 2 is a vertical section taken on the line 2-2 of Fig. l showing a sliderless fastener employed in the construction in closed position;

Fig. 3 is a view similar to that of Fig. 2, the sliderless fastener having its parts separated 'and thereby placing the bag in open position;

Fig. 4 illustrates three operations in producing a plastic bag or envelope of this improvement, position A indicating folding operations, position B indicating attachment of one member of a flexible sliderless fastener, andy position C indicating attachment of a second member of ailexible sliderless fastener;

Fig. 5 indicates a feature of manufacture wherein an elongated series of flexible bags or envelopes is first produced by folding an elongated strip of scalable ilexible plastic material, which is desirably transparent, heatsealing flexible plastic sliderless fastener strips to oppos ing edges of the folded elongated strip, heat-sealing "opposed walls' of the folded strip transversely to close bag ends, and severing the elongated strip to yield a suo cession of separate bags;

Fig. 6 illustrates a step of inserting a stilening strip or indicia-bearing stub into an elongated pocket at the upper side of each bag, following a severing operation such as indicated in Fig. 5, this ligure also indicating a structure in which sliderless fasteners are omitted;

Fig. 7 is a vertical section as indicated by the line 7 7 of Fig. 6;

Fig. 8 is a View similar to that of Fig. 6 showing a grommet or eyelet applied following insertion of the stiiening strip;

Fig. 9 illustrates successive steps in the production of a t fastener to the front fold in position to co-operate with the first member of the sliderless fastener; and

Fig. 10 indicates an operating step.

Having reference first to the `forms seen in Figs. l, 2, and 3, a thin, flexible plastic sheet or body member, preferably transparent, and desirably in the form of a ilattened tube indicated at 10 is employed to form the envelope or bag shown. However, a wide strip may be employed whose portions are folded to yield the same configuration as that produced from the tube. In the case of a tubular body member 10, a portion adjacent one edge of the flattened member is cut away at 12 as indicated at position A in Fig. 4, so as to leave spaced opposing edges. In the case of the folding of a wide strip as the body member 10, the top edge portion of position A of Fig. 4 is folded over to be correspondingly opposed to the upper edge portion of the lower section and provide the same space 12. In either of these arrangements a back wall 14 is provided and a main front wall 15 also is provided. The upper portion above the space 12 is thus in the form of a ilap 16. In either event, there is thus provided a top fold or edge 17 and a bottom fold or edge 18 for the resultant bag or envelope. In practice the ends of the resultant bag or envelope are cross sealed at 20 through ahe medium of heat-sealing between the lower fold 18 and the longitudinal space 12, such sealing being accomplished through the medium of hot dies 21 and 22 applied to the outer sides of the back and front walls 14 and 15, somewhat as diagrammatically indicated in Fig. 10, or the lower or back member 21 may be a bed.

The llap 16 is similarly sealed at 23 to the back wall .14 to provide an elongated pocket 24 which is adapted to receive a stiffening strip 25 which may also constitute an indicia strip carrying parts names, instructions, or other desired information. Instead of heat-sealing the ends of the elongated pockets 24 to retain the stiffening t strip 25, an eyelet or grommet 26 may be positioned at the middle of the flap 16 to pass through the flap 16, the strip 25 and the adjacent portion of the back wall 14. The resultant opening 26a serves for the hanging or positioning of the envelope or bag upon any appropriate hook or peg. f y

To provide positive closure means for the bag, a twopart flexible, sliderless separable fastener is used, as probably best seen in Figs. Zvand 3. This sliderless fastener comprises an inner strip 30 and an outer strip 32, both strips 30 and 32 extending the full length of -the bag, the upper portion of the inner strip 30 being t 3 back wall `14. This mounting and sealing of the inner fastener strip 30 may be effected in a separate operation by which the lower end of the ap 16 is sealed to form the pocket 24, or it may be effected simultaneously with the attachment of the outer strip 32 by a common die 33 shown in Fig. 4 at position C, whereby the sealing line 34 is produced by the hot die 33. As illustrated in Fig. 4 at position C, the die 33 has two legs 33a and 33b, the leg 33a being preferably somewhat longer than the leg 33h, whereby to accommodate a so-called former strip 35 which is in effect an insulating strip disposed behind the front wall 15 to avoid sealing of the front wall `15 to .the back wall Y14 when the die 33 is applied. As will be apparent, in the application Vof the hot dies, the back wall 14 will bear against any suitable bed or support (not shown). While the sealing at 23, together with the .sealing of the upper edge of the inner fastener strip 30, and the sealing of the outer strip 32 at 34 may be made simultaneously with the die 33 and its two legs 33a and 33b, these operations may, of course, be separately performed, but not preferably so.

Thus, in position A of Fig. 4, there is illustrated the cutting or folding of the body member to leave the space 12 between the opposite edges of the lower front member 15 and the upper flap member 16; in position B there is illustrated the sealing of the upper edge of the fastener member 30 Aand the sealing of the llower edge Vof the ap member 16 together and to the vback wall 14, and in position C there is illustrated the sealing of the outer fastener member 32 to the upper edge of the front wall 15, as well as an indication of simultaneously and preferably sealing the upper edge of the fastener' strip 30! to the lower edge of the flap 16 in "to receive the tongue 36. These parts are shaped to effect a dovetailed arrangement so that the flexible tongue 36 snaps into the groove between the ribs 38 by reason of slight yielding of these parts to effect a dovetailed joint, which joint, however, may be readily separated by slipping the thumb nail behind the upper edge of the outer strip 32 and pulling it outward away from the tongue 36. This joint, when closed, adequately maintains the closed relationship of the bag. The ends of the fastener strips 30 and 32 are sealed to the bag walls 14 and 15 by extensions of the transverse seals 20, as probably `best indicated in Fig. 5, and desirably the top edge of the outer fastener strip 32 at both ends is further sealed by an overlapping sealing 40 as seen in Figs. l and 5.

Figs. 6, 7 and S illustrate the insertion of the stiffening or indicia strip 25 into the elongated pocket 24 at the top of the envelope body 10 behind the Hap 16, and the eventual placing of the grommet 26'. These Figs. 6 to 8 further illustrate a simplified form of envelope structure in which the sliderless fasteners 30 and 32 of the form of Figs. l to 5 are omitted. In this instance a mere slit indicated at 42 is provided between the upper edge of the front wall 1S and the lower edge of the 'iiap 16, the bag being openable at this slit for the insertion and removal of small parts or other articles.

In Fig. 9 there is indicated a further variation of the bag structure, the sliderless fastening strips 30 and 32 being used but somewhat differently arranged. As seen in position D of Fig. 9 a wide plastic strip 43 is used as the bag or body member and is folded once to provide a back wall 44 and a .front wall 4S corresponding with "theback and front walls 14 and 15 of the other forms, 'this `fold 46 .corresponding with the fold 18 of Figs. 1

to 5. As indicated in position E in Fig. 9, the upper may correspond with the spacing 12 shown in Fia. 4. position A. With this structure, as illustrated in position F, the upper edge portion of the inner fastening strip 30 is sealed at 47 at the top of the back wall 44 and the lower edge of the outer fastening strip 32 is sealed at 48 to the upper edge of the front wall 45 so that the tongue 36 and the ribs 38 will co-operate in the same manner as indicated in Figs. 2 and 3. 'The attachment of the fastening strips 30 and 32 may be effected in the same manner as described for the structure of Figs. l to 5. The ends of the bag will be vsealed as indicated at 20 in the other forms, and the bag will be opened and closed through the medium of the fastener strips 30 and 32 for the other form. However, with this structure there s no top flap 16 and pocket 24 to receive any type of stiffening or indicia strip 25 as previously described.

In practice, the longitudinal vsealings lat 23, 34, 47 and 48 are preferably produced as initial sealing strips. the transverse seals 20 being subsequently produced by the dies 21 and 22 prior to severing to yield a plurality of bags or envelopes from the same elongated folded body structure 10. The short reinforcing seals 40 for the ends of each outer fastener strip 32 at the upper edges thereof would ordinarily be made before sealing the bags transversely.

The synthetic plastic material which is ,used in the production of bags or envelopes of this invention is of course one which, as has Ibeen indicated, is thermoplastic so that, when heat is applied to the sealing lines as indicated, adjacent plastic portions are sealed together by the incidental fusion. Such plastics are very well known on the market, and any of vthern may be used for `this purpose. The same is true of the sliderless fastening strips 30 and 32. Appropriate plastics which may be mentioned include those synthetic plastic resins known in the trade as polyethylene, polyvinyl chloride, polyvinyl acetate, polyvinyl chloride-polyvinyl acetate :c0- polymers, polyvinylidene chloride copolymer, rubber hydrochloride, nitrile rubber, laminations of thermoplastic films to other plastic lms or to non-plastic materials such as paper or metal foils, similar vinyl type resins, and the like. Such materials are readily purchasable in tubular, sheet, and folded sheet forms for uses such as the present, such sheets and tubes offering more than .adequate strength for the purposes of this invention.

Such other modifications than those indicated may be made within the scope of this invention as are defined by the patent claims.

We claim as our invention:

l. A exible plastic bag including: a liexible plastic sheet folded horizontally to produce a bottom at rsuch fold and to provide a back wall and an opposing `front wall, such Walls having side edges opposed and secured together in heat-sealed contact with each other to provide closed sides of the bag, said back wall being taller than the front wall and extending beyond the upper edge of the front wall; and an integral flap across the `top of said back wall and folded over forward and downward, the lower edge portion of said ap being heat-sealed to said back wall adjacent the upper edge of said front wall and forming an elongated transverse pocket.

2. A flexible plastic bag including: a synthetic plastic sheet folded horizontally to produce a bottom at `such fold and to provide a back wall and an opposing front wall, such walls having side edges opposed and secured together in heat-sealed contact with each other to provide closed sides of the bag, said back wall being taller than the front wall and extending beyond the upper edge of the front wall; a first plastic closure member heat-sealed across said upper edge of said front wall; a co-operatrt second plastic closure'member seat-sealed across an upper portion of said back wall in position to co-operate with Saidi-st closure memben-andan integral aP am smalto the top of said back wall folded over forward and downward and heat-sealed at its lower edge to said back Wall adjacent said second closure member and forming an elongated transverse pocket for receiving a strip.

3. A bag as in claim 2 including: a. at strip in combination therewith mounted in said transverse pocket; and an eyelet extending through said ap, said back Wall and said strip for securing said strip in said pocket and for supporting the bag on pin means.

References Cited in the file of this patent UNITED STATES PATENTS 1,136,138 Izett Apr. 20, 1915 6 McCluer May 1, 1917 Martin Ian. 6, 1925 Boyes Dec. 8, 1925 Stcmber Ian. 6, 1931 Spotts Sept. 30, 1941 Schade July 28, 1953 Sharat Jan. 19, 1954 Marcus Feb. 1, 1955 Langer July 17, 1956 Post Apr. 23, 1957 Oliva et al Sept. 24, 1957

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