US2896397A - Paper strap and method for making same - Google Patents

Description

July 28, 1959 H. K. STEEN 2,896,397

PAPER STRAP AND METHOD FOR MAKING SAME Filed May 25, 1955 3 Sheets-Sheet l INVENTOR.

Hcrford K. Sreen Arromvn July 28, 1959' sTEEN 2,896,397

PAPER STRAP AND METHOD FOR MAKING SAME Filed May 25, 1955 s Sheets-Sheet 2 INVENTOR. Hdrford K. Steen A TTORNE Yj y 1959 H. K. STEEN 2,896,397

PAPER STRAP AND METHOD FOR MAKING SAME Filed May 25, '1955 5 Sheets-Sheet s Fig. 14.

Fig. I 15.

INVENTOR.

Hqrford K. Sfleen ATTORNEYS United sates Hal-ford K. Steen, Newburgh, N.Y., assignor, by mesne assignments, to Interstate Bag Company, Ina, a corporation of Virginia Application May 25, 1955, Serial No. 510,894

9 Claims. (Cl. 57-l'54) This invention relates to paper straps or ribbons and the manufacture thereof. While paper straps or ribbons according to the invention are adapted for a wide variety of uses, some types have been contrived especially for use as handles for paper shopping bags and will be illustratively described in connection with that use.

For many years standard shopping bag handles have been made of paper twisted into a twine of circular cross section, and these have been secured to one or more walls of the paper bag by the use of suitable adhesive, or by mechanical means such as staples. There are a. number of objections to handles of this type.

A handle of small circular cross-section, given a sufiiciently heavy load within the carrying capacity of present day shopping bags, has the drawback of digging into the hand and making a loaded bag uncomfortable to carry. Since the handle ends moreover, make only a line of contact with a flat surface, it is diflicult to secure them to the bag walls, and thus far the most satisfactory means for attachment is to bind the handle ends to the bag walls by the use of a strong paper strip running parallel to the top of the bag which is pasted to the bag over the handle ends. The amount of paper strip thus used is considerable and the operation of putting on the strips (or patches) adds substantially to the cost of the finished bags.

Flat handles are thus preferable to round handles, but flat paper handles as heretofore constructed have also been subject to important shortcomings, especially since under certain stresses such as occur when a heavily loaded bag is swung or twisted, the outermost fibers of the handle fail in tension unless excess material is em ployed. In this respect all previously known flat handles are inferior to the conventional round type.

In accordance with the present invention a novel form of fiat handle is provided which combines into one structure adequate and. uniform strength, economy of material and manufacture, strong and dependable adhesive union with the flat bag body, a comfortably broad carrying surface, and a satisfactory degree of flexibility.

The handle of the present invention is desirably formed of a strong, flexible paper such as kraft paper, although other forms of paper or even plastic sheet material may be used.

Strong paper, such as kraft, the use of which is preferred, consists almostentirely of matted or felted cellulose fibers, plus such residual lignin and sizing material as may be present. Under the conditions of the present method, i.e., of moisture and pressure, the paper strip started with may be reshaped and caused to retain substantially any shape desired due to interlocking folds or flutings that are formed and aided by a certain degree of re-orientation and re-bonding of the fibers.

The paper strap or ribbon of the present invention is desirably formed by continuously feeding and simultaneously twisting a web of flat, water-impregnated paper into a loosely twisted or spiral form (loose as compared atent 2,896,397 Patented July 28, 19,59

with the tightness required for the making of twine) and at the same time compressing and forming the twisted web into a ribbon of uniform thickness from edge to edge (or at least one having blunted side edges) through the application of suitable forming and confining pressure, which ribbon has a width several times as great as its thickness, but only a fraction of the width of the original web which was twisted to form it.

In addition to the advantages pointed out above, a ribbon of this kind has the additional merit that it can be pre-formed with local deformations for special purposes as required.

Tears are most likely to start in the side edges of a flat ribbon. This is particularly true if the edges are thinner than the main body, and also if the edges are under abnormal strains as compared with the remainder of the structure. The novel ribbon of this invention has the advantage that it may be formed so as to be extremely resistant to transverse tearing, both because the extreme marginal portions are at least as thick as any other portions of the ribbon, and because the edge portions are free from abnormal peripheral strain and do not therefore present a condition favoring incipient tears.

While emphasis has been put upon ribbon-like structures having especial utility as bag handles, the invention is not confined to structures having flat faces nor having as great disparity of width to thickness as indicated above. A twine which is loosely twisted, fed, and continuously compressed by a pair of feeding and forming rollers has the advantage over conventional twine which is shaped solely by twisting that the peripheral fibers are free from circumferential strain. My improved strap may range in cross-section from elliptical to rectangular and in every such form it presents a broad face for engagement with the hand. It will be noted that since the twisted web reaches the rolls in a form having a substantially circular crosssection, the shape of the resulting product must be such that it has greater width than thickness, and the forming space between the rolls must be correspondingly shaped. It is not essential that the product be of uniform thickness from edge to edge, nor that it be of maximum thickness throughout the central longitudinal zone. The twine or ribbon may be longitudinally ribbed on one or both faces, or it may be thick along its margins and comparatively thin along the longitudinal central zone. It may also be non-uniform in cross-section along its length, as for example, it may be of oval, or of substantially round cross section with end portions or other zones formed of flattened rectangular cross-section.

For a complete understanding of my invention, refer ence may now be had to the following detailed description taken with the annexed drawings in which- Figs. 1, 2 and 3 show on an enlarged scale the strap material which has been remoistened and has been care fully unfolded;

Fig. 1 shows the material of a strap which, before twisting, consisted of a two-ply web, the web having been folded on itself along a longitudinal axis;

Fig. 2 shows the material of a strap which, before twisting, consisted of a single-ply web;

Fig. 3 shows the material of a strap like that of Fig. 2 but with the material progressively unwrapped more and more toward the lower end thereof;

Fig. 4 is an end view of the material of Fig. 1, looking up the sheet, as indicated by the line 44 and the associated arrows;

Figs. 5 and 6 are end views of the material of Fig. 3, looking down and up the sheet, respectively, as indicated by the lines 55 and 6-6, and the associated arrows;

Fig. 8 is a view on line 88 of Fig. 7 showingthe.

combination of die-and-draw rolls;

Fig. 9 is a view showing die-and-draw rolls appropriately shaped for making an improved strap or strap segment of elliptical cross-section;

Fig. 10 shows a further modification of die-and-draw rolls for producing a further modified product;

Fig. 11 is a view similar to Fig. 7, showing an alternative apparatus and process;

I Fig. 12 is a plan View of a form of strap illustrative of the invention, having broad, fiat ends,- and a comparatively thick and narrow intermediate portion;

' Fig. 13 is a plan View of a form of strap, illustrative of the invention, having comparatively thick and narrow ends, and a broad, flat intermediate portion;

Fig. 14 is a view in elevation of a bag, partly broken away, and broken away intermediate its ends for compactness, in which the strap of Fig. 12 is utilized as a handle;

Fig. 15 is a fragmentary view in elevation of a bag, partly broken away, in which the strap of Fig. 13 is used as a handle.

Referring to Fig. 7, a reel of water-impregnated kraft paper web is shown at It the same being mounted for rotation about an axis a-a normal to its end faces so as to unroll the same, and simultaneously for rotation about a second axis b-b at right angles to the first, and which extends in the direction of web feeding, for imparting a twist to the Web. The web may be a single ply web or a plural ply web, i.e., longitudinally folded, or even composed of a plurality of distinct, superposed plies, but in every instance a single winding is formed prior to shaping. The 'web is continuously withdrawn from the roll 10 and fed between a pair of rolls 11, 11a which function both as draw rolls for unrolling and advancing the web, and as die rolls for shaping and compressing the web under a very substantial pressure. The rolls 11 and 11a are driven in opposite directions to one another by means not shown. Such means are, however, capable of bringing rolls 11, 11a together with considerable force, and enable the rolls to move toward one another the requisite amount to assure the firm compression and molding of the twisted web into a compact ribbon of rectangular cross-section. The engagement by said rolls 11, 11a of the paper causes the same to be withdrawn from the reel 10 by causing the reel to rotate about its axis aa. The reel 1% is also rotated about axis bb which extends parallel to the direction of feed of the ribbon 12, thereby twisting the tape into a helical form which assumes a narrowing, conical shape as it approaches the draw rolls 11, 11a.

The rolls do not exert a mere flattening pressure upon the paper cone but serve rather,by confining the paper, to shape and form the twisted paper into a ribbon 12 of rectangular cross-section, pressing the upper and lower surfaces toward one another, but also confining and forming the side surfaces. This is accomplished by forming a molding space between the peripheries of the rollers. The roller 11a is formed with a circumferential groove 13 of rectangular cross-section. The roller 11 is of simple cylindrical shape and has its marginal portion adapted to fit snugly between the parallel side walls of the groove 13, as shown in Fig. 8. This causes the twisted paper to be gathered and formed into a plurality .of creases or flutings A, which extend in from the end of the web, and B, which extend in from the right edge of the web. All the ilutings would eventually run off at the left edge if the strap were not cut off into lengths. The flutings interfit with one another to form a compact, flexible, square-cornered band or strap 12, as shown in Fig. 4. Because of the interfitting of the various longi- 4 tudinal folds or flutings, and the strong character of the paper employed, the strap 12 possesses great strength, especially since some molding of the non-fibrous materials and some interbonding of the many surfaces in contact with one another takes place.

The formation of the strap is facilitated by moistening the paper web prior to the action of the rolls 11, 1111. In the method illustrated in Fig. 7, the web is moistened prior to winding it onto the reel 10. It is then fed to the rolls 11, 11a before it has had a chance to dry out.

In Fig. 1 the strap, now unfolded, was made from a two-ply web, and these plies are still shown superposed in the figure. An upper fold C joins a lower fold D along a fold line B. Fold C terminates along line E. The heavily compressed wet paper does not tend substantially to recover from the form to which it has been reshaped by the rolls 11, 11a. The non-fibrous constituents of the paper, when dried, cause the paper to become set and to retain the rectangular ribbon shape, while permitting the ribbon to be bent and folded as desired. The rolls 11, 11a are knurled at F for the purpose of improving the traction upon the strap and also to facilitate interbonding of the folds, such knurling-resulting in giving the strap a slightly ribbed effect as shown'in Fig. 3. The knurl marks persist when the strap has been exfoliated. However, the knurling may, if desired, be omitted and a satisfactory result had.

As the strap is formed, it is cut into desired lengths by means of cutting rolls 15, 16, the former being provided with a cutting blade 15', and the latter having a hardened steel surface. The ribbon travels to the cutting point at the linear speed of the edge of knife 15'.

The cut strips 12a of ribbon 12 are fed away from the cutting station by a segment 17 and a roller 18 opposed thereto. The segment 17 is of larger radius than the radius of the cutting edge of the knife 15. The segment 17 is driven at the same rotary speed as the roll 15, and hence at greater linear speed than the knife edge. The parts are so timed that the leading end of the ribbon 12 is advanced beyond the couple 17, 18, while still free of the segment 17 and roll 18, prior to cutting. At the instant of completion of the cut, the segment 17 proves effective to seize the cut length 12a and feed it forward at increased speed to subsequent instrumentalities (not shown) which continue the advance of the strap at undirninished speed. The couples 11, 11a, 15, 16 and 17, 18 are shown closer together than they are in actual practice.

The draw-die rolls act in an entirely diiferent manner from mere flattening rolls. Rolls of the latter type would effect a mere pressing action, adapted to produce a ribbon having the cross-sectional shape of a flattened tube. The action of the draw-die rolls of the present invention is an orderly folding and shaping of the material of the ribbon into a series of interfitting longitudinally extending ilutings in such a manner as to preserve the strength of the material and to prevent any tendency of the strap to elongate as by slippage of the folds over one another. The compression of the ribbon to reduce its thickness, tends to increase the width of the ribbon. This however, is resisted by the side walls of groove 13, so that in the end the ribbon is molded to the shape of the entire forming space.

The number of turns given the paper strip or ribbon may be varied within limits. Thus far I have found that.

from three to ten turns per linear foot of the complieted strip may be advantageously provided, it being noted that the pitch is controlled by the relation of the rate of feed of the draw rolls 11, 11a to the rate of rotation of the reel frame about the axis b-b. In Fig. 2 it will be noted that the piece of unfolded strap is placed with the fluting substantially vertical of the sheet, and 'with the longitudinal axis of the ribbon at a slight angle thereto.

Fig. 11 shows an alternate arrangement in which the paper ribbon 20 is withdrawn from a roll 21, is moistened" in moistener 22, and formed into a helix 20 by die rolls 23, 23a which are provided with two motions of rotation, i.e., about the respective axes a'a, a"-a, normal to the faces of the rolls, and about an axis coincident with the longitudinal axis of the ribbon 20. The rollers 23, 2301 are duplicates of the rollers 11, 11a. As in the case of Fig. 7, the strap having been formed by the action of the rolls 23, 23a, such strap is severed by means of cutoff knife 24, and an opposed roll 25, similar to knife 15' and roll 16. The couple 24, 25 turns in unison with rolls 23, 23a about axis bb'. The knife 24 is timed to cut the ribbon at the instant when the ribbon is flat; i.e., when the axes a--a and aa" extend horizontally. Segment 26 and roll 27 duplicate the corresponding parts 17, 18 of Fig. 7.

The apparatus of Fig. 7 or of Fig. 11 is adapted to make a strap of uniform width and uniform thickness, as shown in Figs. and 6. Such a strap is well adapted to serve as a bag handle. It provides fiat, broad ends for adhesion to the bag body, and a flat, broad hand engaging portion. Straps of this: uniform, cross-sectional shape may be formed by varying the shape of the forming space as seen in Figs. 9 and 10.

It is at times desirable to provide straps of varying cross-section. An example of this is shown in Figs. 12 and 14. The strap length 12b is shown of normal width and thickness in sections 30, but abnormally wide and abnormally thin in sections 31 and 32. The strap 12b, as seen in Fig. 14 is applied to a wall of a paper bag 33 near the mouth thereof. The sections 31 and 32, which are wider than normal, are adhesively secured to the bag wall and to an overlying patch 34. The two outer sections 30 extend vertically upward. The wide, thin sections 31 and'32 are bent or folded. The section 30, which constitutes the hand grip portion, extends horizontally.

The strap 12b of Fig. 12 may be made on the machine of Fig. 7, or on the machine of Fig. 11 by suitable modification of the rollers 11, 11a or 23, 23a. For forming the sections 30, the rolls 11, 11a would have the crosssectional configuration shown between the rolls 39, 39a in Fig. 9, but wherever one of the wider, thinner sections 31, 32 is to be formed, the channel 13 of roll 11a would be widened to provide a forming space like that shown between rolls 40, 40a of Fig. 10, and the periphery of the roll 11 would be correspondingly widened. Wherever the channel is wider, the strap spreads into the wider span and automatically becomes thinner under the yielding pressure of the rolls 11, 11a.

Another variation is found in Figs. 13 and 15. Here the strip 120 is formed with ends 35 of normal width and thickness and with an intermediate body portion 36 which is extra wide and thin. The variation of crosssection is secured in the manner already pointed out by varying the shape of the forming space between the forming rolls. The strip 120 is shown applied as a handle to a bag 37 in Fig. 15. The ends are adhesively secured to a bag wall and to an overlying patch 38.

As has been indicated, the uniform cross-sectional configuration of the strip may be changed by uniformly changing the shape of the forming space between the die-and-draw rolls. Fig. 9 shows the formation of a strap or twine 30 into elliptical or oval cross section. Die rolls 39 and 39a, corresponding to rolls 11, lla'of Fig. 7, or to the rolls 23, 23a of Fig. 11, are formed peripherally with complementary, semi-elliptical grooves whose major diameters extend axially of the rolls, and whose minor diameters extend radially of the rolls. A strap of the character produced by these rolls has substantial practical advantages over ordinary twine, among them being (1) broader surface contact with the hand for a given cross-sectional area, (2) steeper pitch to the spiral convolutions and hence less tendency to elongate, and (3) looser twisting with resultant reduced circumferential tension of the fibers.

The bath 22 through which the paper ribbon 20 passes prior to the twisting and molding operations may, if desired, contain suitable adjuncts having a plasticising or other action. In many instances the use of a diluted glycerine solution is advantageous in assisting the twisting and molding operations. If desired suitable sizing or adhesive material may be used in the bath 22 to promote the bonding together of the fibers. In the operation of the method to date, no problem has been presented in the drying of the straps directly following their formation, but it is obvious that the straps upon formation may be subjected to drying conditions if these are found necessary. The practice with die rolls 23, 23a may be operated at higher than room temperatures to increase the molding action if desired.

While certain preferred embodiments of the invention have been illustrated and described in detail, it is to be understood that changes may be made therein and the invention embodied in other structures. It is not therefore, the intention to limit the patent to the specific construction illustrated, but to cover the invention broadly in whatever form its principles may be utilized.

I claim:

1. A paper strap consisting of a single winding of concurrently crumpled and loosely twisted paper having a plurality of twists per linear foot, and compressed along two cross sectional dimensions to a permanent form having a width of several times its thickness, but of appreciable thickness and with blunted side edges, the material of the strap being longitudinally folded in a plurality of fiutings extending in the general direction of the longitudinal axis of the strap but making an angle thereto.

2. A strap according to claim 1 in which at least one side of the strap is knurled.

3. The strap according to claim 1 having from three to ten twists per linear foot.

4. The strap according to claim 1 in which said material is kraft paper.

5. The strap according to claim 1, said. strap being of substantially rectangular cross-section.

6. A paper strap or ribbon as set forth in claim 1 in which the strap is of substantially elliptical crosssection.

7. A paper strap or ribbon as set forth in claim 1 having predetermined major lengths of normal width and thickness, and other predetermined lengths of greater than normal width and less than normal thickness.

8. The method of forming a paper strap which comprises, providing a single broad web of strong, tough paper, impregnating the paper with liquid to render it appreciably plastic, twisting the wet web into a loose, helical form of high pitch, and progressively compressing the twisted web transversely as it is twisted, while confining it laterally, to produce a strap of predetermined, permanent, compact flattened cross-sectional configuration having a width several times its thickness.

9. The method of forming a paper strap which consists in moistening paper or the like to render it appreciably plastic, twisting the paper loosely to form a single helix, and simultaneously with said twisting of the ribbon compacting the helix to form a solid flattened strap having a width several times its thickness, said compression taking place in two dimensions crosswise of the strap.

References Cited in the file of this patent UNITED STATES PATENTS 437,386 Williams Sept. 30, 1890 1,994,057 Wallach Mar. 12, 1935 2,037,205 Barnum Apr. 14, 1936 2,532,923 Kitchen Dec. 5, 1950 2,597,918 Boersma et al. May 27, 1952

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