US2707367A - Twine and process of preparing the same - Google Patents

Description

. y 3, 1955 J. c. PULLMAN 2,707,367

TWINE AND PROCESS OF PREPARING THE SAME Filed Feb. 21, 1951 2 Sheets-Sheet l INVENTOR mar/ c, Fuzz/v4,

2%. T- A ATTORNEY May 3, 1955 J. c PULLMAN 2,707,367

TWINE AND PROCESS OF PREPARING THE SAME Filed Feb. 21, 1951 2 Sheets-Sheet 2 INVENTOR.

JOSEPH G. PULL/WIN,

ATTORNEY United States Patent TWINIE AND PRGCESS OF PREPARING THE SAME Joseph C. Puliman, Stamford, Comm, assignor t American Cyanamid Company, New York, N. Y., a corporation of Maine Application February 21, 1951, Serial No. 212,065

11 Claims. (Cl. 57-440) This invention relates to a process. for producing tape and/ or twine and, more particularly, to a process of producing glass fibrous strand'twine in which the glass strands are embedded in an adhesive material coated on a paper web, covered with another layer of paper to form a fiat assembly and twisting said assembly into a twine. Still further, this invention relates to a process .for preparing twine in which the flat assembly mentioned hereinabove is pressed so that the paper webs form corrugations with the glass strands prior to the twisting of the paper strand assembly to form the twine.

One of the objects of the present invention is to produce a glass twine which will have general utility as a twine but which will be particularly useful as a binder twine and baler twine. A further object of the present invention is to produce a glass'twine which can be readily substituted for natural twines such as those generally referred to as sisal twines. A still further object of the present invention is to produce glass twine by superimposing a plurality of parallel glass fibrous strands. on a paper web coated with an adhesive material, embedding the strands into the adhesive coating on the paper and covering said strands with another paper web, uniting the strands, paper and adhesive into a hat assembly, thereutter twisting the assembly into a twine. A still further object or" the present invention is to apply pressure to the aforementioned fiat assembly in the course of the web assembly production so as to form corrugations with the strands and paper web prior to the twisting of. the paper-strand into a twine. A still further object of the present invention is to use as the adhesive material a thermosetting synthetic resin adhesive wherein the process for the manufacture of the twine can be further modified after the twine has been formed by adding the step of heating the twine so as to cure the thermosetting resin in. the twine. These and. other objects of the present invention will be discussed more fully hereinbelow.

Natural twine generally referred to as sisal twine is becoming increasingly short in supply and the .price of said natural twine is increasing steadily so that it is becoming a virtual necessity to find a synthetic twin'ewhich will be satisfactory for all of the general applications to which the natural twine is put. I have discovered that I can combine a plurality of parallel glass fibrous strands with an adhesive coated paper web and cover the strand embedded adhesive coated paper with an additional layer of paper andform a twine which will have greater strength per unit weight than the natural twine and yet can be produced for far lower cost than the cost of natural twine. 'lIhe glass fibrous strands which may be used in the practice of the process of the present invention are made up of a great plurality of individual glass filaments which are combined to form the strand. The process for the preparation of these glassfibrous filaments and strands well known in the art as represented by the U. S. Patents 2,133,236, 2,133,238, and 2,175,225, amongst others. These filaments are generally'of extremely small diameter in the order of. magnitude of about 0.0002- LIA ice

0.0004 inch and are combined to form :a strand having a diameter or about 0.04 inch since there are generally about 200 or more filaments used to form. a single strand. These glass strands have exceedingly high tensile strength and, in fact, have greater tensile strength than steel wire per unit weight. These strands, on the other hand, cannot be used directly to form twine because they do not have the flexibility which steel wire has nor do they have the flexibility which natural fibrous: twine has. A further shortcoming of the glass fibrous strands resides in the fact that, if a twine were to be made from the glass strands without any protective coating surrounding the strands, the continuous rubbing of one strand against the other would result in a breakdown of the individual strands and eventually a breakdown of the entire twine. A still further shortcoming of ordinary glass strand twine resides in the fact that the flexibility in small arcs is so low and the attrition so great that it is nearly impossible to produce knots having adequate knot strength with such twine without experiencing continuous breaks in the twine. This is due to the sharp, sudden curve through which the twine is bent in knot tying. I have discovered that by coating a paper web with an adhesive composition, superimposing a plurality of parallel glass strands on the paper web, embedding the strands in the adhesiveon the web and covering the strand embedded paper with another layer of paper to form a fiat, unitary assembly, I can twist said assembly into a twine which can be knotted and tied and which has extremely marked flexibility and which strands being separately isolated from one another with the protective coating of adhesive have no opportunity to rub against one another, which rubbing would normally result in the disintegration of the twine.

There are a plurality of ways in which this twine may be fabricated. Each of these minor departures from the essential concept of the applicant are mere modifications, a few of which are set forth hereinbelow. Basically, it is preferred that the adhesive material be applied directly to the paper web before the glass strands are applied to the paper but if one so desired, the adhesive could be applied after the strands had been superimposed on the paper web or the adhesive could be applied to the web simultaneously with the glass strands or the glass strands. could be coated with the adhesive composition and thereafter the resin coated strands could be applied to the paper web.

A still further embodiment of this invention resides in the modification, wherein the glass fibrous strands are placed in parallel positions on approximately one-half the width of the resin coated web whereupon the web can be folded by means of a plow-like device so as to cover the strands and to form a flat, unitary assembly of paper, adhesive and glass fibrous strands. Still further, one could superimpose a great plurality of fibrous strands on a wide paper web coated with adhesive and thereafter superimposing a second sheet on the strand embedded lower web and by slitting this wide web assembly into a plurality of narrower webs of desired width, one could proceed to twist each of the narrower webs into the desired glass twine. Still further and, as a preferred embodiment of the present invention, one could make use of a pressing device in the nature of a pair of rollers covered with a resilient material which would force the upper and lower paper webs together to form corrugations with the glass strands. Care must be taken in the selection of the pressure rollers to insure that the fibrous strands are not damaged while the unitary assembly is being pressed into a corrugated form. For this. reason, it is advisable to use a combing wheel which is firm and resilient and yet sufficiently pliable so. as to avoid damaging the strands. Still other embodiments of this invention will become obvious to anyone skilled in the art and, for this reason, further specific enumeration of detail is considered unnecessary. Each of these embodiments are intended to be included within the scope of the appended claims.

Reference is made to the accompanying drawings which serve to illustrate further the concepts of the present invention.

Fig. l is a side elevational view of a suitable arrangement for the preparation of the tapes to be used in the twine fabrication. Fig. 2 is a perspective view of a part of Fig. 1 showing in greater detail the fabrication of the tape to be used ultimately in the twine manufacture. Fig. 3 is a front elevational view of the rubber covered rollers used to press the upper and lower webs together with the glass strands and adhesive therebetween. Fig. 4 is a side elevational view of Fig. 3. Fig. 5 is a perspective view of a resin coated web upon which glass strands have been superimposed in readiness for the subsequent steps in the twine fabrication. Fig. 6

is a perspective view of one portion of Fig. 5 in which the lower web is folded over the glass strands that are embedded in the adhesive on the web. Fig. 7 is a cross sectional view of a section of the tape illustrated in Fig. 6 or 2. Fig. 8 is an enlarged cross sectional view of Fig. 6 after the tape has been passed through the companion rubber covered rollers to form the corrugations. Fig. 9 is an enlarged cross sectional view of a portion of Fig. 8. Fig. 10 is a perspective view of the claimed product, showing the twisted structure of the twine with a cross-sectional view of the end thereof.

In Fig. l the symbols are used to identify the following components illustrated: 1 is the roll of paper tissue used as the upper web. 5 is the roll of paper tissue used to form the lower web. 3 is the spool or creel providing the plurality of glass strands. It! is the adhesive material in a suitable container into which the conveyor roller 7 dips and carries adhesive to the applicator roll 8 which, in turn, applies the adhesive material to one face of the lower web 6, which passes around the combining roller 12. At the same time, the glass strands 4 are drawn from the spool 3 through the reed 13 and united with the lower web 6 and the upper web 2 as they pass through the combining rollers 11 and 12. The resultant tape 14 is passed through the rubber-covered rollers 15 and 16, which apply sufiicient pressure to the tape 14 so as to produce a series of corrugations in the tape 17. The tape may then be wound into a reel for subsequent storage or may be led directly to a conventional twisting machine. The reed 13 contains a great plurality of dents through which the individual glass strands are fed so that the strands are kept in parallel alignment as they are being positioned between the upper and lower webs 6 and 2. In Fig. 2, the symbol 7 represents the adhesive conveyor roll carrying the adhesive 10 to the adhesive application roll 8. The adhesive is applied to the face of the web 6 which is carried up and around the roller 12 and is combined with the glass strands 4 and the upper web 2 as the three components are passed between the combining rolls 11 and 12. The resultant tape 14 is illustrated in a partial section to show the individual strands 4 embedded in paral lel relationship in the adhesive 10 on the lower web 6 and covered with the upper web 2. In Fig. 3, the rubbercovered rolls 15 and 16 apply sufiicient pressure to the tape 14 made up of the upper web 2, the lower web 6, the glass strands 4, and the adhesive 10 so as to unite the individual components into a unitary structure which has a plurality of corrugations in parallel alignment produced by the presence of the glass strands between the upper and lower webs. Fig. 4 shows a side elevational view of Fig. 3 in which the tape 14 passes through the rubber covered rollers 15 and 16 to produce the desired corrugated efiect. Fig. 5 represents one of the modifications of the process illustrated in Fig. l in which a lower web 6 is used as the sole web and upon which the adhesive is applied and the glass strands are embedded in a series of disconnected parallel groups, each of which can be separated into individual tapes at the lines 18 by some suitable cutting device such as a cutting wheel. In mass production of the twine, one could apply the adhesive 10 to the web 6, superimpose thereupon the glass strands in a plurality of groups in parallel alignment. The web may be cut along the lines 18 and the web 6 may be folded over the top of the glass strands in either a butting or overlapping arrangement. This is more completely illustrated in Fig. 6. Therein one section of Fig. 5, which has been cut from the rest of the web, along at least one of the lines 18, illustrates the resin 10 coated on the web 6 and folded over in part and superimposed upon the resin covered strands 4. If one were to practice the process of the present invention by adapting the modification illustrated in Figs. 5 and 6, one could dispense with the need for the roller 11 and the upper web 2 but would need some conventional plow-like device to force the web 6 to fold up and over the top of the strands embedded in the resin before passing through the rollers 15 and 16 to produce the corrugated effect. Still further, the concept illustrated in Fig. 5 could be further modified by applying the glass strands along the web 6 in parallel alignment without any appreciable discontinuity between the groups of strands and by practicing the process as illustrated in Fig. 1, an upper web 2 could be applied to the assembly and the individual tapes out along lines such as those indicated by the symbol 18 prior to or subsequent to the passing of the complete assembly through the rubbercovered rollers 15 and 16. Fig. 7 illustrates a sectional view in part of the combined assembly of upper web 2, lower web 6, strands 4 and adhesive 10 prior to the passage of this combined assembly through the pressure rollers 15 and 16. It is to be noted that each group of filaments making up an individual strand of glass is completely surrounded by the adhesive material and each strand is kept separate from each other strand. It is to be further noted that since this tape has not been passed through the rollers 15 and 16, the corrugations have not, as yet, been produced. Fig. 8 illustrates the corrugated tape in an enlarged view, partially in section, which would be produced by passing a flat, composite tape comparable to that illustrated in Fig. 6 through the rollers 15 and 16. Again, it is to be noted that the individual strands 4 made up of the individual filaments are isolated from one another by the adhesive 10 which, in turn, protects the strands from direct contact with the web 6. The point 20 shows the butting of the edges of the web 6. Fig. 9 illustrates a substantially enlarged sectional view of one portion of Fig. 8, in which the filaments 19 making up the glass strand 4 are very numerous but it is to be noted that the filaments in one strand are isolated from the filaments in the next adjacent straud. The adhesive 10 not only separates the individual strands but also substantially protects the strands from direct contact with the paper webs 2 and 6. In Figure 10 the symbol 4 represents the glass strands, 6 represents the paper and 10 represents the adhesive bonding the glass strands and paper web together.

In the practice of the process of thepresent invention any adhesive material may be used to bond the paper web and glass strands together such as natural adhesives and synthetic resinous adhesives both thermosetting and a thermoplastic.

1,3,5-triazine and the like. Other thermosetting resins which may be used are those produced by the coreaction of an aldehyde with phenols; such as hydroxy benzene, Iesorcinol, bis-phenol and the like, or aldehydes reacted with ketones such as acetone, methylethyl ketone, diethyl ketone, ethyl propyl ketone, cyclohexanol and the like. Amongst the aldehydes which may be used in coreaction with any of the resin forming materials set forth hereinabove are acetaldehyde, propionaldehyde, crotonic aldehyde, acrolein and aromatic or heterocyclic aldehydes such as benzaldehyde, furfural and the like. Formaldehyde is generaliy the most commonly used aldehyde in correaction with these resin forming materials and is actually generally preferred.

Amongst the thermoplastic resin adhesives which may be used are polyvinyl acetate, the alkyl esters of alpha, beta unsaturated carboxylic acids such as polymethyi acrylate, polymethyl methacrylate, polybutyl acrylate, polybutyl fumarate, alkyd resins of the unsaturated or saturated type, either oil free or oil containing, modified with styrene or other vinylidene compounds, polyesters such as glycol succinates, or glycol sebacates, amide esters and the like.

Rubber adhesives, both natural and synthetic, may be used, such as the polymersof butadiene or copolymers of butadiene and styrene.

Amongst the natural adhesives which may be used are casein, soya protein and other proteins, starch, animal glue, gelatin, blood, asphalt, pitch and the like.

The tapes produced according to the process of the present invention, in and of themselves, are extremely strong and useful even without subjecting them to the twisting operation. in the preparation of the tapes for twine purposes, the paper should be tissue twisting paper whereas for non-twine purposes any paper may be used.

When these tapes are desired in the twine form, they may be twisted in a number of different ways, for instance, the tape may be passed through a water bath and then run directly to the twisting machine, or the tapes may be merely passed between heated rollers and directly twisted or as a further modification the tapes may be passed between a pair of parallel hot plates, and twisted directly. A still further modification can be accomplished by applying heat, such as in the manners indicated hereinahove, passed through a water bath and then twisted to form the twine or the tapes may be passed through a water bath, twisted to form the twine and then heated. A still further modification resides in that embodiment in which a water bath is used wherein a sizing material such as glue, flour, etc. is incorporated into the water bath. Still further, one could apply to the paper web a softener in the nature of an oil such as mineral oil, vegetable oil or the like.

A still further modification of the general process itself resides in the use of a third web of paper wherein a lower web, coated with adhesive is embedded with the parallel glass strands, a second web, coated with adhesive on both sides is superimposed thereupon, a second layer of parallel glass strands is embedded thereon and a top web is positioned to form a sandwich-like structure of paper, adhesive, glass strands, paper, adhesive, glass strands and paper.

The number of glass strands used across a given web is in no way critical. It is possible to vary the number of strands rather substantially depending on the width of tape or thickness of twine desired and depending further on the strength of tape or twine desired.

In the manufacture of the glass filaments, molten glass, maintained at a temperature of about 2500 F. is allowed to pass through about 204 dies to form glass threads which are drawn downward at about 6000 ft./rnin. A size coating is applied to the individual filaments. This coating serves to protect each individual filament from its companions in the strand whereby loss due to attrition is reduced to a negligible factor.

I claim:

l. A process for producing twine comprising the steps. of coating one face of a tissue paper web. with anadhesive material, by superimposingand imbedding on said web a plurality of adhesive material-coated glass fibrousstrands, in parallel alignment, covering the strand. inrbedded, adhesive coated web with a tissue paper web and uniting these components into a fiat assembly, thereafter twisting said assembly into a twine.

2. A process for producing twine comprising coating one face of a tissue paper web with an adhesive material, superimposing on approximately one-half of the width of said adhesive coated web, a plurality of glass fibrous strands, in parallel alignment, folding the paper so as to cover the strands to form a flat assembly, thereafter twisting said assembly into a twine.

3. A process for producing twine comprising coating one face of a tissue paper web with an adhesive material, superimposing on approximately one-half of the width of said adhesive coated web, a plurality of glass fibrous strands, in parallel alignment, folding the paper so as to cover the strands to form a flat assembly, pressing the folds of the paper web together so as to form corrugations with said strands and paper, thereafter twisting the paper-strand assembly into a twine.

4. A process for producing twine comprising coating one face of a tissue paper web with a thermosetting synthetic resinous adhesive, superimposing on approximately one-half of the Width of said resin coated web, a plurality of glass fibrous strands, in parallel alignment, folding the paper web so as to cover the strands to form a flat assembly, thereafter twisting said assembly into a twine and heating said twine so as to cure the resin.

5. A process for producing twine comprising coating one face of a tissue paper web with a thermoplastic synthetic resinous adhesive, superimposing one approximately one-half of the width of said resin coated web, a plurality of glass fibrous strands, in parallel alignment, folding the paper so as to cover the strands to form a flat assembly, thereafter twisting said assembly into a twine.

6. A process for producing a glass strand and paper twine comprising the steps of coating one face of a tissue paper web with an adhesive material, superimposing and embedding on approximately one fourth of the paper web on each side of the center of said web, a plurality of glass fibrous strands in parallel alignment, folding over both sides of the web not covered with strands onto the center portion of the web covered with the strands, uniting into a fiat assembly, thereafter twisting said assembly into a twine.

7. A process for producing glass-paper twine comprising coating one face of a tissue paper web with an adhesive material, superimposing and embedding on said adhesive coated web a plurality of glass fibrous strands, in parallel alignment, covering the strand embedded adhesive coated web with a second tissue paper web, and uniting these components in a substantially flat assembly, thereafter twistin said assembly into a twine.

8. A thermosetting resin coated paper-glass strand twine comprising a plurality of spirally parallel glass strands positioned between at least two layers of twisted tissue paper and embedded in a thermosetting synthetic resin.

9. A thermoplastic resin coated paper-glass strand twine comprising a plurality of spirally parallel glass strands positioned between at least two layers of twisted tissue paper and embedded in a thermoplastic synthetic resin.

it). A composite cord formed from a tape comprising a plurality of parallel glass strands positioned as a layer of substantially single strand thickness between at least two layers of paper and adhesively bonded to said paper, said tape being twisted into cord configuration wherein substantially all of said glass strands are maintained in spirally parallel relationship in a single layer between any given two layers of said paper.

11. Aprocess for producing twine comprising forming a tape by combining two layers of paper and a plurality of glass strands positioned therebetween in parallel relationship in a layer of substantially single strand thickness, adhesively bonding said strands to said paper and thereafter twisting said tape into a twine.

References Cited in the file of this patent UNITED STATES PATENTS Cohoe Oct. 10, 1939 Fay Aug. 18, 19,42 Horstrnan Sept. 19, 1950 Mathes July 22, 1952 Slayter et al. Dec. 29, 1953 Slayter Mar. 9, 1954

Claims (1)

1. A PROCESS FOR PRODUCING TWINE COMPRISING THE STEPS OF COATING ONE FACE OF A TISSUE PAPER WEB WITH AN ADHESIVE MATERIAL, BY SUPERIMPOSING AND IMBEDDING ON SAID WEB A PLURALITY OF ADHESIVE MATERIAL-COATED GLASS FIBROUS STRANDS, IN PARALLEL ALIGNMENT, COVERING THE STRAND IMBEDDED, ADHESIVE COATED WEB WITH A TISSUE PAPER WEB AND UNITING THESE COMPONENTS INTO A FLAT ASSEMBLY, THEREAFTER TWISTING SAID ASSEMBLY INTO A TWINE.

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