US3317021A - Ribbons and methods of making same - Google Patents

Description

May 2, 1967 J. LEACH RIBBONS AND METHODS OF MAKING SAME Filed April 2, 1963 INVENTOR. L/cve fic/ef United States Patent O 3,317,021 RIBBONS AND METHODS F MAKING SAME Jack Leach, Greensboro, N.C., assignor to Burlington Industries, Inc., Greensboro, N.C., a corporation of Delaware Filed Apr. 2, 1963, Ser. No. 270,097 Claims. (Cl. 197-172) The present invention relates to cert-ain improvements in ink-carrying ribbons for use in typewriters, c-omputers and like printing devices.

There have been numerous prior proposals for the purpose of providing improved inked ribbons for use in typewriters or equivalent printing equipment. These prior proposals have involved the use of a variety of textile materials including `conventional nylon yarn as well as crimped or distorted nylon yarn (see, for example, U.S. Patent 2,918,160). While certain of these proposals have offered some improvement over prior types of inked ribbons, there is still a real need in the art for inked ribbons having better wear, ink-retaining capacity and clarity of print. This need is particularly evident yat the present time where high speed typewriters, computers and the like place extremely severe requirements and conditions of use on inked ribbons used therein,

The principal object of the present invention is to provide a new and improved inked printing ribbon for use with typewriters, computers and the like. A more specific 4object of the invention is the provision of an inked printing ribbon which is characterized by substantially increased useful ink capacity and ink transferability with subsequently longer Wear life and the capability of printing sharp and clear characters even with the fastest types of printing devices. `Other objects will also be hereinafter apparent from the following detailed description of the invention.

:Broadly stated, the inked ribbon of the invention comprises a closely woven fabric having a uniformly puckered or shrivelled surface and comprising stretch multifilament synthetic thermoplastic polymeric yarn, typically nylon, made by false twisting and heat treating the yarn as described below. The lbest results `are obtained when -both the filling and warp comprise this special type of stretch yarn although there is a possibility of using conventional non-stretch synthetic thermoplastic, multilament yarn as the war-p the filling and Warp in any case preferably having the same composition. Normally, nylon yarn is used for the filling and Warp, but, as an alternative, appropriatepolyester yarn (e.g., Dacron polyethylene terephthalate) may be used in lieu of, or in addition to, the nylon yarn as long as it is a stretch yarn as contemplated herein.

The success of the invention is due to a number of unique features in the fabricating and finishing of the ribbon. For one thing, the ribbon of the invention is characterized by the fact that the surface thereof, rather than being smooth or fiat as generally the case, is uniformly puckered or roughened so that, in a sense, the

ribbon is three-dimensional. Stated another way, the invention contemplates pores or pits in the fabric surface itself. These surface irregularities are distinguishable from, and in addition to, any pores or cavities which may be formed by mere distortion of individual filaments of the stretch yarn which do not disrupt the fabric surface.

The puckered or pitted fabric surface contemplated herein offers a number of unique Iadvantages over prior ribbon structures. For example, the present ribbon has a substantially greater useful ink-retaining capacity. Additionally, the puckers or pores in the surface of the ribbon tend to expand and otherwise mold themselves tightly about the typing face or font to give a much clearer printing impression than otherwise possible. At the 3,317,021 Patented M ay 2, 1967 ice been false twisted, heated in the twisted state 4and subsequently heat annealed by dry heating at elevated temperature, eg., from 325 to 460 F. for 0.2 to 1.5 seconds. Yarns of this type are commercially available and may be prepared by processing a synthetic linear polyamide (nylon) or polyester (typically Dacron) in conventional fashion. One example of a stretch -nylon yarn especially suitable for use herein both as warp and filling is that available under the trade name Saabaf It has previously been proposed to use conventional nylon yarn (e.g., 40denier, 'S4-filament nylon yarn) and even distorted or crimped nylon yarn (U.S. lPatent 2,918,160) in the preparation of inked ribbons. These materials will give some improvement over other earlier efforts but according to the invention, it has been found that the Saaba type of stretch yarns (i.e., those which have been prepared by false twisting, heat set or annealed in the twisted state and subsequently further heat treated in yarn form), especially when used in both filling and warp, in the manner prescribed herein, give uniquely better results.

Another important aspect of the invention is that the ribbon is woven much more closely than conventional ribbon constructions. Thus, the present ribbon construction .generally includes 10-50% more Warp ends and picks than conventional ribbon fabric. As an illustration, conventional ribbon fabric using Lf0-denier, 34-filarnent nylon yarn usually includes something around 2-60-270 ends per inch (e.g., -110 filling ends and 150-1701warp ends or as another example 88-90 filling ends and 180 warp ends). In contrast, the present ribbon, using 40/34-stretch nylon yarn of the type required herein, would include from about 300-365 ends per inch, with the filler count at least per inch.

As will be appreciated, it is difficult to specifically define the closer weave used herein by reference to total picks and ends since this total is obviously dependent upon the yarn size. However, as a further illustration of the compactness of the present weave, it can be stated that the cover factor of the present products (e.g., a 1 x 1 plain weave) generally runs at least 10% higher and usually in the neighborhood of 15-30% higher than the cover factor for the same fabric using a standard number of picks and ends. In the present fabric, the ends are woven so close together that there is minimal spacing between adjacent picks and adjacent ends and there is sufficient compression of the ends after the finishing operation to give the uniform fabric puckering or shrivelling which characterizes the present ribbon. During the finishing operation, adjacent filling and warp ends are drawn together and there is a tendency because of the close or tight weave, for ends to ride up on each other as the puckers are formed. Roughly speaking, the puckered portion may comprise from 80 to 100% of the total surface area of the fabric.

Apart from the more compact weave using a specific type of stretch yarn, the fabric of the invention may be woven in conventional manner using standard equipment. It is, however, a further feature of the invention that the stretch yarn used herein is kept under tension during the weaving operation, the tension being sufficient to stretch the yarn to its maximum length (usually 200 to 300% of its relaxed length).

As indicated, there are certain nishing operations which are also essential to the success of the invention. Thus, after the fabric has been woven, it is taken from the loom and exposed in the fully relaxed condition to Water containing a detergent, such as Triton X-100` (basically isooctyl phenyl polyethoxy ethanol) and a neutralizing agent, e.g., sodium carbonate at 175 F. to 200 F. This treatment usually takes from 15 to 45 minutes and results in a shrinkage of the fabric dimensions, and the formation of the above-mentioned uniform puckering on the fabric surface. The actual degree of shrinkage will vary widely depending on fabric construction but usually will be in the order of to 30% of the original width and length. Thereafter, the fabric is dried, e.g., frame dried, at 220 to 235 F., under tension at predetermined width. The fabric is then exposed to another heat treatment (dry heat) at a temperature higher than the vdrying temperature (e.g. 350` to 400 F.) with the fabric held at the proper Width so as to set the fabric. These drying and setting operations further emphasize and permanently set the pucker effect developed in the initial treatment with water. Careful control of the weaving and finishing operations insure that this puckering is uniform throughout the fabric.

After the above finishing operations, the fabric may be cut into ribbon form and inked in conventional fashion. Because of the rough or puckered surface of the ribbon, it will satisfactorily retain substantially more useful ink than hitherto possible, e.g. the inked ribbon may contain 25 to 30% ink, based on the weight of dry uninked ribbon. This greater ink pickup occurs Without the usual problem of wetness of ribbon or ink spraying upon impact by the type bar itself. Furthermore, due to the entrapment of the increased ink pickup, the ink life of the present ribbon is longer than that of prior products and the intensity of prints obtained therefrom is maintained at a higher degree for a longer period of time. As noted heretofore, it is a characteristic feature that the ribbon is readily extended and shaped under the pressure of, for example, 'a typewriter type bar, so that it molds itself firmly about the type face thus giving an extremely sharp and clear print. At the same time, however, the resilience of the ribbon is such that as soon as the type is moved away, the ribbon returns to its original puckered shape ready to mold about the next key that strikes this same surface. This feature is of especial importance and significance in conjunction with modern high speed typewriters and computers.

The invention is illustrated by the following examples:

Example 1 A fabric (53 inches wide and 300 yards long) was Woven in a plain 1 x 1 weave using 176 ends per inch of SO-denier, 26-filament Saaba stretch nylon yarn with a twist of 7 turns in the S direction as the warp and 120 picks per inch of C50-denier, 26-filament Saaba stretch nylon yarn with 4 turns S in the filling.

The Saaba yarn used herein is prepared by false twisting on a Universal 550 machine using a spindle speed varying between 40,000 and 240,000 r.p.m.s with an average speed of approximately 150,000 r.p.m.s at the rate of 95 to 130 turns per inch with an average of 121 turns per inch While heating the twisted yarn in a heat range from 350 to 440 F. and -at rate of 25-50` yards per minute to give an exposure time of 0.21.5 seconds after which the heat set yarn is subsequently annealed in a temperature of 325 to 460 F. for approximately the same length of time. During this latter process the yarn is overfed into the twisting unit at a rate varying 0.2 to 1.8% in a rate range of to l117 yards per minute. An appropriate size, eg., polyacrylic acid may be applied to the yarn to facilitate weaving.

After weaving, the fabric was immersed in the fully relaxed state in water containing 0.1% by weight Triton X-100 as a detergent. This treatment was carried out at 200 F. for 30 minutes and resulted in a uniformly puckered fabric with a shrinkage of 20%in the width and 10% in the length. Thereafter, the fabric was frame dried at 51 Width and 260 and then heated at a temperature of 350 F. for one minute while held under tension (0.5 grams per denier) at the desired dimensions (50 width and 8% length shrinkage). The resulting fabric, which retained the uniform pucker developed in the water treatment, was then slit into ribbons and 28% ink applied thereto based on the weight of the pre-inked ribbon. The inked ribbon was highly suitable for use as a tyewriter ribbon because of its wear, ink ickup and type molding characteristics.

The above process was repeated in the following examples using the indicated warp and filling combinations:

Example 2 Warp: 40/ 34 semi-dull nylon (T-200) 7 turns Z. Filling: 40/ 34 Saaba nylon 31/z-Z.

Example 3 Warp: 30/26 semi-dull nylon 7-Z. Filling: 30/26 Saaba nylon.

Example 4 Warp: 20/=17 semi-dull nylon 10-Z. :Filling: 20/ 17 Saaba nylon.

Example 5 Warp: 30/26 stretch nylon 7-S. Filling: 30/ 26 stretch nylon 7-S.

Example 6 Warp: 30/26 stretch nylon 7-S. IFilling: 30/26 stretch nylon 4-S.

Example 7 Warp: 40/ 34 semi-dull nylon (T-200) 7-Z. Filling: 70/ 34 stretch nylon 4-S.

Example 8 Warp: 40/*34 semi-dull nylon (T-200) 7-Z. lFilling: 40/ 34 stretch nylon 4-S.

Example 9 Warp: 30/26 semi-dull nylon (T-200) 7-Z. Filling: 30/26 stretch nylon 76.

The stretch yarn referred to above in Examples 5-9 is yarn prepared essentially in the manner of Saaba yarn, i.e., by false twisting and heatsetting in the twisted state followed by heat annealing in the untwisted form in order to control the degree of sh-rinkage to be achieved in ultimate cloth shrinkage. The semi-dull nylon yarn referred to in Examles 2, 3, 4, 7, 8 and 9 is conventional non-stretch nylon yarn.

The invention is further illustrated by the accompanying drawings wherein:

FIGURE 1 is a perspective view of a spool of inked printing ribbon according to the invention;

FIGURE 2 is an enlarged plan view of t-he ribbon showing the tight weave thereof;

FIGURE 3 is a sectional view taken along the lines 3-3 of FIGURE 2; and

FIGURE 4 is a plan view of the ribbon showing the puckered surface effect.

As shown, the ribbon Z is rolled up on a spool 4 and comprises a closely woven fabric made up of stretch lling yarns Il5 and warp yarns 8 of the type indicated above. It will be noted from the expanded view of FIGURE 2 that the weave is such that after the finishing operation, there is essentially no sace between the warp and filling ends and the ends shrink sufficiently to effect the desired uniform pucker or distortion in the fabric surface as shown in FIGURE 4.

It will be appreciated that various modifications may be made in the invention described herein Without deviating from the scope thereof as set forth in the following claims.

I claim:

1. Aninked ribbon for use in a printing device comrising tightly woven synthetic multilament thermoplastic stretch yarn, the surface of said ribbon being uniformly puckered whereby the wear and ink capacity of said ribbon are increased, the puckers in said fabricsurface being extensible so as to mold around the printing element in said device.

2. A ribbon according to claim 1 comprising warp and filling yarns which are stretch nylon yarns.

3. A ribbon according to claim 1 comprising warp and filling yarns which are stretch polyester yarns.

4. A ribbon according to claim 2 wherein the stretch yarns are prepared by false twisting, heat setting in the twisted condition and then heat annealed in the untwisted state, the heat setting and heat annealing being carried out with dry heat at 325-460 F. for from 0.2 to 1.5 seconds.

l5. Aribbon according to claim 1 wherein the puckered portion comprises 80-100'% of the total fabric surface.

l6. A ribbon according to claim 5 wherein the ink content is `2530%, based on the weight of dry, un-inked ribbon.

y7. A .ribbon according to claim .1 wherein the total number of yarn ends per inch is from -50% kgreater than standard inked ribbon construction.

8. A ribbon according to claim 7 wherein lthe weave is such that there is essentially no open space between adjacent ends.

9. A ribbon according to claim .1 wherein the woven warp and filling yarns are puckered by immersing the same in water in the relaxed state.

10, The method of preparing an inkced printing ribbon which comprises preparing a tightly woven fabric from a synthetic thermoplastic multilament stretch yarn, thereafter immersing the Woven fabric in water in the relaxed state to shrink the fabric and produce a uniformly puckered surface thereon and then `drying and setting said fab-ric.

References Cited by the Examiner UNITED STATES PATENTS 1,904,628 4/1933 Pelton 197-172 2,054,091 9/1936 McElrath 197-1=72 2,054,264 9/1936 Mollert 197172 2,467,449 4/ 1949 Whitehead 197-172 2,495,847 1/1950 Kerr '1139-421 2,564,245 8/1951 Billion 57-157 2,810,184 10/'1957 Sherman 139-421 X 2,918,160 12/1959 Thompson 197-172 3,022,880 2/1959 Newman 197172 3,041,813 7/1962 Enneking 57-34 3,091,912 6/1963 Stoddard et al. 5734 X 3,131,528 5/'1964 Scragg 57157 X FOREIGN PATENTS 582,693 11/ 1946 Great Britain. `850,693 10/ 1960 Great Britain.

OTHER REFERENCES Websters Third New International Dictionary, latest unabridged, G. & C. Merriam Co., p. 1837.

ROBERT E. PULFREY, Primary Examiner. E. WRIGHT, Assistant Examiner,I

Claims (1)

1. AN INKED RIBBON FOR USE IN A PRINTING DEVICE COMRISING TIGHTLY WOVEN SYNTHETIC MULTIFILAMENT THERMOPLASTIC STRETCH YARN, THE SURFACE OF SAID RIBBON BEING UNIFORMLY PUCKERED WHEREBY THE WEAR AND INK CAPACITY OF SAID RIBBON ARE INCREASED, THE PUCKERS IN SAID FABRIC SURFACE BEING EXTENSIBLE SO AS TO MOLD AROUND THE PRINTING ELEMENT IN SAID DEVICE.

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